Combining platelet rich fibrin with different bone graft materials: An experimental study on the histopathological and immunohistochemical aspects of bone healing

Advancements in alveolar bone grafting and ridge preservation: a narrative review on materials, techniques, and clinical outcomes

This narrative review systematically explores the progression of materials and techniques in alveolar ridge preservation (ARP). We commence by delineating the evolution from traditional ARP methods to cutting-edge alternatives, including platelet-rich fibrin, injectable bone repair materials, and hydrogel systems. Critical examination of various studies reveals these innovative approaches not only accelerate bone healing but also significantly improve patient-reported outcomes, such as satisfaction, pain perception, and overall quality of life. Emphasis is placed on the correlation between advanced ARP techniques and enhanced patient comfort and clinical efficacy, underscoring their transformative potential in dental implantology. Highlighting the effectiveness of ARP, the implant survival rate over a span of 5 to 7 years was high, showcasing the reliability and success of these methods. Further, patients expressed high aesthetic satisfaction with the soft tissue outcome, evidenced by an average visual analog scale (VAS) score of 94. This positive aesthetic appraisal is linked to the clinical health of implants, potentially due to the employment of tooth-supported surgical guides. The economic analysis reveals a varied cost range for bone graft substitutes ($46.2 to $140) and socket sealing materials ($12 to $189), with a noteworthy correlation between the investment in barrier membranes and the diminished horizontal and vertical ridge resorption. This suggests that membrane usage significantly contributes to preserving ridge dimensions, offering a cost-effective strategy for enhancing ARP outcomes. In conclusion, this review illuminates the significant advancements in ARP, highlighting the shift towards innovative materials and techniques that not only promise enhanced bone regeneration and reduced healing times but also improve patient satisfaction and aesthetic outcomes. The documented high implant survival rate and the beneficial economic implications of membrane use further validate the effectiveness of contemporary ARP strategies, paving the way for their broader adoption in dental implantology.

Liquid platelet-rich fibrin in root surface biomodification during gingival recession treatment: Randomized, controlled, split-mouth, clinical trial

BACKGROUND AND OBJECTIVE

Free gingival graft (FGG) has been successfully used in the treatment of gingival recessions, as it is the most predictable technique for increasing the attached gingiva. This study aimed to evaluate the effect of liquid platelet-rich fibrin (PRF) with FGG on root surface coverage as root surface biomodification.

MATERIALS AND METHODS

The research sample consisted of 32 surgical sites in 16 patients, they had 2 bilateral recessions in the incisor area of the same dental arch, the sample was divided into 2 groups randomly, and liquid PRF was applied in the first group with the FGG (experimental group), and in the second group the FGG was applied alone (control group). Gingival recession depth (RD) and width of attached gingiva (WAG) were measured before starting, after 1, 3, and 6 months. The percentage of root coverage (RC) was calculated after 6 months. Healing Index (HI) was recorded after 1 week, 2 weeks, and 1 month.

RESULTS

Both groups showed a reduction in gingival RD during all follow-up periods but the difference between both groups was not statistically significant (p > 0.05) at 1 and 3 months, whereas there were significant differences at 6 months (p = 0.001). RC was better in the liquid PRF group than in the control group, but this difference was not statistically significant (p > 0.05). The postoperative 7th and 14th days HI scores of the liquid PRF group were significantly better than the control group (p = 0.000 and p = 0.004, respectively), whereas there were no significant differences in HI scores between both groups at first month (p > 0.05).

CONCLUSIONS

According to the results, the addition of liquid PRF to the root surface with FGG showed further development in terms of decreasing RD, increasing WAG, and accelerated wound-healing.

Use of Injectable Platelet-Rich Fibrin Accompanied by Bone Graft in Socket Endurance: A Radiographic and Histological Study

Background Ridge preservation became a crucial dental health issue and strategy to keep away from ridge defacement after post-tooth loss. The recent scientific evolution of platelet-rich fibrin (PRF) comprises a parenteral formulation of PRF. The combined allograft for socket preservation gives benefits. In this study, bone allografts, demineralized freeze-dried bone allografts (DFDBA) and freeze-dried bone allografts (FDBA) are used in a 30:70 ratio alone or in combination with injectable PRF (I-PRF) for socket preservation. Methods This study is a radiographic and histological examination conducted on 60 participants aged between 19-65 years. Participating patients agreed voluntarily that they would not bear any fixed prosthesis for the next nine months and plan for implanted teeth placement, including multi-rooted mandibular molars denticles. Both groups received atraumatic extraction; then, the socket was preserved with bone allograft alone in the control group and bone allograft mixed with I-PRF, forming sticky bone, in the experimental group. Clinical, radiological, and histological assessments were taken at the inception stage, three months, six months, and nine months. A multivariate regression model and a generalized estimating equation (GEE) model were used to analyse the effects of these changes on outcomes. Results In all the parameters, the test group indicated a good amount of bone growth with increasing intervals of time for bone height radiographically with statistically significant difference present (p<0.05) and histologically after nine months when socket site grafted with bone graft in combination with I-PRF. Conclusion This study's results demonstrated that I-PRF possesses the potential to regenerate and heal in the tooth-extracted socket. This study further recommends the implementation of I-PRF in safeguarding and conserving the raised rim of the tooth. Future research should take place on the osteogenic capability of I-PRF in more comprehensive ridge accession surgical procedures and additional expanding and improving capacities in periodontal reconstruction.

Application of advanced platelet-rich fibrin for through-and-through bony defect during endodontic surgery: Three case reports and review of the literature

BACKGROUND

The use of advanced platelet-rich fibrin (A-PRF) membranes for guided bone and tissue regeneration in through-and-through defects after endodontic surgery was explored in three cases.

CASE SUMMARY

Herein, three patients presented to the endodontic clinic suffering from apical periodontitis, associated with large bone resorption and related to previously endodontically treated teeth. Periapical surgery was indicated in these cases and the osteotomy site was covered by A-PRF membrane. Cone-beam computed tomography (CBCT) was used to assess the cases before and after the surgery.

CONCLUSION

Four months post-surgery, the recall CBCT scan showed complete obliteration of the osteotomy with newly formed bone. A-PRF membrane showed promising results and was an advantageous addition to surgical endodontic treatment.

Standardization of Animal Models and Techniques for Platelet-Rich Fibrin Production: A Narrative Review and Guideline

Experimental research is critical for advancing medical knowledge and enhancing patient outcomes, including in vitro and in vivo preclinical assessments. Platelet-rich fibrin (PRF) is a blood by-product that has garnered attention in the medical and dental fields due to its potential for tissue regeneration and wound healing. Animal models, such as rabbits and rats, have been used to produce PRF and examine its properties and applications. PRF has demonstrated potential in the dental and medical fields for reducing inflammation, promoting tissue repair, and accelerating wound healing. This narrative review aims to compare existing evidence and provide guidelines for PRF animal research, emphasizing the importance of standardizing animal models, following ethical considerations, and maintaining transparency and accountability. The authors highlight the necessity to use the correct relative centrifugal force (RCF), standardize centrifugal calibration, and report detailed information about blood collection and centrifuge parameters for reproducible results. Standardizing animal models and techniques is crucial for narrowing the gap between laboratory research and clinical applications, ultimately enhancing the translation of findings from bench to bedside.

Investigating effects of locally applied boric acid on fracture healing with and without low-level laser therapy

This study aimed to investigate the effects on fracture healing of locally applied boric acid (BA) with and without low-level laser therapy (LLLT). A unicortical femoral defect was surgically created on the anterolateral surface of proximal femur of each subject. The subjects, totaling 56 Wistar albino rats, were randomly allocated into four groups (n = 14 each): control, LLLT (λ = 905 μm, 10,000 Hz, 25 mW, and peak power 25 W), BA (40 mg/kg), and BA + LLLT groups. On the 30th day, the highest radiological score was recorded for the BA + LLLT group (3.63 [2-4]), followed by the BA (3.38 [2.75-3.75]), control (3 [2-3.25]), and LLLT (2.5 [1.25-3]) groups. On days 15 and 30 post-surgery, malondialdehyde levels were significantly lower among the BA + LLLT group compared to the control group (p < 0.001). On day 30, superoxide dismutase, catalase, and alkaline phosphatase levels were highest in the BA + LLLT group compared to the control group (p < 0.001). When the histopathological, immunofluorescence, and immunohistochemical findings on the 15th and 30th days were compared with the control group, a statistically significant difference was found for the BA and BA + LLLT groups (p ˂ 0.05). This study suggests that locally applied BA with LLLT may accelerate fracture healing.

Combination of Nanocrystalline Hydroxyapatite and Injectable Platelet-Rich Fibrin on Bone Graft Materials for Alveolar Bone Preservation

Alveolar bone resorption is one of post-extraction complications with a reduction in the dimensions and quality of the alveolar bone, which will make it challenging to install dental implants in the future. The resorption can be prevented by preserving the alveolar bone using bone grafts. Nanocrystalline hydroxyapatite (HA) is a widely developed material as a bone graft. However, there are still some limitations because it only has osteoconductive properties. The addition of injectable platelet-rich fibrin to HA can increase this material’s osteoinductive, antibacterial, and anti-inflammatory properties, making it suitable for use as bone graft material for the preservation of alveolar bone.

Histological and Histomorphometric Evaluation of Post-Extractive Sites Filled with a New Bone Substitute with or without Autologous Plate Concentrates: One-Year Randomized Controlled Trial

The purpose of the present study was to evaluate the histological and histomorphometric characteristics of post-extraction sites grafted with decellularized bovine compact bone from bovine femur, mixed and unmixed with leukocyte- and platelet-rich fibrin after four months of healing. This study was designed as a randomized controlled trial of parallel groups. Patients in need of a single, implant-supported restoration to replace a hopeless tooth were recruited for tooth extraction and implant placement four months after socket preservation procedure. After tooth extraction, patients were randomly allocated to receive decellularized bovine compact bone from bovine femur, mixed and unmixed with leukocyte- and platelet-rich fibrin. After four months of healing, tapered implants were inserted with an insertion torque between 35 and 45 Ncm. Two months later, implants were loaded with screw-retained definitive crowns. Outcome measures were implant (ISR) and prosthesis (PSR) survival rates, complications, histological and histomorphometric analyses, radiographic marginal bone-level changes, and patients' satisfaction. Clinical data were collected up to one year after tooth extraction and socket preservation procedures. Thirty patients were consecutively enrolled in the trial (15 in each group). Unfortunately, due to the COVID-19 pandemic, bone samples were collected only in 19 patients. Two implants failed before definitive prosthesis delivery (ISR 93.3%). No prosthesis failed (PSR 100%). Three complications were experienced in the control group. The mean bone percentage was 40.64 ± 18.76 in the test group and 33.40 ± 22.38 in the control group. The difference was not statistically significant (p = 0.4846). The mean soft tissue percentage was 32.55 ± 19.45 in the test group and 55.23 ± 17.64 in the control group. The difference was statistically significant (p = 0.0235). The mean residual graft was 24.59 ± 18.39 in the test group and 11.37 ± 12.12 in the control group. The difference was not statistically significant (p = 0.0992). Mean marginal bone loss, as well as patient satisfaction, showed no differences between groups. With the limitations of the present study, socket preservation with L-PRF mixed with decellularized bovine compact bone demonstrated favorable results, comparing with decellularized bovine compact bone from bovine femur alone. Further studies with larger sample size and longer follow-up are needed to confirm these preliminary results.

Evaluation of the efficacy of salmon calcitonin nasal spray on bone healing following open reduction and internal fixation of mandibular fractures - A randomized controlled trial

The objective of this study was to assess the efficacy of calcitonin spray on bone healing following open reduction internal fixation (ORIF) of mandibular fractures. Fourteen patients were subdivided into a study group and a control group. A standardized surgical protocol for ORIF was followed. Postoperatively, salmon calcitonin nasal spray was administered to only the study group. The outcome parameters assessed were serum osteocalcin, pain, and radiographic bone healing. Serum osteocalcin was assessed pre- and postoperatively. Postoperative pain was documented using a visual analogue scale (VAS) on the 7th, 14th, 23rd, and 30th days. An orthopantomogram was used to score fracture healing at four time intervals, as follows: 1 - absence of callus; 2 - presence of minimal callus; 3 - considerable callus; and 4 - complete fusion of fracture. Pain scores were lower for the study group, with no pain from the fifth day, while the control group produced a mean score for day 5 of 2.43 ± 0.98 (p = 0.001). Mean postoperative serum osteocalcin levels were higher for the study group (67.82 ± 8.89) compared with the control group (57.69 ± 6.22; p = 0.029). Bone healing at 12 weeks postoperatively was level 4 for 28.6% of patients in the study group and level 3 for 71.4%. In comparison, 85.7% in the control group demonstrated level 3 healing, while 14.3% remained at level 2 (p = 0.462). Within the limitations of the study, it can be concluded that intranasal salmon calcitonin spray reduces postoperative pain and facilitates fracture healing, although its economic efficiency is still to be proven.

Platelet-rich fibrin-loaded PCL/chitosan core-shell fibers scaffold for enhanced osteogenic differentiation of mesenchymal stem cells

Here, we fabricated the platelet-rich fibrin (PRF)-loaded PCL/chitosan (PCL/CS-PRF) core-shell nanofibrous scaffold through a coaxial electrospinning method. Our goal was to evaluate the effect of CS-RPF in the core layer of the nanofibrous on the osteogenic differentiation of human mesenchymal stem cells (HMSCs). The elastic modulus of PCL/CS-PRF core-shell scaffold (44 MPa) was about 1.5-fold of PCL/CS scaffold (25 MPa). The specific surface area of the scaffolds increased from 9.98 m²/g for PCL/CS scaffold to 16.66 m²/g for the PCL/CS-PRF core-shell nanofibrous scaffold. Moreover, the release rate of PRF from PCL/CS-PRF nanofibrous scaffold was measured to be 24.50% after 10 days which showed slow and sustained release of PRF from the nanofibrous. The formation of Ca-P on the surface of scaffold immersed in simulated body fluid solution indicated the suitable osteoconductivity of PCL/CS-PRF core-shell nanofibrous scaffold. Also, the value of ALP activity and calcium deposited on the surface of PCL/CS-PRF core-shell nanofibrous scaffold were 81.97 U/L and 40.33 μg/scaffold, respectively after 14 days, which confirmed the significantly higher amounts of ALP and calcium deposition on the scaffold containing PRF compared to PCL/CS scaffold. Due to higher hydrophilicity and porosity of PCL/CS-PRF core-shell nanofibrous scaffold compared to PCL/CS scaffold, a better bone cell growth on surface of PCL/CS-PRF scaffold was observed. The Alizarin red-positive area was significantly higher on PCL/CS-PRF scaffold compared to PCL/CS scaffold, indicating more calcium deposition and osteogenic differentiation of HMSCs in the presence of PRF. Our findings demonstrate that PCL/CS-PRF core-shell scaffolds can provide a strong construct with improved osteogenic for bone tissue engineering applications.

Efficiency of advanced-PRF usage in the treatment of alveolar cleft with iliac bone graft: A retrospective study

The aim of this study was to evaluate the efficiency of a new alveolar bone grafting protocol using advanced-PRF (a-PRF) by comparing the volumes of newly formed bone after a bone graft combining autogenous iliac crest bone with either PRF or a-PRF. Patients presenting with unilateral or a bilateral alveolar cleft were included retrospectively in two groups: one group was grafted using cancellous iliac crest bone with PRF (PRF group), whereas for the other group the same procedure was followed using a-PRF (a-PRF group). CBCT scans were performed 3 months preoperatively and 6 months postoperatively. The volume of newly formed bone was measured by subtracting the postoperative cleft volume from the preoperative cleft volume. The mean volume of newly formed bone was compared between the two groups using Student's t-test. Twenty-four patients were included, with 12 allocated to each group. Forty-eight CBCT scans were analyzed. The mean volume of newly formed bone was 0.29 (±0.09) cm³ in the a-PRF group, versus 0.20 (±0.08) cm³ in the PRF group (Student's t-test, p = 0.024). The percentage of newly formed bone was 60.4 (±10.4) % in the a-PRF group versus 51.4 (±18.4) % in the PRF group (Student's t-test, p = 0.165). Our study demonstrated improved bone regeneration in the a-PRF group. While bearing in mind the limitations of this study, the a-PRF procedure should be adopted in cleft bone grafting whenever possible.

Novel applications of platelet concentrates in tissue regeneration (Review)

Numerous studies have explored the suitability of biocompatible materials in regenerative medicine. Platelet concentrates are derived from centrifuged blood and are named according to their biological characteristics, such as platelet-rich plasma, platelet-rich fibrin and concentrated growth factor. Platelet concentrates have gained considerable attention in soft and hard tissue engineering. Indeed, multiple components of autologous platelet concentrates, such as growth factors, fibrin matrix and platelets, serve essential roles in wound healing. Current studies are focused on cutting-edge strategies to meet the requirements for tissue restoration by improving the properties of autologous platelet concentrates. In the present review, applications of platelet concentrates for tissue engineering are discussed, presenting a selection of recent advances and novel protocols. In addition, several aspects of these strategies, such as the advantages of lyophilized platelet concentrates and the combination of platelet concentrates with biomaterials, stem cells or drugs are discussed. The present review aims to summarize novel strategies using platelet concentrates to improve the outcomes of wound healing.

Histological comparison of DBBM and platelet rich fibrin for guided bone regeneration in a rabbit model

Purpose

To histologically evaluate the use of bovine derived deproteinized xenograft (DBBM), leukocyte and platelet rich fibrin (L-PRF) and the combination of both in Guided Bone Regeneration (GBR) performed in non-critical size defects in rabbit.

Methods

A prospective experimental study was performed. Four bone defects in the tibiae of 12 rabbits were made and each of them was filled with DBBM, L-PRF, a combination of DBBM + L-PRF or was left to heal as control site. All defects were covered with a collagen membrane. Rabbits were randomly distributed in three groups and euthanatized at 3, 6 or 9 weeks. Samples were obtained and histologically analyzed to determine vital bone, connective tissue and remaining graft particles percentage. Analysis of variance, Kruskal Wallis and non-paired t-test where used to evaluate the significance of the results.

Results

At 3 weeks of healing, DBBM showed significantly more vital bone percentage than L-PRF (p = 0,05) and DBBM + L-PRF showed significantly less connective tissue than control (p < 0,05). All other groups showed no statistical difference between them. At 6 weeks of healing, DBBM showed significantly more vital bone percentage than L-PRF (p < 0,05), DBBM + L-PRF (p < 0,05) and control (p < 0,05) and there wasn't any other significant difference regarding to connective tissue or remaining particle percentage between groups. At t 9 weeks healing period, there weren't any significant differences between groups.

Conclusions

DBBM seems to enhance vital bone formation at early healing stages. The use of L-PRF alone or combined with DBBM, didn't show any histological improvement regarding to vital bone formation. The use of DBBM, alone or in conjunction with L-PRF showed a trend to reduce connective tissue percentage. The use of L-PRF combined with DBBM didn't affect the remaining particle percentage.

Does platelet-rich fibrin increase stability of the maxilla following Le Fort I osteotomy? A single-blind clinical trial study

This single-blind clinical trial study aimed to assess the efficacy of platelet-rich fibrin (PRF) in increasing stability following Le Fort I osteotomy for maxillary advancement. Patients who underwent Le Fort I osteotomy for maxillary advancement were assigned randomly into two groups: in group 1 (the study group, n = 22) PRF was placed in the osteotomy sites following fixation, while no PRF was used in group 2 (the control group, n = 22). Lateral cephalograms obtained preoperatively (T0), immediately after surgery (T1), and 1 year after surgery (T2) were compared between the two groups, and the amount of relapse was determined. The amount of maxillary change (relapse) at the A point in relation to the x-axis was 0.45 ± 0.67 mm in group 1 and 1.86 ± 0.56 mm in group 2. There was a significant difference in mean relapse in relation to the x-axis between the two groups 12 months after osteotomy (p < 0.001). The mean maxillary change (relapse) in relation to the y-axis was 0.77 ± 1.15 mm in group 1 and 2.25 ± 1.22 mm in group 2. Analysis of the data demonstrated a significant difference in mean relapse in relation to the y-axis between the two groups (p < 0.001). PRF may enhance the stability of the maxilla following Le Fort I osteotomy. Based on the results of this study the administration of PRF should be considered whenever possible.

Combination of an allogenic and a xenogenic bone substitute material with injectable platelet-rich fibrin - A comparative in vitro study

The aim of the in vitro study was a comparison of an allogenic (ABSM) and a xenogenic bone substitute material (XBSM) with and without injectable platelet-rich fibrin (ABSM-i-PRF & XBSM-i-PRF) on cell characteristics of human osteoblasts (HOB). Here, ABSM and XBSM (+ i-PRF = test; - i-PRF = control) were incubated with HOB for 3, 7 and 10 days. HOB viability, migration, proliferation and differentiation (RT-PCR on alkaline phosphatase (AP), bone morphogenetic protein 2 (BMP-2) and osteonectin (OCN)) were measured and compared between groups. At day 3, an increased viability, migration and proliferation was seen for ABSM-i-PRF. For viability and proliferation (days 7 and 10) and for migration (day 10), ABSM-i-PRF/XBSM-i-PRF showed higher values compared to ABSM/XBSM with maximum values for ABSM-i-PRF and minimum values for XBSM. At days 3 and 7, the highest expression of AP was detected in ABSM-i-PRF/XBSM-i-PRF when compared to ABSM/XBSM, whereas at day 10, AP expression levels were elevated in ABSM-i-PRF/ABSM. The highest BMP-2 expression was seen in ABSM-i-PRF whereas OCN expression showed higher levels in ABSM-i-PRF/XBSM-i-PRF at days 3 and 7 with lowest expression for ABSM. Later on, elevated OC levels were detected for ABSM-i-PRF only. In conclusion, i-PRF in combination with ABSM enhances HOB activity when compared to XBSM-i-PRF or untreated BSM in vitro. Therefore, addition of i-PRF to ABSM and - to a lower extent - to XBSM may influence osteoblast activity in vivo.

Histological assessment of the effects of teriparatide therapy on mandibular fracture healing: A preclinical study

OBJECTIVE

This study was performed to evaluate the effects of teriparatide therapy on mandibular fracture healing in a rat model.

SUBJECTS AND METHODS

A unilateral mandibular fracture, 5 mm posterior to the last molar tooth, was surgically created in 120 rats. Half of the animals received a daily subcutaneous injection of 2 μg/kg teriparatide while the control rats received normal saline, starting from the day of surgery until sacrifice. Twenty rats from each group were sacrificed on postoperative days 10, 20, and 30. The healing process was evaluated histologically and scored using a grading system (ranging from 1 to 10).

RESULTS

On day 10 the fracture gaps of the control and teriparatide groups were mainly filled with fibrous tissue and new trabecular bone, respectively. On day 20 a large amount of new trabecular bone and some areas of fibrocartilaginous tissue were seen in the fracture gaps of the control rats. In the teriparatide group the fracture area was entirely filled with trabecular bone, which in some areas had been replaced by mature bone. On day 30 the fracture gaps of the control group were entirely bridged by new trabecular bone, while in the teriparatide group they was predominantly filled with mature bone. At all three time-points the mean healing scores for the teriparatide group (6.20 ± 0.70, 8.50 ± 0.69, and 9.85 ± 0.37, respectively) were significantly higher (p < 0.001) than for the control group (4.90 ± 0.55, 7.15 ± 0.59, and 8.90 ± 0.64, respectively).

CONCLUSION

Based on the results of this study, teriparatide should be tested in humans in order to establish whether comparable results can be achieved.