3. RBFPD Flashcards
1
Q
What are the five requirements to resin cements for RBFPD’s?
A
- Strong bond to metal or ceramic
- Strong bond to enamel
- High compressive, flexural, and tensile strength
- Low film thickness
- Auto or dual cure
2
Q
Current RBFPD design concepts
- Minimal/maximum enamel coverage
- ___ degree design
- Grooves or rests/cingulum stops?
- Path of draw must be in a __ direction as much as possible to minimize __ displacement (O/G or B/L)
A
- Maximum enamel
- 180
- Cingulum grooves and occlusal rests
- O/G direction, minimize B/L displacement
3
Q
Proximal/lingual reduction
- Depth of reduction?
- Do we want a buccal-lingual lock?
- Start __ mm from occlusal edge in posteriors
- Start __ mm from incisal edge in anteriors
A
- 0.25 - 0.5
- Yes, buccal-lingual lock
- Start 1 mm from occlusal edge
- Start 2 mm from incisal edge
4
Q
Placement of grooves
- Depth?
- Create one path of __
- Apical aspect __ mm away from chamfer margin
- What kind of bur to use?
A
- 0.5 to 1 mm
- Insertion
- 1 mm
- Tapered fissure bur (169L/170L)
5
Q
Advantages of RBFPD’s
- Tooth structure removal?
- Pulpal trauma risk?
- Anesthesia?
- Supra or sub gingival preparation?
- Easy or difficult to make impression?
A
- Minimal removal
- Minimal risk
- Usually no anesthesia
- Supra gingival
- Easy to make impression
6
Q
Advantages of RBFPD’s
- Provisional required?
- Increased/reduced chair time
- Increased/reduced patient expense
- Rebonding a possibility?
A
- Not usually required
- Reduced
- Reduced
- Rebond possible, but usually indicates failure
7
Q
Disadvantages of RBFPD’s
- Increased/reduced restoration longevity
- Enamel modifications required?
- Is space correction possible?
- Is alignment and occlusion a factor?
- Are esthetics ideal on posterior teeth?
A
- Reduced longevity
- Enamel modifications required
- Space correction difficult or impossible
- Must have ideal alignment and occlusion
- Esthetics compromised on posterior teeth
8
Q
RBFPD’s - Indications
- Length of span?
- Abutment condition
- Crown length needed?
- Lateral forces?
- Moisture control a factor?
A
- One or two teeth anteriorly and one posteriorly
- Unrestored or minimally restored abutments
- Adequate crown length
- Minimal lateral forces on pontic
- Need excellent moisture control
9
Q
RBFPD’s - Contraindications (14)
A
- Parafunctional habits
- Long edentulous spans
- Short crown height
- Mod to heavy restored abutments
- Thin translucent anterior teeth
- Unable to keep prep in enamel
- Compromised enamel
- Unable to maintain isolation
- Excessive pontic space
- Deep vertical overlap
- Allergy to base metal
- Mod to heavy lateral forces will exist on pontic
- Mod/high caries risk
- Mobile teeth as primary abutments
10
Q
Shakal paper conclusions
- Did metal surface area and design of tooth prep have an effect on strength and durability?
- What did occlusal coverage improve?
A
- Yes, substantial
2. Retention and resistance form
11
Q
Shakal paper conclusions
- What does placement of grooves or increasing bonding area improve?
- Combo of what two features improved strength durability of bonding joints?
A
- Improves strength and durability
2. 180 degree opposing grooves/channels and lingual wraparound
12
Q
Survival rates for single vs double retained FPD’s are higher
A
Single retained FPD’s
