Influence of adhesion on wear resistance of resin-coating materials

Objective: This study examined relationship between tensile bond strength (TBS) and wear-resistance (WR) of two resin-coating materials using toothbrush-abrasion (TA) test.

Methods: Extracted bovine tooth were ground to flat dentin plate with SiC-paper (#180 for TBS, #2000 for TA-test) under water irrigation. Resin-coating materials, Brush&Bond^TM (B&B:Parkell in USA) and SB Coat (SBC:Sun Medical in Japan) were applied to the dentin surface (ø4.8mm for TBS, ø 6mm for TA-test) with and without an air-blow in order to make different film-thickness. The specimens were prepared by combining with composite-resin on the surface coated and measured TBS after immersion in 37 °C water-bath for 24-hour (n=6). Specimens for both film-thickness and TA-test were prepared by removal of non-polymerized monomer-layer on the surface coated. The five-specimen were sliced and measured the film-thickness by SEM. Another five-specimen were mounted in the holder of TA-tester containing toothbrushes(Butler#411). The test of 1000-stroke (total running distance:200m) was carried out under normal load of 1N both with diluted toothpaste.  In order to stain the expose dentin, after every 100-stroke the samples were etched with aqueous solution(pH1) of 10% citric acid and 10% FeCl₃ for 10-second followed by immersing in aqueous 5% tannic acid(pH3.1) for 10-minute.  The WR was estimated from area of the exposed dentin by graphic image analysis. The data were analyzed by ANOVA (p=0.05).

Results: Table showed that TBS of B&B was significantly higher than that of SBC. The WR of B&B demonstrated more than 99% until 1000-stroke when the film-thickness had over 10µm.

Conclusion: This result indicated that the WR depended on both the film-thickness and TBS.