In this paper, a new 12-node triangular element is developed for the analysis of composite plates. Moreover, the stress-strain relations of laminated bending plates, along with the characteristics of composite and piezoelectric materials have also been investigated. Following this, a finite element formulation for smart composite bending plates is proposed. The capability of the suggested element in analyzing both composite plates and smart ones is studied via numerical examples. These analyses demonstrate that the proposed element is capable of yielding accurate results for the given problems. In addition, it is also concluded that in comparison to the elements developed by other researchers, this new formulation leads to more precise outcomes.

Objectives: It has been reported that bulk-fill composites simplify tooth restoration with no adverse effect on the success rate. This study sought to assess the cuspal deflection of premolars with mesio-occluso-distal (MOD) cavities restored with bulk-fill and conventional posterior composite resins. Materials and Methods: This in-vitro 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, X-tra fill, and X-tra base bulk-fill 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 repeated-measures 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, X-tra fill, and X-tra base, respectively. ANOVA showed that bulk-fill 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: Bulk-fill 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.