Effect of Molar Replacement on Glycemic Control in Adults With Uncontrolled Type 2 Diabetes

Type 2 diabetes (T2D) is a major global health issue, affecting about 9.2% of adults in Europe. Although treatment begins with lifestyle changes and medications, up to half of patients fail to achieve adequate blood sugar control, highlighting the need for new strategies. People with T2D often have poorer oral health, including missing teeth and more severe periodontal disease. This reduces masticatory (chewing) efficiency, which depends largely on having functional molars. Impaired chewing can influence food choices and overall diet quality. This study explores whether improving chewing ability by replacing missing molars can help patients with uncontrolled T2D improve their diet and blood sugar levels. The hypothesis is that restoring masticatory efficiency with implant-supported prostheses will lead to healthier eating habits and better glycemic control. This study is a multicenter, randomized controlled trial with two groups: * Intervention group: receives molar replacement with implant-supported prostheses plus standard diabetes care. * Control group: receives standard diabetes care only. The main goal is to assess the effect of this intervention on glycemic control after 9 months, measured by changes in HbA1c levels. All participants will receive a comprehensive oral health assessment and necessary dental care (e.g., treatment of infections, cavities, and periodontal disease), which may itself improve quality of life and potentially support better diabetes control by reducing inflammation. For the intervention group, restoring molars is expected to improve chewing efficiency, enhance quality of life, and encourage healthier dietary habits, which could improve diabetes outcomes. Additionally, since poor chewing ability is linked to higher cardiovascular risk, the intervention may also help reduce heart disease risk.

Inclusion Criteria: * Adults aged between 18 and 75 years * Type 2 diabetes diagnosed for more than 6 months, according to the diagnostic criteria of the International Diabetes Federation * Insufficiently controlled type 2 diabetes (HbA1c between 7.5% and 10.5%) * Type 2 diabetes under stable treatment for at least 3 months (no initiation or discontinuation of antidiabetic treatments, and no change in basal insulin dose greater than ±50% compared with the initial dose) * Presence of all teeth up to the second premolars, i.e. presence of maxillary and mandibular incisors, canines and premolars. The absence of premolars extracted for orthodontic reasons or due to agenesis is not taken into account. Teeth replaced by fixed tooth- or implant-supported prostheses are considered present. * Absence of functional molar pairs not compensated by a partial prosthesis, or presence of only one functional molar pair. The absence of a pair may be due to the absence of both molars or only one molar (molar without an antagonist). Third molars are not taken into account. Exclusion Criteria: * Recent diabetes (\< 6 months), intensified insulin therapy (≥ 3 injections/day) or insulin pump use * Type 1 diabetes * Type 2 diabetes with HbA1c \> 10.5% * Comorbidities contraindicating part of the oral rehabilitation (particularly implant placement) or impacting masticatory efficiency, such as end-stage renal disease or stroke within the past 6 months * Smoking \>10 cigarettes/day * Presence of severe crestal defects, insufficient prosthetic space, malocclusions and/or parafunctions contraindicating part of the oral rehabilitation * Severe periodontitis (Stage III or IV, Grade C) * Cancerous or precancerous lesions of the oral mucosa * Allergy to anesthetics or antibiotics required for dental surgery * Pregnant or breastfeeding woman * Participation in another interventional study involving human participants or being within the exclusion period following a previous study involving human participants, where applicable * No affiliation to a social security scheme * Patient benefiting from State Medical Aid (AME) * Individual deprived of liberty or under legal protection measures * Refusal or inability to provide written informed consent