Clinical and histological evaluation of postextraction platelet-rich fibrin socket filling: a prospective randomized controlled study

Effect of Autologous Concentrated Growth Factor in Regenerative Dentistry: A Systematic Review and Meta-Analysis

INTRODUCTION

Concentrated growth factor (CGF), a novel autologous platelet concentrate, has gained substantial interest for its potential role in managing oral diseases. The objective of this study is to evaluate the effectiveness of CGF in regenerative dentistry.

METHODS

A systematic search was performed across MEDLINE, OVID, Scopus, Cochrane Library, Google Scholar, Web of Science, and Elsevier for publications between July 1, 2013, and July 1, 2023. Only randomized clinical trials were included. The quality of the methodology was assessed using the Cochrane Risk of Bias Tool. Data were analyzed using RevMan 5.4 software.

RESULTS

In 3 trials treating periodontal intrabony defects, CGF combined with bone grafts showed significant superiority over bone grafts alone (P < .00001), with a mean reduction of 1.41 mm in intrabony defect depth and a mean gain of 0.55 mm in clinical attachment level (P = 0.002). For gingival recession in 5 trials, CGF combined with coronally advanced flap (CAF) was more effective than CAF alone, resulting in a mean increase in keratinized tissue width of 0.41 mm and a mean increase in gingival thickness of 0.26 mm (P < 0.00001). However, CGF combined with CAF was less effective than connective tissue graft (CTG) combined with CAF, showing a mean difference in root coverage of -15.09% and a mean difference in gingival thickness of -0.50 mm (P < 0.0001). In alveolar ridge preservation, sinus elevation, guided bone regeneration, dental implant procedures, and postextraction healing, CGF gave better values in clinical practice.

CONCLUSIONS

CGF enhances regenerative surgery outcomes for periodontal intrabony defects. Combined with CAF, CGF improves therapeutic efficacy for gingival recession, although less so than CTG with CAF. CGF shows promise in various regenerative dentistry areas. However, the absence of meta-analysis and low-quality assessments in many studies necessitates further high-quality research.Knowledge Transfer Statement:The use of concentrated growth factors (CGFs) in regenerative dentistry, within the limitation of low-quality studies, shows promising benefits in treating periodontitis infrabony defects, gingival recession, guided bone regeneration, dental implant alveolar ridge preservation, sinus elevation, and third molar extraction. Future research should focus on high-quality studies and explore combining CGF with grafting materials to enhance therapeutic outcomes in oral surgery.

Greater bone regeneration required for implants following periodontal extraction: a retrospective cross-sectional study

BACKGROUND

We evaluated cone beam computed tomography images to compare the complexity of dental implant surgery after alveolar ridge preservation in damaged versus intact sockets resulting from severe periodontitis-related tooth extraction.

METHODS

In a retrospective analysis of 165 alveolar ridge preservation sites among 116 patients, we categorized 72 sockets as damaged and 93 as intact. Using cone beam computed tomography, we measured bone width at three vertical levels and compared bone regeneration needs for subsequent dental implant surgery between socket types.

RESULTS

Despite no difference in bone width between damaged and intact sockets, implant placement revealed differing regenerative needs. Mandibular teeth and non-drinkers required less regeneration. Damaged sockets exhibited 3.02 times higher regeneration requirements compared to intact ones.

CONCLUSIONS

The complexity of implant surgery following alveolar ridge preservation is influenced by alcohol consumption, tooth position, and periodontitis-related tooth extraction.

CLINICAL TRIAL REGISTRATION

The ClinicalTrials.gov Identifier: NCT05657223, 20/12/2022.

Development of Semi-Automated Image-Based Analysis Tool for CBCT Evaluation of Alveolar Ridge Changes After Tooth Extraction

Following tooth extraction, the bone structure is prone to atrophic changes. Alveolar ridge resorption can compromise subsequent implant treatment not only at the extraction site itself but also by affecting the bone support of adjacent teeth. Various techniques, including the use of bone graft materials or autologous blood concentrates for ridge or socket preservation, aim to counteract this process. The efficacy of such methods can be evaluated non-invasively through radiological analysis of the treated region. However, existing radiological evaluation methods often focus only on isolated areas of the extraction socket, limiting their accuracy in assessing overall bone regeneration. This study introduces a novel, non-invasive, and semi-automated image-based analysis method that enables a more comprehensive evaluation of bone preservation using CBCT data. Developed with the open-source software "Fiji" (v2.15.0; based on ImageJ), the approach assesses bone changes at multiple horizontal and vertical positions, creating a near three-dimensional representation of the resorptive process. By analyzing the entire region around the extraction socket rather than selected regions, this method provides a more precise and reproducible assessment of alveolar ridge preservation. Although the approach requires some processing time and focuses exclusively on radiological evaluation, it offers greater accuracy than conventional methods. Its standardized and objective nature makes it a valuable tool for clinical research, facilitating more reliable comparisons of different socket preservation strategies.

Introduction of a Semi-Quantitative Image-Based Analysis Tool for CBCT-Based Evaluation of Bone Regeneration in Tooth Extraction Sockets

After tooth extraction, resorptive changes in extraction sockets and the adjacent alveolar ridge can affect subsequent tooth replacement and implantation. Several surgical concepts, including the application of autologous blood concentrate platelet-rich fibrin (PRF), aim to reduce these changes. While PRF's wound-healing and pain-relieving effects are well-documented, its impact on bone regeneration is less clear due to varying PRF protocols and measurement methods for bone regeneration. This study aimed to develop a precise, easy-to-use non-invasive radiological evaluation method that examines the entire extraction socket to assess bone regeneration using CBCT data from clinical trials. The method, based on the freely available Image J-based software "Fiji", proved to be precise, reproducible, and transferable. As limitation remains the time requirement and its exclusive focus on radiological bone regeneration. Nevertheless, the method presented here is more precise than the ones currently described in the literature, as it evaluates the entire socket rather than partial areas. The application of the novel method to measure mineralized socket volume and radiological bone density of newly formed bone in a randomized, controlled clinical trial assessing solid PRF for socket preservation in premolar and molar sockets showed only slight, statistically non-significant trends toward better regeneration in the PRF group compared to natural healing.

Instructions for the use of L-PRF in different clinical indications

Autologous platelet concentrates (APCs) have demonstrated clear benefits across various clinical applications, including alveolar ridge preservation, guided tissue regeneration, guided bone regeneration, sinus floor elevation (both lateral window approach and transcrestal technique), endodontic surgery, the treatment of medication-related osteonecrosis of the jaw bones, and periodontal plastic surgery. To ensure an optimal clinical outcome, clinicians must adhere strictly to the protocol to prepare the APCs and, especially follow evidence-based surgical guidelines, often simple but crucial, to minimize the likelihood of errors. The majority of clinical trials reported on second-generation APCs [the leukocyte- and platelet-rich fibrin (L-PRF) family, including its modifications (A-PRF, A-PRF+, CGF, T-PRF, H-PRF, etc.)]. These second-generation APCs offer additional benefits compared to the first-generation APCs, making them the preferred choice for the development of clinical recommendations. These recommendations have been formulated through a meticulous examination of the available clinical data and the clinical experience of the authors of this paper.

Autologous platelet concentrates in alveolar ridge preservation: A systematic review with meta-analyses

In order to evaluate the therapeutic advantages of various autologous platelet concentrates (APC) as a single biomaterial during alveolar ridge preservation (ARP), a systematic review with meta-analyses was conducted. PubMed, EMBASE, Web of Science, and Scopus were screened for randomized controlled trials (RCTs) that were released prior to 2024. The selected papers compared an APC with either unassisted healing (blood clot) or another biomaterial during ARP (third molars were not included). The outcome parameters included alveolar bone dimension alterations, soft tissue healing, and post-op pain intensity. The search yielded 35 papers (33 studies), one applying platelet-rich plasma (PRP), six using plasma rich in growth factors (PRGF), and 28 using leukocyte- and platelet-rich fibrin (L-PRF). These studies showed a large heterogeneity (e.g., outcome parameters, timing, surgical approach, and inclusion criteria), which hindered drawing strong conclusions. In most studies, however, ARP with PRP, PRGF, and L-PRF alone produced faster soft tissue healing, less post-extraction pain, less alveolar ridge resorption, more socket bone fill, and a higher bone density when compared to unassisted (spontaneous) healing. The ultimate benefit appears to be significantly influenced by the surgical approach. Limited literature exists comparing APC with other biomaterials for ARP, resulting in inconclusive data. APC application for ARP is a promising strategy to improve soft and hard tissue healing and reduce post-extraction pain.

The ability of different forms of autogenous tooth graft to promote bone regeneration: a network meta-analysis

PURPOSE

Several forms of autogenous tooth graft have been presented. However, it is still unclear which form provides better bone formation and is the best to use clinically. This network meta-analysis aimed to thoroughly evaluate the available literature on the ability of different forms of the autogenous tooth graft to promote bone regeneration, in order to explore if any specific type or method of processing would result in better overall outcomes.

METHODS

MEDLINE/PubMed, Cochrane library, and Scopus databases were searched, to find randomized clinical trials, published up to November 29, 2023, which compared two forms of autogenous tooth graft or any form of this material with other bone grafts or with empty sockets and reported the percentage of bone formation in the grafted sites.

RESULTS

Of 1129 articles found, nine were included. The outcomes of this meta-analysis indicated that demineralized dentin, demineralized root with BMP-2 and undemineralized tooth all showed significantly higher bone formation, compared to xenograft; Mean difference (MD) = 23.25, 95% Confidence interval (CI) = 7.42 to 39.08, MD = 17.09, 95% CI = 4.03 to 30.15, and MD = 12.40, 95% CI = 5.64 to 19.16, respectively. Following the GRADE system, the level of evidence was judged to be low/very low.

CONCLUSION

Choosing the undemineralized tooth could be a better option than other forms of this material, considering the complexity, time, and cost of the other forms of autogenous tooth graft. Nevertheless, future investigations with more direct comparisons are highly needed, considering the small number of included studies and the low level of evidence obtained from this meta-analysis.

A Comparison of the Dimensional Characteristics and Plasma Parameters of Different Centrifuges Used for the Preparation of Autologous Platelet Concentrates: A Randomized Correlational Study

OBJECTIVE

The objective of this study was to evaluate autologous platelet-rich fibrin (PRF) membrane weights and measurements after production by different centrifuges. Moreover, the values obtained with blood cellular components were correlated.

METHODS

Twelve systemically healthy participants underwent dental implant surgery associated with PRF membranes as the graft biomaterial at the implant site. Prior to the surgical procedure, the chosen participants underwent blood count and coagulogram tests and presented on the surgical day. Nine tubes containing 10 mL of venous blood were collected from each individual. The tubes were randomly distributed and positioned in three different centrifuges: (C1) the Intra-lock L-PRF Process, (C2) the Kasvi Digital, and (C3) the PRF Montserrat. PRF membrane processing was carried out as described by each manufacturer. After the processing steps, the prepared wet PRFs (initial) were placed in the container (box) designated by the manufacturer for the obtention of PRF membranes. The weights and measurements of the "wet" PRFs (initial) and membranes (final) were obtained using a precision scale and digital caliper in an aseptic environment. The data were compared, and the statistical differences were analyzed using the Friedman test and the Dunn post hoc test; Pearson correlation tests were performed between macroscopic data and data from serum tests; statistical significance was set at 5% (p < 0.05).

RESULTS

108 blood collection tubes were collected. The average harvest time for each tube individually was 21.5 ± 9.9 s. The average time for blood collection (nine tubes) from each of the 12 individuals was 193.1 ± 72.4 s (p = 0.728). The average values were very similar between the centrifuges, both for the measurements and weights of the "plugs" as well as for the linear measurements (p > 0.05). Regarding the wet weights and the linear averages of the PRF membranes, it was observed that the wet PRF weights varied from 0.22 to 0.25 mg and the linear measurements from 24.1 to 26.7 mm, with no statistical differences between centrifuges (p > 0.05). The data presented by centrifuges C1 and C2 were more homogeneous, delivering a value of less than 25% variability compared to the C3 centrifuge, which achieved values greater than 33%.

CONCLUSIONS

The proposed macroscopic dimensional evaluation found no differences between the autologous platelet concentrates obtained by different centrifuges, and no correlation was found between these PRFs and the patients' blood counts.

Does Varying Platelet-Rich Fibrin Centri̇fugati̇on Protocols Enhance New Bone Formati̇on in Extracti̇on Site?

BACKGROUND

Finding a protocol that could prevent bone resorption and be implemented in clinical practice would be crucial in providing sufficient bone to replace missing teeth with implants.

PURPOSE

The study aimed to determine the effectiveness of different centrifugation platelet-rich fibrin (PRF) protocols in new bone formation and bone regenerative markers.

STUDY DESIGN, SETTING AND SAMPLE

This randomized clinical trial was conducted at Izmir Katip Çelebi Research Hospital, a population-based facility in Izmir, Turkey. Study subjects were composed of patients who required extraction of anterior teeth. Exclusion criteria included periodontal disease, resorption of alveolar bone, defects, smoking, alcoholism, and systemic diseases.

INDEPENDENT VARIABLE

The independent variable was the PRF protocol. The subjects were randomly assigned to one of three groups: leukocyte platelet-rich fibrin (L-PRF), advanced platelet-rich fibrin (A-PRF) and control groups (healing naturally).

MAIN OUTCOME VARIABLE

The primary outcome of interest was the percentage of new bone formation, determined by analyzing the staining intensity in histomorphometric assessments of bone samples collected 8 weeks after extraction. The secondary outcomes were regenerative effects measured by the immunohistochemical expression of markers such as osteocalcin, alkaline phosphatase, and proliferating cell nuclear antigen. Potential benefits were evaluated by clinical observations of pain, swelling, membrane visibility and healing.

COVARIATES

The covariates were age, sex and health conditions.

ANALYSES

Histologic comparative staining intensities and biomarkers expression between groups were evaluated by one way analysis of variance. A difference of P < .05 was considered statistically significant.

RESULTS

The study included 57 subjects, with a mean age of 45 years (±5.6); 30 were male (53%) and 27 female (47%). The control group had a mean new bone formation of 32.68% (±2.5), the A-PRF group 61.37% (±3.0), and the L-PRF group 70.74% (±3.5) (P < .001). The A-PRF group showed significantly higher osteocalcin expression than the control group (P = .013). Alkaline phosphatase and proliferating cell nuclear antigen expression scores for PRF groups were significantly higher than the control group's (P = .001). Both groups demonstrated significantly lower pain scores, reduced gingival swelling, better membrane visibility, and healing compared to the control group.

CONCLUSION AND RELEVANCE

PRF enhanced bone formation rates, with L-PRF showing the most significant effect.

Guided Bone Regeneration: CGF and PRF Combined With Various Types of Scaffolds-A Systematic Review

Objective: Bone regeneration plays a pivotal role in modern oral surgery, particularly in facilitating successful implant-prosthetic rehabilitation. This systematic review explores the regenerative potential of growth factors, such as platelet-rich fibrin (PRF) and concentrated growth factors (CGFs), when combined with various types of scaffolds in bone augmentation procedures, including guided bone regeneration, split crest, sinus lift (SL), and alveolar ridge preservation. Method: A comprehensive search strategy yielded 18 relevant studies, which were analyzed for bone formation and stabilization outcomes. Results: Results indicate that PRF enhances bone regeneration and stabilization in SL and ridge augmentation procedures, while CGFs facilitate surgical techniques and augment bone. However, some studies did not report significant differences. Growth factors also demonstrate benefits in wound healing, reducing bone resorption, and enhancing socket preservation. Conclusion: Despite valuable insights, further research is needed to comprehensively understand the characteristics of growth factors in various surgical interventions, ensuring informed decision-making in bone regeneration surgery.

A systematic review and meta-analysis on the use of regenerative graft materials for socket preservation in randomized clinical trials

OBJECTIVE

To evaluate if regenerative materials with/without scaffold deployed in dental socket preservation led to reduced radiographic height and width bone resorption.

STUDY DESIGN

English-written human studies from January 2010 to December 2023 were selected from PubMed, EMBASE, MEDLINE, Cochrane CENTRAL, Google Scholar and manually searched journals. Six meta-analyses were conducted, addressing treatments with all blood-derived growth factor preparations as well as L-platelet-rich fibrin (L-PRF) separately, and recombinant human BMP-2 (rhBMP-2). An unpaired t-test on L-PRF and rhBMP-2 determined the clinically best preservation treatment. Cochrane risk of bias in all studies was analyzed.

RESULTS

Twenty-nine articles (1068 participants) were included. Meta-analyses on blood-derived preparations demonstrated nonsignificant alveolar width, but significant (p = .001) height preservation. L-PRF vs. natural healing demonstrated nonsignificant changes in both dimensions. RhBMP-2 caused highly significant reduced horizontal (p = .01) and vertical (p < .0008) bone resorptions. When comparing mean resorption rates, significant benefits of rhBMP-2 over L-PRF were observed for width but not height preservation (p < .0001 and p = .057, respectively). Six studies recorded low, 8 moderate, and 15 high net risks.

CONCLUSIONS

Regenerative materials appear beneficial for radiographic bone width and height preservation after tooth extraction. Although rhBMP-2 performed better in alveolar width preservation, L-PRF can be an autologous and cost-effective alternative.

Comparison of Histological, Clinical, and Radiographic Outcomes of Postextraction Ridge Preservation by Allogenic Bone Grafting With and Without Injectable Platelet-Rich Fibrin: A Double-Blinded Randomized Controlled Clinical Trial

Objectives: This randomized controlled clinical trial compared the histological, clinical, and radiographic outcomes of postextraction ridge preservation by allogenic bone grafting with and without injectable platelet-rich fibrin (I-PRF). Materials and Methods: Twenty single-rooted maxillary and mandibular teeth to be extracted and replaced by dental implants were randomly divided into two groups (n = 10). Cone-beam computed tomography (CBCT) scans were obtained preoperatively to assess bone dimensions and ridge width. The teeth were then extracted, and tooth socket preservation was performed with allograft and collagen type 1 in the control group and allograft, collagen type 1, and I-PRF in the intervention group. CBCT scans were obtained again 3 months after the first stage of surgery, and the second stage of surgery was performed for implant placement, ridge width measurement, and obtaining a biopsy sample. Radiographic bone width, clinical bone width, and radiographic bone height were measured. A histomorphometric method was applied to quantify residual graft material, new bone formation, and nonmineralized tissues. The data were analyzed with Student's t-test and Mann-Whitney U test (α = 0.05). Results: The intervention group showed a significantly smaller reduction in radiographic bone width (P=0.038) and clinical bone width (P=0.033), reduction in radiographic bone height (P=0.213) was not significant. A significantly lower percentage of residual graft particles (P=0.021) and a significantly higher mean percentage of newly formed bone (P=0.038) than the control group. However, the difference in the percentage of nonmineralized tissue (P=0.208) was not significant. Conclusion: Despite the optimal outcome of ridge preservation in both groups, the application of allograft plus I-PRF yielded superior histological, clinical, and radiographic results compared with allograft alone, and this difference was significant in most variables.

"Comparison of activated Platelet Rich Fibrin and Platelet Rich Fibrin in osseous regeneration of freshly extracted socket- A double blinded randomized clinical study"

INTRODUCTION

Dental extraction is a common oral surgery procedure, but it can lead to unpredictable changes in alveolar bone structure, which can complicate future rehabilitation with prostheses. Socket preservation aims to reduce bone and soft tissue loss after extraction and involves various techniques using different materials. Autogenous bone is considered the gold standard for grafts, while autologous platelet concentrates like platelet-rich fibrin (PRF) have been used for tissue healing. This study aims to radiographically assess the bone remodeling of freshly extracted socket filled with Activated Platelet Rich Fibrin (APRF) and PRF.

MATERIALS AND METHODS

A randomized controlled study was conducted on 60 patients undergoing tooth extraction as atraumatic as possible. Patients were divided into two groups: one receiving APRF with 10% Calcium Chloride as activating agent and the other PRF. Radiographic assessments were done using Kelley et al. scoring criteria at various time intervals, and statistical analyses were performed to evaluate the results.

RESULTS

In this study we found increased bone density in extracted socket filled with APRF at any given time interval compared to PRF which is statistically significant. The maxilla demonstrated better bone formation compared to the mandible. Gender, age, and site also influenced bone formation, with females showing differences in lamina dura and overall density.

DISCUSSION

PRF is rich in growth factors, promoting osteoblast formation and angiogenesis. Activation with calcium chloride accelerates clot formation and the release of growth factors. This study's radiographic data suggests that APRF may be more effective than PRF in promoting socket preservation and bone formation.

Comprehensive analysis of bone tissue in extraction sockets of third molars after leukocyte and platelet rich fibrin and photobiomodulation applications

OBJECTIVES

The aim of this study was to compare leukocyte and platelet-rich fibrin (L-PRF) and photobiomodulation (PBM) applications, which have been repeatedly reported to be superior to control groups, in terms of pain, soft tissue and bone healing in tooth extraction sockets.

MATERIALS AND METHODS

This double-blind, randomized clinical study was completed with 34 patients, who had an indication for extraction of their bilaterally impacted teeth. The right and left teeth of the patients were randomly divided into L-PRF and PBM groups. L-PRF group was treated with the blood product centrifuged for 12 min at 2700 rpm, and the PBM group was treated with a diode laser at different points for 60 s with a wavelength of 940 nm in repeated sessions. Postoperative pain was evaluated using Visual Analogue Scale (VAS), soft tissue healing with Landry Index (LI), tissue healing in the distal region of mandibular second molar by probing depth measurement, and bone healing via panoramic x-ray using the Image J program.

RESULTS

No statistically significant difference was found for any variable compared between the groups.

CONCLUSION

L-PRF and PBM applications provide similar support in the healing of extraction sockets. Nevertheless, the advantages and disadvantages of both methods determine their usage areas.

CLINICAL RELEVANCE

While L-PRF is advantageous in the early healing of extraction sockets, PBM may be preferred in terms of bone trabeculation in the long term.

Efficacy of Platelet-Rich Fibrin in Preserving Alveolar Ridge Volume and Reducing Postoperative Pain in Site Preservation of Post-Extracted Sockets

Background and Objectives: In socket preservation, the goal is to minimize bone resorption after tooth extraction to maintain the volume and contour of the alveolar ridge. The use of PRF in post extraction sites may reduce ridge resorption by encouraging the growth of new bone and acting as a scaffold for tissue. In addition, PRF may enhance healing and minimize postoperative pain. The aim of this study was to evaluate the effectiveness of platelet-rich fibrin (PRF) in maintaining the ridges' dimensions at the extraction site, in the maxilla and mandible, as well as its impact on post-extraction discomfort. Methods: The study was conducted on 60 patients presenting for extraction of posterior teeth and was randomly divided into three groups: group I PRF (n = 20), group II PRF + collagen (n = 20), and group III control (n = 20). Sockets were filled with PRF (group I) and PRF + collagen (group II). At baseline and follow-up after 3 months, CBCT was used to assess the bone dimensions. The postoperative pain evaluations were performed at 24 h, 3 days, and 7 days after the tooth extraction. The pain rate was evaluated using a numerical rating scale from the British Pain Society. Results: The study examined the effects of platelet-rich fibrin (PRF) and PRF combined with collagen on the height and width of the ridges, as well as the pain experienced by the patients following alveolar ridge preservation surgery. ANOVA and t-tests were used to evaluate and compare the ridge dimensions. Comparing the results to the control group, there were no significant differences in the height or width of the ridges. However, both the PRF and PRF + Collaplug® treatments effectively reduced the short-term postoperative pain. Conclusions: The study findings suggest that platelet-rich fibrin (PRF) and PRF combined with collagen do not exert significant effects on ridge width and height compared to the standard treatment following alveolar ridge preservation. However, it is noteworthy that both the PRF and PRF + collagen treatments demonstrated efficacy in reducing postoperative pain in the short term, offering a potential advantage over standard treatment protocols.

Healing of Extraction Sites after Alveolar Ridge Preservation Using Advanced Platelet-Rich Fibrin: A Retrospective Study

BACKGROUND

Over time, numerous surgical procedures and biomaterials have been proposed for the reconstruction of post-extraction bone defects, each with their advantages and disadvantages. The main objective of this study was to evaluate dimensional changes in the alveolar bone 3 months after tooth extraction, before implant planning, comparing alveolar ridge preservation (ARP) with spontaneous healing.

METHODS

A total of 84 patients with non-restorable molars were included in the study. Forty-two patients received ARP with advanced platelet-rich fibrin (A-PRF) and spontaneous healing was evaluated in these patients. Cone beam computed tomography (CBCT) analysis performed before and after surgical intervention was used to determine the changes in vertical and horizontal bone dimensions produced after tooth extraction.

RESULTS

CBCT measurements showed reduction in both vertical and horizontal alveolar bone size in both groups. For the study group, the alveolar parameters (height, width) were higher compared to the control group. The percentage variations between dimensional differences from the two groups were 38.58% for height, and for width were 36.88% at 0 mm, 35.56% at 3 mm, 36.61% at 5 mm, and 38.73% at 7 mm. The differences were statistically significant (p ˂ 0.0005).

CONCLUSIONS

The results obtained after ARP with A-PRF showed a reduced loss of bone volume compared to spontaneous healing.

Evaluation of Alveolar Ridge Dimensions by Socket Preservation Therapy Using a Bone Graft and Platelet-Rich Fibrin: A Randomized Controlled Trial

BACKGROUND

Following the loss of a tooth, the new edentulous area of the ridge will undergo several adaptive modifications due to changes in function within and surrounding the socket. This bone resorption explains the need for socket preservation techniques in areas of esthetic concerns and functional demands. Demineralized freeze-dried bone allograft (DFDBA) possesses greater osteoinductive potential due to the exposure of bone morphogenetic protein (BMP-3​​​​​​)​and collagen fibrils and can be used efficiently in socket preservation techniques. DFDBA yields better results when combined with an autologous platelet concentrate, such as platelet-rich fibrin. Therefore, we formulated this randomized controlled clinical trial to assess the clinical and radiovisiographical outcomes of platelet-rich fibrin (PRF) and DFDBAs for extraction socket preservation in humans at different time intervals.

MATERIALS AND METHODS

This was a randomized controlled trial with 100 people as study subjects, and they were randomly divided into two groups: the test group (DFDBA and PRF placed in the extraction socket) and the control group (natural healing of the extraction socket). Clinical and radiographic evaluation using radiovisiography (RVG) was done at baseline, three-month, and six-month intervals. Cone-beam computed tomography (CBCT) was used at six months to determine the bone density in the test and control groups.

RESULTS

When compared from baseline to six months, the percentage change in clinical and RVG measurements for the test group was 15.96% (11.9064 mm) and 16.77% (12.1840 mm), respectively, whereas for the control group, it was 46.09% (14.0396 mm) and 47.61% (14.5716 mm), thus indicating lesser bone resorption in the test group as opposed to the control group. CBCT values also showed greater bone density for the test group (682.3120 HU) than the control group (503.8336 HU).

CONCLUSION

This study demonstrates the advantages of DFDBA bone graft with PRF compared to natural healing in achieving socket preservation by maintaining the marginal and buccolingual bone levels.

Autologous Tooth Granulometry and Specific Surface Area with Three Grinding Methods: An In Vitro Study

A postextraction socket becomes a clinical challenge due to the fact that a series of changes associated with bone remodelling and resorption of the socket that occur after extraction, which limits the aesthetic and functional prognosis of implant-supported rehabilitations. It has been studied that the use of the autologous tooth-derived graft (ATDG) has regenerative properties and could therefore be useful for solving this type of problem. There is no consensus in the scientific literature on a standardized protocol for the use of the autologous tooth. Therefore, the aim of the present study was to evaluate the most relevant parameters to achieve the best properties of ground ATDG using three methods, namely Gouge forceps, electric grinder, and manual, that made up the study group (SG) and compared with the control group (CG) consisting of Bio-Oss®. The sample obtained by the electric grinder had the highest value of specific surface area (2.4025 ± 0.0218 m2/g), while the particle size as average diameter (751.9 µm) was the lowest and most homogeneous of the three groups. Therefore, the electric grinder allowed for obtaining ATDG with more regenerative properties due to its specific surface-area value and particle size in accordance with the xenograft with the greatest bibliographical support (Bio-Oss®). The higher specific surface increases the reaction with the physiological media, producing faster biological mechanisms.

Evaluation of the effects of platelet-rich fibrin and diode laser on gingival blood perfusion and early bone healing of the extraction socket: a randomized controlled clinical trial

Evaluation and comparison of the effect of platelet-rich fibrin (PRF), diode laser, and combination of PRF and diode laser on gingival blood perfusion and early bone formation of the extraction socket. Forty maxillary premolar sockets were randomized to four groups: control group, PRF group, diode laser group, and PRF + diode laser group. Gingival blood perfusion was measured at preoperative and postoperative 1, 3, 7, and 30 days. Fractal dimension analysis was performed immediately after the procedure and in the postoperative first month. Gingival perfusions significantly increased during 1 week compared to baseline for all groups with a mean of -4.43 ± 3.20, -5.99 ± 3.68, -5.45 ± 3.01, and -4.78 ± 2.82 respectively, and were at baseline 1 month later. There were no statistically significant differences between the groups at any time point. Although the increase of fractal dimension was higher in the PRF or diode laser group than in the control group with a mean of 0.085 ± 0.05, 0.100 ± 0.04, and 0.072 ± 0.04 respectively, no statistically significant differences were detected. Fractal dimension was significantly greater in PRF + diode laser group than in the control group with a mean of 0.138 ± 0.05 (p = 0.04). PRF, diode laser, and PRF + diode laser did not significantly affect the gingival perfusion, and the combined application of PRF and diode laser had positive effects on early bone regeneration in the extraction socket. PRF, diode laser, and PRF + diode laser provide better tissue healing of the extraction socket.

Prevalence of peri-implantitis after alveolar ridge preservation at periodontitis and nonperiodontitis extraction sites: A retrospective cohort study

INTRODUCTION

Periodontitis is the main indication for dental extraction and often leads to peri-implantitis (PI). Alveolar ridge preservation (ARP) is an effective means of preserving ridge dimensions after extraction. However, whether PI prevalence is lower after ARP for extraction after periodontitis remains unclear. This study investigated PI after ARP in patients with periodontitis.

MATERIALS AND METHODS

This study explored the 138 dental implants of 113 patients. The reasons for extraction were categorized as periodontitis or nonperiodontitis. All implants were placed at sites treated using ARP. PI was diagnosed on the basis of radiographic bone loss of ≥3 mm, as determined through comparison of standardized bitewing radiographs obtained immediately after insertion with those obtained after at least 6 months. Chi-square and two-sample t testing and generalized estimating equations (GEE) logistic regression model were employed to identify risk factors for PI. Statistical significance was indicated by p < 0.05.

RESULTS

The overall PI prevalence was 24.6% (n = 34). The GEE univariate logistic regression demonstrated that implant sites and implant types were significantly associated with PI (premolar vs. molar: crude odds ratios [OR] = 5.27, 95% confidence intervals [CI] = 2.15-12.87, p = 0.0003; bone level vs. tissue level: crude OR = 5.08, 95% CI = 2.10-12.24; p = 0.003, respectively). After adjustment for confounding factors, the risks of PI were significantly associated with implant sites (premolar vs. molar: adjusted OR [AOR] = 4.62, 95% CI = 1.74-12.24; p = 0.002) and implant types (bone level vs. tissue level: AOR = 6.46, 95% CI = 1.67-25.02; p = 0.007). The reason for dental extraction-that is, periodontitis or nonperiodontitis-was not significantly associated with PI.

CONCLUSION

ARP reduces the incidence of periodontitis-related PI at extraction sites. To address the limitations of our study, consistent and prospective randomized controlled trials are warranted.

Effect of thermal manipulation on the biological and mechanical characteristics of horizontal platelet rich fibrin membranes

BACKGROUD

Regardless of application scenarios, proper mechanical characteristics and degradation properties are prerequisites for horizontal platelet rich fibrin (H-PRF) to manifest its ability. Among the methods used to modify PRF, thermal manipulation is promising as it is easy to handle without adding extra additives. Yet there is no consensus on optimal temperature treatment. This study aimed to investigate the effects of heating on the biological and mechanical characteristics of H-PRF and explore the optimum heating temperature for H-PRF thermal treatment.

METHODS

We employed a series of temperature gradients, room temperature, 50℃, 75℃, 90℃, 105℃. The microstructure and the mechanical properties were recorded by Scanning Electron Microscope (SEM) and tensile strength tests respectively. The degradation rate of H-PRF membranes was examined by digestion assay with plasmin and trypsin. The viability of cells within H-PRF membranes and the proliferation of osteoblasts cultured with extracts from different H-PRF groups was evaluated using CCK-8 assays.

RESULTS

Compared with the nonheated group, overheated manipulation beyond 90℃ can significantly prolong the degradation properties for up to 3 to 4 weeks and enhance the mass stress of H-PRF membranes. A high-temperature treatment of 105℃ accompanied by the cell activity beneath H-PRF reduced more than half, and thus, the biological effect on human osteoblasts (hFOBs) also reduced dramatically.

CONCLUSIONS

High thermal manipulation can prolong the degradation properties and enhance the mechanical properties of PRF membranes accompanied by the loss of biological effect.

Imaging Evaluation of Platelet-Rich Fibrin in Post-Exodontic Bone Regeneration: A Systematic Review

Tooth extraction is the most common procedure in dental practice. However, in the long term, it may cause alveolar ridge atrophy. This systematic review aimed to evaluate the role of platelet-rich fibrin (PRF) in post-exodontic alveolar ridge preservation in terms of its effectiveness in the regeneration of bone tissue as assessed by imaging and its efficacy compared to physiological bone healing. The study is presented in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. This systematic review was conducted using electronic databases such as PubMed, Scopus, Web of Science, and Science Direct. The gray literature search was conducted in the New York Academy of Medicine Grey Literature Report. All the studies in this systematic review were randomized controlled trials (RCTs). The risk of bias was performed according to the Cochrane Handbook for Systematic Reviews of Interventions 6.2 (RevMan 6.2). Considering the inclusion and exclusion criteria, we included 17 randomized clinical trials published up to 2022 investigating the efficacy of PRF in post-exodontic bone regeneration. Based on the results of clinical studies, it can be stated that despite not being statistically significant, PRF promotes neoformation and prevents bone loss between three and four months post-extraction.

Alveolar Ridge Preservation with Autologous Platelet-Rich Fibrin (PRF): Case Reports and the Rationale

In dental implantology, alveolar ridge preservation (ARP) has emerged as a standard technique to address dimensional changes that affect alveolar ridge morphology following tooth loss. Various alternative graft materials, including xenografts, alloplasts, and allografts, have been effectively employed in fresh extraction sites for ARP. Current evidence suggests that these materials primarily serve as bio-scaffolds, which are slowly incorporated, thus necessitating a waiting period of at least 4-6 months before implant placement. Consequently, the ARP technique extends the overall duration of implant treatment by several months. Recently, the incorporation of a form of autologous platelet concentrate, known as platelet-rich fibrin (PRF), has been advocated in conjunction with ARP as a method of bioenhancement of soft- and hard-tissue healing and regeneration. PRF contains platelet-derived growth factors, hormones, and bioactive components like cytokines that have demonstrated the ability to stimulate angiogenesis and tissue regeneration throughout all phases of wound healing. Additionally, the concentration of leukocytes present in the PRF matrix plays a vital role in tissue healing and regeneration as part of the osteoimmune response. The reported advantages of incorporating autogenous PRF platelet concentrates during ARP encompass reduced healing time, improved angiogenesis and bone regeneration, socket sealing through the fibrin matrix, antibacterial properties, and decreased post-extraction pain and infection risk. Therefore, the objective of this paper is to review the existing evidence regarding the application of PRF in alveolar ridge preservation (ARP) following tooth extraction. Two clinical case studies are presented, wherein ARP was enhanced with PRF, followed by implant placement within a relatively short period of 8 weeks. These cases serve as further proof of concept for supporting the adjuvant use of PRF to enhance healing and accelerate implant placement after ARP.

Do autologous platelet concentrates (APCs) have a role in intra-oral bone regeneration? A critical review of clinical guidelines on decision-making process

In the past decades, personalized regenerative medicine has gained increased attention. Autologous platelet concentrates (APCs) such as PRP, PRGF, and L-PRF, all serving as a source of a large variety of cells and growth factors that participate in hard and soft tissue healing and regeneration, could play a significant role in regenerative periodontal procedures. This narrative review evaluated the relative impact of APCs in alveolar ridge preservation, sinus floor augmentation, and the regeneration of bony craters around teeth, both as a single substitute or in combination with a xenograft. L-PRF has a significant beneficial effect on alveolar ridge preservation (bone quality). The data for PRGF are less convincing, and PRP is controversial. L-PRF can successfully be used as a single substitute during transcrestal (≥3.5 mm bone gain) as well as 1-stage lateral window sinus floor elevation (>5 mm bone gain). For PRGF and especially PRP the data are very scarce. In the treatment of bony craters around teeth, during open flap debridement, L-PRF as a single substitute showed significant adjunctive benefits (e.g., >PPD reduction, >CAL gain, >crater depth reduction). The data for PRP and PRGF were non-conclusive. Adding PRP or L-PRF to a xenograft during OFD resulted in additional improvements (>PPD reduction, >CAL gain, >bone fill), for PRGF no data were found. Autologous platelet concentrates demonstrated to enhance bone and soft tissue healing in periodontal regenerative procedures. The data for L-PRF were most convincing. L-PRF also has the advantage of a greater simplicity of production, and its 100% autologous character.

Immediate implant and socket preservation using sticky bone and leukocyte-platelet-rich fibrin in the anterior maxilla: A 3-year case report

INTRODUCTION

Immediate implant in the esthetic area is a challenging procedure. Chronic infection often contributes to extensive bone loss and acute infection often precludes a safe, clean surgery. However, it is quite common to come across failing teeth in the esthetic area, where the patient often demands a faster rehabilitation.

CASE PRESENTATION

In this clinical case, a fractured upper central incisor was replaced by an immediate implant, and the perimetrical area was filled with heterologous bone blended with patient-derived leukocyte- and platelet-rich fibrin (L-PRF) in the form of sticky bone. A Maryland bridge was bonded to the adjacent teeth with the intent to guarantee minimum esthetic to the patient. After 5 months, the implant was connected to a definitive abutment and crown. The facial and interdental soft tissue was maintained with appreciable success after 2 years. The pre-treatment and 2-year- post-treatment computed tomography scans revealed marginal bone preservation.

CONCLUSION

The use of sticky bone and L-PRF in immediate implant sites helps prevent hard and soft-tissue collapse and may favor faster and sounder healing.

KEY POINTS

Why is this case new information? It provides support to the efficacy of immediate implant placement with simultaneous use of L-PRF. What are the keys to successful management of this case? Having L-PRF supporting wound healing. What are the primary limitations to success in this case? Having sufficient bone apical to the existing socket and at adjacent teeth.

A Comparative Evaluation of Iliac Crest Cortical-Cancellous Bone Blocks Graft With and Without Concentrated Growth Factors (CGFs) in Secondary Alveolar Bone Grafting: A Retrospective Study

BACKGROUND

The purpose of this study was to investigate the clinical effect and bone resorption of iliac crest cortical-cancellous bone block grafts combined with concentrated growth factor (CGF) compared with iliac crest cortical-cancellous bone block grafts only in secondary alveolar bone grafting.

MATERIALS AND METHODS

Eighty-six patients (43 in the CGF group and 43 in the non-CGF group) with unilateral alveolar clefts were examined. Patients (17 in the CGF group and 17 in the non-CGF group) were randomly chosen for radiologic evaluation. Quantitative evaluation of the bone resorption rate was made with cone-beam computed tomography and Mimics 19.0 software at 1 week and 12 months after surgery.

RESULTS

The success rate of bone grafting was 95.3% and 79.1% in the CGF and non-CGF groups, respectively ( P =0.025). The mean bone resorption rate at 12 months postoperatively was 35.66±15.80% and 41.39±19.57% in the CGF and non-CGF groups, respectively ( P =0.355). The bone resorption patterns of the 2 groups were similar on the labial, alveolar process, and palatal sides, and there was no obvious bone resorption on the labial side in either group. Nasal side bone resorption in the CGF group was significantly less than that in the non-CGF group ( P =0.047).

CONCLUSIONS

Cortical-cancellous bone block grafts reduce labial bone resorption, while CGF reduces nasal bone resorption and improves the success rate. The combination of bone block and CGF in secondary alveolar bone grafting is worthy of further clinical application.

Current Progress of Platelet-Rich Derivatives in Cartilage and Joint Repairs

In recent years, several types of platelet concentrates have been investigated and applied in many fields, particularly in the musculoskeletal system. Platelet-rich fibrin (PRF) is an autologous biomaterial, a second-generation platelet concentrate containing platelets and growth factors in the form of fibrin membranes prepared from the blood of patients without additives. During tissue regeneration, platelet concentrates contain a higher percentage of leukocytes and a flexible fibrin net as a scaffold to improve cell migration in angiogenic, osteogenic, and antibacterial capacities during tissue regeneration. PRF enables the release of molecules over a longer period, which promotes tissue healing and regeneration. The potential of PRF to simulate the physiology and immunology of wound healing is also due to the high concentrations of released growth factors and anti-inflammatory cytokines that stimulate vessel formation, cell proliferation, and differentiation. These products have been used safely in clinical applications because of their autologous origin and minimally invasive nature. We focused on a narrative review of PRF therapy and its effects on musculoskeletal, oral, and maxillofacial surgeries and dermatology. We explored the components leading to the biological activity and the published preclinical and clinical research that supports its application in musculoskeletal therapy. The research generally supports the use of PRF as an adjuvant for various chronic muscle, cartilage, and tendon injuries. Further clinical trials are needed to prove the benefits of utilizing the potential of PRF.

Effect of the use of platelet concentrates on new bone formation in alveolar ridge preservation: a systematic review, meta-analysis, and trial sequential analysis

OBJECTIVES

To investigate the histomorphometric changes occurring in alveolar ridge preservation (ARP) based on the use of different plasma concentrates (PCs) in randomized clinical trials (RCT). There is controversy whether the placement of PCs in ARP is effective in the formation of new bone.

MATERIALS AND METHODS

A systematic review search was conducted in PubMed, Scopus, Web of Science, and Cochrane Database to answer the PICO question: In patients undergoing tooth extraction followed by ARP, do PCs alone in the post-extraction socket in comparison with spontaneous healing improve new vital bone formation percentage in histomorphometric analysis after more than 10 weeks? The risk of bias was assessed and a meta-analysis was conducted.

RESULTS

Of 3809 results, 8 studies were considered suitable for inclusion. A total of 255 teeth were extracted in 250 patients. Regarding the PCs used, ARP was performed with platelet- and leukocyte-rich fibrin (L-PRF) in 120 sockets, and with pure platelet-rich plasma (P-PRP) in 31 sockets and 104 sockets were controlled. PCs improved new bone formation in ARP with respect to the spontaneous healing group (SMD = 1.77, 95%C.I. = 1.47-2.06, p-value < 000.1). There were no differences between the different PCs (L-PRF and P-PRP).

CONCLUSION

The results of this meta-analysis support the efficacy of the use of PCs in new bone formation in ARP. With respect to the different types of PCs studied, no differences were observed.

CLINICAL RELEVANCE

When planning implant surgery after tooth extraction, treatment with PCs should be considered for ARP. Any PC increases new bone formation compared to spontaneous healing.

Alveolar ridge preservation: Complications and cost-effectiveness

Alveolar ridge preservation is routinely indicated in clinical practice with the purpose of attenuating postextraction ridge atrophy. Over the past two decades numerous clinical studies and reviews on this topic have populated the literature. In recent years the focus has primarily been on analyzing efficacy outcomes pertaining to postextraction dimensional changes, whereas other relevant facets of alveolar ridge preservation therapy have remained unexplored. With this premise, we carried out a comprehensive evidence-based assessment of the complications associated with different modalities of alveolar ridge preservation and modeled the cost-effectiveness of different therapeutic modalities as a function of changes in ridge width and height. We conclude that, among allogeneic and xenogeneic bone graft materials, increased expenditure does not translate into increased effectiveness of alveolar ridge preservation therapy. On the other hand, a significant association between expenditure on a barrier membrane and reduced horizontal and vertical ridge resorption was observed, though only to a certain degree, beyond which the return on investment was significantly diminished.

Platelet-rich fibrin vs. buccal advancement flap for closure of oroantral communications: a prospective clinical study

OBJECTIVES

The primary aim was to evaluate the success of the defect closure (tight or open) of oroantral communications (OAC) after treatment with platelet-rich fibrin (PRF) clots or a buccal advancement flap (BAF). Secondary outcome measurements were the evaluation of the wound healing, the displacement of the mucogingival border (MGB), and the pain level.

MATERIAL AND METHODS

Fifty eligible patients with an OAC defect larger than 3 mm were randomly assigned to either PRF (test group, n = 25) or BAF (control group, n = 25) for defect closure. In a prospective follow-up program of 21 days, the defect closure healing process, the wound healing course using Landry's wound healing index (score: 0-5), the displacement of the MGB, and the postoperative pain score were evaluated.

RESULTS

Five patients in each group were lost to follow-up resulting in 40 patients (20 in each group) for continuous evaluation. On postoperative day 21 (study endpoint), no difference regarding success rate (defined as closure of OAC) was noticed between the test (90%; 18/20) and control group (90%; 18/20). A univariate analysis showed significant differences for age and defect size/height for the use of PRF between successful-tight and open-failed defect healing. At the final evaluation, a significantly (p = 0.005) better wound healing score, a lower displacement of the MGB as well as lower pain-score were seen for the use of PRF.

CONCLUSIONS

Based on the findings of the current study, the use of platelet-rich fibrin represents a reliable and successful method for closure of oroantral communications. The use of PRF clots for defect filling is associated with lowered pain levels and less displacement of the mucogingival border.

CLINICAL RELEVANCE

The defect size should be taken into account when choosing the number and size of PRF plugs.

Influence of Er:YAG laser irradiation on the outcomes of alveolar ridge preservation at the infected molar sites: a randomized controlled trial

BACKGROUND

The purpose of this study was to investigate the socket healing outcome after alveolar ridge preservation at infected molar sites using an erbium-doped yttrium aluminium garnet (Er:YAG) laser.

METHODS

Eighteen patients who needed molar extraction and exhibited signs of infection were included and allocated into either the laser group or the control group. Er:YAG laser irradiation for degranulation and disinfection was performed with alveolar ridge preservation (ARP) in the laser group. Traditional debridement with a curette was performed in the control group. Two months after ARP, bone tissue samples were harvested at the time of implant placement for histological analysis. Assessment of dimension changes in alveolar bone was conducted by superimposing two cone-beam computed tomography (CBCT) scans taken at baseline and two months after extraction.

RESULTS

Histologically, after two months of healing, Er:YAG laser treatment resulted in more newly formed bone (laser: 17.75 ± 8.75, control: 12.52 ± 4.99, p = 0.232). Moreover, greater osteocalcin (OCN) positive expression and lower runt-related transcription factor 2 (RUNX-2) positive expression were detected in the laser group. However, no statistically significant difference was observed between the two groups. The difference in the vertical resorption of the buccal bone plate was statistically significant between groups (laser: -0.31 ± 0.26 mm, control: -0.97 ± 0.32 mm, p < 0.05). Major changes in ridge width were observed at 1 mm below the bone crest. However, the differences between groups were not significant (laser: -0.36 ± 0.31 mm, control: -1.14 ± 1.24 mm, p = 0.171).

CONCLUSIONS

ARP with Er:YAG laser irradiation seemed to improve bone healing by regulating osteogenesis-related factor expression in the early stage at infected sites.

TRIAL REGISTRATION

The trial was registered on the Chinese Clinical Trial Registry Platform ( https://www.chictr.org.cn/ ) (registration number: ChiCTR2300068671; registration date: 27/02/2023).

Does the Choice of Preparation Protocol for Platelet-Rich Fibrin Have Consequences for Healing and Alveolar Ridge Preservation After Tooth Extraction? A Meta-Analysis

PURPOSE

Multiple preparation protocols for platelet-rich fibrin (PRF) are in use today, and clinical results are often heterogeneous. This study analyzes the impact of the chosen PRF preparation protocol on 1) wound healing and 2) alveolar ridge preservation.

METHODS

For this systematic review and meta-analysis, eligible studies were identified in PubMed and Cochrane databases. Included were randomized controlled and controlled clinical trials with healthy patients treated with PRF after atraumatic tooth extraction compared to untreated socket(s), reporting at least one of the following outcome variables: pain, swelling, soft tissue healing, alveolar osteitis risk, horizontal and vertical bone loss, socket fill, and new bone formation. Main predictor variable was relative centrifugal force (RCF) comparing high RCF (high PRF), intermediate RCF (standard [S-PRF]), low RCF (advanced PRF), and various RCF settings (concentrated growth factor preparation [CGF]). The type of centrifugation tubes (silica-coated plastic and glass) was a secondary predictor. Weighted or standardized mean differences, risk ratio and corresponding 95% confidence intervals were calculated.

RESULTS

Forty studies published between 2012 and 2022 were selected. The pooled effects of all outcomes were significant against untreated sockets. Within the subgroups high PRF or advanced PRF had the lowest efficacy for many outcome parameters. Pain reduction (in visual analog scale units) was highest for S-PRF (-1.18 [-1.48, -0.88], P < .00001) and CGF (-1.03 [-1.16, -0.90], P < .001). The risk ratio of alveolar osteitis (0.09 [0.01, 0.69], P < .02) and soft tissue healing (standardized mean difference = 2.55 [2.06, 3.03], P < .001) were best for CGF. No subgroup differences were found for bone-related outcomes. No meaningful analysis of the tube material effect was possible.

CONCLUSION

This study confirms that PRF is associated with reduced postoperative complications but indicates that preparation protocol influences clinical outcomes. S-PRF and CGF protocols appear to be superior for several outcome parameters.

Comparative Study of Frequency of Alveolar Osteitis, with and without using Platelet-Rich Fibrin in Mandibular Third Molar Surgery

INTRODUCTION

Alveolar ostitis (AO) is the dissolution of blood clot due to enhanced local fibrinolysis and is caused by trauma to the jaw (direct) or because of bacterial involvement (indirect), which result in the activation of plasminogen pathway. Platelet-rich fibrin (PRF) is a platelet concentrate that comprises numerous autologous growth factors, and immune cells hence has the potential to expedite the healing process. The objective of the study was to determine the efficacy of PRF in the surgically extracted third molar in the context of its potential progress to AO.

MATERIALS AND METHODS

A total of 180 patients of 18-65 years with unilateral painful mandibular third molars due to caries, failed endodontics treatment, and pericoronitis were included in the study. Exclusion criteria were patients who were medically compromised, smokers, alcoholic, poor oral hygiene, third molar having associated periapical pathology, and receiving antibiotic regime in the last 2 weeks. Before starting surgical procedure, patients were randomly divided into two groups using lottery method. Group I received PRF in the extraction socket, while in Group II, the extraction site was left for normal healing as practiced in a standard procedure. Pain was assessed in terms of pain score, and it was recorded on a 10 mm visual analog scale on the first and third postoperative days.

RESULTS

Mean age of the patients was 41.35 ± 9.87 years. The mean age in Group I was 42.84 ± 10.52 years, and in Group II, it was 40.54 ± 9.52 years. Out of 180 patients, 90 (50.0%) were male and 90 (50.0%) were female, with a male-to-female ratio of 1 : 1. Frequency of AO following mandibular third molar surgery in Group I receiving PRF was 2.22% and in non-PRF group 12.22% (p-value = 0.010).

CONCLUSION

The incidence of AO following mandibular third molar surgery was lower when PRF was used.

The effect of dental pulp stem cells and L-PRF when placed into the extraction sockets of impacted mandibular third molars on the periodontal status of adjacent second molars: a split-mouth, randomized, controlled clinical trial

PURPOSE

To compare the clinical and radiographic effectiveness of dental pulp stem cells (DPSCs) seeded onto L-PRF and L-PRF alone in the extraction socket of mandibular third molars.

METHODS

This study analyzed 13 patients who required surgical removal of impacted bilateral mandibular third molars. The main outcome measures were the probing pocket depth (PPD) and clinical attachment levels (CAL) that were recorded for the adjacent second molars (LM2) at the baseline and 6 months after surgery. The secondary outcomes were radiographic vertical bone loss (VD) and relative bone density (rBD) distal to the LM2.

RESULTS

Twenty-six LM2s were evaluated. After 6 months, the L-PRF and L-PRF + DPSC groups showed a significant reduction in PPD (1.65 ± 1.01 mm and 1.54 ± 0.78 mm) and CAL (2.23 ± 1.45 mm and 2.12 ± 0.74 mm), respectively. There was no difference between the groups for any periodontal parameters. No significant differences were found between the groups regarding the VD or rBD at the sixth month.

CONCLUSIONS

This study found that there was a significant improvement regarding the PPD, CAL, and VD measurements with the application of L-PRF, both alone and with the addition of DPSC, at the extraction socket. DPSC did not significantly contribute to the results compared to L-PRF therapy alone.

TRIAL REGISTRATION

This study was registered on 23 December 2020 on ClinicalTrials.gov under the number NCT04641533.

Comparative Effects of Different Materials on Alveolar Preservation

OBJECTIVE

The purpose of this study was to compare different materials' effects on alveolar ridge preservation of postextraction sockets in anterior maxilla.

MATERIALS AND METHOD

In this prospective, single center, randomized, controlled clinical trial, healthy patients who needed one single anterior maxillary tooth extraction (including bicuspids) were selected. After a minimally traumatic extraction without complications, 44 patients were randomly allocated into 4 groups: 1) natural socket healing (blood clot), 2) xenograft and gingival free graft, 3) dense polytetrafluoroethylene membrane, and 4) platelet rich fibrin plugs. Alveolar ridge height and width loss were evaluated in cone beam computed tomography (CBCT) and in dental casts at 3 moments: 1) preoperative (T1), 2) 7 days postoperative (T2), and 3) 120 days postoperative (T3). Height and width alveolar ridge loss detected in CBCT and in dental casts were compared among the groups (two-way analysis of variance [ANOVA]; P < .05).

RESULTS

Forty patients (24 women and 16 men) ranging from 25 to 70 years old (mean of 42 years old) participated in this study. Group 2 showed the least alveolar ridge height loss results in CBCT (9.8 ± 1.9% at T3) and dental cast analysis (1.0 ± 0.2 mm). Groups 2 (12.7 ± 4.7% at T3) and 3 (15.4 ± 2.7% at T3) showed the least alveolar ridge width loss measured in CBCT compared with groups 1 and 4, but the difference between groups 2 and 3 were not statistically significant (P = .968). Group 3 (0.9 ± 0.2 mm) and group 2 (1.0 ± 0.2 mm) showed the least width loss compared with groups 1 and 4 in dental cast analysis. Again, the difference between groups 3 and 2 was not statistically significant (P = 1.000).

CONCLUSION

In postextraction sockets of the anterior maxilla and bicuspid region, group 2 (xenogenous bone graft with free gingival graft) and group 3 (dense polytetrafluoroethylene) obtained the best results in alveolar preservation, with group 2 being more indicated when the vertical alveolar ridge preservation is mandatory.

Comparative analysis of the effect of 4MATRIX with and without PRF on regeneration of infrabony periodontal pockets

Aim

The aim was to compare the effect in improvement of periodontal pocket depth (PPD) and clinical attachment level (CAL) between application of 4MATRIX and 4 MATRIX combined with PRF in advanced periodontal disease during follow-up of 6, 12 and 18 months.

Methods

Thirty patients of both genders aged 25-50 years were included. The patients were clinically and radiologically diagnosed with generalized advanced chronic periodontitis with the presence of periodontal pockets with a depth of ≥ 5 mm bilaterally in the upper jaw. Both sides were treated with a flap intervention in all patients. On one side a bone substitute 4MATRIX was applied, and the other side was treated with an application 4MATRIX and PRF. The clinical assessment and measurements were performed in four stages, immediately before the intervention, and then 6, 12 and 18 months after the intervention. PPD and CAL were determined in all four timepoints.

Results

PPD was the highest at zero time before the surgery for both groups and was 5.56 ± 0.28 mm. In the postoperative follow-up period, the PPD value decreased gradually with the lowest average value of 5.10 ± 0.18 mm after 18 months in Group I and 4.67 ± 0.13 mm in Group II (p < 0.001, respectively). Moreover, comparing the values of PPD at 6, 12 and 18 months after the surgery, a significant difference was found between the patients from the 4MATRIX vs 4MATRIX + PRF (p < 0.001 respectively). The postoperative follow-up period showed a decrease in CAL value with the lowest value after 18 months. A significant difference in CAL was found between the four measurement times (p < 0.001, respectively). The average level of CAL was the highest before surgical treatment in both groups. The intergroup analysis of CAL after 18 months in group I (4MATRIX) was 5.27 ± 0.17 mm and in group II 4.10 ± 0.14 mm (p < 0.001).

Conclusion

Treatment of adult patients with advanced chronic periodontitis with periodontal pockets of ≥ 5 mm bilaterally in the upper jaw using 4MATRIX and 4MATRIX + PRF showed improvement of PPD and lower CAL loss after 18 months of the treatment. In the group treated with 4MATRIX + PRF patients showed the highest improvement in PPD and CAL loss. The analysis of treatment with 4MATRIX and 4MATRIX + PRF showed the lowest values after 18 months of the treatment.

Can Our Blood Help Ensure Antimicrobial and Anti-Inflammatory Properties in Oral and Maxillofacial Surgery?

In recent decades, the potential of PRF has been extensively studied. The number of studies about PRF has increased three times since the year 2012, but the full spectrum of its fundamental properties, such as antimicrobial and anti-inflammatory activity, is not clearly described. In oral and maxillofacial surgery, PRF is described in alveolar ridge preservation, orthognathic surgery, cleft lip and palate surgery, maxillary sinus augmentation, and dental implant placement as demonstrating favorable results and its clinical advantages. The structural complexity, inhomogeneous nature, and clotting ability of PRF make its antimicrobial effect evaluation complicated. Nevertheless, most of the used antimicrobial testing methods are based on antibacterial agent diffusion ability in culture media. Because the oral and maxillofacial region is the most frequent area of PRF application, its antimicrobial activity evaluation also prevails in the oral microbiome. PRF's biological potential is highly dependent on the specific preparation protocol and methodology used; it should be carefully prepared and kept under proper conditions to keep cellular content alive. PRF's influence on living cells demonstrates a stimulating effect on bone regeneration, and an angiogenetic effect, and it provides anti-inflammatory activity. According to analyzed studies, PRF demonstrated success in oral and maxillofacial surgery in various methods of application. Antibacterial and anti-inflammatory properties were proven by antibacterial activity against different bacterial species, sustained growth factor, sustained release, and cell activity on the material application. Accurately and correctly prepared PRF can ensure antibacterial and anti-inflammatory properties, and it can be a beneficial clinical tool in oral and maxillofacial surgery.

Effect of leukocyte-platelet-rich fibrin in bone healing around dental implants placed in conventional and wide osteotomy sites: A pre-clinical study

Leukocyte-platelet-rich fibrin (L-PRF) has been suggested for gap management for immediate implant placement when the distance is greater than 2 mm. However, there remains a paucity in hierarchically designed research to support this application. The present study aimed to evaluate the effect of L-PRF on the osseointegration parameters of dental implants placed after conventional osteotomy of surgically created bone defects that simulate post extraction sockets in a canine model after 3, 6, and 12 weeks in vivo. Eighty dental implants (Intra-Lock, Boca Raton, FL) were placed in the radius of 13 beagle dogs. The experiment consisted of 4 groups (n = 20 implants/group): 1) Regular osteotomy (Reg n/L-PRF); 2) Regular osteotomy and implant placement with L-PRF membrane (Reg L-PRF); 3) Wide osteotomy with no gap management performed, where an osteotomy/bony defect (6 mm of diameter and ~5 mm deep) was created to simulate immediate implant placement in post-extraction sockets, and the gap was left for spontaneous healing (Wide nL-PRF); and 4) Wide osteotomy with L-PRF gap management (Wide L-PRF). L-PRF membranes were obtained by blood drawn from each subject and centrifuged at 2700 rpm (408 RCF-clot) for 12 min. In the experimental groups where L-PRF was utilized, the membrane was inserted into the osteotomy site prior to implant placement. Six dogs had implants placed in the radius for 3 weeks; and 7 dogs had implants placed in the left radius for 6 weeks and in the right radius for 12 weeks. At the corresponding experimental time points, samples were harvested, and subjected to histological processing for qualitative and quantitative analyses, via bone-to-implant contact (BIC) and bone-area-fraction occupancy (BAFO). Qualitative analysis demonstrated increased amounts of bone formation around the implant and within the healing chambers over time for all groups. While comparable histological features were observed for both Reg groups (L-PRF and nL-PRF), the gap management performed in Wide L-PRF group resulted in effective gap filling with improved bone growth in close proximity to the implant surface. Quantitative analyses of BIC and BAFO yielded higher values for both variables at 3 weeks for Wide L-PRF (~38% and ~56% respectively) compared to Wide nL-PRF (~20% for BIC and BAFO) (p < .03). No statistical differences were detected between Wide groups at 6 and 12 weeks, neither between Reg groups, independent of the association with or without the L-PRF membrane at all healing times. L-PRF placed within wide osteotomies, prior to implant placement, resulted in increased early bone formation compared to unfilled wide osteotomies at the early healing time (3 weeks in vivo).

Regenerative Potential of Platelet Rich Fibrin (PRF) in Socket Preservation in Comparison with Conventional Treatment Modalities: A Systematic Review and Meta-Analysis

BACKGROUND

Platelet rich fibrin (PRF) has shown great potential in osteogenesis; however, some studies still question utilizing it as a grafting material. Thus, the aim of this review is to evaluate the effect of PRF when used in socket and ridge preservation procedures.

METHODS

Electronic searches through MEDLINE, EMBASE, and Cochrane, Science Citation Index Expanded databases and manual searches of unpublished data, academic theses, and journals were conducted up until July 2021. The outcomes were to assess the ability of PRF as a graft material to preserve bone width, height, and density after tooth extraction.

RESULTS

Twelve studies were included in the review, using PRF showed significant results in all three outcomes when compared to no grafting at all, however when compared to other commonly used grafting materials it showed a lesser effect. On the other hand, most studies included reported mixing PRF with a graft material showed the best result. The meta-analysis also revealed the significant results in using PRF on the three outcomes.

CONCLUSION

The meta-analysis of the studies included proved the beneficial effect of PRF in socket preservation surgeries alone or in combination with other graft materials, but further individual multi-centre randomized controlled studies with appropriate sample size are still needed to further confirm our findings.

Radicectomy of radix entomolaris: An alternative treatment approach for persistent periapical lesion assisted by cone-beam computed tomography and operating microscope

Every clinician as well as patient would prefer to sustain their natural teeth in all situations. For a badly mutilated terminal abutment, molar treatment options are limited, but loss of posterior tooth can lead to several unwanted sequelae. A guiding principle should be to preserve what is present. If complete preservation is not possible, the most conservative treatment should follow in every clinical situation. Radisectomy is one such conservative surgical treatment approach that allows resection of one or more affected roots of tooth at the level of furcation and preserves the remaining roots and the complete crown structure, thereby maintaining the occlusal harmony. Hereby, we are presenting a case report on radicectomy of distobuccal root of a mandibular third molar with persistent periradicular pathosis, with the assistance of microscope and cone-beam computed tomography.

Platelet-Rich Fibrin Used in Regenerative Endodontics and Dentistry: Current Uses, Limitations, and Future Recommendations for Application

Regenerative endodontics has introduced numerous procedures such as pulp implantation, revascularization, and postnatal stem cell therapy. Revascularization has been successfully implemented clinically nowadays, thus providing dentists with outrageous results. Platelet-rich fibrin (PRF) used either alone or along with bone graft promotes bone growth and vascularization. This matrix promotes migration, cell attachment, and proliferation of osteoblast that leads to bone formation. PRF consists of a packed fibrin complex consisting of leukocytes, cytokines, and glycoproteins such as thrombospondin. The usage of PRF has reported high success rates in surgical cases such as sinus lift procedures, healing of extraction sockets, and management of periapical abscesses. Compared to platelet-rich plasma, PRF is more economical, easy to prepare, and feasible to use in daily clinical practices. Revascularization compromised the induction of a blood clot into the root canal space, which emerged as a clinical triumph. This further led to platelet concentrates as an autologous scaffold on which revascularization could occur. The applications of PRF in regenerative endodontics are numerous, such as an agent for repairing iatrogenic perforation of the pulpal floor and for the revascularization of immature permanent teeth with necrotic pulps. It acts as a matrix for tissue ingrowth. Evidence of progressive thickening of dentinal walls, root lengthening, regression in the periapical lesion, and apical closure was reported. Further studies are needed to clarify the precise mechanism of action of PRF for dental pulp regeneration both in vitro and in vivo. The current review aims at the present uses of PRF in regenerative endodontics dentistry and its application with future recommendations and limitations.

Efficacy of platelet-rich fibrin in promoting the healing of extraction sockets: a systematic review

PURPOSE

To address the focused question: in patients with freshly extracted teeth, what is the efficacy of platelet-rich fibrin (PRF) in the prevention of pain and the regeneration of soft tissue and bone compared to the respective control without PRF treatment?

METHODS

After an electronic data search in PubMed database, the Web of Knowledge of Thomson Reuters and hand search in the relevant journals, a total of 20 randomized and/or controlled studies were included.

RESULTS

66.6% of the studies showed that PRF significantly reduced the postoperative pain, especially in the first 1-3 days after tooth extraction. Soft tissue healing was significantly improved in the group of PRF compared to the spontaneous wound healing after 1 week (75% of the evaluated studies). Dimensional bone loss was significantly lower in the PRF group compared to the spontaneous wound healing after 8-15 weeks but not after 6 months. Socket fill was in 85% of the studies significantly higher in the PRF group compared to the spontaneous wound healing.

CONCLUSIONS

Based on the analyzed studies, PRF is most effective in the early healing period of 2-3 months after tooth extraction. A longer healing period may not provide any benefits. The currently available data do not allow any statement regarding the long-term implant success in sockets treated with PRF or its combination with biomaterials. Due to the heterogeneity of the evaluated data no meta-analysis was performed.

Dimensional and histomorphometric evaluation of biomaterials used for alveolar ridge preservation: a systematic review and network meta-analysis

OBJECTIVES

This systematic review and network meta-analysis aimed to answer to the following questions: (a) In patients undergoing alveolar ridge preservation after tooth extraction, which grafting material best attenuates horizontal and vertical ridge resorption, as compared to spontaneous healing?, and (b) which material(s) promotes bone formation in the extraction socket?

MATERIALS AND METHODS

The MEDLINE, SCOPUS, CENTRAL, and EMBASE databases were screened in duplicate for RCTs up to March 2021. Two independent authors extracted the data and assessed the risk of bias of the included studies. Primary outcomes were ridge horizontal and vertical dimension changes and new bone formation into the socket. Both pairwise and network meta-analysis (NMA) were undertaken to obtain estimates for primary outcomes and compare different grafting materials.

RESULTS

Eighty-eight RCTs were included, with a total of 2805 patients and 3073 sockets. Overall, a total of 1740 sockets underwent alveolar ridge preservation with different materials (1432 were covered by a membrane). Pairwise meta-analysis showed that, as compared to spontaneous healing, all materials statistically significantly reduced horizontal and vertical shrinkage. According to the multidimensional scale ranking of the NMA, xenografts (XG) and allografts (AG), alone or combined with bioactive agents (Bio + AG), were the most predictable materials for horizontal and vertical ridge dimension preservation, while platelet concentrates performed best in the percentage of new bone formation.

CONCLUSIONS

Alveolar ridge preservation is effective in reducing both horizontal and vertical shrinkage, as compared to untreated sockets. NMA confirmed the consistency of XG for ridge dimension preservation, but several other materials and combinations like AG, Bio + AG, and AG + alloplasts, produced even better results than XG in clinical comparisons. Further evidence is needed to confirm the value of such alternatives to XG for alveolar ridge preservation. Bio + AG performed better than the other materials in preserving ridge dimension and platelet concentrates in new bone formation. However, alloplasts, xenografts, and AG + AP performed consistently good in majority of the clinical comparisons.

CLINICAL RELEVANCE

XG and Bio + AG demonstrated significantly better performance in minimizing post-extraction horizontal and vertical ridge dimension changes as compared with other grafting materials or with spontaneous healing, even if they presented the worst histological outcomes. Allografts and other materials or combinations (AG + AP) presented similar performances while spontaneous healing ranked last.

Comparison of quality of bone and insertion torque values of early implants placed at 6 and 8 weeks in sockets preserved with advanced platelet-rich fibrin: A randomized controlled trial

Aim

Successful functional and esthetic rehabilitation of edentulous jaws with implants depends on the optimal timing of placement, surgical protocol, materials used, cost-effectiveness, and satisfying patient needs. Increasing demand for shorter treatment times necessitates the immediate placement protocol. However, researchers have demonstrateda higher failure rate. A-PRF (Advanced platelet-rich fibrin) has exhibited accelerated bone regeneration potential. Early implant placement with a limited healing period, along with A-PRF, can be beneficial over conventional and immediate implant placement.

Settings and Design

This prospective randomized clinical trial aims to assess the outcome of early implant placement in sockets preserved using A-PRF at six weeks and eight weeks of post-extraction. Two groups of 10 participantseach were formed. All patients underwent atraumatic extraction and socket preservation using A-PRF.

Materials and Methods

A Partial-thickness pedicle graft was raised, and the extraction socket wasclosed. Implants wereplaced in at six and eight weeks of post-extraction in group A group B, respectively. The histomorphometric analysisassessedthe bone quality present at the timeof surgery. The insertion torque values were recorded during implant placement.

Statistical Analysis Used

The obtained data were statistically analyzed using parametric tests, namely independent T-test for intergroup comparison.

Results

T-test for torque values indicated a significantly higher torque value at eight weeks. The meanhistomorphometric value showeda significantly higher percentage of bone formation at eight weeks than at six weeks (P = 0.03).

Conclusion

Within the study's limitations, early implant placement in extraction sockets preserved with A-PRF had significantly higher insertion torque values and predictable bone at eight weeks compared to six weeks.

Structure, Barrier Function, and Bioactivity of Platelet-Rich Fibrin Following Thermal Processing

Platelet-rich fibrin (PRF) has been utilized as a substitute for resorbable membranes during guided bone regeneration therapy as it is a more bioactive biomaterial with living cells and growth factors than resorbable membranes. Nevertheless, PRF poses obvious disadvantages in its mechanical strength since its rapid degradability has been shown to typically resorb within a 2-week time period. In the present study, the barrier function and biological and mechanical properties of PRF were investigated both as standard therapy and after thermal processing. Two heating processes were applied: both single-side heating and double-side heating at 90°C for 10 s using a metal plate heater. The appearance and weight of PRF membranes were documented after heating, along with their morphological and mechanical properties evaluated by scanning electron microscope and tensile strength tests. The viability of cells found within PRF membranes was also evaluated using live/dead cell viability and CCK-8 (cell counting kit-8) assays. To comprehensively evaluate the barrier function of PRF membranes, Hoechst staining of human gingival fibroblasts, which can be distinguished from cells within the PRF membrane by emitting blue light at an excitation wavelength of 488 nm, was seeded onto the surface of PRF membranes. Furthermore, osteoblasts were cultured with extracts from different PRF groups to evaluate the biocompatibility of PRF membranes. The degradation rate of PRF membranes was examined by digestion assay. Compared with the nonheated PRF control, the size and weight of PRF membranes led to a significant decrease with a denser PRF microstructure following heating. In summary, the double-sided heating of PRF membranes not only demonstrated an improvement in mechanical and degradation properties but also led to a decrease in cell viability and proliferation.

The impact of autologous concentrated growth factors on the alveolar ridge preservation after posterior tooth extraction: A prospective, randomized controlled clinical trial

BACKGROUND

Alveolar ridge preservation can effectively decrease alveolar ridge resorption following tooth extraction, but it can be limited by reducing new bone formation and residual bone graft material. Efforts to develop more efficacious approaches are thus an area of active research.

PURPOSE

To assess the impact of autologous concentrated growth factors (CGF) on alveolar ridge absorption and osteogenesis following posterior tooth extraction.

MATERIALS AND METHODS

Fifty patients were randomly assigned to have extraction sockets treated with CGF or no treatment. At 10 days, 1 month, and 3 months postextraction, soft tissue color and texture were examined and evaluated with healing score. Cone-beam computed tomography (CBCT) scans were performed before and 3 months after extraction, while radiographic analyses were used to assess vertical and horizontal bone changes. Bone samples were collected from the extraction sockets during implant placement, and micro-computed tomography (micro-CT) scans and histological analysis were performed to evaluate new bone formation. t-Test or Mann-Whitney U test was used to compare data and the level of statistical significance was set at 0.05 for all analyses.

RESULTS

Forty-six patients completed the trial. Sockets in the experimental group exhibited significantly better healing score on Day 10 postextraction relative to the control group, whereas comparable healing was observed in both groups at 1 and 3 months postextraction. Experimental group exhibited reduced vertical bone changes relative to the control (p < 0.05). Significant reductions were observed in ridge width changes at 1 and 2 mm apical to the crest (p < 0.05), although differences at 3 and 5 mm apical to the crest were not significant. Significant differences of bone mineral density (BMD) and microarchitecture of trabecular bone were observed via micro-CT analyses, and the experimental group had better results.

CONCLUSION

CGF application following posterior tooth extraction may reduce vertical and horizontal bone resorption and promote new bone formation.

Flapped versus flapless alveolar ridge preservation: a systematic review and meta-analysis

Alveolar ridge preservation (ARP) procedures can limit bone changes following tooth extraction. Flapped and flapless surgical approaches have been used for ARP; however, there is a lack of strong scientific evidence regarding their specific influences on the clinical outcomes of ARP. The aim of this systematic review and meta-analysis was to evaluate the effects of flapped and flapless surgical approaches on the dimensional changes of hard and soft tissues and patient-reported outcomes following ARP. Electronic databases were searched to identify randomized controlled trials (RCTs) that compared flapped ARP by means of a coronally advanced flap to flapless ARP where barrier membranes were left exposed. The risk of bias was assessed using the Cochrane Collaboration Risk of Bias tool. Data were analysed using a statistical software program. A total of 754 studies were identified, of which five studies with 149 extraction sockets in 128 participants were included. Overall, meta-analysis did not show any significant differences in the changes in ridge width or height between flapped and flapless ARP. The use of flapless ARP was associated with significantly less postoperative pain, thicker labial soft tissues, and marginally more favourable changes in width of the keratinized tissues compared to the flapped approach. The short-term hard tissue changes following ARP with a flapped or flapless approach are comparable. Postoperative pain and labial soft tissue changes are more favourable following ARP using a flapless approach. Further evidence from long-term RCTs is still required to substantiate the current findings.

Effects of relative centrifugation force on L-PRF: An in vivo submandibular boney defect regeneration study

Properties and composition of leukocyte- and platelet-rich fibrin (L-PRF) clots may be largely affected by centrifugation protocols (function of relative centrifugal force [RCF]), which may impact biological potential repair in bone regeneration. The present in vivo study sought to assess the effect of the RCF on the composition of L-PRF clots, as well as to compare the repair potential of L-PRF clots obtained with different RCF protocols in submandibular boney defects using PLGA scaffolds for bone regeneration. Complete blood count and volumetric evaluations were performed on L-PRF clots obtained through centrifugation for 12 min at 200, 400, and 600 RCF-clot centrifugation speeds. These evaluations were completed from blood collected immediately prior to any surgical procedures. The in vivo portion comprised of three submandibular unilateral, full thickness, osteotomies (~0.40cm³ ) which were created in the submandibular region of six sheep, using rotary instrumentation under continuous irrigation. Subsequently, poly(lactic-co-glycolic acid) (PLGA) scaffolds were enveloped in a L-PRF membrane from one of the three spinning speeds (n = 6/RCF) and inserted into the defect (sites were interpolated to avoid site bias). Six-weeks after surgery, the mandibles were harvested en bloc and prepared for volumetric and histomorphometric evaluations. Membranes harvested from 600 RCF produced significantly larger L-PRF clots (6.97g ± 0.95) in comparison to the lower 200 RCF (5.7g ± 0.95), with no significant differences between 600 and 400, and from 400 and 200 RCF. The three tested RCFs did not alter the platelet count of the L-PRF clot. For the in vivo component, quantitative bone regeneration analyses demonstrated significantly higher values obtained with L-PRF membranes extracted post 600 RCF (27.01 ± 8%) versus 200 RCF (17.54 ± 8%), with no significant differences regarding 400 RCF (~23 ± 8%). At the qualitative histological analyses, L-PRF membranes obtained at 600 and 400 RCFs yielded improved healing throughout the defect, where the L-PRF sourced from the lowest speed, 200 RCF, presented healing primarily at the margins along with the presence of connective tissue at the central aspect of the surgical defect. Higher 600 RCF yielded larger L-PRF clots/membranes, resulting in enhanced bone repair potential in association with PLGA scaffolds for the treatment of critical size bone defects.

Interventions for replacing missing teeth: alveolar ridge preservation techniques for dental implant site development

BACKGROUND

Alveolar bone changes following tooth extraction can compromise prosthodontic rehabilitation. Alveolar ridge preservation (ARP) has been proposed to limit these changes and improve prosthodontic and aesthetic outcomes when implants are used. This is an update of the Cochrane Review first published in 2015.

OBJECTIVES

To assess the clinical effects of various materials and techniques for ARP after tooth extraction compared with extraction alone or other methods of ARP, or both, in patients requiring dental implant placement following healing of extraction sockets.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 19 March 2021), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2021, Issue 2), MEDLINE Ovid (1946 to 19 March 2021), Embase Ovid (1980 to 19 March 2021), Latin American and Caribbean Health Science Information database (1982 to 19 March 2021), Web of Science Conference Proceedings (1990 to 19 March 2021), Scopus (1966 to 19 March 2021), ProQuest Dissertations and Theses (1861 to 19 March 2021), and OpenGrey (to 19 March 2021). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. A number of journals were also handsearched.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) on the use of ARP techniques with at least six months of follow-up. Outcome measures were: changes in the bucco-lingual/palatal width of alveolar ridge, changes in the vertical height of the alveolar ridge, complications, the need for additional augmentation prior to implant placement, aesthetic outcomes, implant failure rates, peri-implant marginal bone level changes, changes in probing depths and clinical attachment levels at teeth adjacent to the extraction site, and complications of future prosthodontic rehabilitation.

DATA COLLECTION AND ANALYSIS

We selected trials, extracted data, and assessed risk of bias in duplicate. Corresponding authors were contacted to obtain missing information. We estimated mean differences (MD) for continuous outcomes and risk ratios (RR) for dichotomous outcomes, with 95% confidence intervals (95% CI). We constructed 'Summary of findings' tables to present the main findings and assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 16 RCTs conducted worldwide involving a total of 524 extraction sites in 426 adult participants. We assessed four trials as at overall high risk of bias and the remaining trials at unclear risk of bias. Nine new trials were included in this update with six new trials in the category of comparing ARP to extraction alone and three new trials in the category of comparing different grafting materials. ARP versus extraction: from the seven trials comparing xenografts with extraction alone, there is very low-certainty evidence of a reduction in loss of alveolar ridge width (MD -1.18 mm, 95% CI -1.82 to -0.54; P = 0.0003; 6 studies, 184 participants, 201 extraction sites), and height (MD -1.35 mm, 95% CI -2.00 to -0.70; P < 0.0001; 6 studies, 184 participants, 201 extraction sites) in favour of xenografts, but we found no evidence of a significant difference for the need for additional augmentation (RR 0.68, 95% CI 0.29 to 1.62; P = 0.39; 4 studies, 154 participants, 156 extraction sites; very low-certainty evidence) or in implant failure rate (RR 1.00, 95% CI 0.07 to 14.90; 2 studies, 70 participants/extraction sites; very low-certainty evidence). From the one trial comparing alloplasts versus extraction, there is very low-certainty evidence of a reduction in loss of alveolar ridge height (MD -3.73 mm; 95% CI -4.05 to -3.41; 1 study, 15 participants, 60 extraction sites) in favour of alloplasts. This single trial did not report any other outcomes. Different grafting materials for ARP: three trials (87 participants/extraction sites) compared allograft versus xenograft, two trials (37 participants, 55 extraction sites) compared alloplast versus xenograft, one trial (20 participants/extraction sites) compared alloplast with and without membrane, one trial (18 participants, 36 extraction sites) compared allograft with and without synthetic cell-binding peptide P-15, and one trial (30 participants/extraction sites) compared alloplast with different particle sizes. The evidence was of very low certainty for most comparisons and insufficient to determine whether there are clinically significant differences between different ARP techniques based on changes in alveolar ridge width and height, the need for additional augmentation prior to implant placement, or implant failure. We found no trials which evaluated parameters relating to clinical attachment levels, specific aesthetic or prosthodontic outcomes for any of the comparisons. No serious adverse events were reported with most trials indicating that the procedure was uneventful. Among the complications reported were delayed healing with partial exposure of the buccal plate at suture removal, postoperative pain and swelling, moderate glazing, redness and oedema, membrane exposure and partial loss of grafting material, and fibrous adhesions at the cervical part of previously preserved sockets, for the comparisons xenografts versus extraction, allografts versus xenografts, alloplasts versus xenografts, and alloplasts with and without membrane.

AUTHORS' CONCLUSIONS

ARP techniques may minimise the overall changes in residual ridge height and width six months after extraction but the evidence is very uncertain. There is lack of evidence of any differences in the need for additional augmentation at the time of implant placement, implant failure, aesthetic outcomes, or any other clinical parameters due to lack of information or long-term data. There is no evidence of any clinically significant difference between different grafting materials and barriers used for ARP. Further long-term RCTs that follow CONSORT guidelines (www.consort-statement.org) are necessary.

Effect of different platelet-rich fibrin matrices for ridge preservation in multiple tooth extractions: A split-mouth randomized controlled clinical trial

AIM

To evaluate dimensional changes in the alveolar ridge and bone structure after tooth extraction when L-PRF or A-PRF+ was used in comparison to unassisted socket healing.

MATERIALS AND METHODS

Twenty patients in need of at least three tooth extractions in the aesthetic zone were included. L-PRF, A-PRF+ or control was randomly assigned, leaving one empty socket/edentulous site between conditions. CBCT scans were obtained immediately after tooth extraction and after 3 months of healing. Horizontal and vertical dimensional changes of the ridge and socket fill were calculated. Histological and micro-CT analysis of bone biopsies were used to evaluate post-surgical bone structural healing.

RESULTS

Mean horizontal and vertical changes at 1-mm below the crest (buccal and palatal side) were similar for the three sites (p > 0.05). For the socket fill, L-PRF (85.2%) and A-PRF+ (83.8%) showed superior values than the control (67.9%). The histological and radiological analysis reported more newly formed bone for the PRF groups, without any significant differences between both.

CONCLUSIONS

PRF matrices failed to reduce the dimensional changes after multiple tooth extractions in the premaxilla. After 3-month healing, both PRF matrices showed radiographically a significant superiority for the socket fill. Histologically, they seemed to accelerate new bone formation.