Mechanical, chemical, structural analysis and comparative release of PDGF-AA from L-PRF, A-PRF and T-PRF - an in vitro study

Abstract Background Platelet concentrates have been popularly used in regenerative periodontal therapy as they are autologous in origin and they provide a supernatural concentration of platelets, growth factors and leukocytes. The release profile of various growth factors is considered important during the various phases of wound healing with the most important being the inflammatory phase where the release of the growth factors help in recruitment of cells and in collagen production. With the more recent modifications of PRF namely A-PRF and T-PRF, the mechanical and chemical degradation properties have also improved. The aim of the present study was to correlate the release profile of PDGF-AA from various forms of platelet concentrates (L-PRF, A-PRF, T-PRF) based on their mechanical and chemical properties. Methods Blood samples were drawn from 2 male and 3 female systemically healthy patients between 20 and 25 years of age who were about to undergo periodontal regeneration for PRF preparation. The blood sample was immediately centrifuged using a table top centrifuge (Remi R4C) at 1060 rpm (208 x g) for 14 min for A-PRF preparation, 1960 rpm (708 x g) for 12 min for L-PRF preparation and 1960 rpm (708 x g) for 12 min in titanium tubes for T-PRF preparation. Tensile test was performed using universal testing machine. The in vitro degradation test of the prepared PRF membranes were conducted by placing the PRF membrane in 10 ml of pH 7.4 PBS on an orbital shaker set at 50 rpm. SEM evaluation of the PRF membrane was done under both low and high magnification. In order to determine the amount of released growth factor PDGF-AA at 15 min, 60 min, 8 h, 1 day, 3 days, and 10 days, samples were placed into a shaking incubator at 37 °C to allow for growth factor release into the culture media. Results On comparing the three PRF membranes, it was found that T-PRF contained the maximum tensile strength (404.61 ± 5.92 MPa) and modulus of elasticity (151.9 ± 6.92 MPa). Statistically significant differences between the three groups were found on comparing the groups for their mechanical properties. In the degradation test, it was found that the maximum amount of degradation was found in L-PRF (85.75%), followed by A-PRF (84.18%) and the least was found in T-PRF (82.27%). T-PRF released the highest amount of PDGF-AA (6060.4 pg/ml) at early time points when compared to A-PRF (5935.3 pg/ml). While T-PRF had rapid release of PDGF-AA, A-PRF had a sustained release of growth factors released at later time points. Conclusion Results from the present study indicate that A-PRF is the most favourable form of platelet concentrate in regenerative periodontal therapy as it has a sustained release of growth factors over time. </jats:sec

Mechanical, chemical, structural analysis and comparative release of PDGF-AA from L-PRF, A-PRF and T-PRF - an in vitro study

Abstract Background Platelet concentrates have been popularly used in regenerative periodontal therapy as they are autologous in origin and they provide a supernatural concentration of platelets, growth factors and leukocytes. The release profile of various growth factors is considered important during the various phases of wound healing with the most important being the inflammatory phase where the release of the growth factors help in recruitment of cells and in collagen production. With the more recent modifications of PRF namely A-PRF and T-PRF, the mechanical and chemical degradation properties have also improved. The aim of the present study was to correlate the release profile of PDGF-AA from various forms of platelet concentrates (L-PRF, A-PRF, T-PRF) based on their mechanical and chemical properties. Methods Blood samples were drawn from 2 male and 3 female systemically healthy patients between 20 and 25 years of age who were about to undergo periodontal regeneration for PRF preparation. The blood sample was immediately centrifuged using a table top centrifuge (Remi R4C) at 1060 rpm (208 x g) for 14 min for A-PRF preparation, 1960 rpm (708 x g) for 12 min for L-PRF preparation and 1960 rpm (708 x g) for 12 min in titanium tubes for T-PRF preparation. Tensile test was performed using universal testing machine. The in vitro degradation test of the prepared PRF membranes were conducted by placing the PRF membrane in 10 ml of pH 7.4 PBS on an orbital shaker set at 50 rpm. SEM evaluation of the PRF membrane was done under both low and high magnification. In order to determine the amount of released growth factor PDGF-AA at 15 min, 60 min, 8 h, 1 day, 3 days, and 10 days, samples were placed into a shaking incubator at 37 °C to allow for growth factor release into the culture media. Results On comparing the three PRF membranes, it was found that T-PRF contained the maximum tensile strength (404.61 ± 5.92 MPa) and modulus of elasticity (151.9 ± 6.92 MPa). Statistically significant differences between the three groups were found on comparing the groups for their mechanical properties. In the degradation test, it was found that the maximum amount of degradation was found in L-PRF (85.75%), followed by A-PRF (84.18%) and the least was found in T-PRF (82.27%). T-PRF released the highest amount of PDGF-AA (6060.4 pg/ml) at early time points when compared to A-PRF (5935.3 pg/ml). While T-PRF had rapid release of PDGF-AA, A-PRF had a sustained release of growth factors released at later time points. Conclusion Results from the present study indicate that A-PRF is the most favourable form of platelet concentrate in regenerative periodontal therapy as it has a sustained release of growth factors over time

Surgical augmentation of interdental papilla - A case series

Formation of black triangles between teeth due to loss of interdental palpilla is one of the common problems encountered in routine clinical practice, as extreme importance is given to esthetics. This paper discusses two different surgical approaches in treating three cases with papillary loss in the first case the reconstruction of papilla was achieved by using a semilunar coronally repositioned papilla technique and in second and the third case reconstruction of the papilla was achieved by modification of Nodland's microsurgical technique. In all the three cases a free connective tissue graft was used to reconstruct the lost volume of interdental papilla. Complete reconstruction of the lost papilla was achieved in all the three cases 6 months postoperatively

Expression of protease-activated receptors 1 and 2 in individuals with healthy gingiva and chronic periodontitis

Background: Protease-activated receptors (PAR-1 and PAR-2) are found to be immensely exhibited in the periodontal tissues. These receptors are involved in the inflammatory and repair processes. Activation of PARs is mainly by the bacterial and endogenous enzymes. The aim of the study was to determine the role of PAR-1 and PAR-2 in initiating periodontal inflammation and to immunolocalize these receptors in the gingival tissues of healthy and chronic periodontitis individuals. Materials and Methods: A total of 50 patients were selected for this study, of which 25 were healthy controls and 25 were chronic periodontitis patients. Gingival tissues were excised from the marginal gingiva and interdental papilla under local anesthesia (xylocaine with 2% adrenaline) during crown lengthening procedure or during periodontal therapy depending on the respective groups. Immunohistochemical analyses of PARs were done by staining the samples with hematoxylin and eosin and with primary and secondary antibody for PAR-1 and PAR-2. Results: The Hematoxylin and Eosin staining showed more inflammatory changes in the periodontitis group compared to healthy gingiva. In chronic periodontitis, PAR-1-positive cells were seen in the basal layer with a weak expression and were showing negative expression in the superficial layer. In consideration of PAR-2, there was a very strong expression up to the superficial layer of the epithelium, compared to PAR-1. On comparing the intensity of staining in the connective tissue of chronic periodontitis sample, there was an increased expression of PAR-2 compared with PAR-1. A low positive expression of PAR-1 and PAR-2 was observed in the epithelium and connective tissue of the healthy tissues. Conclusion: The results clearly demonstrated the role of PAR-1 and 2 in periodontal inflammation

A case-control study assessing depression in patients with periodontitis

Background: Chronic periodontitis is an inflammatory disease of the supporting structures of the tooth. One of the important non-oral risk factors for periodontitis is psychosocial stress and depression. Depression affects oral health by affecting the immune system through its effects on hypothalamic pituitary axis system. Periodontal inflammatory surface area (PISA) is a system used to assess inflammatory burden in the periodontal tissue. Aim: The aim of this study is to assess the relationship between PISA and depression. Settings and Design: The design of the study is case-control study. Materials and Methods: The study design is a case-control study with forty patients each in case and control groups. The periodontal inflammatory level was assessed by PISA system and the levels of depression was assessed by using Beck's Depression Inventory (BDI). Statistical Analysis: Student's t-test was used to compare PISA and BDI scores. The BDI score (mean ± standard deviation [SD]) for controls was 12.75 ± 6.82 compared to 22.73 ± 4.40 for the cases. The comparison (t = 7.78) was statistically significant at P < 0.0001. The PISA score (mean ± SD) for controls was 210.47 ± 76.80 compared to the PISA score of 1069.50 ± 204.21 for cases which was statistically significant (t = 24.90; P < 0.0001). Results: Significantly higher BDI scores were observed in patients with chronic periodontitis than healthy controls. Conclusion: This study clearly reveals a significant association between the severity of depression and inflammatory burden

Relationship between interleukin 1α levels in the gingival crevicular fluid in health and in inflammatory periodontal disease and periodontal inflamed surface area: A correlative study

Background: Periodontitis has been suggested as a source of inflammation for pathological changes in distant sites. Interleukin-1 alpha (IL-1α) has shown to have specific roles in inflammation, immunity, tissue breakdown, and tissue homeostasis. This study assessed the correlation of periodontal inflamed surface area (PISA) index with the gingival crevicular fluid (GCF) levels of IL-1α, which would be helpful in evaluating the validity of PISA index in terms of reflection of the disease. Materials and Methods: A total of 40 subjects were recruited for this study and 20 subjects with healthy gingiva (Group I) served as controls and 20 subjects served as cases with periodontitis (Group II). Samples of GCF were obtained from one site in each patient by placing color-coded, calibrated, volumetric microcapillary pipettes extracrevicularly, and subjected to ELISA test. Results: There was a statistical significance for mean probing depth (PD) and periodontal epithelial surface area (PESA) (P < 0.01), mean bleeding on probing and PISA, IL-1α (P < 0.01) and PESA (P < 0.05) in Group I. Statistical significance was found between PISA and IL-1α in Group I (P < 0.01). A positive correlation was found in Group II between mean PD and mean attachment loss (P < 0.01), PISA, IL-1α and PESA (P < 0.01), PISA and IL-1α levels (P < 0.01) which was statistically significant. Conclusion: The inflammatory burden index was statistically significant in the periodontitis group correlating with higher IL-1α levels, which clearly indicates the validity of PISA index

Lip repositioning surgery for correction of excessive gingival display

Esthetic demands have considerably increased over the years in routine clinical practice. A pleasant smile can give supreme confidence to an individuals personality. However, a perfect smile is dictated by a perfect balance of the white (teeth) and pink (gingival) display. This balance can be managed different treatment modalities, which is based on proper diagnosis. This case report demonstrates a successful management of gummy smile with a lip-repositioning procedure in a patient with an incompetent upper lip. This was accomplished by removing a partial thickness strip of mucosa from the maxillary buccal vestibule and suturing the lip mucosa to the mucogingival line. This resulted in a narrower vestibule and restricted muscle pull, thereby resulting incompetent lips and reduced gingival display during smiling

Variations in Soft and Hard Tissues following Immediate Implant Placement versus Delayed Implant Placement following Socket Preservation in the Maxillary Esthetic Region: A Randomized Controlled Clinical Trial

Introduction. Although retrospective analysis has shown immediate placement of implants (IIP) in the maxillary esthetic zone showing promising outcomes compared to delayed placement of implants following socket preservation (DIP), a direct comparison in a prospective, well-designed randomized fashion with adequate power analysis between the two implant placement protocols is still lacking. This study is aimed at radiographically evaluating the effect of IIP after extraction as compared to implant placed in preserved sockets 4 months following extraction (DIP) in terms of changes in buccal plate thickness(CBT) after 6 months of healing and evaluation of pink esthetic score (PES) for assessment of soft tissue changes and patient-related outcome measures (PROMs) using visual analogue scale (VAS). Materials and Methods. 25 implants were placed immediately following extraction in the IIP group, and 25 implants were placed four months following socket preservation with demineralized bovine bone mineral (DBBM) and advanced platelet-rich fibrin (A-PRF) in the DIP group, control group, in the maxillary esthetic region. CBCT was taken preoperatively and 6 months postoperatively to assess the dimensional changes in the buccal bone plates(CBT). PES and PROMs for pain threshold and patient satisfaction using VAS were evaluated at the time of implant placement and 6 months postoperatively. Results. Significant differences in mean reduction in buccal plate thickness (CBT) were found in the test group (IIP) 0.2 ± 0.02 compared to the control group (DIP) which showed a mean reduction in CBT of 0.4 ± 0.1 ( p &lt; 0.001 ) at the end of 6 months. Although there was no statistically significant difference in PES between the groups, there was a significant difference between the groups when individual values of PES were compared at p &lt; 0.001 . Conclusion. The IIP group showed lesser reduction in CBT and a better PES which is an important clinical information which could be translated clinically in situations where implant placement is planned in the maxillary esthetic region. This trial is registered with CTRI/2019/06/019723.</jats:p