The aim is of this study is to evaluate and compare the effects (clinical and radiological) of different biomaterials on the repair of bone defects around the teeth. When participating in this study, persons will be scheduled for local surgical intervention of the gums. Under local anaesthesia, the gums will be opened minimally to gain insight into the underlying bone defect. After the bone defect has been made completely free of inflammation, they will be randomly assigned to one of the groups below and the biomaterials for this group will be used to fill the defect around your teeth. The different biomaterials are artificial bone + amelogenin; artificial bone + hyaluronic acid; artificial bone + blood preparation (L-PRF) or blood preparation alone.

Then the gums will be closed again with a suture and they will receive the necessary instructions regarding the procedure.

The purpose of this study is to assess the clinical and radiological effectiveness of hyaluronic acid (REGENFAST®), enamel matrix derivative (Emdogain®), and platelet concentrates (L-PRF) in the surgical treatment (minimally invasive technique) of intra-bony defects in conjunction with minimally invasive surgery..

This is a non-inferiority study. The alternative hypothesis is that the use of hyaluronic acid or L-PRF obtained at least the same treatment outcome (seen as clinical attachment level gain) than the gold standard (use of enamel matrix derivatives).

2.2. Primary Endpoints

Post-operative changes in clinical attachment level (CAL):

• difference between the baseline and 6/12 months after the surgery
• measured in millimetres

2.3. Secondary Endpoints

Post-operative changes in probing pocket depth (PPD):

• difference between the baseline and 6/12 months after the surgery
• measured in millimetres

Post-operative changes in papilla height (preservation of soft tissues):

• difference between the baseline and 6/12 months after the surgery
• measured by means of a volumetric analysis based on intra-oral scan

Post-operative changes in intra-bony defect morphology:

• difference between the baseline and 6/12 months after the surgery
• periapical radiograph (parallel angle technique)
• defect resolution measured in millimetres
• bone fill measured in percentage

Inclusion Criteria:

• Voluntary written informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedures
• At least 18 years of age at the time of signing the Informed Consent Form (ICF)
• American Society of Anesthesiology (ASA) score I or II
• Has already completed the non-surgical periodontal therapy with remaining local pockets of ≥ 6 mm14
• The intra-bony defect should be non-contained (2-wall defect)
• Clinical indication for surgical treatment of the intra-bony defect with minimally invasive approach in conjunction with biologicals

Exclusion Criteria:

• Under the age of 18 years
• Any disorder, which in the Investigator's opinion might jeopardise the participant's safety or compliance with the protocol
• Any prior or concomitant treatment(s) that might jeopardise the participant's safety or that would compromise the integrity of the Trial
• Participation in an interventional Trial with an investigational medicinal product (IMP) or device
• Known or suspected current malignancy
• History of chemotherapy
• History of radiation in the head and neck region
• History of other metabolic bone diseases
• Current or previous use of intravenous and oral bisphosphonates
• Haematological disorders
• Pregnancy / lactation
• Smoking