BOND STRENGTH OF REPAIRED ANTERIOR COMPOSITE RESINS - AN IN-VITRO STUDY

The objectives of this study were to investigate the repair potential of two commercially available composite resins in terms of bond streng th, and the effectiveness of two commercially available adhesive syste ms used as intermediary materials in the repaired specimens. The repai r strength of Helio Progress (HP) and Herculite XRV (XRV) was tested u sing two bonding agents: DenTASTIC (DT) and All Bond 2 (AB2). The effe ct of surface abrasion of specimens and the effect of time on repair s trength were also investigated. Surface abrasion significantly improve d the bond strength (P < 0.001) and the use of bonding agents further enhanced bond strength but not significantly. Use of bonding agents al one improved the repair bond strength significantly (P < 0.001). Repai r of HP with HP after surface abrasion and application of DT produced the highest repair bond strength which was 99% of the cohesive strengt h of the control (unrepaired) specimens. Although there were some diff erences in the bond strength over the time period of the study (one mo nth) none of these was statistically significant. It is concluded that surface abrasion coupled with the application of bonding agent produc es the highest repair strength. It seems likely that clinically accept able bond strengths are possible after repair of anterior composite re sins. (C) 1998 Elsevier Science Ltd. All rights reserved.