FPD Flashcards
ABSOLUTE contraindication for bruxism
(Full ceramic, FPD’s )
Porcelain
Zirconia
Largest tooth in the whole mouth
Maxillary first molar
Smallest tooth in the whole mouth
Mandibular central incisor
In an FPD, the limitation of a Pontiac
We can replace only up to 3 missing teeth
Moderately compromised edentulous area
Even if one canine missing in the arch
Totally healthy tooth with perfect pulpal system do we need to do an RCT when capping the tooth
No, it is not recommended in Canada
The height of the proximal plate
it will be starting actually UNDERNEATH the MARGINAL RIDGE of the abutment and then extend completely the proximal surface of the tooth .
Initial 1.5-2 mm has contact and then under the minor connector or base of RPD we have relief.
Decreased horizontal labial angle
When patient loses all the teeth, the lips will collapse, and the label angle decreases
Columella philtrum angle or nasolabial angle in a CD pt.
This angle will be INCREASED as the patient has lost all teeth and the lip collapses
Consequence of losing all teeth
Nasolabial angle will increase
Horizontal lip angle will decrease
Optimal crown root ratio
2:3
Ideal crown root ratio
1:1
Edentulous Ridge classification
1 ideally or minimally compromised edentulous area
. Single arch
.Anterior maxillary span, not exceeding 2 missing incisors
. Anterior mandibular span not exceeding 4 missing incisors
. Any posterior maxillary or mandibular spend not exceeding 2 premolars or 1 premolar, and 1 molar.
- Moderately compromised area.
. The above conditions in both arches.
. If Max or mandibular, canine is missing.
Canine is very important - Substantially compromised edentulous area.
Any posterior maxillary, or mandibular span greater than 3 missing teeth or two molars
Any edentulous span including anterior or posterior area of three or more missing teeth
The absolute maximum number of posterior teeth, which can be safely replaced with a fixed bridge
3
(only under ideal conditions)
When should we give a removable partial denture?
6
- an edentulous, space with NO distal abutment.
- A severe loss of tissue in the edentulous ridge
3 an insufficient number of abutments longer span or missing teeth is greater than three - Periodontally weakened primary abutment…. As cross art stabilization will help support little better distribution of RPD forces.
- An E dentulous fees involving four adjacent teeth, other than the four incisors
- If more than one Edentulous , space exists in the same arch.
Contraindications for fixed bridge work
7
- Poor oral hygiene.
- Hi cries rate
- Multiple spaces in the arch or teeth likely to be lost soon.
- Unacceptable occlusion.
- Severe BRUXISM, especially for full ceramic FPD’s
- If the clinical skill and technical skill of the dentist do not match the demands of the case
- Severe residue ridge resorption in anterior area, especially in patients with GUMMY smile.
RCT treated tooth
If the tooth is properly, treated, endodontically,it can well serve as an abutment with a post and core foundation for retention and strength
In an FPD a discrepancy between CO nd CR
It should be evaluated. Also, the forces of mastication and aesthetic considerations should be reviewed.
occlusion records for treatment planning for an FPD bridge should be matched at
CR or CO?
CR
Cantilevers
FPD’s’s in which only one side of the Pontic is attached to a retainer
Once it has abutment on the other side is free
Example lateral incisor
Important : cantilever is usually considered for 1 TOOTH
Prerequisites of a lateral incisor cantilever
Canines should be healthy
Periodontal support should be good
Occlusion should be favourable
No, bone loss at all
Disadvantages of a cantilever
Induces lateral forces on the supporting tissue, which may cause tipping rotation, or drifting of the abutments
One abutment is not enough
So we use multiple abutment teeth with sound periodontal support
Important points for a cantilever
Forces are best tolerated by the periodontal supporting structures, when directed along the LONG AXIS of the tooth
Cantilever FPD’s should replace only 1 tooth and have at least 2 abutments
When replacing a maxillary literal incisor, the canine used as an abutment should have a long root and a good bone support
There should be a REST on the MESIAL of the pontic against the restoration in an inlay or other metallic restorations to prevent rotation of the pontic and abutment
To give cantilever in a posterior too
We need to have 2 ABUTMENTS as we chew from posterior tooth. All the tooth may become mobile.
To give cantilever for missing first molar
We need to consider, if size of Pontiac, is same as the size of the replaced tooth, then too much force on the middle abutment the middle abutment will be acting like a fulcrum
Therefore, the considerations are:
Change the size of the pontic to a premolar and not a molar
In maximum Intercuspation, we should have light occlusion contact
No contact between teeth on excursion
connecter-important point
Should occupy the normal interproximally contact area.It should be large enough for STRENGTH but not so large as to IMPEDE PLAQUE CONTROL
Important point
An anterior fixed bridge is contra indicated when there is a considerable resorption of the residual ridge
example in trauma cases
If a tooth is properly treated endodontically
It can serve well as an abutment with a POST AND CORE foundation for retention and strength
The rest on pontic
Should be on the mesial of the Pontic against a rest preparation in an inlay or other metallic restoration
Should be on the distal of central incisor to prevent rotation of the Pontic and abutment
Cantilever anterior teeth
No contact
on CO as well as lateral excursions
For cantilever to replace the first premolar
Full veneer retainers are used on the second premolar and first molar abutments
Available materials for FPD
1.Cast metal:
Intracoronal restorations (inlays)
Extra coronal restorations (crowns )
- Metal ceramic material PFM.
- Fibre reinforced resin.
- Complete ceramic.
Intracoronal restorations ( inlays)
They rely on the strength of the remaining tooth structure for support and retention
Greater tooth bulk is needed to resist any vegging affect on the preparation walls
Contraindication -significantly weakened tooth
Extracoronal restorations Crowns
Encircle, all or part of the remaining tooth structure and the occlusal surface
The Crown strengthen and protects the teeth weekend by caries or trauma
Onlay
And only is an inly, which covers the cusps..but does not go all the way to the gingiva
They provide BETTER PROTECTION than inlay, but often LACK RETENTION
Metal ceramic, PFM
It’s amongst the least, conservative treatment especially Buccally
is used when a complete crown is needed to restore appearance and function
Fibre reinforced resin
Excellent marginal, adaptation, and aesthetics
Disadvantage : do not withstand functional load well overtime
Example INTEGRITY
Use: long-term interim restorations
Complete ceramics
Most aesthetic and least conservative
These days the current focus is to improve the strength of aesthetic restoration on either veneering, a high strength, alumina, zirconia, spinel, or lithium disilicate core..with the more translucent porcelain are using a leucite reinforced translucent materials..
Monolithic aesthetic, restorations
the strongest, ceramic restorations
colored monolith zirconium crowns, have very acceptable aesthetics for posterior teeth
