Various ways of pre-heating a bulk-fill thermoviscous composite in restoration in non-carious cervical lesions: 12-month randomized clinical trial

Objective The objective of the study is to evaluate through a randomized clinical trial the best method to preheat a composite resin, if using a Caps dispenser device associated with Caps Warmer (CD) or with a VisCalor Caps dispenser/warmer (VD) for restorations in non-carious cervical lesions (NCCLs). Material and Methods One hundred and twenty restorations were distributed to two groups ( n = 60) according to the pre-heating way of thermoviscous bulk-fill composite resin. For the CD group, pre-heating was carried at 68 °C using a heating bench for 3 min. For the VD group, pre-heating was performed at 68 °C using a heating gun for 30 s. After that, pre-heated bulk-fill composites were directly inserted in the NCCLs. The total working time was recorded. The restorations were evaluated after 6 and 12 months of clinical performance according to the FDI criteria. Statistical analysis was performed using the Student’s t test for unpaired samples for working time, and the Chi-square test for restoration clinical performance ( α = 0.05). Results Working time was shorter for VD with a statistically significant difference compared to CD ( p = 0.01). Few restorations were lost or fractured after 12 months of clinical evaluation ( p > 0.05). The retention rates were 96.7% (CI 95 %: 88.6–99.1%) for CD and 98.3% (CI 95 %: 91.1–99.7%) for VD. The other FDI parameters were considered clinically acceptable. Conclusions The different pre-heating ways did not influence the clinical performance of thermoviscous bulk-fill composite restorations in NCCLs after 12 months. Clinical relevance Regardless of the bulk-fill thermoviscous composite resin pre-heating ways, the restorations are clinically acceptable after 12 months.