Occlusion in conservative dentistry

1. PRESENTED BY :
Dr Boris Saha (JR2).
Supervisor : Prof Ashok
kumar
Co supervisor : Dr Mukhtar

2. 
CONTENTS
 INTRODUCTION
 GENERAL ASPECTS OF OCCLUSION
 CLINICAL SIGNIFICANCE OF OCCLUSION
 FORCES ACTING ON RESTORED TEETH
 OCCLUSAL CONSIDERATIONS IN RESTORING INDIVIDUAL
TEETH
 MODES OF RECORDING OCCLUSAL RELATIONS
 FINAL CHECKING OF THE CASTING FOR OCCLUSION

3. 
 MANAGEMENT OF TOOTH WEAR & TRAUMATIC
OCCLUSION
 FEATURES OF AN OPTIMUM OCCLUSION
 CONCLUSION
 REFERENCES

4. 
 Occlusion literally means ‘closing’
 An ideal occlusion may be defined as the most
dynamic position, arrangement and relationship of
one tooth with another tooth of one arch with
another arch and of both the arches with the base of
skull so as to perform the optimal functions of
mastication, phonetics and esthetic maintaining the
integrity and longevity the individual tooth and the
stomatognathic system
Introduction

5. 
General aspects of
occlusion

6. 
TOOTH ALIGNMENT & DENTAL
ARCHES
Dental arch cusp & fossa alignment
Maximum intercuspation

7. 
SUPPORTING CUSPS
Mandibular supporting
cusps are located on the
facial occlusal line.
Mandibular supporting cusp in
opposing maxillary fossa
Maxillary supporting cusp in
opposing mandibular fossa

8. Supporting cusps are located on the
lingual occlusal line in maxillary arch.

9. 
NON SUPPORTING CUSPS
Maxillary nonsupporting cusps
are located on the facial occlusal line &
mandibular non supporting cusps are
located on the lingual occlusal line.
Maxillary
nonsupporting
cusp overlapping
mandibular tooth
Mandibular
nonsupporting
cusp overlapping
maxillary tooth

10. 
Interarch tooth relationship

11. POSTERIOR CUSP CHARACTERISTICS

12. Pattern of cusps and
grooves are
similar to mortar and
pestle for
crushing food.
Mesial and distal
triangular fossae
define marginal ridges
and sharpen occlusal
contacts.
Supplemental grooves
widen
pathways for opposing
cusp
movement.

13. 
 Occurs in the segment of arch towards which the mandible moves & is
divided into two –
Lateral functional occlusion
Protrusive functional occlusion
 Lateral functional occlusion :
Facial range – involves mandibular facial cusps moving from
their area of centric contact facially & slightly distally across the
lingual inclines of maxillary facial cusps.
Lingual range – involves the tracking of maxillary palatal
cusp tip from their areas of centric contact up the facial inclines of
mandibular lingual cusps lingually.
FUNCTIONAL OCCLUSION

14.  Protrusive functional occlusion :
- Occurs when the mandible moves forward.
- The reminder of the posterior teeth should be discluded by the
guiding influence of anterior teeth during protrusive excursion.
NON FUNCTIONAL OCCLUSION
 Lateral non functional occlusion :- Contact occurs on the opposing inclines
between the two zones of centric contact.
 Protrusive non functional occlusion :- The facial range occurs when the mesial
cusp ridges of mandibular facial cusps contact the distal slopes of triangular
ridges of maxillary facial cusps.

The lingual range of protrusive contacts occurs when distal cusp ridges of
maxillary palatal cusps contact the mesial slope of triangular ridges of
mandibular lingual cusps.

16. POTENTIAL CONTACT AREAS OF THE OCCLUSAL SURFACE

17. CENTRIC RELATION
 Centric relation is the position of mandibular
condyle in articular fossa in an unstrained
position where antero-superior surfaces of the
condyle are in contact with the concavities of
the articular disc.
 Terminal Hinge axis
 Terminal arc of closure

18.  Centric occlusion is the intercuspal
contact position .
 Upon closure of mandible in centric
relation, the mandible slides forward to a
position where the maxillary and
mandibular teeth intercuspate maximum
in centric occlusion.

19. OCCLUSAL SCHEMES
- Balanced occlusion
- Canine protected occlusion
- Group functional occlusion

20. GUIDANCE OF OCCLUSION
Supporting cusps/ Centric holding cusps / Stamp cusps :
1. Contact opposing tooth in MI
2. Support vertical dimension
3. Nearer facio lingual center of tooth than non supporting cusps
4. Outer incline has potential for contact
5. More rounded than non supporting cusps

21. Non – supporting cusps / Non centric holding cups /Shear
cusps :
1.Do not contact opposing tooth in MI
2. Keep soft tissue of tongue or cheek off occlusal table
3. Farther from facio lingual center of tooth than
supporting cusps
4. Outer incline has no potential for contact
5. Have sharper cusp ridges than supporting cusps

22.  Guiding inclines
 Incisal guidance
 Condylar guidance :
Contour of articular eminence of the
temporal bone
Bennett shift
Inter-condylar distances

23. Cusp angle
Plane of occlusion
Curve of spee
Curve of Wilson

24. CLINICAL SIGNIFICANCE OF
OCCLUSION

25. A through occlusal examination is a must
before initiating any restorative work.

26. The occlusion effects almost every part of the stomatognathic
system :
 Pulpal considerations.
 The proximal relations.
 Buccolingual relations
 Labiolingual relations

27.  Periodontal considerations
Clinical signs of traumatic occlusion :
• Recession of gingiva
• Enlargement of the gingiva
• Festoons
• Mobility of teeth of varying degree
• Stillman's clefts
• Periodontai pockets
• Abnormal wear of teeth
• Congestion of the marginal gingiva

28. • Periodontal abscess
• Cheek biting
• Bruxism
• Gingival irritation
• Absence of stippling
• Sharply demarcated linear depressions in the
alveolar mucosa, parallel to the long axis of the
root and overlying the septal bone
• Distended veins in the oral mucosa

29. RADIOGRAPHIC SIGNS OF
TRAUMATIC OCCLUSION

30. FORCES ACTING ON RESTORED
TEETH

31. Forces acting on tooth during
centric occlusion
Forces acting on tooth
during chewing

32. Schmatic view of occlusal loading of amalgam restorations.
A, Stress transfer into an unrestored tooth occurs
through dental enamel into dentin. B, Stress transfer into a
tooth restored with dental amalgam is conducted through
enamel and the restoration to be distributed within dentin
( and not enamel). Note the facial and lingual seats at initial
cavity preparation at the pulpal wall level (before removal of
remaining infected dentin and placement of base) that help
transfer stresses laterally.

33. Significance of Marginal ridge
Significance of Occlusal embrasure

34. OCCLUSAL CONSIDERATIONS IN
RESTORING INDIVIDUAL TEETH

35. Restoring the normal anatomical form of an individual tooth should result in :
- Correct relationship with adjacent teeth
- Correct relationship with opposing teeth
- Correct buccolingual contour
- Proper oral hygiene maintanance
- Esthetics

36. Modification of the occlusal table :
 Reduction of force
 Reduction of the effect of force
 Reduction of torque
 Facilitation of oral hygiene & reduction of soft
tissue biting

37. POSTERIOR RESTORATIONS
 Opposing occlusal surface should be examined .
 Malpositioned opposing supporting cusps & ridges should be
recontoured .
 Articulating paper should be used to register the centric
holding spots.
 Plunger cusps & over erupted teeth should be reduced.
 An onlay is an excellent restoration to restore occlusal plane of
a mesially tilted molar.

38. ANTERIOR RESTORATIONS
 The lingual area is carved to maintain the
anatomy of cingulum & the lingual marginal
ridges.
 Interferences in protrusive movements are also to
be assessed.

39. Cuspal interfernaces :

40. MODES OF RECORDING
OCCLUSAL RELATIONS

41. MODES OF RECORDING & REPRODUCING
MANDIBULAR MOVEMENTS
Physical manipulation of the mandible for occlusal records:
I . Place the mandible in centric relation
II. Locate the centric occlusion
III. Define lateral excursions
IV. Protrusive movements

42. TRANSFERABLE RECORDS
 STATIC RELATIONSHIP TRANSFERABLE RECORDS:
- These records capture the relationship of the maxillary and
mandibular teeth at border locations of the mandibular
movement path.
- They are only transferable to semi-adjustable articulator
which is capable of moving from one border location to
another with a standard path in between.
- Modified zinc oxide eugenol, impression plaster , silicon
rubber base impression material , autopolymerizing acrylic
resin can be used for interocclusal records.

43.  The interocclusal records can be transferred to
- Hinge articulator
- Semi-adjustable articulator
 Hinge articulator is used when the occlusion is stable &
within adequate holding cuspal elements on both the
sides.
 Semi-adjustable articulator needs a facebow transfer ,
which is a record capturing the relationship of maxilla to
the cranium.

44. Simple hinge Semi-adjustable non-arcon,
Semi-adjustable arcon Fully adjustable.

45. Denar Slidematic facebow,
Dentatus facebow

46.  The facebow records the relationship between the
patient’s terminal hinge axis, and the maxillary teeth &
enable this to be transferred to the articulator, so relating the
hinge axis of the articulator to the maxillary cast.
 The arbitrary hinge axis is adequate for most clinical
procedures.
 It is located 13 mm from the tip of the tragus of the ear on
a line joining this point to the outer canthus of the eye.
This point is marked on the face and the condylar rod of the
facebow placed over it.

47.  Some facebows use the ear as the point of reference; this
is more accurate than other average points marked on the
Face and simplifies the clinical recording process.
 The third reference point relates the maxillary cast to the
Frankfort plane.
 Some facebows use the infra-orbital notch and others have
a plastic ‘nose piece’ that rests on the bridge of the nose
during the recording.
 The occlusal plane in its sagittal relationship to the
horizontal is then identified.

49. DYNAMIC RELATIONSHIP TRANSFERABLE
RECORDS
 Functionally generated path
 Pantograph & fully adjustable articulator
 Stereographic tracing & fully adjustable articulators

50. NON - TRANSFERABLE RECORDS
- Used only for diagnostic or verifying purposes. The
interferences noted during markings are recorded.
The following one or all features are important and should
be noted before a final restoration :
 Uneven, non-symmetrical attrition of occluding teeth.
 Supra-eruption, tilting, rotation or bodily movements of a
tooth.
 Undercontoured (overcarved) occluding restoration
leading to occlusal and possibly lateral displacement of
opposing cuspal elements.

51.  Periodontal diseases facilitating tooth
movement, especially laterally.
• Insufficiently restraining cusp-fossa or cusp-
marginal ridge relationship allowing
repositioning of teeth.
 Plunger cusps against marginal ridges
separating them or the same cusp against one
side of tooth tilting it laterally.

52. FINAL CHECKING OF THE
CASTING FOR OCCLUSION

53. Methods for detecting premature contacts
 Study casts
 Roentgenograms
 Palpation
 Visual examination
 Patient’s tactile response
 Impressions on wax
 Articulating paper

54. 
Occlusal analysis
 Qualitative methods
 Quantitative methods

55. QUALITATIVE METHODS
1. Wax
2. Articulating paper
3. Foils
4. Silk strips/Ribbons
5. Pastes, sprays, and paint-on materials

56. ARTICULATING PAPERS
 These are frequently used; the width, thickness, and dye type of
the articulating paper enables it to leave a mark of either a point or a
surface.
 The major disadvantages of articulating papers are that they can be
easily ruined by saliva, they are thick and are relatively inflexible
materials; all of these factors results in a greater number of pseudo-
contacts.

57. Depending on the physical properties of registration strip, a product
may mark the actual contact area or generate a misleading smear or
smudge in a non-contacting area.
These are available in different thicknesses:
200,100 μm= thin
60, 40 μm= Micro-thin
11 μm= Ultra-thin

59. FOILS
 Foils are the thinnest indicator material; they give more accurate
results than paper or silk .
 Foils produces the highest sensitivity values compared to other
recording materials.
 Greater pressure must be applied because their marking capacity is less
evident, under reduced pressure and on glossy surfaces.

60. PASTES, SPRAYS AND PAINT-ON MATERIALS
 They can be painted and sprayed on tooth contact, and then the
material is perforated so that the contact areas are made visible.
 Use of such materials can be very accurate because of thin film.

62. SILK STRIPS/RIBBONS
 Silk strips are the best material for indicating occlusal contacts.
 These soft indicator materials do not produce pseudocontact markings
because of their texture.
 They can lose marking abilities when their stain components are dried,
and also can be ruined by saliva.

63. QUANTITATIVE METHODS
With the quantitative method of evaluating occlusal relationships, the
sequence and density of the contacts CAN be differentiated.
Methods used for Quantitative occlusal analysis:
1) Photocclusion (By ARCAN)
2) Computer-assisted dynamic occlusal analysis (By MANESS)

64. PHOTOOCCLUSION
For precise determination of occlusal harmony, it is necessary to
determine the sequence of tooth contacts for any given jaw
relationship.
Photoocclusion was the first clinical
system for quantitative analysis by
measurements of the strains induced in a
photoplastic wafer, called a “memory sheet”.
In this system, a thin photoplastic film is placed on the
occlusal surface of the teeth; the patient is then asked to occlude
on the film layer for 10 to 20 seconds. The film layer is inspected
under a polariscope light for birefringence patterns.

65. It is possible to determine minute differences in space between the
first contact and the teeth that are not yet in contact.
The intensity order of the contacts can be distinguished by
variations of color that appear on the screen. The black
background relates to zero. From that point, a progression of color
proceeds through a clearly defined sequence of grey, white, yellow,
orange, and red. Each color represents a step higher on the contact-
intensity level.
This method has great value, not only as an aid in diagnosing
occlusal disharmony, but also as a record of pre- and post treatment
occlusal relationship.

66. COMPUTER-ASSISTED DYNAMIC OCCLUSALANALYSIS
T-Scan system consist of a piezoelectric foil sensor, sensor handle, system unit and
both hardware and software for recording, analyzing and viewing the data.
The u-shaped sensors foil is 60-m thick, consists of an X-Y coordinate system
with 1500 sensitive receptor points made of conductive
ink, and is subjected to elastic deformation.
When the patient occludes on the sensors, the particles come together in the force-
applied areas, diminishing the electrical resistance.

67. The Tek-Scan system is practical in that:
1.It allows direct real-time recording of occlusal contacts to be shown
on a monitor during any phase of functional jaw movements.
2. It also allows the operator to record contacts at any jaw relationship
either on the monitor or on a printout.

68.  The height of the column indicates relative timing of the contact or
relative force. The highest column is the first contact, red in color at time= 0 sec.
 Displays contact pattern before and after treatment.
 Can be used to test reproducibility of jaw closure.
 Designed to establish occlusal histories.

69. Disadvantages of T-scan:
 Sensors do not have the same accuracy among themselves.
 Sensitivity of sensors was found to be lower than that of the other
recording materials.
 Their thickness and low elasticity may limit its clinical usefulness.
 It does not measure the force accurately.

70. MANAGEMENT OF TEETH WEAR
& TRAUMATIC OCCLUSION

71. APPEARANCE IS SATISFACTORY
 Patient counselling
 Conventional restorative treatment
- Exposed pits are filled
- Occlusal disharmony is corrected
- Consideration to be given to crown lengthening
procedure

72. APPEARANCE IS UNSATISFACTORY BUT THERE IS
NO NEED TO RAISE THE VERTICAL HEIGHT
 Teeth are restored , preferably with all ceramic crowns or
laminates .
 Occlusal guard for protection against nocturnal clenching
l

73. APPEARANCE IS UNSATISFACTORY & THERE IS A
NEED TO RAISE THE VERTICAL HEIGHT
 Generalized increase in vertical height is required.
 Orthodomic tooth movement can be used for over-
eruption of posterior teeth creating space for the anterior
teeth.
 Space has to be utilized in retruded cusp position (RCP)
and intercuspal position (1CP).

74. MANAGEMENT OF GENERALISED TOOTHWEAR

75. 
MANAGEMENT OF LOCALISED
ANTERIOR TOOTHWEAR

76. MANAGEMENT OF LOCALISED POSTERIOR TOOTHWEAR

77.  Selective reduction of occlusal areas is done to eliminate
injurious occlusal forces & to provide functional
stimulation for the preservation of periodontal helath.
 The steps involved are :
Grooving
Spheroiding
Pointing

78. FEATURES OF AN OPTIMUM
OCCLUSION

79. 1. There should be no tooth contact at the early stage of
centric relation.
2. The mandible should arc along a hinge axis from centric
relation to centric occlusion.
3. In the early stages of centric occlusion towards complete
intercuspation, there may be forward movement of
mandible. However, there should not be any lateral,
medial or backward movement of mandible (with the
teeth) when moving from centric relation to centric
occlusion.
4. At centric occlusion, the holdings cusp should be of
sufficient height to be in positive contact with their
opposing counterparts. Such an arrangement preserves the
vertical dimension of the teeth maintaining the
stomatognathic system.

80. 5. At centric occlusion, the holding markings should be
symmetrical in magnitude and extent on all holding cuspal
elements of both sides.
6. When maximum intercuspation is achieved, there should
not be any further movement of mandible or the teeth.
7. Holding cusps occluding with more than one tooth or
eccentrically occluding with opposing teeth should not move
opposing teeth in a non-axial direction.
8. In centric occlusion, the incisal edges of lower incisors
should be located at the gingival side of the lingual concavity
of the upper incisors, preferably with a flat horizontal shelf or
plane.
9. In lateral excursion of the mandible, there should not be
any tooth contact on the non-working side of mandible.

81. 10. In lateral excursion of mandible, the holding cusps of the
working side should have a valley like space on the
opposing teeth (grooves or occlusal embrasures).
11. The disclusion should start posteriorly and end by the
cuspid's disclusion.
12. The disclusion path should be perfected so that the
optimum direction along the lingual surface of the upper
cuspid and the working inclines of the non-working cusps
is achieved.

82. 13. Marked contact areas during lateral excursion
should be the same when going out of centric and
back into centric.
14. During protrusive excursions of mandible there
should not be any tooth contact posteriorly.
15. Cuspids should be involved at least in the initial
stages of the protrusive movement of mandible.
16. Protrusive contact markings should be evenly
distributed and symmetrical on all teeth involved.

83. 
The criteria for diagnosing occlusal problems and the
indications for treatment are based on an assessment of the
health and function of each individual’s masticatory
system. The implication is that individuals do not
necessarily fit into a prescribed occlusal concept but that
each occlusion should be Considered separately and
treatment needs to be tailored to individual requirements.
CONCLUSION

84. 
REFERENCES
1. Dent Update 2003; 30: 150-157
2. cda j o u r n a l , vo l 3 6 , n o 8
3. WHEELER’S DENTAL ANATOMY ,
PHYSIOLOGY & OCCLUSION
4. ART & SCIENCE OF OPERATIVE
DENTISTRY , 4TH edition , Sturdevant .

85. 
5. TEXT BOOK OPERATIVE DENTISTRY , 2ND edition
,Vimal sikri .
6. Phillips’ SCIENCE OF DENTAL MATERIALS – 11th
edition , Kenneth J. Anusavice .
7.Fundamentals Of Fixed Prosthodontics – 3rd edition ,
Herbert T.Shillinburg

86. Thank you 