Effect of Various Etching Techniques on Shear Strength of Newer Generation Composites

To evaluate the effect of lasers on the shear bond strength of Giomer and G-aenial flo composite using three different etching techniques.

60 Samples (extracted human premolar teeth) are cut horizontally using a diamond disk to expose a flat occlusal surface involving enamel and dentin. On exposed occlusal surfaces, etching is done by various methods. These were divided into six groups of ten samples each as follows: group I (acid etched for Giomer), group II (acid etched for G-aenial flo composite), group III (laser etched for Giomer), group IV (Laser etched for G-aenial flo composite), group V (air abrasion etched for Giomer), group VI (Air abrasion etched for G-aenial flo composite). Then, restorative material is placed and cured with light for 20 seconds. The samples were thermocycled to simulate the oral environment. The samples were subjected to a universal testing machine for bond strength testing at a cross-head speed of 3 mm/min until the restoration will fracture.

The intergroup comparison between both the materials using Student's t-test gives insignificant results. The intergroup comparison between different etching techniques using two-way ANOVA tests gives insignificant results.

Within the limitation of this study, it can be concluded that Giomer and G-aenial flo composite achieved the same shear bond strength in all the etching techniques.