Guided bone regeneration in staged vertical and horizontal bone augmentation using platelet-rich fibrin associated with bone grafts: a retrospective clinical study

Horizontal ridge augmentation through ridge expansion via osseodensification, guided bone regeneration and ridge‑split: Systematic review and meta‑analysis of clinical trials

The aim of the present systematic review was to compare three ridge augmentation procedures in order to assist clinicians in finding the ideal surgical method relative to the horizontal bone gain needed and the width of the alveolar ridge available. An electronic and hand literature search was performed in the online databases PubMed-Medline, Cochrane Central Register of Controlled Trials, EMBASE, Cochrane Oral Health Group Trials Register and Web of Science, and various specialized journals, between January 2017 and December 2022. The included studies were evaluated using the Methodological Index for Non-randomized Studies score and Cochrane's RoB tool. The primary variable studied in the meta-analysis was the final bone gain. The implant survival rate and initial ridge width were the secondary variables. Then four studies on ridge expansion via osseodensification (OD), seven on guided bone regeneration (GBR) and seven on the ridge-split technique (RS) were included in the review; 17 out of 18 were selected for meta-analysis. The mean horizontal bone gain for OD was 2.151 mm [1.327-2.975 mm; 95% confidence interval (CI)], for GBR was 4.036 mm (3.351-4.772 mm 95%CI) and for RS was 3.661 mm (2.991-4.399 mm 95%CI). The results were statistically significant (P=0.002). GBR reported the most bone gain horizontally, followed closely by RS and then OD. OD is a recent technique that should be taken into account when discussing the protocols of horizontally atrophied ridge rehabilitation.

A narrative review on the use of autologous platelet concentrates during alveolar bone augmentation: Horizontal (simultaneous/staged) & vertical (simultaneous/staged)

This review aimed to answer the general question of whether autologous platelet concentrates (APCs, an autologous blood-derivative) can improve the outcome of alveolar bone augmentation. Three clinical scenarios were assessed: horizontal/vertical bone augmentation in combination with implant placement (simultaneous approach), horizontal bone augmentation in a staged approach, and vertical bone augmentation in a staged approach. An electronic literature search strategy was conducted for each review from the outset to July 1st, 2023. The titles and abstracts (when available) of all identified studies were screened and imported into a database. If articles appeared to meet the inclusion criteria or their title and abstract had insufficient data, the full text was obtained to make the final decision. All studies that met the inclusion criteria underwent data extraction. Moreover, the references of the identified papers were screened for additional studies. After title and abstract screening and selection criteria application, 14 clinical studies were included for the qualitative analysis: seven for horizontal/vertical bone augmentation in a simultaneous approach, five for horizontal bone augmentation in a staged approach, and two for vertical bone augmentation in a staged approach. There is scarce literature regarding the added value of APCs in bone augmentation, and most studies had small sample sizes, a lack of standardized protocols, and different outcome variables, which makes comparisons between studies difficult. Out of the 14 studies, four were well-designed randomized clinical trials, where we could find better results for the APCs groups. Most studies, particularly comparative and well-designed studies, demonstrated beneficial and promising results of using APCs in alveolar bone augmentation. However, before high-level evidence-based conclusions can be drawn, more randomized clinical trials must compare the benefits of adding APCs to the gold-standard approach.

The effect of injectable platelet-rich fibrin in combination with autogenous bone grafts on bone healing in an ovariectomized osteoporotic rat model with critical-sized defects

OBJECTIVES

To assess the impact of autogenous graft materials, including autogenous bone graft (ABG) and injectable platelet-rich fibrin (I-PRF) clots, on bone defect regeneration in ovariectomized osteoporotic rats.

METHODS

Wistar rats (6-8 weeks old) were ovariectomized, and surgery began after 8 weeks. A 5-mm defect was created bilaterally in the parietal bones of 16 rats, which were divided into 4 groups. Group A (blank) had untreated defects; group B had defects filled with 0.1 ml of I-PRF, group C had defects filled with 0.1 ml of ABG, and group D had defects filled with a combination of 0.1 ml each of I-PRF and ABG. Four weeks post-surgery, the rats were euthanized. Bone regeneration was evaluated through histopathologic analysis and microcomputed tomography (micro-CT).

RESULTS

In ovariectomized rats treated with ABG or I-PRF, bone regeneration was enhanced, with increased periosteal activity, osteoblast count, and new bone volume, as determined histologically. The ABG+I-PRF group had the highest periosteal vascularity, but the difference compared to the ABG group was not statistically significant (p>0.05). Osteoblast numbers were significantly higher in the ABG+I-PRF group than in the blank group (p<0.05). Micro-CT showed the highest mean new bone volume ratio in the ABG+I-PRF group, followed by the ABG group.

CONCLUSION

The combined use of ABG and I-PRF enhances bone formation in osteoporotic rats following ovariectomy.

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.

Non-surgical and guided-bone-regeneration surgical management of Type-3b dens invaginatus with an apico-marginal defect: A case report

BACKGROUND

Dens invaginatus (DI), an unusual developmental anomaly is a challenge for the operating dentist with regard to its diagnosis and treatment. This case report presents the successful management of a Type-3b DI in a permanent maxillary lateral incisor associated with a large radicular cyst and communicating apico-marginal defect (Von Arx type IIb).

METHODS AND RESULTS

A 19-year-old female patient reported pain and palatal swelling. During the clinical examination, tooth #12 exhibited tenderness to percussion, and presented a deep periodontal pocket depth (PPD) of 12 mm, along with grade I mobility. Radiographic examination revealed a large peri-radicular radiolucency with atypical tooth morphology. Cone beam computed tomography clarified the complicated root canal anatomy to be Type-3b DI associated with an apico-marginal defect. The case was managed successfully by non-surgical endodontic therapy followed by surgical intervention utilizing a guided bone regenerative (GBR) approach. Eighteen-month follow-up showed an asymptomatic and functional tooth with a significant reduction in pocket depth. The periapical radiographs showed continued healing of the osseous defect.

CONCLUSIONS

The successful healing outcome of a challenging case, characterized by a complex DI morphology, a large peri-radicular lesion, a through-and-through defect, and a combined endodontic-periodontal apico-marginal defect was achieved through accurate diagnosis, treatment planning, and execution using contemporary endodontic and periodontal treatment techniques. The application of GBR techniques during the surgical phase of treatment may have contributed to the improved regenerative healing outcome in this case, which was initially considered prognostically questionable.

KEY POINTS

Why is this case new information? Type-3b DI exhibits a complex root canal structure, each case displaying unique characteristics, necessitating a case-specific treatment plan. In this case report the Type-3b DI morphology was associated with a large peri-radicular, through and through defect and combined endodontic periodontal apico-marginal defect. The treatment approach involved incorporating guided bone regenerative (GBR) principles during the surgical phase. This case report contributes to the existing evidence on the diagnosis and successful management of Type-3b DI with a concurrent apico-marginal defect. What are the keys to successful management of this case? The successful management of a prognostically challenging case was achieved through a closely integrated multidisciplinary coordination between the endodontist and periodontist. Utilization of contemporary techniques and tools contributed to the successful management The use of three-dimensional radiological examination through cone beam computed tomography enabled a precise preoperative assessment, facilitating the formulation of a treatment plan for managing both the Type-3b DI morphology and the associated peri-radicular lesion. Employing GBR techniques in peri-radicular surgery may have assisted in the healing of through-and-through periapical defects with concurrent apico-marginal defects (Von Arx type IIb). What are the primary limitations to the success of this case? A complex root canal anatomy associated with Type-3b DI morphology A large peri-radicular through and through defect with concurrent apico-marginal defect. Difficulty in weekly and long-term follow-up of the patient.

Management of a severely atrophic maxilla using concentrated platelet-rich fibrin block. A case report

Tooth loss often leads to significant alveolar bone resorption, presenting a challenge for dental implant placement. This case report presents the effectiveness of concentrated platelet-rich fibrin (C-PRF) in combination with bone allograft for horizontal bone augmentation in a severely atrophic maxilla. A 33-year-old female patient with extensive bone loss in the upper anterior maxilla was treated in two stages. The initial stage involved horizontal bone augmentation using a mixture of C-PRF and bone allograft. This was followed, 5 months later, by dental implant placement. The preparation of C-PRF, surgical procedure, and postoperative care are thoroughly described. Post-treatment Cone Beam Computed Tomography showed an increase in alveolar bone thickness from 2.4-3.4 mm pre-operatively to 6.3-7.3 mm, demonstrating the procedure's effectiveness in achieving adequate bone volume for implant placement. The use of C-PRF with allograft in horizontal bone augmentation shows promise in enhancing bone regeneration, especially in a severely atrophic maxilla.

Simultaneous Implant and Guided Bone Regeneration Using Bovine-Derived Xenograft and Acellular Dermal Matrix in Aesthetic Zone

INTRODUCTION

Implant placement in the maxillary anterior area requires sufficient quantity and quality of both soft and hard tissue. In cases where soft and hard tissues are insufficient, additional regeneration using biomaterials is recommended. Treatment using bovine-derived xenograft and acellular dermal matrix (ADM) may increase bone volume and soft tissue thickness. Case and management: A 65-year-old woman sought help for discomfort and aesthetic issues with her denture, reporting missing teeth (11, 12, 13, 14, and 21) and bone volume shrinkage due to disuse atrophy. Intraoral examination revealed 1 mm gingival thickness. CBCT showed labio-palatal bone thickness of 6.0 mm, 5.8 mm, and 4.7 mm for teeth 21, 12 and 14, respectively. Implant planning and surgical guide fabrication were carried out before the surgery. Surgery included the placement of implants 3.3 mm in diameter and 12 mm in length, with the use of xenograft and ADM. Three months post-op, improvements in soft and hard tissues were observed, with a final prosthesis being a long-span implant-supported bridge.

CONCLUSIONS

Disuse alveolar atrophy causes soft and hard tissue deficiency. The use of xenograft and ADM show favourable results even on a geriatric patient.

Association of the Osseodensification Technique with Soft Tissue Substitute in a Limitrophe Edentulous Area: A Clinical Case Report with 5-Year Follow-Up

The osseodensification (OD) technique differs from conventional milling for dental implant installation in that it preserves the prepared bone and compacts it toward the apex and lateral walls of the socket, resulting in bone compaction. By enabling autografting, bone expansion, and high implant insertion torques, OD has become an increasingly popular option. The aim of this clinical case report is to demonstrate the predictability of combining OD with guided bone and tissue regeneration (GBR/GTR) techniques for bone expansion in the maxilla with reduced thickness, while avoiding other reconstructive surgeries. The report presents the treatment of a 32-year-old female patient who had cosmetic concerns regarding the anterior maxillary region. The patient was using an adhesive prosthesis with pontic on tooth 13 fixed between teeth 12 and 14. After the case was planned, it was decided that bone expansion in the region would be performed using the OD technique. The implant installation (AR Torque, 3.5 × 11.5 mm, Conexão®) and guided bone regeneration (GBR) were done with the assistance of L-PRF (Stick Bone, associated with L-PRF membrane). Following the osseointegration period, a provisional resin crown was fabricated, and a collagen matrix membrane (Mucoderm®) was used to increase vestibular soft tissue volume and shape the patient's gingival profile. After a period of 120 days, the final crown was created and observed for a span of 5 years. The results showed stability of the case along with maintaining its esthetic and satisfactory function. The use of the osseodensification technique coupled with a connective tissue graft substitute has been anticipated for a long time. It has proven to be an excellent alternative to autogenous grafts.

Ten years of injectable platelet-rich fibrin

The use of platelet-rich fibrin (PRF) has seen widespread advantages over platelet-rich plasma (PRP) in many fields of medicine. However, until 2014, PRF remained clinically available only in its solid clotted form. Modifications to centrifugation protocols and tube technology have led to the development of a liquid injectable version of PRF (i-PRF). This narrative review takes a look back at the technological developments made throughout the past decade and further elaborates on their future clinical applications. Topics covered include improvements in isolation techniques and protocols, ways to further concentrate i-PRF, and the clinical impact and relevance of cooling i-PRF. Next, various uses of i-PRF are discussed, including its use in regenerative periodontology, implantology, endodontics, temporomandibular joint injections, and orthodontic tooth movement. Furthermore, various indications in medicine are also covered, including its use in sports injuries and osteoarthritis of various joints, treatment of diabetic ulcers/wound care, and facial esthetics and hair regrowth. Finally, future applications are discussed, mainly its use as a drug delivery vehicle for small biomolecules, such as growth factors, antibiotics, exosomes, and other medications that may benefit from the controlled and gradual release of biomolecules over time.

Frequency of surgical bone augmentation methods complementary to dental implant placement: A study evaluated with cone beam computed tomography

Background

The success of dental implants largely depends on the quantity and quality of available bone. Occasionally, it is necessary to perform additional surgical techniques alongside implant placement to increase the available bone volume and ensure the success and survival of treatments. The objective of this study was to evaluate, through cone beam computed tomography, the need for supplementary bone augmentation methods in implant placement. Additionally, the study aimed to assess the frequency of such techniques based on gender, anatomical sectors, and types of bone augmentation procedures.

Material and Methods

The analysis included 106 cone beam computed tomography images obtained from 77 patients over the age of 18 who sought oral rehabilitation with implants at the University Clinic of the Master's Program in Oral Implantology at the European University of Valencia.

Results

A total of 201 edentulous sextants were analyzed. It was observed that 63.68% of the sextants required a bone augmentation technique, and there was a statistically significant difference (p=0.039) regarding the need for supplementary techniques in women. The need for bone augmentation by sectors was most prevalent the horizontal type (48.11%) and in the mandible (29.41%). About crestal and lateral approaches for sinus elevation, there was a higher need for the lateral technique (49.38%), and a statistically significant difference was evident (p=0.015).

Conclusions

A high frequency of bone augmentation need for implant placement was demonstrated. It was shown that some form of supplementary surgical method was required in implant placement (63.68%). The highest need for bone augmentation was observed in the posterior maxillary sector, primarily in the vertical type (29.27%), accompanied by lateral window sinus elevation technique (49.38%). Key words:Bone graft, Dental implant, Guided bone regeneration, Sinus floor augmentation, Cone beam computed tomography.

Implant-Prosthetic Rehabilitation of Mandibular Posttraumatic Severe Dentoalveolar Loss With a Reconstructive Staged Approach: A Clinical Report With 3-Year Follow-Up

This clinical report describes the oral rehabilitation of a 25-year-old male patient who lost the lower incisors, right canine, and a significant amount of anterior mandibular bony and soft tissue following severe dentoalveolar trauma due to a car accident. The patient's young age, anterior esthetic zone in the lower jaw, previous mandibular fracture, and extended bony and soft-tissue defect hindering ideal 3-dimensional implant placement oriented the therapeutic plan toward a staged approach, with several reconstructive surgical procedures before implant rehabilitation. The treatment involved deepening the labiobuccal vestibule and lingual sulcus to correct cicatricial shrinkage due to previous surgical fixation of the mandibular fracture, vertical guided bony augmentation to regenerate adequate volumes of bone, free gingival graft to achieve sufficient height and thickness of peri-implant soft tissues, and a prosthetic-driven surgical procedure to place the implants in a good functional and esthetic position. This therapeutic approach restored function and esthetics and achieved outcome stability at 3-year follow-up.

Efficacy of mixture of injectable-platelet-rich fibrin and type-1 collagen particles on the closure of through-and-through periapical bone defects: A randomized controlled trial

AIM

To determine the efficacy of a combination of injectable-platelet-rich fibrin and type-1 collagen particles on the healing of through-and-through periapical bone defect and subsequent closure of bony window.

METHODOLOGY

The clinical trial was registered in ClinicalTrials.gov (NCT04391725). Thirty-eight individuals with radiographic evidence of periapical radiolucency in maxillary anterior teeth and confirmed loss of palatal cortical plates in cone beam computed tomographic imaging were randomly assigned to either the experimental group (n = 19) or the control group (n = 19). A mixture of i-PRF and collagen as a graft was applied to the defect in adjunct to periapical surgery in the experimental group. No guided bone regeneration procedures were used in the control group. The healing was evaluated using Molven's (2D) and modified PENN 3D (3D) criteria. Percentage reduction of the buccal and palatal bony window area, and complete closure of through-and-through periapical bony window (tunnel defect) were assessed using Radiant Diacom viewer software (Version 4.0.2). The reduction in the periapical lesion area and volume was measured using Corel DRAW and ITK Snap software.

RESULTS

Thirty-four participants (18 and 16 in the experimental and control groups respectively) reported for follow-up at 12 months. There was 96.9% and 97.96% reduction of buccal bony window area in the experimental and control groups respectively. Similarly, palatal window showed 99.03% and 100% reduction in the experimental and control groups respectively. No significant difference in both buccal and palatal window reduction was noticed between the groups. A total of 14 cases (seven in the experimental group and seven in the control group) showed complete closure of through-and-through bony window. No significant difference in clinical, 2D and 3D radiographic healing, percentage reduction in area and volume was observed between the experimental and control groups (p > .05). Neither the area nor the volume of lesion, and the size of buccal or palatal window had significant effect on healing of through-and-through defects.

CONCLUSION

Endodontic microsurgery results in high success rate in large periapical lesions with through-and-through communication with more than 80% reduction in volume of lesion and size of both buccal and palatal window after 1 year. A mixture of type-1 collagen particles and i-PRF, adjunct to periapical micro-surgery did not improve the healing in through-and-through periapical defects.

Techniques on vertical ridge augmentation: Indications and effectiveness

Vertical ridge augmentation techniques have been advocated to enable restoring function and esthetics by means of implant-supported rehabilitation. There are three major modalities. The first is guided bone regeneration, based on the principle of compartmentalization by means of using a barrier membrane, which has been demonstrated to be technically demanding with regard to soft tissue management. This requisite is also applicable in the case of the second modality of bone block grafts. Nonetheless, space creation and maintenance are provided by the solid nature of the graft. The third modality of distraction osteogenesis is also a valid and faster approach. Nonetheless, owing to this technique's inherent shortcomings, this method is currently deprecated. The purpose of this review is to shed light on the state-of-the-art of the different modalities described for vertical ridge augmentation, including the indications, the step-by-step approach, and the effectiveness.

Application of digital technology and platelet-rich fibrin technology in a novel regenerative treatment for posterior lingual furcation defect: a 6-year follow-up case report

Conventional periodontal regenerative surgery has limited effect on tooth with severe periodontitis-related alveolar bone defects. This article reported a case of regenerative treatment in severe distal-bone defect of mandibular first molar. The treatment involved applying 3D printing, advanced/injectable platelet-rich fibrin, and guided tissue-regeneration technology. After the operation, the periodontal clinical index significantly improved and the alveolar bone was well reconstructed.

Resveratrol-loaded co-axial electrospun poly(ε-caprolactone)/chitosan/polyvinyl alcohol membranes for promotion of cells osteogenesis and bone regeneration

The guided bone regeneration (GBR) membranes currently used in clinics are usually compromised by their limited osteogenic induction potential. In this study, we fabricate a core-shell poly(ε-caprolactone)/chitosan/polyvinyl alcohol (PCL/CS/PVA) GBR membrane with different amount of resveratrol (RSV), endowing the PCL/CS/PVA GBR membrane with superior osteogenic induction ability, which was not attained by the regular GBR membrane. The prepared GBR membranes were characterized by scanning electron microscopy, transmission electron microscopy, and CCK-8 and live-dead staining assays, and their osteogenic induction ability was evaluated using Col-I immunofluorescence staining, micro-computed tomography, haematoxylin and eosin staining and immunohistochemical staining. Results of the in vitro release experiment confirmed that the membranes exhibited a continuous RSV release profile for 15 days. Furthermore, the cumulative releasing of RSV was increased from 39.68 ± 2.09 μg to 65.8 ± 2.91 μg with increasing contents of RSV from 0.1 % to 0.5 % (w/v) in the core layer of GBR membranes. In particular, the PCL/CS/PVA GBR membrane loading with 0.5 % RSV most efficiently release RSV in a sustained and controlled manner, which significantly induced osteogenic differentiation of pre-osteoblasts in vitro and bone regeneration in vivo. Based on the in vivo histological findings, newly formed bone tissues with 82.46 ± 9.86 % BV/TV and 0.70 ± 0.07gcm-3 BMD were generated in the defect sites treated by the GBR membrane loaded with 0.5 % RSV, which were the largest values among those for all three groups after 12 weeks of post implantation. Overall, the PCL/CS/PVA GBR membrane loaded with 0.5 % RSV has significant potential for bone regeneration.

Comparative evaluation of regenerative potential of injectable platelet-rich fibrin and platelet-rich fibrin with demineralized freeze-dried bone allograft in the treatment of intrabony defects: A randomized controlled clinical study

Background

Injectable platelet-rich fibrin (i-PRF) being in liquid form keeps graft particles clumped together forming agglutinated steak of bone graft. It has been shown to contain more platelets and long-term deliverance of growth factors in comparison with platelet-rich fibrin (PRF).

Aim

The aim of the present study was to assess regenerative potential of i-PRF and comparing it with PRF, along with demineralized freeze-dried bone allograft (DFDBA) in the treatment of intrabony alveolar defects.

Materials and Method

Thirty defect sites in 15 patients with bilateral intrabony defects were assigned randomly into two groups (Group I (Control group)- DFDBA + PRF and Group II (Test group)-DFDBA + i-PRF). Gingival index (GI), plaque index (PI), pocket probing depth (PPD), and relative attachment level (RAL) were recorded at baseline, 3 months, and 6 months. Linear bone growth (LBG) was recorded radiographically at baseline and 6 months.

Statistical Analysis

ANOVA test and post hoc Tukey test were used to assess intragroup comparison of clinical parameters. Paired t-test was used to assess intragroup comparison of the radiographic parameter. Unpaired t-test was used to assess intergroup variations in all the clinical as well as radiographic parameters.

Results

Statistically significant PPD reduction (P = 0.005) and RAL gain (P = 0.003) were found in Group II than in Group I, and no significant difference was found in other parameters. Percentage LBG was higher in Group II than Group I but the difference was not statistically significant.

Conclusion

i-PRF with DFDBA showed more favorable results as compared to PRF with DFDBA in the management of intrabony periodontal defects.

Platelet-Rich Fibrin in Oral Surgery and Implantology: A Narrative Review

Background

The application of blood concentrates has gained popularity in dentistry in recent years. Platelet-rich fibrin (PRF) has been discussed frequently due to a high content of growth factors and the option of chair-side manufacturing in a simple centrifugation process. PRF is free from adjuvants and inexpensive to produce. The number of studies reporting beneficial effects of PRF in various clinical applications such as alveolar ridge preservation, sinus floor elevation, management and prevention of medical-related osteonecrosis of the jaw, third molar extractions, and guided bone regeneration in dentistry has increased recently. However, to date, neither clinical recommendations nor guidelines are available. The present narrative review aims to summarize the level of evidence on the clinical application of PRF within the field of oral surgery and implantology.

Summary

A literature search in Pubmed and Medline has identified 34 articles as a basis for this narrative review. The effectiveness of the clinical application of PRF has been analyzed for five indications within dentistry: medical-related osteonecrosis of the jaw, wisdom tooth extraction, guided bone regeneration, sinus floor elevation, and alveolar ridge preservation. The amount of data for third molar extractions, socket preservation, and guided bone regeneration is extensive. Less data were available for the use of PRF in combination with sinus floor elevations. There is a lack of studies with scientific evidence on PRF and medical-related osteonecrosis of the jaw; however, studies positively impact patient-related outcome measures. Most studies report on beneficial effects when PRF is additionally applied in intrabony defects. There is no evidence of the positive effects of PRF combined with bone graft materials during sinus floor elevation. However, some benefits are reported with PRF as a sole filling material.

Key Messages

Many recently published studies show the positive clinical impact of PRF. Yet, further research is needed to ensure the validity of the evidence.

A New Biomaterial Derived from Aloe vera-Acemannan from Basic Studies to Clinical Application

Aloe vera is a kind of herb rich in polysaccharides. Acemannan (AC) is considered to be a natural polysaccharide with good biodegradability and biocompatibility extracted from Aloe vera and has a wide range of applications in the biomedical field due to excellent immunomodulatory, antiviral, antitumor, and tissue regeneration effects. In recent years, clinical case reports on the application of AC as a novel biomedical material in tissue regenerative medicine have emerged; it is mainly used in bone tissue engineering, pulp-dentin complex regeneration engineering, and soft tissue repair, among other operations. In addition, multiple studies have proved that the new composite products formed by the combination of AC and other compounds have excellent biological and physical properties and have broader research prospects. This paper introduces the preparation process, surface structure, and application forms of AC; summarizes the influence of acetyl functional group content in AC on its functions; and provides a detailed review of the functional properties, laboratory studies, clinical cutting-edge applications, and combined applications of AC. Finally, the current application status of AC from basic research to clinical treatment is analyzed and its prospects are discussed.

The impact of membrane perforation and L-PRF for vertical ridge augmentation with a xenogeneic block graft: an experimental study in a canine model

OBJECTIVES

This study evaluated clinically and histologically the efficacy of modified perforated collagen membrane (PCM) and/or leukocyte- and platelet-rich fibrin (L-PRF) in combination with xenogeneic block bone graft in the vertical alveolar ridge augmentation.

MATERIALS AND METHODS

Six adult mongrel dogs were enrolled in this randomized blinded study. After defect preparation, xenogeneic screw-fixed block graft was covered by an occlusive collagen membrane in group 1 that represented the control group (Block + CM). In group 2, L-PRF membrane was added first before top coverage by occlusive collagen membrane (Block + L-PRF + CM). Groups 3 (Block + PCM) and 4 (Block + L-PRF + PCM) were identical to the first two groups except that the occlusive collagen membrane was replaced by a perforated one. Following a healing period of 2 months, the dogs were submitted to the surgical reentry phase for clinical and histological evaluation.

RESULTS

Clinically, no significant differences were found among all groups regarding vertical and horizontal ridge dimensions (p = 0.155, 0.492, respectively). Histomorphometric analysis revealed that the percentage of the total bone area and mature bone was significantly higher in group 4 (69.36 ± 2.72, 33.11 ± 5.18) compared to the control group (59.17 ± 4.27, 21.94 ± 2.86) (p = 0. 027, p = 0.029).

CONCLUSION

The use of xenogenic block grafts in combination with a double-layered perforated collagen L-PRF membrane in vertical ridge augmentation appeared to improve the inductive power of this challenging defect type.

CLINICAL RELEVANCE

Size and number of perforations may affect the mechanical and handling properties of the membrane.

Enhancing the osteogenic differentiation of aligned electrospun poly(L-lactic acid) nanofiber scaffolds by incorporation of bioactive calcium silicate nanowires

Bone defects cause serious psychological and economic burden to patients. Artificially bone repairing materials bring hope to the treatment of bone defects. Electrospun technique has attracted great attention since it can fabricate fibers from nano- to micro- scale continuously. Scaffolds fabricated by electrospun can mimic the structure of extracellular matrix which is beneficial to cell adhesion and migration. Researches have showed that bioactive ions (such as silicon and calcium ions) can promote bone regeneration. In addition, physical cues can affect cellular behavior such as cell adhesion and differentiation. In this study, two kinds of calcium silicate - adopted poly (L-lactic acid) (CS-PLLA) electrospun scaffolds with random/aligned structures were prepared by electrospun to promote bone regeneration. The integration of CS nanowires improved the biological property of PLLA electrospun scaffolds. Furthermore, in vitro results indicated that aligned 1 wt% CS adopted PLLA (PCA1) electrospun scaffolds with better physical properties and facilitated cell adhesion, improved alkaline phosphate (ALP) activity and the expression of osteogenic genes (Osteopontin (OPN), Collagen type 1 (Col-1) and Bone morphogenetic protein-2 (BMP-2)) compared with random 1 wt% CS adopted PLLA (PCR1) electrospun scaffolds. In conclusion, the prepared PCA1 electrospun scaffolds might be a potential candidate for bone regeneration in defect areas.

Effect of relative centrifugal force on the biological properties of liquid platelet-rich fibrin produced via horizontal centrifugation

OBJECTIVES

Platelet-rich fibrin (PRF) in liquid form has shown advantages in tissue engineering including acting as injectable fillers and drug carriers. However, few studies have investigated the best relative centrifugal force (RCF) for preparing liquid PRF. The aim of the present study was to find out optimal centrifugation force for preparing liquid PRF.

MATERIALS AND METHODS

Liquid PRF was prepared using horizontal centrifugation (liquid H-PRF) with RCF ranging from 100 g, 300 g, 500 g, to 700 g for 8 min. The volume, weight, solidification time, and tensile properties were subsequently investigated. Scanning electron microscopy (SEM) and rheologic tests were carried out to investigate the microstructure and rheologic properties of liquid H-PRF after natural polymerization. The total number, concentration, and distribution of cells within each liquid H-PRF was evaluated by complete blood count (CBC) analysis and hematoxylin-eosin staining.

RESULTS

As RCF values increased, the volume and weight of liquid H-PRF both increased accordingly. SEM images revealed that as the centrifugal force increased, the fibrin bundles became thinner with a denser fibrin network, and rheologic tests revealed improved mechanical properties. CBC analysis demonstrated that 500 g group had the highest number of leukocytes and neutrophils, whereas 100 g group yielded the highest concentration of leukocytes and platelets. Furthermore, histological analysis suggests that cells obtained by 500 g for 8 min were most evenly distributed in liquid H-PRF.

CONCLUSIONS

In summary, the present study provided insights into the contents of liquid H-PRF prepared at different centrifugation forces, enabling clinicians to choose proper centrifugation forces based on their needs.

CLINICAL RELEVANCE

The present findings provide theoretical basis for clinical choice of liquid H-PRF protocol from mechanical, cell contents, and histological aspects.

Recent advances in biofunctional guided bone regeneration materials for repairing defective alveolar and maxillofacial bone: A review

The anatomy of the oral and maxillofacial sites is complex, and bone defects caused by trauma, tumors, and inflammation in these zones are extremely difficult to repair. Among the most effective and reliable methods to attain osteogenesis, the guided bone regeneration (GBR) technique is extensively applied in defective oral and maxillofacial GBR. Furthermore, endowing biofunctions is crucial for GBR materials applied in repairing defective alveolar and maxillofacial bones. In this review, recent advances in designing and fabricating GBR materials applied in oral and maxillofacial sites are classified and discussed according to their biofunctions, including maintaining space for bone growth; facilitating the adhesion, migration, and proliferation of osteoblasts; facilitating the migration and differentiation of progenitor cells; promoting vascularization; providing immunoregulation to induce osteogenesis; suppressing infection; and effectively mimicking natural tissues using graded biomimetic materials. In addition, new processing strategies (e.g., 3D printing) and new design concepts (e.g., developing bone mimetic extracellular matrix niches and preparing scaffolds to suppress connective tissue to actively acquire space for bone regeneration), are particularly worthy of further study. In the future, GBR materials with richer biological functions are expected to be developed based on an in-depth understanding of the mechanism of bone-GBR-material interactions.

The application of injectable platelet-rich fibrin in regenerative dentistry: A systematic scoping review of In vitro and In vivo studies

Background

Ongoing research in the dental field has begun to focus on the use of injectable platelet-rich fibrin (I-PRF) as a regenerative tool with the potential to prompt tissue regeneration. In this regard, this systematic scoping review aimed to collect, map, and appraise the in vitro and in vivo studies regarding the role of I-PRF in or soft and hard tissue regeneration in relation to oral and maxillofacial structures.

Methods

A systematic electronic search of Medline, Scopus, Web of Science, and Embase databases was performed from 2000 to December 2021 using a combination of keywords. All in vitro and in vivo studies, written in English and concerning the potential role of I-PRF in regenerative dentistry were considered.

Results

In total, 18 in vitro studies, 5 animal studies, 6 case reports, and 31 clinical studies have evaluated the effect of I-PRF on oral and maxillofacial soft and hard tissue regeneration. The investigated studies verified the anti-inflammatory, anti-microbial efficacy and the positive effects of I-PRF application for wound, periodontal, bone, cartilage, and pulp regeneration, as well as acceleration in tooth movement during orthodontic treatment.

Conclusions

Current literature approves the feasibility of I-PRF application as a promising regenerative adjunct to dental procedures.

Evaluation of the effect of autologous conditioned serum on the radiographic characteristics of hard tissue after horizontal bone augmentation in implant dentistry

Background. Bone deficiency in different areas is problematic in implant placement. Changes in histological, histomorphometric, and radiographic properties of hard tissues in the implant placement area affect many parameters of implant success. Autologous conditioned serum (ACS) is a blood product with high levels of IL1- receptor antagonists. Augmentation surgeries are required in many cases because implant placement in the edentulous areas requires a sufficient amount of bone. Therefore, this study radiographically evaluated the effect of autologous conditioned serum after horizontal bone augmentation. Methods. In this prospective RCT, 21 patients eligible patients were evaluated. The patient underwent horizontal ridge augmentation surgery in the area. The ACS-impregnated graft was in direct con-tact with the bone. The control side underwent the same surgical protocol without using ACS. Four months after surgery, a CBCT radiograph was taken, and radiographic changes in the two areas were calculated using the differences in the amount of bone formed in the horizontal dimension as well as the Hounsfield unit (HU). The data were reported using descriptive statistical methods, including means (standard deviations) and frequencies (percentages). According to the results of the Kolmog-orov-Smirnov test, the data had a normal distribution (P>0.05); therefore, paired t-test was used to compare the means of the parameters between the two groups. Results. IRadiographic examinations showed that the horizontal dimension of bone before surgery was similar between the two groups. However, after surgery in the ACS group (33.13±6.1), it was significantly higher than in the control group (62.1±86.4) (P>0.05). Also, the rate of horizontal dimension increase (the difference before and after surgery) in the ACS group was significantly higher than in the control group. Bone density before surgery was similar between the two groups. However, after surgery, there was a significant increase in the ACS group (75.56±330.42 HUs) compared to the control group (38.35±292.38 HUs) (P>0.05). Also, the rate of density increase (the difference before and after surgery) in the ACS group was significantly higher than in the control group. Conclusion. Radiographic evaluations of hard tissues showed a significant increase in the horizontal dimension of bone and density of newly formed bone using ACS compared to the control group.

Customized Titanium Mesh for Guided Bone Regeneration with Autologous Bone and Xenograft

The augmentation of the alveolar crest after the loss of one or several teeth can be carried out using different bone augmentation techniques. These techniques include bone distraction, ridge expansion, bone block grafts, etc. Guided bone regeneration is an alternative to increase the volume of the hard tissues for the subsequent placement of the implants in the optimal three-dimensional position. The objective of this paper is to show a case report of the use of customized titanium mesh for posterior vertical bone regeneration. Case report and Results: A 59-year-old woman comes to rehabilitate edentulous spaces with implants. After taking the anamnesis and the intra and extraoral exploration, a vertical and horizontal bone defect is observed in the third quadrant. After the radiological study with CBCT, a bone height of 6.04 mm to the inferior alveolar nerve and a width of the bone crest of 3.95 mm was observed. It was decided to carry out a regeneration with a preformed titanium mesh (Avinent^®, Santpedor, Spain) and four microscrews (Avinent^®, Santpedor, Spain). The flap was closed without tension. Regular check-ups were performed without complications. At 7 months, the mesh was removed and two osteoingrated implants (Avinent^®, Santpedor, Spain) were placed with a torque greater than 45 N/cm and an ISQ of 82 and 57 N/cm, respectively. The bone gain obtained was 1.84 and 1.92 mm in width and 4.2 and 3.78 mm in height for positions 3.5 and 3.6. The newly formed bone, obtained by trephine, was well-structured and histologically indistinguishable from the previous bone. Conclusion: The use of a customized pre-formed titanium mesh together with the mixture of autologous bone and xenograft is a feasible and predictable technique for vertical bone regeneration.

Emerging roles of platelet concentrates and platelet-derived extracellular vesicles in regenerative periodontology and implant dentistry

Platelet concentrates (PCs) are easily obtained from autogenous whole blood after centrifugation and have evolved through three generations of development to include platelet-rich plasma, platelet-rich fibrin, and concentrated growth factor. Currently, PCs are widely used for sinus floor elevation, alveolar ridge preservation, periodontal bone defects, guided bone regeneration, and treatment of gingival recession. More recently, PCs have been leveraged for tissue regeneration to promote oral soft and hard tissue regeneration in implant dentistry and regenerative periodontology. PCs are ideal for this purpose because they have a high concentration of platelets, growth factors, and cytokines. Platelets have been shown to release extracellular vesicles (P-EVs), which are thought to be essential for PC-induced tissue regeneration. This study reviewed the clinical application of PCs and P-EVs for implant surgery and periodontal tissue regeneration.

Promoting repair of highly purified stromal vascular fraction gel combined with advanced platelet-rich fibrin extract for irradiated skin and soft tissue injury

Background

To evaluate the effect of highly purified stromal vascular fraction gel (SVFG) combined with advanced platelet-rich fibrin extract (APRFE) in treatment of irradiated skin and soft tissue injury.

Methods

The subcutaneous fat and whole blood of 4 rabbits were collected to isolate the SVFG and APRFE, respectively. Forty-eight rabbits were divided into 4 groups to prepare irradiated skin injury models with 25 Gy for 24 hours; corresponding dose were performed subcutaneously injected into wounds. In group A, the rabbits were treated with 0.3 mL APRFE combined with 1 mL SVFG. In group B, the rabbits were treated with 1 mL SVFG. In group C, the rabbits were treated with 0.3 mL APRFE, and group D was treated with 1 mL normal saline. The wound healing was detected on the 2, 5, 9 and 14 d after intervention. The wounds tissue was cut for hematoxylin and eosin (HE) staining to observe the structure and Masson staining to observe the collagen content. The expression of CD31 in each group was detected by immunohistochemistry (IHC), the protein and mRNA levels of K19, hypoxia inducible factor-1 alpha (HIF-1α), vascular endothelial growth factor (VEGF), interleukin 8 (IL-8) and interleukin 10 (IL-10) were detected respectively by Western blot (WB) and reverse transcription-polymerase chain reaction (RT-PCR) on 7, 14 and 28 d after intervention.

Results

It is revealed that wound healing rates from 5 to 14 d in group A was significantly higher than that of control. The wounds healing rates in group B and C were significantly higher than that of control after 12 d. Masson staining results showed that the collagen content in group A was significantly higher than that of the other 3 groups on the 7, 14 and 28 d. The results of IHC showed that the expression of CD31 in group A was significantly higher than that of the other 3 groups on 7, 14 and 28 d. WB and RT-PCR results showed that relative expression levels of K19, HIF-1α, VEGF, IL-10 in group A were significantly higher than that of the other 3 groups on 7, 14 and 28 d. However, the relative expression levels of IL-8 in group A was significantly lower than that of the other 3 groups on 7, 14 and 28 d.

Conclusions

SVFG combined with APRFE can promote the repair of irradiated skin and soft tissue injury by accelerating angiogenesis, promoting collagen synthesis and reducing inflammation.

In-situ mineralized homogeneous collagen-based scaffolds for potential guided bone regeneration

For guided bone regeneration (GBR) in clinical orthopedics, the importance of a suitable scaffold which can provide the space needed for bone regeneration and simultaneously promotes the new bone formation cannot be overemphasized. Due to its excellent biocompatibility, mechanical strength, and similarity in structure and composition to natural bone, the mineralized collagen-based scaffolds have been increasingly considered as promising GBR scaffolds. Herein, we propose a novel method to fabricate an in-situ mineralized homogeneous collagen-based scaffold (IMHCS) with excellent osteogenic capability for GBR by electrospinning the collagen solution in combination with essential mineral ions. The IMHCS exhibited homogeneous distribution of apatite crystals in electrospun fibers, which helped to achieve a significantly higher tensile strength than the pure collagen scaffold (CS) and the scaffold with directly added nano-hydroxyapatite particles (HAS). Furthermore, the IMHCS had significantly better cell compatibility, cell migration ratio, and osteogenic differentiation property than the HAS and CS. Therefore, the IMHCS not only retains traditional function of inhibiting fibroblast invasion, but also possesses excellent osteogenic differentiation property, indicating a robust alternative for GBR applications.

Growth Factor Release within Liquid and Solid PRF

Aim: The purpose of this study was to obtain data concerning growth factor release within liquid and solid platelet-rich fibrin (PRF) matrices and to estimate the amount of potential interindividual variations as a basis for further preclinical and clinical trials. Therefore, we aimed to determine possible differences in the release of growth factors between liquid and solid PRF. Materials and Methods: Blood samples obtained from four subjects were processed to both liquid and solid PRF matrices using a standard centrifugation protocol. Five growth factors (vascular endothelial growth factor, VEGF; epidermal growth factor, EGF; platelet-derived growth factor-BB, PDGF-BB; transforming growth factor-β1, TGF-β1; and matrix metallopeptidase 9, MMP-9) have been evaluated at six time points by ELISA over a total observation period of 10 days (1 h, 7 h, 1 d, 2 d, 7 d, and 10 d). Results: Growth factor release could be measured in all samples at each time point. Comparing liquid and solid PRF matrices, no significant differences were detected (p > 0.05). The mean release of VEGF, TGFβ-1, PDGF-BB, and MMP-9 raised to a peak at time point five (day 7) in both liquid and solid PRF matrices. VEGF release was lower in liquid PRF than in solid PRF, whereas those of PDGF-BB and MMP-9 were higher in liquid PRF than in solid PRF at all time points. EGF had its peak release already at time point two after 7 h in liquid and solid matrices (hour 7 EGF solid: mean = 180 pg/mL, SD = 81; EGF liquid: mean = 218 pg/mL, SD = 64), declined rapidly until day 2, and had a second slight peak on day 7 in both groups (day 7 EGF solid: mean = 182 pg/mL, SD = 189; EGF liquid: mean = 81 pg/mL, SD = 70). Conclusions: This study detected growth factor release within liquid and solid PRF matrices with little variations. Further preclinical trials are needed to precisely analyze the growth factor release in larger samples and to better understand their effects on wound healing in different clinical indications.

Customized 3D printed nanohydroxyapatite bone block grafts for implant sites: a case series

PATIENTS

A case series of 12 patients (mean age, 53.5 years) with horizontal ridge deficiencies had augmentations with customized 3D printed nanohydroxyapatite (3DHA) block grafts prior to implant placement. 3DHA graft materials were fabricated to fit the individual patient defects using DICOMs from CBCT images obtained from each patient. The CBCT images were then converted into the STL file format and 3DHA was reconstructed by 3D printing. Surgical bone augmentation consisted of 3DHA incorporating concentrated growth factors (CGFs) and platelet-rich fibrin (PRF) membrane. At 6 months, a bone biopsy and implantation were performed. The primary outcome was horizontal bone gain after 6 months. The secondary outcomes included information on the clinical outcomes, dimensions, and histomorphometric results.

DISCUSSION

The 3DHA block graft was successful in 10 of 12 patients. Graft adjustment was not required. All 3DHA adapted and fit well at all defect sites. Maximum mean horizontal bone gains were 3.06 ± 1.02 and 3.56 ± 0.23 mm from the DICOMs and STL data sets, respectively. The volume gain was 229.8 ± 82.96 mm³. A low pain score after surgery was reported of 1.41 ± 0.51, while the healing index score increased with a maximum mean of 4.7 ± 0.67. Thirteen implants were placed with good primary stability (ISQ = 65 ± 4.08), without additional guided bone regeneration. Histomorphometric analysis revealed that new bone formation, bone tissue, residual grafts, and connective tissue were 28.6 ± 1.88, 30.48 ± 4.81, 19.82 ± 4.07, and 20.81 ± 4.41%, respectively.

CONCLUSIONS

A customized 3DHA block graft is a viable treatment option for primary implant-site augmentation.

Customized Barrier Membrane (Titanium Alloy, Poly Ether-Ether Ketone and Unsintered Hydroxyapatite/Poly-l-Lactide) for Guided Bone Regeneration

Sufficient bone volume is indispensable to achieve functional and aesthetic results in the fields of oral oncology, trauma, and implantology. Currently, guided bone regeneration (GBR) is widely used in reconstructing the alveolar ridge and repairing bone defects owing to its low technical sensitivity and considerable osteogenic effect. However, traditional barrier membranes such as collagen membranes or commercial titanium mesh cannot meet clinical requirements, such as lack of space-preserving ability, or may lead to more complications. With the development of digitalization and three-dimensional printing technology, the above problems can be addressed by employing customized barrier membranes to achieve space maintenance, precise predictability of bone graft, and optimization of patient-specific strategies. The article reviews the processes and advantages of three-dimensional computer-assisted surgery with GBR in maxillofacial reconstruction and alveolar bone augmentation; the properties of materials used in fabricating customized bone regeneration sheets; the promising bone regeneration potency of customized barrier membranes in clinical applications; and up-to-date achievements. This review aims to present a reference on the clinical aspects and future applications of customized barrier membranes.

Additive Manufacturing Technologies for Fabrication of Biomaterials for Surgical Procedures in Dentistry: A Narrative Review

PURPOSE

To screen and critically appraise available literature regarding additive manufacturing technologies for bone graft material fabrication in dentistry.

MATERIAL AND METHODS

PubMed and Scopus were searched up to May 2021. Studies reporting the additive manufacturing techniques to manufacture scaffolds for intraoral bone defect reconstruction were considered eligible. A narrative review was synthesized to discuss the techniques for bone graft material fabrication in dentistry and the biomaterials used.

RESULTS

The databases search resulted in 933 articles. After removing duplicate articles (128 articles), the titles and abstracts of the remaining articles (805 articles) were evaluated. A total of 89 articles were included in this review. Reading these articles, 5 categories of additive manufacturing techniques were identified: material jetting, powder bed fusion, vat photopolymerization, binder jetting, and material extrusion.

CONCLUSIONS

Additive manufacturing technologies for bone graft material fabrication in dentistry, especially 3D bioprinting approaches, have been successfully used to fabricate bone graft material with distinct compositions.

Guided Bone Regeneration in the Edentulous Atrophic Maxilla Using Deproteinized Bovine Bone Mineral (DBBM) Combined with Platelet-Rich Fibrin (PRF)-A Prospective Study

Background: Bone regeneration procedures represent a major challenge in oral surgery. This study aimed to evaluate a composite PRF/particulate xenograft in guided bone regeneration. Methods: Edentulous patients with horizontal ridge deficiencies in the anterior maxilla and candidates to an immediate-loading full-arch rehabilitation were included. Horizontal linear measurements indicating bone gain were assessed from computer beam computer tomography (CBCT) scans obtained at pre-surgery, post-surgery, and the 12-month follow-up. Mean bone values were presented as mean ± 95% CI. Non-parametric tests were used as appropriate, and the effect size was calculated with Cohen’s d repeated measures. Results: Eighteen patients were rehabilitated with 72 implants. The mean horizontal bone width was 4.47 [4.13–4.80] mm pre-surgically, 9.25 [8.76–9.75] mm post-surgically, and 7.71 [7.28–8.14] mm 12 months after. Conclusions: PRF associated with a xenograft seems to promote an effective horizontal bone gain. Randomized clinical trials are needed to confirm the benefits of this surgical approach.

Ridge Augmentation Is a Prerequisite for Successful Implant Placement: A Literature Review

Alveolar ridge defects are commonly seen in partially dentate patients, and they jeopardize speech, appearance, and oral hygiene maintenance. These defects affect both soft tissues and bone and are mainly caused by trauma. These defects are more prevalent in middle-aged male patients and it is imperative that the defective ridge is augmented before receiving an implant or a fixed partial denture. This review focuses on the different types of ridge defects and their treatment options.

Efficacy of i-PRF in regenerative endodontics therapy for mature permanent teeth with pulp necrosis: study protocol for a multicentre randomised controlled trial

BACKGROUND

Dental pulp necrosis, a common health problem, is traditionally treated with root canal therapy; however, it fails in restoring the vitality of damaged pulp. Most studies regarding regenerative endodontic therapy (RET) are limited to the treatment of immature necrotic teeth. Given that injectable platelet-rich fibrin (i-PRF) has shown great potential in regenerative medicine as a novel platelet concentration, this study is designed to explore whether i-PRF can serve as a biological scaffold, extending the indications for RET and improving the clinical feasibility of RET in mature permanent teeth with pulp necrosis.

METHODS

This is a randomised, double-blind, controlled, multicentre clinical trial designed to evaluate the clinical feasibility of RET for mature permanent teeth with pulp necrosis and to compare the efficacy of i-PRF and blood clots as scaffolds in RET. A total of 346 patients will be recruited from three centres and randomised at an allocation ratio of 1:1 to receive RET with either a blood clot or i-PRF. The changes in subjective symptoms, clinical examinations, and imaging examinations will be tracked longitudinally for a period of 24 months. The primary outcome is the success rate of RET after 24 months. The secondary outcome is the change in pulp vitality measured via thermal and electric pulp tests. In addition, the incidence of adverse events such as discolouration, reinfection, and root resorption will be recorded for a safety evaluation.

DISCUSSION

This study will evaluate the clinical feasibility of RET in mature permanent teeth with pulp necrosis, providing information regarding the efficacy, benefits, and safety of RET with i-PRF. These results may contribute to changes in the treatment of pulp necrosis in mature permanent teeth and reveal the potential of i-PRF as a novel biological scaffold for RET.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04313010 . Registered on 19 March 2020.

Guided bone regeneration simultaneous with implant placement using bovine-derived xenograft with and without liquid platelet-rich fibrin: a randomized controlled clinical trial

OBJECTIVE

To assess augmentation success after guided bone regeneration (GBR) carried out simultaneously with implant placement using bovine-derived xenograft alone and in combination with liquid platelet-rich fibrin (liquid-PRF).

METHODS

This randomized controlled clinical trial was conducted on patients with horizontal bone deficiency in the posterior regions of the mandible. After implant placement, GBR procedures were randomly performed using liquid-PRF-enriched bovine-derived xenograft (for the test group) and with bovine-derived xenograft alone (for the control group). To assess the change in augmentation thickness, the primary outcome of the study, cone beam computed tomography was carried out at the implant sites on completion and 6 months after surgery. The secondary outcomes were marginal bone level and implant survival rate at prosthetic delivery and at 6 months, 1 year, and 2 years follow-up after loading. The significance level was set at p<0.05 for all analysis.

RESULTS

Twenty patients with 50 implants were analyzed for the test group and 20 patients with 48 implants for the control group. At 6 months postoperatively, the mean values of augmentation thickness were 1.63 ± 0.21 mm, 2.59 ± 0.34 mm, and 3.11 ± 0.36 mm for the test group and 1.34 ± 0.14 mm, 2.49 ± 0.24 mm, and 2.97 ± 0.24 mm for the control group at 2 mm, 4 mm, and 6 mm below to the implant shoulder (p < 0.001, p = 0.007, and p = 0.036, respectively). The mean marginal bone loss was found to be less than 1 mm for both study groups during the 2 years of follow-up after prosthetic loading. Implant survival rate was 100% for both study groups.

CONCLUSION

Bovine-derived xenograft alone and in combination with liquid-PRF are both successful in achieving bone augmentation around the implants and produce a small change in marginal bone level and a high implant survival rate after loading.

CLINICAL RELEVANCE

There is a lack of evidence in the literature regarding the augmentation success of liquid-PRF used in combination with bone graft substitutes. This study indicates that liquid-PRF could be used as a supportive material with bovine-derived xenograft in GBR procedures carried out simultaneously with implant placement.

Alveolar Bone Ridge Augmentation Using Polymeric Membranes: A Systematic Review and Meta-Analysis

Alveolar bone ridge resorption occurred after natural teeth loss and it can restrict the possibility of dental implants placement. The use of bone regenerative procedures is frequently required. The existing evidence regarding the efficacy of horizontal bone ridge augmentation trough guided bone regeneration (GBR) using polymeric membranes was stated. A systematic review and meta-analysis were performed. Electronic and manual literature searches were conducted. Screening process was done using the National Library of Medicine (MEDLINE by PubMed), Embase, and the Cochrane Oral Health. Included articles were randomized controlled trials and observational studies. Weighted means were calculated. Heterogeneity was determined using Higgins (I2). If I2 > 50% a random-effects model was applied. It was found that the mean of horizontal bone gain was 3.95 mm, ranging from 3.19 to 4.70 mm (confidence interval 95%). Heterogeneity is I2 = 99% (confidence interval 95%) and significance of the random-effects model was p < 0.001. The complications rate was 8.4% and membrane exposure was the most frequent. Through this study, we were able to conclude that the existing scientific evidence suggests that GBR using polymeric membranes is a predictable technique for achieving horizontal bone augmentation, thus, permitting a proper further implant placement.