REGENERATIEF POTENTIEEL VAN BLADBLOKKENCONCENTRATEN IN DE TANDHEELKUNDE

Platelet concentrates are blood-derived products containing a high concentration of platelets, which are cells responsible for coagulation and various functions in tissue repair. In recent years, various uses have been explored in dentistry with the aim of regenerating soft and hard tissues. The general aims was to evaluate different characteristics of PRF matrices and their potential regenerative effect using them as a sole material or combined with other grafts in different oral clinical and surgical procedure. This objective was developed through various in vitro and clinical studies that addressed the following hypotheiss and research questions: 1. In vitro studies: -Hypothesis 1.1: L-PRF membrane characteristics (cellular content, mechanical properties, release of growth factors) are influenced by gender and blood parameters. RQ 1.1: Do gender and blood parameters have an influence on the L-PRF membrane characteristics? -Hypothesis 1.2: The release of growth factors and antibacterial effect are higher from the face of the L-PRF membrane (zone closest to the red blood cells) compared with the body (remaining part of L-PRF membrane). RQ 1.2: Are there significant differences in the release of growth factors and antimicrobial effect between the face and body of the L-PRF membrane? -Hypothesis 1.3: The addition of metronidazole to L-PRF improves the antimicrobial effect against periodontal pathogens but decreases the release of growth factors. RQ 1.3: Does the addition of metronidazole to L-PRF have an impact on the antimicrobial effect against periodontal pathogens and in the release of growth factors? -Hypothesis 1.4: The physico-chemical characteristics of dental implants modify their interaction with liquid fibrinogen. RQ 1.4: Do the physico-chemical characteristics of a dental implant surface affect its interaction with liquid fibrinogen? -Hypothesis 1.5: The centrifuge type, and the time before or after centrifugation do not have any influence on the characteristics of platelet concentrates (L-PRF, A-PRF and A-PRF+). RQ 1.5: Do the centrifuge type and time before/after centrifugation affect the biological (cell content, growth factor release), morphological (size), and mechanical properties of platelet concentrates (L-PRF, A-PRF and A-PRF+)? 2. Clinical studies: -Hypothesis 2.1: L-PRF membranes have the same beneficial effect as a connective tissue graft during a coronally advanced flap (CAF) for the treatment of Miller class I and II localized gingival recession. RQ 2.1: What are the effects in clinical parameters and post-operative pain/complications of L-PRF membranes compared with a connective tissue graft during a CAF for the treatment of Miller class I and II localized gingival recession? -Hypothesis 2.2: L-PRF membranes applied after Non-surgical Periodontal Treatment significantly improve the clinical parameters and the periodontopathogen concentrations in deep periodontal pockets (≥6 mm). RQ 2.2: Do L-PRF membranes adjunct to Non-surgical Periodontal Treatment significantly improve the clinical parameters and the concentration of periodontopathogens in deep periodontal pockets (≥6 mm), in patients with Periodontitis? -Hypothesis 2.3: L-PRF membranes combined with liquid fibrinogen and particulate dentin (Dentin block) are a predictable matrix for alveolar ridge preservation RQ 2.3: Are L-PRF membranes combined with liquid fibrinogen and particulate dentin (Dentin block) an alternative bone substitute for alveolar ridge preservation with an adequate bone formation after 4, 5, or 6 months of healing?