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Statement of the Problem: Several techniques are proposed for the restoration of Class V cavities but there is no agreement in the literature as to which technique is more effective., Purpose: To evaluate the effect of different techniques of composite increment placement on the marginal adaptation of Class V restorations., Methods and Materials: Twenty-four human molars were selected and prepared with standardized saucer-shaped cavity dimensions of 3.0 mm (occlusal-gingival), 2.0 mm (mesial-distal), and 2.0 mm (depth). The margins are in reference to the cemento-enamel junction with 1.5 mm being located on enamel and 1.5 mm on dentin. The cavities were randomly assigned into three groups (n=8) and restored with composites as follows: Group 1, the occlusal increment was placed and cured first followed by the gingival increment; Group 2, the gingival increment was placed and cured first followed by the occlusal increment; and Group 3, the cavities were restored with one bulk increment. Restorations were immediately finished and stored for 24 h in tap water. Specimens were subjected to thermocycling (1000 cycles, 5 degrees C to 55 degrees C, 30 s dwell time) and immersed in 0.5% basic fuchsin solution for 24 h in room temperature. After rinsing with running water, the restorations were sectioned longitudinally and enamel and dentin margins were evaluated and scored according to the microleakage on a 0-3 scale. Data were subjected to Kruskal-Wallis test at p<0.05., Results: Median of microleakage scores for all evaluated groups was zero. No statistical difference was observed among the three groups both in enamel (p = 0.5929) and dentin (p = 0.3679) margins, Conclusion: The placement technique did not influence the marginal adaptation of moderate Class V restorations., Clinical Significance: No differences on marginal adaptation were observed when restoring conservative Class V cavities using incremental or bulk placement techniques.

Objective: The purpose of this in vitro study was to investigate the microleakage at dentin margins of a flowable resin composite associated with an adhesive, either light cured separately or co-cured, in Class V cavities., Materials and Methods: Twenty four recently extracted human molars were prepared with standardized box-shaped Class V cavities of 3.0 mm (mesial-distal), 2.0 mm (occlusal-gingival), and 2.0 mm depth with margins located on enamel and dentin/cementum on the buccal or lingual surfaces. The cavities were randomly assigned into three groups (n=8): Group I - Single Bond + Filtek Z250 (control); Group II - Single Bond + Filtek Flow (light cured separately) + Filtek Z250; and Group III - Single Bond + Filtek Flow co-cured (light cured simultaneously) + Filtek Z250. After being immersed in tap water for 24 h, the specimens were thermocycled (1000x, 5 degrees -55 degrees C, 30 sec dwell time) and immersed in a 0.5% basic fuchsine solution for 24 h. The restorations were sectioned longitudinally and gingival margins were evaluated for microleakage using a 0-4 scale. Data were subjected to the Kruskal-Wallis test at p<0.05., Results: A statistically significant difference at p = 0.0044 between Groups 1 and 3 and Groups 2 and 3 was observed. Although Group 2 performed slightly better than Group 1, no significant difference was observed., Conclusion: The use of a flowable resin composite cured simultaneously with an adhesive yielded the worst results in this study. As no statistical differences were seen between Groups 1 and 2, the use of a flowable composite as a means of minimizing microleakage at dentin margins may be questioned.