The goal of this clinical trial is to test in 10 patients with advanced furcation involvement on molars. The main question[s] it aims to answer are:

• Is it possible to carry out root resection without endodontic treatment on molars? Tooth vitality will be checked (positive response to cold test). Root resection will be carried out under local anestesia.

Following visits will be carried out for re-evaluation/maintenance according to clinical care every 3 mounths until 3 years follow-up.

Inclusion Criteria:

• Patient diagnosed with stage III-IV periodontitis
• Compliantpatient, as shown by full mouth plaque score<30%
• Previous non-surgical periodontal therapy within 6 mounths
• Maxillary or mandibular molar affected by periodontal furcation involvement and scheduled for root resection
• Positive to sensibility testing (cold/electric pulp tests)
• No prosthesis or large restorations
• Sufficiently divergent roots to make root resection feasible
• Root trunk lenght at 3 mm as measured in periapical radiograph

Exclusion Criteria:

• Systemic contraindications to perform periodontal surgery/root resection
• Fused roots
• Presence of periapical radiolucency
• Furcation class III affecting all roots of maxillary molar