Materials and methods. This study was performed on the second mandibular premolars. Experimental investigation was carried out for recording temperature variations of different sites of tooth and two dimensional finite element models were used for heat transfer phenomenon in immature teeth. Sensitivity analysis and local tests were included in the model validation phase. 

Results. Overall thermal stimulation for 30 seconds by using a low-intensity LED LCU increased the temperature from 28°C to 38°C (a 10°C increase) in IIT and PIT. When a high-intensity LED LCU was used, tooth temperature increased from 28°C to 48°C (a 20°C increase). The results of the experimental tests and mathematical modeling illustrated that using LED LCU on immature teeth did not have any detrimental effect on the pulp temperature. 

Conclusion. Using LED LCU in immature teeth had no effect on pulp temperature in this study. Sensitivity analysis showed that variations of heat conductivity might affect heat transfer in immature teeth therefore, further studies are required to determine thermal conductivity of immature teeth.