Microleakage and wall adaptation of conservative restorations

To evaluate the microleakage and wall adaptation of different restorative materials in sealed and unsealed conservative restorations after storage in an acid environment.

100 conservative cavity preparations were prepared in the occlusal surface of 50 non-carious, extracted human permanent molar teeth. The teeth were divided into 5 groups and restored with either flowable compomer, compomer, amalgam, resin-based composite or non-bonded resin-based composite (control). One half of the restorations in each group was sealed with a light cured unfilled sealant material, while the other half was left unsealed. The teeth were placed in artificial saliva for 30 days, radiographed, thermocycled 500 times, placed in an artificial caries solution, immersed in dye, sectioned three times, and recorded at x60 magnification. Three independent examiners assessed each of the 300 recorded sections for leakage and assessed each radiograph for wall adaptation using a slide projector. Kruskal Wallis and Mann-Whitney nonparametric tests were used to analyze the results.

Sealed restorations showed significantly less leakage than unsealed (P < 0.001). Of the sealed groups, amalgam showed less leakage than flowable compomer (P = 0.027). Of the unsealed groups, flowable compomer showed less leakage than both composite groups (P = 0.032 and P = 0.045). Radiographically, the two compomer groups and the amalgam group had fewer adaptation voids than both composite groups (P < 0.001).