Microleakage of cervical restorations etched with a weak organic acid.
This in-vitro study evaluated the microleakage of Class V restorations prepared using 10 per cent maleic acid and a composite resin. Thirty human premolar teeth were evenly distributed and randomly assigned to three groups. Conventional retentive preparations, etched with 10 per cent maleic acid for either 15, 30, or 60 seconds, were cut in the enamel on the facial surface of each tooth to a 1.5 mm depth (dentin). All teeth were restored with Z-100, a small particle composite resin. The teeth were then stored in deionized water for seven days, thermocycled, stained with methylene blue dye, invested, and sectioned vertically through the centre of the restoration. Leakage was established along each wall of the sectioned restoration. Analysis of variance (ANOVA) tests indicate that the restored teeth in Group 1 (15-second etch) had significantly greater microleakage (p < 0.05) on the enamel wall than the restored teeth in Group 2 (30-second etch) or Group 3 (60-second etch). In addition, Group 1 restorations had significantly greater overall microleakage (p < 0.05) than Group 2 or Group 3 restorations. Although the results were not statistically significant, it would appear that etching with 10 per cent maleic acid for 30 seconds could be clinically significant. Since a 30-second etch time was found to produce the least amount of microleakage (not statistically significant), it can be assumed that this etch time would also be optimal for etching enamel and dentin. Similarly, since Group 1 revealed the most overall microleakage, it can be assumed that a 15-second etch would be inadequate for etching enamel and dentin. Restorations in Groups 2 and 3 displayed statistically significant lower overall microleakage results.
Owens
B M
BM
Department of General Dentistry, University of Tennessee, College of Dentistry, Memphis 38163, USA.
D000134:Acid Etching, Dental / Q000379:methods*; D000704:Analysis of Variance; D001641:Bicuspid; D004396:Coloring Agents; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding / Q000379:methods; D003743:Dental Enamel / Q000473:pathology; D003763:Dental Leakage / Q000175:diagnosis*; D003793:Dental Restoration, Permanent / Q000145:classification*; D003804:Dentin / Q000473:pathology; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D008298:Maleates / Q000008:administration & dosage* / Q000737:chemistry; D008751:Methylene Blue; D019279:Resin Cements; D012822:Silicon Dioxide; D013816:Thermodynamics; D013997:Time Factors; D019237:Tooth Cervix / Q000473:pathology*; D015040:Zirconium
D004396:Coloring Agents; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008298:Maleates; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C083568:Z100 composite resin; D012822:Silicon Dioxide; C030272:maleic acid; D015040:Zirconium; D008751:Methylene Blue