Efficacy of sodium perborate assisted by Er:Cr;YSGG laser induced photoacoustic streaming technique for enhancing the color of internally stained teeth

To investigate the efficiency of sodium perborate (SP)-20% H2O2 bleachingagent with and without Er:Cr;YSGG laser induced photoacoustic streaming technique (PIPS).

Forty-two sound premolars were used. The teeth were endodontic ally treated, artificial staining is achieved by using sheep’s blood and arbitrarily subclassified into two groups. Group 1 was bleached by SP-20% H2O2 assisted by Er:Cr;YSGG laser (25 Hz frequency, W power, 60 µs pulse duration) and Group 2 was treated conventionally (i.e. walking bleaching with SP-20% H2O2). The results were evaluated after 1, 2 and 3 weeks and the resulting colour changes were measured using a digital spectrophotometer. Statistically, both intragroup and intergroups were compared using ANOVA and unpaired t-test respectively .

An intergroup comparison between the bleaching outcomes of each method demonstrated that Er:Cr;YSGG laser with SP-20% H2O2 (Group 1) was significantly (p < 0.05) more effective than walking bleaching using SP-20% H2O2 (Group 2) for all evaluated time intervals.

Using of PIPS technique to activate the bleaching substance which contains SP 20% H2O2 was more efficient in achieving desirable bleaching outcomes than the conventional walking bleaching technique.