ABSTRACT Objective The study answers the PECO question: “In adults with dental implants
(P), do subjects suffering from type-2 diabetes or prediabetes (E) have worse peri-implant
conditions (O) than subjects without type-2 diabetes and prediabetes (C)?”. Prediabetes
(5.7-6.4% HbA1c), and the different qualities of glycemic control in type-2 diabetes;
well-controlled (>8% HbA1c), and poorly controlled (>8% HbA1c) individuals; were classified
according to the recommendations of the American Diabetes Association. Data Predefined
search keys were used with search terms including: Dental implant, diabetes mellitus,
glycemic control and HbA1c. Sources An electronic search in the MEDLINE, Embase, and
Cochrane libraries were conducted without any filters or language restrictions. Additionally,
manual search of the reference lists were carried out to identify all relevant articles.
Study Selection Eligibility criteria were cohort, case-control and cross-sectional
studies that answerd our PECO question with at least 1 year of follow-up. From a total
of 2660 records, 35 articles (1761 individuals) were included in the analysis. Meta-analytic
difference in means for crestal bone loss was 1.2 mm [95% CI=0.4; 2.1] in patients
with prediabetes, 1.8 mm [CI=1.0; 2.7] in poorly controlled patients, whereas 0.4
mm [CI=-0.3; 1.1] in well-controlled individuals. Meta-regression showed that 1% increase
in HbA1c increased crestal bone loss by 0.24 mm. Conclusions Within the limitations
of the study, patients with poorly controlled type-2 diabetes or prediabetes may have
worse peri-implant conditions compared to patients without diabetes and well-controlled
type-2 diabetes. Well-controlled type-2 diabetes is not a risk indicator for peri-implant
diseases. Clinical Significance Clinicians should measure blood HbA1c levels when
planning implant-supported restorations, thus patients with undiagnosed or poorly
controlled type-2 diabetes can be identified, that allows for glycemic level adjustment
by the diabetologist specialist prior to dental implant surgery, ensuring peri-implant
health. Protocol registration number (CRD42022375263)
