Bleaching effect on pulpless tooth with simultaneous use of Nd:YAG laser

The purpose of this study is to report some knowledge gained from experiments in which we tried tooth bleaching using laser and bleaching agents on pulpless tooth due to trauma. We conducted in vitro experiments using extracted teeth of lower permanent central incisors with the following four conditions: (1) using 30% hydrogen peroxide (H2O2) and Nd:YAG laser, without Indian ink; (2) in addition to the condition of (1), with Indian ink; (3) using laser in conjunction with H2O2 and sodium perborate, without Indian ink; (4) in addition to the conditions of (3), with Indian ink. The bleaching agents that used 30% H2O2 and sodium perborate had more bleaching effects than the one with 30% H2O2 only. Furthermore, translucency was not lost in the cases in which Indian ink was not used. Obtaining above results, we conducted clinical trials under condition (3). In three trial cases, changes in shade were observed after the bleaching treatment. Largely satisfactory results were gained with over three times radiation in two clinical cases. After the bleaching treatment, the patients had no perceptive or apparent symptoms. Little recurrence of discoloration was found. [Copyright &y& Elsevier]