Laboratory evaluation of the A.R.T. bonding system.

Purpose: To determine (1) the in vitro shear bond strengths of the A.R.T. Bond System to dentin at different time intervals, (2) the quantitative microleakage of Class V preparations in dentin restored with the A.R.T. Bond System, and (3) the resin penetration into the dentin tubules by scanning electron microscopy.

Materials And Methods: The occlusal surfaces of 75 extracted human mandibular and maxillary permanent first and second molars were ground wet on 600-grit SiC to expose the superficial dentin. The A.R.T. Primer and the A.R.T. Adhesive were applied to demarcated bonding sites as recommended by the manufacturer. Brilliant Dentin resin composite was transferred to the opening in a split Teflon mold in the assembly apparatus in three increments, each compressed firmly and cured for 40 seconds. Fifteen specimens were disassembled 60 seconds after final cure and then tested. The remaining 60 teeth were disassembled 15 seconds after cure; one group was tested at this time and the others immersed in saline at 37 degrees C for 24 hours, 1 week and 4 weeks before being tested. A shear load was applied at a crosshead speed of 0.5 mm/minute, the shear bond strengths calculated and expressed in MPa. Data were analyzed by ANOVA and Student Newman-Keuls test. Class V cavities were prepared at the facial surfaces of 18 extracted human permanent premolars and restored. Microleakage was determined quantitatively by a spectrophotometric dye-recovery method and expressed as mg dye/restoration.

Results: Mean +/- SD of the shear bond strength in MPa were 13.07 +/- 3.59 (1 minute), 16.08 +/- 3.12 (15 minutes), 18.17 +/- 3.44 (24 hours), 17.54 +/- 5.35 (1 week), 17.90 +/- 2.61 (4 weeks). The mean +/- SD microleakage was 0.008 +/- 0.04 mg dye/restoration.