Platelet-Rich Plasma in Maxillary Sinus Augmentation: Systematic Review

Insights into Sinus-Lift Bone Grafting Materials: What's Changed?

BACKGROUND

Sinus-lift (SL) is a pre-prosthetic procedure with the objective of increasing bone height to achieve implant insertion primary stability in implant-supported prostheses. The biomechanical properties of SL augmentation materials are influenced by their origin, manufacture, bioactive substances addition, receiver, and surgical procedure. This systematic review provides insights into state-of-the-art SL biomaterials, focusing on autologous bone grafting as the gold standard.

METHODS

The study followed the PRISMA flow diagram, searching WoS (Web of Science), Embase, Cochrane, and PubMed databases using the search terms «sinus lift» OR «sinus augmentation» OR «bone graft» OR «bovine» OR «porcine» OR «autologous» OR «allogenic» OR «xenogeneic» OR «alloplastic» OR «hydroxyapatite» OR «β-tricalcium phosphate (β-TCP)» OR «equine» OR «PRF».

RESULTS

The highest bone gain was provided by Bioglass at 42%. Articles written between 2014 and 2024 in English or French, containing human studies and with full text available, were included. Participants were required to be in good general health, without acute, chronic, or congenital diseases, or substance abuse (drugs, alcohol, or nicotine). SL surgery was performed using the lateral approach, with no Schneiderian membrane perforation or postoperative complications. The network meta-analysis was conducted using the R statistical computing environment. To assess the inconsistency between direct and indirect evidence, we used a net heat plot. To evaluate heterogeneity across studies, we used the chi-squared-based Q-test and I2 statistic. A significance level of 0.05 was applied throughout all analyses.

RESULTS

Allogeneic bovine bone and hydrox yapatite demonstrated the lowest resorption rates. Significant differences were found for residual graft and connective tissue between allogenous bovine bone (ABB) + AlB vs. β-TCP + PRF (p = 0.028); ABB + AlB vs. β-TCP (p = 0.034); ABB + AlB vs. BCP (p = 0.037). Meta-analysis showed that the overall heterogeneity was 51.8% (6.9-75%; p = 0.019), with significant heterogeneity within designs (p = 0.007) and no significant heterogeneity between designs (p = 0.39). AB had a better bone regeneration ratio compared to many of the other interventions, but only two passed the threshold of significance: A1B and B-TCP + AB.

CONCLUSIONS

A grafting material's superiority is determined by its new bone formation ratio, connective tissue integration, residual graft content, and bone resorptionratio. Although autologous bone grafting has exhibited superior bone regeneration compared to other biomaterials, it was not favored due to its unpredictable connective tissue concentration and bone resorption ratio. Additionally, autologous bone exhibited the fastest metabolic turnover among all grafting materials.

Bibliometric Analysis of Platelet-Rich Plasma Treatment for Hair Restoration, Facial Rejuvenation, Dental Procedures, and Gynecological Rejuvenation

Introduction

Autologous platelet-rich plasma (PRP) technologies offer an attractive treatment option for various medical fields. Owing to its high concentration of growth factors, PRP has been posited to induce proliferation, differentiation, and angiogenesis at the cellular level, as well as wound-healing and remodeling at the tissue level. The goal of the present bibliometric analysis was to characterize the growing body of literature concerning PRP use in various medical applications.

Methods

A comprehensive literature search was performed on June 28, 2024, using Web of Science and SCOPUS databases, covering all available publications in selected categories from 2001 to present.

Results

PRP use for hair restoration had both the greatest number of total publications among the investigated applications, whereas PRP use in dental procedures had the longest-standing history of publications. PRP use in hair restoration and facial rejuvenation had the greatest number of placebo-controlled and double-blinded randomized controlled trials; however, the impact of results may suffer from a lack of consistency in PRP preparation and outcome measurement between different studies.

Conclusion

To effectively validate the utility of PRP across various medical interventions, careful consideration of methodology should be undertaken for future studies to ensure validity of results.

Clinical, Radiological, and Histomorphometric Comparison of the Use of Deproteinized Bovine Bone Mineral and Titanium-Prepared Platelet-Rich Fibrin in Maxillary Sinus Augmentation: A Split-Mouth Randomized Controlled Clinical Study

BACKGROUND

Maxillary sinus augmentation (MSA) is a standard and predictable procedure to increase bone height in the atrophic posterior maxilla. Many biomaterials are employed in this technique; however, autologous platelet concentrates have been found to reduce clinical recovery time and improve bone gain in MSA.

PURPOSE

This study aimed to compare the radiographic, histomorphometric, and implant stability outcomes of titanium-prepared platelet-rich fibrin (T-PRF) and deproteinized bovine bone mineral (DBBM) in a two-stage MSA technique.

STUDY DESIGN, SETTING, SAMPLE

This randomized controlled split-mouth study included patients requiring bilateral two-stage MSA at the Periodontology Department of Kutahya Health Sciences University between March 2022 and April 2023. Patients with systemic comorbidities and residual bone height >5 mm in the bilateral posterior maxilla were excluded.

PREDICTOR VARIABLE

The predictor variable was the two-stage MSA technique. Each surgical site was randomly assigned to the T-PRF or DBBM group for two-stage MSA.

MAIN OUTCOME VARIABLES

The primary outcome was the histomorphometric evaluation of the percentage of new bone between the 2 groups. Secondary outcomes included radiographic evaluation of total bone height (ToBH), bone gain, bone density (BD), and graft volume (GV) on cone-beam computed tomography 6 months post-MSA, clinical assessment of primary implant stability at implant placement and secondary stability 3 months postplacement, and histomorphometric evaluation of the percentage of residual particles, percentage of connective tissue, and percentage of blood vessels from bone biopsy samples collected 6 months after MSA.

COVARIATES

Age, sex, periodontitis susceptibility, and smoking status were treated as covariates.

ANALYSES

The Wilcoxon signed-rank test was used for bivariate comparisons between 2 groups, and the Pearson or Spearman test was used to analyze correlations of variables within groups. A P value ≤ .05 was considered statistically significant.

RESULTS

The sample was composed of 10 patients with bilateral maxillary sinuses, 20 MSA regions, 8 (80%) males and 2 (20%) females with a mean age of 51.30 (9.06) year. The percentage of new bone was 19.48 ± 14.60 μm2 in the T-PRF group and 8.31 ± 5.47 μm2 in the DBBM group, and there was no statistically significant difference between the groups (P = .074). Radiographic measurements showed ToBH, GV, and BD values of 10.64 ± 3.96 mm, 989.89 ± 523.07 mm3, and 192.09 ± 127.90 hounsfield unit in the T-PRF group and 14.25 ± 1.65 mm, 1,519.39 ± 432.61 mm3, and 492.77 ± 117.35 hounsfield unit in the DBBM group, respectively. ToBH, GV, and BD values were statistically significant between the groups (P = .01 and P = .00). Primary and secondary implant stability in the T-PRF group were 71.11 ± 12.48 implant stability quotient (ISQ) and 68.03 ± 6.81 ISQ, respectively, compared with 67.94 ± 19.84 ISQ and 72.46 ± 11.21 ISQ in the DBBM group. The difference was not statistically significant between the groups (P = .41 and P = .33).

CONCLUSION AND RELEVANCE

Although T-PRF demonstrated inferior radiographic outcomes compared with DBBM during the initial6-month healing phase, both techniques yielded comparable results regarding new bone formation and implant stability. Further research is warranted to explore the efficacy of different T-PRF applications in MSA. This trial is registered at ClinicalTrials.gov (NCT05596084).

The effect of autologous platelet concentrates as solely grafting material or with bone graft materials in maxillary sinus augmentation: a meta-analysis of randomized controlled trials

OBJECTIVES

This study compared the effectiveness of adding autologous platelet concentrates (APCs(+)) and sole bone grafting procedures (APCs(-)) in maxillary sinus augmentation (MSA).

MATERIALS AND METHODS

A systematic search was performed to identify randomized controlled trials (RCTs) from electronic database and clinical registers published up to June 1, 2024. Six evaluation indices comprising percentage of new bone formation (NBF%), percentage of residual bone substitute (RBS%), percentage of fibrous tissue (FT%), implant stability quotient (ISQ), bone height (BH) and bone density (BD) were identified.

RESULTS

We analyzed 14 studies involving 268 lifted sinuses and 119 implants. Compared with the APCs(-) group, the APCs(+) group demonstrated a significant advantage regarding NBF% (weight mean difference (MD)= 4.80, 95% confidence interval (CI) (1.82,8.32), p=0.007) and RBS% (MD=-4.48, 95% CI (-6.01,2.96), p<0.01), with no evident superiority in FT% (MD=-0.11, 95% CI (-0.56,0.35), p=0.64), ISQ (MD=-1.68, 95% CI (-6.77,3.40), p=0.52) and BH (standard mean difference (SMD) =-0.11, 95% CI (-3.04,2.83), p=0.94). While APCs(-) group showed a significant benefit in BD compared to the APCs(+) group (MD=-28.34, 95% CI (-48.98,-7.71), p=0.01).

CONCLUSION

Compared with APCs(-), APCs(+) could be a better option for promoting NBF% and reducing RBS%, whereas we found no evident influence in FT% and ISQ under MSA. Concerning BD and BH results, there were no additional effects with the addition of APCs, which needs to be treated with caution due to the limited number of studies.

CLINICAL RELEVANCE

APCs(+) procedures show promising results, with a higher NBF% and lower RBS%, making them a potential routine MSA strategy.

How to explain the beneficial effects of platelet-rich plasma

Platelet-rich plasma (PRP) is the platelet and leukocyte-containing plasmatic fraction of anticoagulated autologous blood. While evidence supporting the clinical use of PRP in dentistry is low, PRP is widely used in sports medicine, orthopedics, and dermatology. Its beneficial activity is commonly attributed to the growth factors released from platelets accumulating in PRP; however, evidence is indirect and not comprehensive. There is thus a demand to revisit PRP with respect to basic and translational science. This review is to (i) recapitulate protocols and tools to prepare PRP; (ii) to discuss the cellular and molecular composition of PRP with a focus on platelets, leukocytes, and the fibrin-rich extracellular matrix of coagulated plasma; and finally (iii) to discuss potential beneficial effects of PRP on a cellular and molecular level with an outlook on its current use in dentistry and other medical fields.

Effects of i-PRF, A-PRF+, and EMD on Osteogenic Potential of Osteoblasts on Titanium

OBJECTIVE

The study evaluates three biologically active substances with known bone-inductive potential on previously decontaminated titanium (Ti) discs.

MATERIAL AND METHODS

Rough and smooth Ti surfaces were contaminated with a multispecies biofilm and cleaned with a chitosan brush. Discs were treated either with injectable-platelet-rich fibrin (i-PRF), advanced platelet-rich fibrin (A-PRF+), or enamel matrix derivatives (EMDs) before osteoblast seeding.

RESULTS

Biocompatibility, adhesion, migration, and gene expression of runt-related transcription factor 2 (RUNX2), collagen Type I Alpha 2 (COL1a2), alkaline phosphatase (ALP), osteocalcin (OC), and osteonectin (ON) were performed. All the tested biologic agents similarly increased cell viability. Specifically, osteoblasts seeded over i-PRF and EMD-treated surfaces showed improvement in adhesion and migration and significantly increased ALP, OC, ON, RUNX-2, and COL1a2 mRNA levels up to 2.8 fold (p < 0.05) with no differences between Ti surfaces.

CONCLUSIONS

i-PRF and EMD possess beneficial bioactive properties that enhance tissue healing and promote regeneration on thoroughly sterilized surfaces. Biologically active materials may hold the potential to influence the process of implant re-osseointegration, which warrants more research since sterilization of the affected surfaces under clinical conditions is still not reliably possible and remains one of the greatest challenges.

APCs in sinus floor augmentation

After tooth loss in the posterior area of the maxilla, sinus floor elevation is often required to compensate the vertical bone loss due to sinus pneumatization. This narrative review reports on the potential benefits of autologous platelet concentrates (APCs) during this procedure. As for transcrestal approach, APCs have been used as "sole" substitute/graft. However, because of the low number of clinical trials available with PRGF, and even none for PRP, no definitive conclusions can be made regarding their efficacy. The number of studies on the use of L-PRF were outnumbered indicating good feasibility for vertical bone gain, with a high implant survival rate and a low degree of complications. PRP and PRGF have not been studied as a "single/sole" substitute for a one-stage lateral window approach, probably because of the weak physical characteristics of the membranes. L-PRF alone appears to be a predictable grafting material for lateral maxillary sinus grafting and a reduced RBH should not be considered as a risk factor. Compared to a "standard" bone substitute L-PRF shows slightly less vertical bone gain (consider enough membrane application and use of bony window as new sinus floor roof over the implant apices), enhanced early resorption (first 6 months after application), but a similar stable bone gain afterward. For a two-stage lateral window approach, APCs "alone" cannot be recommended, due to their weak withstand to the sinus pneumatization forces. APCs combined with bone substitutes seem to accelerate bone formation, without any additional benefits on the long-term new bone gain. The use of L-PRF membranes for the treatment of perforations appears to be an effective treatment option, but further clinical studies are needed to confirm this. Even though the abovementioned statements are based on large numbers of studies, additional RCTs comparing APCs with different types of grafting procedures for sinus elevation are needed.

Effectiveness of concentrated growth factors with or without grafting materials in maxillary sinus augmentation: a systematic review

Concentrated Growth Factor (CGF) is a highly effective biomaterial known for its ability to promote tissue regeneration. While it's been studied extensively in intraoral procedures and bone grafting, its benefits in maxillary sinus lifting lack substantial evidence. This review aimed to evaluate CGF's effectiveness in maxillary sinus augmentation, focusing on clinical, radiographic, and histological outcomes.A comprehensive literature search was conducted across PubMed, Scopus, Web of Science, Google Scholar, and Cochrane Library databases using specific mesh terms and keywords and adhered to PRISMA guidelines. Studies up to March 2024 involving transcrestal or lateral maxillary sinus floor elevation with CGF, either alone or in combination with grafting materials, were included.Out of 783 publications, 13 studies met the eligibility criteria. The review assessed CGF's role in minimizing postoperative complications, enhancing new bone formation, and improving implant survival. Despite data variability among studies, the majority reported that CGF positively influenced maxillary sinus augmentation outcomes.While more robust randomized clinical trials are required to draw definitive conclusions, initial results are promising, and the findings suggest that CGF utilization in maxillary sinus augmentation seems to enhance clinical outcomes by promoting vascularization and regeneration at the surgical sites and improving both the quality and quantity of newly formed sinus bone. Furthermore, it exhibits potential for improving postoperative sequelae and achieving high implant survival rates.

Repair of Schneiderian Membrane Perforation Through Membrane Fixation With Simultaneous Implant Placement: A Case Report

Perforation of the maxillary sinus membrane is a common complication during maxillary sinus elevation. Intraoperative perforation of the maxillary sinus membrane may complicate the procedure and indirectly lead to implant failure. Timely repair of the perforated maxillary sinus membrane can effectively improve the implant survival rate. This case describes a method of repairing a maxillary sinus membrane perforation with a suture-attached collagen membrane and shows stable repair results at a 31-month follow-up.

A Simplified GBR Treatment and Evaluation of Posterior Seibert Class I Ridge Defects via Bio-collagen and Platelet-Rich Fibrin: A Retrospective Study

BACKGROUND

Classical guided bone regeneration (GBR) treatments can achieve favorable clinical results for ridge defects. However, extensive bone augmentation in the non-esthetic area in the posterior region for minor ridge defects is unnecessary. Therefore, this study used a collagen and Platelet-rich fibrin (PRF) mixture for bone augmentation on minor posterior ridge defects and evaluated the effects.

METHODS

22 Seibert Class I ridge defects were treated with BC and covered with a PRF membrane (simplified guided bone regeneration, simplified GBR) and other 22 were treated with Bio-Oss and covered with Bio-Gide (classical GBR). Cone-beam computed tomography imaging was conducted 6 months post-surgery to compare the ridge's horizontal width (HW) and buccal ridge's horizontal width to assess the osteogenic effect. In addition, the buccal ridge contour morphology was studied and classified.

RESULTS

The buccal ridge contour of simplified GBR was Type A in 14 cases, Type B in 7 cases, and Type C in 1 case and it of classical GBR was Type A in 11 cases, Type B in 8 cases, and Type C in 3 cases. The mean HW significantly increased by 1.50 mm of simplified GBR treatment, while it increased by 1.83 mm in classical GBR treatment.

CONCLUSION

The combined use of BC and PRF had a significant effect on bone augmentation and this treatment exhibited promising clinical results for correcting posterior Seibert Class I ridge defects. The morphological classification of the reconstructive effect in this study can be utilized in future clinical work.

Sinus Floor Augmentation with Synthetic Hydroxyapatite (NanoBone®) in Combination with Platelet-Rich Fibrin: A Case Series

Several techniques have been described for maxillary sinus graft augmentation, including the lateral window technique and crestal approach with osteotomes or osseodensification. Platelet-rich fibrin has been used in maxillary sinus lift procedures due to its ability to accelerate soft and hard tissue healing. The aim of this study was to evaluate the potential of PRF in combination with the synthetic hydroxyapatite NanoBone® to enhance bone regeneration in sinus floor elevation with the lateral window technique. Out of the 50 individuals screened in a preoperative assessment visit from the CESPU-Famalicão clinical unit and intervened upon between January 2023 and December 2023, only 6 patients who met the study's inclusion criteria consented to participate. In a split-mouth study, twelve sinus graft surgeries were carried out. Our observations reveal that for the test group (NanoBone®/PRF), there is a 27.5 ± 4.9% increase new vital bone, 23.0 ± 3.7% increase in inert bone particles, and 49.4 ± 2.8% increase in connective tissue. Meanwhile, for the control group (NanoBone®), there is a 19.5 ± 3.0% increase in new vital bone, 23.4 ± 5.7% increase in inert bone particles, and 57.0 ± 3.5% increase in connective tissue. The results strongly indicate that mixing liquid PRF with NanoBone® does not have a negative influence on the amount of viable bone formation, and it seems to slightly increase the amount of new bone formation and revascularization in sinus bone graft procedures with the lateral window technique compared to the single use of NanoBone®.

Effectiveness of Autologous Platelet Concentrates in the Sinus Lift Surgery: Findings from Systematic Reviews and Meta-Analyses

Maxillary sinus augmentation is one of the most predictable procedures for the rehabilitation of the posterior maxilla. The current overview aimed to summarize the findings provided by systematic reviews (SRs) and meta-analyses on the effectiveness of autologous platelet concentrates (APCs) in sinus lift and to assess the methodological quality of the included SRs. Three electronic databases have been explored. SRs and meta-analyses addressing the effectiveness of APCs in sinus lift technique were included. Clinical, radiographic and histomorphometric findings were considered for APCs as solely grafting materials and APCs in combination with biomaterials. Outcomes were implant survival rate (ISR), implant stability (IS), implant failure (IF), postoperative complications, histomorphometric findings, radiographic bone gain, bone volume and bone density. The methodological quality of the included SRs was assessed using the updated version of "A Measurement Tool to Assess Systematic Review" (AMSTAR-2). Thirty SRs were included. The methodological quality of the included reviews ranged from critically low (3 studies) to high (9 studies). The included SRs showed favorable clinical outcomes, short-term new bone formation and no biological complications when APCs were used both as solely graft material or in combination with other biomaterials. However, no significant additional effects in the long-term period were observed. APCs did not add any further positive effects compared to the physiological healing derived by the natural blood clot. The current overview of SRs highlighted the need for high-quality SRs evaluating the role of APCs in sinus lift though network meta-analyses, in order to identify the most powerful material for sinus lift augmentation. The use of APCs improves the healing of soft tissues and the postoperative quality of life in the short-term period. Thus, its application can be recommended.

Potentials of pure xenograft materials in maxillary ridge augmentation: A case series

Many patients require edentulous ridge augmentation for dental implant placement. The main objective of this study was to evaluate the results of maxillary edentulous ridge augmentation exclusively with xenograft materials with and without simultaneous sinus floor elevation. This study reports the data retrieved from the records of 16 patients. The treatment outcome was assessed at least 6 months, postoperatively. Paired samples t-test or Wilcoxon Signed Rank test was used to compare the pre-and postoperative ridge dimensions. Dental implants were placed simultaneously in 7 patients, while 9 patients underwent delayed implant placement. In total, 68 implants were placed, and 12 patients also underwent maxillary sinus floor augmentation. A significant bone gain was achieved in both horizontal and vertical dimensions of edentulous maxillary ridges (P < 0.001). Ridge width increased by an average of 4.35 ± 1.90 mm (95% CI: 3.84 to 4.85 mm) while ridge height in areas of sinus floor augmentation increased by 8.19 ± 2.91 mm (95% CI: 7.33 to 9.05 mm). Within the study limitations, it appears that maxillary ridge augmentation according to the guided bone regeneration (GBR) protocols with exclusive use of xenograft particulate materials can provide optimal bone quantity for dental implant placement.

Maxillary Sinus Lift Procedures: An Overview of Current Techniques, Presurgical Evaluation, and Complications

A maxillary sinus lift procedure is indicated if a dental implant needs to be placed in the posterior maxilla with limited bone available to accommodate a dental implant. Both open and closed sinus lifting procedures are reliable approaches for increasing the bone volume needed to support proper implant positioning. However, these methods can lead to several complications. In addition to the general complications commonly linked to oral surgery, such as swelling or hematoma, the primary complication in open sinus lifting is typically the perforation of the Schneiderian membrane during osteotomy. Detailed and extensive presurgical evaluation is crucial to minimize such complications. The objective of this study was to delineate contemporary trends in sinus lift surgery, with a specific emphasis on different techniques of sinus lift procedure, anatomical and surgical factors, presurgical evaluation, bone grafting, and the practical implications of these factors in implant dentistry cases involving a deficient posterior maxilla. In conclusion, while both osteotome and lateral window techniques can assist clinicians in addressing the complexities of implant placement in a deficient posterior maxilla, bone height before implantation remains a critical factor in determining the success and longevity of implants.

Proteomic Analysis of Mesenchymal Stromal Cells Secretome in Comparison to Leukocyte- and Platelet-Rich Fibrin

Secretomes of mesenchymal stromal cells (MSCs) are emerging as a novel growth factor (GF)-based strategy for periodontal and bone regeneration. The objective of this study was to compare the secretome of human bone marrow MSC (BMSC) to that of leukocyte- and platelet-rich fibrin (L-PRF), an established GF-based therapy, in the context of wound healing and regeneration. Conditioned media from human BMSCs (BMSC-CM) and L-PRF (LPRF-CM) were subjected to quantitative proteomic analysis using liquid chromatography with tandem mass spectrometry. Global profiles, gene ontology (GO) categories, differentially expressed proteins (DEPs), and gene set enrichment (GSEA) were identified using bioinformatic methods. Concentrations of selected proteins were determined using a multiplex immunoassay. Among the proteins identified in BMSC-CM (2157 proteins) and LPRF-CM (1420 proteins), 1283 proteins were common. GO analysis revealed similarities between the groups in terms of biological processes (cellular organization, protein metabolism) and molecular functions (cellular/protein-binding). Notably, more DEPs were identified in BMSC-CM (n = 550) compared to LPRF-CM (n = 118); these included several key GF, cytokines, and extracellular matrix (ECM) proteins involved in wound healing. GSEA revealed enrichment of ECM (especially bone ECM)-related processes in BMSC-CM and immune-related processes in LPRF-CM. Similar trends for intergroup differences in protein detection were observed in the multiplex analysis. Thus, the secretome of BMSC is enriched for proteins/processes relevant for periodontal and bone regeneration. The in vivo efficacy of this therapy should be evaluated in future studies.

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.

The Effectiveness of the Addition of Platelet-Rich Fibrin to Bovine Xenografts in Sinus and Bone Ridge Augmentation: A Systematic Review

Dental implants sometimes need bone augmentation to recreate an adequate bone height and volume. Numerous bone augmentation techniques have been described, and, currently, the most commonly used bone graft procedure is xenografts with deproteinized bovine bone mineral (DBBM). The addition of platelet-rich fibrin (PRF) to DBBM has already shown better performance than DBBM alone in restoring intrabony periodontal defects, but the role of PRF in preimplantation bone grafts is still not clear. The objective of this systematic review was to evaluate the efficacy of the adjunction of PRF or L-PRF to DBBM in bone ridge augmentation procedures. Clinical randomized controlled studies using PRF associated with DBBM were included. In April 2023, three electronic databases (PubMed, Cochrane, and Web of Science) were searched. The search strategy was performed according to PRISMA guidelines. The risk of bias assessments were performed using the Cochrane Collaboration tool. A total of seven articles were included and analyzed. The results show no statistically significant effect of PRF added to DBBM compared to DBBM alone in the sinus lift procedure but do show an effect in the reduction in bone graft resorption in one study of mandibular guided bone regeneration.

Clinical Research on the Safety Evaluation of Platelet-rich Plasma Treatment in Oral Diseases: A Study Protocol

Background

Platelet-rich plasma (PRP) is a biological product obtained from autologous blood that contains growth factors, promoting the healing and regeneration of human tissues. Several oral diseases require surgical intervention, producing residual wounds that undergo a healing process, accompanied by pain, swelling, superinfections, and bone remodeling. This protocol study aims to evaluate the safety of PRP use for the following dental procedures: post-extraction socket healing, periodontal tissue regeneration, maxillary sinus floor elevation, tooth transplantation, and intentional tooth replantation.

Methods

Ten patients will be enrolled and subjected to the required treatment with the addition of PRP, after appropriate hematological and biochemical evaluations. The participants will then be subjected to an observation period of 4 weeks to monitor adverse events through clinical observation. Secondary outcomes will regard pain, and clinical evolution of the treated site. Among these, presence of infection, swelling, wound healing, stability of the transplanted tooth.

Discussion

Safety of medical procedures represents the first requirement for their introduction in routine practice. A careful evaluation of clinical response during follow-up period and registration of adverse effects is fundamental for safety confirmation and subsequent use of PRP for the proposed dental procedures.

Trial registration

Japan Registry of Clinical Trials (https://jrct.niph.go.jp/, registry number: jRCTc030190273, jRCTc030190274, jRCTc030190275, jRCTc030190276, jRCTc030190277; Date of registration: 31 March 2020).

Recent progress and clinical applications of advanced biomaterials in cosmetic surgery

Materials of different allogeneic or xenogeneic or autologous origins are widely used as soft-tissue fillers or structural scaffolds in the field of cosmetic surgery, while complications including prosthesis infection, donor site deformity and filler embolization have always been difficult problems for plastic surgeons. The application of novel biomaterials may bring in hopeful solutions for these problems. Recently, some advanced biomaterials, such as regenerative biomaterials can effectively promote the repair of defective tissues, which have been proven to have good therapeutic as well as cosmetic effects in cosmetic surgery. Therefore, biomaterials with active compounds have drawn significant attention for the tissue regeneration of reconstructive and esthetic treatment. Some of these applications have achieved better clinical outcomes than traditional biological materials. This review summarized recent progress and clinical applications of advanced biomaterials in cosmetic surgery.

Efficacy of biologics for alveolar ridge preservation/reconstruction and implant site development: An American Academy of Periodontology best evidence systematic review

BACKGROUND

The use of biologics may be indicated for alveolar ridge preservation (ARP) and reconstruction (ARR), and implant site development (ISD). The present systematic review aimed to analyze the effect of autologous blood-derived products (ABPs), enamel matrix derivative (EMD), recombinant human platelet-derived growth factor-BB (rhPDGF-BB), and recombinant human bone morphogenetic protein-2 (rhBMP-2), on the outcomes of ARP/ARR and ISD therapy (i.e., alveolar ridge augmentation [ARA] and maxillary sinus floor augmentation [MSFA]).

METHODS

An electronic search for eligible articles published from January 2000 to October 2021 was conducted. Randomized clinical trials evaluating the efficacy of ABPs, EMD, rhBMP-2, and rhPDGF-BB for ARP/ARR and ISD were included according to pre-established eligibility criteria. Data on linear and volumetric dimensional changes, histomorphometric findings, and a variety of secondary outcomes (i.e., clinical, implant-related, digital imaging, safety, and patient-reported outcome measures [PROMs]) were extracted and critically analyzed. Risk of bias assessment of the selected investigations was also conducted.

RESULTS

A total of 39 articles were included and analyzed qualitatively. Due to the high level of heterogeneity across studies, quantitative analyses were not feasible. Most studies in the topic of ARP/ARR revealed that the use of biologics rendered similar results compared with conventional protocols. However, when juxtaposed to unassisted healing or socket filling using collagen sponges, the application of biologics did contribute to attenuate post-extraction alveolar ridge atrophy in most investigations. Additionally, histomorphometric outcomes were positively influenced by the application of biologics. The use of biologics in ARA interventions did not yield superior clinical or radiographic outcomes compared with control therapies. Nevertheless, ABPs enhanced new bone formation and reduced the likelihood of early wound dehiscence. The use of biologics in MSFA interventions did not translate into superior clinical or radiographic outcomes. It was observed, though, that the use of some biologics may promote bone formation during earlier stages of healing. Only four clinical investigations evaluated PROMs and reported a modest beneficial impact of the use of biologics on pain and swelling. No severe adverse events in association with the use of the biologics evaluated in this systematic review were noted.

CONCLUSIONS

Outcomes of therapy after post-extraction ARP/ARR and ARA in edentulous ridges were comparable among different therapeutic modalities evaluated in this systematic review. Nevertheless, the use of biologics (i.e., PRF, EMD, rhPDGF-BB, and rhBMP-2) in combination with a bone graft material generally results into superior histomorphometric outcomes and faster wound healing compared with control groups.

The application of leukocyte- and platelet-rich fibrin (L-PRF) in maxillary sinus augmentation

BACKGROUND

Since the introduction of sinus augmentation in the 1970s the procedure has been performed with or without biomaterials. Autologous blood products (ABPs) for use in sinus augmentation was first introduced in the 2000s, to aid potentially in bone and soft tissue healing.

METHODS

Three different applications of leukocyte- and platelet-rich fibrin (L-PRF) in maxillary sinus augmentation are presented in this case series. In case 1, L-PRF is used in bilateral sinus augmentation to support placement of implants to support a maxillary hybrid denture. Case 2 highlights the use of L-PRF in a complication associate with Schneiderian membrane elevation. Case 3 provides histology taken at the time of implant placement 6 months following L-PRF/xenograft sinus augmentation.

RESULTS

All cases resulted in the successful placement of dental implants. In case 2, an osseodensification procedure was performed with freeze-dried bone allograft, which provided an approximate 4 mm of additional vertical height for implant placement. Histology from case 3 at 6 months post sinus augmentation demonstrated the presence of new vital bone in contact with the xenograft.

CONCLUSION

To date, there is only a limited amount of evidence reporting on platelet-rich fibrin (PRF) or L-PRF use in maxillary sinus augmentation. Bone gain from either product has ranged from 3.2 to 11.8 mm, with the percentage of newly formed bone reported in case series as 33% ± 5%. Despite the lack of strong evidence, L-PRF appears to have beneficial effects on bone regeneration when used in sinus augmentation.

Application Effect of External and Internal Elevation of Maxillary Sinus in Implant Restoration of Posterior Maxilla

Objective

To explore and analyze the application effect of external and internal elevation of the maxillary sinus in implant restoration of the posterior maxilla.

Methods

A total of 84 patients undergoing implant restoration of the posterior maxilla in the hospital were enrolled between January 2019 and March 2021. According to the random number table method, they were divided into the observation group (n = 42) and the control group (n = 42). The control group underwent external elevation of the maxillary sinus, while the observation group underwent internal elevation of the maxillary sinus. At 6 h, 12 h, and 24 h after surgery, the pain degree between the two groups was compared. All were followed up at 6 months after surgery. The osseointegration (bone resorption around implants, elevation height of maxillary sinus floor, average healing time) and soft tissues (bleeding index, plaque index, probing depth) in both groups were observed. The occurrence of postoperative complications was recorded.

Results

At 6 h, 12 h, and 24 h after surgery, VAS scores in the observation group were significantly lower than those in the control group (P < 0.05). At 6 months after surgery, bone resorption and elevation height of the maxillary sinus floor in the observation group were significantly higher than those i.0.0n the control group, and the average healing time was significantly shorter than that in the control group (P < 0.05). The bleeding index, plaque index, and probing depth in the observation group were significantly lower than those in the control group (P < 0.05). There was no significant difference in the incidence of postoperative complications between the observation group and the control group (9.52% vs. 19.05%) (P > 0.05).

Conclusion

The application effect of internal elevation of the maxillary sinus is good in implant restoration of the posterior maxilla, which can relieve pain and swelling and improve implant effect.

Effect of Sinus Floor Augmentation with Platelet-Rich Fibrin Versus Allogeneic Bone Graft on Stability of One-Stage Dental Implants: A Split-Mouth Randomized Clinical Trial

Rehabilitation of an edentulous posterior maxilla with dental implants is challenging, and sinus floor augmentation could be considered as an important surgical procedure for bone augmentation in this region before implant placement. Platelet-rich fibrin (PRF) is a new-generation platelet concentrate with simplified processing: its application in sinus floor augmentation has been widely investigated in literature. However, the biological properties and actual efficacy of this product remain controversial. This study assessed the effect of sinus floor augmentation with PRF versus freeze-dried bone allograft (FDBA) on stability of one-stage dental implants. This split-mouth randomized clinical trial evaluated 10 patients who required bilateral sinus floor augmentation. PRF and L-PRF membrane were used in one quadrant while FDBA and collagen membrane were used in the other quadrant. Implant stability was assessed by resonance frequency analysis (RFA) immediately, and 2, 4, and 6 months after implant placement. The implant stability quotient (ISQ) was compared over time and between the two groups using repeated measures ANOVA and independent sample t-test. The mean ISQ significantly increased over time in both groups (p < 0.001). The increase was greater in the PRF group (p < 0.05). Within the limitations of this study, PRF yielded superior results compared with FDBA regarding the stability of one-stage dental implants.

Platelet-rich plasma alone is unable to trigger contact osteogenesis on titanium implant surfaces

PURPOSE

Osseointegration consists of bidirectional bone formation around modified implant surfaces by contact osteogenesis and distance osteogenesis. This study tested whether contact osteogenesis on the surface of a modified titanium (Ti) implant is stimulated by cytokines in the blood.

METHODS

In the first two types of experiments, sandblasted, large-grit, acid-etched Ti implants and turned Ti tubes were inserted into rabbit tibiae. To exclude the influence of distance osteogenesis, the tubes were inserted into the tibiae, and implants were placed inside the tubes. In a third type of experiment, the implants and tubes were inserted into the rabbit tibiae, and platelet-rich plasma (PRP) or recombinant human bone morphogenetic protein-2 (rhBMP-2) was applied topically. Four weeks after implantation, undecalcified specimens were prepared for histomorphometry. Bone-to-implant contact (BIC) and bone area per tissue (BA) were measured, and the data were analysed using one-way ANOVA at a significance level of 0.05.

RESULTS

When the response of bone to Ti tubes with implants was compared to that without implants (first experiment), little bone formation was found inside the tubes. The mean BIC of implant specimens inside the tubes was 21.41 ± 13.81% in a second experiment that evaluated bone responses to implants with or without Ti tubes. This mean BIC value was significantly lower than that in the implant-only group (without tubes) (47.32 ± 12.09%, P = 0.030). The third experiment showed that rhBMP-2 significantly increased contact osteogenesis on the implant surface, whereas PRP had no effect (mean BIC: 66.53 ± 14.06% vs. 16.34 ± 15.98%, P = 0.004).

CONCLUSIONS

Platelet-rich plasma alone is unable to trigger contact osteogenesis on the modified titanium implant surface.

Platelet concentrates in periodontics: review of in vivo studies and systematic reviews

Clot formation is the first step of the healing process, and clinical procedures always find ways to stabilize this clot better. Platelets play a significant role in clot formation, and Platelet Concentrates (Pc) are an abundant reservoir of platelets. This article aims to review the in vitro research and systematic reviews on PCs that are currently available. Broadly, PCs mainly include Platelet-rich plasma and platelet-rich fibrin. PCs are an excellent source for growth factors such as PDGF-AA, TGF β1, VEGF, EGF, and IGF. Numerous systematic reviews and meta-analyses have analyzed the clinical application of PCs in various periodontal procedures. In alveolar ridge preservation, PCs are known to reduce postoperative pain, edema, trismus, and inflammation. PRF had shown significant improvement in achieving root coverage and recession depth reduction. PCs exhibited a positive influence on CAL gain when used as an adjunct to OFD in treating infra-bony defects. Pcs have a positive effect on bone maturation in the short term. Besides, PCs can be used in regenerative endodontics, treatment of medication-related osteoradionecrosis of Jaw (MRONJ), and accelerating tooth movement. In conclusion, PCs positively affect soft tissue healing, while their role in hard tissue healing is still unclear.

Application of platelet-rich fibrin on mandibular third molar extraction: systematic review and Meta-analysis

OBJECTIVES

This study aims to analyze the effectiveness of platelet-rich fibrin (PRF) in mandibular third molar extraction and provide suggestions for alleviating postoperative complications.

METHODS

Pubmed, EMBASE, Web of Science, and SinoMed were searched electronically on February 2020. Randomized controlled trials focusing on PRF usage in mandibular third molar extraction were included. Reviewers assessed the risk of bias in the included literature and extracted data independently using the criteria recommended by the Cochrane Collaboration. Meta-analysis was performed using RevMan 5.3 and STATA 13.0.

RESULTS

Twenty-one studies were included, comprising 991 patients who had mandibular third molar extraction. The topical application of PRF effectively reduced pain after extraction [MD=-12.06, 95%CI (-21.42, -2.71), P=0.01], attenuated post-extraction swelling [MD=-1.42, 95%CI (-2.41, -0.44), P=0.005], and promoted soft tissue hea-ling [MD=0.66, 95%CI (0.34, 0.99), P<0.000 1]. PRF significantly reduced trismus and alveolar osteitis (P<0.05). However, data could not prove whether PRF has any significant positive effect on bone healing compared with the control group (P>0.05).

CONCLUSIONS

Limited clinical evidence indicates that applying PRF after mandibular third molar extraction could reduce pain, swelling, trismus and the occurrence of dry socket and promote soft tissue healing. However, the effect of PRF on bone healing requires further large-scale randomized controlled trials and unified measurement criteria.

Platelet lysate: a promising candidate in regenerative medicine

Human platelet lysate has attracted much interest from many researchers as it is growth-factor rich for cell expansion, which is employed as a new therapeutic strategy. Not only are human platelet lysates used for cell therapy, but they are also used for the completion of basal media in mesenchymal stem cell cultures. Due to the presence of a large number of growth factors, platelet lysates have potential roles in wound healing, treatment of ocular graft-versus-host disease, osteoarthritis, Parkinson's disease, tendon regeneration, infertility, androgenetic alopecia, nerve repair and regenerative tissue, such as bone regeneration. In this review, we summarize that platelet lysates could be valuable candidates for the treatment of a variety of diseases in regenerative medicine.

Implant Placement Following Crestal Sinus Lift with Sequential Drills and Osteotomes: Five Years after Final Loading Results from a Retrospective Study

The aim of this retrospective study was to clinically evaluate the five-year outcomes of implants placed following a combined approach to the sinus, consisting of sequential drills and osteotomes. Medical records of patients with implants placed in combination with crestal sinus lift using sequential drills and osteotomes, with a residual alveolar bone crest between 4 to 8 mm, and a follow-up of at least five years after final loading, were evaluated. Outcomes were implant and prosthetic survival and success rates, any complication, and marginal bone loss. Data from 96 patients (53 women and 43 men; mean age 54.7 years; range 23-79 years) were collected. A total of 105 single implants were analyzed. After five years of function, two implants were lost and two prostheses failed. No major biological or prosthetic complications occurred. At the five-year examination, the marginal bone loss was 1.24 ± 0.28 mm. Within the limitations of this retrospective study it can be concluded that implants placed following a combined approach to the sinus consisting of sequential drills and osteotomes seem to be a viable option for the treatment of posterior atrophic edentulous maxilla.

PRP in wound healing applications

Platelets play a crucial role in hemostasis, tissue regeneration and host defense. Based on these settings, platelet-rich plasma (PRP) and its derivatives are therapeutically used to promote wound healing in several scenarios. This review summarizes the biological mechanisms underlying the most traditional as well as innovative applications of PRP in wound healing. These mechanisms involve the combined action of platelet-derived growth factors and cytokines, together with the role of plasma-derived fibrillar, antioxidant and homeostatic factors. In addition, regenerative treatments with PRP consist of personalized and non-standardized methods. Thus, the quality of PRP varies depending on endogenous factors (e.g., age; gender; concomitant medication; disease-associated systemic factors; nutrition) and exogenous factors (anticoagulants and cellular composition). This review also analyses whether these factors affect the biological mechanisms of PRP in wound healing applications.

Evidence-Based Clinical Efficacy of Leukocyte and Platelet-Rich Fibrin in Maxillary Sinus Floor Lift, Graft and Surgical Augmentation Procedures

Bone augmentation techniques have increasingly been indicated for re-creating adequate bone height and volume suitable for dental implant sites. This is particularly applicable in the severely atrophic posterior maxilla where sinus perforation (ruptured Schneiderian membrane) is a very common complication and sinus floor elevation or lift is frequently considered a standard procedure. The augmentation of the maxillary sinus can be performed with or without grafting biomaterials. Herein, numerous biomaterials and bone substitutes have been proposed, primarily to sustain the lifted space. In addition, cytokines and growth factors have been used to stimulate angiogenesis, enhance bone formation as well as improve healing and recovery period, either as the sole filling material or in combination with bone substitute materials. Within such, is the family of autologous blood extracts, so-called platelet concentrates, which are simply the "product" resulting from the simple centrifugation of collected whole blood samples of the patient, immediately pre-surgery. Platelet-Rich Fibrin (PRF), a sub-family of platelet concentrates, is a three-dimensional (3-D) autogenous biomaterial obtained, without including anti-coagulants, bovine thrombin, additives, or any gelifying agents during the centrifugation process. Today, it is safe to say that, in implant dentistry and oral and maxillofacial surgery, PRFs (particularly, the pure platelet-rich fibrin or P-PRF and leukocyte and platelet-rich fibrin or L-PRF sub-classes) are receiving the most attention, essentially due to their simplicity, rapidness, user-friendliness/malleability, and cost-effectiveness. Whether used as the sole "bioactive" filling/additive material or combined with bone substitutes, the revolutionary second-generation PRFs have been very often associated with promising clinical results. Hence, this review aims to provide a 10-years update on the clinical effectiveness of L-PRF when applied/used as the "sole" biomaterial in maxillary sinus augmentation procedures. An electronic search using specific keywords for L-PRF and maxillary sinus augmentation was conducted in three main databases (PubMed-MEDLINE database, Google Scholar and Cochrane library) for the period between January 2009-February 2020. The quest yielded a total of 468 articles. Based on the pre-established strict inclusion/exclusion criteria, only seven articles were deemed eligible and included in the analysis. Surprisingly, of the 5 studies which used de-proteinized bovine bone mineral (DBBM) in combination with L-PRF, 60% acclaimed no significant effects and only 40% declared positive effects. Of the two articles which had used allogenous bone graft, 50% declared no significant effects and 50% acclaimed positive effects. Only one study had used L-PRF as the sole grafting material and reported a positive effect. Likewise, positive effects were reported in one other study using L-PRF in combination with a collagen membrane. Due to the heterogeneity of the included studies, this review is limited by the inability to perform a proper systematic meta-analysis. Overall, most of the published studies reported impressive results of L-PRF application as a grafting material (sole or adjuvant) in maxillary sinus augmentation and dental implant restorative procedures. Yet, distinct technical processing for L-PRF preparation was noted. Hence, studies should be approached with caution. Here in, in sinus lift and treatment of Schneider membrane, the formation of mature bone remains inconclusive. More studies are eagerly awaited in order to prove the beneficial or detrimental effects of PRFs, in general and L-PRFs, in specific; especially in their tissue regenerative potential pertaining to the promotion of angiogenesis, enhancing of cell proliferation, stimulation of cell migration and autocrine/paracrine secretion of growth factors, as well as to reach a consensus or a conclusive and distinct determination of the effect of leukocytes (and their inclusion) on inflammation or edema and pain; a call for standardization in PRFs and L-PRFs composition reporting and regimenting the preparation protocols.

Update on Maxillary Sinus Augmentation

Implant stability is critical to implant success, and the amount of available bone is vital to achieving that end. Because of low-lying maxillary sinuses, adequate alveolar height on the posterior maxilla is often lacking in many patients in need of implant replacement. This chapter reviews both the traditional lateral sinus lift maxillary approach to achieve vertical augmentation as well as the transcrestal osteotome intraoral approach. A discussion of osseodensification will also be mentioned as an alternative approach.

The Effect of Autologous Platelet Concentrates on Maxillary Sinus Augmentation: A Meta-Analysis of Randomized Controlled Trials and Systematic Review

INTRODUCTION

To assess the efficacy of the autologous platelet concentrates (APCs) combined with autologous bone or bone substitute for the maxillary sinus floor lifting by a meta-analysis.

MATERIALS AND METHODS

Electronic databases (PUBMED, Web of Science, EMBASE through OVID, and Cochrane Library) were searched until Dec 31, 2019, and only randomized controlled trials (RCTs) in English were identified. Outcome variables included histologic evaluation, the implant stability quotient values, and radiographic evaluation. Data were analyzed by Revman5.3; the estimate of effect sizes was expressed as the 95% confidence interval; and the risk of bias was evaluated using the Cochrane Collaboration tool.

RESULTS

11 RCTs involving 141 patients (214 sites) were included in our meta-analysis, which indicated that the differences in the percentage of contact length among newly formed bone (2.61%, 95% CI, -1.18% to 7.09%), soft tissue area (-0.15%, 95% CI, -0.54% to 0.24%), and residual bone substitute material (-5.10%, 95% CI, -10.56% to 0.36%) in the APC group lacked statistical significance. Besides, there was the same effect on the implant stability quotient (ISQ) values of APC group who underwent implant placement 4 months after sinus augmentation and control group who received implant placement 8 months after sinus augmentation (-0.48, 95% CI, -1.68 to 0.72). No significant effect of APCs on the bone density was found (1.05%, 95% CI, -1.69% to 3.82%).

CONCLUSIONS

The use of APCs in sinus augmentation may be further shorten the time required for bone graft maturation and allow earlier implant placement, but cannot enhance the bone formation in the long term. It is not currently recommended for routine use APCs as an osteoinductive material to bone grafting in sinus augmentation.