Influence of acid etching on shear strength of different glass ionomer cements

ABSTRACT

Aim: To assess the influence of dental etching on the shear strength of different glass ionomer cements. Methods: The crown of 60 bovine incisors was prepared to obtain a flat, smooth surface, were attached to a PVC tube and randomly divided into six groups Group 1 – Riva Self Cure without etching; Group II – Riva Self Cure with pre-etching; Group III – Maxxion R without etching; Group IV – Maxxion R with pre-etching; Group V – Ketac™Molar Easymix without etching; and Group VI – Ketac™Molar Easymix with pre-etching. Etching was performed with 10% polyacrylic acid for 30 s. A standardizing device was used for preparation of the test specimens (SBS Test Method). Following preparation, the specimens were stored in distilled water at 37º Cfor 24 h. The shear test was performed on a Kratos universal testing machine at a crosshead speed of 0.5 mm/min. The specimens were then viewed under a stereomicroscope at a magnification of x90 for analysis of fractures. Results: The results revealed that pre-etching increased the shear strength of Riva glass ionomer cement (SDI) alone, where as no statistically significant differences were found with regard to the other materials tested. Conclusions: Pre-etching with 10% polyacrylic acid for 30 s increased the shear strength of Riva glass ionomer cement.