Smile Design

Presented by:
Dr. Jehan Dordi
3rd Yr. MDS
SMILE DESIGN
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CONTENTS
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• Terminologies
• Introduction
• Reference frames for orientation
• Lip lines
• Gold proportion
• Smile dominance
• Perceptual aspects – the art of illusion
• Cosmetic Contouring
• Smile design: Clinical assessment, analysis and consideration
• Porcelain laminates and veneers: Clinical assessment and analysis

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• Colour
• Shade selection
• Dental bleaching
• Esthetics with composites
• Metal ceramic and all ceramic restorations
• Implant – esthetics
• Perio – esthetics
• Ortho – esthetics
• Recent advances in smile design in prosthodontics
• Review of literature
• Conclusion
• References

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• Dental esthetics: In dentistry, the theory and philosophy that deal with beauty
and the beautiful, especially with respect to the appearance of a dental
restoration, as achieved through its form and/or color; those subjective and
objective elements and principles underlying the beauty and attractiveness of an
object, design, or principle.
• Smile designing: A concept of using gender, personality, and age as factors in
tooth arrangement and anatomy by means of waxing of casts, interim composite
resin on teeth, or digital image enhancements
• Cosmetic dentistry is application of the principles of esthetics and certain
illusionary principles, performed to signify or enhance beauty of an individual
to suit the role he has to play in his day-to-day life or otherwise.

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• In our modern times, a pleasing appearance often means the difference between
success and failure in both personal and professional lives.
• Scottish dentist Charles bell quoted that “the thought is to the word that the
feeling is to the facial expression.” He pointed out that a smile could convey a
thousand different meanings, yet it is the most easily recognized expression.
• Smile plays a major role in how we perceive ourselves, as well as the
impressions we make on the people around us.
• Smile is dependent on the musculature and the presence of the teeth. But every
person is not fortunate enough to have a beautiful smile. The answer to the
above problem is the esthetic dentistry and smile design which has developed
leaps and bounds with the latest technologies and materials.

REFERENCE FRAMES FOR
ORIENTATION
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• The anatomical elements of the face and the biological elements that include the
functional and phonetic elements, provide the reference frames, guidelines and
points.
• These elements help the dentist to achieve a general sense of orientation and
diagnosis.
• References can be classified as
1. Horizontal references,
2. Vertical references,
3. Sagittal references and
4. Phonetic references.

Horizontal references:
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• The horizontal perspective of the face is provided by the interpupillary line the
commissural line.
• The inter-pupillary line helps to evaluate the orientation of the incisal plane, the
gingival margins and the maxilla.
• An imaginary horizontal line through the incisal plane and the gingival margins
should be visibly parallel to the inter-pupillary line. This helps to diagnose any
asymmetry in the tooth position or gingival location.

Vertical references:
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• The facial midline serves to evaluate the location and axis of the dental midline
and the medio-lateral discrepancies in tooth position.
• The inter-pupillary line and the facial midline emphasize the ‘T’ effect in a
pleasing face.
• Axial inclination is the direction of the anterior teeth in relation to the central
midline and becomes progressively more pronounced from the central incisor to
the canine.

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• There is a definite mesial inclination to all the anterior teeth related to the
midline. The axes of the premolars and the first molar on either side also show
mesial inclination in relation to the midline.
• The perception of tooth inclination can be viewed from the frontal aspect
around the central vertical midline, which acts like a fulcrum around which
axial inclination of teeth on either side exhibit a phenomenon of balance of
lines.
• Natural smiles show a deviation from these standard axial inclination.
Deviations in axial inclination cause a visual tension when beyond the point of
equilibrium.

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Sagittal references: Soft tissue analysis at a standardized position helps in
studying the profile of an individual.
• The lip protrusion, the amount of prominence of chin, recession or prominence
of the nose and its degree, all help in profile analysis for diagnosis and
treatment planning.
• The E-line or esthetic line is an imaginary line connecting the tip of the nose
to the most prominent portion of the chin on the profile, ideally the upper lip is
1-2 mm behind and the lower lip 2-3mm behind the E-line.
• Any change in the position of the E-line indicates the abnormality in the upper
or lower lip position.

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Phonetic references: Phonetics play a part in determining maxillary central
incisor design and position.
• ‘F’ and ‘V’ sounds are used to determine the tilt of the incisal third of the
maxillary central incisors and their length.
• The ‘M’ sound is used to achieve relaxed rest position and repeated at slow
intervals can help evaluate the incisal display at rest position. ‘S’ or ‘Z’ sounds
determine the vertical dimension of speech.

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• The length, the curvature and the shape of the lips significantly influence the
amount of tooth exposure during rest and in function.
• The average maxillary incisor display with the lips at rest is 1.91mm in men and
3.40 mm in women.
• Patient’s with short upper lips and younger patients generally display more
maxillary tooth structure which may be up to 3.65mm.
Lower lip line
• It helps to evaluate the buccolingual position of the incisal edge of the maxillary
incisors and the curvature of the incisal plane.

Upper lip line
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• It helps to evaluate the length of the maxillary incisor exposed at rest and
during smile and the vertical position of the gingival margins during smile.
• The upper lip line can be classified as low, medium or high depending upon the
amount of tooth or gingival display that is available at rest of during a moderate
smile.
• It helps to evaluate the length of the maxillary incisor exposed at rest and
during smile and the vertical position of the gingival margins during smile.
• The upper lip line can be classified as low, medium or high depending upon the
amount of tooth or gingival display that is available at rest of during a moderate
smile.
• A smile can be termed “toothy” if more than 6mm of incisal display is seen at
rest position or “gummy” if more than 3mm of gingival tissues are displayed in
moderate smile.

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• When mathematics is applied to the study of ideal tooth form, a numerical
relationship is established within a single tooth form (ideal proportion) and also
between a series of teeth in the arch (relative proportion).
• The position of the tooth in the arch, the relationship between the width, the
length and the face of the tooth can also be numerically established in relation
with certain anatomic landmarks.

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• Gold Proportion is expressed in numerical form and applied by classical
mathematicians such as Euclid and Pythagoras in pursuit of universal divine
harmony and balance.
• It has been applied to a lot of ancient Greek and Egyptian architecture and may
be expressed as the ratio 1.618:1.
• If the ratio is applied to the smile made up of the central, lateral incisor and the
mesial half of the canine, it shows that the central incisor is 62% wider than the
lateral incisor which in turn is 62% wider than the visible portion of the canine
which is the mesial half, when viewed from the front.

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• Application of sizing the central incisors from certain facial measurements is
known as the 1 to 16 theory, whereby the height of an ideal maxillary central
incisor from the incisal edge to the gingival crest is 1/16th the distance from the
inferior border of the chin to the inter papillary line.
• The same tooth width can be measured from the mesial to distal contact areas
and is 1/16th of the distance measured from either zygomatic prominence
through an imaginary facial midline.
• The distance between the posterior border of the papilla to the outer labial
surface of the central incisor averages to about 12.5mm with a variation of
approximately 3.8mm.

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• The end of the first palatal rugae is located 1.5 mm to 2mm from the lingual
surface of the canine.
• The average distance between the base of the sulcus and the tip of the maxillary
incisor is measured 22mm. This helps the dentist to determine the tooth position
in the vertical plane.
• For harmony, certain symmetries are essential while certain asymmetries are
acceptable.
• The natural pleasing smile may not necessarily comply with all rules of
symmetry or golden proportion or may not exhibit perfect balance without
irregularity of shape.

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• In certain cases, the most predominantly striking features of a face are the
smile; these are the “Dominant Smiles”.
• The distinguishing characteristics observed in people with pleasant smile
dominance that can be used as a guideline for creating the same are:
• The maxillary central incisors exhibit a strong presence by their size and form
reflecting the personality of the individual.
• The maxillary lateral incisors and the canines complement the central incisor in
terms of proper shape and form.

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• Smile recurring ratios are observed in the teeth from the central incisor to the
premolar.
• Well coordinated movements of the lips with the other peri-oral musculature
and corresponding harmonious facial expressions, contribute to the pleasant
face during smile.
• The complexion and texture on the face contrast with the lip color, gingival and
the teeth leading to a distinct demarcation between the oral and the facial frame.

PERCEPTUALASPECTS – THE ART OF
ILLUSION
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• Illusion is a figment of imagination where a perception of an object is created.
Fundamentals and Principles
• The art of creating illusions consists of changing perception, to cause an object
to appear different from what it actually is.
• Teeth can be made to appear smaller, larger, wider, narrower, shorter, longer,
younger, older, masculine or feminine.
• Illusion works on two basic principles which are the principle of illumination
and the principle of light. The most important of these is the perception that
light approaches and dark recedes.

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• This is termed as the ‘Principle of Illumination”. The second artistic
predilection of great importance in dentistry is the use of horizontal and vertical
lines and ridges.
• Horizontal lines make the object appear wider and vertical lines make the object
appear longer. This is termed as the “Principle of Line”.
• The artistic predilection exhibited in the principle of illumination can be
maintained to change the size, shape and the overall form of the tooth through
illusions.

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• Cosmetic contouring by definition is the reshaping of natural teeth to make
them esthetically pleasing.
• In natural dentitions, variations seen in tooth shape and size some times violate
the acceptable width to length ratios as well as the golden proportion.
• Minor adjustments in contours to change the perception of these proportions
increases the esthetic acceptability to a great extent.
• It is indicated for giving a pleasing appearance to fractured, chipped, extruded,
malformed or over lapped teeth .

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• The procedure is contraindicated in hypersensitive teeth, teeth with thin or
defective enamel formation or large pulp chambers.
• The upper lip line should be used as a reference to see how much tooth is
visible when the patient smiles.
• The lower lip line will help to create a pleasing smile line. Tooth visibility with
lips at rest, when the patient talks or smiles should also be assessed. The dentist
should view the patient in sitting and standing positions.

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Procedure:
• The procedure involves minimum tooth reduction confined to enamel.
• Changes on the tooth surface of the related tooth are carried out by working on
the transitional line angels, height of contour, incisal and facial embrasures and
adjusting incisal edge and angles.
• Finishing disks are used to open incisal embrasures and the reshaped teeth are
then thoroughly polished with a fine grit diamond paste and application of
fluoride gel or foam is recommended to minimize any chances of postoperative
sensitivity.

SMILE DESIGN-CLINICALASSESMENT,
ANALYSIS & CONSIDERATIONS
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Dento-Facial analysis
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Facial and dental Midlines
• A note of facial midline is necessary to understand the concept of dental
midline.
• Facial midline has been defined in many ways, Donovan et al defined it as
vertical line, drawn through the forehead, nose columella, dental midline, and
chin. It also represents an imaginary line that runs vertically from the nasion,
subnasal point, interincisal point and the pogonion.

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• The facial mid-line is located in the center of the face, and it is perpendicular to
the interpupillary line.
• Midline is considered perfect when it end up with the facial midline. It should
be 90 degrees to the incisal plane.
• Among existing all the esthetic elements dental midline abnormalities are least
observed by both patients and dental personnel.

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• Commonly midline discrepancies of up to 4 mm will not be perceived as
unaesthetic.
• Midline can be assessed by using anatomical guides such as midline of the
nose, forehead, chin, philtrum, interpupillary plane.
• Among all the available anatomic land marks philtrum of the lip is the most
precise guide and it is always in the middle of the face except in some
conditions such as surgery involving the lip or cleft lip or accidents.

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• The center of the philtrum forms the middle of the cupids bow and should
correspond to the papilla between the two central incisors.
• When center of the philtrum conforms to interdental papilla midline is incorrect
then difficulty is in incisal inclination.
• On contrary, if the philtrum and papilla do not correspond to each other, then
problematic true midline shift can be observed.
• Noticeable midline is the one which does not bisect the papilla rather than the
one that does not bisect the philtrum.

Dento-Labial Analysis
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• This step is mainly concerned with the evaluation of the relationship of the teeth
to the lips and, mainly focuses on visual display of teeth in static and dynamic
conditions. It also includes the assessment of the buccal corridor.
Incisal Length
• The incisal edge of the maxillary central incisor is the most vital element in the
creation of a smile.
• When it is set, it serves to decide the best possible tooth proportion and gingival
level; hence, setting the incisal edge is particularly imperative.

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• The parameters such as degree of tooth display, phonetics and patient inputs are
used to set up the maxillary incisal edge position.
• An incisal third of the upper central incisor measuring 3.5 mm should be
noticeable when the mouth is relaxed and lips are at rest. However, an increase
in age reduces muscle tonus resulting in less tooth display.
• The patients who have enhanced esthetics as the main objective of treatment, a
3mm-4mm tooth display at rest are considered esthetically ideal.

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• With a specific goal to decide appropriate lip, tongue and incisal backing and
tooth position, it is fundamental that the patient sits either erect or stands during
the phonetic movements.
• Composite resin mock-ups of the desired length, diagnostic waxing, and
computer imaging, provisional restorations set-ups should be used as helps and
guides for communication with the patient.

Tooth dimensions in esthetics
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• Facial morphology is critical in deciding correct dental proportion which is
intern important in creating an esthetically attractive smile.
• Central incisors are the key to the smile and proportions must be
mathematically and esthetically precise. The ratio of width to length of centrals
should be nearly 4:5.
• Additionally, appearance and placement of the laterals and canines is governed
by the shape and location of the central incisors.

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Several guidelines have been proposed for creating correct proportions in an
esthetically attractive smile based on perceived proportions viewed from the
facial aspect. These include; golden proportion, recurring esthetic dental
(RED) proportions, M proportions and Chu’s esthetic gauges.
• Recurring esthetic dental proportion (RED): When moved posteriorly from
midline, the consecutive width proportion viewed from facial aspect must
remain constant.
• This provides marked flexibility of agreement between tooth properties and
facial proportions.

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• M proportions: This method involves the use of computer software program to
compare the tooth width with the facial width.
• Chu’s esthetic gauges: This method is based on Levin’s RED concept and
utilizes a series of gauges to make intraoral analysis. The gauges permit
diagnosis of problems associated with tooth width, tooth length and gingival
length discrepancies.

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Factors governing individual tooth dimensions are as below:
• Maxillary central incisor’s estimated length should be 10-11 mm and the
computed width should fall within the ratio between 75 - 80%. Incisors are the
crucial point of an esthetic smile and produce the central dominance.
• Maxillary lateral incisors are the lively part of the smile. They render
individuality, never symmetrical and impact gender characterization.
• Maxillary canine play a vital point in making a pleasing smile as they are
situated at the junction between the anterior and posterior dental segments;
hence, only the mesial half of the canine is visible from the frontal view when
the patient smiles. Canine portrays the personality characterization.

Buccal Corridor
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• It refers to negative (dark) space between the buccal surface of upper posterior
teeth and the inside of the cheek (corner of the mouth) visible during smile
formation.
• Buccal corridor is influenced by the various factors such as;
• The width of the smile and upper arch,
• Tonicity of the facial musculature,
• Placement of the labial surface of the upper premolars,
• Disto-facial line angle
• Canine prominence and
• Incongruity between the value of the premolars and the six anterior teeth

Zenith points
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• These are the most apical points of the clinical crowns demonstrating height of
contour, where most of the gingival scalloping is found.
• It is positioned slightly distal to the perpendicular line drawn down the center of
the tooth.
• But for the lateral incisor zenith point may be centrally situated, making it an
exception.
• The importance of the zenith points lies while closing diastemas and/or
changing the distal or mesial inclination of the teeth.

Tooth inclinations
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• Axial inclination relates to the vertical alignment of upper teeth, noticeable in
the smile line, to central perpendicular midline.
• From the central incisors to the canine, there should be regular, progressive
increase in the mesial inclination of each successive front tooth.
• Upper central incisor is placed vertically or somewhat labial. Whereas upper
lateral incisor’s cervical area is tucked in and incisal edge inclined somewhat
labially.
• Maxillary canine is placed in such a way that the cervical area positioned
labially with cusp tip lingually angulated.

Inter-tooth Relationships
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Interdental contact area and point
• It is defined as the broad area in which two neighboring teeth contact each
other. It follows the 50:40:30 rule in reference to the maxillary central incisor.
• The increasing ICA helps to create the impression of longer wider teeth and also
extend apically to remove black triangles.
• Interproximal contact point refers to the most incisal aspect of the interdental
contact area. Rule of thumb is that interproximal contact point moves apically
as one move farther backwards form the midline.

Incisal embrasures
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• The incisal embrasures should exhibit a natural, gradual increase in depth from
the central to the canine.
• This is due to the anatomic positioning of the contact points as they move
apically from central to canine.
• These contact points in their apical movement should imitate the smile line.

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Symmetry and balance
• Symmetry is the proportionate arrangement of several features with respect to
each other.
• For central incisors balanced length and width is most crucial feature of central
incisors. It becomes less concerned as moved further away from the midline.
• Static symmetry refers to mirror image of the upper central incisors, whereas
dynamic symmetry stands for two similar but distinguishable image.
• The right and left sides of the smile are said to be well balanced when the
balance is apparent as the eyes move distally from the midline.

The relationship of the teeth to the gingiva
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• Gingival health is of utmost significance so that the gingival tissues should be
in a state of complete health before the start of any treatment.
• Setting up precise gingival levels for individual tooth is significant in making
balanced smile.
• In the cervical region of the central incisors gingival level should be bilaterally
symmetrical and it should match the canine.
• However, gingival level of lateral incisors should be at cervical to that of
centrals and canines.

Cervical embrasure
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• Embrasures located cervical to the interproximal contact area are referred as
cervical embrasures.
• The darkness of the oral cavity that is visible in the interproximal area between
the gingiva and the contact area is known as black triangle.
• These are noticeably unaesthetic and negatively affects individual’s smile.
• It is always mandatory to avoid black triangles by considering most apical area
of restoration of 5mm or less from alveolar crest to encourage the formation of
healthy pointed interdental papilla

Smile line
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• Smile line denotes an imaginary line along the incisal edges of the upper front
teeth that should follow the curvature of the upper border of the lower lip when
smiling.
• Smile line advocates that the centrals should look slightly longer, or equals to
the canines along the incisal plane.
• Lip line refers to the location of the inferior border of the upper lip during
smiling and thereby defines the display of tooth or gingival interface.
• Gingival margin and lip line should be corresponding to each other or there can
be 1-2mm display of the gum tissue.

Dimensions of color
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• Color cannot be perceived without light, which is a form of electro-magnetic
energy visible to the human eye.
• The visible spectrum of light lies in a narrow band of 380nm to 760nm.
• It has the ability to stimulate the cells in the retina which is interpreted by the
brain, discerning the sense of color.

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• Clark stated that “Color, like form, has three dimensions”. Hue, which is the
name of the radiant energy, Chroma, which is the saturation of the hue and
value, which is the relative lightness or darkness of the color.
• Since clinical color matching depends upon the ability of the dentist to perceive
the difference in the tooth shade guide comparison; complete understanding of
the color dimensions is critical.

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• The Munsell color order system best serves the needs of the dental profession in
its tempt to visualize and organize color.
• Hue: In Munsell’s words, “It is that quality by which we distinguish one color
family from another”.
• Generally there are six hue families. Violet, blue, green, yellow, orange and red.

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• Chroma: In Munsell’s words, “it is the quality by which we distinguish a
strong color from a weak one. “Human teeth fall into the yellow to yellow red
area of the Munsell color order system. Pale colors have a low chroma whereas
intense colors have high chroma.
• Value: Value or brilliance is the relative blackness or whiteness of color. On a
scale of black to white, white has “high value”, black a “Low value” and
Midway between black and white is the medium grey. Value is the only
dimension of color that can exist by itself.

Opacity and Translucency:
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• As light strikes a surface, it is either totally reflected, totally absorbed or a
combination of both.
• Opaque objects reflect all or most of the light that is incident on them whereas
transparent objects transmit all of the light that is incident on them.
• When part of the light incident on an object is transmitted, while the rest is
scattered, the property of the object is known as translucency. It decreases with
increasing scattering within the materials.

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• Translucency, in effect, is the three dimensional spatial relationship or
representation of value.
• Highly translucent teeth tend to be lower in value, since they allow light to
transmit through the teeth, while opaque teeth have higher value.
• There might be inter tooth as well as intra tooth differences in the translucency.
Its extent can vary according to the age of the patient due to the degenerative
and reparative changes in the enamel and dentin.
• To mimic natural teeth the effective use of restorative materials should largely
depend upon this translucent effect.

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Metamerism
• The change in color perception of two objects under different light sources is
called metamerism.
• For example, a shade guide tooth matches the natural tooth under incandescent
light but not under fluorescent light.
• This can be attributed to the difference in the radiant energy of two different
wavelengths of light.
• The standardization of lighting condition during shade matching diminishes the
effect of metamerism.

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Fluorescence
• The emission of light by an object at a different wavelength from that of the
incident light is called fluorescence.
• The emission stops immediately on removal of incident light. Teeth fluoresce
with a stimulus in the range of 340nm to 410nm.
• This spectrum is in the blue range. Thus, according to the principles of additive
color, the emitted blue light acts with the yellowness of the tooth to produce a
whiter tooth.
• Fluorescing pigments incorporated in the ceramic restorations by the ceramist
and in the composite restorations by the manufactures may thus be
advantageously used in altering the perception of the final result.

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Gloss: Gloss is an optical property associated with a smooth surface that
produces lustrous surface appearance and thus reduces the effect of color
differences.
• Increase the brilliance (value 0 of the final result.) In dentistry, unlike spectral
colors, the restorative materials have pigment colors incorporated in them.
The light source: The light source has the color of the emitted light and is
described in color temperature (Kelvin).
• The lighting environment makes significant differences in the perception of
color.
• The teeth and the shade guide should be sufficiently illuminated.

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• The light reflected from a glossy surface obscures the viewer’s perception of
light. Shadows should be eliminated as they reduce the available light and hide
details.
• The dental operatory maybe illuminated by combination of natural sunlight and
artificial light, the artificial light may be incandescent (predominantly) blue.
• Also the ratio between the task light (which falls directly on the working area)
and the ambient light (derived from the surroundings), known as the contrast
ratio, should be higher than 3:1, but lower than 10:1.
• This can be attained by regularly measuring the intensity of light, cleaning the
diffusers and the light sources any by replacing them when their effective life is
over.

Shade selection sequence
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• Any color modification procedures like bleaching or microabrasion should
precede color selection after ensuring color stabilization.
• Make the shade selection at the beginning of the procedure as well as over
different appointments (diagnosis, prophylaxis etc.)and cross check these
observations.
• View the patients at eye-level. The operator should stand between the light
source and the patient.

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• In a contrasting environment, colors look more intense and brighter. Hence it is
wise to ask the patient’s to remove artificial lip color.
• Place the tabs as close as possible to the area that is being checked.
• Moisten the tab and eliminate the worst match.
• Evaluate the value (upper to lower). Value is the most important factor in shade
matching.
• If the value blends, small variation in hue and chroma will not be noticeable.
The value is to be matched with eyes half closed. After value, mark the
translucency.
• Match the chroma (more or less saturated) and finally, hue in that order.

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• To avoid hue sensitivity, rapid observation is made for 5 seconds (not more than
20 seconds). Look away; ideally stare at a blue surface, which will readapt the
vision to the orange yellow portion of the spectrum.
• Match prior to tooth preparation, since preparation dehydrates and changes
color due to the debris of preparation. Match the tab with the opposing tooth
also.
• Metamerism complicates color matching, as the tabs look different under
different light sources. The best approach is to use three light sources; cool
white fluorescent light, incandescent operatory lamp and day light if possible.
• When in doubt, always select higher value and lower chroma, since it is easy to
lower value and increase chroma.

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• Shade tabs of different batches don’t always match; hence it is wise to send the
actual selected shade tab to the technician.
• Make a decision regarding relative translucency, area of hypo calcification,
increase saturation, crack lines surface texture and other characterization. Make
a drawing of the facial surface and record all patient information graphically

Mechanism of bleaching
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• In the presence of moisture as well as surface debris on the tooth, the ionization
by hydrogen peroxide occurs by decomposition into water and nascent oxygen
which is a weak radical making the peroxide inefficient as a bleaching agent.
Hence, it is important to have teeth dry and free of surface debris.
• Increase in the temperature, higher peroxide concentration and the duration of
exposure of the tooth structure to the peroxide within the oxidation process
leading to a greater degree of color change.

Saturation Point
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• Prolonged used of a bleaching agent causes the whitening action to slowdown
beyond a point during the treatment. This is the saturation point.
• The bleaching if allowed to continue, begins to break the inorganic structure
from the enamel rapidly. Bleaching should thus be stopped at or before the
saturation point.
• If bleaching is done beyond the saturation point, it clinically manifests an
increase in porosity on the tooth surface.
• A fluoride application is recommended and no bleaching agents should be
applied allowing the enamel to remineralize.

Procedure for bleaching
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• Use carbamide peroxide solution available in standard 35% concentrations.
• In a technique described as ‘assisted office technique’, 35% carbamide peroxide
is tray loaded for 45 minutes, after following required protocols.
• Some bleaching materials are available in a combination of a hydrogen
peroxide and carbamide peroxide in 20% and 16% concentrations respectively.

Preparation of trays
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• The bleaching procedure is recommended for the number of teeth seen in the
patients active smile. 1 millimeter reservoir for the bleaching gel.
• On the modified cast soft and clear vacuuform matrix of 0.035”thickness is
made. The matrix, carefully trimmed to cover only the clinical crowns.
• Contact of the bleaching gel with marginal gingiva may result in tissue irritation
hence vacuuform trays should have a marginal seal to eliminate contact of the
caustic bleaching gel with the gingiva.

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Isolation of teeth
• Proper isolation of area with cotton rolls or rubber dam is mandatory. The
gingival surface is wiped and dried sufficiently.
Etching of tooth surface
• Each tooth is etched on labial surface for 10 to 20 seconds using 32% - 37%
orthophosphoric acid.
• This step removes any superficial surface stains and enhances the penetration of
the bleaching solution into the tooth surface producing a greater stain reduction.
• Excessive etching causes the demineralization of the enamel matrix, leading to
surface irregularities and causing sensitivity.

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Application of bleaching material
• The bleaching materials is slowly loaded in to the vacuufrom trays so that it
spreads all over the labial surface of the teeth to be bleached.
• The trays are kept in place for an average duration of 30 minutes depending on
the type of material used and the manufactures recommendations.
Micro-finishing and polishing
• Following bleaching, the teeth are micro-finished using fine abrasive disks.
Final polishing is done with aluminum oxide or fine grit diamond.
Office bleaching of non vital teeth
• The two most commonly used agents for bleaching of non-vital teeth are
hydrogen peroxide and sodium perborate.

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Home bleaching
• Bleaching may be carried out at home by the patient. The home bleach
technique involves the application of bleaching agent through the use of
vacuuform trays. The frequently used bleaching agent is 10% - 15% carbamide
peroxide.
Bleaching in relation to bonded restorations
• It was determined in clinical studies that the bond strength of composite to
enamel is reduced when the tooth is bleached.
• The primary cause for the reduced bond strength is the presence of the residual
peroxide or oxygen, which interferes with the polymerization of resin bonding
systems and restorative materials. Any bonded restorations in the bleached teeth
need to be done after a period of two weeks.

78
Enamel microabrasion
• Hydrochloric acid (18%) pumice abrasion can remove white enamel opacifiers,
multicolored defects and many brown, orange, yellow enamel spots and streaks,
regardless of etiology.
• These stains can be eliminated with insignificant enamel loss if the stain is
limited to a thin layer of tooth surface (approx. 0.5mm). This procedure can be
used independently or prior to bleaching to give optimal results.
Management of Fluorosis stained teeth
• A solution of anesthetic ether, hydrochloric acid and hydrogen peroxide may
also be used for bleaching teeth with fluorosis stains.
• The anesthetic ether removes surfaces debris, the hydrochloric acid etches
enamel and hydrogen peroxide bleaches it.

PORCELAIN LAMINATE VENEERS
CLINICAL ASSESSMENT & ANALYSIS
79

80
• Porcelain Laminate Veneer (PLV) is defined as a “thin bonded ceramic
restoration that restores the facial surface and part of the proximal surfaces of
teeth requiring aesthetic restoration.
• The indications of PLV include three types.
• Type I: Teeth resistance to bleaching, as in case of Tetracycline discoloration, and teeth
unresponsive to bleaching procedure.
• Type II: Major morphologic modifications, as in case of conoid teeth (peg shaped laterals),
diastema or interdental triangles to be closed, and augmentation of incisal length or facial
contour.
• Type III: Extensive restorations needed because of extensive loss of enamel by erosion, or
generalized congenital malformations

81
• Contraindications of PLV include several situations. These include
• Teeth exposed to heavy occlusal forces (bruxism),
• Severely malpositioned teeth,
• Presence of soft tissue disease,
• Highly fluoridated teeth,
• Teeth in which color modification can be successfully achieved with various bleaching
techniques, and teeth with extensive existing restorations.
• There are several complications of PLV including postoperative sensitivity,
marginal discoloration, fracture, debonding, and wear of opposing teeth

Factors to Determine PLV Treatment Planning
82
• Preoperative evaluation (Smile Analysis), photography and videotaping are
essential factors to determine PLV treatment planning.
• Tooth position is a factor to be highly considered. The amount of sound tooth
reduction is often related to the position of the teeth.
• In lingually aligned teeth, care must be taken not to reduce unnecessarily the
facial structure of the tooth.
• The soft tissues, gingiva and bone height in relation to adjacent teeth should
always be taken into account to avoid gingival asymmetry and to maintain the
height of the interdental papillae.

83
• Ideally, gingival margins are preferably located on the enamel and away from
the gingiva.
• Over extension of the preparation margins are necessary in these situations:
previous restorations and carious lesions, defective enamel, gingival recession,
root exposure, high lip line and incisal edge position.
• The PLV is not recommended in cases with occlusal problems such as cases
with heavy function (cervical abfraction), parafunctional habits, and
unfavorable occlusal relations.
• Careful analysis to establish correct anterior guidance together with working
and non-working contact is needed. Facebow transfer, centric relation,
mounting on a semi-adjustable articulator, and diagnostic wax-up must be done.

84
• Aged or worn-out teeth exhibit different thicknesses of enamel and surface
texture.
• Enamel may be so thin that any extra preparation may lead to a loss of this
existing precious enamel, which will directly affect bonding.
• The thinner the enamel gets, the more flexible the teeth become. The most
important issue is not the strength of the ceramic material but the preservation
of sufficient enamel and controlling the occlusal forces

Mock up
85
• Mock ups are made for diagnostic reasons during the treatment planning phase
as well as for reference purposes during the treatment phase.
• For the cases requiring major esthetic correction involving many anterior teeth
the dentist can work on the space availability and allotment for every tooth on
the mock up even before proceeding for the tooth preparations.
• A cosmetic preview with the help of composite resins is the easiest and fastest
procedure to help the dentist in diagnosis, treatment planning as well as creating
references during treatment execution.

86
• Composites can be put on the facial tooth surfaces including spaces or even the
gingiva to determine the change of position of teeth desired at the final
restorative phase.
• The dentist can show this preview of the patient and get his opinion regarding
tooth position, shade, shape etc.
• The occlusion usually will restrict the restorative ease in many cases. The
lower incisors should be thoroughly examined and the contacts of the palatal
aspect of the upper teeth marked.
• The functional movements in the mouth can also be checked at this time to
determine any potential occlusion obstructions or difficulties that may arise at
the time of treatment.

87
• Some adjustment in the incisal edges of the mandibular incisors might be
mandatory before proceeding with esthetic correction for the maxillary anterior.
• In cases requiring reduction of tooth structure like in overlapping teeth, a
diagnostic wax-up would be more beneficial as the required reduction of the
teeth can be done on the study casts and suitable colored wax-up can be used to
visualize the end result and preparation design.
• In cases requiring closure of spaces and where crown lengthening could be
required to improve the width to length ratio of the final restorations, a
composite preview could be easily used.

88
• Before crown lengthening procedures the extent of gingivecotomy and the exact
contour to be established on the facial aspect is determined by the location of
the gingival zenith after the placement of the final restoration.
• Hence a composite preview is used to determine the gingival contour and the
gingivecotomy is performed according to this reference.
• Once crown lengthening is achieved and after sufficient healing period elapses,
composite or ceramic veneer is placed to give the final desired result.

89
Considerations in tooth preparations for ceramic laminates
• Tooth preparation design will depend upon the existing color of the teeth,
whether change in alignment or an increase in height of the final restoration is
sought.
• When a mild to moderate discoloration has to be masked the preparation can be
minimal from 0.3mm cervically to 0.5mm at the incisal edge.
• Whenever a severe discoloration has to be masked the preparation has to be
deeper to allow more die spacer to be applied on the model.
• This excessive space allows use of resin curing cement to mask the severe
discoloration. Adding more opaque ceramic in the veneer will mask undesirable
tooth color but will limit the display of vitality.

90
• A more translucent ceramic will allow more light transmission and reflection
internally making the restoration more vital.
• If change in alignment is indicated then more preparation will be required in certain
areas. When length of the veneer has to be increased a palatal extension is
recommended.
Preparation of maxillary teeth for ceramic laminates
• Mock preparation on the pre-operative casts and diagnostic wax up gives valuable
information about the amount of tooth preparation and helps to visualize the end
result.
• Local anesthesia may be required when the preparations reaches the dentin and to
facilitate easy gingival retraction procedures.
• Self-limiting three-tiered depth cutting burs of known dimensions (0.3mm and
0.5mm) facilitate rapid, adequate and conservative tooth reduction.

91
• The depth groves are made by moving them on the facial surface from the
mesial to the distal and by changing the angle of the bur to facilitate their
orientation in two planes.
• Then the facial reduction is achieved following the labial contour of the tooth
till the depth grooves.
• Besides, the contra-lateral tooth can be used as a reference to check adequate
tooth preparation. Selective labial tooth preparation is required to create a
favorable arch form.
• A modified chamfer margin is preferred to allow distinguishable finish line in
the impression, definite seat and adequate bulk for laminates. The margin is
usually supra-gingival or equip-gingival.

92
• The margin is taken intra-crevicularly in certain cases to mask the underlying
discolored tooth and cover cervical lesions.
• The proximal finish line is placed into the embrasure area to ensure that the
margin between the laminate and the unprepared tooth structure is well hidden.
Deficient preparation reveals unaesthetic margins proximally.
• Incisal preparation depends on whether an increase in tooth height is required or
not. In case where the increase is not sought, the incisal preparation ends
midway between the labio-lingual width of the incisal edge.
• In case when the length of incisor is to be increased, the incisal table is flattened
with a bevel of 45 degree palatally.

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• The palatal preparation is a wrap-around design with the margin placed inferior
or superior but never at the contact of the mandibular incisor in centric
occlusion.
• Similarly, window preparations are advocated for canines and premolars when
increase in height in not required.
• When the length has to be increased, the anterior and lateral guidance has to be
considered and appropriate tooth preparations has to be carried out to allow for
adequate thickness of the laminate at the incisal or occlusal area.
Try in
• Chair side try-in is done to check individuals veneer fit, collective fit of veneers
and the shade of the composite luting cement that should be used to get the
desired final result.

94
• Individual veneer is tried for marginal fit, adaptation and retention. Any
premature contacts are relieved at this stage.
• The veneers should fit in passively with good contacts and not actively as it
may lead to displacement of some veneers.
After Cementation
• The patient is viewed periodically for the gingival response and maintenance
regimen. Usually a 3 month check up followed by a 6 monthly check up is
recommended.

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Function and longevity
• A pre-operative analysis of the occlusion is crucial to determine the palatal
extensions and the acceptable length in upper anterior restorations.
• Checking the lateral and protrusive excursions will give an idea as to how far
palatally the final restoration can be placed.
• A conscious effort has to be made to leave at least 2 mm of composite thickness
at the margins for good marginal adaptation and retention in larger restorations.

97
Esthetic predictability
• After elimination of the decay and determining the extent of preparation
required for function and longevity, the preparations are evaluated and if
required redefined.
• The preparation design is extended to allow a smooth transition of shade from
the composite restoration to the rest of the tooth. This enables the restorations
to achieve esthetic excellence.
• To create proper tooth form, shape, shade and texture, and to optimize function,
all cavity preparations designs should have extension for function and esthetics
(EFE).

98
The EFE ensures that the margin of the restoration overlays the defects. The
esthetic advantages are :
• Successful masking of the defect
• Better marginal adaptation
• Natural transition of shade between composite and tooth
• Ease of finishing and texturing
EFE and placement of composite for malaligned teeth
• The preparation in mal aligned teeth is a typical and depends upon the degree of
rotation and angulation exhibited by the teeth and hence a uniform layer of
composite cannot be placed to treat such teeth.
• The effective use of opaque composites in areas having no tooth or thin palatal
structure, improves the blending of the restoration.

99
• Creating surface characteristics and effectively placing the transitional angles
on the facial surface can help to over come deficiency in tooth reduction.
EFE and placement of composite for closing spaces
• Diastema may be manifested to due to microdontia, discrepancy between tooth
size and the available ridge and also due to variation in the tooth morphology.
• Although some natural spaces may be esthetically and phonetically acceptable,
others are not and need corrective restorative procedures.
• However, in cases where the size of the teeth is normal and a diastema still
exists, restorative creations using principles of illusion is recommended.

100
• When a diastema is small up to 2mm, no tooth preparations is required. The
minimal thickness of composite can be adequately shaped especially at the
cervical region to allow good maintenance.
• The preparation design ensures adaptation of sufficient bulk of the composite at
the gingival margin creating contours favorable for gingival health.
• The labial extension allows smooth blending at the composite tooth interface
while the palatal extension provides stability and retention

101
• In cases with diastema larger than 4mm a similar preparation coupled with
recontouring of the other proximal surface of the tooth to maintain tooth
proportions and form may be required.
• Diastemata are filed in one tooth at a time. A celluloid matrix is effectively used
to get the desired contour.
EFE and placement of composites in cervical defects
• Before any preparation, a gingival cord is placed in the sulcus to allow a proper
access to the defect and to keep away sulcular fluid or blood from the cavity
margins.
• A round bur is used to roughen the surface of the cavity and a long bevel is
placed on the occlusal edge of the cavity.

102
• After etching, the cord is changed and bonding adhesive is applied followed by
flowable composite which is used as an intermediate layer.
• The gingival cord is removed after completion of the filling to facilitate
finishing and polishing.
• The occlusion is adjusted, especially eccentric contracts, to take care of primary
or secondary abfractions. Fine diamonds or carbides are used to finish the
margins.

Shade Matching
103
• Shade selection is done following standard protocol with references to the
incisal third, middle third and the cervical third of the tooth.
• The uniqueness of composites permits pilot shade test to reconfirm shade
attributes before final restorations.
• The pilot shade test is carried out using a selected shade in a bulk of 1.5mm-
2mm on the involved tooth and a contra lateral or guide tooth.
• The composite is then cured and finished and the accuracy of the shade match is
confirmed. Any changes in the value, translucency and chroma are recorded
and the shade is changed if required.

104
Three procedural steps for finishing and polishing
• Gross reduction, contouring, defining the margins. Fine grit diamond abrasive
or tungsten carbide finishing bur can be used for the these purposes (100µm
size abrasives)
• Intermediate finishing is used to reduce scratches left by gross reduction and to
blend all surfaces with each another keeping the orientation of various facial
planes intact (less than 100µm but more than 15-20 µm particle size).
• Final abrasive polishing imparts enamel like effect on the restorations. Loose
abrasive devices, disks, pastes with particle size less than 20µm is used.

METAL CERAMIC AND ALL-
CERAMIC RESTORATIONS
105

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Tooth preparations for metal ceramic crowns.
• The incisal edge reduction of 1.5mm – 1.8mm and the occlusal reduction of
1.5mm – 1.7mm with functional bevel is recommended.
• Reduction is achieved by using a wheel diamond on the incisal edge or a round
diamond of known diameter in the occlusal grooves.
• The incisal edge reduction is followed by the labial reduction. When reducing
the labial surface of the tooth, the exact contour must be emulated.
• This helps to prevent excess removal of tooth structure which may lead to
deficient lingual wall preparation especially at the incisal aspect.
• The labial reduction is achieved in two planes with a round-ended tapered bur,
the first orientation involves the incisal two thirds of the tooth.

107
• The palatal reduction is carried out allowing sufficient space for the crown and
to re-establish normal occlusal and protrusive relationships.
• A pear shaped or rugby diamond is used to reduce the lingual concavity while
the rest of the cingulum surface is reduced with a round ended tapered diamond
bur.
• The proximal reduction involves smooth movements from the labial surface to
the palatal allowing its finished margin on the proximal surface. Long tapered
fissures can be initially used followed by round ended fissure burs to achieve
desired reduction.
• Preparations must include 1mm peripheral shoulder or chamfer with bevel for
ceramometal crowns. The objectives are to achieve a convergence angle of the
axial walls in the range of 6 to 10 degrees.

108
• A shoulder with a 90 degrees cavo-surface angle or a stopping shoulder of 120
degrees is recommended for a adequate support of porcelain.
• When the metal margin is shortened for esthetic reasons, shoulder porcelain
requires 1.2mm of tooth reduction at the margin.
• The shoulder with a long bevel is advocated for improved marginal fit but it
cannot be accommodated in shallow gingival sulcus. Hence short bevel of
0.5mm with a cavo-surface angle of 135 degrees is preferred.
• Chamfer (0.5mm) is the finish line of choice for metal backing. For porcelain
fused to metal backing, a metal collar on a modified chamfer is preferred.

109
• The palatal chamfer is blended smoothly with the labial shoulder lingual to the
contact area for good esthetic results. All sharp line angles within the
preparation should be rounded to reduced stress concentration.

110
Try-in
• All metal castings are evaluated for margin integrity, internal fit, stability and
adequate space for ceramic material. Intra occlusal relationship record is needed
in extensive rehabilitation cases.
• Bisque trials for ceramic restorations are assessed for location, site and
tightness of proximal contacts, marginal adaptation and favorable centric and
eccentric occlusal contact without interferences.
• Besides the shape, contours and color; adequate surface characterization is
checked and incorporated.

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Tooth Preparation for all ceramic crowns.
• Although the preparation sequence for all ceramic restorations is similar to the
metal ceramic one, the main concern for the dentist in the preparation for the all
ceramic crowns should be to minimize the stresses that could be incorporated
on the ceramic in function.
• The length of the preparations is important as load applied from a lingual
direction on short preparations can lead to severe compression of the labial
shoulder leading to a fracture.
• The incisal edge is reduced to get flat area however a reduction in excess of
3mm is avoided. In some cases a reduction of up to one third of the crown
height may be required to get rid of the thin incisal edge.

112
• The facial reduction is achieved in two planes at a depth of 1mm to 1.5mm.
• Lingual depth should be 1mm – 1.5mm and should not be less than 0.8 mm.
The proximal preparation is completed with a taper of 6o-8o and will help in
one path insertion.
• Excessive taper will cause inadvertent forces on the ceramic and leads to
reduction in flexural strength.
• The facial reduction, lingual reduction and the proximal reduction should end
into a well defined shoulder.

113
• The shoulder should not create any undercuts for the restorations and hence any
angle in excess of 90 degree should be avoided.
• The shoulder should not necessarily be uniform labially, proximally and
lingually, as excessive reduction may be required to do so, compromising on the
resistance and retention form of the preparation.
• The shoulder is usually 0.8mm – 1.0mm wide in the labial and lingual and
0.5mm – 0.6mm in the proximal aspect where the ceramic flares to give
sufficient strength.
• The smooth finish line should not be steep inter proximally but have a smother
gradient to avoid potential stress area during function.

114
• As compared to the preparation for metal ceramic restorations, the finish line
for all ceramic restorations should be a shoulder which is at right angles to the
direction of stress thus increasing the fracture resistance.
• In the final preparation all sharp line angles and undercuts are avoided
providing maximum strength and resistance.
• Adequate length of the preparation is required in order to counter the tipping
forces and increase the surface area for additional retention.
• The depth of the facial and lingual shoulder should be 1.0 mm (with a minimum
of 0.8 mm) and interproximally the shoulder can be 0.5 mm as the restoration
flares interproximally.

115
• A taper of 5- 10 degrees is advisable for conserving and increased support to the
restoration. Increased taper leads to stress concentration in areas where the
support is lacking.

117
Pre-implant esthetic consideration
• When esthetics is the prime reason for seeking implant prosthetic treatment, the
patient’s upper lip line will be of extreme importance for the planning of the
definitive superstructure.
• In patients with a high lip line or requiring upper lip support from the prosthesis
a removable over denture will more likely fulfill the demands of function and
esthetics than an implant borne bridge construction.
• The dentist should analyze anterior single tooth implant situations considering
the adjacent teeth, contra-lateral tooth, probable emergence profile and presence
or absence of inter dental papilla when ever the active smile exposes enough of
gingival tissues.

118
• Majority of the cases of maxillary single tooth implant in patients with high
upper lip line require bone grafting for ideal esthetics while in some cases bone
grafting would be necessary to provide adequate healthy peri-implant soft tissue
to maintain optimal hygiene in the cervical region.
• Apart from the inadvertent deficiencies in the facial bone associated with
various clinical situations, the soft tissue form also plays a major role in the
esthetic outcome of single tooth implants.
• In 1989, Misch reported 5 prosthetic options available in implant dentistry. The
first three options are fixed prosthesis (FP).

Prosthodontic classification
119
• FP – 1 Fixed Prostheses, replaces only the crown, looks like a natural tooth.
• FP – 2 Fixed Prostheses, replaces the crown and a portion of the root; crown contour
appears normal in the occlusal half but is elongated or hyper contoured in the gingival
half.
• FP – 3 Fixed Prostheses; replaces missing crowns and gingival color and portion of
the edentulous site; prostheses. Most often uses denture teeth and acrylic gingiva, but
may be porcelain to metal.
• RP – 4 Removable prostheses; over denture supported completely by implant.
• RP – 5 Removable Prostheses; over denture supported by both soft tissue and implant.

Fixed Prostheses
120
• FP-1 is a fixed restoration and appears to the patient to replace only the
anatomic crowns of the missing natural teeth. There usually has been minimal
loss of hard and soft tissues. The final restorations appears very similar in size
and contour to most traditional fixed prostheses used to restore or replace
natural crowns of teeth.
• FP –1 prosthesis is most often desired in the maxillary anterior region.
However the width and / or the height of the crestal bone is frequently lacking,
augmentation is often required before implant placement to achieve a natural
looking crown in the cervical region because there are no inter dental papillae in
edentulous ridges, gingivoplasty is required after the abutment is positioned to
improve the interproximal gingival contours.

121
• FP-2 fixed prosthesis restores the anatomic crown and a portion of the root of
the natural tooth. The volume and topography of the available bone dictate a
deficient vertical implant placement compared with the FP-1 prosthesis, which
is more apical compared with the cemento-enamel function of a natural root.
• As a result the incisal edge is in the correct position, but the gingival third of the
crown is over extended, usually apical and lingual to the position of the original
tooth.

122
• The FP-3 is a fixed restoration that appears to replace the natural teeth crowns
and a portion of the soft tissue. As with the FP-2 prosthesis, the original
available bone height loss decreased by natural resorption or osteoplasty at the
time of implant placement.
• To place the incisal edge of the teeth in proper position for esthetics, function,
lip support and speech, the excessive vertical dimension to be restored required
teeth that are unnatural in length.
• The patient having high maxillary lip line during smiling and low mandibular
lip during speech will display the longer teeth which look unnatural.

123
• RP-4: It is a removable prosthesis completely supported by implants and or
teeth. It may draw the same appearance as an FP-1, FP-2, FP-3 restorations.
• RP –5: It is a removable prosthesis combining implant and soft tissue support.
The prosthesis is very similar to traditional over denture.

Factors for favorable implant placement
124
The physiologic limits within which the implant can be placed are governed
by the following:
• The space between implant and periodontal ligament of the adjacent tooth
should be 1mm.
• The average width of periodontal ligament is 0.25mm.
• These natural periodontal components will require a space of 1.25mm on either
side of the implant. Thus, mesio-distally the implant diameter is added to this
minimum space required.

125
• The facio-lingual requirement: For a 3.5mm implant placed in the anterior
region a minimum of 6mm of space mesio-distally has to exits to accommodate
all related components.
• Ideally, the ridge should be 5-6mm wide labio lingually, to allow at least 1 mm
of the cortical bone labially and lingually. However, to impart esthetics in the
inter dental papilla region, the distance between an implant and natural teeth is
kept 2mm.
• The implant should be 3mm apical to the gingival margins of the adjacent teeth.
• Labio-lingual orientation of the implants helps to achieve desired emergences
profile. Placing the implant slightly palatally helps the dentist to build up a
proper emergence profile to the crown.

126
• To obtain satisfactory peri-implant gingival morphology, tissue volume should
be 20-25% more than the estimated need to allow adaptation of gingiva to the
prosthetic reconstruction.
• Wider diameter implant will ease the transition of the implant head to the
artificial crown as it emerges from its soft tissue housing.
• The wider diameter implants will not be required to be placed far apical to the
cemento-enamel junction of the adjacent tooth.
• Immediate implants help to preserve the hard and soft tissues, and maintain the
emergence profile as in natural teeth.

128
Esthetic Periodontal Considerations
Shape and position of the gingiva:
• In an ideal esthetic relationship, the position of the gingival margin is dictated
by the vertical limits of the active smile, the gingival margins of the maxillary
central incisors and canines positioned at the vermilion border of the upper lip.
• The gingival margin of the lateral incisors is usually located 1 to 2 mm more
incisally or at the same height of the central incisors and canines.
• The gingival zenith is distal to the long axis of the tooth for both the maxillary
central incisor and canine while it is situated on the long axis of the tooth for
the maxillary lateral incisors.

129
• The gingival height of contour of the premolars and molars lies in a more
occlusal position as it moves posteriorly.
• The horizontal limits as well as the vertical limits of the smile should be
evaluated. Most patients show the maxillary teeth with or without the gingiva
upto the first molar in an active smile.
• To provide for proper depth and harmony of the smile, the gingival display
should be consistent and proportional from tooth to tooth, from the left first
molar to the right first molar.

130
Embrasures
• In healthy periodontium the inter dental papilla blends into embrasure spaces
completely from buccal to lingual which is an important esthetic factor assuring
harmony in the dental composition.
• However, in cases of recession or post-periodontal therapy the embrasures may
open up revealing a black triangle.

131
Biologic width
• It has been demonstrated from autopsy recordings that the mean sulcus depth is
0.69mm, mean length of the junctional epithelium is 0.97mm and connective
attachment is 1.07mm; the combined width of the latter two is 2.04 mm and is
called the ‘biologic width’.
• This biologic width is always present, therefore restorative margins must
maintain a distance from the alveolar crest that respects the biologic width,
otherwise gingival recession or pocket formation ensues.

Esthetic periodontal defects and its correction
132
Periodontal defects posing an esthetic problem may include:
• Violations of biologic width
• Gingival asymmetries
• Excessively gingival display
• Localized gingival recessions
• Deficient pontic areas
• Abnormal frena.
• Excessive gingival pigmentation
• Inadequate interproximal papilla
• Restorations which are over extended in the cervical region should be carefully
removed and proper cleaning of the teeth is recommended with excavation of
deep carious lesions in the cervical region.

133
• Provisional restorations should then be fabricated with proper contouring in the
cervical region. The pockets should be probed and isolated areas of excessive
bone loss should be marked and regenerative procedures instituted.
• Surgical technique for establishing proper biologic width involves recontouring
the osseous crest so that a minimum of 3 mm of the flap can be placed coronal
to the position of the recontoured osseous crest. This will take into
consideration the average biologic width of 2mm.
• In accidental tooth fractures or any other clinical situations where the
restorative margins may violate the biologic width, bone removal in the
adjacent teeth might be necessary to get desired esthetic result.

134
Gingival asymmetries
• Whenever the facial gingiva of the anterior teeth does not follow a symmetrical
pattern, crown length discrepancies are perceived; some teeth appear longer
while others appear shorter. Correcting these discrepancies to an esthetic
gingival pattern becomes the main goal of the esthetic or restorative dentist.
• The possible causes of gingival asymmetries are :
• Gingival hyperplasia
• Altered passive eruption
• Tooth or teeth malpositioning
• Over zealous tooth brushing
• Periodontal disease

135
Esthetic crown lengthening
• When a disparity in the clinical crown length exits between contra lateral teeth
resulting in a left/right side height discrepancy, esthetic surgical correction can
be provided to enhance the cosmetic result before restorative measures.
• In such cases ‘esthetic crown lengthening’ may be carried out by performing
gingivectomy and or osseous resection only on the facial aspect, for better
esthetics. Root exposure is often a common complications and intentional root
canal or post surgical treatment with veneers or crowns may be required.

136
Excessive gingival display (gummy smile)
• A gingival display of more than 3mm in active or moderate smile may be
termed “gummy”. Excessive gingival display or gummy smile can be caused
by any of three factors.
The causes include:
• Maxillary over growth
• Tooth malposition
• Delayed apical migration of the gingival margin or altered passive eruption.
• Crown lengthening procedures can correct the latter two defects. Usually a
surgical and orthodontic correction may be needed in these cases.

137
Deficiencies in edentulous ridges
• Several surgical techniques have been devised to restore the contour of
edentulous ridges that have been altered by disease or trauma before adaptation
of pontics. The most commonly used classification is as follows:
• Class I: Bucco-lingual loss of tissue with normal ridge height in an apico-
coronal direction.
• Class II: Apico-coronal loss of tissue with normal ridge width in a bucco-
lingual direction.
• Class III: Combination of bucco-lingual and apico-coronal loss of tissue
resulting in a loss of normal ridge height and width.

138
Correction of class I type of defects
• Bucco-lingually edentulous ridge defects are the most commonly encountered
and most predictably treated of all alveolar ridge defects.
• Surgical procedures such as inter positional grafts of hydroxyapatite or
connective tissue are ideal for augmentation for such type of defects.
• For connective tissue grafting, the donor site selected is usually the one with the
thickest available connective tissue, such as maxillary tuberosity.
• Augmenting the edentulous ridge at the time of surgery slightly more than
necessary will compensate for the shrinkage that occurs during surgical healing.

139
Correction of class II defects
• These are more difficult to treat predictably and are usually corrected with
onlay grafts. Slight defects in any plane of space can be treated. Usually in one
stage while moderate to severe type of defects often require multiple procedures
with an interval of 6 to 8 weeks post operatively.
Correction of class III defects
• This is the most difficult type of defect to manage and generally requires
multiple surgical procedures. Palatal donor sites fill in totally within 4-8 weeks
and can again serve as donor sites, if necessary.
• When multiple procedures are anticipated the bucco-lingual dimension is
generally recaptured first, this sequence provides a broader base (more
vascularity) for the on lay graft.
•

140
Abnormal frenal treatment
• For diastema closure. A resection (frenectomy) or a repositioning (frenotomy)
may be necessary.
• Whenever there is excessive pressure caused by the frenum, then a frenectomy
may be the best procedure, however when esthetics is the only factor then a
frenotomy may be necessary to give the desired result.

141
Excessive gingival pigmentation
• Skin tone, texture and color differ in races, and different regions the color of the
human gingiva also differs, usually pink with certain areas showing a diffuse
pigmentation.
• Gingival pigmentation is due to the deposition of melanin pigments in the basal
layer of the mucosa. In mammals it is brown, black or blue black.
• The saturation of these pigments causes an unaesthetic dark or gingival display.
In people with fair skin and high lip lines. The pigmentation usually occurs in
diffuse patches; some times a continuous area is seen.

142
The surgery can be performed under local anesthesia with the following
techniques.
• Gingivo-abrasion technique
• Split thickness epithelial excision
• Combination technique which involves gingivo-abrasion and split thickness
epithelial excision.
Gingivo-abrasion technique
• A medium grit foot ball shaped diamond bur is used at high speeds on the
epithelium to denude it. Care should be taken not to abrade the periosteum.
• A periodontal pack is the placed over the denuded epithelium.

143
Split thickness epithelial excision technique
• A split thickness island of epithelium is removed on the attached part of the
mucosa.
• A periodontal pack is then placed and left for a week.
Combination technique
• In cases where pigments are present very close to the marginal gingiva and
where the gingival pattern as areas of depression and elevations on the facial
aspect, a combination technique is advised. Gingivo-abrasion is used near the
marginal gingiva and areas where a split excision of difficult.

144
Open inter proximal spaces
• The inter dental gingival occupies the gingival embrasure which is the inter
proximal space beneath the area of tooth contact. The shape of the gingival in
a given inter dental space depends on the contact point between the two
adjacent teeth and the presence or absence of some degree of recession.
• Open inter-proximal space may be caused due to diverging roots, abnormal
clinical crown shape and absence of inter proximal papilla.
• The first two can be corrected orthodontically and by the reshaping of the
clinical crown respectively. While the last is the most difficult to manage.
Because currently there are no predictable methods to regenerate the inter
proximal papilla.
•

146
Crown width discrepancy
• Tooth size discrepancy is commonly found in patients with peg shaped lateral
incisors.
• Even after getting the teeth perfectly aligned and the arch forms properly
established with orthodontic treatment, the abnormal shape and smaller size of
lateral incisor poses an esthetic problem.
• To determine the space required to restore the crown width, during the
treatment planning stage, construction of a diagnostic wax up in an important
step to visualize the final result.

147
• After removal of the fixed orthodontic appliances, restorative phase should be
immediately started and provisional restorations should be given before final
restorations to avoid relapse. Maxillary peg-shaped lateral incisors can be
restored with ceramic veneers.
Proximal re-contouring
• When the widths of the anterior teeth do not follow the golden proportions.
Then the larger teeth should be re-contoured to smaller size and the space thus
created is effectively utilized by the orthodontist to resolve the discrepancy.
This procedure is usually done before starting orthodontic treatment and care
should be taken not to alter the morphology of the teeth and the contact points.

148
Space gaining for a single tooth restorations
• Loss of a tooth in the posterior segment can led to tipping and drifting of
adjacent teeth. In case of loss of the maxillary right second premolar leads to
medial tipping and mesio-palatal rotation of the first molar.
• This results in reduction in the pontic space. Large Nance palatal button can be
cemented for palatal anchorage to move the molar distally.
• The maxillary first molar can be moved distally creating sufficient space for the
pontic. After provisional restorations the final restorations can be placed.

149
Replacement of missing laterals with implants
• The osseo-integrated implant is the most conservative and biological method,
since the missing tooth can be replaced without damaging neighboring teeth.
• If the use of implants is the part of treatment plan for the missing lateral
incisors, it is necessary to decide the exact placement of implants, evaluate the
smile line and gingival contour.
• When the lateral incisors are missing, there is usually no adequate space to
restore them due to drifting of the adjacent teeth. In such cases, it is essentially
to gain adequate space with orthodontic for the placement of implant and crown
restoration for good esthetic result..

150
• The exact amount of space created should be according to the proposed size of
lateral incisors, which should be proportions to the width of the central incisors.
• Before the orthodontic appliances are removed it is important to evaluate
radiographically the position of the roots of adjacent teeth.
• The minimum space of 6.5mm between adjacent roots is required to place a
standard implant of 3mmm width.

151
Impaired dento-facial esthetics and function due to absence of canines.
• The position of canines in all three planes of space is very important from
esthetic and functional point of view. The ectopic eruption and impaction of
maxillary permanent canines is a frequently encountered clinical problem.
• The canines also provide the main gliding inclines for lateral excursions of the
mandible. Thereby providing the patient with a functional occlusion.
• Therefore, it is not only important to get healthy favorably positioned impacted
teeth into occlusion but also to position them in such a way that they maintain
the integrity of occlusion, provide good function and optimal esthetics.

152
Establishing proper anterior guidance
• As Angle (1907) stated that, “Each dental arch describes a graceful curve and
that the teeth in these arches are so arranged as to be in greatest harmony with
their fellows in the same arch, as well as those in the opposite arch. The sizes,
forms, inter-digitating surfaces, and positions of teeth in the arches are such as
to give one another, singly and collectively, the greatest possible support in all
directions”.
• Proper inter-incisal relationship is important to maintain the vertical position of
incisors. Loss of this relationship leads to supra-eruption of incisors and deep
bite.
• In severe deep bite case, there is often attrition of lower incisal edges and the
palatal surfaces of upper incisors, leading to shorter clinical crowns of the lower
incisors and lack of anterior guidance

153
• In such a clinical situation, if there is any restoration in the maxillary anterior
region, it will have a tendency to de-bond due to lack of sufficient vertical
clearance.
• Therefore, it is necessary to establish proper anterior guidance with
orthodontics so that the palatal surfaces of upper anterior could provide a
harmonious glide path for the lower anterior teeth during the protrusive
excursion of the mandible.
• These teeth should work against one another to separate or disclude the
posterior segments as soon as the mandible moves out of centric closure.

RECENT ADVANCES IN SMILE DESIGN
IN PROSTHODONTICS
154

155
• Digital Smile Design (DSD) is a worldwide recognized scientific concept that
has been used for over a decade now by top dental technicians and dentists from
all over the world, that improve the quality of aesthetic dental treatments.
• Digital Smile Design (DSD) is a multipurpose digital tool with clinically
relevant advantages. It can strengthen esthetic diagnostic abilities, improve
communication among team members, create predictable systems throughout
the treatment phases, enhance patients’ education and motivation through
visualization, and increase the effectiveness of case presentation.

DSD Software Capabilities
156
• With the help of digital facebow, DSD allows a careful esthetic analysis of the
patient’s facial and dental features and discovery of many critical factors that
might have been overlooked during the clinical, photographic, or study model
evaluation.
• Drawing reference lines and shapes over extra- and intraoral digital
photographs in presentation software, following a predetermined sequence,
helps widen the diagnostic vision.
• The digital ruler helps in measuring the gingival and incisal discrepancies for
treatment planning and for guiding the wax-up.

157
• Virtual Articulator and occlusal analysis helps detecting occlusion and
mesiodistal or buccolingual space discrepancies. DSD drawings aid in better
understanding the space management possibilities, implant position, and
horizontal ridge reconstruction .
• Seven DSD Systems are available in the market currently namely
• CEREC Smile Design (SIRONA),
• Digital Smile Design (DSD),
• Digital Smile System (DSS),
• G Design (HACK DENTAL),
• Romexis Smile Design (PLANMECA),
• Smile Composer (3 SHAPE) and
• Smile Design Pro (TASTY TECH).

Current concepts of smile design attributes
158
Recent advances in digital photography:
• Extraoral Video Camera takes photograph of patient while moving or talking so
that various moods and gestures can be captured and give details, which even
the patient, is unaware.
• Latest Intraoral camera is the revolutionary “patient conversation starter.” The
camera’s unique liquid lens technology works like the human eye to ensure
effortless image capture to deliver clear, detailed images patients can really
understand.
• The Duo Cam is a Dental Camera Technology Breakthrough as it takes both the
highest resolution Intraoral images and also takes Extraoral pictures for your
Cosmetic, Dental examinations and Patient Communication needs.

159
Recent advances in shade selection:
• Colorimeter, spectrophotometer, spectroradiometer and digital cameras have
changed the way a shade selection used to be done. All these devices have made
subjective color analysis to objective color analysis and with no influence of the
external environment.
• Colorimeter is the instrument that combines digital color analysis with
colorimetric analysis. It consists of a hand-held device with its own light
source, and an LCD screen facilitates positioning on the tooth.
• Spectrophotometer is the only one that combines digital color imaging with
spectrophotometric analysis.

160
• Hand-held spectro-photometer consists of a hand piece connected to a base unit
by a monocoil fiber optic cable assembly.
• The contact probe tip is approximately 5 mm in diameter. The tooth is
illuminated by the periphery of the tip, directing the light from a halogen bulb
in the base unit into the tooth surface.
• The display presents the closest Vita shade in the classical or 3D shade guide
designation.
• Digital cameras capture images using CCDs, which contain many thousands or
even millions of microscopically small light-sensitive elements (photosites).
Like the photodiodes, each photosite responds only to the total light intensity
that strikes its surface.

161
Recent advances in intraoral scanners
• The introduction of three-dimensional intraoral scanners has changed the face
of traditional dental laboratory dependent dental clinics. It's a total plaster or
stone free dentistry now. All the disadvantages associated with plaster models
are alleviated. Latest intraoral 3D scanners are listed below:

Recent advances in esthetic materials and techniques
162
• Prefabricated Composite Veneers: From the mid-1970s, the prefabricated
composite veneer option was however soon abandoned due to former
technological limitations. Recently, the creation of a new shade guide
comprising enamel shells revitalized this “old idea,” and in combination with a
high pressure and temperature molding process followed by a laser surface
vitrification, a novel, improved composite prefabricated system is introduced.
• Indirect Composite Veneers: Initially the composite veneers were fabricated
in the dental laboratory using light cure unit and now with the availability of
CADCAM composite blocks have made possible the indirect fabrication using
CADCAM.

163
• Direct Composites: Nanofillers, Ormocers, Giomers and Silorane have
improved the mechanical as well as esthetic properties of direct composite resin
thereby enchanicing its usage for smile design purposes.
• Preparation Designs: Tooth preparation through Aesthetic Previsualization
Temporaries (APT) using depth cutter burs at 3 different angulations to achieve
accurate depth ensures a more minimally invasive technique for laminate
preparation. Lumineers a special brand of laminates were introduced lately,
which requires little or no preparation (preparation as thin as contact lens).

164
Recent advances in ceramics
• Dental Ceramics have come a long way from YTZP Zirconia ceramics to
CADCAM, which ensured its usage for three unit bridges too. CEREC 1,
CEREC 2, CELAY, CEREC 3 and now CEREC 3D System is introduced. The
subtractive milling has reached till the level of five-axis milling. Introduction of
additive milling have reduced the disadvantages associated with subtractive
milling like the material loss.
Smile design with dental implants
• Esthetic means of ensuring smile design in implants are gingival contouring,
ridge augmentation, various provisionals, customized abutments and gingival
formers with the biggest breakthrough being Zirconia abutment.

165
Bleaching and abrasive techniques
• With the advent of photo assisted bleaching with Lasers and LED especially
Argon laser of 488nm KTP or 532 nm, bleaching is now become
photochemical. Blue LED 472nm is used. Titanium oxide nanoparticle based
catalyst is used so Hydrogen peroxide is reduced so there is less sensitivity.
There are various means of bleaching like whitening strips, paste, gels and
rinses etc.

166
Bonding and cementation
• We have reached a Seventh Generation bonding era, which is single component
one step self etch, adhesive.
• A Universal Adhesive for both the tooth & ceramic is also introduced. Color
change after cementation should also be taken into account while cementing.
• Panavia is best as it contains MDP for bond. When we are working with
laminates light cure is best as dual cure resin may not give enough workability.

Omar D, Duarte C. The application of parameters for comprehensive smile esthetics by digital
smile design programs: A review of literature. The Saudi dental journal. 2018;30(1):7-12.
168
• Compared DSD programs commonly used in cosmetic dentistry and their
ability to assess esthetic parameters.
• A literature review was performed of current dentofacial aesthetic parameters
and clinical applications of computer technology to assess facial, dentogingival
and dental esthetics.
• Eight DSD programs (Photoshop CS6, Keynote, Planmeca Romexis Smile
Design, Cerec SW 4.2, Aesthetic Digital Smile Design, Smile Designer Pro,
DSD App and VisagiSMile) were compared.
• Photoshop, Keynote and Aesthetic Digital Smile Design included the largest
number of esthetic analysis parameters.

169
• Other studied DSD programs presented deficiencies in their ability to analyze
facial esthetic parameters but included comprehensive dentogingival and dental
esthetic functions.
• The DSD App, Planmeca Romexis Smile Design, and Cerec SW 4.2 were able
to perform 3D analysis; furthermore, Cerec SW 4.2 and PRSD could be used
jointly with CAD/CAM.
• It can be concluded that despite the fact that they were not specifically designed
for dental diagnosis, Photoshop CS6 and Keynote provide a more
comprehensive smile analysis than most specialized DSD programs.

Meereis CT, De Souza GB, Albino LG, Ogliari FA, Piva E, Lima GS. Digital smile design
for computer-assisted esthetic rehabilitation: two-year follow-up. Operative dentistry.
2019;41(1):13-22.
170
• Did a two-year follow-up for an esthetic rehabilitation clinical case in which the
method of digital smile design (DSD) was used to assist and improve diagnosis,
communication, and predictability of treatment through an esthetic analysis of
the assembly: face, smile, periodontal tissue, and teeth.
• The smile’s esthetics were improved through gingival recontouring, dental
home bleaching, and a restorative procedure with thin porcelain laminate
veneers using lithium disilicate glass-ceramic (e.max Ceram, Ivoclar-Vivadent)
laminates.

171
• It was concluded that the treatment using gingivoplasty, tooth whitening, and
thin ceramic laminate veneers, when done using appropriate materials and
techniques, is a minimally invasive approach and is a feasible option for
esthetic rehabilitation, showing satisfactory clinical applicability and
contributing to the aesthetic result over two-year follow-up.

Alrizqi AM, Mohammed YH, Albounni R. Smile design: assessment and concept. Int J of
Cur Res. 2015;7:24746-50.
172
• The aim of the study is to highlight traditionally accepted smile design concept
with additional newer parameters incorporated in the esthetic treatment of the
patients.
• Literature search was carried out by using various search engines (Pubmed,
Google scholar, EBESCO) and articles reporting general facial analysis, dento-
facial analysis, dento-labial analysis, dentogingival analysis and dental
analysis were appraised.
• It was concluded that Smile design is an individualized concept requiring
consideration of many parameters. Therefore, careful diagnosis analysis of
various hard and soft tissue parameters should be part in the treatment of smile
design while keeping in mind the esthetics and function. Multi- disciplinary
approach towards smile design in consultation with different dental specialties
can aid in better designing of smile and facial esthetics.

174
• Dentistry is an ever changing science. As new research and clinical experience
broaden our knowledge, changes in treatment are required.
• This paradigm shift in the field of dentistry comes along just in time to meet the
final needs and wants of patient who perceives an attractive smile no longer as a
luxury but rather a necessary part of their life style.
• Aesthetic dentistry enables the dentist to change the appearance, size, color,
shape, spacing and positioning of the teeth.
• The allure of conservative preparations, the potential for excellent esthetic
results and gingival health has made this branch of dentistry very popular over
the world. No wonder it has enjoyed such a wide spread utilization and at the
same time proven itself with such predictable and excellent results.

175
• Dr. Charles Pincus is rightly recognized as the Father of esthetic dentistry made
a prophetic statement in the year 1937 which is quoted as “A captivating smile
showing an even row of gleaming white natural teeth is a major factor in
achieving the dominant characteristic known as personality.”
• This entails a lack of inferiority complex which causes a hand to be raised to
cover the mouth.
• It is this lack of confidence in the dental equipment, which often spells the
difference between success and failure in the life of many people.
• The above statement was true in the year 1937 is a reality today and will be so
in the years to come.

177
• Solomon EGR: Esthetic consideration of smile; J of IPS 1999: 10(3); 41-47
• Goldstein, RE: Change your Smile, ed 3 Chicago, Quintessence, 1997.
• Morley, J : The role of cosmetic dentistry in restoring a youthful smile: JADA
1999; 1166-1172.
• Sohomura T et al : Use of an ultra high speed laser scanner for costructing three
dimensional shape and occlusion: JPD 2000; 84(3): 345-352
• Kamal Shigli, Swaraj Bharati: Role of technology in designing a confident
smile. J. IPS Dec. 2001, vol.1, no.4.6)
• Friedman, MJ and Hodcman, M.N.: P-ASA Block injection: Anew palatal
technique to anaesthetize maxillary anterior teeth: J of esthetic dentistry, 1999;
11(2): 63-77.

178
• Singer BA. Principles of esthetics. Curr Opin Cosmet Dent 1994;:6-1
• Messing MG. Smile architecture: beyond smile design. Dent Today 1995
May;14(5):74, 76-9
• Dorfman WM. How to design smile styles for cosmetic dentistry. Dent Today
1995 Oct;14(10):68-9
• Morley J, Eubank J. Macroesthetic elements of smile design.
• Meereis CT, De Souza GB, Albino LG, Ogliari FA, Piva E, Lima GS. Digital
smile design for computer-assisted esthetic rehabilitation: two-year follow-up.
Operative dentistry. 2016 Jan;41(1):E13-22.
• Alrizqi AM, Mohammed YH, Albounni R. Smile design: assessment and
concept. Int J of Cur Res. 2015;7:24746-50.

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