Heat generated within tooth furing clinical denstistry can cause thermally induced damage to hard and soft components of the tooth. Heat transfer in a tooth can be affected by factors such as the geometry of tooth components, thickness of enamel and dentin, type of restoration materials and pulp circulation. Geometrical characteristics of immature tooth are different from those of mature tooth so the purpose of this in vitro study was to investigate thermal changes in immature permanent tooth by using LED light curing unit. Materials and methods: This in vitro study was performed on the second mandibular premolars. Experimental investigation and two dimensional modeling of heat transfer phenomenon in immature and mature teeth were carried out. Sensitivity analysis and local tests were included in the model validation phase. Using LED light curing unit on immature tooth increased the surface temperature up to 48 oC and did not have any harmful effect on th epulp and cement enamel junction temperatures. Sensitivity analysis shows variations in the densities of enamel and dentin did not an effect on the temperature in immature teeth but variations in the heat conductivity of enamel and dentin can affect heat transfer in immature tooth. By use of sensitivity analysis and local testing model validation increased. Using LED light curing unit in immature teeth had no harmful effect on pulp temperature in this study. Sensitivity analysis shows variations in the heat conductivity of enamel and dentin can affect heat transfer in immature tooth; therefore further studies are required to determine thermal conductivity of immature tooth.

Keywords