Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Occlusal considerations for implant / orthodontic seminars
1. OCCLUSAL CONSIDERATIONSOCCLUSAL CONSIDERATIONS
FOR IMPLANT – SUPPORTEDFOR IMPLANT – SUPPORTED
PROSTHESESPROSTHESES
INDIAN DENTAL ACADEMY
Leader in continuing dental education
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2. CONTENTSCONTENTS
INTRODUCTIONINTRODUCTION
OCCLUSAL CONSIDERATIONSOCCLUSAL CONSIDERATIONS
NATURAL TOOTH VS IMPLANT MOBILITYNATURAL TOOTH VS IMPLANT MOBILITY
OCCLUSION ON NATURAL TEETH AND IMPLANTSOCCLUSION ON NATURAL TEETH AND IMPLANTS
IMPLANT ORIENTATION AND INFLUENCE OF LOAD DIRECTIONIMPLANT ORIENTATION AND INFLUENCE OF LOAD DIRECTION
BONE MECHANICS AND OCCLUSIONBONE MECHANICS AND OCCLUSION
OCCLUSAL SCHEMESOCCLUSAL SCHEMES
IMPLANT PROTECTIVE OCCLUSIONIMPLANT PROTECTIVE OCCLUSION
OCCLUSAL MATERIALSOCCLUSAL MATERIALS
CONCLUSIONCONCLUSION
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3. INTRODUCTIONINTRODUCTION
The clinical success and longevity of endosteal dentalThe clinical success and longevity of endosteal dental
implants as load bearing abutments are controlledimplants as load bearing abutments are controlled
largely by the mechanical setting in which theylargely by the mechanical setting in which they
function.function.
Complications reported in follow up studies underlineComplications reported in follow up studies underline
occlusion as a determining factor for success orocclusion as a determining factor for success or
failure.failure.
A passive prosthesis of adequate retention and formA passive prosthesis of adequate retention and form
and a progressive loading to improve the amount andand a progressive loading to improve the amount and
density of the adjacent bone and further reduce thedensity of the adjacent bone and further reduce the
risk of stress beyond physiologic limits.risk of stress beyond physiologic limits.
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4. Implant Protective OcclusionImplant Protective Occlusion
Previously presented asPreviously presented as medial positionedmedial positioned
– lingualized occlusion.– lingualized occlusion.
This occlusal concept refers to an occlusalThis occlusal concept refers to an occlusal
plan that is often unique and specificallyplan that is often unique and specifically
designed for the restoration of endostealdesigned for the restoration of endosteal
implants, providing an environment forimplants, providing an environment for
improved clinical longevity of both implantimproved clinical longevity of both implant
and prostheses.and prostheses.
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5. OCCLUSAL CONSIDERATIONSOCCLUSAL CONSIDERATIONS
Natural tooth vs implant mobilityNatural tooth vs implant mobility
The PDL surrounding the natural teethThe PDL surrounding the natural teeth
decreases the magnitude of stress to the bonedecreases the magnitude of stress to the bone
at the crest, as well as extend the time in whichat the crest, as well as extend the time in which
the load is dissipated.the load is dissipated.
An implant is not as resilient as natural toothAn implant is not as resilient as natural tooth
After occlusal trauma is eliminated, the toothAfter occlusal trauma is eliminated, the tooth
returns to its original condition whereas implantreturns to its original condition whereas implant
rarely returns.rarely returns. www.indiandentalacademy.comwww.indiandentalacademy.com
6. The greater the width of a tranosteal structureThe greater the width of a tranosteal structure
the lesser magnitude of stress transmitted tothe lesser magnitude of stress transmitted to
the surrounding bone.the surrounding bone.
The cross-sectional shape of tooth resistsThe cross-sectional shape of tooth resists
lateral bending loads whereas implants are lesslateral bending loads whereas implants are less
effective.effective.
The elastic modulus of a tooth is closer to boneThe elastic modulus of a tooth is closer to bone
than any of the currently available dentalthan any of the currently available dental
implant biomaterials.implant biomaterials.
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7. Under similar mechanical loading conditions,Under similar mechanical loading conditions,
implants generate greater stresses and strainsimplants generate greater stresses and strains
at the crest of the bone compared with a tooth.at the crest of the bone compared with a tooth.
Natural teeth exhibit reversible signs andNatural teeth exhibit reversible signs and
symptoms of occlusal trauma whereas implantssymptoms of occlusal trauma whereas implants
do not.do not.
The tooth show clinical signs of increasedThe tooth show clinical signs of increased
stress.stress.
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8. Teeth benefit from increased occlusalTeeth benefit from increased occlusal
awareness compared with implants.awareness compared with implants.
Teeth deliver a rapid, sharp pain sensationTeeth deliver a rapid, sharp pain sensation
under high pressure that triggers a protectiveunder high pressure that triggers a protective
mechanismmechanism
Clinical evidence of occlusal trauma on teethClinical evidence of occlusal trauma on teeth
include overall increase in PDL thicknessinclude overall increase in PDL thickness
whereas implant signs are only around thewhereas implant signs are only around the
crestal region.crestal region.
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9. A lateral force on a natural tooth is rapidlyA lateral force on a natural tooth is rapidly
dissipated away from the crest of the bonedissipated away from the crest of the bone
toward the apex of the tooth and pivots 2/3rdstoward the apex of the tooth and pivots 2/3rds
turn toward the tapered apex with a lateral load.turn toward the tapered apex with a lateral load.
The natural tooth, with its modulus of elasticityThe natural tooth, with its modulus of elasticity
similar to bone, periodontal ligament, andsimilar to bone, periodontal ligament, and
unique cross sections and dimensionsunique cross sections and dimensions
constitutes a near perfect optimization systemconstitutes a near perfect optimization system
to handle stress.to handle stress.
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10. Occlusion on Natural Teeth andOcclusion on Natural Teeth and
ImplantsImplants
In the implant tooth fixed prostheses, fourIn the implant tooth fixed prostheses, four
important components contributeimportant components contribute
movement to the systemmovement to the system
1. the implant1. the implant
2. bone2. bone
3. tooth and3. tooth and
4. prosthesis4. prosthesis
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11. Because of initial difference in verticalBecause of initial difference in vertical
movement of teeth and implants in the samemovement of teeth and implants in the same
arch, the initial occlusal contacts shouldarch, the initial occlusal contacts should
account for this difference,or the implant willaccount for this difference,or the implant will
sustain greater loads than the adjacent teeth.sustain greater loads than the adjacent teeth.
The implant should barely contact and theThe implant should barely contact and the
adjacent teeth should exhibit greater initialadjacent teeth should exhibit greater initial
contactscontacts
Only axial occlusal contacts should be presentOnly axial occlusal contacts should be present
on the implant crown.on the implant crown.
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12. To harmonize the occlusal forces b/w implantsTo harmonize the occlusal forces b/w implants
and teeth, a heavy bite force occlusaland teeth, a heavy bite force occlusal
adjustments is used.adjustments is used.
All lateral excursions of IPO opposing fixedAll lateral excursions of IPO opposing fixed
prosthesis or natural teeth should disoccludeprosthesis or natural teeth should disocclude
the posterior components. The resultant lateralthe posterior components. The resultant lateral
forces are thus distributed only to the anteriorforces are thus distributed only to the anterior
segments of the jaws, resulting in a decrease insegments of the jaws, resulting in a decrease in
overall occlusal force.overall occlusal force.
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13. If anterior implants must disocclude the posteriorIf anterior implants must disocclude the posterior
teeth in excursion, two or more implants splintedteeth in excursion, two or more implants splinted
together should help to dissipate the lateral forces.together should help to dissipate the lateral forces.
Light force and thin articulating paper are first used toLight force and thin articulating paper are first used to
ensure that no implant crown contact occurs duringensure that no implant crown contact occurs during
the initial occlusal or lateral movement of the teeth.the initial occlusal or lateral movement of the teeth.
A heavier force during centric occlusion andA heavier force during centric occlusion and
excursions is then used to develop similar occlusalexcursions is then used to develop similar occlusal
contacts on both anterior implants and natural teeth.contacts on both anterior implants and natural teeth.
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14. Implant Orientation and Influence ofImplant Orientation and Influence of
Load DirectionLoad Direction
Implants are designed for a long axis load toImplants are designed for a long axis load to
the implant body.the implant body.
The greater the angle of the load to the implantThe greater the angle of the load to the implant
long axis, the greater the compressive, tensilelong axis, the greater the compressive, tensile
and shear stresses.and shear stresses.
Not only is the ‘amount’ of stress increased withNot only is the ‘amount’ of stress increased with
angled load, but the ‘type’ of stress converts toangled load, but the ‘type’ of stress converts to
more dangerous shear component.more dangerous shear component.www.indiandentalacademy.comwww.indiandentalacademy.com
16. Bone Mechanics and OcclusionBone Mechanics and Occlusion
‘‘Anisotropy’ refers to the character of theAnisotropy’ refers to the character of the
bone, whereby its mechanical properties,bone, whereby its mechanical properties,
including ultimate strength, depend on theincluding ultimate strength, depend on the
direction in which the bone is loaded.direction in which the bone is loaded.
Cortical bone of human long bones hasCortical bone of human long bones has
been reported as strongest inbeen reported as strongest in
compression, 30% weaker in tension, andcompression, 30% weaker in tension, and
65% weaker in shear.65% weaker in shear.
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18. The IPO attempts to eliminate lateral loads toThe IPO attempts to eliminate lateral loads to
an implant supported prostheses because thean implant supported prostheses because the
magnitude of the force increases and strengthmagnitude of the force increases and strength
of the bone decreases.of the bone decreases.
When these loads cannot be eliminated, aWhen these loads cannot be eliminated, a
reduction in the force magnitude or additionalreduction in the force magnitude or additional
surface area of implant support is indicated tosurface area of implant support is indicated to
reduce the risk of bone loss or implantreduce the risk of bone loss or implant
component fracture.component fracture.
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19. Premature occlusal contacts result in localizedPremature occlusal contacts result in localized
lateral loading of the opposing contactinglateral loading of the opposing contacting
crowns.crowns.
Occlusal evaluation and adjustment in partiallyOcclusal evaluation and adjustment in partially
edentulous implant patients are more importantedentulous implant patients are more important
than in natural dentition.than in natural dentition.
The premature occlusal contact on a toothThe premature occlusal contact on a tooth
corresponds to less initial occlusal force andcorresponds to less initial occlusal force and
often modifies the closure of the mandible,often modifies the closure of the mandible,
resulting in a centric occlusion different fromresulting in a centric occlusion different from
centric relation occlusion.centric relation occlusion.www.indiandentalacademy.comwww.indiandentalacademy.com
20. Once the natural teeth are removed, the boneOnce the natural teeth are removed, the bone
remodels to the height at or below the lowestremodels to the height at or below the lowest
level of the lateral cortical plates.level of the lateral cortical plates.
The greater the crown height, the greater theThe greater the crown height, the greater the
resulting crestal moment with any lateralresulting crestal moment with any lateral
component of force that develops as acomponent of force that develops as a
consequence of an angled load.consequence of an angled load.
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21. IPO aims at reducing the force of occlusalIPO aims at reducing the force of occlusal
contacts, increasing implant number,contacts, increasing implant number,
and/or increasing implant diameter forand/or increasing implant diameter for
implants subjected to angled loads or withimplants subjected to angled loads or with
an increased crown height or on thean increased crown height or on the
cantilever portion of a prosthesis.cantilever portion of a prosthesis.
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22. OCCLUSAL SCHEMESOCCLUSAL SCHEMES
The primary goal of an occlusal scheme isThe primary goal of an occlusal scheme is
to maintain the occlusal load that hasto maintain the occlusal load that has
been transferred to the implant body withinbeen transferred to the implant body within
physiologic limits of each patient .physiologic limits of each patient .
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23. The forces generated by a patient areThe forces generated by a patient are
influenced by :influenced by :
ParafunctionParafunction
Masticatory DynamicsMasticatory Dynamics
Tongue SizeTongue Size
Implant arch position and locationImplant arch position and location
Implant arch form and crown heightImplant arch form and crown height
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24. IMPLANT PROTECTIVEIMPLANT PROTECTIVE
OCCLUSIONOCCLUSION
The concept of “Medial positionedThe concept of “Medial positioned
lingualized occlusion” apply to fixedlingualized occlusion” apply to fixed
implant supported restorations.implant supported restorations.
The maxillary permucosal implant siteThe maxillary permucosal implant site
gradually shifts toward the midline as thegradually shifts toward the midline as the
ridge resorbs.ridge resorbs.
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26. OCCLUSAL TABLE WIDTHOCCLUSAL TABLE WIDTH
In IPO, “the width of the occlusal table isIn IPO, “the width of the occlusal table is
directly related to the width of the implantdirectly related to the width of the implant
body.”body.”
A wide occlusal table favors offsetA wide occlusal table favors offset
contacts during mastication orcontacts during mastication or
parafunctionparafunction
During mastication , the amount of forceDuring mastication , the amount of force
used to penetrate the food bolus is relatedused to penetrate the food bolus is related
to the occlusal table width.to the occlusal table width.
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27. The wider the occlusal table, the greater theThe wider the occlusal table, the greater the
force developed by the biologic system toforce developed by the biologic system to
penetrate the bolus of food.penetrate the bolus of food.
The narrow occlusal table facilitates dailyThe narrow occlusal table facilitates daily
homecare and improves axial loading.homecare and improves axial loading.
The narrower occlusal contour also reduces theThe narrower occlusal contour also reduces the
risk of porcelain fracture.risk of porcelain fracture.
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28. The restorations mimicking the occlusalThe restorations mimicking the occlusal
anatomy of natural teeth often result in offsetanatomy of natural teeth often result in offset
loads (increased stress), complicated homeloads (increased stress), complicated home
care, and increased risk of porcelain fracture.care, and increased risk of porcelain fracture.
As a result , in nonesthetic regions of the mouth,As a result , in nonesthetic regions of the mouth,
the occlusal table should be reduced in widththe occlusal table should be reduced in width
compared with natural teeth.compared with natural teeth.
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29. CROWN CONTOURCROWN CONTOUR
DIVISION – A - BONEDIVISION – A - BONE
Implant can be placed in a more idealImplant can be placed in a more ideal
position for occlusion and esthetics.position for occlusion and esthetics.
In the anterior region, a dicision is madeIn the anterior region, a dicision is made
early in treatment whether an abutment forearly in treatment whether an abutment for
screw retention or for cement retention willscrew retention or for cement retention will
be used in the restoration because itbe used in the restoration because it
affects the position of the implant body.affects the position of the implant body.
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30. Ideally, the implant is located directly underIdeally, the implant is located directly under
the primary occlusal contact and loaded inthe primary occlusal contact and loaded in
an axial direction, thus minimizing thean axial direction, thus minimizing the
effect of offset loads.effect of offset loads.
To load the implant in an axial direction,To load the implant in an axial direction,
the primary occlusal contact shouldthe primary occlusal contact should
therefore be the central fossa region in Divtherefore be the central fossa region in Div
A bone.A bone.
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31. The Div A mandibular implant is placedThe Div A mandibular implant is placed
under the central fossa region of the naturalunder the central fossa region of the natural
tooth.tooth.
When opposing a natural maxillary molar,When opposing a natural maxillary molar,
the primary contacting cusp becomes thethe primary contacting cusp becomes the
maxillary lingual cusp opposing the mand.maxillary lingual cusp opposing the mand.
Implant crown, with the mand. Cusp ofImplant crown, with the mand. Cusp of
decreased height and width over the implantdecreased height and width over the implant
body.body. www.indiandentalacademy.comwww.indiandentalacademy.com
32. The lingual contour of the mand. Implant crown isThe lingual contour of the mand. Implant crown is
similar to the original natural dentition in position,similar to the original natural dentition in position,
and no occlusal contact on the lingual cusp, soand no occlusal contact on the lingual cusp, so
offset loads during parafunction are eliminated.offset loads during parafunction are eliminated.
The posterior maxillry crown is reduced from theThe posterior maxillry crown is reduced from the
lingual aspect, compared with a natural maxillarylingual aspect, compared with a natural maxillary
molar, to reduce the occlusal table width.molar, to reduce the occlusal table width.
When opposing max.implants, the buccal cusps ofWhen opposing max.implants, the buccal cusps of
natural mand.teeth(or crowns on implants) shouldnatural mand.teeth(or crowns on implants) should
be recontoured to minimize offset loads in centricbe recontoured to minimize offset loads in centric
relation occlusion.relation occlusion.
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35. In the posterior esthetic regions of maxilla aIn the posterior esthetic regions of maxilla a
larger diameter implant may be placed thatlarger diameter implant may be placed that
permits restoration of the buccal contours.permits restoration of the buccal contours.
Posterior implants opposing eachother, thePosterior implants opposing eachother, the
facial cusps of max. crowns is required forfacial cusps of max. crowns is required for
esthetics.esthetics.
The other contours of opposing crowns areThe other contours of opposing crowns are
reduced in width to minimize the occlusal tablereduced in width to minimize the occlusal table
width and axially load the implantswidth and axially load the implants
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36. CROWN CONTOURCROWN CONTOUR
DIVISION – B - BONEDIVISION – B - BONE
Div B bone has maxillary and mandibularDiv B bone has maxillary and mandibular
implants positioned under lingual cusp whenimplants positioned under lingual cusp when
compared with the original natural tooth position.compared with the original natural tooth position.
The medially positioned Div B mandibularThe medially positioned Div B mandibular
implant crown central fossa is more lingual thanimplant crown central fossa is more lingual than
the original position.the original position.
A Div B max.implant is often placed under theA Div B max.implant is often placed under the
palatal cusp region of the original natural tooth.palatal cusp region of the original natural tooth.
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38. Bone augmentation for larger implant width isBone augmentation for larger implant width is
more indicated in the maxilla because of themore indicated in the maxilla because of the
less dense bone and the prosthetic needs toless dense bone and the prosthetic needs to
replace an esthetic buccal crown contour.replace an esthetic buccal crown contour.
The weakest implant in bone density, width orThe weakest implant in bone density, width or
prostheses type determines the axial load.prostheses type determines the axial load.
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39. Influence of Surface AreaInfluence of Surface Area
Mechanical stress = defined as the forceMechanical stress = defined as the force
magnitude divided by the cross sectional areamagnitude divided by the cross sectional area
over which that force is applied.over which that force is applied.
When forces are increased in magnitude,When forces are increased in magnitude,
direction, or duration, ridge augmentation maydirection, or duration, ridge augmentation may
be required to improve implant placement,be required to improve implant placement,
reduce crown height, and increase implant widthreduce crown height, and increase implant width
and number to compensate for the increasedand number to compensate for the increased
loads.loads.
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40. The mechanical stress at the crest is reducedThe mechanical stress at the crest is reduced
with wider implants compared with narrowwith wider implants compared with narrow
ones.ones.
Unavoidable, less ideal implant orientationsUnavoidable, less ideal implant orientations
should be accommodated through adjustmentsshould be accommodated through adjustments
in occlusion.in occlusion.
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41. Design to the Weakest ArchDesign to the Weakest Arch
All treatment planning decsions for IPO should beAll treatment planning decsions for IPO should be
based on careful consideration ofbased on careful consideration of
1. Identifying the weakest link in the overall1. Identifying the weakest link in the overall
restorationrestoration
2. Establishing occlusal and prosthetic2. Establishing occlusal and prosthetic
schemes to protect that component ofschemes to protect that component of
the structure.the structure.
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42. Stress relieving components reduce impact loads toStress relieving components reduce impact loads to
the implant support.the implant support.
The most common implant treatment, a traditional softThe most common implant treatment, a traditional soft
tissue supported complete denture, is a maxillarytissue supported complete denture, is a maxillary
denture opposing a mandibular implant supporteddenture opposing a mandibular implant supported
restoration.restoration.
Reduced occlusal forces with an absence of lateralReduced occlusal forces with an absence of lateral
contacts in excursions are recommended on posteriorcontacts in excursions are recommended on posterior
cantilevers or anterior offset pontics.cantilevers or anterior offset pontics.www.indiandentalacademy.comwww.indiandentalacademy.com
43. Full Arch Fixed ProsthesisFull Arch Fixed Prosthesis
Fixed prostheses on natural teeth opposingFixed prostheses on natural teeth opposing
FP -1 to RP -1 implant restorations shouldFP -1 to RP -1 implant restorations should
follow mutually protected occlusal shemes.follow mutually protected occlusal shemes.
In protrusion, there should be total absence ofIn protrusion, there should be total absence of
posterior contacts.posterior contacts.
Two or more implants should share any lateralTwo or more implants should share any lateral
force, and lateral excursions should occur asforce, and lateral excursions should occur as
far forward as is practical and include thefar forward as is practical and include thewww.indiandentalacademy.comwww.indiandentalacademy.com
44. Occlusal MaterialsOcclusal Materials
The materials selected for the occlusalThe materials selected for the occlusal
surface of the prostheses affect thesurface of the prostheses affect the
transmission of forces and thetransmission of forces and the
maintenance of occlusal contacts.maintenance of occlusal contacts.
The three most common groups ofThe three most common groups of
occlusal materials areocclusal materials are porcelain, acrylicporcelain, acrylic
and metal.and metal.
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45. Occlusal materials are evaluated byOcclusal materials are evaluated by
following criterias:following criterias:
EstheticsEsthetics
Impact ForceImpact Force
A Static LoadA Static Load
Chewing EfficiencyChewing Efficiency
FractureFracture
WearWear
Inter arch Space RequirementsInter arch Space Requirements
Accuracy of CastingAccuracy of Castingwww.indiandentalacademy.comwww.indiandentalacademy.com
46. EstheticsEsthetics
Porcelain – Most estheticPorcelain – Most esthetic
Acrylic – AcceptableAcrylic – Acceptable
Metal – Is a poor ChoiceMetal – Is a poor Choice
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47. ForcesForces
The hardness of a material is related to itsThe hardness of a material is related to its
ability to absorb stress from impact loads.ability to absorb stress from impact loads.
Enamel has a hardnes of 350 kg/mm2Enamel has a hardnes of 350 kg/mm2
Porcelain – 2.5 times greater than enamelPorcelain – 2.5 times greater than enamel
Composit - 85% that of enamelComposit - 85% that of enamel
Acrylic – 17kg/mm2Acrylic – 17kg/mm2
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48. Chewing EfficiencyChewing Efficiency
Fixed prostheses exhibit an improvedFixed prostheses exhibit an improved
efficiency compared with removable softefficiency compared with removable soft
tissue – borne prostheses, regardless oftissue – borne prostheses, regardless of
the occlusal material.the occlusal material.
Shultz – Acrylic was 30% less efficientShultz – Acrylic was 30% less efficient
than porcelain/metal whereas there wasthan porcelain/metal whereas there was
no difference b/w gold and porcelainno difference b/w gold and porcelain
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49. WearWear
Definition – Wear is the deterioration,Definition – Wear is the deterioration,
change,or loss of a surface caused bychange,or loss of a surface caused by
use.use.
Dramatic changes in occlusal contacts inDramatic changes in occlusal contacts in
centric relation and excursions, occlusalcentric relation and excursions, occlusal
vertical dimension, and esthetics mayvertical dimension, and esthetics may
occur as a consequence of significantoccur as a consequence of significant
occlusal wear.occlusal wear.
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50. The factors affecting the amount of wearThe factors affecting the amount of wear
include:include:
MagnitudeMagnitude
DurationDuration
AngleAngle
SpeedSpeed
HardnessHardness
TemperatureTemperature
Surface force of opposing forceSurface force of opposing force
Chemical natureChemical nature
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51. The wear rate of occlusal materials, especiallyThe wear rate of occlusal materials, especially
in the partially edentulous patients within the partially edentulous patients with
unrestored teeth, should be simolar to enamel.unrestored teeth, should be simolar to enamel.
Adhesive wear occurs when one hard surfaceAdhesive wear occurs when one hard surface
slides over a surface of lesser hardness. (goldslides over a surface of lesser hardness. (gold
occlusals)occlusals)
Porcelain in esthetic regions opposing gold inPorcelain in esthetic regions opposing gold in
the more nonesthetic areas or metal occlusalsthe more nonesthetic areas or metal occlusals
in both arches when parafunction or marginalin both arches when parafunction or marginal
interarch space is present are the materialsinterarch space is present are the materials
most often selected as implant occlusalmost often selected as implant occlusal
materials.materials. www.indiandentalacademy.comwww.indiandentalacademy.com
52. Material FractureMaterial Fracture
Acrylic or composite materials fracture moreAcrylic or composite materials fracture more
easily.easily.
Compressive strength of enamel is 40,000psi.Compressive strength of enamel is 40,000psi.
Metal occlusals donot easily fracture, provideMetal occlusals donot easily fracture, provide
good wear resisatance, and have minimumgood wear resisatance, and have minimum
impact load compared with porcelain.impact load compared with porcelain.
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53. AccuracyAccuracy
Metal shrinkage is 10 times less than porcelainMetal shrinkage is 10 times less than porcelain
or acrylic and therefore permits the fabrication ofor acrylic and therefore permits the fabrication of
a more passive casting, as with screw retaineda more passive casting, as with screw retained
restorations, the occlusal material may make arestorations, the occlusal material may make a
significant difference.significant difference.
This is most important in regions of long spansThis is most important in regions of long spans
and/or with a large volume of material.and/or with a large volume of material.
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54. Interarch SpaceInterarch Space
Acrylic restorations receive their strength fromAcrylic restorations receive their strength from
bulk and therefore require greater interarchbulk and therefore require greater interarch
space.space.
Metal occlusals require the least amount ofMetal occlusals require the least amount of
space.space.
Esthetics is best satisfied with porcelain, whichEsthetics is best satisfied with porcelain, which
has improved properties compared with acrylichas improved properties compared with acrylic
concerning fractures and retention.concerning fractures and retention.
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55. CONCLUSIONCONCLUSION
The local occlusal considerations in implant dentistryThe local occlusal considerations in implant dentistry
include the transoteal forces, bone biomechanics,include the transoteal forces, bone biomechanics,
basic biomechanics, differences in natural teeth andbasic biomechanics, differences in natural teeth and
implants, muscles of mastication and occlusal force,implants, muscles of mastication and occlusal force,
and bone resorption.and bone resorption.
The incorporation of all these factors lead to anThe incorporation of all these factors lead to an
occlusal scheme (IPO) and it is a consistent approachocclusal scheme (IPO) and it is a consistent approach
for implant occlusal schemes.for implant occlusal schemes.
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56. Thank you
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