LASER-INDUCED THERMAL EVENTS IN EMPTY AND PULP-FILLED DENTAL-PULP CHAMBERS

Background and Objective: The purpose of this investigation was to eva luate: 1. thermal events during laser irradiation @2.1 mu m of the pul p; 2. whether these effects are adequately modeled using an empty pulp chamber/root canal. Study Design/Materials and Methods: In extracted human teeth, pulpal access was prepared and thermocouples placed 2, 3 mm apical to the center of the irradiation spot. Pulp-filled or empty pulp chambers mere irradiated using a Ho:YAG laser: Spot Size: 1 mm; P ower: 1, 2, 3.5, 4.5W; PRR: 5, 12 Hz; Duration: 10 sec, Thermal measur ements were repeated 3x. Results: Thermal trends did not differ signif icantly and correlated positively with power (P < 0.01), PRR (P < 0.01 ), irradiation duration (P < 0.05). No significant difference was dete rmined between temperatures in empty and pulp-filled chambers at all p arameters at 5 Hz and at 1-2W at 12 Hz (P < 0.05, a-tailed Student's t -test). At 12 Hz and >3.5W, pulp chamber temperatures exceeded those i n pulpal tissue (P<0.05). Conclusion: Pulp tissues must be present to ensure clinical relevance of thermal measurements. (C) 1998 Wiley-Liss , Inc.