dental materials 32S (2016) e1–e103 e5 Fig. 1 Conclusions: Within the limitations of this study, Bluephase Meter II met the manufacturer’s claim and accurately measured the power output of tested LCUs. http://dx.doi.org/10.1016/j.dental.2016.08.008 8 The influence of FRCs positioning underneath CAD/CAM composite resins C.M. Saratti 1,∗ , M. Cattani-Lorente 1 , R. Sadlaceck 2 , G.T. Rocca 1 , I. Krejci 1 1 University of Geneva, Switzerland 2 University of Prague, Czech Republic Purpose/Aim: Investigate the reinforcing and stress- breaking effects of long bidirectional E-glass fiber reinforced composites (FRCs) applied underneath CAD/CAM resin com- posites. Materials and methods: A total of 120 specimens (9 mm × 5 mm, 4.2 mm-thick) were prepared. Specimens were divided in four Groups (n = 30): monolithic CAD/CAM resin composite (Cerasmart, GC) (Group A, control), composite resin base (Genial Posterior, GC) in a layer of 1 mm (Group B), 2 mm (C) and 3 mm (D) underneath two bonded layers of bidirec- tional e-glass FRC (Dentapreg, ADM A.S.). Over these FRCs sheets, CAD/CAM composite resin slices of 3 mm (Group B), 2 mm (C), 1 mm (D) were bonded. In each group, half of the specimens (n = 15) (Subgroups As, Bs, Cs, Ds) were loaded to fracture in a universal testing machine. Maximum frac- ture loads were recorded in Newtons and data were analyzed using Weibull analysis. The other half of specimens of each group (n = 15) (Subgroups Ad, Bd, Cd, Dd) were submitted to cyclic isometric stepwise loading (5 Hz) until completion of 105,000 cycles or failure after 5000 cycles at 500N, followed by stages of 20,000 cycles at 750 N, 1000 N, 1250 N, 1500 N and 1750 N. Results were statistically analyzed by Kaplan–Meier life survival analysis and log rank test (p = 0.05). All fractured specimens were analyzed using stereomicroscope and SEM and modes of failure were determined (vertical fracture-split, partially deviated fracture or completely deviated fracture). Results: The mean static loads (N) registered were: A – 2904.13 (159.33); B – 2716.55 (307.14); C – 2539.96 (153.17); D – 2263.17 (167.96). Statistically significant differences were found between all groups (p < 0.05). The differences in sur- vival after fatigue between groups was statistically significant, except between Groups A and C (p = 0.86213). The mode of fracture was always catastrophic (split) in Group A (without fibers) while in Groups B and C the crack was mainly par- tially deviated, and in Group D it was mostly totally deviated, with few differences between fractures occurred under static or dynamic loads. In all deviated fractures, the fractographic analysis confirmed the stress-breaking effect of the FRCs layer. Conclusions: The load bearing capacity of the specimens and their fatigue resistance seemed to be more related to the thickness of the CAD/CAM resin composite under the loading sphere more than to the subjacent FRCs layer. However, the fiber reinforcement protected the resin composite substruc- ture leading to more favorable fracture patterns. http://dx.doi.org/10.1016/j.dental.2016.08.009 9 Wear evaluation of dental Y-TZP opposing human enamel S. Passos 1,∗ , Y. Torrealba 1 , B. Linke 1 , C. Flores-Mir 1 , J.A. Nychka 2 1 University of Alberta, School of Dentistry, Edmonton, Canada 2 University of Alberta, Department of Chemical and Materials Engineering, Edmonton, Canada Purpose/Aim: The aim of this systematic review was to assess enamel wear on teeth opposing zirconia restorations by analyzing in vitro studies that quantify the wear of enamel opposing zirconia ceramics. Additionally to evaluate factors related to the wear of the natural tooth opposing zirconia ceramics. Materials and methods: Five electronic databases were searched without limitations. Terms “antagonist*”, “enamel”, “wear” and “zirconi*” were used. All titles revealed by the electronic search were screened according to the following inclusion criteria: (1) In vitro studies; (2) Use of Y-TZP ceramic;