The Effect of Different Silica Coating Techniques on Bond Strength of Resin Cement to Ultra-translucent Zirconia

Abstract

his study was performed to evaluate the effect of different silica coating techniques which were: tribochemical silica coating technique, silica containing materials on shear bond strength between ultra-translucent zirconia and conventional resin cement. Ultra-translucent zirconia samples (18 mm width×18mm length ×3 mm thickness) were prepared by cutting Bruxzir anterior block using a diamond disk mounted on Isomet 4000 microsaw. After that, samples were sintered according to the manufacturer's instructions. Then finished using sandpaper 400 and 1200 grit and ultrasonically cleaned in distilled water for 10 minutes. Three different surface treatment methods were applied to zirconia surfaces in this study. These methods were: tribochemical silica coating, and the application of two silica containing materials. In tribochemical silica coating, the surface of ultra-translucent zirconia samples was bombarded with silicatized sand particles which resulting in coating the surface with silica. The two silica containing materials were also applied: sodium silicate solution and tetraethyl orthosilicate so-gel. Three techniques were applied to post sintered ultra-translucent zirconia (after sintering). On sample from each group was examined for surface morphology using SEM and elemental surface composition using EDX. Silane coupling agent was applied on all silica coated ultra-translucent zirconia samples for one minute. Then, the samples were dried for 10 seconds with oil\water free compressed air. Small transparent tubes were cut from polyvinyl tube (catheter) with (4 mm inner diameter, 3 mm height and 2 mm thickness) was positioned at the center of each specimen. The tubes were attached to zirconia samples using a bonding agent. Each tube was held by tweezers and coated at one end with the bonding agent using a microbrush. Then the tube was put on the ultra-translucent zirconia sample. A light emitting diode curing unit of high intensity 1500 mW\cm2 was used to cure the bonding agent for 20 seconds.