Model of thermal and optical effects in dental pulp during the neodymium and diode lasers irradiation

Applications of high intensity lasers in the enamel and dentine can produce adverse thermal effects into the pulp. Since the evaluation thermal effects into the intact pulp is not a solved problem, extracted teeth models have been used frequently. Current models, however, simulate only tooth thermal properties, not taking the remaining radiation in the pulp chamber into account. The aim of this study was to verify if the remaining radiation from neodymium and diode lasers that reach the pulp chamber, at the models using extracted bovine teeth, can causes local thermal effects. For this purpose, two models were developed using extracted bovine teeth with their pulp chambers filled with: water (model 1) and with an optical absorbent (model 2). Models were radiated with 1 W. The obtained results show that, for both lasers, the temperature rise in model 2 pulp chamber is: i) up to 11% higher than in the model 1 when the enamel is radiated and ii) up to 37% higher than in the model 1 when dentine is radiated (1 mm from the pulp). Thus, remaining radiation into the pulp is relevant for the above mentioned lasers and doses.