تقييم مقاومة قوى القص لارتباط نظام الكمبوزت المرمم الى خزف الزيركون مع التخزين في الماء والدورات الحرارية او من دونها (دراسة مخبرية)

Background & Objective: to evaluate the shear bond strength(SBS) of a composite resin repair system to zirconia-ceramic with and without water storage and thermo-cycling (WSTC). Materials & methods: Forty eight zirconia ceramic cylinders were fabricated, polished. Then were divided into 3 equal groups (n=16) according to the surface treatments: SB-Sandblasting with 50 µm aluminum oxide (Al3O2) particles; HF - 9.% hydrofluoric acid etch for; and PH – 37% phosphoric acid.Then Ivoclar/Vivadent Ceramic Repair system was applied to the bonding area. Eight specimens from each group were tested for (SBS). The remaining specimens were tested after (WSTC). Results: The (mean±SD) values (Mpa) for non WSTC of zirconia-composite specimens were (SB-10.46 ± 1.41a; HF- 9.44 ± 1.45; and PH- 6.49 ± 0.72. For (WSTC) specimens the (mean±SD) were: SB- 7.93 ± 2.27; HF-6.97 ± 2.23; and PH- 3.82 ± 3.66. The SBS of SB and HF surface treatment statistically higher P<0.05. However (WSTC) reduced the SBS and HF values, whereas there is no statistically differences in the PH groups P>0.05. Conclusions: Sandblasting or HF etch increased the SBS of composite repair system bond to the surface of a zirconia-ceramic. The (WSTC) had negative effects to this bond.