Investigation of bond strength of silicone based soft lining material to denture base material on the surfaces treated by sandblasting and laser methods

Adhesion failure between silicone-based resilient lining materials and PMMA is a commonly encountered problem in clinical practice. Adhesion failure between two materials results in localized unhygienic conditions at the debonded regions and often causes functional failure of the prosthesis.The aim of the study is to investigate the effect of different surface roughening procedures that were applied on denture base on adhesion of Molloplast-B soft relining material to PMMA.Treatment with Er: YAG laser and sandblasting by aluminum particles in two different dimensions were choosen raughening procedures.To determine the adhesion between Molloplast-B and PMMA, due to the smilarity with the forces that exist in oral environment peel and shear bond strength tests were applied. Before the tests, all samples were applied thermalcycling procedure 500 times between +5 and +55ºC.Mean rougheness value obtained from laser was (6.23 µm) 2.5 - 3 times more than sandblasting. In control and laser groups bond strength values were lower. The highest peel bond strength was obtained from sandblasting with 50 µm alumino particles and the highest shear bond strength was obtained from sandblasting with 250 µm alumino particles.As a result of the study while surface roughness formed by sandblasting increased the adhesion between Molloplast-B and PMMA, although the rougheness formed by laser was more than the other groups, against the will laser treatment degreased the bond strength.Key words: Molloplast-B, Er: YAG laser, peel bond strength, shear bond strength