Sandwich technique for Class V restorations

By Dr.Swathi Pai on Friday, 25 April, 2008 with 0 comments

  • A technique used to prevent class V resin failure at the gingival margin due to open margins from polymerization shrinkage, which breaks the bond to dentin

  • Glass ionomer is used because of its
  1. fluoride release mechanism
  2. thermal expansion/contraction is close to tooth structure
  3. chemical adhesion to enamel and dentin
  4. biologically compatible

  • place groove at 1/2 gingival wall with 1/4 or 33 1/2 bur
  • remove smear layer with polyacrylic acid or ADA approved substitute (delete this step for Vitrabond)
  • place GI liner over exposed dentin
  • bevel occlusal enamel (1 mm)acid etch enamel margin and glass ionomer liner for 20 seconds; a minimal amount of GI cement is lost during the etching process; a 15-30 second etch results in loss of 4 microns for “G-C liner” and 12-18microns for Ketac Bond; rinse for 20 seconds. (Not necessary to etch Vitrabond liner)
  • apply bond agent(s)
  • cure composite resin in two (2) increments; place the gingival increment first and cure for 60 seconds; add the incisal increment and cure for an additional 60 seconds

Category: Conservative and Endodontics Notes



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