اثر فشار پالپی بر استحکام ریز کششی کامپوزیت به عاج تراش داده شده با لیزر

Abstract

Background and aim: Bonding to dentin with adhesive systems is affected by the tubular fluid flow induced by pulpal pressure. The aim of this study was to evaluate the effect of simulated pulpal pressure on the microtensile bond strength of adhesives to dentin surface which is prepared by laser irradiation.

Materials and methods: Twenty extracted human third molars were selected for this study. The crowns of teeth were separated from the roots. Samples were subjected to Er,Cr:YSGG laser irradiation at 2W (22.4 J/cm2 ) energy density under continuous 20% air spray and 15% water spray. In group one, resin composite (Z-250 Filtek) was bonded to flat surfaces of samples using dentin bonding agent (Single Bond) under simulated pulpal. Same procedure was done for second group without pulpal pressure simulation. After saline solution (37˚C, 24 hours) , 1mm thick slices were cut from samples. Microtensile bond strength was determined. Statistical significance was determined by T-test (p<0.05).

Results: Mean microtensile bond strength (MPa ± SD) in first group (15.3±4.3) was lower than second group (23.7±8) significantly (p<0.0005).

Conclusion: Simulated pulpal pressure had a negative effect on micro tensile bond strength of laser ablated dentin when Single Bond adhesive system was used.