Dental Post-Curing and Resin Composite

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