Indications
1. For badly decayed, fractured, traumatized teeth, and as individual restorations.
2. As a retainer for bridge and RPD.
3. To correct mal alignment and mal occlusion.
4. Endodontic treated teeth will become brittle because
5. non-vital tooth.
6. access opening.
7. So the tooth will be week and need full coverage
8. Best retention and resistance.
Contraindications
1. Bulky sound tooth .
2. Eshetic critical area
3. Short edentulous span.
Advantages
1. Conservative if compared to PFM
2. Retentive resistance more than partial coverage
3. More structural durability
4. More marginal integrity
5. Easier to do
Disadvantages
1. Less conservative than RPD
2. Plaque accumulation
3. Galvanic current
4. metal display
5. Coverage for extra tooth structure
Steps
· occlusal reduction
· functional cusp reduction
· lingual surface reduction
· proxiaml surface reduction
· finishing of the preparation
Occlusal reduction (posterior) or incisal reduction (anterior)
· Are done for structure durability
· Depth orientation grooves: 1mm or 1.5 mm groves we connect them together following the anatomy of the tooth
· in lower teeth:
· 1.5mm occlusal reduction in buccal cusps (functional cusps)
· 1mm for lingual cusps
· In upper teeth:
· 1mm occlusal reduction in buccal cusps
· 1.5mm for lingual cusps
· Functional cusps should be beveled after the occlusal reduction
Axial reduction
· Done to increase retention and resistance and marginal integrity.
· In buccal and lingual reduction we use the turbido bur. the bur must be tilted occlusally, if not under cut will occur. Or we use the round end tapered diamond bur and hold it parallel with the long axis of the tooth
· To open the contact we use long thin tapered diamond for anterior teeth
· And short thin tapered diamond bur for posterior teeth
· We finish the preparation 0.5-1mm from supraginigval.
Click here to Download Compare and Contrast among Full Crowns, PFM anterior, PFM posterior, Three quarter anterior and Three Quarter Posterior
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