In Vivo Temperature Measurement: Tooth Preparation and Restoration with Preheated Resin Composite

Abstract

Composite preheating has shown to improve material physical properties in vitro, but no data exist on the use of this technique in vivo during placement. The study aims to measure in vivo prepared tooth surface temperature during a restorative procedure using resin composite either at room temperature (23.6°C) or preheated to 54.7°C in a commercial compule heating device set to heat at 60°C. Class I preparations (N=3) were made on a patient requiring multiple posterior restorations. A probe containing two thermocouples was used to record temperature values at the tooth pulpal floor and 2mm higher (top of the tooth preparation/restoration) after tooth preparation (prep), acid etching (etch), placement and curing of a bonding agent (BA), and during placement of composite used at room temperature (RT) or preheated in a commercial device (Calset(TM) , AdDent Inc., Danbury, CT, USA) set to 60°C. Data were compared with two-way analysis of variance, Tukey-Kramer post hoc test (α=0.05). No significant difference in pulpal floor temperature existed between prep (27.8°±1.3°C) and etch (26.3°±1.3°C), which were significantly lower than BA (30.5°±1.3°C) (p=0.0001). Immediate placement of preheated composite resulted in significantly higher pulpal floor (36.2°±1.9°C) (p=0.0025) and top composite temperatures (38.4°±2.2°C) (p=0.0034) than RT values (30.4°±2.2°C and 29.6°±0.9°C, respectively). In vivo use and placement of preheated resin composite resulted in temperature increase of 6° to 8°C than room temperature material. These values, however, were much lower than expected. Although having many potential benefits, composite preheating may not be as clinically effective in delivering resin of predetermined temperature at the time of cure as laboratory experiments would suggest. Despite only moderate composite temperature increase over use of room temperature material, preheating still provides advantages in terms of ease of handling and placement.