Minimally-invasive Non-surgical Treatment in Teeth With Unfavourable Prognosis

Inclusion Criteria: * Age 18-70 * Diagnosis of Periodontitis stage III or IV (grade A, B or C) (Tonetti et al. 2018) * Presence of: * N=10: Maxillary or mandibular molars with: A. Furcation involvement degree II C based on Hamp et al. 1975 horizontal classification and Tarnow \& Fletcher 1984 vertical classification (with concomitant furcation involvement (FI) not exceeding degree II on the other aspects of the same tooth) B. gingival recession ≤ 2mm on furcation site C. mobility maximum degree 2 * N=10: 'Teeth with bone loss to the apex' (also defined as 'hopeless' by Cortellini et al. 2011), defined as having: A. radiographic bone loss to the apex or beyond the apex on at least one inter-dental aspect B. presence of severe attachment loss (\>10 mm) at the same inter-proximal site/s and at least at one of either the buccal or lingual aspect (Cortellini et al. 2011) C. lack of function because of hypermobility, and/or lack of chewing strength, and/or pain, and/or recurrent periodontal infection/abscesses (Cortellini et al. 2011) D. positive response to vitality testing with electric pulp test (EPT) or previous endodontic treatment considered satisfactory, as judged by the examining clinician \- Willing to sign informed consent to take part in the study Exclusion Criteria: * Smoking (any current or in past 5 years) * Medical history including diabetes or hepatic or renal disease, or other serious medical conditions or transmittable disease * History of conditions requiring prophylactic antibiotic coverage prior to invasive dental procedures * Anti-inflammatory or anticoagulant therapy during the month preceding the baseline exam * Systemic antibiotic therapy during the 3 months preceding the baseline exam * History of alcohol or drug abuse, vii) Self-reported pregnancy or lactation * Other severe acute or chronic medical or psychiatric condition or laboratory abnormality that according to the investigator may increase the risk associated with trial participation * Periodontal treatment to the study site within the last 12 months