Comparative Assessment of Cuspal Deflection in Premolars Restored With Bulkfill and Conventional Composite Resins

Objectives: it has been reported that bulkfill composites simplify tooth restoration with no adverse effect on the success rate. this study sought to assess the cuspal deflection of premolars with mesioocclusodistal (mod) cavities restored with bulkfill and conventional posterior composite resins.materials and methods: this invitro experimental study was conducted on 64 human maxillary premolars. mod cavities were prepared on teeth and restored with filtek p60 conventional composite and filtek bulk fill flowable, xtra fill, and xtra base bulkfill composites in four groups (n=16). distance between the cusp tips was measured before, five minutes, 24 hours, 48 hours, and one week after restoration. the data were analyzed using repeatedmeasures analysis of variance (anova) and tukey’s test (α=0.05).results: the mean±standard deviation (sd) of cuspal deflection at five minutes after the restoration was 13.5±5.3, 12.2±3.5, 11.3±4.4, and 10.4±3.7 µm for filtek p60, filtek bulk fill, xtra fill, and xtra base, respectively. anova showed that bulkfill composites did not cause a significant reduction in cuspal deflection compared to p60 (p>0.05). cuspal deflection in all groups significantly decreased with time (p<0.05).conclusion: bulkfill composites have no superiority over p60 in the reduction of cuspal deflection. the cuspal deflection was variable at different time points in all groups and decreased over time.