Assessment of preparation time and 1-year Invisalign aligner attachment survival using flowable and packable composites: A split-mouth clinical study

Objectives: To compare preparation time and 1-year Invisalign aligner attachment survival between a flowable composite (FC) and a packable composite (PC). Materials and Methods: Fifty-five participants (13 men and 42 women, mean age 6 SD: 24.2 6 5.9 years) were included in the study. Ipsilateral quadrants (ie, maxillary and mandibular right, or vice versa) of attachments were randomly assigned to the FC group (Filtek Z350XT Flowable Restorative) and the PC group (Filtek Z350XT Universal Restorative) by tossing a coin. The primary outcome was preparation time. The secondary outcome was time to the first damage of an attachment. Preparation times were compared using the paired t-test, and the survival data were analyzed by the Cox proportional hazards model with a shared frailty term, with alpha = .05. Results: The preparation times were significantly shorter with the FC (6.22 +/- 0.22 seconds per attachment) than with the PC (32.83 +/- 2.16 seconds per attachment; P,.001). The attachment damage rates were 14.79% for the FC and 9.70% for the PC. According to the Cox models, attachment damage was not significantly affected by the attachment material, sex, arch, tooth location, attachment type, presence of overbite, or occurrence of tooth extraction. Conclusions: The use of a FC may save time as compared with the use of a PC. With regard to attachment survival, there was no significant difference between the two composites. None of the covariates of attachment materials (sex, arch, tooth location, attachment type, presence of overbite, oir occurrence of tooth extraction) affected attachment damage.