Morphological Characteristics of Mandibular Molar Furcation Involvement and Efficacy of Regenerative Surgical Treatment

Background and Objectives:Furcation involvement in multi-rooted teeth presents a significant challenge in periodontal therapy. Precise morphological diagnosis using 3D imaging (CBCT) and effective regenerative strategies are essential to improve tooth prognosis. This study aims to: Determine the prevalence and morphological characteristics of furcation defects in mandibular molars (Cross-sectional component). Compare the diagnostic accuracy of CBCT imaging with direct intra-operative clinical measurements obtained during surgical access (Interventional component). Evaluate and compare the clinical and radiographic efficacy of regenerative periodontal surgery using Acellular Dermal Matrix (ADM) combined with Enamel Matrix Derivative (EMD) and xenograft versus Autogenous Connective Tissue Graft (CTG) combined with EMD and xenograft in Hamp Class II furcation defects at 6 months post-operatively. Study Design and Workflow:Component 1 (Cross-Sectional Screening): Stage III/IV periodontitis patients presenting to the Dental Clinic at the Faculty of Odonto-Stomatology, University of Medicine and Pharmacy at Ho Chi Minh City will be evaluated for the prevalence and morphological features of furcation defects. Component 2 (Randomized Controlled Trial): Following non-surgical periodontal therapy and re-evaluation, 30 patients with residual Hamp Class II furcation defects will be randomly assigned into two treatment groups: Experimental Group: Open flap debridement, placement of xenograft, Acellular Dermal Matrix (ADM), and Enamel Matrix Derivative (EMD). Active Comparator Group: Open flap debridement, placement of xenograft, Autogenous Connective Tissue Graft (CTG), and Enamel Matrix Derivative (EMD). Follow-up: Intra-operative clinical measurements will be compared with pre-operative CBCT scans. Clinical parameters (PPD, CAL) and radiographic bone fill (via CBCT) will be evaluated at baseline and 6 months post-operatively.

Inclusion criteria

• Patients aged 18 years or older who signed the informed consent form.
• Diagnosed with Stage III or Stage IV periodontitis according to the 2017 AAP/EFP classification.
• Completed non-surgical periodontal therapy with full-mouth plaque score (FMPS) and bleeding on probing (FMBS) <= 20%.
• Presence of at least one mandibular molar with Hamp Class II furcation involvement (horizontal bone loss > 3 mm without through-and-through communication).
• Target tooth requirements:

• Probing pocket depth (PPD) >= 5 mm.
• Clinical attachment loss (CAL) >= 3 mm.
• Tooth mobility <= Grade I (Miller index).
• Vital pulp or adequately filled root canal treatment without periapical radiolucency.
• Gingival margin positioned coronal to the furcation entrance.
• Intact tooth structure without root fractures or furcation caries.

Exclusion criteria

• Uncontrolled systemic diseases (e.g., uncontrolled diabetes, hypertension, cardiovascular disease, severe osteoporosis).
• Pregnant or lactating women.
• Current smokers or individuals who quit smoking less than 6 months prior to enrollment.
• Use of antibiotics, anti-inflammatory agents, or medications affecting bone metabolism (e.g., bisphosphonates, high-dose corticosteroids, anti-resorptive drugs) within the past 3 months.
• Previous periodontal surgery at the evaluation site within the past 6 months.
• Target teeth presenting with:

• Miller Grade II or Grade III tooth mobility.
• Severe bone destruction extending to the root apex.
• Metallic restorations (metal crowns, amalgam fillings, or large metallic posts) causing significant scatter/artifacts on CBCT scans.
• Fused roots or abnormal root anatomy.