Influence of low-level laser therapy on orthodontically-induced inflammatory root resorption. A systematic review

Objective: The aim was to assess the influence of low-level laser therapy (LLLT) on orthodontically-induced inflammatory root resorption (OIIRR). Methods: A systematic search was conducted in indexed databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The eligibility criteria were as follows: (a) original clinical and animal/experimental studies; (b) prospective studies; (c) intervention: effect of LLLT on OIIRR; (d) control group (OIIRR without LLLT); (e) statistical analysis; and (f) tomographic or histologic assessment of OIIRR. Quality assessment of the experimental and clinical studies was performed following the Animal Research Reporting In-vivo Experiments (ARRIVE) and Consolidated Standards of Reporting Trials (CONSORT) guidelines, respectively. The risk of bias of the included studies was also determined. Results: Nine (7 experimental and 2 clinical) of the initially identified 39 studies were included. One clinical and 2 experimental studies showed that LLLT during orthodontic tooth movement (OTM) significantly reduces OIIRR. One experimental study reported that LLLT during OTM in sockets treated with alloplastic materials significantly reduces OIIRR. One experimental study found that LLLT after OTM significantly repairs OIIRR, whereas one clinical study did not report a significant reparative affect. Three experimental studies showed that LLLT increases OIIRR during OTM, corticotomized-OTM, and OTM into grafted defects, respectively. The minimum, median and highest ARRIVE scores (out of 20) of the included experimental studies were 15, 17 and 19, respectively. The mean CONSORT score of the included clinical studies was 23 (out of 25). Conclusions: In conclusion, the influence of LLLT on OIIRR remains debatable.