Influence of contamination by handpiece lubricant spray on bond strength between auto-cured resin and denture base resin

Abstract

This study evaluated the effect of contamination by handpiece lubricant spray on the microtensile bond strength (μTBS) of bonded denture base resins. We also investigated the effects of various surface pre-treatments on the recovery of μTBS. Denture-based MMA resin was polymerized and shaped into 12 x 12 x 7 mm blocks. One side of the cut surfaces was abraded using #120 SiC paper and contaminated with lubricant spray. After applying 14 different surface treatments to each contaminated surface, blocks were bonded using auto-cured MMA resin and compared with an uncontaminated control. The lubricant spray-contaminated group showed significantly lower μTBS (23.4±5.3 MPa) than the uncontaminated control (58.3±5.4 MPa；p＜0.05). Only groups with soaking or ultrasonic cleansing in aqueous solution of sodium bicarbonate or ultrasonic cleansing in commercial denture cleaner showed recovery of μTBS to the same level as or higher than the uncontaminated control.