Full Length Research Paper

Effect of simulated pulpal pressure on composite bond strength to dentin prepared using Er, Cr: YSGG laser

Siavash Savadi Oskoee, Parnian Alizadeh Oskoee, Soodabeh Kimyai*, Narmin Mohammadi and Sahand Rikhtegaran

Department of Operative Dentistry, Faculty of Dentistry, Tabriz University, Medical Sciences, Tabriz, Iran.

*Corresponding author. E-mail: kimyais@tbzmed.ac.ir. Tel: 0098411- 3340310. Fax: 0098411-3346977.

Accepted 21 September, 2009

   Abstract

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 an adhesive to dentin surface prepared by laser irradiation. Crowns of twenty human extracted third molars were subjected to Er, Cr: YSGG laser beams. Specimens were divided into two groups according to pulpal pressure simulation. In the first group resin composite (Z-250 Filtek) was bonded to flat surfaces of samples using dentin bonding agent (Single Bond) under simulated pulpal pressure. In the second group, the same procedure was carried out without pulpal pressure simulation. After storing the teeth in saline solution at 37˚C for 24 h, thirty 1-mm-thick slices were cut from the samples in each group and subjected to bond strength test. Microtensile bond strength was determined using a universal testing machine at a crosshead speed of 2 mm/min. Statistical significance was determined by T-test (p < 0.05). There was a statistically significant difference in the mean microtensile bond strengths between the groups (p < 0.0005). Simulated pulpal pressure had a negative effect on microtensile bond strength of laser ablated dentin when Single Bond adhesive system was used.

Key words: Bond strength, laser treatment, pulpal pressure, resin composite.