Ozcan, MutluCura, CenkBrendeke, Johannes2019-10-272019-10-2720101461-51851757-9988https://doi.org/10.3290/j.jad.a17857https://hdl.handle.net/11454/45263Purpose This study evaluated the effect of different aging methods on the repair bond strength and failure types of a microhybrid and a nanohybrid composite Materials and Methods Disk shaped microhybrid (Quadrant Anterior Shine-QA) and nanohybrid (Tetric EvoCeram TE) resin composite specimens (N = 192, n = 12/per group) were photopolymerized and randomly assigned to one of the three aging conditions (1) immersion in deionized water (37 degrees C 2 months) (2) thermocycling (5000 times 5 to 55 degrees C) (3) immersion in citric acid (pH 30 1 week) The control group was stored dry for 24 h at 37 degrees C After aging procedures, the specimens were silica coated (30 mu m SiO2) (CoJet Sand) using an intraoral air abrasion device, silanized (ESPE Sil) and an intermediate adhesive resin was applied (Vivo Bond 3M ESPE) Resin composites, once of the same kind as the substrate (QA QA, TE TE) and once other than the substrate material (QA TE TE-QA) were adhered onto the con damned substrates Shear force was applied to the adhesive interface in a universal testing machine (cross head speed 1 mm/min) Results A significant influence of the aging method was observed (p < 0 05) but the composite type did not affect the repair bond strength (p = 0 755) (2 way ANOVA Tukey s test) Interaction terms were significant (p < 0 05) Thermocycling showed lower results (10 +/- 2 6 to 14 4 +/- 4 4 MPa) than those of other aging methods (12 7 +/- 5 2 to 28 +/- 5 3 MPa) Using the substrate and the adherend interchangeably (QA TE, TE QA) did not show significant differences in the control group but the results were significant after aging (p = 0 007) (2 way ANOVA Tukey s test) Interaction terms were not significant (p = 0 124) The incidence of score A (cohesive failures in the substrate) was not significant between the composite combinations in the control groups (exclusively 100%) and water storage aged groups (92% to 100%) (p > 0 05) (chi square) Citric acid aging yielded significantly less incidence of score A (8 75%) compared to the control group in all composite combinations (p < 0 05) Conclusion Both microhybrid and nanohybrid composites could be used either as a substrate or as relayering composites in early repairs Aging factors may diminish the repair qualityen10.3290/j.jad.a17857info:eu-repo/semantics/closedAccessagingmicrohybrid compositenanohybrid composite repairsilica coating surface conditioningArticle126451459WOS:00028544070000520157647Q2