Effect of different surface treatments on the composite-composite repair bond strength.
The aim of this study was to investigate the effect of different mechanical and adhesive treatments on the bond strength between pre-existing composite and repair composite using two aging times of the composite to be repaired. Standardized cylinders were made of a microhybrid composite (Spectrum TPH) and stored in saline at 37 degrees C for 24 h (n = 140) or 6 months (n = 140). Three types of mechanical roughening were selected: diamond-coated bur followed by phosphoric acid etching, mini sandblaster with 50-microm aluminum oxide powder, and 30-microm silica-coated aluminum oxide powder (CoJet Sand), respectively. Adhesive treatment was performed with the components of a multi-step bonding system (OptiBond FL) or with a one-bottle primer-adhesive (Excite). In the CoJet Sand group, the effect of a silane coupling agent (Monobond-S) was also investigated. The repair composite (Spectrum TPH) was applied into a mould in three layers of 1 mm, each separately light-cured for 40 s. Repair tensile bond strengths were determined after 24-h storage. Mechanical and adhesive treatment had significant effects on repair bond strength (P < 0.001). The age of the pre-existing composite had no significant effect (P = 0.955). With one exception (CoJet Sand/OptiBond FL Adhesive), adhesive treatments significantly increased repair bond strengths to 6-month-old composite when compared to the controls without adhesive. Adhesive treatment of the mechanically roughened composite is essential for achieving acceptable repair bond strengths. The more complicated use of silica-coated particles for sandblasting followed by a silane coupling agent had no advantage over common bonding systems.
Department of Operative Dentistry and Periodontology, University of Ulm, D-89081 Ulm, Germany. andreas.rathke@uniklinik-ulm.de
Andreas
A
Rathke
Yana
Y
Tymina
Bernd
B
Haller
D000269:Adhesives; D020906:Air Abrasion, Dental; D003188:Composite Resins; D001840:Dental Bonding / Q000379:methods*; D045662:Dental Etching; D017269:Dental Prosthesis Repair; D003799:Dental Stress Analysis; D008689:Methacrylates; D019279:Resin Cements; D012821:Silanes; D013499:Surface Properties; D013997:Time Factors
D000269:Adhesives; D003188:Composite Resins; C420130:Excite cement; D008689:Methacrylates; C469607:OptiBond FL; D019279:Resin Cements; D012821:Silanes; C467914:TPH spectrum