The Adjunctive Role of Antimicrobial Photodynamic Therapy to Non-Surgical Treatment in Patients with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis

Abstract

Background: This systematic review aimed to assess the outcomes related to the use of antimicrobial photodynamic therapy (aPDT) as an adjunct to non-surgical periodontal treatment (NSPT) of patients affected by periodontitis and with type 2 diabetes mellitus (T2DM). Methods: PubMed, Cochrane Library, Scopus, and Web of Science (core collection) were queried up to January 2025. The PICO question investigated the comparison between T2DM patients undergoing NSPT with or without aPDT, in terms of improvement of clinical parameters. Two independent operators performed the study selection, data extraction, and risk of bias assessment (RoB-2 tool). The meta-analysis examined the reduction in bleeding on probing (BoP) and probing pocket depth (PPD) in sites > 4 mm, reporting mean difference (MD) and 95% confidence intervals (CIs). Results: Among 502 studies retrieved, 15 were finally included in the systematic review and meta-analysis. In T2DM individuals, the adjunct of aPDT to NSPT demonstrated a substantial reduction in BoP and PPD after 3 and 6 months compared to the use of NSPT alone. Conclusions: The outcomes of this systematic review suggest that adjunctive aPDT may provide additional benefit to NSPT in reducing inflammation in T2DM patients with periodontitis, indicating that this combined therapy could represent a potentially useful approach for individuals with T2DM. Review registration: registration in PROSPERO (International prospective register of systematic reviews) with ID CRD42024506295 on 6 February 2024.

Keywords: adjunctive therapy; antimicrobial photodynamic therapy; diabetes mellitus; periodontitis.

Figure 1

PRISMA flow diagram of the search and selection process [35].

Figure 2

Risk of bias in the included studies.

Figure 3

Forest plot of PPD at 3-month follow-up in aPDT + NSPT test group and NSPT control group, according to study-design sub-group analysis.

Figure 4

Forest plot of PPD at 6-month follow-up in aPDT + NSPT test group and NSPT control group, according to study-design sub-group analysis.

Figure 5

Forest plot of BoP at 3-month follow-up in aPDT + NSPT test group and NSPT control group. Study design was RCT with patients’ assignment for all studies, so sub-group analysis was not included.

Figure 6

Forest plot of CAL at 3-month follow-up in aPDT + NSPT test group and NSPT control group, according to study-design sub-group analysis.

Figure 7

Summary of findings: * The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI); CI: confidence interval; MD: mean difference. GRADE Working Group grades of evidence: High certainty (we are very confident that the true effect lies close to that of the estimate of the effect); Moderate certainty (we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different); Low certainty (our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect); Very low certainty (we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of the effect). ^a: Visual inconsistency and statistical analysis also showing heterogeneity; ^b: The evidence directly answers the health care question.