Dental Post-Curing and Resin Composite

Study Notes

Indirect Resin Composite Restorations

Post-curing can be done with a post-cure unit, under heat with or without curing light or curing box.
Advantages over ceramics include:
- Reduced or no lab fee if done in clinic
- Ready repairability of material intraorally
- Possibility of occlusal surface adjustment
- Easy removal if replacement becomes necessary
- More user-friendly in clinic and lab
Disadvantages compared to direct resin composite include:
- More tooth structure is required to be removed to obtain flared cavity walls
- Reliable chemical bonding doesn't occur between the restoration and the resin cement
Disadvantages compared to ceramics include:
- Adhesion of resin cement is more reliable to ceramic restorations
- Ceramic restorations provide long-term occlusal stability, which resin composite may not provide
Cavity design is the same as that described for ceramic restorations
Fabrication of indirect resin composite restoration:
- Indirect technique employs an impression of the prepared tooth and fabricates the inlay on a die
- Can be performed as either a one-visit or two-visit method
- Care must be given not to subject thin sections to direct occlusal forces
- Tooth resistance includes:
  - Parallel or perpendicular cavity walls to force direction
  - Walls following the enamel rods directions
  - Rounded but definite line angles
  - Cavity outlines following the sweeping curves
- Restoration resistance is not a crucial issue due to the inherent strength property of this material
- Axial retention is mainly encountered by friction of opposing walls, governed by the degree of wall tapering, length, roughness, and cement type

Ceramic Restorations

Advantages over metallic restorations include:
- Color blending with adjacent tooth structure
- Durable color match
- Low plaque accumulation
- Lower thermal diffusivity
- Increased fracture resistance of the restored tooth
Disadvantages include:
- Technique sensitive
- Time-consuming fabrication and placement
- Probability of unbonded restoration fracture during try-in phase
- Number of appointments and laboratory fee
- Potential of wearing of opposing tooth
- Occlusal adjustment results in loss of surface colorants
Indications include:
- Extensive tooth involvement with undermined or weak enamel
- Metal allergy
Cavity preparation design:
- Internal cavity walls must be uniformly tapered occlusally
- Cavo-surface margin should be beveled
- Gingival seat Cavo-surface margin should be trimmed with GMT
- All internal line angles must be well defined but not sharp
- Secondary flares are necessary for creating obtuse angled marginal tooth structure
Resistance and retention form:
- Cast gold restorations have high strength properties, giving the restoration bulk is not a prime request