CROWN RETENTION WITH USE OF A 5-PERCENT GLUTARALDEHYDE SEALER ON PREPARED DENTIN

Statement of problem. A previous study showed that a resin sealer decr eased casting retention with zinc phosphate cement. Purpose. This stud y determined whether a nonresin sealer applied to prepared dentin affe cted the retention of cemented castings. Material and methods. Extract ed molars were prepared with a flat occlusal, 20-degree taper and 4 mm axial length. The axial surface area of each preparation was determin ed and samples were distributed to achieve equivalent groups. Gluma De sensitizer sealer was used to seal the dentin before provisionalizatio n and again before crown cementation. An Olympia alloy casting was pro duced for each preparation and cemented with a seating force of 20 Kg with either Mizzy's zinc phosphate, Ketac-Cem glass ionomer, or Resino mer material in combination with One Step adhesive. Castings were ther mocycled, then removed along the path of insertion with an Instron tes ting machine. A two-factor analysis of variance was used with alpha = 0.05 and n = 9-10. Results. Mean dislodgment stresses for unsealed and sealed conditions were 6.3 and 6.4 MPa for zinc phosphate, 9.1 and 10 .1 MPa for glass ionomer, and 12.1 and 12.6 MPa for the resin cement. The means for the three cements were statistically different (P < 0.00 1). The effect of sealer (p = 0.369 ) and cross product interactions ( P = 0.820) were not significant. Conclusions. The use of the glutarald ehyde-based system as a desensitizing treatment for prepared teeth had no effect on crown retention for any of the three cements evaluated a nd the modified resin cement produced the highest mean dislodgment str ess that exceeded the strength of the tooth.