Effects of various irrigation solutions on microleakage of Class V composite restorations

Irrigation solutions used in the preparation of composite restorations have been reported to contain potential contaminants that may interfere with, and compromise, composite bonding.

The purpose of this in vitro study was to evaluate microleakage of Class V composite restorations after irrigation of acid conditioner with various solutions. MATERIAL AND MENTODS: Standardized Class V preparations (5 mm wide, 4 mm high and 2 mm deep) were made at the cemento-enamel junction on available buccal, lingual, mesial, and distal surfaces of extracted human posterior teeth. The prepared teeth, separated into 7 groups (n=10), were etched for 10 seconds with a 37% phosphoric acid gel. Each group was irrigated with 1 of the following solutions: (1) tap water, (2) sterile water, (3) sodium chloride solution, (4) filtered water, (5) chlorhexidine, (6) sodium hypochlorite, and (7) distilled water. Each preparation was treated with a bonding agent (Opti-Bond Solo) and then restored with a hybrid composite (Herculite XRV). The restorations were polished with Soflex polishing disks and then thermal cycled for 1000 cycles between 5 degrees C and 55 degrees C with a 20-second dwell time. Assessment of microleakage was performed by application of a dye penetrant, sectioning of the teeth, and examination at original magnification x 20. The nonparametric Kruskal-Wallis test (alpha=.05) was used for statistical analysis.

Microleakage ranging from 10% to 30% was observed in all groups tested. Tap water exhibited the highest incidence of leakage, sterile water the least, with the other irrigation solutions leading to intermediate leakage. However, there was no significant difference in microleakage resulting from any of the irrigation solutions tested.

The effect of irrigation solutions used in this in vitro study was not significant.