The document discusses artificial and temporary crowns. It defines an artificial crown as a fixed prosthesis that restores the anatomical shape, size, and function of a damaged tooth. Temporary crowns are made directly by the dentist or indirectly by a dental technician from an impression. They serve to protect the prepared tooth, maintain esthetics and function during treatment, and ensure proper fit of the eventual permanent crown. The document outlines methods of tooth preparation, materials used for temporary and permanent crowns, and the functions of temporary crowns.
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Artificial crowns. Temporary crowns..pdf
1. *«Artificial crown
Temporary crown»
ФГБОУ ВО «Кабардино-Балкарский государственный университет
им. Х. М. Бербекова»
Институт стоматологии и челюстно – лицевой хирургии
Составитель: Карданова Светлана Юрьевна.
Мамхегова Карина Хусеновна.
Картинки/рисунки для данной презентации взяты из
материалов, находящиеся в сети в свободном доступе.
2. is a fixed prosthesis that covers the clinical
crown of the tooth and
restores its anatomical shape, size and
function.
3. INDICATIONS FOR ARTIFICIAL CROWN
To restore the anatomical shape of the tooth, damaged as a result of carious
and non‐carious lesions;
To restore the color, shape and position of the tooth;
For fixing removable dentures (with clasps, when it is necessary to improve
the shape of the abutment tooth);
For splinting mobile teeth with periodontitis and periodontal disease;
With pathological abrasion to restore the height of the bite and prevent
further erasure;
Used for fixing bridges as supporting elements;
For temporary fixation of orthopedic, orthodontic and maxillofacial
appliances;
In case of deformation of the dentition, when we need to make
correction of the shape by covering displaced teeth with crown. (convergence -
inclination of the teeth towards the defect; divergence ‐ inclination of the teeth in the
opposite direction from the defect, the Popov‐Godon phenomenon)
4. МЕТОДЫ ОПРЕДЕЛЕНИЯ СТЕПЕНИ РАЗРУШЕНИЯ ЗУБОВ
Визуальный Определение ИРОПЗ
До 1/3 пломбирование
½ - 2/3 вкладки
Более 2/3 искусственные
коронки
0,2 – 0,6 пломбы,
вкладки
0,6 – 0,8 искусственные
коронки
Более 0,8 штифтовые
конструкции
8. Types of pin structure:
a - a pin tooth by Ilina - Marcosian;
б - a typical chiffon tooth made of plastic;
в - a pin tooth as a support for a cantilever prosthesis;
г - a pin tooth by Richmond;
д - a pin tooth as support for bridge-shaped prosthesis.
32. *
One of the tasks of
odontopreparation is:
- to give the tooth crown a
retentive, resistant form, which
would make it possible to hold
the orthopedic dental structure
on the stump;
- create the necessary space for a
fixed denture;
- create a correct (vertical, unidire
ctional) the path of insertion
33. Macro‐retention
The main indicators of macroretention are:
• The total occlusal convergence angle of the walls of the stump
(that is, the preparing tooth stump) is the angle of convergence
between two opposite lateral surfaces (that is, the proximal
contact surfaces to each other and the vestibular and oral
surfaces to each other),
• Stump height
• Preservation of anatomical structures (fissures, cusps)
34. *
Convergence of walls
(inclination of walls to each
other) = +/‐ 6‐7 degrees.
Strong convergence of the
walls = weakening of
fixation, de‐cementing. .
No taper = obstruction of
the path of insertion, stress
in the material of
construction.
The creation of a weakly conical stump is necessary for unhindered
placement of the prosthesis, as well as to eliminate stress in one‐piece frame
and ceramic veneer
35.
36. An over‐trimmed stump (a highly converged stump is bad !!!) has many
paths along which the pulling force can remove the structure.
To assess the taper of the stump of a tooth, it is recommended to look at it with
one eye from a distance of 30 cm. In this case, you can see all the axial walls of
the stump in the same time, adequately assess the taper up to 6 degrees. With
binocular perception, a stump with undercuts can be evaluated as a tooth with
an acceptable taper. Binocular vision should not be used to assess the taper of
the prepared tooth stump!
38. Preparation in two inclination theory was developed and detailed by Kuwata
According to his theory, the vestibular surface of all teeth and the palatal (lingual) surface of
molars and premolars have 3 inclination:
• cervical (which corresponds to the direction of the root plane),
• the main one (which coincides with the plane of the gums of the alveolar process)
• the incisal edge (for incisors and canines) or cusp (for premolars and molars)
39. During preparation for an artificial crown, 2 inclination must be
taken into account: the main and incisal edges.
The cervical plane will be important when creating the crown,
ideally the contour of the crown in the marginal area should
match the cervical plane
Over‐contouring the crown will lead to chronic gingival in
flammation.
Three‐plane preparation is performed when processing the
vestibular surface of the tooth under the veneer ‐ the path of
insertion is horizontal and undercuts are not terrible.
40.
41.
42. The path of insertion has been defined as the direction of movement of an
appliance or prosthesis from the point of initial contact of its rigid parts with
the supporting teeth to the place of final rest
In this case, the process of placing an artificial crown on a stump (preparing
tooth).
Artificial crown
Tab
VERTICAl path of insertion AC.
43. More rounded transition lines between the
walls will help reduce stress in the dental
prosthetics and make a tighter fit.
Due to sharp corners in ceramics, stress can
lead to chipping, breakage. And for a milling
machine, it is difficult or almost impossible to
adequately grind structures from zirconium
dioxide
The preservation of the palatine / lingual
tubercle on the stump is an important
factor in the macroretention of the
anterior teeth, because this reduces the
angle of convergence and preserves the
"retention area" of the prepared tooth.
The palatal / lingual tubercle allows
maintaining the minimum angle of
convergence in the vestibular‐palatal
direction, the two‐plane preparation of
the tooth creates a visual sensation of
undercut on the vestibular surface, in
fact, there is no undercut.
45. *Horizontal preparation
Preparation of the stump using horizontal finishing lines (shoulder and chamfer).
Advantages:
• Avoiding overhanging edges of the restoration
• Respect for biological width, that is, less invasive
• Simplification of the process of communication between the doctor and the
laboratory, since it is easier for the dental technician to convey the preparation
boundary.
• During fitting and fixation, it is better to control the marginal fit of the tooth
and AC, veneer.
• Isolation ability, adhesive fixation
46. *Horizontal preparation
In the foreign literature on teeth dissection for crowns, three main types of ledge
are described:
Shoulder – It can be positioned at an angle of 90, 110-120 and 135 degrees
with respect to the side wall of the cult. An angle of 135 degrees requires the
creation of a circular metal garland.
Chamfer – This kind of finish line has a shape corresponding to half of the
groove, some authors call it a rounded ledge.
Beveled shoulder – Requires the creation of a circular metal garland. It is
commonly used in low clinical dental crowns to create additional retantion.
56. Finish line can be:
Subgingival (subgingival) ‐ а;
At the level of the gingival margin ‐ б
Supragingival (supragingival) – в
Gum
Finish line
57. Location of the preparation margin in relation to
the gingival margin:
58.
59.
60. *
The biologic width is the distance established from the junctional epithelium and
connective tissue attachment to the root surface of a tooth. This is also described as
the height between the deepest point of the gingival sulcus and the alveolar bone
crest.
Histologically, it includes connective tissue (Sharpey fibers) and
junctional epithelium attached to the tooth.
In some cases the gingival sulcus with free epithelium include in the biological width
and called the "biological zone".
Biological width medium size: attached connective tissue 1.07 mm + attached
epithelium 0.97 mm = 2.04 mm.
The size of the gingival groove is 0.69 mm.
62. *Vertical preparation
There are two main types of vertical preparation (vertiprep):
• Preparation without the actual ledge (finish line), but with a
bevel, not reaching the bottom of the gingival sulcus; knife edge
• Preparation without marking any visible border to the bottom of
the gingival sulcus (b.o.p.t.)
63. Bottom of the tooth gingival
sulcus.
In the b.o.p.t. method, the edge
of the artificial crown is pushed to
the bottom or just above
Half the depth of the tooth
gingival sulcus.
Vertical preparation with a bevel.
68. Create a gum contour after
using temporary crown
69. In b.o.p.t. preparation, the gum is
injured - the edge of the temporary
crown is set above the gum level - gum
is often raised, closing the recession
after regeneration.
70. Metal garland
For vertical preparation, it is recommended to use:
• AC with a garland or metal or with zirconium
dioxide
• All‐Zirconium crown
• All‐metal crown
Since the edge of the crown should be like a knife
blade, these materials are tough enough, then
ceramics, to withstand forces.
72. *Preparation stages:
1. Psycho‐emotional preparation of the patient
2. Anesthesia (if necessary)
3. Separation of contact surfaces
4. The incisal edge / occlusal surface;
5. Vestibular and oral surfaces;
6. Removing sharp edges, polishing.
A specific sequence of surface reduction is optional.
But it should be noted that all surfaces of the teeth are processed
when preparing for a full artificial crown.
73.
74.
75.
76. One of the options of preparation:
а – is the reduction of the equator;
б – work in the first plane with the creation of a ledge, bur is plunged in only half its
diameter in order to avoid the formation of a groove.
в – work in the second plane.
г – polishing, make a smooth surface with a low-abrasive bur (yellow marking).
а б в г
77. After separation of the contact points, the same
bur or bur with the smallest diameter is taken,
then it gradually replaced with a large diameter
and hard tissues preparing until the necessary
result is obtained.
It is not desirable to use large diameter bur at fist
step.
Separation (disconnection) of contact surfaces - with a sharp-tip
bur with diamond spraying or with a separation disc.
78. Reduction control
Marker bur – used for creation of grooves, the bottom of which with a pencil or
permanent marker is marked, and by round-end tapered bur is removed to the
stained marks. It is produced to control the tissue preparing.
81. The oral surface of the front tooth groups is reduced by olive bur.
Occlusion (chewing/incisal) surface - cylinder or olive bur is used.
82. We can prepare vestibular, oral, contact surfaces by cylinder and
tapered diamond bur.
A ledge is made by the tip of a cylinder bur (threads may be
used when the ledge is under the gum level).
After all the reduction steps, the surface of the tooth must be
polished (smoothing) - produced by discs, arkansas, bur with
yellow and red markings at low speed.
And before fixing for better retention we may do sandblasting
(for example, 23-27 microns of aluminum oxide)
83. Rotation transmission with increasing speed (Red colour marking).
The speed of the bur rotation in the turbine handpiese is regulated
by the degree of pressing on the pedal, and the speed increasing
handpiece is regulated by the speed mode on the block/remote
control of the electric motor.
1:2—1:10 type – rotation speed is — 5 000 - 230 000 rpm.
Speed increasing handpiece
85. *Functions of temporary crowns:
1. Protection of prepared dentine from thermal and chemical
trauma.
2. Maintenance of esthetics and function.
3. Maintenance of gingival position, contour and health.
4. Maintenance of good oral hygiene.
5. Maintenance of occlusal stability and prevention of supra
eruption.
86. Take impression before preparation.
Cast diagnostic gypsum models on
which dental technician make wax
model and take impression (silicon
key) from these «wax up».
Or we can take impression from
tooth directly in the mouth.
87. Remove old structure (if there is
any) and prepare supporting teeth.
In the silicone key
(imprint) insert self-
hardening composite
(plastic) - bis -acrylate
88. Introduction and application of silicone key with bis - acrylate plastic,
remove of excess, and we get plastic construction (crown).
Polishing.
Silicon key
99. *Impression
One-stage dual-phase
Two-stage dual-phase
Correct selection of spoon, if necessary adhesion application.
Retraction (threads, gel): the 1st thread is vertical retraction (small diameter, is
inserted completely), the 2nd thread (or paste) horizontal retraction (larger
diameter, is inserted with half the diameter), which is removed before the
correction mass is applied). Ideally, thread duration in gingival sulcus not
exceeding 10 minutes.
100. *Steps of Try-In
1. Evaluation of the quality of AC production
(there must be no defects);
2. Fitting AC on teeth («Clinical requirements to
AC»);
3.Check inter-occlusion contacts with articulation
paper.
101. *Clinical requirements for artificial
crowns (AC)
1. Artificial crown should restore the morphology of the tooth ‐ the
anatomical shape of the tooth, the volume;
2. Marginal fit (the edge of the AC) should tightly cover the neck of the
tooth. If there is a ledge (finish line), then the edge of AC must reach the
ledge of teeth;
3. . The edge of the AC should plunging in the gingival pocket on: 0.1 ‐ 0.2 mm
for young people; 0.3 ‐ 0.5 for the elderly, so as not to
damage the circular ligament of the tooth.
4. The edge of the AC should follow the gum relief around the tooth;
5. AC should restore interocclusal contacts with antagonist teeth and
interalveolar height (in central and lateral occlusions) and contact
points.
6. The AC should not balance (swing) on the preparing tooth.
102. Edge fit (smooth transition,
no retention points, micro
crevices, minimum cement
gap)
Hypo and hyper contour should be absent.
Hypercontours, for example, may lead to difficulties
in cleaning and result in inflammatory diseases of
surrounding teeth tissues.
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Construction is
balance (swing)
No balance (swing)
103. *AC fixation
In fixation of artificial crown the material from which the construction is made play
the main role.
Metal, metal – ceramic – glass ionomer cement – GIC
Ceramic – composite cement with adhesive protocol.
Zirconia oxide – self-adhesive cement with adhesive protocol.
Adhesive protocol shortly:
Insulation by cofferdam/rabberdam.
Tooth surface preparation:
• Sandblasting. Etching with 37% phosphoric acid, primer to the dentin, adhesive
on enamel and dentin.
Ceramic surface preparation:
• Etching with 20 seconds of hydrofluoric acid 5%, etching with 20 seconds with
37% phosphoric acid.
• Ultrasound preparation, silane, adhesive.
Fixing on composite cement. Polishing.
105. *AC fixation on cement
1. Remove the temporary structure from the tooth;
2. The remaining temporary fixing material shall be removed from the tooth
surface;
3. Insulation and dryness of working field (cofferdam/cotton wool rollers, saliva
ejector);
4. The tooth and artificial crown shall be thoroughly treated with antiseptic;
5. Dry the tooth and artificial crowns (with air);
6. Put the processed AC in a sterile place. Meanwhile, the cement is mixed.
106. *AC fixation on cement
7. Cement is mixed on paper notebook or smooth side of glass with a
spatula, comply with powder/liquid ratio:
More often, two drops of liquid are taken to one spoon of powder;
The powder is added to the liquid and thoroughly crushed with a spatula
on a paper pad or glass until a uniform (homogeneous) consistency is
obtained;
Mass should resemble liquid cream in consistency.
107. *AC fixation on cement
8. The cement is then inserted into the crown with a spatula, filling it
with 1/3 in volume. Put some mass on the internal walls to the edges
of the crown;
9. The crown with a cement are fixed on the tooth. Watch that the
cotton wool rollers do not fall under the edge of the crown.
108. *AC fixation on cement
10. Check occlusion relationship in central occlusion with articulating paper.
11.Remove excess of the cement.