The effect of low level laser therapy (LLLT) on bone remodelling after median diastema closure: A one year and half follow-up study

Abstract

Background and objectives Maintenance of a corrected median diastema after orthodontic treatment often requires permanent retention. This study was performed to evaluate low level laser therapy (LLLT) effect on bone density after diastema closure and to determine whether increased density will prevent diastema relapse. Study design Fourteen patients (22 ± 4.78 years) with median diastema (6.79 ± 2.28 mm) were randomly allocated to a lased and a non-lased group ( i = 7). The patients in the lased group were exposed to GaAs (904 nm, 30 mW, 5.4 J/session, 3 times/3 min each/every second day). Standardized periapical radiographs of the maxillary central incisors were taken immediately after diastema closure, and at 15 days, 45 days, 3 months, 6 months and 1.5 years. Bone density and linear distances were measured using Digora software. Results Diastema reopening showed no statistically significant differences between the two groups. Reduction in linear distances was noticed in the lased group. Mean percentage changes in bone density were statistically significant between the groups at 15 days and 6 months. Only the periapical area distal to the right central incisor retained significantly higher bone density after 1.5 years. There was an insignificant negative correlation between the diastema size and bone density in the lased group at all experimental periods. Conclusions LLL induced bone remodelling and prevented reduction in bone density in the lased group. Diastema reopening, although minor, did not seem to be significantly affected by the bone density changes. Further studies on a larger sample are necessary to optimize treatment parameters so LLL can be applied on a routine therapeutic basis.