Plasma rich in growth factors in human extraction sockets: a radiographic and histomorphometric study on early bone deposition

Volumetric evaluation of effects of platelet-rich fibrin and concentrated growth factor on early bone healing after endodontic microsurgery: a randomized controlled trial

BACKGROUND

This randomized controlled clinical trial compared the effects of platelet-rich fibrin (PRF) and concentrated growth factor (CGF) on early bone healing after endodontic microsurgery.

METHODS

Eighteen patients with an isolated periapical lesion < 10 mm in the maxillary anterior region were randomly assigned to three groups: control, PRF, or CGF. Endodontic microsurgery was performed and PRF or CGF membranes were placed over the bone defects in the experimental groups. The volume of the bone defect at postoperative one week, three months, and six months was evaluated using cone-beam computed tomography and Mimics software. The results were statistically analyzed using the Kruskal-Wallis test and post-hoc Mann-Whitney U test with Bonferroni correction.

RESULTS

At the three-month follow-up, the PRF and CGF groups showed significantly greater bone healing compared with the control group (p > 0.05). However, no significant difference was observed between the PRF and CGF groups. At the six-month follow-up, no significant differences were observed between the groups.

CONCLUSIONS

These results suggested that PRF and CGF promote early bone healing after endodontic microsurgery.

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

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

Unravelling Alveolar Bone Regeneration Ability of Platelet-Rich Plasma: A Systematic Review with Meta-Analysis

Background: This systematic review aims to evaluate the efficacy of the available platelet-rich plasma (PRP) products and composition to regenerate alveolar bone after tooth extraction. Methods: PubMed, Cochrane Central Register of Controlled Trials, and EBSCO databases were searched up to 2 July 2021. Only randomized clinical trials using leukocyte-rich plasma (L-PRP) or pure-platelet rich plasma (P-PRP) for bone regeneration in alveolar ridge preservation were selected. The following outcomes were considered: (1) new bone formation (primary outcome) and (2) bone density (secondary outcome). A meta-analysis for PRP, P-PRP, and L-PRP using a fixed effect model was performed with Review Manager 5.4 software. Overall evidence was qualified using GRADE. Results: Six randomized clinical trials from 2639 unique articles initially identified met the inclusion criteria. The meta-analysis showed a significant effect of the P-PRP on the outcome of new bone formation (SMD, 1.44; 95% CI, 0.84 to 2.03) for P-PRP treatment. No information was retrieved for L-PRP. A statistically significant difference was also observed in the P-PRP group for bone density outcome (SMD, 1.24; 95% CI, 0.81 to 1.68). The L-PRP treated sockets also showed higher bone density (SMD, 0.88; 95% CI, 0.31 to 1.45) in comparison to control sockets. The quality of evidence was moderate for both outcomes in the P-PRP group and low for the L-PRP group. Conclusions: Despite the limitations of the included studies, our data suggest that P-PRP, in comparison to unassisted healing, can improve alveolar bone regenerative potential. However, more high-quality clinical studies are needed.

Platelet rich plasma in oral and maxillofacial surgery from the perspective of composition

The application of platelet-rich plasma (PRP) in oral and maxillofacial surgery has been thoroughly studied in the last two decades. Currently, different types of PRP are applied in the clinical practice, being the presence or absence of leukocytes one of the classification criteria. However, there is poor evidence assessing the influence of the PRP composition in their efficacy. In this context, the aim of this narrative review is to compile the existing evidence covering the efficacy of PRP in oral and maxillofacial surgery, starting from a systematic literature search and to qualitatively describe the efficacy outcomes from the composition perspective. According to the results of this review, the application of PRP in oral and maxillofacial surgery is a potential strategy to improve soft- and hard-tissue regeneration, observing differences in the efficacy of PRP depending on its composition and the studied application. P-PRP (the absence of leukocytes) has been more consistent in achieving beneficial effects in alveolar ridge preservation, management of post-extraction complications, bone augmentation and temporomandibular joint disorders. For that, the composition and methodology used to prepare the PRP should be a critical point when evaluating the efficacy of PRP.

Bone marrow aspirate concentrate and platelet-rich fibrin in fresh extraction sockets: A histomorphometric and immunohistochemical study in humans

The aim of this study was to evaluate the level of mineralized tissue and expression of bone markers in sockets grafted with platelet-rich fibrin and bone marrow aspirate concentrate (BMAC). Patients requiring extraction of one maxillary anterior tooth were randomized into three groups. After tooth extraction, the sockets in the control group (CG) were permitted to fill with blood clot. In the platelet-rich fibrin group (PRFG), after blood processing, the sockets were grafted with PRF plug. In the bone marrow aspirate concentrate combined with platelet-rich fibrin group (BM/PG), after blood and bone marrow processing, the sockets were grafted with a mixture of PRF plug and BMAC. After 6 months, the sites were reopened and bone cores were harvested and prepared for histomorphometric and immunohistochemical evaluation. The following levels were measured: mineralized tissue, expression of RUNX-2, and osteocalcin. Fifteen patients were included in this study. The histomorphometric analysis showed a more pronounced level of mineralized tissue in PRFG and BM/PG (54.20 ± 4.31% and 64.70 ± 6.74%, respectively) when compared with CG (40.60 ± 5.98%) (p = 0.0283 and p = 0.0090, respectively). The expression of RUNX-2 was very low in BM/PG (0.80 ± 0.84%) and absent in CG and PRFG (p = 0.0528). Osteocalcin expression was higher for BM/PG (23.40 ± 1.52%) when compared with CG and PRFG (18.40 ± 2.07% and 16.20 ± 1.92%, respectively) (p = 0.0117 and p = 0.0088, respectively). This preliminary study indicates that clinical use of bone marrow aspirate concentrate, when combined with platelet-rich fibrin as a carrier, might have some potential to increase mineralization in fresh extraction sockets.

Effects of Autologous Platelet-Rich Fibrin in Post-Extraction Alveolar Sockets: A Randomized, Controlled Split-Mouth Trial in Dogs with Spontaneous Periodontal Disease

Simple Summary

The effects of autologous platelet-rich fibrin were evaluated in dogs with spontaneous periodontal disease after tooth extraction. Both radiographic and histological findings attributed to the platelet-rich fibrin a potential ability to stimulate the natural process of tissue healing and regeneration of bone and soft tissues. Platelet-rich fibrin could, therefore, be considered as a simple and effective therapeutic aid in the management of post-extraction socket healing in dogs.

Abstract

Periodontal disease (PD) is a common inflammatory condition in dogs; in severe stages, dental extraction is frequently required. Platelet-rich fibrin (PRF) has been used in human oral surgical procedures and has been experimentally tested on post-extraction sockets in healthy dogs. This is the first split-mouth, randomized, controlled trial designed to compare post-extractive alveolar socket healing with and without topical application of PRF in canine spontaneous PD. Clinical evaluation, radiographic density, and histological scores for inflammation and regeneration were assessed at recruitment (T0) and after a three-week follow up (T1) on 12 dogs, for a total of 31 pairs of sockets. No complications or clinically evident differences between the treated sites and the control sites were observed. Comparing the radiographic densities of the extraction sites measured at T0 and T1, a significant enhancement was observed within the PRF group, but not within control group. The histological score decreased significantly from T0 to T1 within group PRF, but not within the control group; at T1, the PRF group showed a significantly lower histological score than the control group. These findings suggest that PRF could be able to stimulate the natural process of tissue healing and regeneration of post-extraction sites in dogs with spontaneous periodontal disease (PD).

The use of plasma rich in growth factors (PRGF) in guided tissue regeneration and guided bone regeneration. A review of histological, immunohistochemical, histomorphometrical, radiological and clinical results in humans

BACKGROUND

Modern surgeries have advanced toward personalized minimal-invasive treatments with a high rate of clinical healing that facilitates the regeneration of tissues. One of the leading approaches to deliver endogenous plasma- and platelet-derived growth factors is the plasma rich in growth factors (PRGF). This narrative review determines the effects of using PRGF in different oral surgical procedures including alveolar ridge augmentation, socket preservation, sinus floor augmentation and periodontal regeneration.

METHODS

For this narrative review, a literature search was conducted using PubMed and Researchgate. A combination of the following text words was used to maximize search specificity and sensitivity: "platelet-rich plasma", "PRP", "PRGF", "Platelet-rich growth factor", "socket preservation", "Extraction", "infra-bony pockets", "sinus floor augmentation", "randomized clinical controlled trials", "Alveolar osteitis", "Periodontal regeneration", "guided bone regeneration", "guided tissue regeneration".

RESULTS

Investigations have generally agreed that PRGF can promote and accelerate the healing process. PRGF optimizes the patient's quality of life by reducing pain, swelling and inflammation rate and also accelerates regeneration of soft tissue and bone tissue regeneration as well.

CONCLUSIONS

There is increasing evidence to support the use of PRGF in oral surgical procedures in order to improve the healing processes of the oral soft and hard tissues.

Platelet-rich fibrin to preserve alveolar bone sockets following tooth extraction: A randomized controlled trial

BACKGROUND

Platelet-rich fibrin (PRF) can be used in the alveolar socket preservation (ARP). However, the hard tissue-regeneration property of PRF in alveolar socket preservation is still unclear.

PURPOSE

To compare the new bone formation ratio between using PRF as a socket preservation material and normal wound healing, by means of histomorphometric analysis.

MATERIALS AND METHODS

Thirty-three healthy volunteers were recruited and randomized into PRF and control group. Minimally traumatic extractions were performed. Eighteen patients were treated with ARP using PRF, while the rest were left to heal naturally. Bone specimens were harvested using trephine bur 2 months after the extraction process. Histomorphometric analysis of new bone formation area compared with total socket area was performed using the software Fiji Is Just Image J (version 2, GNU General Public License).

RESULTS

Thirty-three volunteers were participated. Twenty-eight bone specimens were collected. The new bone formation ratio was higher in PRF group than in control group (31.33 ± 18% and 26.33 ± 19.63%, respectively). However, there was no statistically significant difference in the ratio between the PRF and control groups (P = .431).

CONCLUSIONS

It may be concluded that the use of PRF in ARP does not statistically significant enhance new bone formation after tooth extraction compared to normal wound healing (P > .05).

PRGF as adjunct to DBB in maxillary sinus floor augmentation: histological results of a pilot split-mouth study

Background

Various technologies of autologous blood concentrates are currently evaluated for their potential to enhance bone formation.

Aim

To report on the histological outcome of maxillary sinus floor augmentation (MSFA) with deproteinized bovine bone (DBB) in combination with chair-side prepared autologous platelet-rich growth factor (PRGF), in comparison to that with DBB alone.

Materials and methods

Six partially edentulous patients with ≤ 3-mm residual bone height bilaterally in the posterior maxilla were subjected to MSFA with the lateral window technique, using DBB in combination with PRGF (PRGF System1 Vitoria, Spain) on one side or DBB alone on the contralateral side. Cylindrical biopsies from the augmented sinuses were collected during implant installation, ca. 6 months post-MSFA, and subjected to non-decalcified histological and histomorphometric evaluation.

Results

The collected biopsies varied in length (range 3.5–9.9 mm); consequently, the portion of the biopsy representing augmented tissues also varied (range 2.3–14.6 mm²). New bone formation with a trabecular appearance and numerous DBB particles in contact with the new bone or with loose connective tissue were observed. No differences in the relative volumes of bone formation were found in sinuses augmented with DBB + PRGF or DBB alone 6 months after MSFA (35.6 ± 8.26 mm and 37.8 ± 3.15 mm, respectively).

Conclusion and clinical implications

In conclusion, based on these preliminary results, PRGF as adjunct to DBB for MSFA, except from improved handling during the operation, does not appear to enhance nor interfere with bone formation inside the human sinus 6 months after MSFA, compared with the use of DBB alone.

The use of platelet-rich plasma to enhance the outcomes of implant therapy: A systematic review

Objective

To assess the effect of platelet‐rich plasma (PRP) on implant dentistry. The primary focused question was as follows: What are the clinical, histological, and radiographic outcomes of PRP administration for bone regeneration and implant therapy?

Methods

A literature search was conducted involving three databases: MEDLINE, EMBASE and Cochrane database followed by a hand search of relevant scientific journals. Human studies using PRP for bone regeneration and implant therapy were considered and articles published up to December 31, 2017 were included. Eligible studies were selected based on the inclusion criteria, and quality assessments were conducted.

Results

In total, out from the 9,497 titles meeting the original search criteria, 22 fulfilled the inclusion criteria and were chosen for data extraction. Among them were 15 randomized controlled trials (RCT) and seven controlled clinical trials (CCT). Overall, the risk of bias was moderate to high. A total of seven studies showed superior outcomes when PRP was added during sinus floor elevation and five showed no superior outcome. Three studies found a significant advantage of PRP for alveolar bone regeneration and another three studies for soft tissue healing. Three studies reported on beneficial effects of PRP directly during implant placement while another study failed to find significant differences. Due to the heterogeneity of study designs, no meta‐analysis could be performed.

Summary and Conclusions

Despite the lack of consistent evidence supporting the clinical benefit of PRP in healthy patients, PRP might have a positive effect on wound healing and bone regeneration in compromised patients.

Plasma rich in growth factors (PRGF) in intraoral bone grafting procedures: A systematic review

PURPOSE

This systematic review aimed at assessing the effects of PRGF in new bone formation, soft tissue healing and post-operative pain and swelling in sites that underwent ridge preservation, ridge augmentation and maxillary sinus augmentation procedures.

MATERIALS AND METHODS

A comprehensive literature search employing seven databases was conducted by two independent reviewers. Only randomized and non-randomized controlled clinical trials using PRGF alone or in combination with bone grafting materials were selected.

RESULTS

Overall, 919 studies were identified, of which a total of 8 articles were included in the qualitative analysis. Two of the selected studies reported on ridge preservation, one on ridge augmentation and five on maxillary sinus augmentation. Positive results were recorded for soft tissue healing and post-operative pain and swelling following these procedures. However, outcomes of PRGF on new bone formation post extraction and on maxillary sinus augmentation when combined with other biomaterials were conflicting. Meta-analysis could not be conducted for any variables due to the heterogeneity of selected studies.

CONCLUSION

Limited evidence exists on the effects of PRGF in different intraoral bone grafting procedures, with some benefit reported on soft tissue healing and post-operative symptomatology. As this platelet concentrate is commonly used in clinical practice, further research is needed to fully assess its clinical indications and effectiveness.

The Role of Autologous Platelet Concentrates in Alveolar Socket Preservation: A Systematic Review

Prevention of alveolar bone resorption after tooth extraction may be useful for implant rehabilitation of the edentulous site minimizing the future need for bone augmentation procedures. A number of studies have investigated the efficacy of autologous platelet concentrates for the preservation of the alveolar bone volume after tooth extraction. Although encouraging results have been published, the available data are still controversial. The aim of the present systematic review was to assess the effect of platelet concentrates on alveolar socket preservation after tooth extraction. A literature search was carried out up to September 2017 for prospective controlled trials in which a test group using exclusively a platelet concentrate was compared with a control group in which extraction sockets were left to heal spontaneously. Seven controlled clinical trials published between 2010 and 2016 were included. A total of 320 extractions (170 tests and 150 controls) in 190 patients was considered. A great heterogeneity was found in terms of study design, methodological aspects, and outcome evaluation. For this reason, a quantitative analysis followed by meta-analysis was not possible, and only a descriptive analysis on the role of platelet concentrates in alveolar socket preservation was carried out. There is growing evidence that platelet concentrates may be advantageously used in postextraction sites, mainly to improve soft tissue healing and to reduce postoperative symptoms. Data about their potential in preserving the alveolar bone volume are still scarce and controversial, although recently encouraging results have been presented using more reliable and accurate evaluation technologies, such as the computed tomography. Further, well-designed and methodologically standardized investigations are strongly demanded to reach a higher level of evidence on this topic.

Immediate post-extraction implants with or without pure platelet-rich plasma: a 5-year follow-up study

PURPOSE

The purpose of this study was comparison of clinical and radiographic outcomes of immediate post-extraction implants with or without the use of pure platelet-rich plasma (P-PRP) in the short- and medium-term follow-up.

METHODS

A retrospective analysis was performed to assess soft tissue healing, implant and prosthesis survival, marginal bone level changes and biological complications.

RESULTS

A total of 109 partially edentulous patients with 126 implants were included in this analysis. At 4-5 years after loading, cumulative survival rate in test group was 97.4% and in control group was 97.8%, with no significant differences. After 5 years of function, marginal bone loss (MBL) in test group was 0.8 ± 0.35 and 1.02 ± 0.27 mm for immediate and delayed loading, respectively, and in control group was 0.6 ± 0.16 and 0.8 ± 0.89 mm for immediate and delayed loading, respectively. No significant differences in MBL were observed intragroups and intergroups at any time point considered. Soft tissue healing score was significantly higher in test group compared to the control at 3 and 7 days after surgery, with significant differences.

CONCLUSIONS

P-PRP implant group showed a better soft tissue management and wound healing in the first 7 days after surgery compared to non-P-PRP implant group. In the medium-term follow-up, comparable clinical and radiographic outcomes were noticed between two groups.

Estimation of date of death through wound healing of an extraction socket: A case report

Surgical extraction of teeth due to dental pathologies is a relatively common procedure in modern man. The healing of the wound that results occurs in gradual and sequential stages, such that the analysis of this repair process can be very useful in forensic investigations on human remains. The following study reports on a particular case where the remodeling of a tooth socket allowed an estimation of the time that had elapsed from the day of the surgical extraction of the tooth to the time of death. The corpse was that of a woman of 34 years. It was in an advanced state of decomposition, as it was largely skeletonized. Macroscopic, radiographic, and histological examinations of the oral cavity showed the initial stages of alveolar bone remodeling of the first left mandibular molar, which was characterized by: (i) a small reduction in the vertical height of the vestibular surface with respect to the theoretical original position of the tooth; (ii) resorption of the intra-alveolar septum and lamina dura; and (iii) formation of new immature bone, which covered the entire inner surface of the socket. This study established that the subject died 13-42days after the tooth extraction. Knowing the date of the dental extraction provided by the police investigation, it was possible to provide an estimate of the date of death.

Healing of Postextraction Sockets Preserved With Autologous Platelet Concentrates. A Systematic Review and Meta-Analysis

PURPOSE

The true benefit of autologous platelet concentrates (APCs) for enhancing the healing of postextraction sites is still a matter of debate, and in recent years several clinical trials have addressed this issue. The purpose of this study was to determine the effectiveness of an APC adjunct in the preservation of fresh extraction sockets.

MATERIALS AND METHODS

An electronic search was performed on Medline, Embase, Scopus, and the Cochrane Central Register of Controlled Trials. Only controlled clinical trials or randomized clinical trials were included. Selected articles underwent risk-of-bias assessment. The outcomes were complications and adverse events, discomfort and quality of life, bone healing and remodeling assessed by histologic and radiographic techniques, and soft tissue healing.

RESULTS

Thirty-three comparative studies were included. Nine articles had a parallel design and 24 had a split-mouth design. Twenty studies were considered to have a low risk of bias and 13 were considered to have a high risk. Overall, 1,193 teeth were extracted from 911 patients. Meta-analysis showed that soft tissue healing, probing depth at 3 months, and bone density at 1, 3, and 6 months were statistically better for the APC group. Qualitative analysis suggested that APCs might be associated with a decrease in swelling and trismus. However, no relevant difference among groups was found for probing depth at 1 month, incidence of alveolar osteitis, acute inflammation or infection, percentage of new bone, and indirect measurement of bone metabolism.

CONCLUSION

APCs should be used in postextraction sites to improve clinical and radiographic outcomes such as bone density and soft tissue healing and postoperative symptoms. The actual benefit of APCs on decreasing pain in extraction sockets is still not quantifiable.

Platelet-Rich Plasma: A Study of the Variables that May Influence Its Effect on Bone Regeneration

BACKGROUND

Currently, the use of platelet-rich plasma in bone regeneration is a real option, although more than one opinion has alerted us to the absence of clinical benefits.

PURPOSE

Analysis of the factors able to modify the characteristics of the platelet preparation obtained by Curasan, Plasma Rich in Growth Factors (PRGF), Platelet Concentrate Collection System (PCCS) and SmartPrep systems, relating them to the type of clinical application and the final bone regeneration achieved.

MATERIALS AND METHODS

A search was conducted in PubMed using the keywords "platelet-rich plasma," "PRP," "platelet rich growth factors," and "oral bone regeneration." Four widely accepted protocols for the obtention of PRP (above) were analyzed. Any clinical studies with controls, using the four preparation protocols and with a 4 to 6 weeks follow-up period were compared. The protocols were also grouped according to the type of PRP application: PRP-alone, with bone, or with bone substitutes.

RESULTS

Bone regeneration was not achieved in any of the cases using PRP obtained by Curasan and PCCS systems, whereas PRP obtained by SmartPrep achieved it only in one in three published cases and PRGF in one in six.

CONCLUSION

Based on the poor results observed in current literature, the use of PRP in oral surgery cannot be recommended.

Platelet preparations in dentistry: How? Why? Where? When?

The aim of this article is to review the outcomes of platelet preparations in dentistry. A structured electronic search discovered 348 articles, which described the use of autologous platelet concentrates with a relevance to clinical dentistry. Among these articles, 220 articles investigated platelet rich plasma, 99 investigated platelet rich fibrin, 22 investigated plasma rich in growth factors and 7 investigated the use of concentrated growth factors. Several studies reported beneficial treament outcomes in terms of enhanced bone and soft tissue regeneration.