Journal of Research in Dental and Maxillofacial Sciences

en Effect of Different Repair Protocols on Repair Bond Strength of Aged Composite Restorations Restorative Dentistry Restorative Dentistry Original article Original article <div style="text-align: justify;">Background and Aim: This study assessed the effects of composite type, adhesive type, adhesive application protocol, and storage time on repair microshear bond strength (µSBS) of composite restorations.    Materials and Methods: This in vitro, experimental study was conducted on Z350 and Point 4 (n=360) composite discs that were stored in water for 3 weeks at 37°C. After roughening by bur and etching, the specimens were divided into 24 groups (n=15) based on the type of composite (Z350 and Point 4), type of universal adhesive (G-Premio Bond and Clearfil Universal Bond Quick), adhesive application protocol (according to the manufacturer’s instructions, waiting for 30 seconds, or diode laser irradiation of adhesive prior to polymerization for 30 seconds), and storage time (24 hours or 1 year). The specimens were bonded to Z250 repair composite, and underwent µSBS test. The mode of failure was also determined. Data were analyzed by four-way ANOVA and Tukey’s test (alpha=0.05).    Results: Four-way ANOVA showed significant effects of adhesive application protocol (P=0.000) and storage time (P=0.000) on µSBS. The interaction effect of the two on µSBS was also significant (P=0.046). The µSBS after 24 hours was higher than that after 1 year irrespective of the adhesive application protocol. The µSBS was maximum in the laser group followed by waiting for 30 seconds, and all pairwise comparisons were significant in this respect (P=0.000). Conclusion: In aged composite restoration repair, diode laser irradiation of adhesive prior to polymerization or waiting for 30 seconds prior to adhesive curing can enhance the µSBS.  </div> Composite Resins, Dental Restoration Repair, Shear Strength 262 273 http://jrdms.dentaliau.ac.ir/browse.php?a_code=A-10-819-2&slc_lang=en&sid=1 Zahra Jaberi Ansari zahrajaberiansari@yahoo.com 100319475328460016092 100319475328460016092 No Department of Restorative Dentistry, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Azam Valian avalian14@yahoo.com 100319475328460016093 100319475328460016093 No Department of Restorative Dentistry, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Mahsa Maghsoudlou nejad maghsoudlou.mahsa@gmail.com 100319475328460016094 100319475328460016094 Yes Department of Restorative Dentistry, School of Dentistry, Golestan University of Medical Sciences, Gorgan, Iran.