Treatment Planning for Fixed Prosthodontics Flashcards
Treatment plan should be presented in….form and should be
Written from, discussed in detail with the patient.
Developing the treatment plan steps
- Collecting diagnostic data.
- Sequence of mouth preparation:
evaluation of oral hygiene and occ. Analysis. Oral surgery.
periodontal treatment.
Endodontically treatment.
Orthodontic treatment. Operative
Fixed and removable treatment. - Rational for proposed plan of treatment i.e. choosing a particular plan of treatment.
- Prognosis and its justification.
Treatment planning for single tooth restoration:
INTRACORONAL RESTORATION:
When sufficient coronal tooth structure
EXTRA-CORONAL PROSTHESIS:
If insufficient coronal tooth structure
Removable partial denture:
Indications:
1) Edentulous space greater then two posterior teeth, anterior space greater than four incisors.
2) Space that include canine and two other contiguous teeth.
3) An edentulous space with no distal abutment.
4) Multiple edentulous spaces.
5) Bilateral edentulous spaces with more than two teeth missing on one side.
Multiple edentulous span: Distribution
each can be restored with a fixed partial denture yet due to expenses and technical complexities a removable partial denture is used
When a missing tooth is to be replaced, a…. is preferred
by the majority of patients.
FBD
Resin bonded tooth supported fixed partial denture: Indications:
1) Caries free abutment teeth.
2) Maxillary and Mandibular incisors replacements.
3) Single posterior tooth replacement.
4) Young patient with favorable occlusion.
Implant supported fixed partial denture: Indications:
- Insufficient number of abutment teeth.
- Inadequate strength in the abutments to support a
conventional FPD. - Patient unable to wear RPDs.
- Where there is no distal abutment.
Implant supported fixed partial denture: Indications:
- Insufficient number of abutment teeth.
- Inadequate strength in the abutments to support a
conventional FPD. - Patient unable to wear RPDs.
- Where there is no distal abutment.
No prosthetic treatment:
If
a patient presents with a long standing edentulous space
poor prognosis =
extraction might be the best choice in such case.
Questionable prognosis ex
advanced bone loss, grade III furcation involvements, inaccessible area, presence of systemic factors.
Consequence of removal without replacement:
a. Supraocclusion of the opposing tooth or teeth.
b. Tilting of the adjacent teeth.
c. Loss of proximal contact.
d. Disturbance in the health of the supporting structure and the occlusion.
Correction of overerupted opposing tooth
- 2.
- 5.
6.
Orthodontic repositioning.
Simple contouring of plunger cusp and topical application of fluoride.
Occlusal veneers or Onlay. Crowning of over-erupted tooth.
Endodontic treatment and crowning of over- erupted tooth.
Extraction.
- 5.
Factors affecting the selection of prosthesis type:
- Biomechanicalconsiderations.
- Theprospectiveabutment.
- Estheticrequirements.
- The patient desires.
- Financial factors.
- Clinicalskills.
- Laboratorysupport.
- Patient’smotivationandexpected cooperation.
In addition to the increased load placed on the periodontal ligament by a long span fixed partial denture, longer spans are….
less rigid.
If a single tooth pontic span is deflected a certain amount a two pontic span will bend 8 times as much and three teeth will bend 27 times…. Etc.
If a pontic with given occ.gingival dimension will bend certain a mount, if it’s thickness is decreased by half it will bend 8 times as much.
Clinical sequels of bridge bending:
- Fracture of porcelain veneers.
- Connectors breakage.
- Retainer loosening.
- Unfavorable soft tissue response.
How to overcome bridge bending
the solution will be :
Pontics with greater occ.gingival dimension.
Alloy of high modulus of elasticity.
Increase retention form in preparation.
Connecters should be as bulky as much possible.
Use of double abutments ?
Alternative treatment modalities for long span edentulous area:
Implant supported F.P.D R.P.D
Biomechanical considerations:
On Arch form:
has its effect on the stresses occurring in a FPD constructed in the anterior segment, especially in the upper anterior region.
It was suggested to involve the two 1st premolar together with the canines in the replacement of missing four maxillary incisors to gain excellent retention.
Ideal abutment =
Caries free
After caries removal and undermined enamel the remaining sound
tooth structure should be assessed to:
- Select the most suitable type of restorative materials and retentive means.
- Doubtful pulpal condition or capped pulp shouldn’t be used as fixed prostheses abutment
Endodontically treated tooth is contraindicated to be used as retainer for
cantilever bridge
Endodontically treatment is done
intentionally for suspected or malaligned tooth to improve the arch relationship.
sufficient retention:
a. over-erupted teeth: they should be adjusted to normal occlusal plane even restored or endodontically treated.
Best known through
mounted diagnostic cast analysis
Short crown design and preparation?
Design:
• Fixed-fixed bridge must be done.
• Full coverage retainer with retentive means.
• Pontic and connectors should be of considerable occluso-gingival to enhance resistance to bending.
Preparation:
• Sub-gingival finish line.
• Decreaseconvergence
• Decrease occlusal reduction (metal).
• Crownlengtheningprocedures.
Crown form
Tapered crown form:
• decreased retention so must use full coverage.
e.g. anterior teeth with poorly development cingulum,
mandibular with short lingual cusps.
Incisors with very thin labio-lingual dimension– increase incisal translucency in the incisal edge, nor partial coverage neither resin bonded bridge.
Root portion and periodontal ligament condition , aspects should be evaluated
- Crown/Root ratio (C/R ratio) .
- Periodontal ligament surface area (Ant’s law).
- Root shape and alignment.
- Mobility.
The optimum crown / root ratio for a tooth to be utilized as a fixed partial denture abutment is
2:3
The C/R ratio is liable to change throughout life (aging or periodontal disease)
A C/R of 1:1 is the minimum acceptable ratio to be used but under the following conditions:
a) Favorable opposing occlusion ( artificial prosthesis or mobile periodontally involved teeth).
b) NormalOcclusalpattern.
c) Abutment teeth with good periodontal condition.
d) Highly motivated patient.
e) Favorable root configuration.
Periodontal ligament surface area (Ant’s law):
the sum of periodontal ligaments area of the abutments teeth should be equal to or exceed the total periodontal ligament area of tooth or teeth to be replaced.
Factors modifying Ant’s law:
- Well motivated patients and highly proficient in plaque control.
- Opposing occlusion (sound natural dentition or artificial removable prosthesis).
- Decreased in mesiodistal length of edentulous span due to bodily movement of teeth.
Root shape and alignment
• Larger and longer roots are more favorable abutment teeth.
• Form of the root is equally important tapered or conical roots are unfavorable
Multi-rooted teeth with…..and…are better than single rooted or Multi-rooted with fused roots.
divergent and curved roots
Position of roots of adjacent tooth is also important, in case the roots are
close with little interproximal bone separating them even a moderate irritation of force may be destructive.
The magnitude and cause of mobility should be evaluated:
Grade I : suitable
Grade II : can be used in short span bridges. Grade III : contraindicated.
Special problems:
- Pier abutment
- Tilted molar abutments
movement can create stresses on the abutment teeth as well as between the retainers as a result of the middle abutment acting as
a fulcrum causing failure of the weaker retainer
The use of…… (stress breaking mechanical union of retainer and pontic ) has been recommended to reduce this hazard.
non rigid connector
The location of the stress breaking device is important usually located on the…. of the pier abutment.
distal side
Early loss of a mandibular first molar with mesial tilting and drifting of the second and third molars.
Treatment options ?
It is very difficult to make a fixed partial denture with a common path of insertion without interference with the adjacent tooth and over-reduction of the mesial half of the 7
Treatment modality:
Extract the third molar and upright the tilted 2ndmolar orthodontic ally.
If orthodontic correction is impossible:
Modified preparation design. Proximal half crown : 3⁄4 crown.
Non-rigid connector on the distal aspect of the premolar retainer
Telescopic crown:
used as a retainer on the distal abutment
A full crown preparation with heavy reduction is made to
follow the long axis of the tilted molar
inner coping is made to fit the tooth preparation
the proximal half crown that will serve as the retainer for the fixed partial denture is fitted over the coping.
In Canine-replacement fixed partial dentures , Maxillary more difficult than mandible due to
labially and lingually acting force respectively,
Cantilever fixed partial dentures is
FDPs in which only one side of the pontic is attached to a retainer,
