Sepideh Soheilifar
Sara Soheilifar
Shayesteh Hatami
Farshid Vahdatinia
Vahid Molabashi
Mehrdad Hajiloui
Pouria Teymouri

Background: In recent years, there has been an increased tendency for using dental lasers for the treatment of soft tissue problems. The aim of this study was to evaluate the effect of low-level diode laser (۹۸۰ nm) on the level of interleukin ۱ beta (IL-۱β) in the gingival crevicular fluid (GCF) and the incidence of initial gingivitis caused by the use of orthodontic separators. Methods: In this randomized clinical trial, ۳۰ patients, who were beginning a fixed orthodontic treatment without gingivitis, were randomly assigned to control and diode laser radiation (۹۸۰ nm wavelength, ۳ J of energy, a density of ۳ J/cm۲ , a power of ۰.۲ W, and at a distance of ۱ cm away from the tissue for ۱۵ seconds on the buccal and palatal sides of the tooth) groups. The gingival index (GI) and bleeding on probing (BOP) were measured at the beginning of the study and one week after the treatment. The level of IL-۱β was evaluated using an enzyme-linked immunosorbent assay at the beginning of the study and one week after the placement of the separator. Finally, the inter-group and intra-group statistical analyses were performed using independent and paired t tests, and P<۰.۰۵ was considered as the significance level. Results: The evaluation of clinical variables in the entire mouth showed a slight clinical improvement in the experimental group although there was no significant difference between the two groups. No significant difference was observed between intra-group and inter-group evaluations of clinical indices in the studied specific teeth. Eventually, no difference was found between the two groups in terms of IL-۱β changes. Conclusions: In general, the single-diode laser radiation session is not effective in the treatment of gingivitis in patients undergoing orthodontic treatment. Thus, it is recommended to perform frequent laser radiation sessions in further studies.