title: Effect of thermocycling on the bond strength of composite resin to bur and laser treated composite resin.
abstract: The objective of this study was to investigate the effect of two different surface treatments (Er:YAG laser and bur) and three different numbers of thermal cycling (no aging, 1,000, 5,000, and 10,000 cycles) on the micro-shear bond strength of repaired composite resin. Ninety-six composite blocks (4 mm × 4 mm × 1 mm) obtained with a micromatrix hybrid composite were prepared. The composite blocks were then randomly divided into four groups (n = 24), according to the thermal cycling procedure: (1) stored in distilled water at 37°C for 24 h (control group), (2) 1,000 cycles, (3) 5,000 cycles, and (4) 10,000 cycles. After aging, the blocks were further subdivided into two subgroups (n = 12), according to surface treatment. Bur and laser-treated composite surfaces were treated with an etch&rinse adhesive system. In addition, a microhybrid composite resin was bonded to the surfaces via polyethylene tubing. Specimens were subjected to micro-shear bond strength test by a universal testing machine with a crosshead speed of 0 and 5 mm/min. The data were analyzed using one-way analysis of variance and Tukey tests (α = 0.05) for micro-shear bond strengths. After conducting a bond strength test, it was found that the laser and bur-treated specimens had similar results. Aging with 10,000 thermocycles significantly affected the repair bond strength of composite resins.
authors.affiliation: Faculty of Dentistry, Department of Restorative Dentistry, Cumhuriyet University, Sivas, Turkey. ozdenozel@hotmail.com
authors.forename: Özden
authors.initials: Ö
authors.lastname: Özel Bektas
authors.forename: Digdem
authors.initials: D
authors.lastname: Eren
authors.forename: Seyda
authors.initials: S
authors.lastname: Herguner Siso
authors.forename: Gulsah E
authors.initials: GE
authors.lastname: Akin
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry / Q000528:radiation effects*; D000704:Analysis of Variance; D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects*; D001840:Dental Bonding / Q000379:methods*; D003799:Dental Stress Analysis; D006358:Hot Temperature; D053844:Lasers, Solid-State; D008422:Materials Testing; D011140:Polyurethanes / Q000737:chemistry / Q000528:radiation effects*; D033081:Shear Strength / Q000528:radiation effects*
chemical_list: D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; D011140:Polyurethanes