The document discusses occlusal considerations for implant-supported prostheses. It introduces various occlusal terminology and explores the significance of occlusion on osseointegrated implants. The document outlines the goals of implant protective occlusion (IPO), which aims to distribute occlusal forces appropriately to minimize stress on implants and surrounding bone. IPO principles include using thin articulating paper for initial adjustment, equalizing contacts under heavy bite forces, avoiding non-axial and offset loads, and designing the occlusion around the weakest component. The document also discusses factors like implant angulation, crown height, bone quality and the materials used for occlusal surfaces.

1. Occlusal
Considerations
in Implants

2. CONTENTS
 Introduction
 Terminology
 Significance of occlusion on osseoitegrated implants.
 Occlusal goals for implant prosthodontics.
 Implant protective occlusion(IPO)
 Occlusal schemes
 Occlusal adjustment in implant-supported prosthesis
 Conclusion

3. INTRODUCTION
 For many years, in fact, for more than 100 years, dentists and researchers have
debated how to identify and define concepts of dental occlusion that could be
applied in diagnostic and therapeutic situations.
 Occlusion has been, and still is to some extent, a controversial issue in what is
now called conventional removable and fixed prosthodontics, and it is not fully
resolved in implant prosthodontics.

4.  The choice of an occlusal scheme for an implant supported prosthesis is broad
and controversial
 Almost all concepts are based on those developed with natural teeth and are
transposed to implant support systems with almost no modification

5. TERMINOLOGY (GPT 2005)
 Occlusion :
1: The act or process of closure or of being closed or shut off.
2: The static relationship between the incising or masticating
surfaces of the maxillary or mandibular teeth or tooth analogues.
 Balanced articulation :
The bilateral, simultaneous, anterior and posterior occlusal contact of teeth in
centric and eccentric positions

6.  Lingualized occlusion :
First described by S. Howard Payne, DDS, in 1941, this form of denture
occlusion articulates the maxillary lingual cusps with the mandibular occlusal
surfaces in centric working and nonworking mandibular positions.
 Mutually protected articulation :
An occlusal scheme in which the posterior teeth prevent excessive contact
of the anterior teeth in maximum intercuspation, and the anterior teeth
disengage the posterior teeth in all mandibular excursive movements.
 Group function occlusion:
An occlusal scheme in which lateral pressure are distributed to all working
side teeth in contrast MPO where lateral pressure are directed only to the
working side canine.

7. SIGNIFICANCE OF OCCLUSION ON THE
OSSEOINTEGRATED IMPLANTS
 There are no specific defense mechanisms against occlusal forces in implants:
poorly restored occlusion  deleterious effect.
 Prosthesis must be fabricated as accurately as possible in order to achieve long
standing success and occlusion should be key factor in overall success rate.
 Haraldson suggested that in pts OIP, occlusal forces are controlled through
neuromuscular mechanisms via masticatory muscles.
 An impact force can have destructive effects on prosthesis and implants and
supporting bone.
 Teeth should contact simutaneously when mandible closes into maximum
intercuspal position

8. OCCLUSAL GOALS FOR IMPLANT
PROSTHODONTICS
 Bilateral simultaneous contact.
 No prematurities in retruded contact position. (RCP)
 Smooth, even, lateral, excursive movement with no nonworking interferences.
 Equal distribution of occlusal forces.
 Freedom from deflective contacts in intercuspal position (IP).
 Anterior guidance whenever possible

9. IMPLANT PROTECTIVE OCCLUSION(IPO)
 A poor occlusal scheme both increases the magnitude of loads and intensifies
mechanical stresses (and strain) at the crest of the bone.

10.  IPO was previously known as medial positioned-lingualized occlusion. This
occlusal concept refers to an occlusal plane that is often unique and specifically
designed for the restoration of endosteal implant.
 A primary goal of IPO is to maintain the occlusal load that has to be transferred
to the implant body within the physiologic limits of each patient.

11. IPO adresses several conditions to decrease stress to implant interface

13. Timing of occlusal contacts:
 The implant has no periodontal membrane, concerns center around the potential
for the “nonmobile” implant to bear the total load of the prosthesis when joined
to the “mobile” natural tooth.
 Four important components may contribute movement to the system:
implant, bone, tooth, and prosthesis.

14.  The initial difference in vertical
movement of teeth and implants
in the same arch – 28
 Initial occlusal contacts should
account for this difference or
implants will sustain greater
loads

15.  Occlusal prematurities are ideally eliminated on teeth
before implant reconstruction.
 Thin articulating paper (less than 25m thickness) is then
used for the initial implant occlusal adjustment in centric
relation occlusion under a light tapping force.
 The implant prosthesis should barely contact, and the
adjacent teeth should exhibit greater initial contacts. Only
axial occlusal contacts should be present on the implant
crown
 Once the equilibration with a light bite force is completed, a
heavier centric occlusal force is applied.

16.  The contacts should remain axial over the
implant body and may be of similar
intensity on the implant crown and the
adjacent teeth under greater bite force to
allow all elements to react similar to the
occlusal load.
 Hence to harmonize the occlusal forces
between implants and teeth, a heavy bite
force occlusal adjustment is used because it
depresses the natural teeth, positioning
them closer to the depressed implant
position and equally sharing the load.

17.  The initial lateral movement of
healthy anterior teeth ranges from 68
to 108m before secondary tooth
movement.
 Anterior implant movements are not
immediate and range from 10 to
50m.
 Because of the greater discrepancies
in lateral movement, the occlusal
adjustment in this direction is more
critical to implant success and
survival.

18.  A similar scenario is used for the occlusal equilibration - implants joined to
natural teeth
 A light force and thin articulating paper are used, and the implant crown
exhibits minimum contact compared with the natural abutment crown.
 A heavy bite force is then used to establish equal occlusal contacts for all
abutments and the entire prosthesis, whether implant or natural.

19. Influence of surface area:
 An important part of IPO is the adequate surface area to sustain load
transmission to the prosthesis.
 Wider diameter root form implants have a greater area of contact at the crest
than narrow implants which reduces the mechanical stress at the crest.
 When narrow diameter implants are used in regions that receive greater loads,
additional splinted implants are indicated to compensate for the design.
 Placement of implants in posterior jaws to be staggered to improve
biomechanical loads.

20. Implant body orientation and
influence of load direction:
 Forces acting on dental implants are
referred to as vectors (defined in both
magnitude and direction).
 Occlusal forces are typically three-
dimensional, with components
directed along one or more of the
clinical coordinate axes.

21.  Implants are also designed for long axis load.
 Axial load generates greater proportion of compressive stress than tension and
shear.

22. Bone mechanics and force direction:
 Anisotropy refers to the character of bone, whereby its mechanical properties,
including ultimate strength, depend on the direction in which the bone is loaded.
Whenever possible bone should be loaded with compressive load

23. Strength of cortical load decreases with increasing angle of applied load

24.  The primary component of the occlusal force should therefore be directed along
the long axis of the implant body, not at an angle.
 Angled abutments are used only to improve the path of insertion of the
prosthesis or the final esthetic result.
 Larger diameter implants or a greater number of implants are indicated to
minimize the crestal bone stress on each abutment.
 IPO aims at reducing the force of occlusal contacts, increasing implant number,
and/or increasing implant diameter for implants subjected to angled loads.

25. Crown cusp angle:
 Occlusal contact along an
angled cusp result in an angled
load to the crestal bone.
 Post implant crown should have
wider central fossa
perpendicular to implant body.
 Opposing cusp should be
modified to occlude in fossa
Natural tooth 30 deg Wide central fossa

26. Cantilevers and IPO:
 Cantilevers or crowns with less favourable crown/implant ratio also increase
the amount of stress to the implant.
 The goal of IPO relative to cantilevers is to reduce the force on the lever or
pontic region compared with that over implant abutments.
 In addition no lateral load is applied to the cantilever portion.

28. Crown height and IPO:
 The implant crown height is often greater than the
original natural anatomical crown, even in division A
bone.
 Crown height with a lateral load may act as a
vertical cantilever and a magnifier of stress at the
implant-to-bone interface.
 Therefore the noxious effects of a poorly selected
cusp angle, an angled implant body, or an angled load
to the crown will be magnified by the crown height
measurement

29. Occlusal contact positions:
 Determines the direction of force.
 The marginal ridge contact is also a cantilever load because the implant is not
under the marginal ridge

30.  The ideal implant body position is usually
under the central fossa and maybe 1-2mm to
the facial aspect (when bone is abundant) to
be under the buccal cusp of the mandible and
to improve the esthetic emergence of
maxillary implant crowns.
 The ideal primaty contact should reside
within the diameter of an implant.
 secondary occlusal contact should remain
within 1 mm of the periphery of implant
 Marginal ridge and buccal cusp contacts
should be avoided.

31. Implant crown contour:
 A wide occlusal table favors offset contacts
during mastication or parafunction.
 Narrower implant bodies are even more
vulnerable to occlusal table width and offset
loads.
 Wider root form implants can accept a broader
range of vertical occlusal contacts while still
transmitting lesser forces at the permucosal
site under offset loads.
 Therefore in IPO the width of the occlusal
table is directly related to the width of the
implant body.

32.  Restorations mimicking the occlusal anatomy of natural teeth often result in
offset loads (increased stress), complicated home care and increased risk of
porcelain fracture.
 In nonesthetic regions of the mouth, the occlusal table should be reduced in
width compared with natural teeth.

33. Division A Bone:
 In an edentulous ridge with abundant height and
width and little resorption, the implant may be
placed in a more ideal position for occlusion and
esthetics.
 To load implant in axial direction the primary
occlusal contacts should be the central fossa
region in div A bone.
 Thus for maxillary implant opposing mandibular
natural teeth, the mandibular buccal cusp acts as
the primary tooth contact.

34. Canines and premolar – crown contour

35. Division B Bone :
 Division B bone has maxillary and mandibular
implants positioned under the lingual cusp when
compared with the original natural tooth position.
 As a result, mandibular crowns require even more
reduced buccal contours to avoid offset occlusal
contacts.
 The primary contact of occlusion on an opposing
natural posterior maxillary tooth is the lingual cusp,
which is reshaped to axially load the implant

36.  A Division B maxillary implant is often placed under
the palatal cusp region of the original natural tooth.
 The maxillary occlusal table cannot always be
reduced from the facial aspect for esthetic reasons;
therefore the buccal cusp is offset facially but left
completely out of occlusion (as with natural teeth) in
centric relation occlusion and during all mandibular
excursions.
 The buccal cusp of the opposing natural tooth is
recontoured in width and height to reduce offset loads
to the opposing crown on the maxillary implant.

37.  When Division B implants are placed in both
arches, the maxillary and mandibular
prostheses are similar to that described in the
previous scenario.
 However, it is usually not possible to load
both arches with an axial load, so the weakest
implant in bone density, width, or prosthesis
type determines the axial load, because it is
the most vulnerable arch.

38.  When further resorption occurs and the ridge evolves into Division C or D, the
maxillary palatal cusp becomes the primary contact area, situated directly over
the implant body.
 Hence the occlusal contacts differ from those of a natural tooth and may even
be positioned more medial than the natural palatal cusp when the implant is
placed in Division C or D bone.

39. Design to the Weakest Arch:
 The weakest component philosophy is used when one opposing segment is at
more risk of complications than an opposing area.
 The amount of force distributed to a system can be reduced by stress relieving
components that may dramatically reduce impact loads to the implant support.
 The soft tissue of a traditional completely removable prosthesis opposing
implant prosthesis is displaced more than 2 mm and is an efficient stress
reducer.
 Lateral loads do not result with as great a crestal load to the implants because
the opposing prosthesis is not rigid.

40.  The weakest component philosophy also applies to axial occlusal contacts in
implant body in the presence of cantileveres and offset loaded areas.
 Absence of centacts during excursion on post cantilevers and ant offset pontics
is recommended which minimizes the loads on the terminal implant abutments
 When cantilever pontics are in both arches, they should oppose each other.
 If cantilever pontic is present only in one arch it is better for mandibular
cantilever pontics to oppose maxillary implants than the reverse situation.

41. Full – Arch Fixed Prosthesis:
 Fixed prostheses on natural teeth opposing FP-1 to FP-3 implant restorations
should follow mutually protected occlusal schemes whenever possible.
 In protrusion, there should be total absence of posterior contacts, especially for
cantilevered posterior units.
 The masticatory force generated during lateral excursions is decreased in
absence of posterior contacts. This assists in reducing the noxious effect of
lateral forces on the anterior implants.
 Minimal occlusal contact in the cantilevered regions in centric and the total
absence of posterior lateral contacts during excursions are indicated when
opposing the natural dentition or a fixed restorations.

42.  Mandibular flexure distal to mental foramen demands the placement of implants
in two separate units, total of 7-8 implants to support a complete implant
prosthesis in the mandible for a fixed restoration opposing a fixed prosthesis or
natural teeth.
 In the edentulous maxilla, flexure of the bone is not a concern. A full arch
prosthesis may be fabricated in one section.
 Eight to ten maxillary implants most often are required for a twelve unit fixed
prosthesis opposing a fixed dentition on teeth and / or implants.

43. Occlusal materials:
 The materials selected for the occlusal surface of the prosthesis affect the
transmission of forces and the maintenance of occlusal contacts.
 Occlusal material fracture is one of the most common complications for
restorations on natural teeth or implants.
 Occlusal material for each individual restoration must be considered.
 Occlusal materials maybe evaluated by esthetics, impact force, a static load,
chewing efficiency, fracture, wear, interarch space requirements, and accuracy of
castings.
 The three most common groups of occlusal material are porcelain, acrylic and
metal.

44.  Therefore when all 8 criteria are evaluated, metal is an excellent occlusal
material, with improved properties in accuracy, wear, fracture resistance,
abutment retention, and good qualities for impact or static force.
 Esthetics is best satisfied with porcelain, which has improved properties
compared with acrylic concerning fractures and retention.

45. OCCLUSAL SCHEMES
Rationale for choice of occlusal scheme:
 Occlusal scheme that allows disocclusion of posterior teeth in eccentric
occlusion and reduce lateral stress to dentition, which is accomplisehed by
mandibular and maxillary cuspid.
 In group function lateral forces are distributed to all working side teeth.
 Although they are seemingly divergent philosophies..
 Both philosphies have been helpful in developing occlusal scheme for implant
supported prosthesis.

46. Implant occlusion in partially edentulous patient:
 It is important to differentiate betn ant. Restoration over implants that replace
cuspid and those do not.
Cuspid is not involved: cuspid disocclusion/group function.
Cuspid is involved: group function
 Fixed type restorations opposing partially edentulous maxilla: group function.
 Post fixed implant prosthesis: cuspid disocclusion.
 Singe tooth implant in post segment: cuspid disocclusion.

47. Implant occlusion in edentulous patient:
 No attempt should be made to obtain full balanced occlusion.
 Lingualised type of oclusion id preferred.
 Totally implant borne prosthesis opposes arch with natural dentition: group
function occlusion

48. Single tooth restoration:
 Centric contact – light in casual intercuspation
equal in max intercuspation.
 No contact during excursive movements.
 Occlusal surface should be smaller buccolingually.
 Single missing molars – 2 implants can be splinted
 Occlusal contact should be at centred over implant.

50. Partially edentulous –multiple units
Post. Partial denture
 Centric contact – light in casual intercuspation
equal in max intercuspation.
 No contact during excursive movements.
 This is possible when there is immediate
disocclusion with natural canine

51. Anterior fixed partial denture:
 Centric contact – light in casual intercuspation
equal in max intercuspation.
 The goal should be ant. Grp funcn
 Place contact on multiple implants
 If missing canine is replaced –avoid immediate disocclusion
 Avoid load on single implant during excursive movement or in centric.

52.  Completely edentulous:

60. Standars for different type of osseoingration treatment
Edentulous
Classification
Type of
Prosthesis
Optimal
Occlusal
Scheme
1 Edentulous Fully bone
anchored FPD
MPO
2 Edentulous Overdenture Balanced
Occlusion
3 Class 3 or 4
partially
edentulous
Freestanding
FPD
Group
Function
Occlusion
4 Class 1 or 2
partially
edentulous
Freestanding
FPD
MPO

62. IDJ 2008

63. OCCLUSAL ADJUSTMENT IN IMPLANT-SUPPORTED
PROSTHESIS
 This consists of modifying tooth anatomy to obtain a good occlusion.
 Occlusal adjustments must be performed in the upper and lower arch jointly at
the same time and on both sides.
 All of the following adjustments can be done when checking a case prior to
laboratory work or once it is placed in mouth or in finished cases to readjust
occlusion.


64.  Technique –
 Double colored thin articulating paper or black marking ribbon and the patient
close from CR to MI several times.
 Mandible : In normal occlusion (Class 1) the distal lower inclines and the
mesial upper inclines contact in condylar centric relation.

65.  To adjust, we should follow these steps:
Cusp distal inclines Active-cusp outer inclines
Inner inclines

66.  Maxilla:
Mesial cusp inclines Active-cusp outer inclines
Inner inclines

67. Deepening fossae: maxilla and mandible
 If the cusp contacts the floor of the fossa, it will create
large contact surface; avoided.
 Spare the lateral cusp marks while eliminating the
intermediate zone, which will cause loss of active material
for chewing and will decrease efficiency.
 Deepen the fossa while preserving its lateral aspects,
which will permit preservation of cusp surface.

68.  At the end of this phase of adjustment a great number of black contact points,
not surfaces, will appear on the occlusal surfaces.
 The presence or absence of excessive contact in the anterior teeth must be
checked during closure.
 It should be done with very thin ribbon, noting slight resistance while pulling it
from the teeth.

69. Anterior Guidance:
 The anterior guidance should be as flat as possible to avoid overload in the
anterior teeth in lateral excursion and in protrusion.
 No posterior teeth should contact when the guidance is in function which is
always checked with red ribbon

70. Eliminating interferences:
(Non physiological contacts that appear in anterior and posterior teeth in lateral and
protrusive excursions)
 Using red ribbon have the patient go through working, nonworking and
protrusive movements.
 Next place black ribbon and have the patient close to MI.
 Eliminate all red marking except the guide marks of anterior disclusion.

71. CONCLUSION
 Occlusion has been an important variable in the success or failure of most
prosthodontic reconstruction.
 With natural teeth, a certain degree of flexibility permits compensation for
occlusal irregularity. But “Implants Cannot Bail Out Our Faulty Occlusion”…
 Therefore occlusion must be more rigorously evaluated with implant supported
prosthesis

72. BIBLIOGRAPHY
 Dental implant prosthetics – Misch
 Implant supported prosthessis: occlusion, clinical cases, laboratory procedures - Vicente
Lopez
 Osseointegration and oral rehabilitation – Hobo
 Surgical and Prosthetic techniques for dental implant – Ismail,Fagan,Meffert
 Clinical decision making and treatment plannning in osseointegration.Engleman MJ.
 Implants in dentistry. Black. Kent , Guerra.
 Indication for splinting implant restorations. J oral maxillofc surg. 63; 1642;2005.
 Guidelines for occlusal strategy in implant borne prosthesis. Idj 2008, 58
 Factors to consider in selecting an occlusal concept for pts with implants in edentulous
mandible. JPD 1995; 74; 380

73. Thank you