The effect of bleaching gel and (940nm and 980nm) diode lasers photoactivation on intrapulpal temperature and teeth whitening efficiency

摘要

This invitro study aimed to investigate the whitening efficacy of 940nm and 980nm diode laser photoactivation in tooth bleaching by analysing pulp chamber temperature, as well as the change in tooth colour. Root canals of thirty extracted human lower premolars were prepared. Laserwhite* 20 bleaching agent containing 38% of hydrogen peroxide was photoactivated with 7W output power of 940nm and 980nm diode lasers for 120 s. Bleaching gel reduced 27-29% of the temperature from reaching the pulp chamber. For shade assessment, only the groups photoactivated using diode lasers showed statistically significant differences from control group P<0.001. Within the studied parameters, both 940nm and 980nm diode lasers produced a safe pulp temperature increase. Diode laser photoactivation of bleaching gel resulted in more efficient teeth whitening. Photoactivation with 940nm diode laser yielded the highest change in colour with only minor increase in pulp chamber temperature.