Meta-regression Analysis of Study Heterogeneity for Systemic Outcomes after Periodontal Therapy

Current scientific evidence for why periodontitis should be included in diabetes management

This Perspective provides a brief summary of the scientific evidence for the two-way links between periodontal diseases and hyperglycemia (diabetes mellitus [DM] and pre-DM). It delivers in a nutshell current scientific evidence for manifestations of hyperglycemia on periodontal health status and effects of periodontal diseases on blood glucose levels and in turn incidence, progression, and complications of diabetes. Of outmost importance is presentation of scientific evidence for the potential of routine periodontal treatment to lower blood glucose levels, providing a novel, economical tool in DM management. Non-surgical periodontal treatment ("deep cleaning") can be provided by dental hygienists or dentists in general dental offices, although severe cases should be referred to specialists. Such therapy can decrease the costs of DM care and other health care costs for people with DM. The great importance of a healthy oral cavity free of infection and subsequent inflammation - especially periodontitis that if untreated will cause loosening and eventually loss of affected teeth - has largely gone unnoticed by the medical community as the health care curricula are largely void of content regarding the bi-directional links between oral health and systemic health, despite elevation of blood glucose levels being an integral part of the general systemic inflammation response. The importance of keeping disease-free, natural teeth for proper biting and chewing, smiling, self-esteem, and pain avoidance cannot be overestimated. Medical and dental professionals are strongly encouraged to collaborate in patient-centered care for their mutual patients with - or at risk for - hyperglycemia.

Effect of subgingival periodontal therapy on glycaemic control in type 2 diabetes patients: Meta-analysis and meta-regression of 6-month follow-up randomized clinical trials

BACKGROUND

Periodontitis worsens the hyperglycaemia in patients with type 2 diabetes mellitus (T2DM). Subgingival instrumentation, with or without surgical access, is the gold-standard treatment for periodontitis. The aim was to summarize the evidence on the effect of subgingival instrumentation (with or without open flap) on the reduction of glycosylated haemoglobin (HbA1c).

METHODS

Nine electronic databases were searched up to 15 February 2023. Twelve randomized controlled trials with at least 6 months of follow-up were included. Studies using systemic or local-delivery antimicrobial therapies were excluded. Meta-analyses were performed using the random-effects model. The sources of heterogeneity were assessed by applying linear meta-regression. Risk of bias was assessed by RoB 2, and certainty of evidence by GRADE.

RESULTS

Eleven studies were included in the quantitative analyses (1374 patients). Subgingival instrumentation resulted in 0.29% lower HbA1c (95% confidence interval: 0.10-0.47; p = .03) compared with non-active treatment.

DISCUSSION

None of the 12 studies were assessed as having low risk of bias. The percentage of females and the time of diabetes diagnosis significantly explained the high level of heterogeneity. Subgingival periodontal therapy results in a significant and clinically relevant improvement in glycaemic control over 6 months in patients with T2DM and periodontitis. The grade of evidence was moderate.