Various studies have recommended parameters for the use of Er:YAG laser for the treatment of caries of the enamel and dentin without studying the increase in temperature caused by laser in the individual groups of teeth. The Er:YAG laser has been indicated for the removal of caries, cavity preparation and preparation and disinfection of root canals. The authors studied the intrapulpar temperature change in 10 incisors, 10 canines, 10 pre-molars and 10 molars during Class V cavity preparation with focused short pulse and very short pulse Er:YAG laser, using the following parameters: 10 Hz frequency, 500 mJ per pulse, 6 s, 10 mm distance, 25 ml/min water flow, at 23 degrees C and 65 percent humidity. The greatest increase in temperature was found in the incisors and the least increase in the molars at both pulse modes. The very short pulse mode caused less of an increase in temperature in the pulp chamber in all teeth than the short pulse mode.