Mouth preparation for removable partial denture/ dental education in india

MOUTH PREPARATIONMOUTH PREPARATION
FOR REMOVABLEFOR REMOVABLE
PARTIAL DENTUREPARTIAL DENTURE
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com
www.indiandentalacademy.comwww.indiandentalacademy.com

CONTENTSCONTENTS
 IntroductionIntroduction
 DefinitionsDefinitions
 Objectives of mouth preparation inObjectives of mouth preparation in
removable partial dentureremovable partial denture
 Mouth preparation:Mouth preparation:
 Relief of pain and infectionRelief of pain and infection
 Oral surgical proceduresOral surgical procedures

 Conditioning of abused and irritated tissueConditioning of abused and irritated tissue
 Periodontal therapy:Periodontal therapy:
o Oral hygiene instructionsOral hygiene instructions
o Scaling & root planningScaling & root planning
o Provision of support for weakened teethProvision of support for weakened teeth
 Correction of occlusal planeCorrection of occlusal plane
 Correction of malalignmentCorrection of malalignment

 Abutment teeth preparation:Abutment teeth preparation:
o Reshaping teethReshaping teeth
o Preparation of retentive areas for claspsPreparation of retentive areas for clasps
in enamelin enamel
o Inlays, onlays and crownsInlays, onlays and crowns
o Occlusal rest seat preparationOcclusal rest seat preparation
o Rest seat preparation of anterior teethRest seat preparation of anterior teeth

 Review of literatureReview of literature
 SummarySummary
 ConclusionConclusion
 ReferencesReferences

INTRODUCTIONINTRODUCTION

 Mouth preparation is fundamental to aMouth preparation is fundamental to a
successful removable partial denturesuccessful removable partial denture
prosthesis.prosthesis.
 It contributes to the philosophy: theIt contributes to the philosophy: the
prescribed prosthesis must not onlyprescribed prosthesis must not only
replace what is missing, but also preservereplace what is missing, but also preserve
the remaining tissue & structures that willthe remaining tissue & structures that will
enhance the prosthesis.enhance the prosthesis.

 Mouth preparation follows in logicalMouth preparation follows in logical
sequence after oral diagnosis and tentativesequence after oral diagnosis and tentative
treatment planning.treatment planning.
 Final treatment planning may be deferredFinal treatment planning may be deferred
till the response to preparatory procedurestill the response to preparatory procedures
can be ascertained.can be ascertained.

 The extent of mouth preparation & theThe extent of mouth preparation & the
various procedures involved varies fromvarious procedures involved varies from
person to person.person to person.
 Some patients might require minimalSome patients might require minimal
mouth preparation involving removal ofmouth preparation involving removal of
interferences & preparation of rest seats.interferences & preparation of rest seats.
 However a majority of the patients mightHowever a majority of the patients might
require extensive treatment.require extensive treatment.

 It includes correction of occlusal plane,It includes correction of occlusal plane,
oral surgical preparation like extraction oforal surgical preparation like extraction of
non-restorable teeth, removal of tori ornon-restorable teeth, removal of tori or
exostosis & preprosthetic surgeries.exostosis & preprosthetic surgeries.
 Periodontal preparation including oralPeriodontal preparation including oral
prophylaxis, treatment of periodontalprophylaxis, treatment of periodontal
abcess etc. Also changes in gingivalabcess etc. Also changes in gingival
contour following periodontal treatmentcontour following periodontal treatment
should be complete before workingshould be complete before working
impressions are obtained.impressions are obtained.

 Orthodontic treatment, so that any requiredOrthodontic treatment, so that any required
improvement in the position of the teeth canimprovement in the position of the teeth can
be achieved without delaying the prostheticbe achieved without delaying the prosthetic
treatment unduly.treatment unduly.
 Restorative treatment & root canal therapyRestorative treatment & root canal therapy
to ensure that the remaining teeth are in ato ensure that the remaining teeth are in a
healthy state and preparation of abutmenthealthy state and preparation of abutment
teeth so that the crown shape of theteeth so that the crown shape of the
remaining teeth is improved to receiveremaining teeth is improved to receive
rests, retentive clasp arms, bracing &rests, retentive clasp arms, bracing &
reciprocating elements.reciprocating elements.

DEFINITIONSDEFINITIONS

GUIDING PLANESGUIDING PLANES (GPT 8) :(GPT 8) :
Vertically parallel surfaces on abutment
teeth or/and dental implant abutments
oriented so as to contribute to the
direction of the path of placement and
removal of a removable dental
prosthesis

INTERFERENCESINTERFERENCES (GPT 8):(GPT 8):
In dentistry, any tooth contacts that
interfere with or hinder harmonious
mandibular movement

PATH OF INSERTIONPATH OF INSERTION (GPT 8) :(GPT 8) :
The specific direction in which a
prosthesis is placed on the abutment
teeth or dental implant(s)

SURVEY LINESURVEY LINE (GPT 8) :(GPT 8) :
A line produced on a cast by a surveyor
marking the greatest prominence of
contour in relation to the planned path
of placement of a restoration

ENEMELOPLASTY / OCCLUSALENEMELOPLASTY / OCCLUSAL
RESHAPINGRESHAPING (GPT 8) :(GPT 8) :
The intentional alteration of the occlusal
surfaces of teeth to change their form

OBJECTIVES OF MOUTHOBJECTIVES OF MOUTH
PREPARATION IN REMOVABLEPREPARATION IN REMOVABLE
PARTIAL DENTUREPARTIAL DENTURE
1.To establish a state of health in the1.To establish a state of health in the
supporting & contiguous tissues.supporting & contiguous tissues.
2.To eliminate interferences or obstructions2.To eliminate interferences or obstructions
to the placement, removal, & function of theto the placement, removal, & function of the

3. To establish an acceptable occlusal3. To establish an acceptable occlusal
scheme.scheme.
4. To establish an acceptable occlusal plane.4. To establish an acceptable occlusal plane.
5. To alter natural tooth form to5. To alter natural tooth form to
accommodate the requirements of form &accommodate the requirements of form &
function of the prosthesis.function of the prosthesis.

Planning the mouth preparationsPlanning the mouth preparations
 When a removable partial denture isWhen a removable partial denture is
preferred choice of treatment, an orderly,preferred choice of treatment, an orderly,
sequential plan of action should be thought ofsequential plan of action should be thought of
that should include:that should include:

1.1. A thorough examination of the patientA thorough examination of the patient
includingincluding
 Patient’s medical & dentalPatient’s medical & dental
historyhistory::
The prognosis of a removable partialThe prognosis of a removable partial
denture based on the health of thedenture based on the health of the
patient is less complicated when healthpatient is less complicated when health
is a considered in 3 classesis a considered in 3 classes

• TheThe 11stst
classclass patient is in good health, haspatient is in good health, has
healthy mucosa & lack of tooth mobility,healthy mucosa & lack of tooth mobility,
even in the presence of occlusaleven in the presence of occlusal
disharmonies.disharmonies.
• The caries incidence is low or no history ofThe caries incidence is low or no history of
caries is present.caries is present.
• The properly designed restoration for thisThe properly designed restoration for this
patient should not only provide years ofpatient should not only provide years of
masticatory function, but should providemasticatory function, but should provide
preventive service.preventive service.

• TheThe class2class2 patient is in average health & haspatient is in average health & has
health assets & disease liabilities that canhealth assets & disease liabilities that can
either be corrected or eliminated.either be corrected or eliminated.
• Usually demonstrates past or present caries.Usually demonstrates past or present caries.
• Gingivitis or periodontal pockets that can beGingivitis or periodontal pockets that can be
eradicated are present from the occlusaleradicated are present from the occlusal
imbalance caused by loss of teeth.imbalance caused by loss of teeth.
• Successful treatment depends on theSuccessful treatment depends on the
patient’s cooperation in personal oralpatient’s cooperation in personal oral
hygiene, periodontal stimulation, & prompthygiene, periodontal stimulation, & prompt
return for maintenance.return for maintenance.

• TheThe class 3class 3 patients are a poor risk with apatients are a poor risk with a
history of predisposition to systemichistory of predisposition to systemic
disease.disease.
• Correction or elimination of the liability isCorrection or elimination of the liability is
uncertain.uncertain.
• Recurrent caries or periodontal pocketsRecurrent caries or periodontal pockets
develop in spite of the best efforts ofdevelop in spite of the best efforts of
previous,competent,professional care.previous,competent,professional care.

 Digital & visual examination:Digital & visual examination:
• Search for tissues intolerant to stress, whichSearch for tissues intolerant to stress, which
must be corrected to ensure success.must be corrected to ensure success.
• Attention is directed to caries, erosion,Attention is directed to caries, erosion,
abrasion, loose teeth, inflamed hypertrophicabrasion, loose teeth, inflamed hypertrophic
or ulcerated mucosa, knife-edge oror ulcerated mucosa, knife-edge or
unhealed ridges, & tori that interfere withunhealed ridges, & tori that interfere with
lingual bar placement.lingual bar placement.

 Radiographs of teeth & edentulousRadiographs of teeth & edentulous
spaces:spaces:
• The alveolar & supporting tissues mayThe alveolar & supporting tissues may
reveal evidence of previous trauma that notreveal evidence of previous trauma that not
only precludes the possibility of using theonly precludes the possibility of using the
adjacent tooth for an abutment, but alsoadjacent tooth for an abutment, but also
may indicate its removal to restore amay indicate its removal to restore a
healthy foundation.healthy foundation.
• The combined force of occlusion and theThe combined force of occlusion and the
clasps, must be correlated to the alveolarclasps, must be correlated to the alveolar
support of the abutment teeth.support of the abutment teeth.

• Splinting the abutments when there is aSplinting the abutments when there is a
doubt concerning their future stability isdoubt concerning their future stability is
advised.advised.
• The elimination of sequestra, rootThe elimination of sequestra, root
fragments & residual infections makes thefragments & residual infections makes the
patients adjustment less complicated.patients adjustment less complicated.
• Eliminating foci of infection aids inEliminating foci of infection aids in
restoring the patient to the healthrestoring the patient to the health
optimum to facilitation of the retention ofoptimum to facilitation of the retention of
the remaining natural teeth.the remaining natural teeth.

 Surveyed & occluded study casts:Surveyed & occluded study casts:
• Surveyed study casts mounted on anSurveyed study casts mounted on an
articulator provide an opportunity toarticulator provide an opportunity to
preview the location of the metalpreview the location of the metal
framework.framework.
• Changes & improvements of design on theChanges & improvements of design on the
study cast arte the least expensive to make.study cast arte the least expensive to make.

MOUTH PREPARATIONMOUTH PREPARATION

 Dental conditions causing pain orDental conditions causing pain or
discomfort due to caries or defectivediscomfort due to caries or defective
restoration should be treated as early inrestoration should be treated as early in
the treatment process as possible tothe treatment process as possible to
eliminate the possibility of an acuteeliminate the possibility of an acute
episode or pain occurring during theepisode or pain occurring during the
treatment procedure.treatment procedure.
RELIEF OF PAINRELIEF OF PAIN

 The gingival tissue should also be treatedThe gingival tissue should also be treated
early to decrease the possibility ofearly to decrease the possibility of
periodontal abscesses and otherperiodontal abscesses and other
inflammatory responses.inflammatory responses.
 Calculus accumulation should be derided,Calculus accumulation should be derided,
plaque should be controlled and aplaque should be controlled and a
preventive dental hygiene program shouldpreventive dental hygiene program should
be started and vigorously monitored.be started and vigorously monitored.

ORAL SURGICAL PREPARATIONORAL SURGICAL PREPARATION
 All Preprosthetic surgical treatment forAll Preprosthetic surgical treatment for
the RPD patient should be completed asthe RPD patient should be completed as
soon as possible.soon as possible.
 Generally includes manipulation of bothGenerally includes manipulation of both
hard & soft tissues which introduces thehard & soft tissues which introduces the
necessity of adequate healing time beforenecessity of adequate healing time before
the fabrication of the prosthesis.the fabrication of the prosthesis.

 The longer the time interval between theThe longer the time interval between the
surgery and the impression procedures,surgery and the impression procedures,
the more complete the healing andthe more complete the healing and
consequently the more stable the dentureconsequently the more stable the denture
bearing areas.bearing areas.
 Necessary endodontic surgery,Necessary endodontic surgery,
periodontal surgery and oral surgeryperiodontal surgery and oral surgery
should be planned so that they can beshould be planned so that they can be
completed during the same time frame.completed during the same time frame.

ExtractionsExtractions
 The extraction of non-strategic teeth thatThe extraction of non-strategic teeth that
would present complications or those thatwould present complications or those that
might be detrimental to the design of themight be detrimental to the design of the
prosthesis is necessary.prosthesis is necessary.

 Planned extractions should be done afterPlanned extractions should be done after
careful evaluation of each remaining tooth.careful evaluation of each remaining tooth.
 Each tooth should be evaluated for strategicEach tooth should be evaluated for strategic
position & potential contribution to theposition & potential contribution to the
success of the prosthesissuccess of the prosthesis

Removal of residual rootsRemoval of residual roots
 Generally all retainedGenerally all retained
roots or rootroots or root
fragments should befragments should be
removed, especially, ifremoved, especially, if
they are in closethey are in close
proximity to the tissueproximity to the tissue
surface or if there issurface or if there is
evidence of associatedevidence of associated
pathological findings.pathological findings.

 Residual roots adjacent to abutment teethResidual roots adjacent to abutment teeth
may contribute to the progression ofmay contribute to the progression of
periodontal pockets & compromise theperiodontal pockets & compromise the
results from subsequent periodontalresults from subsequent periodontal
therapy.therapy.
 The removal of root tips can beThe removal of root tips can be
accomplished from facial or palatalaccomplished from facial or palatal
surfaces without resulting in a reduction ofsurfaces without resulting in a reduction of
alveolar ridge height or endangeringalveolar ridge height or endangering
adjacent teeth.adjacent teeth.

Impacted teethImpacted teeth
 All impacted teeth,All impacted teeth,
including those inincluding those in
edentulous areas &edentulous areas &
those adjacent tothose adjacent to
abutment teeth, shouldabutment teeth, should
be considered forbe considered for
removal.removal.

 The periodontal implications of impactedThe periodontal implications of impacted
teeth adjacent to abutments are similar toteeth adjacent to abutments are similar to
those for retained roots.those for retained roots.
 Early elective removal of impactionsEarly elective removal of impactions
prevents later serious acute & chronicprevents later serious acute & chronic
infection with extensive bone loss.infection with extensive bone loss.

 Any impacted teeth that can be reached withAny impacted teeth that can be reached with
a periodontal probe must be removed toa periodontal probe must be removed to
treat the periodontal pocket & prevent moretreat the periodontal pocket & prevent more
extensive damage.extensive damage.

 Asymptomatic impacted teeth in theAsymptomatic impacted teeth in the
elderly, covered with bone & with noelderly, covered with bone & with no
evidence of pathology should be left toevidence of pathology should be left to
preserve the arch morphology.preserve the arch morphology.
 If an impacted tooth is left, it should beIf an impacted tooth is left, it should be
recorded & patient informed of it.recorded & patient informed of it.
 Radiographs should be taken at regularRadiographs should be taken at regular
intervals to ensure that there are nointervals to ensure that there are no
adverse changes.adverse changes.

Malposed teethMalposed teeth
 Loss of individual tooth or group of teethLoss of individual tooth or group of teeth
may lead to extrusion, drifting ormay lead to extrusion, drifting or
combination of malpositioning of thecombination of malpositioning of the
remaining teeth.remaining teeth.
 In most cases, the alveolar boneIn most cases, the alveolar bone
supporting the extruded teeth also will besupporting the extruded teeth also will be
carried occlusally.carried occlusally.

 Orthodontics may help to correct theOrthodontics may help to correct the
occlusal discrepancy.occlusal discrepancy.
 Where it is not practical due to lack ofWhere it is not practical due to lack of
teeth for anchorage of orthodonticteeth for anchorage of orthodontic
appliances, or other reasons, surgicalappliances, or other reasons, surgical
repositioning can be done as an outrepositioning can be done as an out
patient procedure.patient procedure.

Misplaced teethMisplaced teeth
 Teeth that are grosslyTeeth that are grossly
misplaced in the archmisplaced in the arch
should be removed inshould be removed in
the interests of boththe interests of both
function andfunction and
esthetics. Anteriorlyesthetics. Anteriorly
misplaced teeth thatmisplaced teeth that
are unsightly may beare unsightly may be
extracted andextracted and
replaced on thereplaced on the
denture.denture.

 Sometimes cases present where no spaceSometimes cases present where no space
retainer has been inserted after theretainer has been inserted after the
extraction of a central incisor, andextraction of a central incisor, and
closure, up to half the width of the tooth,closure, up to half the width of the tooth,
has occurred. Overlapping the replacinghas occurred. Overlapping the replacing
tooth may give a reasonable appearancetooth may give a reasonable appearance
but often the most satisfactory result isbut often the most satisfactory result is
achieved by extraction of one of theachieved by extraction of one of the
contiguous teeth.contiguous teeth.

Lower posterior teeth with gross lingualLower posterior teeth with gross lingual
inclination may prevent the correct positioninginclination may prevent the correct positioning
of a bar and, therefore, warrant extraction. Aof a bar and, therefore, warrant extraction. A
posterior tooth or teeth which have over-posterior tooth or teeth which have over-
erupted into a space created by the extractionerupted into a space created by the extraction
of their opponents may interfere withof their opponents may interfere with
occlusion. When this displacement is moreocclusion. When this displacement is more
than slight and cannot be corrected bythan slight and cannot be corrected by
grinding, extraction is often necessary .grinding, extraction is often necessary .

Sometimes a lower molarSometimes a lower molar
is found impinging uponis found impinging upon
the tuberosity/upperthe tuberosity/upper
impinging retromolar padimpinging retromolar pad
rendering the denturerendering the denture
impossible unless theimpossible unless the
vertical dimension isvertical dimension is
increased, if this is notincreased, if this is not
indicated the offendingindicated the offending
tooth should be extractedtooth should be extracted
or surgical reduction of theor surgical reduction of the
lower tooth for supportlower tooth for support
and retention.and retention.

Cysts & odontogenic tumorsCysts & odontogenic tumors

 Panoramic roentgenograms of the jaws arePanoramic roentgenograms of the jaws are
recommended to survey for unsuspectedrecommended to survey for unsuspected
pathological conditions.pathological conditions.
 When present, a periapical radiographWhen present, a periapical radiograph
should be taken to confirm or deny theshould be taken to confirm or deny the
presence of the lesion .presence of the lesion .
 All radiolucenceis & radio-opacities observedAll radiolucenceis & radio-opacities observed
in the jaws should be investigated and thein the jaws should be investigated and the
diagnosis confirmed.diagnosis confirmed.

 The patient should be informed of theThe patient should be informed of the
diagnosis & provided with the variousdiagnosis & provided with the various
options for resolution of the abnormality.options for resolution of the abnormality.

Exostoses & toriExostoses & tori
 Presence of exostoses & tori compromise thePresence of exostoses & tori compromise the
design of the RPD.design of the RPD.
 Modification of denture design at times canModification of denture design at times can
accommodate for exostoses, but moreaccommodate for exostoses, but more
frequently resulting in additional stress tofrequently resulting in additional stress to
the supporting elements & compromisedthe supporting elements & compromised
function.function.

 In addition, the mucosa covering the bonyIn addition, the mucosa covering the bony
protuberances is extremely thin & friable.protuberances is extremely thin & friable.
Thus, the removable partial dentureThus, the removable partial denture
components close to this type of tissuecomponents close to this type of tissue
may cause irritation & chronic ulceration.may cause irritation & chronic ulceration.
 Those approximating the gingivalThose approximating the gingival
margins may complicate maintenance ofmargins may complicate maintenance of
periodontal health & eventually lead toperiodontal health & eventually lead to
loss of strategic abutment teeth.loss of strategic abutment teeth.

 The removal of exostosis & tori is not aThe removal of exostosis & tori is not a
complex procedure & is advantageous tocomplex procedure & is advantageous to
remove them in contrast to the deleteriousremove them in contrast to the deleterious
effects their continued presence can create.effects their continued presence can create.

Hyperplastic tissueHyperplastic tissue
o Often seen in the formOften seen in the form
of fibrous tuberosities,of fibrous tuberosities,
soft flabby ridges, foldssoft flabby ridges, folds
of redundant tissue inof redundant tissue in
the vestibule or floor ofthe vestibule or floor of
the mouth,& palatalthe mouth,& palatal
papillomatosis.papillomatosis.

 All theses forms of excess tissue should beAll theses forms of excess tissue should be
removed to provide a firm base for theremoved to provide a firm base for the
denture.denture.
 This will also produce a more stable denture,This will also produce a more stable denture,
reduce stress & strain on the supportingreduce stress & strain on the supporting
teeth & tissue & in may instances provide ateeth & tissue & in may instances provide a
more favorable orientation of the occlusalmore favorable orientation of the occlusal
plane & arch form for the arrangement ofplane & arch form for the arrangement of
artificial teeth.artificial teeth.

 The surgical procedures should not resultThe surgical procedures should not result
in reduction in the vestibular depthin reduction in the vestibular depth
 The tissues can be removed by the use ofThe tissues can be removed by the use of
scalpel, currette or even electrosurgery orscalpel, currette or even electrosurgery or
laser.laser.
 A surgical stent should always be usedA surgical stent should always be used
after the surgery to provide a moreafter the surgery to provide a more
comfortable healing period.comfortable healing period.

Muscle attachment & frenaMuscle attachment & frena
 Due to the loss of bone height, muscleDue to the loss of bone height, muscle
attachments may insert on or near theattachments may insert on or near the
residual ridge crest.residual ridge crest.
 Mylohyoid, buccinator, mentalis, &Mylohyoid, buccinator, mentalis, &
genioglossus muscles are most likely togenioglossus muscles are most likely to
cause problems of this nature.cause problems of this nature.

 In addition, muscles such as theIn addition, muscles such as the
genioglossus & mentalis often producegenioglossus & mentalis often produce
bony protuberances at their attachment,bony protuberances at their attachment,
that may also result in removable partialthat may also result in removable partial
denture design.denture design.
 Appropriate ridge extension proceduresAppropriate ridge extension procedures
can reposition attachments & removecan reposition attachments & remove
bony spines, which will enhance thebony spines, which will enhance the
comfort & function of the prosthesiscomfort & function of the prosthesis..

 Maxillary labial & mandibular lingualMaxillary labial & mandibular lingual
frenae are most common source offrenae are most common source of
interference, & can be easily modifiedinterference, & can be easily modified
with surgery.with surgery.

Bony spines & knife-edge ridgesBony spines & knife-edge ridges
 Sharp bony spiculesSharp bony spicules
must be removed &must be removed &
knifelike crestsknifelike crests
gently rounded.gently rounded.
 It is very importantIt is very important
to perform theseto perform these
procedures shouldprocedures should
be carried out withbe carried out with
minimum bone loss.minimum bone loss.

 In case the procedure leads to insufficientIn case the procedure leads to insufficient
ridge support, we can consider vestibularridge support, we can consider vestibular
deepening for the correction of deficiencydeepening for the correction of deficiency
or insertion of various graft materials.or insertion of various graft materials.

Polyps, papillomas& traumaticPolyps, papillomas& traumatic
hemangiomashemangiomas
 All abnormal softAll abnormal soft
tissue lesions should betissue lesions should be
excised & submittedexcised & submitted
for pathologicalfor pathological
examination beforeexamination before
the fabrication of thethe fabrication of the

 New or additional stimulation to the areaNew or additional stimulation to the area
introduced by the prosthesis may produceintroduced by the prosthesis may produce
discomfort or even malignant changes indiscomfort or even malignant changes in
the tumor.the tumor.

Hyperkeratoses, erythroplasia, &Hyperkeratoses, erythroplasia, &
ulcerationsulcerations
 All abnormal, white,All abnormal, white,
red, or ulcerative lesionsred, or ulcerative lesions
should be investigated.should be investigated.
 The lesions should beThe lesions should be
removed & healingremoved & healing
accomplished beforeaccomplished before
fabrication of thefabrication of the

 In some cases, the removable prosthesisIn some cases, the removable prosthesis
design will have to be modified to preventdesign will have to be modified to prevent
areas of possible sensitivity, such as afterareas of possible sensitivity, such as after
irradiation treatments or the excoriationirradiation treatments or the excoriation
of erosive lichen planus.of erosive lichen planus.

Dentofacial deformityDentofacial deformity
 Often patients withOften patients with
dentofacial deformitydentofacial deformity
have multiplehave multiple
missing teeth and themissing teeth and the
correction of the jawcorrection of the jaw
deformity candeformity can
simplify the dentalsimplify the dental
rehabilitation.rehabilitation.

 Overall problems faced by the patientOverall problems faced by the patient
should be addressed to before correctingshould be addressed to before correcting
problems related to the dentition.problems related to the dentition.
 Prosthodontist, orthodontist, periodontist,Prosthodontist, orthodontist, periodontist,
oral surgeon & general dentist may playoral surgeon & general dentist may play
a role in the patient’s treatment.a role in the patient’s treatment.
 A sequential treatment plan should beA sequential treatment plan should be
formulated for the patientformulated for the patient

 Surgical correction of jaw deformity canSurgical correction of jaw deformity can
be made in the horizontal, sagittal orbe made in the horizontal, sagittal or
frontal planes.frontal planes.
 Mandible & maxilla may be positionedMandible & maxilla may be positioned
anteriorly or posteriorly & theiranteriorly or posteriorly & their
relationship to the facial planes may berelationship to the facial planes may be
surgically altered to achieve improvedsurgically altered to achieve improved
appearance.appearance.

Augmentation of alveolar boneAugmentation of alveolar bone
 Can be performed with the use ofCan be performed with the use of
autogenous or alloplastic materials.autogenous or alloplastic materials.
 Clinical results depend on carefulClinical results depend on careful
evaluation of the need for augmentation,evaluation of the need for augmentation,
projected volume of required material &projected volume of required material &
site and method of placement.site and method of placement.

CONDITIONING OF ABUSED &CONDITIONING OF ABUSED &
IRRITATED TISSUEIRRITATED TISSUE
 Required in patients often demonstrating theRequired in patients often demonstrating the
following symptoms:following symptoms:
 Inflammation & irritation of mucosa coveringInflammation & irritation of mucosa covering
the denture bearing areas.the denture bearing areas.
 Distortion of normal anatomic structures, suchDistortion of normal anatomic structures, such
as, incisive papilla, rugae and retromolar pads.as, incisive papilla, rugae and retromolar pads.
 Burning sensation in the residual ridge areas,Burning sensation in the residual ridge areas,
tongue and cheeks and lips.tongue and cheeks and lips.

 These conditions are often associated withThese conditions are often associated with
ill-fitting or poorly occluding removableill-fitting or poorly occluding removable
partial dentures.partial dentures.
 Differential diagnosis of these conditionsDifferential diagnosis of these conditions
would include:would include:
 Nutritional deficienciesNutritional deficiencies
 Endocrine imbalancesEndocrine imbalances
 Severe health problems (diabetes or bloodSevere health problems (diabetes or blood
dyscrasias)dyscrasias)
 BruxismBruxism

 These conditions should beforeThese conditions should before
fabricating a new prosthesis or reliningfabricating a new prosthesis or relining
the present denture.the present denture.
 Patient should be informed of the delay inPatient should be informed of the delay in
treatment, till the tissues attain a healthytreatment, till the tissues attain a healthy
state.state.

 A good home care program should beA good home care program should be
introduced that would include:introduced that would include:
 Rinsing mouth thrice daily with prescribedRinsing mouth thrice daily with prescribed
saline solutionsaline solution
 Massaging residual ridge areas, palate &Massaging residual ridge areas, palate &
tongue with soft toothbrushtongue with soft toothbrush
 Removing prosthesis at nightRemoving prosthesis at night
 Using prescribed multivitamin withUsing prescribed multivitamin with
prescribed high protein, low- carbohydrateprescribed high protein, low- carbohydrate
diet.diet.

 Some inflammatory conditions can beSome inflammatory conditions can be
resolved by removing the dentures forresolved by removing the dentures for
extended periods of time.extended periods of time.

Use of tissue conditioningUse of tissue conditioning
materialsmaterials
 Permit distorted tissues to rebound &Permit distorted tissues to rebound &
assume normal form.assume normal form.
 Have a massaging effect on the irritatedHave a massaging effect on the irritated
mucosamucosa
 Occlusal forces are more evenlyOcclusal forces are more evenly
distributed.distributed.

 Maximum benefit of these materials can beMaximum benefit of these materials can be
obtained by :obtained by :
 Eliminating deflective or interferingEliminating deflective or interfering
contacts of old dentures.contacts of old dentures.
 Extending denture bases to proper form toExtending denture bases to proper form to
enhance support, retention & stability.enhance support, retention & stability.
 Relieving tissue side of denture basesRelieving tissue side of denture bases
sufficiently (2mm) to provide space for evensufficiently (2mm) to provide space for even
thickness & distribution of conditioningthickness & distribution of conditioning
material.material.

 Applying material in amounts sufficient toApplying material in amounts sufficient to
provide support & cushioning effect .provide support & cushioning effect .
 Following manufacturer’s directions forFollowing manufacturer’s directions for
manipulation & placement of conditioningmanipulation & placement of conditioning
material.material.

 Conditioning procedure should beConditioning procedure should be
repeated till supporting tissues arerepeated till supporting tissues are
healthy.healthy.
 In cases positive results are not noticed 3-In cases positive results are not noticed 3-
4 weeks, should suspect more serious4 weeks, should suspect more serious
health problems, and should behealth problems, and should be
investigated for.investigated for.

PERIODONTAL PREPARATIONPERIODONTAL PREPARATION
 The periodontal preparation of the mouthThe periodontal preparation of the mouth
usually follows any oral surgical procedureusually follows any oral surgical procedure
and simultaneously with tissue conditioningand simultaneously with tissue conditioning
procedures.procedures.
 Gross debridement is recommended beforeGross debridement is recommended before
procedures such as extraction to preventprocedures such as extraction to prevent
dislodgement of calculus in the extractiondislodgement of calculus in the extraction
socket leading to infection.socket leading to infection.

 Periodontal therapy should be completedPeriodontal therapy should be completed
before restorative procedures, as thebefore restorative procedures, as the
ultimate success of the restorationultimate success of the restoration
depends directly on the health anddepends directly on the health and
integrity of the supporting structures ofintegrity of the supporting structures of
the remaining teeth.the remaining teeth.

 TheThe objectiveobjective is to:is to:
 return the health of the supportingreturn the health of the supporting
structures of the teeth, creating anstructures of the teeth, creating an
environment in which the periodontiumenvironment in which the periodontium
may be maintained.may be maintained.

 Criteria to satisfy the objective are:Criteria to satisfy the objective are:
 Removal & control of all etiological factorsRemoval & control of all etiological factors
contributing to periodontal disease, alongcontributing to periodontal disease, along
with a reduction or elimination of bleedingwith a reduction or elimination of bleeding
on probing.on probing.
 Elimination of, or reduction in, pocketElimination of, or reduction in, pocket
depths of all pockets, with the establishmentdepths of all pockets, with the establishment
of healthy gingival sulci whenever possible.of healthy gingival sulci whenever possible.

 Establishment of functional atraumaticEstablishment of functional atraumatic
occlusal relationships and tooth stability.occlusal relationships and tooth stability.
 Development of a personal plaque controlDevelopment of a personal plaque control
program and definitive maintenanceprogram and definitive maintenance
schedule.schedule.

Periodontal diagnosis andPeriodontal diagnosis and
treatment planningtreatment planning
 The diagnosis is based on a systematic &The diagnosis is based on a systematic &
carefully accomplished examination of thecarefully accomplished examination of the
periodontium.periodontium.

 It includes:It includes:
Health history of the patientHealth history of the patient
Investigation using direct visionInvestigation using direct vision
PalpationPalpation
periodontal probeperiodontal probe
mouth mirrormouth mirror
other auxiliary aids, such as curvedother auxiliary aids, such as curved
explorers, furcation probes, diagnosticexplorers, furcation probes, diagnostic
casts, & appropriate radiographs.casts, & appropriate radiographs.

 It is most important toIt is most important to
carefully explore thecarefully explore the
gingival sulcus &gingival sulcus &
record the probingrecord the probing
pocket depth & sitespocket depth & sites
that bleed on probing.that bleed on probing.

 Normal mobility : 0.05 – 0.1 mmNormal mobility : 0.05 – 0.1 mm
 Grade I mobility : <1mm movement inGrade I mobility : <1mm movement in
buccolingual (B-L)buccolingual (B-L)
directiondirection
 Grade II mobility : 1–2 mm movement in B-LGrade II mobility : 1–2 mm movement in B-L
directiondirection
 Grade III mobility : >2 mm mobility in B-LGrade III mobility : >2 mm mobility in B-L
direction &/or tooth isdirection &/or tooth is
vertically depressible.vertically depressible.
Graded according to ease and extent of tooth movementwww.indiandentalacademy.comwww.indiandentalacademy.com

 Each tooth should be evaluated for mobility,Each tooth should be evaluated for mobility,
which is an indication of the condition of thewhich is an indication of the condition of the
supporting structures, namely thesupporting structures, namely the
periodontium, & is usually caused byperiodontium, & is usually caused by
inflammatory changes in the periodontalinflammatory changes in the periodontal
ligament, traumatic occlusion loss ofligament, traumatic occlusion loss of
attachment, or a combination of the 3attachment, or a combination of the 3
factors.factors.

 In many cases, if the etiological factor canIn many cases, if the etiological factor can
be removed, grade I & II mobile teeth canbe removed, grade I & II mobile teeth can
become stable & may be used successfullybecome stable & may be used successfully
to help support stabilize & retain theto help support stabilize & retain the
 Mobility is not an indication of extraction,Mobility is not an indication of extraction,
unless it cannot aid in support or stabilityunless it cannot aid in support or stability
of the denture or the mobility cannot beof the denture or the mobility cannot be
reduced.reduced.

Treatment planningTreatment planning
 Periodontal treatment planning can bePeriodontal treatment planning can be
usually divided into 3 phases.usually divided into 3 phases.

First phaseFirst phase
(Disease control or Initial therapy)(Disease control or Initial therapy)
 TheThe objectiveobjective is to essentially eliminate oris to essentially eliminate or
reduce local etiological factors before anyreduce local etiological factors before any
periodontal surgical procedures areperiodontal surgical procedures are
accomplished.accomplished.
 It includes:It includes:
 Oral hygiene instructionOral hygiene instruction
 Scaling & root planning & polishingScaling & root planning & polishing
 Occlusal adjustmentOcclusal adjustment
 Temporary splinting if indicated.Temporary splinting if indicated.www.indiandentalacademy.comwww.indiandentalacademy.com

Oral hygiene instructionOral hygiene instruction
 For the oral hygiene routine to beFor the oral hygiene routine to be
successful, the patient must be convincedsuccessful, the patient must be convinced
to follow the prescribed procedureto follow the prescribed procedure
regularly.regularly.
 The most effective motivation techniquesThe most effective motivation techniques
require good understanding by therequire good understanding by the
patient of his/her periodontal condition.patient of his/her periodontal condition.

 Thus, an explanation of the disease, it’sThus, an explanation of the disease, it’s
cause, initiation & progression iscause, initiation & progression is
important.important.
 Instruct patient to use:Instruct patient to use:
 disclosing tablets/wafersdisclosing tablets/wafers
 Soft / medium bristle toothbrushSoft / medium bristle toothbrush
 Unwaxed / waxed dental floss.Unwaxed / waxed dental floss.

 On subsequent visits, oral hygiene can beOn subsequent visits, oral hygiene can be
evaluated & other oral hygiene aids, suchevaluated & other oral hygiene aids, such
as, interdental or sulcular brushesas, interdental or sulcular brushes
incorporated, if needed.incorporated, if needed.
 A satisfactory level of plaque controlA satisfactory level of plaque control
should be achieved.should be achieved.

Scaling & root planningScaling & root planning

 Careful scaling & root planing areCareful scaling & root planing are
fundamental to reestablishment offundamental to reestablishment of
periodontal health.periodontal health.
 Without meticulous removal of calculus,Without meticulous removal of calculus,
plaque & toxic material in the cementumplaque & toxic material in the cementum
other forms of periodontal therapyother forms of periodontal therapy
cannot be successful.cannot be successful.

 The use of ultrasonic instrumentation isThe use of ultrasonic instrumentation is
recommended for calculus removalrecommended for calculus removal
followed by root planning with sharpfollowed by root planning with sharp
periodontal curettes.periodontal curettes.

Eliminating of local irritatingEliminating of local irritating
factors other than calculus:factors other than calculus:
 OverhangingOverhanging
restoration marginsrestoration margins
& open contacts allow& open contacts allow
food impaction, andfood impaction, and
should be correctedshould be corrected
before beginningbefore beginning
definitive prostheticdefinitive prosthetic
treatmenttreatment..

Elimination of gross occlusalElimination of gross occlusal
interferencesinterferences
 Can lead to rapid loss of periodontalCan lead to rapid loss of periodontal
attachment due to bacterial plaqueattachment due to bacterial plaque
accumulation.accumulation.
 Can be corrected by various techniques, ofCan be corrected by various techniques, of
which, selective grinding is the generallywhich, selective grinding is the generally
applied procedure.applied procedure.

Use of a night guardUse of a night guard
 Removable acrylic resin splint with flatRemovable acrylic resin splint with flat
occlusal plane can be used effectively as aocclusal plane can be used effectively as a
form of temporary stabilization andform of temporary stabilization and
means to eliminate excessive lateralmeans to eliminate excessive lateral
forces due to clenching and grindingforces due to clenching and grinding
habitshabits

 Particularly useful before fabrication ofParticularly useful before fabrication of
denture, when one of the abutment teethdenture, when one of the abutment teeth
has been unopposed for an extendedhas been unopposed for an extended
period.period.

Minor tooth movementMinor tooth movement
 Malposed teeth can be corrected byMalposed teeth can be corrected by
orhtodontically repositioning.orhtodontically repositioning.

Second phaseSecond phase
(Definitive periodontal surgical phase)(Definitive periodontal surgical phase)
 Patient is reevaluated after initial therapy. InPatient is reevaluated after initial therapy. In
case, oral hygiene is at optimum level, but there iscase, oral hygiene is at optimum level, but there is
presence of pockets and osseous defects,presence of pockets and osseous defects,
periodontal surgery is considered.periodontal surgery is considered.
 Includes:Includes:
Free gingival graftsFree gingival grafts
Ossoues graftsOssoues grafts
Pocket reductionPocket reduction

Periodontal flap surgeryPeriodontal flap surgery

 Involves elevation of either mucosa aloneInvolves elevation of either mucosa alone
or mucoperiosteum.or mucoperiosteum.
 Most important goal is:Most important goal is:
to allow access to bone and rootto allow access to bone and root
surfaces for complete instrumentationsurfaces for complete instrumentation
Access for pocket elimination, cariesAccess for pocket elimination, caries
control, crown lengthening, rootcontrol, crown lengthening, root
amputation or hemisection, as requiredamputation or hemisection, as required
and access to furcation of the tooth.and access to furcation of the tooth.

 Osseous resection involves both osteoplastyOsseous resection involves both osteoplasty
and ostectomy.and ostectomy.
 Osteoplasty is reshaping of the boneOsteoplasty is reshaping of the bone
without removing tooth-supporting bonewithout removing tooth-supporting bone
 Ostectomy on the other hand involvesOstectomy on the other hand involves
removing of tooth-supporting bone.removing of tooth-supporting bone.

 Procedures that attempt at regenerationProcedures that attempt at regeneration
of the lost periodontal structures throughof the lost periodontal structures through
different tissue responses.different tissue responses.
 Rationale is based on the physiologicalRationale is based on the physiological
healing response of the tissue afterhealing response of the tissue after
periodontal surgery.periodontal surgery.
Guided tissue regenerationGuided tissue regeneration

Periodontal plastic surgery /Periodontal plastic surgery /
Mucogingival surgeryMucogingival surgery
 Procedures used to resolve problemsProcedures used to resolve problems
involving inter-relationship between theinvolving inter-relationship between the
gingiva & alveolar mucosa.gingiva & alveolar mucosa.

 Objective:Objective:
 Elimination of pockets that traverse theElimination of pockets that traverse the
mucogingival junctionmucogingival junction
 Creation of an adequate zone of attachedCreation of an adequate zone of attached
gingivagingiva
 Correction of gingival recessionCorrection of gingival recession
 Relief of pull of frena & muscle attachmentsRelief of pull of frena & muscle attachments
on gingival marginson gingival margins
 Correction of osseous defectsCorrection of osseous defects

 Commonly used procedures:Commonly used procedures:
 Lateral sliding flapsLateral sliding flaps
 Free gingival graftsFree gingival grafts
 Pedicle graftsPedicle grafts
 Subepithelial connective tissue graftsSubepithelial connective tissue grafts
 Edentulous ridge augmentationEdentulous ridge augmentation

Third phaseThird phase
(Recall Maintenance phase)(Recall Maintenance phase)
 Includes reinforcement of plaque controlIncludes reinforcement of plaque control
measures and thorough debridement of allmeasures and thorough debridement of all
root surfaces of supragingival & subgingivalroot surfaces of supragingival & subgingival
calculus & plaque.calculus & plaque.
 The frequency of recall appointments shouldThe frequency of recall appointments should
be customized for the patient depending onbe customized for the patient depending on
the susceptibility & severity of periodontalthe susceptibility & severity of periodontal
disease.disease.

 Patients with moderate to severePatients with moderate to severe
periodontitis should be recalled 3-4periodontitis should be recalled 3-4
monthly.monthly.

 Advantages of periodontal therapy:Advantages of periodontal therapy:
 Elimination of periodontal disease removes aElimination of periodontal disease removes a
primary etiological factor in tooth lossprimary etiological factor in tooth loss
 Provides a better environment for restorativeProvides a better environment for restorative
correctioncorrection
 Response of strategic, but questionable teethResponse of strategic, but questionable teeth
provides an important opportunity toprovides an important opportunity to
reevaluate their prognosis before finalreevaluate their prognosis before final
decision is made to include/exclude them indecision is made to include/exclude them in
the denture designthe denture design
 Overall patient response indicates the degreeOverall patient response indicates the degree
of cooperation to be expected in the future.of cooperation to be expected in the future.

Provision for periodontally weakenedProvision for periodontally weakened
teeth - Temporary splintingteeth - Temporary splinting
 Cause for tooth mobility should beCause for tooth mobility should be
determined, and eliminated.determined, and eliminated.
 Temporary immobilization can be doneTemporary immobilization can be done
and the response observed, that may beand the response observed, that may be
an indicator in establishing a prognosis ofan indicator in establishing a prognosis of
these teeth.these teeth.

 A tooth that has lost 50% of its bony supportA tooth that has lost 50% of its bony support
& is being considered as a terminal& is being considered as a terminal
abutment tooth for a class I & II partialabutment tooth for a class I & II partial
denture would be a poor candidate fordenture would be a poor candidate for
splinting to the adjacent tooth.splinting to the adjacent tooth.
 In a situation such as this the usual result isIn a situation such as this the usual result is
that the stronger of the teeth is weakened bythat the stronger of the teeth is weakened by
splinting procedure rather than the weakersplinting procedure rather than the weaker
tooth being strengthened.tooth being strengthened.

 Secondary mobility due to inflammatorySecondary mobility due to inflammatory
disease may be reversible, if the diseasedisease may be reversible, if the disease
has not destroyed too much of thehas not destroyed too much of the
attachment apparatus.attachment apparatus.
 Primary mobility due to occlusalPrimary mobility due to occlusal
interferences may be resolved afterinterferences may be resolved after
selective grinding.selective grinding.

 In some cases, teeth must be stabilized dueIn some cases, teeth must be stabilized due
to the loss of supporting structures.to the loss of supporting structures.
 This can be achieved byThis can be achieved by
Acid etching teeth with composite resinAcid etching teeth with composite resin
Fiber reinforced resinsFiber reinforced resins
Cast removable splintsCast removable splints
Intracoronal attachments (require cuttingIntracoronal attachments (require cutting
tooth surfaces & embedding rigidtooth surfaces & embedding rigid
connection between adjacent teeth).connection between adjacent teeth).

 After periodontal treatment, permanentAfter periodontal treatment, permanent
splinting can be achieved with 2 or moresplinting can be achieved with 2 or more
cast restorations, soldered or castcast restorations, soldered or cast
together, that may be cemented withtogether, that may be cemented with
either a permanent or temporary cement.either a permanent or temporary cement.
Permanent splintingPermanent splinting

 Major drawback of fixed splinting isMajor drawback of fixed splinting is
inability of patient to adequately clean theinability of patient to adequately clean the
splinted teeth.splinted teeth.

 It is important to recognize that fixedIt is important to recognize that fixed
splinting of posterior teeth providesplinting of posterior teeth provide
additional resistance to antero-posterioradditional resistance to antero-posterior
forces, but not medio-lateral forces.forces, but not medio-lateral forces.
 Thus, to obtain improved resistance,Thus, to obtain improved resistance,
splinting should extend to include 1 orsplinting should extend to include 1 or
more anterior teeth.more anterior teeth.

 Better method to obtain resistance toBetter method to obtain resistance to
lateral forces is by obtaining cross-archlateral forces is by obtaining cross-arch
stabilization by a removable prosthesis, instabilization by a removable prosthesis, in
the form of wide palatal strap (maxillarythe form of wide palatal strap (maxillary
arch) and lingual plate (mandibulararch) and lingual plate (mandibular
arch).arch).
 The major connector may be retainedThe major connector may be retained
with extracoronal (clasps) orwith extracoronal (clasps) or
intracoronal attachments.intracoronal attachments.

Overdenture abutmentsOverdenture abutments
 Teeth that have lost atleast 50%Teeth that have lost atleast 50%
supporting bone, but are strategicallysupporting bone, but are strategically
positioned in the arch, should be retainedpositioned in the arch, should be retained
for support to the prosthesis.for support to the prosthesis.
 Resist tissue-ward forces.Resist tissue-ward forces.

Correction of malalignmentCorrection of malalignment
 Teeth that are malposed facially orTeeth that are malposed facially or
lingually are frequently more difficult tolingually are frequently more difficult to
correct than overerupted or submergedcorrect than overerupted or submerged
teeth.teeth.
 Malaligned teeth compromise theMalaligned teeth compromise the
contours & positions of removable partialcontours & positions of removable partial
denture components.denture components.

 While minor malalignment corrections canWhile minor malalignment corrections can
be tried by altering design of partialbe tried by altering design of partial
denture, when possible.denture, when possible.

Orthodontic realignmentOrthodontic realignment
 Orthodontically moving theOrthodontically moving the
malpositioned tooth should be consideredmalpositioned tooth should be considered
first, whenever possible.first, whenever possible.

 In some cases, where a large number ofIn some cases, where a large number of
teeth are missing, the number,teeth are missing, the number,
distribution & periodontal considerationdistribution & periodontal consideration
of remaining teeth may not provideof remaining teeth may not provide
sufficient anchorage for orthodonticsufficient anchorage for orthodontic
correction.correction.
 Some patients may be unwilling orSome patients may be unwilling or
unable to undergo orthodontic therapy.unable to undergo orthodontic therapy.

 Other forms of treatment that must beOther forms of treatment that must be
considered include:considered include:
 Minor malalignment: recontouring axialMinor malalignment: recontouring axial
surfaces of malposed teethsurfaces of malposed teeth
 Moderate malalignment: placement ofModerate malalignment: placement of
crowns, where, tooth preparation shouldcrowns, where, tooth preparation should
permit correction of malalignment.permit correction of malalignment.
 In cases, where tooth preparation is suchIn cases, where tooth preparation is such
that it encroaches pulp, endodontic therapythat it encroaches pulp, endodontic therapy
should be opted prior to reduction, whereshould be opted prior to reduction, where
post & core is used to restore the crown.post & core is used to restore the crown.

 In cases of severe malalignment, extractionIn cases of severe malalignment, extraction
should be considered.should be considered.

Occlusal considerations:Occlusal considerations:
 Here one must evaluate the patientsHere one must evaluate the patients
occlusion, that is:occlusion, that is:
i.i. Type of occlusion patient hasType of occlusion patient has
ii.ii. Whether there is a need to change or modifyWhether there is a need to change or modify
the patients existing occlusionthe patients existing occlusion
iii.iii. Whether the intercuspal position is inWhether the intercuspal position is in
harmony with the patients centric jawharmony with the patients centric jaw
relationrelation
iv.iv. The status of the plane of occlusion and ofThe status of the plane of occlusion and of
the occlusal curvethe occlusal curve

To evaluate the existing occlusal plane orTo evaluate the existing occlusal plane or
occlusal curve on the diagnostic cast anocclusal curve on the diagnostic cast an
occlusal template is used.occlusal template is used.

Correction of occlusal planeCorrection of occlusal plane
 The occlusal plane in most partiallyThe occlusal plane in most partially
edentulous mouths will be uneven.edentulous mouths will be uneven.
 The severity of the irregularity willThe severity of the irregularity will
determine the treatment necessary todetermine the treatment necessary to
correct the condition.correct the condition.

 Teeth unopposed for a prolonged time tendTeeth unopposed for a prolonged time tend
to supraerupt.to supraerupt.
 Most often encountered in the posteriorMost often encountered in the posterior
dental arch segments.dental arch segments.
 Such teeth should be treated in relation toSuch teeth should be treated in relation to
the magnitude of the problems they createthe magnitude of the problems they create
& the importance of the teeth to the success& the importance of the teeth to the success
of the RPD.of the RPD.

The problems encountered by posteriorThe problems encountered by posterior
supraerupted teeth are usuallysupraerupted teeth are usually
1.Insufficient space in positioning the1.Insufficient space in positioning the
opposing prosthetic teethopposing prosthetic teeth
2.Their potential for causing occlusal2.Their potential for causing occlusal
traumatrauma ..

 Extruded teeth in the anterior dentalExtruded teeth in the anterior dental
arch segment pose an additionalarch segment pose an additional
problem of esthetics.problem of esthetics.
 Depending on theDepending on the degree ofdegree of
extrusionextrusion the probable treatmentthe probable treatment
varies.varies.

 When there is slight extrusion the toothWhen there is slight extrusion the tooth
poses no appreciable problems inposes no appreciable problems in
positioning the prosthetic replacement inpositioning the prosthetic replacement in
the opposing dental arch & has no potentialthe opposing dental arch & has no potential
for creating occlusal trauma.for creating occlusal trauma.

HenceHence no treatmentno treatment is needed.is needed.

 When tooth extrusion is moderate, theWhen tooth extrusion is moderate, the
extruded posterior tooth poses definiteextruded posterior tooth poses definite
problems, of moderate magnitude, thatproblems, of moderate magnitude, that
can be successfully managed bycan be successfully managed by
various techniques.various techniques.

Enameloplasty/ SelectiveEnameloplasty/ Selective
grinding of the tooth cuspsgrinding of the tooth cusps

 It consists of reducing cusp height in orderIt consists of reducing cusp height in order
to level or harmonize the curve of theto level or harmonize the curve of the
occlusal plane.occlusal plane.
 Amount of correction accomplished by thisAmount of correction accomplished by this
technique is limited.technique is limited.
 When cusp height is reduced, the anatomyWhen cusp height is reduced, the anatomy
of the occlusal surface should be preserved.of the occlusal surface should be preserved.

 Functional cusp with accessory groovesFunctional cusp with accessory grooves
and sluiceways must be restored to theand sluiceways must be restored to the
teeth once the necessary reduction hasteeth once the necessary reduction has
been madebeen made ..

 It is best accomplished by using taperedIt is best accomplished by using tapered
diamond cylinder stones in the high speeddiamond cylinder stones in the high speed
handpiece.handpiece.
 Air-water spray should always be used toAir-water spray should always be used to
prevent creating excess heat during theprevent creating excess heat during the
procedure.procedure.
 Cut enamel surface should be polished toCut enamel surface should be polished to
remove scratches, using carborandumremove scratches, using carborandum
containing rubber wheel or points.containing rubber wheel or points.

 Treatment of the tooth surface withTreatment of the tooth surface with
fluoride gel effectively raises the fluoridefluoride gel effectively raises the fluoride
content of the enamel & increases thecontent of the enamel & increases the
surface resistance to dental caries.surface resistance to dental caries.

 When tooth extrusion is moderately severe,When tooth extrusion is moderately severe,
the tooth cannot be successfully managedthe tooth cannot be successfully managed
without altering the tooth to such a degreewithout altering the tooth to such a degree
that the enamel is penetrated, thusthat the enamel is penetrated, thus
requiring the placement of a restorationrequiring the placement of a restoration
(usually a cast restoration).(usually a cast restoration).

CAST CROWNSCAST CROWNS
 When crown height of the tooth must beWhen crown height of the tooth must be
changed to harmonize with the occlusalchanged to harmonize with the occlusal
plane, the facial, lingual or proximalplane, the facial, lingual or proximal
surfaces must be altered to produce a moresurfaces must be altered to produce a more
desirable height of contour, guiding planedesirable height of contour, guiding plane
or retentive undercut, a full crown isor retentive undercut, a full crown is
normally the restoration of choice.normally the restoration of choice.

 When restoring the tooth with a surveyedWhen restoring the tooth with a surveyed
crown one can create retentive undercutscrown one can create retentive undercuts
& guiding planes surfaces in the wax& guiding planes surfaces in the wax
pattern precisely where they will be mostpattern precisely where they will be most
advantageous to the overall design. Theadvantageous to the overall design. The
surface of the tooth that is to support thesurface of the tooth that is to support the
reciprocal arm of the clasp likewise bereciprocal arm of the clasp likewise be
ideally contoured.ideally contoured.

 Before reduction, the casts should beBefore reduction, the casts should be
mounted to ascertain the amount ofmounted to ascertain the amount of
reduction required.reduction required.
 In case, reduction is so great as toIn case, reduction is so great as to
endanger the pulp, endodontic treatmentendanger the pulp, endodontic treatment
should be doneshould be done

 When tooth extrusion is severe & the tooth isWhen tooth extrusion is severe & the tooth is
considered nonessential to the success of theconsidered nonessential to the success of the
prosthesis, it may be extracted.prosthesis, it may be extracted.

Infraerupted teethInfraerupted teeth
 Infraerupted teeth create defects in the planeInfraerupted teeth create defects in the plane
of occlusion & they can be successfullyof occlusion & they can be successfully
managed by:managed by:
 orthodontic treatmentorthodontic treatment
 placement of cast restoration on the tooth toplacement of cast restoration on the tooth to
increase the clinical crownincrease the clinical crown
 Use of an occlusal onlay as a part of the RPDUse of an occlusal onlay as a part of the RPD
or as an onlay rest to restore the clinical crownor as an onlay rest to restore the clinical crown
to the plane of occlusionto the plane of occlusion

1.orthodontic treatment1.orthodontic treatment

2.placement of cast restoration2.placement of cast restoration
on the tooth to increase theon the tooth to increase the
clinical crownclinical crown

3.3.Use of an occlusal onlay as aUse of an occlusal onlay as a
part of the RPD or as an onlay restpart of the RPD or as an onlay rest
to restore the clinical crown to theto restore the clinical crown to the
plane of occlusionplane of occlusion

 The occlusal surface of a tooth to be coveredThe occlusal surface of a tooth to be covered
by an onlay rest should be free of pits &by an onlay rest should be free of pits &
fissures or should be made so by eliminatingfissures or should be made so by eliminating
the defects with small burs or stone. Thethe defects with small burs or stone. The
smooth occlusal surface helps prevent cariessmooth occlusal surface helps prevent caries
caused by dental plaque & other debriscaused by dental plaque & other debris
trapped & held against vulnerable toothtrapped & held against vulnerable tooth
surfaces. Use of this rest in mouths withsurfaces. Use of this rest in mouths with
poor oral hygiene can lead to destruction ofpoor oral hygiene can lead to destruction of
teeth.teeth.

 If the onlay rest is to be constructed ofIf the onlay rest is to be constructed of
chrome alloy, any opposing natural teethchrome alloy, any opposing natural teeth
should not occlude directly against the rest.should not occlude directly against the rest.
Chrome alloy, being extremely hard, willChrome alloy, being extremely hard, will
cause rapid wear of the opposing enamelcause rapid wear of the opposing enamel
surfaces.surfaces.

 If the onlay rest must be used under theseIf the onlay rest must be used under these
circumstances, the chrome metal should becircumstances, the chrome metal should be
constructed short of occlusal contact & theconstructed short of occlusal contact & the
surface of the metal covered withsurface of the metal covered with
projections of metal beads. Tooth coloredprojections of metal beads. Tooth colored
acrylic resin may be processed on theacrylic resin may be processed on the
surface of the onlay rest with the beads usedsurface of the onlay rest with the beads used
to retain the resin. However the acrylicto retain the resin. However the acrylic
resin will wear fairly rapidly & will requireresin will wear fairly rapidly & will require
replacement more frequently than anreplacement more frequently than an
acrylic denture tooth.acrylic denture tooth.

 Tipped molars also present problems inTipped molars also present problems in
establishing a harmonious occlusal plane.establishing a harmonious occlusal plane.

 The design requirements for the RPD canThe design requirements for the RPD can
usually be met by selective grindingusually be met by selective grinding
procedures when the degree of tilt isprocedures when the degree of tilt is
moderate (5moderate (500
-10-1000
). Molars with severe tilts). Molars with severe tilts
(15(1500
or more) require a more carefulor more) require a more careful
appraisal.appraisal.

 Such molars are best repositionedSuch molars are best repositioned
orthodontically. This better allows the forcesorthodontically. This better allows the forces
from the RPD to be distributed along the longfrom the RPD to be distributed along the long
axis of the tooth & eliminates the possibilityaxis of the tooth & eliminates the possibility
of interferences from clasp assemblies &of interferences from clasp assemblies &
major & minor connectors.major & minor connectors.

 Severely tipped mandibular molars with aSeverely tipped mandibular molars with a
lingual tilt may considerably interfere withlingual tilt may considerably interfere with
a lingual bar major connector duringa lingual bar major connector during
placement & removal of the prosthesisplacement & removal of the prosthesis
when the lingual bar is to be extended towhen the lingual bar is to be extended to
the distal surface of the tooth to support athe distal surface of the tooth to support a
clasp assembly. In such instances, when theclasp assembly. In such instances, when the
RPD framework is fully seated there will beRPD framework is fully seated there will be
a significant space between the lingual bara significant space between the lingual bar
& the alveolar mucosa.& the alveolar mucosa.

 A major connector so placed will interfereA major connector so placed will interfere
with tongue function, create the potential forwith tongue function, create the potential for
food entrapment & in general be annoyingfood entrapment & in general be annoying
to the patient. Tooth modifications generallyto the patient. Tooth modifications generally
cannot be done without penetrating thecannot be done without penetrating the
enamel, which will require one to place aenamel, which will require one to place a
cast restoration on the tooth.cast restoration on the tooth.

Preparation of abutment teethPreparation of abutment teeth
Abutment teeth may be grouped as follows:Abutment teeth may be grouped as follows:
1.Those requiring only minor modifications1.Those requiring only minor modifications
to their coronal portions.to their coronal portions.
2.Those requiring to have restorations2.Those requiring to have restorations
other than complete coverage crowns &other than complete coverage crowns &
3.Those requiring to have crowns (complete3.Those requiring to have crowns (complete
coverage).coverage).

 Abutment teeth that require only minorAbutment teeth that require only minor
modifications include teeth withmodifications include teeth with SoundSound
enamelenamel

 Those with smallThose with small
restorations notrestorations not
involved in theinvolved in the
RPD designRPD design

 Those withThose with
acceptableacceptable
restoration thatrestoration that
will be involved inwill be involved in
the RPD designthe RPD design

 Those that have existing crown restorationThose that have existing crown restoration
requiring minor modification that will notrequiring minor modification that will not
jeopardize the integrity of the crown, thatjeopardize the integrity of the crown, that
is, an individual crown or as the abutmentis, an individual crown or as the abutment
of a fixed partial denture.of a fixed partial denture.

 Complete coverage restorations provide theComplete coverage restorations provide the
best possible support for occlusal rests.best possible support for occlusal rests.
 An amalgam alloy restoration if properlyAn amalgam alloy restoration if properly
condensed is capable of supporting ancondensed is capable of supporting an
occlusal rest without appreciable flow overocclusal rest without appreciable flow over
a long period.a long period.
 In case of any doubt about the existingIn case of any doubt about the existing
amalgam restoration is there, it should beamalgam restoration is there, it should be
replaced with a new restoration.replaced with a new restoration.

 Continued improvement in dimensionalContinued improvement in dimensional
stability, strength & wear resistance ofstability, strength & wear resistance of
composite resin restorations will addcomposite resin restorations will add
another dimension to the preparation &another dimension to the preparation &
modification of abutment teeth formodification of abutment teeth for
removable partial dentures that should beremovable partial dentures that should be
less invasive than placement of completeless invasive than placement of complete
coverage restorations & more economical.coverage restorations & more economical.

Sequence of abutment preparation onSequence of abutment preparation on
sound enamel or existing restorationssound enamel or existing restorations
1.1. Proximal surfaces path of placementProximal surfaces path of placement
should be prepared to provide guidingshould be prepared to provide guiding
planes.planes.
2.2. Tooth contours should be modified,Tooth contours should be modified,
lowering height of contour, so thatlowering height of contour, so that
i.i. Origin of circumferential clasp arms mayOrigin of circumferential clasp arms may
be placed well below the occlusal surface,be placed well below the occlusal surface,
preferably at the junction of the middlepreferably at the junction of the middle
and gingival thirdand gingival third

ii.ii. Retentive clasp terminals may be placedRetentive clasp terminals may be placed
in the gingival third of the crown forin the gingival third of the crown for
better esthetics and better mechanicalbetter esthetics and better mechanical
advantageadvantage
iii.iii. Reciprocal clasp arms may be placed onReciprocal clasp arms may be placed on
and above a height of contour that is noand above a height of contour that is no
longer higher than the cervical portion oflonger higher than the cervical portion of
the abutment tooth.the abutment tooth.

3.3. After alterations of axial contours andAfter alterations of axial contours and
before rest seat preparations arebefore rest seat preparations are
instituted, an impression of the archinstituted, an impression of the arch
should be made in irreversibleshould be made in irreversible
hydrocolloid and cast formed, that ishydrocolloid and cast formed, that is
surveyed to determine the adequacy ofsurveyed to determine the adequacy of
axial alterations before proceeding withaxial alterations before proceeding with
rest seat preparations. If axial surfacesrest seat preparations. If axial surfaces
require additional recontouring, it canrequire additional recontouring, it can
be done at the same appointment.be done at the same appointment.

4.4. Occlusal rest areas should be preparedOcclusal rest areas should be prepared
that will direct the occlusal forces alongthat will direct the occlusal forces along
the long axis of the abutment tooth.the long axis of the abutment tooth.
Mouth preparation should followMouth preparation should follow
removable partial denture designremovable partial denture design
outlined on the diagnostic cast.outlined on the diagnostic cast.
Proposed changes to the abutment teethProposed changes to the abutment teeth
should be made on the diagnostic castshould be made on the diagnostic cast
and outlined to indicate the area,and outlined to indicate the area,
amount & angulation of modification toamount & angulation of modification to
be done.be done.

Abutment preparations usingAbutment preparations using
conservative restorationsconservative restorations
 Conventional inlay prepartations areConventional inlay prepartations are
permissible on proximal surface of a toothpermissible on proximal surface of a tooth
not to be contacted by minor connector.not to be contacted by minor connector.
 The proximal & occlusal surfaces thatThe proximal & occlusal surfaces that
support minor connectors requiresupport minor connectors require
different treatment.different treatment.

 Extent of coverage is governed by factors,Extent of coverage is governed by factors,
such as, extent of caries, presence ofsuch as, extent of caries, presence of
unsupported enamel walls & extent ofunsupported enamel walls & extent of
occlusal abrasion & attrition.occlusal abrasion & attrition.
 When an inlay is restoration of choice,When an inlay is restoration of choice,
certain modifications of outline form arecertain modifications of outline form are
necessary.necessary.

 To prevent buccal & lingual proximal marginsTo prevent buccal & lingual proximal margins
lying at or near minor connector or occlusallying at or near minor connector or occlusal
rest, these margins must be extended wellrest, these margins must be extended well
beyond the line angles of the tooth, that mightbeyond the line angles of the tooth, that might
be accomplished by widening the conventionalbe accomplished by widening the conventional
box preparation.box preparation.
 However, the margin of cast restorationHowever, the margin of cast restoration
produced may be quite thin & may be damagedproduced may be quite thin & may be damaged
by the clasp when placing or removing theby the clasp when placing or removing the
 Prevented by extending outline of box beyondPrevented by extending outline of box beyond
line angle.line angle.

 Pulp in these preparations is endangeredPulp in these preparations is endangered
unless, axial wall is curved to conform tounless, axial wall is curved to conform to
the external proximal curvature of thethe external proximal curvature of the
tooth.tooth.
 Gingival seat should be so placed, toGingival seat should be so placed, to
ensure access to maintain good oralensure access to maintain good oral
hygiene.hygiene.
 Every effort should be made to provideEvery effort should be made to provide
restoration with maximum resistance &restoration with maximum resistance &
retention & clinically imperceptibleretention & clinically imperceptible
margins.margins.

 This can be achieved by preparingThis can be achieved by preparing
opposing cavity walls 5opposing cavity walls 500
or less fromor less from
parallel & producing flat floors & sharp,parallel & producing flat floors & sharp,
clean line angles.clean line angles.

Abutment preparation usingAbutment preparation using
crownscrowns
 When multiple crowns are to be restoredWhen multiple crowns are to be restored
as abutments, it is best that all waxas abutments, it is best that all wax
patterns be made at the same time.patterns be made at the same time.
 This can be accomplished with eitherThis can be accomplished with either
removable dies or solid cast withremovable dies or solid cast with
individual dies to refine the margins.individual dies to refine the margins.

 After cast is placed on the surveyor toAfter cast is placed on the surveyor to
conform to the selected path of placementconform to the selected path of placement
& after wax patterns have been& after wax patterns have been
preliminary carved for occlusion,&preliminary carved for occlusion,&
contact, the proximal surfaces that are tocontact, the proximal surfaces that are to
act as guiding planes are carved parallelact as guiding planes are carved parallel
to the path of placement with a surveyorto the path of placement with a surveyor
blade.blade.
 Guiding planes are extended fromGuiding planes are extended from
marginal ridge to the junction of themarginal ridge to the junction of the
middle and gingival 3middle and gingival 3rdrd
of the involvedof the involved
tooth surface.tooth surface.

 Guiding plane should not be extended toGuiding plane should not be extended to
the gingival margin, as the minorthe gingival margin, as the minor
connector must be relieved when itconnector must be relieved when it
crosses the gingiva.crosses the gingiva.
 After the guiding planes are parallel &After the guiding planes are parallel &
any other contouring is accomplished toany other contouring is accomplished to
accommodate the removable partialaccommodate the removable partial
denture design, occlusal rest seats aredenture design, occlusal rest seats are
carved in the wax pattern.carved in the wax pattern.

Preparing guiding planesPreparing guiding planes

 Guiding planes are naturally occurringGuiding planes are naturally occurring
or prepared parallel areas on verticalor prepared parallel areas on vertical
tooth surfaces that are contacted bytooth surfaces that are contacted by
certain rigid parts of the RPDcertain rigid parts of the RPD
framework during the placement &framework during the placement &
removal of the prosthesisremoval of the prosthesis ..

 Guiding planes should be prepared on soundGuiding planes should be prepared on sound
enamel or on appropriately restored toothenamel or on appropriately restored tooth
surfaces.surfaces.
 The instrument used to prepare guidingThe instrument used to prepare guiding
planes is generally a smoothplanes is generally a smooth diamonddiamond
stonestone with either awith either a cylindric or taperedcylindric or tapered
pointpoint. Keeping the long axis of the diamond. Keeping the long axis of the diamond
instrument parallel with the path ofinstrument parallel with the path of
placement when the selective grindingplacement when the selective grinding
procedures are performed usually createsprocedures are performed usually creates
effective guiding surfaces.effective guiding surfaces.

LengthLength
 Guiding planes should be longerGuiding planes should be longer
(occlusogingivally) for(occlusogingivally) for tooth supportedtooth supported
than forthan for distal extensiondistal extension prosthesesprostheses ..

 Proximal guiding planes for allProximal guiding planes for all tooth-tooth-
supportedsupported prostheses should beprostheses should be
approximatelyapproximately one half –two thirdsone half –two thirds thethe
length of the occlusogingival dimension oflength of the occlusogingival dimension of
the coronal enamel. The guiding planethe coronal enamel. The guiding plane
should extend from the marginal ridgeshould extend from the marginal ridge
cervically.cervically.

 Guiding planes on teeth that serve, asGuiding planes on teeth that serve, as
abutments forabutments for distal extensiondistal extension prosthesesprostheses
should beshould be one- third to one halfone- third to one half thethe
occlusocervical dimension of the coronalocclusocervical dimension of the coronal
dimension of the coronal enamel.dimension of the coronal enamel.

WidthWidth
 From an occlusal view, guiding planes onFrom an occlusal view, guiding planes on
proximal tooth surfaces may be slightlyproximal tooth surfaces may be slightly
curved buccolingually to more or less followcurved buccolingually to more or less follow
the natural tooth contour. Buccolingually,the natural tooth contour. Buccolingually,
guiding planes on proximal tooth surfacesguiding planes on proximal tooth surfaces
should be aboutshould be about two-thirdstwo-thirds as wide as theas wide as the
distance between the buccal & lingual cuspdistance between the buccal & lingual cusp
tips.tips.

Modifying survey linesModifying survey lines
Survey lines can be modified bySurvey lines can be modified by
1.Changing the tilt of the diagnostic cast1.Changing the tilt of the diagnostic cast
2.Selectively grinding the tooth2.Selectively grinding the tooth
3.Placing an appropriate cast restoration3.Placing an appropriate cast restoration
4.Placing an enamel bonded resin veneer.4.Placing an enamel bonded resin veneer.

Tilting the diagnostic castTilting the diagnostic cast

Mouth preparation for removable partial denture/ dental education in india

Mouth preparation for removable partial denture/ dental education in india

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