Background This meta-analysis aimed to compare the efficacy of antimicrobial photodynamic therapy (aPDT) with systemic doxycycline, as adjunctive treatments to scaling and root planing (SRP) for treating periodontitis in patients with type 2 diabetes mellitus (T2DM).

Methods A search across electronic databases including PubMed, Scopus, CENTRAL, OVID EMBASE and OVID MEDLINE was carried out to identify relevant randomised controlled trials (RCTs), comparing aPDT or doxycycline combined with SRP, versus SRP alone. Data were pooled using random-effects models and indirect comparisons were retrieved using the Chi2 test for subgroup differences, to assess the impact of these treatments on glycated haemoglobin (HbA1c), probing depth (PD), and clinical attachment level (CAL).

Results Eight RCTs were included. aPDT with SRP showed a significant reduction in probing depth compared to doxycycline (MD = -0.55 mm, 95% CI: -1.03 to -0.07; p = 0.02). A significant difference between the two subgroups was found (p = 0.04), suggesting aPDT was more effective. No significant differences were found for HbA1c or CAL between the two interventions.

Conclusions The findings suggest that aPDT may offer greater benefits for the treatment of periodontitis in T2DM patients. This suggests that aPDT could potentially be a non-antibiotic alternative to doxycycline. However, as neither treatment influenced HbA1c, clinicians should not rely on periodontal therapy for glycaemic control.

Layperson summary People with type 2 diabetes have a higher risk of getting gum disease because their bodies can’t manage blood sugar levels well. When people with type 2 diabetes get gum disease, the swelling in their gums makes it even harder to control their blood sugar levels, making their diabetes worse. Type 2 diabetics sometimes don’t respond well to regular gum treatments so dentists will also give them antibiotics to treat the gum disease. But when antibiotics are used too often, they can stop working. This is called antibiotic resistance and it’s a big problem in healthcare. Therefore, this study wanted to test if adding a special light therapy to regular gum treatments could replace using antibiotics. The results from this study found that the light therapy was better at healing parts of the gums compared to antibiotics. However, neither treatment made a big difference in blood sugar levels. This is important because it means that the light therapy could replace antibiotics for treating gum disease, reducing the problem of antibiotic resistance. However, more research is needed to see if these treatments could have any beneficial effect on blood sugar levels.

The authors have declared no competing interest.

This study did not receive any funding

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The source data were widely available before carrying out the study.

The data used in the meta analysis were extracted from eight RCTs available on various electronic databases including PubMed Scopus CENTRAL Embase and MEDLINE.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes