Characterization of the Leukocyte- and Platelet-Rich Fibrin Block: Release of Growth Factors, Cellular Content, and Structure.

PURPOSE: The leukocyte- and platelet-rich fibrin block (L-PRF block) is a composite graft that combines a xenograft that is acting as a scaffold with L-PRF membranes that serve as a bioactive nodule with osteoinductive capacity. This study evaluated the properties of the L-PRF block and its components in terms of release of growth factors, cellular content, and structure. MATERIALS AND METHODS: The concentration of transforming growth factor-ß1 (TGF-ß1), vascular endothelial growth factor (VEGF), platelet-derived growth factor-AB (PDGF-AB) and bone morphogenetic protein-1 (BMP-1) released by a L-PRF membrane (mb) and a L-PRF block were examined with ELISA for five time intervals (0 to 4 hours, 4 hours to 1 day, 1 to 3 days, 3 to 7 days, 7 to 14 days). Those levels in L-PRF exudate and liquid fibrinogen were also evaluated. The cellular content of the liquid fibrinogen, L-PRF membrane and exudate was calculated. The L-PRF block was also analyzed by means of a microCT scan and scanning electron microscopy (SEM). RESULTS: TGF-ß1 was the most released growth factor after 14 days, followed by PDGF-AB, VEGF, and BMP-1. All L-PRF blocks constantly released the four growth factors up to 14 days. L-PRF membrane and liquid fibrinogen presented high concentration of leukocytes and platelets. The microCT and SEM images revealed the bone substitute particles surrounded by platelets and leukocytes, embedded in a dens fibrin network. CONCLUSION: The L-PRF block consists of deproteinized bovine bone mineral particles surrounded by platelets and leukocytes, embedded in a fibrin network that releases growth factors up to 14 days.

Leucocyte- and platelet-rich fibrin block for bone augmentation procedure: A proof-of-concept study.

AIM: The objective of this proof-of-concept study was to investigate the effects of a new guided bone regeneration technique with a tissue engineering approach. MATERIALS AND METHODS: This single cohort observational study evaluated the outcome of the leucocyte- and platelet-rich fibrin (L-PRF) Block for horizontal bone augmentation in the maxilla. The L-PRF Block is prepared by mixing a particulated biomaterial with chopped L-PRF membranes at a 50:50 ratio and adding liquid fibrinogen to glue all together. Horizontal augmentation was assessed linearly and volumetrically immediately after surgery and 5-8 months later by matching consecutive cone beam computed tomography (CBCTs). RESULTS: Ten patients (mean age of 50.7 years [±17.2]) representing 15 sites with horizontal alveolar deficiencies were included. Superimposition of pre-operative and posthealing CBCT scans showed an average linear horizontal bone gain of 4.6 mm (±2.3), 5.3 mm (±1.2) and 4.4 mm (±2.3), measured at 2, 6 and 10 mm from the alveolar crest, respectively. The volumetric gain was 1.05 cm3 (±0.7) on average. The resorption rate after 5-8 months was 15.6% (±6.7) on average. CONCLUSIONS: L-PRF Block may be a suitable technique to augment deficient alveolar ridges.

Regenerative potential of leucocyte- and platelet-rich fibrin. Part A: intra-bony defects, furcation defects and periodontal plastic surgery. A systematic review and meta-analysis.

AIM: To analyse the regenerative potential of leucocyte- and platelet-rich fibrin (L-PRF) during periodontal surgery. MATERIALS AND METHODS: An electronic and hand search were conducted in three databases. Only randomized clinical trials were selected and no follow-up limitation was applied. Pocket depth (PD), clinical attachment level (CAL), bone fill, keratinized tissue width (KTW), recession reduction and root coverage (%) were considered as outcome. When possible, meta-analysis was performed. RESULTS: Twenty-four articles fulfilled the inclusion and exclusion criteria. Three subgroups were created: intra-bony defects (IBDs), furcation defects and periodontal plastic surgery. Meta-analysis was performed in all the subgroups. Significant PD reduction (1.1 ± 0.5 mm, p < 0.001), CAL gain (1.2 ± 0.6 mm, p < 0.001) and bone fill (1.7 ± 0.7 mm, p < 0.001) were found when comparing L-PRF to open flap debridement (OFD) in IBDs. For furcation defects, significant PD reduction (1.9 ± 1.5 mm, p = 0.01), CAL gain (1.3 ± 0.4 mm, p < 0.001) and bone fill (1.5 ± 0.3 mm, p < 0.001) were reported when comparing L-PRF to OFD. When L-PRF was compared to a connective tissue graft, similar outcomes were recorded for PD reduction (0.2 ± 0.3 mm, p > 0.05), CAL gain (0.2 ± 0.5 mm, p > 0.05), KTW (0.3 ± 0.4 mm, p > 0.05) and recession reduction (0.2 ± 0.3 mm, p > 0.05). CONCLUSIONS: L-PRF enhances periodontal wound healing.

The impact of autologous platelet concentrates on endodontic healing: a systematic review.

The current literature was reviewed to determine the impact of autologous platelet concentrates (APCs) on endodontic healing. All types of clinical study designs concerning any kind of endodontic treatment involving the application of APCs were included. Two independent reviewers searched three databases (PubMed, Embase, and Cochrane Library) for studies, complemented by hand search, until 16/1/2016. From the 423 identified records, 48 articles met the inclusion criteria. Selected randomized controlled clinical trials (RCTs) underwent Cochrane Collaboration's risk-of-bias assessment and data extraction. Only two RCTs showed low risk of bias. There was considerable heterogeneity between the RCTs with regard to the type of therapy, type of APCs, assessment method, and study quality, and therefore the data could not be analyzed quantitatively. The included case reports/series and non-randomized comparative studies underwent qualitative analysis with the revised Methodological Index for Non-Randomized Studies (MINORS) and data extraction. The two comparative non-randomized studies scored qualitatively high, though the MINORS-scores of the case series and reports were dispersed. APCs were involved in five endodontic treatment modalities, namely apexification, regenerative endodontic procedures, pulpotomy, apical surgery, and treatment of endo-perio/perio-endo lesions. APCs seem to accelerate postoperative bone healing, augment the patients' postoperative quality of life, aid further root development, and support maintenance/regaining of pulp vitality. No adverse events were reported. APCs in endodontic treatments seem to contribute to the healing of soft and hard tissues, though there is a lack of long-term high quality clinical trials and standardized treatment protocols.