The Use of Two Bone Substitutes in Adjunct to EMD for the Treatment of One- and Two-wall Intrabony Defects.

Inclusion Criteria: * Men and women over or equal to the age of 18 years * Patients in general good health in the opinion of the principal investigator as determined by medical history and clinical examination (ASA 1 or ASA-2) * Clinical evidence of periodontitis, with one interdental area of PPD (periodontal probing depth) ≥6mm and bleeding on probing, associated one or more one-wall or two-wall intrabony periodontal defect with an intrabony component of equal or more than 3 mm, as diagnosed by periapical radiographs and clinical evaluation (excluding third molars and distal of second molars); the defect must not affect the vestibular / buccal or the lingual support bone wall (PPD lingual or vestibular / buccal \<= 3.5 mm ) of the affected teeth. * Patients who already underwent stage I and stage II of periodontal therapy, as described in the EFP practice guidelines (Sanz et al., 2020), within 6 months prior to assessment for eligibility * Patients who can understand the requirements of the study and are willing and able to comply with its instructions and schedules * Patients who had provided written informed consent to participate in the study prior to any study procedure. Exclusion Criteria: * FMPS% \> 15% at the time of recruitment * FMBS% \> 15% at the time of recruitment * Treatment with anticoagulant drugs (INR above 2,5) * Treatment with intravenous bisphosphonates * Treatment with anticonvulsants drugs * patients with history of alcohol, narcotics, or drug abuse * Patients receiving radiotherapy, chemotherapy, or any other immunosuppressive treatment or who have been administered radiotherapy in the last 5 years * Patients through at any time received radiotherapy to the head and neck region will be excluded anyway * Uncontrolled bleeding disorders such as: hemophilia, thrombocytopenia, granulocytopenia * Degenerative diseases * Osteoradionecrosis * Renal failure * Organ transplant recipients * HIV positive (self-declaration) * Malignant diseases * Diseases that compromise the immune system * Unbalanced diabetes. (HbA1c above 7.2 assessed by self-declaration) * Psychotic diseases * Hypersensitivity or specific contraindications to one of the components of any of the products used in the study * Women who are pregnant (self-declaration); or lactating at the time of recruitment and of surgery * Site where a history of failed periodontal regenerative procedure in the last two years * Heavy Smokers (5 cigarettes and more per day) * Other uncontrolled systemic diseases * disorders or treatments that compromise wound healing * chronic high dose steroid therapy * bone metabolic diseases