Comparison of the angiogenic efficacy of conventional leukocyte- and platelet-rich fibrin versus low-speed advanced platelet-rich fibrin: An in vitro chorioallantoic membrane assay study.

BACKGROUND: Platelet-rich fibrin (PRF) is widely used in periodontics for its wound healing potential. Two major variations of PRF are the original leukocyteand platelet-rich fibrin (L-PRF) and the modified lowspeed advanced PRF (A-PRF). OBJECTIVES: The aim of the present study was to evaluate and compare the conventional L-PRF protocol and the low-speed A-PRF protocol in terms of angiogenic potential of PRF, using an in vivo chorioallantoic membrane (CAM) assay. MATERIAL AND METHODS: Fifteen fertile Giriraja eggs were procured and after a 3-day incubation period, randomly allotted into 3 groups: control; L-PRF; and A-PRF. A total of 20 mL of blood was collected from systemically healthy male volunteers aged 18-24 years, using a standard protocol. The PRF samples were inoculated on the CAM of the eggs. On the 10th day, the eggs were reopened and photographed. The parameters assessed were the number, length, size, and density of blood vessels, as well as the number of junctions formed. The photographs were analyzed using the ImageJ and ProgRes® CapturePro software. RESULTS: Seven days after inoculation, both the A-PRF and L-PRF groups exhibited significantly better results than the control group in terms of the number (59.20 ±6.61 vs. 48.80 ±5.07 vs. 19.20 ±6.98), length (25,000 ±1,813.10 µm vs. 17,000 ±282.90 µm vs. 8,000 ±184.49 µm), size (230,000 ±15,054.00 µm2 vs. 200,000 ±8,295.27 µm2 vs. 150,000 ±4,105.16 µm2), and density (central: 9,100 ±296.78 vs. 5,370 ±272.42 vs. 1,420 ±564.36; peripheral: 9,094 ±400.14 vs. 3,370 ±479.39 vs. 5,420 ±746.73) of blood vessels, as well as the number of junctions formed (52 ±3.81 vs. 41 ±1.58 vs. 33 ±4.64), respectively. CONCLUSIONS: The angiogenic potential was increased by the exposure to both L-PRF and A-PRF. However, A-PRF demonstrated statistically significant benefits in terms of the number, length, size, and density of blood vessels, as well as the number of junctions formed in comparison with the control and L-PRF groups.

Advanced platelet rich fibrin demonstrates improved osteogenic induction potential in human periodontal ligament cells, growth factor production and mechanical properties as compared to leukocyte and platelet fibrin and injectable platelet rich fibrin.

OBJECTIVES: This cross-sectional invitro research aimed to compare and contrast the macroscopic and microscopic, mechanical and biochemical features of leukocyte-rich platelet-rich fibrin, advanced platelet-rich fibrin, and injectable platelet-rich fibrin. MATERIALS AND METHODS: In all, 150 samples were taken from males aged 18 to 25 with good systemic health (n = 50 each for i-PRF, A-PRF, and L-PRF). The samples were assessed for clot length, clot width, membrane length and width. Microscopic parameters assessed were the distribution of cells and fibrin structure. Mechanical tests were performed for tensile strength using a universal testing machine and growth factor analysis was performed for platelet derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and transforming growth factor (TGF)- ß on Days 1, 3 and 7 using commercially available ELISA kits. The osteogenic potential was analyzed in a culture of human periodontal ligament cells for 21 days using cell viability assay, alkaline phosphatase formation and alizarin red staining for mineralization. RESULTS: L-PRF demonstrates statistically superior clot length, width, weight, membrane length, width and weight in comparison to A-PRF (p < 0.05). L-PRF demonstrates a denser fibrin structure in comparison to A-PRF and i-PRF (p < 0.05). The cells in L-PRF are most commonly situated in the proximal of the clot where as they are distributed in the proximal and middle aspect for A-PRF(p < 0.05). A-PRF demonstrates the highest tensile strength followed by L-PRF (p < 0.05). When growth factor release was evaluated, A-PRF showed noticeably increased release of all growth factors, namely PDGF-BB, TGF-ß, and VEGF, in comparison to i-PRF and L-PRF (p < 0.05). On days 7 and 14, the cell viability of human periodontal ligament cells in co-culture with A-PRF was statistically substantially greater than that of L-PRF and i-PRF (p < 0.05). Alkaline phosphatase levels were statistically substantially higher in A-PRF, followed by i-PRF and L-PRF on days 14 and 21 (p < 0.05). After 21 days of culture, A-PRF treated cultures had much more Alizarin Red staining than L-PRF and i-PRF cultures did (p < 0.05). CONCLUSION: It was determined that although L-PRF exhibits greater size and weight in comparison to A-PRF and i-PRF, A-PRF has superior mechanical properties, increased growth factor releases of TGF-b, PDGF-BB, and VEGF as well as superior cell viability, alkaline phosphatase production, and mineralization on human periodontal ligament cells. CLINICAL RELEVANCE: Based on these findings, A-PRF can be recommended for improved delivery of growth factors and osteogenesis whereas L-PRF is better-suited for applications relying on the size of membrane.

Second-Generation Liquid Platelet Concentrates: A Potential Boon for Regenerative Dentistry.

Platelet concentrates have seen significant advancement in the field of biological surgical wound additives. The focus is now on second-generation platelet concentrates, which are completely autologous with no external additives. Unlike other platelet concentrates, liquid or injectable platelet-rich fibrin (i-PRF) is the only one that is obtained in a liquid form. This property widens the horizons for its application to virtually any medical field, including many uses in dentistry. Over the past several years, studies have proposed different variations of i-PRF, such as changes to the protocol by varying centrifugation time, g-force, and other factors. The liquid or injectable form of PRF also allows for other modifications, such as the addition of various biomaterials. This article reviews the current evidence and advancements regarding i-PRF and its potential future applications.

Second-generation Liquid Platelet Concentrates: A Literature Review.

Liquid or injectable platelet-rich fibrin (PRF) is a second-generation platelet concentrate that is completely autologous and free of external additives, like bovine thrombin and calcium chloride. Additionally, it is the only one to be obtained in a liquid form among the second-generation platelet concentrates. This allows for wide applications such as maximizing injections or mixing with biomaterials such as bone grafts or antibiotics. Since it was first introduced in 2015, several modifications of the original protocol have been proposed which aim at maximizing its biological and mechanical properties. This includes changes in centrifugation speed, time, and so on. The aim of this review is to summarize the various modifications of the injectable/liquid formation of PRF as well as to discuss the potential applications and future research direction.

In Vitro Evaluation of Osteoblast Response to the Effect of Injectable Platelet-rich Fibrin Coating on Titanium Disks.

AIM: Biomimetic implant surface coatings can improve osteoblast response and enhance osseointegration. This study aimed to assess the response of osteoblast-like cell line (MG-63) coating of injectable platelet-rich fibrin on titanium discs. MATERIALS AND METHODS: Injectable-PRF (i-PRF) was prepared by centrifugation of blood at 700 rpm for 3 minutes without any anti-coagulant in i-PRF tubes. Ten commercially pure titanium discs were divided into control groups comprising plain discs, and test group, titanium discs were coated with i-PRF. These were then added to the cultured MG-63 cells. Cell proliferation, alkaline phosphatase production, and mineralization were assessed in both groups at day 1, 7, 14, and 21. RESULTS: The cell proliferation, alkaline phosphatase production, and mineralization increased significantly from day 1 to day 21 in both test and control groups and was significantly higher in the test group than in control group at day 1, 7, 14, and 21 (p <0.001). CONCLUSIONS: Coating of titanium discs with i-PRF causes increased proliferation, alkaline phosphatase production, and increased mineralization at day 1, 7, 14, and 21 in MG-63 osteoblast-like cells. CLINICAL SIGNIFICANCE: Improved osteoblast proliferation and mineralization demonstrate enhanced activity on the surface of an implant, which in turn may lead to increased bone to implant contact and faster/ and/or enhanced osseointegration.

Immediate Ridge Augmentation Using Autogenous Tooth Root as a Block Graft in a Periodontally Hopeless Extraction Site: A Pilot Study.

The aim of the our study was to assess the efficacy of autogenous tooth root as a block bone graft in reconstructing the vertical and horizontal dimensions at periodontally hopeless extraction sites both clinically and radiographically. A total of 13 patients having a tooth with periodontally hopeless prognosis and indicated for extraction were included in the study. Following atraumatic extraction, the tooth was processed to create a decoronated cementum-free dentin block which was used to augment the extraction socket. The augmentation of periodontally hopeless socket with tooth block autograft resulted in a gain of clinical ridge width of 5.9 mm radiographically, the apico-coronal defect depth reduced up to 8.2 mm (P = .001), and a gain in ridge width of 5.8 mm postoperatively after 6 months (P = .001). The present study demonstrated the effectiveness of using tooth root as a block graft for ridge augmentation in the periodontally hopeless extraction site making it suitable for implant placement in future.

Maxillary Sinus Augmentation Using Hydraulic Pressure by Lateral Approach and Simultaneous Implant Placement: Clinicoradiographic Study.

The purpose of this study was to assess clinically and radiographically efficacy of maxillary sinus augmentation using hydraulic pressure in a lateral approach with immediate implant placement. In a total of 10 patients having less than 4 to 6 mm of subantral bone height, lateral approach sinus membrane elevation procedure was performed using hydraulic pressure with the help of a specialized water lift kit followed by grafting and simultaneous implant placement. Cone beam computed tomography analysis was used to assess the change in subantral bone height from baseline to the 6 months postoperatively. Radiographically, subantral bone height increased from 3.86 ± 1.423 mm at baseline to 15.49 ± 2.73 mm at 6 months postoperatively with a gain of 11.63 + 2.63 mm (P < 0.001). Thus, it is concluded that hydraulic pressure may be efficiently used in lateral sinus augmentation procedures along with simultaneous implant placement.

Biological activation of bone grafts using injectable platelet-rich fibrin.

Platelet-rich fibrin (PRF) is gaining acceptance as a bioactive surgical additive in regenerative dentistry. However, PRF has only been available in gel or membrane form and is not suitable for injection. Recently, however, a liquid, injectable PRF has been introduced. This paper introduces the concept of injectable PRF and discusses its applications for biologic activation of bone grafts.

An Update on the Protocols and Biologic Actions of Platelet Rich Fibrin in Dentistry.

Platelet rich fibrin (PRF) is a surgical biologic additive that is prepared by manipulation of autologous blood. It has now evolved to become one of the most widely used platelet concentrate in dentistry. It has almost replaced Platelet rich plasma (PRP) for usage owing to its advantages such as being 100% autogenous, easy technique, time and cost effectiveness, superior & prolonged growth factor release. It finds varied applications in dentistry including management of gingival recession, for guided bone regeneration in periodontal, peri-implant and endodontic bone defects. Since its inception in 2001 by Choukroun & co-workers, there has been in-depth research regarding its clinical applications, biologic actions, various technique modifications and optimizations. Several modifications of the conventional protocol like the advanced PRF, injectable PRF, PRF lysate and Titanium-prepared PRF. Hence, the aim of this article to review the biological properties of platelet rich fibrin and the advancement in the PRF technology since its inception.

Cortical lamina technique: A therapeutic approach for lateral ridge augmentation using guided bone regeneration.

BACKGROUND: The present study aimed at evaluating the efficacy of a novel technique, the bone lamina technique, in horizontal ridge augmentation clinically & radiographically using a combination of allogenic cortical shell, particulate xenograft and resorbable collagen membrane. MATERIAL AND METHODS: Localized horizontal ridge defects, in ten patients (6 male, 4 female), with bucco-palatal ridge width less than 5 mm were included in this study. Localised ridge augmentation was performed using bone lamina technique with mineralised allogenic shell of 1 mm thickness trimmed to the appropriate size using stereo-lithographic models and fixed to the recipient site with stainless steel micro-screws of 1 mm diameter. The space between the shell & host bone was filled with particulate xenograft followed by placement of collagen membrane and primary closure of the site. Clinical parameters including ridge width before & after flap reflection & radiographic (CBCT) ridge width measurements were recorded pre-operatively,and six months after the augmentation procedure. Results obtained were analysed statistically. RESULTS: The mean clinical ridge width before flap reflection (BFR), after flap reflection (AFR) & radiographically was 3.7 ± 0.74 mm, 2 ± 0.70 mm & 1.77 ± 0.71 mm respectively at baseline which increased to 6.8 ± 0.95 mm, 5.15 ± 0.98 mm & 4.90 ± 0.90 mm with a mean gain in ridge width of 3.1 ± 0.63 mm (p< 0.005), 3.15 ± 0.63 mm (p<0.005) & 3.13 ± 0.70 mm (p< 0.005) respectively. CONCLUSIONS: The present study demonstrates that bone lamina technique can be effective means of horizontal ridge augmentation and the use of mineralized allograft in combination with xenograft and collagen membrane leads to good amount of bone regeneration for subsequent implant placement. Key words:Dental implant, guided bone regeneration, horizontal ridge defect, ridge augmentation.

Influence of various factors on patient compliance after periodontal therapy: A pilot study.

BACKGROUND: Patient compliance is an important predictor of periodontal prognosis, therapy, and maintenance. Limited studies concentrate up on the factors which affect patient compliance. Thus, the aim of the study is to determine the relationship between sociodemographic data, patient's oral health awareness (OHA) and treatment satisfaction (TS) to patient compliance. MATERIALS AND METHODS: A total of 150 patients were subjected to a prevalidated questionnaire comprising of thirty questions. Questions covered different aspects such as sociodemographic data, OHA, and level of patient TS. Statistical analysis was done using mean, percentages, and Spearman's correlation coefficient. RESULTS: A sample of 150 people was included into the study of which 93 were females and 67 males with a mean age of 38 years. The total OHA scores when divided into three categories such as 5-7, 8-9, and >10 and plotted against number of missed appointments; the difference found was statistically significant (P < 0.001). The mean TS was divided into four subgroups of score >24, 25-27, 28-30, and >31 and then plotted against the average number of missed appointments, and the difference was found to be statistically significant (P < 0.001). The correlation between the OHA score and number of missed appointments was -0.59 (P < 0.001) and TS score and number of missed appointments was -0.40 (P < 0.001). CONCLUSION: Within the limitations of the study, it can be concluded that patient education, OHA, and TS are the variables that influence the patient compliance.

Neutrophil priming: Implications in periodontal disease.

Periodontal disease is a well-regulated response to bacterial infection directed by the inflammatory cells of the host immune system. The host response to injury or insult is implicated to be a vital feature of the majority of periodontal diseases. The excessive activation of neutrophils plays a role in the pathogenesis in diseases such as acute respiratory distress syndrome, rheumatoid arthritis, and periodontitis by contributing to inflammatory tissue injury. In the recent times, there has been a shift of paradigm from a hypo- to hyper-responsive/primed model of neutrophil dysfunction in periodontal etiopathogenesis. The aim of this review is to outline the mechanisms and effects of neutrophil priming, and thereafter, discuss the current controversy that exists regarding the role of primed neutrophils in periodontal etiopathogenesis.

Titanium particles in tissues from peri-implant mucositis: An exfoliative cytology-based pilot study.

BACKGROUND: To evaluate the presence of titanium particles in the peri-implant mucosa of unloaded single implants. MATERIALS AND METHODS: Forty participants with single unloaded implants were selected. They were divided equally into two groups: Group 1 with mild and Group 2 with moderate-to-severe peri-implant mucositis. Cytologic smears of peri-implant mucosa were obtained using cytobrush during second-stage surgery. RESULTS: Study states that 60% of participants of Group 2 were positive for titanium particles in peri-implant cytology. CONCLUSION: This study concludes that the titanium particles might be the initiators of the inflammation around implant.

Assessment of Intraobserver and Interobserver Agreement of a New Classification System for Retrograde Periimplantitis.

BACKGROUND: Retrograde periimplantitis (RPI) is the inflammatory disease that affects the apical part of an osseointegrated implant while the coronal portion of the implant sustains a normal bone-to-implant interface. The aim of the current study was to assess the intraexaminer and interexaminer reliability of a proposed new classification system for RPI. MATERIALS AND METHODS: After thorough electronic literature search, 56 intraoral periapical radiographs (IOPA) of implants with RPI were collected and were classified by 2 independent reviewers as per the new classification system into one of the 3-mild, moderate, and advanced-classes based on the amount of bone loss from the apex of the implant to the most coronal part as a percentage of the total implant length. The IOPAs were assessed twice by the same examiners and both were blinded to each other's observations. RESULTS: The intraobserver agreement ranged from 0.85 to 0.91, which falls under the category of almost perfect agreement. The interexaminer agreement was found to be 0.83, also considered as almost perfect agreement. CONCLUSION: The proposed classification shows good intraexaminer and interexaminer reliability and can be used for treatment planning and prognosis in cases of RPI.

Application of transtheoretical model to assess the compliance of chronic periodontitis patients to periodontal therapy.

BACKGROUND: The present cross-sectional survey study was conducted to assess whether the transtheoretical model for oral hygiene behavior was interrelated in theoretically consistent directions in chronic periodontitis patients and its applicability to assess the compliance of the chronic periodontitis patients to the treatment suggested. MATERIALS AND METHODS: A total of 150 chronic periodontitis patients were selected for the proposed study. The selected patients were given four questionnaires that were constructed based on transtheoretical model (TTM), and the patients were divided subsequently into five different groups (precontemplation, contemplation, preparation, action, and maintenance groups) based on their answers to the questionnaires. Then, each patient was given four appointments for their periodontal treatment spaced with a time gap of 10 days. The patients visit for each appointments scheduled to them was documented. The results obtained were assessed using TTM. RESULTS: Higher mean pro scores of decisional balance, self-efficacy, and process of change scores was recorded in maintenance group followed by action group, preparation group, contemplation group, and precontemplation group, respectively, whereas higher mean cons score was recorded in precontemplation group followed by contemplation group, preparation group, action group, and maintenance group, respectively. The difference scores of TTM constructs were statistically highly significant between all the five groups. Furthermore, the number of appointment attended in were significantly more than maintenance group followed by action group, preparation group, contemplation group, and precontemplation group. CONCLUSION: Within the limitations of this study, it can be concluded that transtheoretical model can be successfully applied to chronic periodontitis patients to assess their compliance to the suggested periodontal treatment.

A Radiographic Classification for Retrograde Peri-implantitis.

BACKGROUND: Retrograde peri-implantitis (RPI) is an inflammatory disease that affects the apical part of an osseointegrated implant, while the coronal portion of the implant sustains a normal bone-to-implant interface. It is a diagnostic and therapeutic dilemma for implantologists. There is lack of a standard classification system and a definite treatment algorithm for the same. This article aims to introduce a classification system for RPI based on the radiographic amount of bone loss around an implant apex. MATERIALS AND METHODS: A search of PubMed database was conducted with the keywords "retrograde peri-implantitis" and "implant periapical lesion." Preoperative intraoral periapical (IOPA) radiographs of implants with RPI in case reports/case series were compiled. A total of 54 lOPAs from 36 articles were compiled and were assessed. RESULTS: Three different classes were proposed. The amount of bone loss from the apex of the implant to the most coronal part of radiolucency was calculated as a percentage of the total implant length and classified into one of the three classes: Mild, moderate, and advanced. Treatment options and prognosis have been suggested for each class. CONCLUSION: The proposed classification may allow for an easy and reproducible radiographic assessment of the RPI lesion and may serve as a guideline to prognosis and treatment planning.

Titanium Corrosion: Implications For Dental Implants.

Titanium has been considered as one of the most biocompatible metals. Studies testing its corrosion resistance have proposed that the titanium oxide layer formed on the metal surface is lost under certain unavoidable conditions to which it is exposed in the oral environment. This questions its property of corrosion resistance in the oral cavity. Hence, there is a need to understand the mechanisms of corrosion, which can help in the long-term stability and function of implants. Here, we review the possible pathways of corrosion of titanium in the oral cavity, its implications and proposed methods of prevention of corrosion.

Immediate 3-dimensional ridge augmentation after extraction of periodontally hopeless tooth using chinblock graft.

BACKGROUND: The aim of the present study was to evaluate clinically and radiographically, the efficacy of immediate ridge augmentation to reconstruct the vertical and horizontal dimensions at extraction sites of periodontally hopeless tooth using an autogenous chin block graft. MATERIAL AND METHODS: A total of 11 patients (7 male & 4 female) with localized advanced bone loss around single rooted teeth having hopeless prognosis and indicated for extraction were selected for the study. The teeth were atraumatically extracted and deficient sites were augmented using autogenous chin block graft. Parameters like clinically soft tissue height - width and also radiographic ridge height -width were measured before and 6 months after augmentation. Obtained results were tabulated and analysed statistically. RESULTS: After 6 months of immediate ridge augmentation, the mean gain in radiographic vertical height and horizontal width was 7.64 + 1.47 mm (P = 0.005) and 5.28 + 0.46 mm (P = 0.007) respectively which was found to be statistically significant (P < 0.05). Mean change of width gain of 0.40mm and height loss of 0.40mm of soft tissue parameters, from the baseline till completion of the study at 6 months was observed. CONCLUSIONS: The present study showed predictable immediate ridge augmentation with autogenous chin block graft at periodontally compromised extraction site. It can provide adequate hard and soft tissue foundation for perfect 3-Dimensional prosthetic positioning of implant in severely deficient ridges. KEY WORDS: Immediate ridge augmentation, periondontally hopeless tooth, autogenous chin graft, dental implant.

Recent modifications of free gingival graft: A case series.

Free gingival grafts have been used in periodontal procedures to augment attached gingiva and cover denuded root surfaces. However, there are few limitations of the same such as esthetic mismatch, mal-alignment of muco-gingival junction formation and bulky appearance. Several modifications have recently been proposed to minimize some of the unfavorable aspects of free gingival grafts. Three cases presenting with Millers Class I/II gingival recession were treated by each different modifications. Satisfactory root coverage and better color match as a compared to free gingival graft was obtained in all the three cases. When indicated these modifications can be advantageous over conventional free gingival grafts in management of Millers Class I/II gingival recession.

Oxidized-low density lipoprotein in gingival crevicular fluid of patients with chronic periodontitis: a possible link to atherogenesis.

OBJECTIVE: To investigate a possible link between periodontitis and atherogenesis by examining the levels of anti-oxidized low density lipoprotien (ox LDL) and low density lipoprotien (LDL) in gingival crevicular fluid (GCF) and serum of healthy subjects and chronic periodontitis patients. METHODS: Sixty male subjects (35-55 years) were grouped into 30 healthy individuals and 30 subjects with chronic periodontitis. Serum and GCF samples were obtained from each subject and were assessed for anti-ox LDL and LDL levels. RESULTS: A significant difference (p < 0.001) was found between the anti-ox-LDL levels in GCF of healthy vs chronic periodontitis groups. Also the ratio of GCF anti-ox LDL to GCF LDL was significantly higher (p < 0.001) in chronic periodontitis patients as compared to the healthy group. CONCLUSIONS: A significant rise in ox LDL level in otherwise systemically healthy chronic periodontitis patients may put these subjects at an increased risk of developing atherosclerosis.