One-year clinical evaluation of bulk-fill composite resin restorations plasticized by preheating and ultrasonics: A randomized clinical trial.

Introduction: Bulk-fill composite restorations displayed substantial annual failure related to imperfect marginal adaptation. Although preheated composites improved, marginal adaptation demonstrated early loss of plasticity. A new technique of ultrasonics plasticization was used for fabricating restorations.

Aim: The aim of this study was to assess the clinical behavior of bulk-fill composite resin restorations plasticized by preheating and ultrasonics.

Methodology: Randomized split-mouth double-blinded clinical trial was designed. Bulk-fill composite resin (Tetric N-Ceram Bulk Fill Ivoclar Vivadent products, Delhi) was used to fill 56 cavities. In 28 restorations, composite resin was plasticized by preheating in composite warmer (Delta Co., India) and remaining were plasticized with modified ultrasonic-retreatment tip-RT No 2 (Cricdental, India). Clinical follow-up assessments were done at 6 and 12 months using Ryge's criteria. Mann-Whitney -test was used for statistical analysis with < 0.05 and effect size of 0.61.

Results: Hundred percent clinical success with ultrasonic plasticized group and 95.2% success with preheated composite resin group were observed without statistical significance.

Conclusion: The ultrasonics plasticization of composite resin demonstrated comparable results with that of preheated composite resin after 6- and 12-month recall. Use of vibration energy utilizing the thixotropic effect might have resulted in better clinical performance.