Limited evidence for low-level laser in periodontal treatment

Studies in animals and in vitro have suggested that low-level laser therapy (LLLT) suppresses inflammation in periodontal tissue. However, results from clinical studies have given mixed results.

The aim of this review was to assess whether LLLT in combination with conventional mechanical debridement, provides any additional benefits over scaling and root planing (SRP) alone

Methods

Searches were conducted in the PubMed, Embase and Cochrane Library databases. Randomised controlled trials involving the use of LLLT as an adjunct to non-surgical periodontal treatment in patients with chronic periodontitis were considered. Two reviewers screed studies independently and risk of bias was assessed using the Cochrane Risk of Bias tool. Meta-analysis was conducted using a fixed-effects model.

Results

7 RCTs involving a total of 180 patients were included.
3 studies were of parallel arm design a 4 of split mouth design.
6 of the studies were considered to be at high risk of bias and 1 at medium risk
Meta-analysis showed that LLLT-mediated SRP demonstrated significant short-term benefits over SRP monotherapy at 1 month with
Improvement of the probing pocket depth; Mean difference = -0.40; (95%CI; -0.64 to -0.17; p = 0.0009)
Level of interleukin-1β in the gingival crevicular fluid, Standard mean difference= -0.77 (95% CI; -1.35 to -0.18; p = 0.01)
LLLT failed to show significant additional intermediate-term (3 and 6 mo) effects in terms of clinical parameters and alveolar bone density.

Conclusions

The authors concluded

Although LLLT is widely recommended for its biostimulatory and anti-inflammatory roles, it only showed additional short-term merits in reducing the pocket depth after conventional SRP. However, its intermediate-term effects were found to be non-significant. Its long-term adjunctive benefits remain unclear because of the substantial methodological weaknesses and the insufficient number of existing studies. Future RCTs with better study designs, adequate sample power and longer durations of follow-up are required to assess the effectiveness of LLLT as an adjunctive treatment strategy in patients with periodontal disease.

Comments

The reviewers have carried out a broad search of 3 major databases but have only been able to identify 7 small RCTs to address their question. The quality of the included studies is an issue and the authors include a good discussion of the main methodological issues with them and present recommendation for future research, including clarity over inclusion criteria and their clear reporting, sample size calculations, clear reporting of laser parameters and longer follow up periods.