Some research studies have demonstrated that autologous micrografts made out of different oral tissues may enhance tissue regeneration. The primary aim of this study is to evaluate the clinical performance of a combined approach using an autologous micrograft derived from the palatal mucosa with an alloplastic scaffold for periodontal regeneration of intrabony defects in terms of clinical attachment level gain (primary outcome) and other secondary outcomes (probing pocket depth reduction, radiographic bone fill) compared to a scaffold alone. Moreover, this study aims to compare early wound healing and patient-reported outcome measures between the two groups.

Patients selected for the study should fulfil the following inclusion criteria:

• Affected from stage III-IV periodontitis.
• Completed non-surgical periodontal therapy.
• FMPS <15% at 3-month re-evaluation.
• FMBS <15% at 3-month re-evaluation.
• At least one site with an interproximal intrabony defects and residual PPD ≥ 6 mm at re-evaluation, with a radiographic intrabony component ≥ 3 mm, extending to the lingual/palatal side as assessed by preoperative bone sounding.
• Intrasurgically, the defect has to present a non-supporting anatomy (1-2 residual walls in its most coronal portion), requiring flap elevation on both buccal and oral side for its accessibility.
• Signed informed consent.

Exclusion criteria:

• Compromised general health which contraindicates the study procedures (ASA III-VI patients).
• Systemic diseases/medications which could influence the outcome of the therapy (e.g. uncontrolled diabetes mellitus, non-plaque-induced gingival diseases, antiepileptic drugs (phenytoin and sodium valproate), certain calcium channel-blocking drugs (e.g., nifedipine, verapamil, diltiazem, amlodipine, felodipine), immunoregulatory drugs (e.g., cyclosporine), and high-dose oral contraceptives.
• Current smokers (self-reported), users of chewing tobacco, and drug/alcohol abusers.
• Pregnant or nursing women.
• Presence of furcation involvement ≥ II degree (Hamp 1975) at the affected teeth.
• Very large and wide defects that required the use of membrane.