Surface treatment with ascorbic acid and ferric chloride improves the micro-tensile bond strength of 4-META/MMA-TBB resin to dentin

Objective The purpose of this study was to investigate the efficacy of an experimental dentin conditioner consisting of ascorbic acid (AA) and ferric chloride (Fe), in terms of micro-tensile bond strength (μTBS). Methods Five experimental solutions were prepared and evaluated: 10% AA and 5% Fe (10AA–5Fe); 10% AA and 0% Fe (10AA–0Fe); 0% AA and 5% Fe (0AA–5Fe); 10% citric acid and 3% ferric chloride (10–3); and, 0% AA and 0% Fe (0AA–0Fe). Flattened dentin surfaces were treated with each of the experimental solutions. A composite material rod was bonded to the dentin surface with a self curing luting agent (4-META/MMA-TBB resin). The specimens were stressed to failure under tension after 24 h of immersion in water. Results The 10AA–5Fe group showed significantly higher bond strength than the 10AA–0Fe, 0AA–5Fe, 10–3 and AA–0Fe groups. Conclusion It was found that an experimental conditioner consisting of 10% ascorbic acid and 5% ferric chloride significantly improved the micro-tensile bond strength between 4-META/MMA-TBB resin and dentin.