Does Acid Challenge Affect the Properties and Bond Stability of Restorative Materials on Primary Teeth?

Meta-Analysis of In-Vitro Bonding of Glass-Ionomer Restorative Materials to Primary Teeth

Restoration of primary teeth is among the main clinical applications of glass-ionomer cements (GIC). The aim of the study was to review and summarize existing evidence of in vitro bond strength of glass-ionomer (GI) restoratives to enamel and dentin of primary teeth. A literature search was performed in PubMed/Medline, Scopus, Web of Science, Cochrane, and Google Scholar databases to identify studies published until April 2021. The search strategy was: (“glass”) and (“ionomer”) and (“primary” or “deciduous”) and (“bond” or “tensile” or “shear”). Two researchers independently retrieved articles that reported on the bond strength of GIC to primary dentin and/or enamel. The meta-analysis was performed to compare the bond strength values of conventional (C) GIC and resin-modified (RM) GIC to different substrates. From 831 potentially eligible articles, 30 were selected for the full-text examination, and 7 were included in the analysis. Studies were rated at high (3), medium (3), and low (1) risk of bias. RM-GIC showed higher bond strength to primary enamel and dentin compared to the C-GIC. Meta-analysis of in vitro studies, evaluating bonding properties of GI restoratives to primary teeth, suggests the superior performance of RM-GIC. However, there is a lack of studies that examine the properties of novel GI formulations.

Mechanical Characterization of Two Dental Restorative Materials after Acidic Challenge

The aim of this study was to determine the effect of acidic beverages on the mechanical characteristics of a nanofilled composite resin and of a glass ionomer. Thirty specimens of each restorative material were produced and were evaluated at three different time points: before immersion (T0), after a 7 day immersion (T1) and after a 14 day immersion (T2) in water, beer and a soft drink. The studied parameters were microhardness and surface roughness. At T2, composite resin and glass ionomer specimens immersed in water, beer and the soft drink showed a statistically significant decrease in microhardness compared to T0 results. The surface roughness of composite resin specimens decreased between T0 and T1/T2 after immersion in beer and soft drink. A statistically significant increase was found between the roughness of glass ionomer specimens immersed in each one of the beverages at T0 and T1/T2. It is essential that clinicians are aware not only of available restorative materials, its characteristics and best handling techniques but also of the importance of performing an adequate assessment of patients’ dietary habits, thus making it possible to offer patients quality treatments with a predictable prognosis and longevity.