RESUMO
Animal studies have ascertained that hyperglycemia adversely affects bone metabolism and dental implant osseointegration. However, diabetic patients show low occurrence of unfavorable hard or soft peri-implant tissue changes, differences that are possibly due to treatment with anti-diabetic medications. This scoping review aimed to systematically examine the effects of these drugs on implant outcomes and explore the predictive modality of animal studies for clinical practice according to type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). Three electronic databases (MEDLINE, EBSCOHost, and Cochrane) were searched according to the PRISMA-ScR standards for studies on diabetic animals that received titanium implants and anti-diabetic treatments. Risk assessment was performed using the SYRCLE Risk-of-Bias (RoB) tool. Twenty-one papers were included, encompassing six types of medications. Fifteen studies were on T1DM animals, and only six involved T2DM models. T1DM animals were treated with non-insulin drugs in four investigations, while insulin was utilized in 11 other studies. In T2DM experiments, five administered non-insulin drugs, and only one applied locally delivered insulin. Only insulin in T1DM studies produced a positive influence on bone-implant contact (BIC), bone mineral content, and removal torque values. Inappropriate drug selection, inadequate glycemic control, and high RoB depict a mismatch between the research focus and the translational rationale to clinical practice. There remains a knowledge gap regarding T2DM investigations due to the lack of studies. More data are needed concerning intraoral implants and the performance of osseointegrated implants in patients with a later onset of diabetes. Future research should reflect the pathophysiology and treatment of each type of diabetes to ensure clinical applicability.
RESUMO
OBJECTIVES: To comprehensively evaluate implant survival, clinical and biochemical parameters, as well as possible dose-response relationship with hemoglobin A1c (HbA1c) in patients with differing diabetic control. METHODOLOGY: Five electronic databases were searched for studies that compared implant outcomes in patients with differing HbA1c values. Research quality was evaluated using Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) tool. Narrative synthesis and meta-analysis were performed for survival rate, plaque index (PI), bleeding on probing (BOP), probing pocket depth, and marginal bone loss (MBL). Categorical dose-response meta-analysis (DRMA) was conducted according to length of follow-up. RESULTS: Twenty-two studies met the inclusion criteria. Prospective studies were mostly of moderate quality, but non-prospective papers had serious to critical risk of bias. Survival rate was high for the first 3 years (92.6%-100%) for patients with HbA1c less than 8%. Meta-analysis revealed worsening clinical parameters with increasing HbA1c. DRMA further established a significant dose-response relationship between glycemic control with BOP (10% more bleeding, 95% CI 0.05-0.16, P = .008) and MBL (0.05 mm more bone loss, 95% CI 0.01-0.09, P = .002) per HbA1c category, but no association with probing pocket depth. Osseointegration progressed at a slower rate, and inflammatory cytokines and bone biomarkers were adversely affected in patients with HbA1c above 8%. CONCLUSION: Moderate evidence suggests a high short-term survival but possible dose-response trend of worsening BOP and MBL in association with glycemic control. Clinically, HbA1c values must be considered for risk assessment before placement and throughout the lifespan of the implant placed in a patient with diabetes.
