Comparative evaluation of different periods of enamel microabrasion on the microleakage of class V resin-modified glass ionomer and compomer restorations: An In vitro study.

Abstract

The design of the class V cavity presents a clinical challenge in the field of adhesive dentistry as the margin placement is partially in enamel and partly in dentin, and the trouble associated with this design is the microleakage at the dentinal margin. When these restorations undergo microabrasion due to cosmetic reasons, this trouble aggravates to the significant levels. The aim of this study was the measurement of microleakage of class V glass ionomer restorations over two different periods of enamel microabrasion. This in vitro experimental study was conducted on 120 class V cavities which had been prepared on the buccal and lingual surfaces of 60 sound human premolars. One-half of the cavities were restored with the resin-modified glass ionomer cement (GIC) (60 cavities) and another half with the compomer (60 cavities). Finishing and polishing were performed. Then, the teeth were classified into six groups (n = 20). Microabrasion treatment was performed with Opaluster (Ultradent Product Inc., South Jordan, UT, USA) for 0 (control no treatment), 60 and 120 s. Then, teeth were thermocycled between 5°C and 55°C, immersed in rhodamine B solution (24 h), and sectioned longitudinally in buccolingual direction. Dye penetration was examined with stereomicroscope (×10). Microleakage scores were statistically analyzed. The mean occlusal margin scores and gingival margin scores were compared between all the groups using the Kruskal-Wallis test, Mann-Whitney U-test, Wilcoxon signed-rank test, and post hoc comparison. There was a significant difference between Group 1a, Group 2a, Group 1b, Group 2b, Group 1c, and Group 2c. Statistical analysis used in this study was Kruskal-Wallis test, Mann-Whitney U-test, Wilcoxon signed-rank test, and post hoc comparison. The least microleakage scores were observed in occlusal margins of control groups (without microabrasion). Moreover, in both restorations, the microleakage scores in occlusal margins were higher than gingival margins, and compoglass had less microleakage in occlusal and occlusal plus axial walls of class V cavities compared with resin-modified GIC. Whereas, the light-cured glass ionomer had less microleakage in the gingival and gingival plus axial walls of class V cavities when compared with compoglass. The least microleakage scores were observed in occlusal margins of control groups (without microabrasion). Moreover, in both restorations, the microleakage scores in occlusal margins were higher than gingival margins.