An Investigation on Dentin Surface Characterization Changes and Nano-Leakage of Two Different Universal Adhesives

Abstract

This in-vitro study was conducted on two different universal adhesives applied in both E&R and SE modes to investigate: a- Changes in surface characterization of dentin and b- Resin/dentin interface nano-leakage. A total of 70 dentin specimens were retrieved from 18 non-carious, non-restored human molar teeth for this study. After extraction, the teeth were cleaned from blood and soft tissues were removed using hand scaler. Hard deposits were removed using ultrasonic scaler. The teeth were stored in distilled water at 4⁰C for no more than 3 months. Distilled water was changed every 48 hours during the storage period.

For AFM evaluation 8 teeth were used; the roots of each tooth were cutoff at the CEJ. Each tooth was sectioned into 2 halves mesio-distally. Each half was re-sectioned again into approximately equal 2 halves in the direction occluso-cervically., resulting in 4 quadrants per each tooth, with total of 30 quadrants. The quadrants were randomly assigned into 6 groups, two control groups (n=10) and four experimental groups (n=20). The ten quadrants for the control groups were sub-divided into two groups (n=5/group) according to the intervention done; group 1: no acid etching and group 2: after application of acid etching. While the twenty quadrants for the experimental groups were sub-divided into four groups (n=5/group) according to two experimental factors investigated: Factor 1: Adhesive type; 2 groups and Factor 2: Application mode; 2 groups.