Effect of bur type on bond strengths of adhesive systems to enamel. W.R.L. DIAS,* P.N.R. PEREIRA, and E.J. SWIFT, Jr. (Department of Operative Dentistry, University of North Carolina, Chapel Hill, NC).
The development of self-etching primers (SEP) and one-step self-etching adhesives (SEA) introduced new alternatives for bonding; however, concern remains about their efficacy on enamel prepared with different high-speed burs. Objective: The purpose of this study was to compare the microtensile bond strength (mTBS) of three adhesives to bovine enamel prepared with 600-grit SiC paper (SiC), diamond stone (DS), or carbide bur (CB). Methods: Bovine teeth (n=27) were randomly divided into three treatment groups and bonded using a total-etch adhesive (Single Bond, 3M ESPE), SEA (One-Up Bond F, Tokuyama) or SEP (SE Bond, Kuraray). A 4-mm composite crown was built over the bonded surfaces and stored in water for 1 day at 37°C. Specimens were sectioned into 0.7-mm thick slabs, trimmed to a cross-sectional area of 1 mm2, and loaded to failure at crosshead speed of 1 mm/min using a table top tester (EZ-Test). Data were analyzed using ANOVA and Fisher’s PLSD test (p<0.05). Values are expressed as mean ± SD (in MPa).
| Adhesives/Treatment | SiC | Diamond | Carbide |
| Single Bond | 38.1±12.5a | 32.1±3.6a | 37.6±8.8a |
| One-up Bond | 31.6±8.3a | 21.4±3.7b | 21.3±5.3b |
| SE Bond | 51.3±7.7c | 35.5±8.8a | 30.8±9.2a |
Same superscripts indicate no statistical significant difference (p>0.05). Results: None of the adhesives had significantly different mTBS to bovine enamel prepared with carbide or diamond. SEP and SEA had higher mTBS when substrate was prepared with 600 grit silicon-carbide papers, nevertheless this didn’t seem to affect the performance of the total-etch system used in this study. Conclusion: Clinicians should be aware that different bur types commonly used for cavity preparations might not affect the performance of adhesives on enamel. This study was supported by Kuraray Medical.