• If excess of pressure is applied by the metal framework or the resin
on the tooth, it is carefully identified using disclosing wax and
relieved using high-speed carbide bur.
Gagging: It occurs commonly due to overextended maxillary denture.
Overextension is removed using stone bur.
Cheek biting: Cheek biting is caused by trapping of the cheek mucosa
between the posterior occlusal tables. This is caused by improper
placement of the artificial teeth with insufficient horizontal overlap.
It is corrected by proper placement of teeth or by selectively
grinding mandibular buccal cusp.
Tongue biting: This is caused by lower posterior teeth arranged too far
lingually into the tongue space. It is corrected by reshaping the
lingual surfaces of the teeth or by proper positioning of the
Pain on chewing: This could be due to occlusal discrepancy. Occlusal
discrepancy or prematurities are identified and corrected by
selective grinding. The patient is advised soft diet during the early
Problems with phonetics: This can be due to change in contour of the
speech area such as anterior part of the palate or because of
improper positioning of the anterior teeth. In such situations:
• The patient should be given some time to adjust to
• If the problem is due to contour, adjustment should
• If the problem is due to improper positioning of the
teeth, teeth should be removed and repositioned in
Relining is defined as ‘the procedure used to resurface the tissue side of the
removable dental prosthesis with new base material, thus producing an
accurate adaptation to the denture foundation area’. (GPT 8th Ed)
• When partial denture has lost its fit.
• The indication of the partial denture requiring relining procedure is
assessed by visual inspection of the loss of supporting tissues.
It can be inspected by two methods:
1. Using thin mix of alginate: A thin mix of alginate is placed on the
tissue surface of the denture. It is placed firm in position till it sets.
The bulk of alginate is assessed. If =2 mm of alginate is present, then
2. Finger pressure: Finger pressure is applied at the distal end of the
denture base and the amount of anterior lift of the indirect retainer is
evaluated. If the amount of space below the indirect retainer is more
than 2 mm, the relining procedure is indicated.
• Uniform amount of resin is removed from the tissue surface of the
• Autopolymerizing resin is mixed by following the manufacturer’s
• The external surface of the denture base is covered with an adhesive
• The mixed resin is applied over the tissue surface of the denture
• The denture is secured in proper position and the resin is allowed to
• Once the resin is completely polymerized in 12–15 min, the denture
• This method of reline is inferior to the laboratory reline method and
should be used in temporary situations.
Uniform amount of resin is removed from the tissue side of the
denture base and the undercut region because of the following
• There should be adequate space for the impression material so that
the material does not displace the soft tissues.
• The tissue side of the resin should be removed in order to make
• Selection of the impression material depends on the condition of the
• If the tissues are mobile, the free-flowing zinc oxide paste is used.
• If the tissues are firm and tightly bound to the ridge, silicones,
polysulphide or functional waxes can be used.
• Once the impression material is loaded, the denture is seated on the
ridge with firm pressure and the tooth–denture relationship is
• The patient should not bite till the set impression is removed from
• Denture is invested in one-half of the flask with a stone replica of
the tissue surface of the denture base in the other flask.
• Both the flask should close completely.
• Once the invested material sets, the flasks are opened and the
impression material from the denture base is removed.
• After applying separating media on the cast, the resin is mixed
following the manufacturer’s instructions and packed.
• Both the flasks are closed completely.
• Once polymerization of the resin is complete, deflasking is done in
conventional manner and the denture is finished and polished.
• Alternately, the relined impression can be mounted on a duplicating
Special removable partial dentures
Guide plane removable partial denture
Guide plane RPDs are used to stabilize periodontally weakened teeth
in three directions, i.e. mesiodistally, vertically and buccolingually.
Fixed partial denture, if periodontically compromised, provides
stabilization only in buccolingual direction. Therefore, RPD is
preferred in periodontally compromised dentition as it provides cross-arch
Guide plane RPD consists of multiple guide planes, multiple rests,
clasps and rigid major and minor connectors (Fig. 21-1).
• Design is based on broad stress distribution principle.
• Stress is distributed through rigid major and minor connectors and
• It is essential to note that all the clasps will not be retentive but are
useful in stabilizing the dentition and preventing tooth movement.
• Only two of the clasps on both sides should be retentive and the
remaining clasps should be designed such that these lie above the
• The reciprocal arm should contact the tooth before the retention arm
to reduce the lateral forces on the teeth.
• Framework should have a passive fit.
• Multiple parallel guide planes are essential in the design.
• To determine parallelism between the teeth, intraoral paralleling
• May not work in cases with severe bone loss
• Contraindicated in Kennedy’s class IV cases
• It is indicated in supporting periodontically weakened mandibular
• It provides cross-arch stabilization and support to the remaining
• It helps in stabilizing the teeth by splinting action.
• Mesial and distal incisal rests can be prepared on the anterior teeth
and engaged into the lingual plate by metallic extension.
• Also, lingual plate prevents food impaction between the
interproximal spaces between the teeth.
FIGURE 21-2 Lingual plate provides cross-arch stability and
Disjunctor is defined as ‘any component of the prosthesis that serves to
allow movement between two or more parts’. (GPT 8th Ed)
Disjunct dentures are special type of stress breakers which consist
These dentures are indicated in distal extension partial dentures
where the remaining teeth are periodontically compromised.
• In the lower, lingual plate is used as major connector which is
supported at both the ends by rests and clasps.
• It has a small projection which is called the disjunct bar.
• This bar engages into the disjunct slot which is housed in the
• The bar–slot connection allows freedom of movement during
• This helps in minimizing stress transferred to the abutment teeth
which are already periodontically compromised.
• It is used in periodontally compromised dentition.
• It allows freedom of movement and reduces stress on abutment.
• It results in patient discomfort due to movement of the parts.
• It is difficult to construct.
• Wearing of the parts occurs.
Spoon denture is defined as ‘a maxillary provisional removable dental
prosthesis, without clasps, whose palatal resin base resembles the shape of a
• It is indicated in Kennedy class IV partial dentures in the maxilla.
• It is used as provisional partial dentures during the course of
periodontal treatment as plaque control is easy.
• This denture does not have any clasp and is confined to the central
• It resembles a spoon (Fig. 21-4).
• It does not contact the lingual surfaces of any tooth.
• Any premature contact will highly compromise on the retention of
FIGURE 21-4 Spoon denture is indicated in class IV partial
• It can be used as interim dentures in periodontically compromised
• It makes plaque control easier.
• There are less chances of food impaction and caries.
Recently there has been renewed interest in digitally designed RPDs
with the use of high precision scanners, CAD/CAM software and 3D
printers. The CAD/CAM designed partial dentures have eliminated
multiple time-consuming traditional laboratory procedures in the
• The master cast of the patient is digitally surveyed and scanned.
• The computer software and rapid prototyping technology
integrated with 3D printing are used to design a sacrificial pattern.
• This pattern is then casted using chromium–cobalt alloy or titanium
• The metal framework is finished and polished and the fit is adjusted
• Less chances of error (porosity, defects in casting, etc.)
• Initial time required for training
In these dentures, the entire framework and the essential components
are fabricated using flexible nylon polyamide denture base resins. The
retention is provided by flexible nylon retentive clasps. The dentures
are fabricated using injection moulding technique in specially
designed flasks. The flasking and the dewaxing procedures are similar
to that followed in compression moulding technique, e.g. Valplast
One drawback of flexible RPDs is that these do not contain any
vertical displacement component such as occlusal or canine rests.
These RPDs depend solely on the soft tissues (residual ridge) for
• Shim stocks are useful in verifying the presence and location of the
• Spoon denture is the maxillary interim RPD which is without clasp
and whose palatal resin base resembles the shape of the spoon. It is
usually used during periodontal treatment.
22. Introduction to fixed prosthodontics
23. Diagnosis and treatment planning in fixed
24. Design of fixed partial denture
25. Clinical crown preparation in fixed
26. Impressions in fixed partial denture
29. Laboratory procedures in fixed prosthodontics
Indications of Fixed Partial Denture (FPD), 320
Replacement of missing teeth with fixed dental prosthesis helps in
improving function, aesthetics, comfort and speech of the patient.
Successful fixed restorative treatment begins with thorough diagnosis
and treatment planning which enhance not only comfort, aesthetics
and function but also harmony of stomatognathic system.
Fixed prosthodontics is defined as ‘the branch of prosthodontics
concerned with the replacement and/or restoration of teeth by artificial
substitutes that are not readily removed from the mouth’. (GPT 8th Ed)
Indications of fixed partial denture (FPD)
• In a patient who cannot tolerate removable prosthesis.
• In a patient with systemic condition such as epilepsy wherein fear of
aspiration of removable prosthesis.
• In case of short edentulous span.
• In a psychiatric and physically handicapped patient with limited
• Morphology of the abutment teeth requiring alteration.
• Greater stability during function enhances patient confidence and
• Teeth adjacent to the edentulous area requiring a restoration.
• Paediatric patients and young adults due to the presence of short
clinical crowns, large pulps, high caries rate and increased chances
• Inability of the patient to cooperate due to medical reasons
• Advanced periodontal disease
• Unfavourable condition of the abutment tooth/teeth
• Unfavourable tilting or rotation of the abutment teeth
• Bilateral edentulous span requiring cross-arch stabilization
• Large amount of tissue loss in the edentulous region
Fixed dental prosthesis or fixed partial denture (FPD) can be defined
as ‘any dental prosthesis that is luted, screwed or mechanically attached or
otherwise securely retained to natural teeth, tooth roots and/or dental
implant abutments that furnish the primary support for the dental
Fixed dental prosthesis is also commonly referred to as fixed bridge
FIGURE 22-1 Parts of fixed partial denture.
Abutment: A tooth, root or an implant which provides attachment to
Pontic: An artificial tooth or teeth that replace the missing tooth or
Retainers: A part of the FPD which connects the pontic and is
cemented onto the prepared tooth. It is of two types, namely,
extracoronal and intracoronal.
Connector: A part of the FPD that unites the retainer and the pontic. It
can be rigid or nonrigid depending on its indication.
FPDs can be classified into different types depending on the location,
span, abutment, connector and material.
FPDs can be broadly classified as follows:
On the basis of type of material used
On the basis of type of movement
(i) Fixed–fixed partial denture
(ii) Fixed–movable partial denture
(iii) Removable partial denture
On the basis of length of edentulous span
On the basis of type of abutment used
(vii) Pier abutment-supported FPD
On the basis of type of support provided at each end
(v) Combination or hybrid design
Retainer is defined as ‘any type of device used for the stabilization or
retention of prosthesis’. (GPT 8th Ed)
A retainer can be defined as a casting cemented to an abutment tooth
which retains or helps to retain a pontic.
Factors required for ideal retainer
• Retention qualities: Retainer should have adequate retention to bear
the functional forces. The axial walls of the preparation should be as
parallel as possible. Length of the edentulous span, type of design
and surface area are some of the factors which affect the retention of
• Strength: Adequate strength to resist deformation under functional
stresses is an important requirement for ideal retainer.
• Biological factors: Conservation of tooth structure, relation of
margins of restoration to the gingival tissues and contour of
• Aesthetic factors: These factors should be aesthetically pleasing.
(i) Class I: Extracoronal retainers
(ii) Class II: Intracoronal retainers
(iii) Class III: Radicular retainers
On the basis of type of material used
Selection of retainers depends on the following characteristics:
• Condition of the abutment tooth/teeth or implant: Height,
mesiodistal width, location, periodontal status and angulation are
some of the factors which greatly influence the selection of the type
of retainer (refer Chapter 23).
• Functional relation of adjacent gingival tissues: The axial contour
of the natural teeth, position of the contact areas and nature of the
embrasure greatly influence the health of the gingival tissues. Full
• Available interocclusal space: Amount of interocclusal space
determines the type of retainer that will be most suitable.
• Presence and extent of caries: This determines the type of retainer to
be selected. Small and shallow caries indicate intracoronal retainers,
whereas large and extensive caries demand the use of extracoronal
• Morphology of the crown of the abutment: To some extent, crown
morphology determines the type of retainers used. For example,
peg-shaped lateral usually requires complete coverage crown.
• Periodontal condition: The periodontal status of the abutment teeth
greatly influences the choice of retainer. More advanced generalized
chronic periodontal problem leads to gingival recession, bone loss
and even mobility. Splints or appropriate extracoronal retainers are
• Length of edentulous span: This will influence the extent of the
functional forces transmitted to the retainers. Longer the span,
greater will be the stresses and greater will be the need for bulk and
strength of retainers to resist torsional forces.
• Position of the tooth: Partial veneer crowns are usually indicated in
the anterior region and full veneer crowns are indicated in the
• Occupation, age and sex of the patient: Selection of appropriate
retainer is influenced by these factors as well. For example, younger
patients have higher pulp horn, and therefore, have higher chances
of pulpal damage than older patients.
Extracoronal retainers are cast metal restorations or crown that
encircles all or part of the remaining tooth structures. More tooth
structure is removed to provide adequate bulk for strength than
intracoronal restorations. These retainers are also sometimes referred
Types of extracoronal retainers
There are two types of extracoronal retainers, which are:
Intracoronal retainers are defined as ‘within the confines of the cusps
and normal/axial contours of a tooth’.
Intracoronal retainers lie within the normal contours of the clinical
Types of intracoronal retainers
Proximo-occlusal inlay (fig. 22-2).
Proximo-occlusal inlay is defined as ‘a fixed intracoronal restoration; a
dental restoration made outside a tooth to correspond to the form of the
prepared cavity, which is then luted onto the tooth’.
FIGURE 22-2 Proximo-occlusal inlay.
• Minimal caries or old restoration that requires a mesio-occlusal or
• Patient’s request for all ceramic or gold restoration instead of
• Parafunctional habits such as bruxism
• MOD increases the risk of fracture
• Poor dentinal support requiring extensive preparation
• Superior material properties
• No discolouration from corrosion
• Least complex cast restoration
• Less wear in comparison to composites
• Less conservative than amalgam
• Utilizes wedge retention which exerts some outward pressure on
• Accurate occlusion is difficult to achieve
• Intraoral adjustment is difficult as it is fragile before bonding
• Any adjustment requires careful finishing and polishing, which is
MOD onlay is a restoration that restores one or more cusps and adjoining
occlusal surfaces or the entire occlusal surface and is retained by mechanical
FIGURE 22-3 MOD onlay on maxillary first premolar.
• Worn/carious tooth with intact buccal and lingual cusps
• MOD amalgam requiring replacement
• MOD restoration with wide isthmus
• Patient with poor oral hygiene
• It provides support for cusps.
• It does not have adequate retention.
• It is less conservative than amalgam.
• Castable glass ceramic is less abrasion resistant than traditional
• Resin flash or overhangs are difficult to detect and clean, which
ultimately may lead to periodontal problems.
• Finishing of the margins is difficult in less accessible area.
Pontic is an artificial tooth or teeth that replace the missing natural
tooth or teeth to restore function, aesthetics, comfort and oral health.
Pontic is attached to the retainer with the help of a connector which
may be rigid or a nonrigid (Fig. 22-4).
FIGURE 22-4 Pontic is an artificial tooth replacing missing
Pontic is defined as ‘an artificial tooth on a fixed dental prosthesis that
replaces a missing natural tooth, restores its function and usually fills the
space previously occupied by the clinical crown’. (GPT 8th Ed)
Careful design selection is of utmost importance, as this will affect
the function, aesthetics, oral hygiene maintenance and patient comfort
• It should provide good aesthetics.
• It should be biologically acceptable.
• It should facilitate plaque control.
• It should provide comfort to the patient.
• It should have adequate strength.
• It should stabilize the occlusion.
• It should not impinge or apply pressure on the underlying tissue.
• It should aid in preserving health of the underlying tissues.
Selection of appropriate pontic design plays an important role in the
success of treatment with fixed prosthesis. The design of the pontic is
dictated by restoring the form, function and appearance of the tooth
The principles guiding design of the pontic are:
Factors affecting pontic design
• Tissue contact: The area of tissue contact between the pontic and the
ridge should be small and passive in nature. The area of pontic
contacting the tissue should be convex and, if possible, should only
contact the attached keratinized gingiva. The pontic should never
apply pressure or be placed on the movable tissue as it may cause
inflammation or ulceration of the underlying mucosa.
• Interproximal embrasure: There should be suf icient clearance in the
interproximal embrasure area to facilitate plaque control. Gingival
embrasure should be made wide so as to allow cleaning. In the
anterior region, the space provided is less due to aesthetic reasons
in comparison to the posterior region.
• Occlusal surface: The occlusal form of pontic should correspond to
the tooth it replaces. Usually, the width of the pontic should be 85%
of the original, although it is governed by factors such as strength of
the abutment, ridge form and contour and length of the edentulous
• Length of the span: Longer the span of FPD, more the stress will be
imposed on the pontic and the connector. As the length of the span
increases, there will be increased tendency of flexion of the FPD.
• Material used: Choice of the material to fabricate pontic is very
critical for the success of fixed restoration. The material should be
biocompatible, rigid and aesthetic. Usually, glazed porcelain contact
is provided with the tissue for easier oral hygiene maintenance.
• Ridge contour: Shape of the contour should be carefully studied to
provide an aesthetically successful pontic. In most anterior cases,
modified ridge lap is usually recommended. Although in the
posterior region, more hygienic pontic design is desirable.
Pontics can be classified on the basis of following characteristics:
(i) On the basis of mucosal contact
(ii) On the basis of type of material used ( Fig. 22-5)
(iii) On the basis of method of fabrication
FIGURE 22-5 Types of pontic based on the material: (A) all
metal; (B) metal and ceramic; (C) all ceramic; (D) metal and
(A) On the Basis of Mucosal Contact
(i) Ridge Lap or Saddle Pontic
• It is called ridge lap as it overlaps the ridge, both
labially and lingually (Fig. 22-6).
• It closely resembles the natural tooth because it
replaces all the contours of the missing tooth.
• It forms large concave contact with the ridge.
• This design obliterates the proximal, facial and
• The biggest disadvantage of this design is that it
is not possible to clean with dental aid like floss.
• Plaque accumulation leads to gingival
• This design is not recommended or indicated in
• In this design, the pontic contacts the ridge only
in the facial surface to give an illusion of a tooth
emerging from the gingiva (Fig. 22-7).
• The lingual surface does not contact the ridge and
has convex surface to aid in cleaning.
• The tissue contacting area should always be as
convex as possible because it facilitates plaque
• Ridge contact of this pontic design is ‘T’ shaped.
• The vertical arm of ‘T’ ends at the crest, whereas
the horizontal arm forms the contact along the
• This is the most aesthetic design and is
recommended commonly in the high aesthetic
areas such as upper and lower anterior teeth and
upper premolars and first molar.
• It is also called egg-shaped, bullet-shaped or
heart-shaped pontic (Fig. 22-8).
• It is rounded and provides good access for oral
• It is indicated in lower molar region with thin
• It has poor aesthetics and is, therefore, used in
areas of minimal aesthetic concern.
• This design is not suitable for broad flat ridges, as
small area of contact over broad ridge creates
• This design was called ‘sanitary dummy’ by E.T.
• This design has superior aesthetic with negligible
food entrapment and is easy to clean.
• This design gives an impression of the tooth
emerging from the gingiva (Fig. 22-9).
• Its convex surface is rounded and lies in the soft
• This area is easy to clean and floss.
• The concavity on the ridge can be created by
placing a temporary tooth into the extracted
• It can also be surgically created in pre-existing
• It is recommended in highly aesthetic areas, such
as maxillary incisor, canines and premolars.
• Its disadvantage is need for surgical preparation
(i) Hygienic or sanitary pontic
• This design allows easy cleaning, as there is no
contact with the residual ridge.
• It is usually recommended in unaesthetic zones
such as mandibular molar region.
• Pontic should be at least 3 mm thick
occlusogingivally (Fig. 22-10).
• There should be adequate space below the pontic
• This design of the pontic is made convex, both
faciolingually and mesiodistally.
• The undersurface of the pontic is made round to
facilitate easy flossing. This round undersurface
is referred to as fish belly (Fig. 22-11).
• Disadvantage of the fish belly design is that the
bulk of the connector is decreased and thereby
• It is also called arc-fixed partial denture, modified
sanitary pontic or Perel pontic (Fig. 22-12).
• This pontic design is hyperbolic paraboloid
shaped where the tissue surface of the pontic
forms a concave archway mesiodistally.
• The size of the connectors is increased here,
which increases its strength and also allows
• It is indicated in nonaesthetic zones such as
• It is contraindicated in aesthetic area and areas of
(B) On the Basis of Method of Fabrication
(I) Prefabricated pontic facings: These are
commercially available porcelain facings which are
preformed and are adjusted according to the
edentulous space. Some of the prefabricated designs
• This can be used in both anterior and posterior
• Occlusal surface is made of gold and the tissue
• This has a horizontal slot approaching from the
lingual aspect which accommodates both the
• To strengthen the gold supporting the pontic,
bevel is given on the lingual aspect to increase its
resistance to occlusal forces.
• Advantage: This has adequate strength, good
• Disadvantage: This should not be used where
• It is the reverse of trupontic.
• Here, gold contacts the ridge tissue and porcelain
provides the occlusal contact.
• It has a horizontal slot on the lingual aspect for
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