Clinical effectiveness of adjunctive diode laser on scaling and root planing in the treatment of periodontitis: is there an optimal combination of usage mode and application regimen? A systematic review and meta-analysis.

This review aims to evaluate the adjunctive clinical effectiveness of diode laser (DL) to scaling and root planing (SRP) in the treatment of periodontitis, and identify the optimal combination of usage mode and application regimen of DL. Eight electronic databases were searched up to January 2021. Probing pocket depth (PPD), clinical attachment loss (CAL), bleeding on probing (BOP), plaque index (PI), and gingival index (GI) were assessed at short-term (4-6 weeks), 3-month, and 6-month follow-ups. Based on DL usage mode, studies were divided into three groups: inside, outside pocket, and combined modes. As for application regimen, studies in each group were further subdivided into single- and multiple-session subgroups. Thirty randomized controlled trials with 825 participants were included. For inside mode, single-session DL showed significant improvements for PPD (short-term, and 3-month, p < 0.05), CAL (short-term, and 3-month, p < 0.05), PI (3- and 6-month, p < 0.05), and GI (short-term, 3-month, and 6-month, p < 0.05). For outside mode, multiple-session DL showed notable improvements for most clinical outcomes (p < 0.05). The effect of combined mode was still uncertain. Adjunctive DL had additional clinical benefits in the treatment of periodontitis. One session laser treatment is suggested when DL is applied inside pocket in future clinical practice. Meanwhile, more than one session laser treatment presents better outcomes when DL is used outside pocket. PROSPERO: CRD42020156162.