Effect of different placement methods on voids formationin class ii cavity restored with bulk-fill resin composite

Abstract

The aim of this study was to evaluate void formation by micro-computed tomography in two-surface Class II cavities restored with two bulk-fill resin composites using different placement methods. Standardized Class II cavities were prepared in forty intact human maxillary first premolar teeth. The teeth were randomly divided into four groups and restored with (n=10): 1) one bulk placement with hand instrument; 2) two-bulk placement with hand instrument; 3) one bulk placement with injectable dispenser; 4) one bulk placement with injectable dispenser and sonic-activated handpiece. Percentage of void formation in the entire restoration was evaluated. Welch's ANOVA and Games-Howell post hoc analyses were performed with a significance level of 0.05. One bulk placement with hand instrument (group 1) and two-bulk placement with hand instrument (group 2) had significantly higher percentage of void formation than one bulk placement with injectable dispenser (group 3) and one bulk placement with injectable dispenser and sonic-activated handpiece (group 4). There was no significant difference in percentage of void formation between the hand instrument placement groups (group 1 and group 2) and also between the injectable dispenser groups (group 3 and group 4). In conclusion, different placement methods affected void formation in two-surface Class II cavity restored with bulk-fill resin composite. Placement with hand instrument had significantly higher void formation than placement with injectable dispenser.