Does laser treatment restore the bond strength of resin composites to recently bleached enamel? A systematic review and meta-analysis

PURPOSE To do a systematic review and meta-analysis to determine whether laser treatment affects the bond strength of resin composites to recently bleached enamel. METHODS This report follows the Preferred Reporting Items for Systematic Reviews and Qualitative Analyses (PRISMA) statement. Medline via PubMed, Embase, Web of Science, and the Cochrane Library databases were searched with no limits on publication year. Two reviewers independently screened all titles and abstracts to perform the study selection, data extraction, and risk-of-bias assessments. A random-effects meta-analysis model was performed using Review Manager software (version 5.3, Cochrane Collaboration). RESULTS From the 93 records identified, seven articles that met all the inclusion criteria were included in the systematic review, and six studies were included in the meta-analysis. The overall results showed a statistically significant difference in bond strength between the control group and laser-treated group (P= 0.04; mean difference: 5.27; 95% confidence interval: 0.28 to 10.27), favoring the laser-treated group. Subgroup analyses revealed that the tooth source (bovine or human teeth) contributed to the effect of laser treatment on the bleached enamel. CLINICAL SIGNIFICANCE Laser treatment may increase the bond strength of resin composites to recently bleached enamel. Pretreatment with a laser, preferably with Nd:YAG (1 W, frequency of 10 Hz, irradiation time of 60 seconds) or CO2 lasers (0.5 W, frequency of 10 Hz, irradiation time of 60 seconds), may be recommended to restore the bond strength of recently bleached enamel