fixed partial dentures

lecture given 8/27/2026

why should we replace a missing tooth/teeth?

correction of existing disease, prevention of future disease, restoration of function, improvement of appearance

fixed partial denture

any dental prostheses that are luted, screwed, or mechanically attached or otherwise securely retained to natural teeth, tooth roots, and/or dental implants/abutments that furnish the primary support for the dental prothesis and restorating teeth in a partial edentulous arch

it cannot be removed by the pt

what are the components of an FPD?

retainer crown, connector, pontic, abutment

retainer crown / fixed dental prothesis retainer

the part of a fixed partial denture that unites the abutment(s) to the remainder of the restoration

connector

the portion of a fixed partial denture that unites the retainer(s) and pontic(s)

pontic

an artificial tooth on a FPD that replaces a missing natural tooth, restores its function, and usually restores the space previously occupied by the clinical crown

abutment

a tooth, or a portion of a tooth that serves to support and/or retain a prosthesis

what treatment considerations should you make when replacing a missing tooth/teeth

FPD should be designed as simply as possible

abutment teeth should be selected and examined carefully

span length/evaluation of the edentulous space

pt condition

ante’s law

the root surface of the abutments should be higher or equal to the root surface of the teeth being replaced

is ante’s law based in evidence?

not really

crown to root ratio

a measure of the length of tooth occlusal to the alveolar crest of bone compared with the length of root embedded in the bone

what is the optimal crown to root ratio for a tooth being considered as an abutment for an FPD?

2:3, with 1:1 being the maximum acceptable ratio

root morphology when evaluating abutment teeth

roots that are broader labiolingually than mesiodistally are preferable to roots that are round in cross-section

mutli-rooted teeth with widely separated roots will offer better periodontal support than roots that converge, fuse, or generally present a conical configuration

unless bone support has been weakened by advanced periodontal disease, a single missing tooth can almost always be replaced by a ________ that includes _______

3 unit FPD, one mesial and one distal abutment tooth

excessive flexing can lead to…

fracture of a porcelain veneer, breakage of a connector, loosening of a retainer, or unfavorable soft tissue response

the relationship between deflection and length of span (is/is not) linear

is not

the deflection will be ___ x greater if the span length is doubled

8

the deflection will be ___x greater if the span length is tripled

27

how can you minimize flexure?

create connectors that are as large as possible for optimal strength

double width of connector = double stability

double height of the connector with single width = 8x stability

connectors should not impinge on gingival tissues and be at least 1mm above the crest of the interproximal soft tissue

connectors should be designed to…

counter the forces being applied to the restoration under function

in posterior restorations, occlusal forces are mainly…

vertical

in anterior restorations, in addition to vertical forces, _____ stress in a ____ direction is caused by _____ and _____ movements

horizontal

sagittal

protrusive

lateral

t/f connector dimensions are critical for fracture resistance of monolithic lithium disilicate FPDs

true

with FPDs, a gingival embrasure with a broader radius of curvature reduced stress concentration under loading and…

improved fracture resistance at the gingival area of the connector

what are the types of fixed partial dentures?

conventional tooth supported FPD

resin-bonded tooth supported FPD

implant supported FPD

all can be all metallic, metal and ceramic, or all ceramic

is there a difference between metal or ceramic FPDs?

survival rates are equal (100%)

success rates differ- 80% for zirconia and 100% for metal ceramic

conventional tooth supported FPD

most common method for replacing a missing tooth

will use an abutment tooth on each end of the edentulous space

tooth preparation and margin design should follow standard guidelines according to the planned restorative materal (all metal, metal/ceramic, all ceramic)

why is proper reduction important?

lack of clearance/reduction is the number 1 reason for a remake

proper reduction allows for the restoration to have correct contours, esthetics, and strength

where do you not want occlusal reduction to be? (slide42)

at the junction of 2 materials- should be entirely on one materal

pontic design

must be carefully designed and fabricated to facilitate plaque control and adjust to existing occlusal conditions

cleansable tissue surface, access to abutment teeth, no pressure on ridge

shaped to look like a tooth, correct alignment to edentulous ridge, sufficient space for material

rigidity, strong connectors, well designed framework

height and width should allow placement of a pontic that appears to emerge from the ridge and mimics the appearance of the neighboring teeth

loss of residual ridge contour may lead to…

esthetic problems, food impaction, and percolation of saliva during speech

pontics with tissue contact

ridge lap (saddle)

modified ridge lap

ovate

conical

pontics without tissue contact

sanitary (hygienic), modified sanitary (hygienic)

seiberts class I

faciolingual loss of tissue width with normal ridge height

seiberts class II

loss of ridge height with normal ridge width

seiberts class III

combination of loss in both dimensions

what biologic considerations are needed for pontic design?

related to maintenace and preservation of the residual ridge

ridge contact should be pressure free to prevent ulceration and inflammation and occur exclusively on keratinized attached tissue

as the surrounding tissues change with the loss of a tooth, a pontic cannot exactly duplicate the loss tooth

t/f FPDs are always easy to clean, pts don’t need to be educated on efficient OHI

false- caries are #1 complication of FPD

what pontic design should you never use?

saddle/ridge lap, it cannot be cleaned!

what is the recommended location, advantages, disadvantages, indications, contraindications, and possible materials for a sanitary/hygienic pontic?

recommended locations: posterior mandible

advantages: good access for oral hygiene

disadvantages: poor esthetics

indications: nonesthetic zones, impaired oral hygiene

contraindications: where esthetic is important, minimial vertical dimension

materials: all metal

what is the recommended location, advantages, disadvantages, indications, contraindications, and possible materials for a conical pontic?

recommended locations: molars without esthetic requirements

advantages: good access for oral hygiene

disadvantages: poor esthetics

indications: posterior areas where esthetics are of minimal concern

contraindications: poor oral hygiene

materials: metal-ceramic, all resin, all ceramic

what is the recommended location, advantages, disadvantages, indications, contraindications, and possible materials for a modified ridge lap pontic?

recommended locations: high esthetic requirement like anterior teeth and premolars, some max molars

advantages: good esthetics

disadvantages: moderately easy to clean

indications: most areas with esthetic concern

contraindications: where where minimal esthetic concern exists

materials: metal-ceramic, all resin, all ceramic

what is the recommended location, advantages, disadvantages, indications, contraindications, and possible materials for an ovate pontic?

recommended locations: very high esthetic requirement like max incisors, canines, and premolars

advantages: superior esthetics, negligible food entrapment, ease of cleaning

disadvantages: necessitates surgical preparation, not for residual ridge defects

indications: desire for optimal esthetics, high smile line

contraindications: pt unwillingness to undergo surgery, residual ridge defects

materials: metal-ceramic, all resin, all ceramic

what is the recommended location, advantages, disadvantages, indications, contraindications, and possible materials for a modified ovate pontic?

recommended locations: very high esthetic requirement like max incisors, canines, and premolars

advantages: superior esthetics, negligible food entrapment, ease of cleaning

disadvantages: necessitates surgical preparation

indications: where horizontal ridge width is not sufficient for a conventional ovate pontic

contraindications: pt unwillingness to undergo surgery

materials: metal-ceramic, all resin, all ceramic

resin bonded tooth supported FPD

may have one abutment tooth on each side of the edentulous space OR abutment(s) on one end only

what is the issue with 2 abutment resin bonded tooth supported FPD?

one can get de-cemented which can lead to caries

has a higher failure rate than cantilever FPDs

what are the advantages of resin bonded tooth supported FPD?

reduced cost, no anesthetic needed, supragingival margins, minimal tooth preparation

what are the disadvantages of resin-bonded tooth supported FPD?

irreversible, longevity, no major alignment correction possible, cannot be used in pts with deep occlusal vertical overlap

what is most important to minimize fatigue caused by cycling?

the number and distribution of occlusal contacts on an all ceramic FPD

what are some preparation modifications you can make when planning/designing an FPD?

retentive boxes and grooves

double abutments

arch curvature- when pontics lie outside of the inter-abutment axis line, the pontics act as lever arms

pier abutment

tilted molar abutments

cantilever FPD

double abutments

using 2 teeth on each side of the edentulous space instead of just one

possible consideration to overcome unfavorable crown to root ratio

the secondary abutment must have at least as much root surface area, favorable crown to root rato, and be as retentive as the primary abutments

when looking at arch curvature, secondary retention must extend…

a distance from the primary inter-abutment axis equal to the distance that the pontic lever extends in the opposite direction

pier abutment / intermediate abutment

a natural tooth or implant abutment that is located between terminal abutments that serve to support a fixed or removable dental prosthesis

because of the curvature of the arch, the faciolingual physiologic moveemnt of the anterior teeth occurs at a considerable angle to the faciolingual movement of a molar

to attempt to overcome the bending motion, a non-rigid connector can be used

when you have a pier abutment, where should the location of the stress-breaking device be?

distal to the pier! if placed here, movement in a mesial direction will seat the key into the keyway

if placed mesial, mesially directed movement will unseat the key

what should you do in the case of tilted molar abutment?

ortho

if pt declines ortho…

FPD can be created using a proximal half crown as a retainer on a tilted molar abutment, telescope crown and coping as a retainer on a tilted molar abutment, or a non-rigid connector on the distal aspect of a premolar retainer can compensate for the inclination of the tilted molar

cantilever FPD

abutment(s) are located on one end only

generally should be used to replace one tooth and have at least 2 abutments

not ever recommended to do on a distal extension

t/f FPD don’t need to be temporized as the intended final restoration

false! they must be to avoid supraeruption or drifting

t/f abutments must be prepped parallel to each other for a path of insertion

true duh