Effect of light-cured filled sealant on shear bond strength of metal and ceramic brackets bonded with a resin-modified glass ionomer cement

Introduction Our objective was to evaluate the effects of a highly filled light-cured sealant (HFLCS) on the shear bond strength and bond failure site of metal and ceramic brackets bonded with resin-modified glass ionomer cement (RMGIC). Methods Eighty freshly extracted maxillary premolars were randomly divided into 4 groups (20 in each group). In all groups, the teeth were etched with 37% phosphoric acid for 20 seconds, and RMGIC (Fuji Ortho LC, GC Europe, Leuven, Belgium) was used for bracket bonding. In groups 1 and 3, the brackets were bonded directly to etched enamel surfaces; in groups 2 and 4, the etched enamel was covered with HFLCS (Pro Seal, Reliance Orthodontic Products, Itasca, Ill). Groups 1 and 2 received metal brackets, and groups 3 and 4 had ceramic brackets. The specimens were stored in distilled water at room temperature for 24 hours and subsequently tested in shear mode with a universal testing machine. After debonding, the teeth and the brackets were examined under a stereomicroscope (model SMZ-1B, Nikon, Osaka, Japan) at 20-times magnification to assess the residual adhesive on the tooth surfaces. Results: Interaction between HFLCS and bracket type was not statistically significant ( P = 0.15). Pretreatment with HFLCS did not cause a statistically significant change in the shear bond values of either metal or ceramic brackets ( P = 0.38). Shear bond values of the ceramic brackets were higher than those of the metal brackets independent of HFLCS application ( P