Glass ionomer based materials are clinically popular in several areas of restorative dentistry, but restoration of cervical lesions has proven particularly successful. Various etiologies, conformations, locations and structural characteristics make non-carious cervical lesions more challenging to adhesive restorative procedures and marginal seal in the long run. Due to their characteristics, glass ionomer cements (GICs) have precise indication for these cases. Moreover, the use of a GIC base underneath composite resin, the so-called "sandwich" or mixed technique, allows associating the good characteristics of composite resins and GICs, and has been considered quite useful in the restoration of non-carious cervical defects. The aim of this paper is to critically review the literature and discuss peculiar features of GICs regarding their role in the restoration of non-carious cervical lesions.

Several studies have investigated the effect of bleaching on dental tissues. The evaluation of the effect of home bleaching with 10% carbamide peroxide is important for assessing alterations in enamel microhardness that may affect dental health in terms of resistance to masticatory forces. This meta-analysis was performed in order to determine scientific evidence regarding the effects of home vital bleaching with 10% carbamide peroxide gel on the microhardness of human dental enamel. A systematic electronic literature search was conducted in the PubMed and Web of Science databases using search terms. Two independent researchers evaluated the information and methodological quality of the studies. Inclusion and exclusion criteria were established for article selection; further, only studies published in English were selected. Thirteen studies that met all of the inclusion and exclusion criteria were selected and underwent statistical analysis. The results of this meta-analysis showed no significant changes in enamel microhardness when using the 10% carbamide peroxide bleaching gel over periods of 7, 14 and 21 days.

During post preparation, the root canal is exposed to the oral cavity, and endodontic treatment may fail because of coronal leakage, bacterial infection and sealing inability of the luting cement.Objectivethis study quantified the interfacial continuity produced with conventional dual-cure and self-adhesive resin cements in the cervical (C), medium (M) and apical (A) thirds of the root. Material and methodsForty single-rooted human teeth were restored using Reforpost # 01 conical glass-fiber posts and different materials (N=10 per group): group AC=Adper™ ScotchBond™ Multi-purpose Plus + AllCem; group ARC=Adper™ ScotchBond™ Multi-purpose Plus + RelyX ARC; group U100=RelyX U100; and group MXC=Maxcem Elite. After being kept in 100% humidity at 37ºC for 72 hours, the samples were sectioned parallel to their longitudinal axis and positive epoxy resin replicas were made. The scanning electron micrographs of each third section of the teeth were combined using Image Analyst software and measured with AutoCAD-2002. We obtained percentage values of the interfacial continuity. ResultsInterfacial continuity was similar in the apical, medium and cervical thirds of the roots within the groups (Friedman test, p>0.05). Comparison of the different cements in a same root third showed that interfacial continuity was lower in MXC (C=45.5%; M=48.5%; A=47.3%) than in AC (C=85.9%, M=81.8% and A=76.0%), ARC (C=83.8%, M=82.4% and A=75.0%) and U100 (C=84.1%, M=82.4% and A=77.3%) (Kruskal-Wallis test, p<0.05). ConclusionsAllcem, Rely X ARC and U100 provide the best cementation; cementation was similar among root portions; in practical terms, U100 is the best resin because it combines good cementation and easy application and none of the cements provides complete interfacial continuity.

A self-adhesive resin cement can provide a significantly stronger bond than a three-step etch-and-rinse adhesive and resin cement when used to lute fiber posts. SUMMARYThe bond strength of fiber posts luted with resin cements was evaluated after two storage times in different regions of a post space. A total of 40 single-rooted human teeth were endodontically treated and prepared for cementation of fiber posts (White Post DC). In groups 1 and 3 (G1 and G3, respectively), posts were luted with RelyX ARC, whereas the posts in groups 2 and 4 (G2 and G4, respectively) were luted with RelyX Unicem. After one month of storage at 100% humidity, G1 and G2 were transversally sectioned in 1.7-mm slices of the cervical (C), middle (M), and apical (A) thirds of the post space and submitted to push-out testing at 1 mm/min. After nine months of storage, the roots of G3 and G4 underwent the same process. Mean values were analyzed using the Mann-Whitney and Kruskal-Wallis tests (a¼0.05). The bond strengths in G2 (C¼4.2662.29; M¼4.6763.54; A¼7.2764.30) were statistically higher than in G1 (C¼3.8161.07; M¼1.5761.62; A¼1.9961.60) in the middle and apical thirds (p¼0.001). Bond strengths in G4 (C¼3.3661.39; M¼4.4962.17; A¼3 . 8 361 . 9 2 ) w e r e h i g h e r t h a n i n G 3 (C¼2.1360.47; M¼0.9461.05; A¼0.9561.02) in all evaluated regions ( p¼0.02, p,0.001, and p,0.001, respectively). When comparing the root regions for each group, G1 had higher , 2011, 36-6, 643-648 values in the cervical third than the middle third (p¼0.02). The self-adhesive resin cement showed better results than the conventional resin cement at both storage times. For both materials a similar performance among the three root regions was found. Storage time did not influence the shear bond strength.

Context:The food wrap films are used to cover the tip of curing light units in order to avoid contamination and prevent damage to the light guide. However, their effects on resin polymerization are not fully known.Aims:We investigated the effects on restoration efficiency of a food wrap protective barrier used on the tip of curing light units.Materials and Methods:For each treatment, five replications were performed, a total of 60 bovine incisor. The degree of conversion (%DC) of restorations with the composite resin Opallis EA2 was evaluated using 3 curing light devices (Optilux 501, Optilight and Ultra LED) and 2 curing distances (0 and 5 mm). The composite resin was tested for restoration of cavities in bovine crowns. %DC values were measured by the Fourier transform infrared spectroscopy-attenuated total reflectance technique.Statistical Analysis Used:The data were analyzed using 3-way ANOVA and Tukey's test.Results:Use of the protective film lowered %DC (F = 4.13; P = 0.05), and the effects of curing distance were associated to the curing light device (F = 3.61; P = 0.03).Conclusions:The distance from the light curing tip and use of a translucent protective barrier on the light-cure device can both impair composite resin %DC.