Dentinal temperature rise during photo-activation of restorative composites.

Aim The rise of temperature during polymerization might affect tooth pulp with potential pulpar damage. This study aims to investigate dentinal temperature increase during light activation of bulk fill materials using different restoration techniques.

Materials and methods Extracted premolars received standardized MOD preparations. K-type single-use thermocouples were used to measure temperature profiles. Thermocouples were placed in a standardized hole created within each premolar 1 mm below the cavity floor. Each specimen was heated at 35°C through the ThermBlock system (FALC), and this temperature was kept constant during the test. The EMS Swiss Master Light lamp 1000 mW/cm² operating for 20 s was used for the polymerization process. Data were subjected to statistical analysis (one-way anova).

Results Flowable composites show higher temperature rise(p<0.05) than packable composites. Peak temperatures higher than 42°C were measured for the incremental layering technique using flowable composites.

Conclusions Use of bulk-fill technique shows safe temperature values in association with light curing modality of 1000 mW/cm2 for 20 s. Otherwise, for the incremental layering technique, potentially dangerous temperature peaks have been measured for flowable composites.