Repair bond strength of nanohybrid composite resins with a universal adhesive

摘要

Objective: To investigate the repair bond strength of fresh and aged nanohybrid and hybrid composite resins using a universal adhesive (UA).Materials and methods: Fresh and aged substrates were prepared using two nanohybrid (Venus Pearl, Heraus Kulzer; Filtek Supreme XTE, 3?M ESPE) and one hybrid (Z100, 3?M ESPE) composite resin, and randomly assigned to different surface treatments: (1) no treatment (control), (2) surface roughening with 320-grit (SR), (3) SR?+?UA (iBOND, Heraus Kulzer), (4) SR?+?Silane (Signum, Ceramic Bond I, Heraeus Kulzer) + UA, (5) SR?+?Sandblasting (CoJet, 3?M ESPE) + Silane?+?UA. After surface treatment, fresh composite resin was added to the substrates at 2?mm layer increments to a height of 5?mm, and light cured. Restored specimens were water-stored for 24?h and sectioned to obtain 1.0?×?1.0?mm beams (n ?=?12), and were either water-stored for 24?h at 37?°C, or water-stored for 24?h, and then thermocycled for 6000 cycles before microtensile bond strength (μTBS) testing. Data were analyzed with ANOVA and Tukey’s HSD tests (p ?=?.05).Results: Combined treatment of SR, sandblasting, silane and UA provided repair bond strength values comparable to the cohesive strength of each tested resin material (p ??.05). Thermocycling significantly reduced the cohesive strength of the composite resins upto 65% (p ??.05). Repair bond strengths of UA-treated groups were more stable under thermocycling.Conclusions: Universal adhesive application is a reliable method for composite repair. Sandblasting and silane application slightly increases the repair strength for all substrate types.