FIXED FIXED PARTIAL PARTIAL DENTUREDENTURE

CLASSIFICATIOCLASSIFICATIONN and TYPES of and TYPES of

FPDFPD

1. SIMPLE FIXED 1. SIMPLE FIXED BRIDGEBRIDGE

A. Rigidly Fixed Bridge-permits no individual or independent movements of its parts and is also known as STATIONARY FIXED BRIDGE

B. Semi –Fixed Bridge-one which allows some individual or separate movements of some of its parts and is also known as LIMITED STATIONARY / BROKEN STRESS BRIDGE

C. Cantilever Bridge

-one which has one or more abutments at one end of the bridge while the other end is unsupported

2. COMPOUND FIXED 2. COMPOUND FIXED BRIDGEBRIDGE

-a combination fixed partial denture which employs two or more of the simple type in one restoration

Rigidly fixed bridge

SUBCLASSIFICATION ACCORDING TO LOCATIONA. Anterior or Labial Bridge

- Limited to incisor regionB. Posterior or Buccal Bridge

- from canine posteriorly to include premolars and molars

C. Combination Antero-Posterior Bridge or Labio-Buccal bridge- includes anterior and posterior teeth

COMPONENTCOMPONENTS OF FIXED S OF FIXED

BRIDGEBRIDGE

1. Abutment It is the selected remaining tooth or teeth where a crown or a bridge is attached

2. RetainerIt is the It is the artificial artificial crown or crown or crowns used crowns used to attach the to attach the bridge to the bridge to the abutment abutment tooth/teeth.tooth/teeth.

3. Pontic artificial crown

used to restore the missing tooth or teeth in the arch and may either be:all porcelain; porcelain fused to metal; plastic attached to metal; and all plastic

4. Connector Serves to

connect retainer on one side to the other retainer on the other side of the bridge as well as unites all the other parts of the bridge

FACTORS THAT FACTORS THAT INFLUENCE THE INFLUENCE THE COMPONENTS COMPONENTS SELECTION SELECTION

A. AbutmentA. Abutment with vital pulpwith vital pulp with normal amount of with normal amount of

periodontal attachmentperiodontal attachment capable of supporting capable of supporting

additional forces to additional forces to which it will be subjected which it will be subjected as part of the FPDas part of the FPD

its preparation must be its preparation must be such that its retentive such that its retentive power shall be power shall be sufficient to resist the sufficient to resist the displacing forces to displacing forces to which it will be exposedwhich it will be exposed

B. RetainerB. Retainer- - must be so designed that it must be so designed that it has sufficient strength has sufficient strength

- margins prevent irritation of - margins prevent irritation of the soft tissues and the soft tissues and recurrence of cariesrecurrence of caries

- must be self-cleansing- must be self-cleansing

- does not corrode or - does not corrode or tarnishtarnish

- does not discolor- does not discolor

- it is aesthetic- it is aesthetic

C. Pontics C. Pontics -restore the function of the tooth it replaces-restore the function of the tooth it replaces

-meet the demands of esthetics and comfort-meet the demands of esthetics and comfort

-be biologically acceptable to the tissues-be biologically acceptable to the tissues

- ensure its sanitation- ensure its sanitation

-prevent tissue inflammation of underlying -prevent tissue inflammation of underlying residual ridge mucosaresidual ridge mucosa

4. Connector4. Connector connector should be

approximately 2mm. in size Connector should always pass

through what would be normal contact area of teeth being replaced

allows for creation of normal embrasures and interdental spaces

Incisal/occlusal surface of connector should never have sharp edge, which presents cleavage point to porcelain

Connector should be contoured interproximally to allow for equal porcelain coverage on adjoining teeth

Proper placement of connector in the anterior and posterior teeth

Characteristics: All surfaces should be

convex, smooth and properly finished

The occlusal table must be in functional harmony with the occlusion of all the teeth

The overall length of the buccal surface should be equal to that of the adjacent abutments/pontic

Anterior and Posterior Anterior and Posterior Pontic DesignPontic Design

The lingual contour should be in harmony with adjacent teeth or pontics

Factors Influencing

Fixed Bridge Design

1. Crown Length-teeth must have adequate occlusocervical crown length to achieve sufficient retention

2. Crown Form

- some teeth have tapered crown form which interferes with parallelism

- incisors possessing very thin highly translucent incisal edges

3. Degree of Mutilation- size, number and

location of carious lesions or restorations affect whether full or partial coverage retainers are indicated

- fractured or carious teeth not restorable should be removed thereby altering design and creating the need for a prosthesis

4. Root Length and Form- roots with parallel sides and developmental

depressions are better able to resist additional occlusal forces than are smooth-sided conical roots

- multirooted teeth generally provide greater stability than single-rooted teeth

- longer root has better retention than short root

5. Crown-Root Ratio- 1:1.5 ratio has been generally

acceptable whereas 1:1 ratio is considered minimal and requires consideration of other factors (ex. # of tth being replaced, tooth mobility, periodontal health) before it can be used as an abutment

6. Ante’s Law-periodontal ligament area/pericemental area of

the abutment teeth should be equal or greater than the periodontal ligament area/pericemental area of the missing tooth/teeth

1

7. Periodontal Health- absence of any form of periodontal disease such as bone resorption and gingival recession

8. Mobility – MILLER MOBILITY VALUE1o mobility – normal2o mobility – still acceptable

provided that you must know the factor that cause the mobility (px age, presence of calcular deposit) and consider the # of tth being replaced

3o mobility – can not be used as an abutment/for extraction

9. Span Length-distance between abutments affects the feasibility of placing fixed prosthesis- ideal for 1-2 missing tth- loss of 3 adjacent tth requires careful evaluation of other factors (crown-root ratio, root length and form, periodontal health, mobility)

Primary abutment

Secondaryabutment

10. Axial Alignment- crowns of proposed abutments must be well aligned- minor alterations in axial alignment (tipped/rotated) often necessitate the use of full coverage crowns to achieve retention or acceptable esthetics

11. Arch Form

fulcrum line fulcrum line

lever lever

counter-balancing

12. Occlusion- occlusal forces brought

to bear on a prostheses are related to the ff:a. degree of muscular activityb. patients habitc. # of tth being replacedd. leverage on the bridgee. adequacy of bone support

13. Pulpal Health- abutment/s should not

be sensitive to percussion or vitality testing

- abutments with poor pulpal health should undergo endodontic tx prior to tooth preparation

14. Alveolar Ridge Form- not indicated for FPD if

there is considerable bone loss

Vertical bone lossHorizontal bone loss

15. Age of Patient- not indicated in

older patient as well as adolescents when teeth are not fully erupted or with large pulps

16. Phonetics- patients prefer FPD

for good phonation (provides sufficient resistance to the flow of air to allow normal speech sounds to be produced) rather than RPD

17. Long-Term Abutment Prognosis

- take note of the oral hygiene-if there is question on the

ability of the remaining supporting structure to accept additional occlusal forces, RPD is indicated

- tooth with sufficient loss of periodontal support and questionable prognosis may be best treated with an RPD rather than an FPD

18. Esthetics-prefer FPD because it

resembles natural tooth-but RPD may be

indicated when the use of a pontic produces large and unsightly proximal embrasures in a fixed prostheses.

19. Psychological Factors- to most pxs an FPD feels

more normal than an RPD and more quickly becomes an accepted part of the oral environment

- px feels more confident and looks good wearing FPD than RPD