Effect of platelet-rich plasma on the healing of intrabony defects treated with Beta tricalcium phosphate and expanded polytetrafluoroethylene membranes

The Effect of Xenograft and Platelet-Rich Plasma in the Surgical Management of Intrabony Defects in Periodontitis Patients: A Systematic Review

When treating intrabony defects to regenerate periodontal structure, platelet-rich plasma (PRP) alone or in conjunction with various grafting materials, enamel matrix proteins, and barrier membranes have shown promising results. This evidence-based review aimed to systematically appraise the efficacy of xenograft in combination with PRP in the surgical treatment of periodontal intrabony defects in comparison to xenograft alone in terms of clinical and radiographic outcomes in adults with periodontitis. Electronic and manual data were searched exhaustively by 2 reviewers, including PubMed-Medline, Cochrane Central Register of Controlled Trials, Embase and Scopus from the earliest available date till January 31, 2023 without restriction on language. Randomized controlled clinical trials of either parallel or a split-mouth design and studies where xenograft and PRP were in the intervention group or as a comparator was included. After screening the articles, 3 studies were included. The current systematic review reveals that PRP used as an adjunct with a xenograft resulted in a significant reduction in pocket depth and greater clinical attachment level gain in comparison to xenograft alone. The analysis of the present review concludes that PRP in conjunction with xenograft for the treatment of intrabony defects shows promising outcomes. However, owing to the short follow-up time and heterogeneity of included studies, caution should be followed while using this material clinically.

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.

Tricalcium phosphate (-containing) biomaterials in the treatment of periodontal infra-bony defects: A systematic review and meta-analysis

OBJECTIVES

This study aimed to investigate the additional clinical benefit of tricalcium phosphate (TCP) (-containing) biomaterials compared to open flap debridement (OFD) in periodontal infra-bony defects.

DATA

A literature search was conducted in Pubmed, Embase and Cochrane library for entries published up to 14th July 2021. All randomized controlled trials (RCTs) that compared a TCP (-containing) material with OFD and studies that assessed a beta-TCP group alone, with vertical defect sites with PPD of ≥ 6 mm and/or presence of infra-bony defects of ≥ 3 mm and a minimum follow-up of 6 months were included. Risk of bias was assessed with the Oxford scale. The random-effects (RE) model was synthesized as differences between weighted average (MD) for probing pocket depth (PPD) and clinical attachment level (CAL) between TCP and OFD groups. An RE analysis was also performed for the beta-TCP group alone.

STUDY SELECTION

Data from 16 RCTs were included in the analysis. Six studies that represented 151 patients and sites were selected for meta-analysis. The overall MD with 95% CI at 6 months was calculated to be -0.47 [-0.83, -0.12; P = 0.0087] and -1.06 [-1.67, -0.46; P = 0.0006] for PPD and CAL, respectively. Whereas MD at 12 months for PPD and CAL was -0.89 [-1.54, -0.23; P = 0.0078] and -1.25 [-1.85, -0.66; P<0.0001], respectively. All results were in favor of TCP (-containing) group over OFD.

CONCLUSIONS

The results of the study suggest that the use of a TCP (-containing) material may have the potential for additional clinical improvement in PPD and CAL compared with OFD in infra-bony defects, given the limitations of the included evidence.

CLINICAL SIGNIFICANCE

The use of TCP as a bone graft substitute is becoming increasingly common. Therefore, it would be advantageous if an adjunctive benefit in the regeneration of infra-bony defects could be demonstrated to facilitate material selection.

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.

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.

Periodontal regeneration: a bibliometric analysis of the most influential studies

Aim: The aim of the present study is to identify the most influential research articles and their main characteristics in the specialty of periodontal regeneration. Materials & methods: The Web of Science database advance search was performed in the subject category of 'Dentistry, Oral surgery and medicine' from January 2004 to October 2018 to retrieve citations data. Results: The majority of the articles were published in journals dedicated to the specialty of periodontology. Among the top-cited articles most emphasized study types were randomized control trials (n = 25) and reviews (n = 20). Conclusion: The present bibliometric analysis provides comprehensive information regarding the contributions made in the advancement of regenerative periodontal research. The authors from developed countries and affiliated with interdisciplinary/multicenter institutions have predominantly contributed.

Autologous platelet concentrates for treating periodontal infrabony defects

BACKGROUND

Periodontal disease is a condition affecting tooth-supporting tissues (gingiva, alveolar bone, periodontal ligament, and cementum), with the potential of introducing severe adverse effects on oral health. It has a complex pathogenesis which involves the combination of specific micro-organisms and a predisposing host response. Infrabony defects are one of the morphological types of alveolar bone defects that can be observed during periodontitis. Recent approaches for the treatment of infrabony defects, combine advanced surgical techniques with platelet-derived growth factors. These are naturally synthesized polypeptides, acting as mediators for various cellular activities during wound healing. It is believed that the adjunctive use of autologous platelet concentrates to periodontal surgical procedures produces a better and more predictable outcome for the treatment of infrabony defects.

OBJECTIVES

To assess the effects of autologous platelet concentrates (APC) used as an adjunct to periodontal surgical therapies (open flap debridement (OFD), OFD combined with bone grafting (BG), guided tissue regeneration (GTR), OFD combined with enamel matrix derivative (EMD)) for the treatment of infrabony defects.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 27 February 2018); the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 1) in the Cochrane Library (searched 27 February 2018); MEDLINE Ovid (1946 to 27 February 2018); Embase Ovid (1980 to 27 February 2018); and LILACS BIREME Virtual Health Library (from 1982 to 27 February 2018). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials on 27 February 2018. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of both parallel and split-mouth design, involving patients with infrabony defects requiring surgical treatment. Studies had to compare treatment outcomes of a specific surgical technique combined with APC, with the same technique when used alone.

DATA COLLECTION AND ANALYSIS

Two review authors independently conducted data extraction and risk of bias assessment, and analysed data following Cochrane methods. The primary outcomes assessed were: change in probing pocket depth (PD), change in clinical attachment level (CAL), and change in radiographic bone defect filling (RBF). We organised all data in four groups, each comparing a specific surgical technique when applied with the adjunct of APC or alone: 1. APC + OFD versus OFD, 2. APC + OFD + BG versus OFD + BG, 3. APC + GTR versus GTR, and 4. APC + EMD versus EMD.

MAIN RESULTS

We included 38 RCTs. Twenty-two had a split-mouth design, and 16 had a parallel design. The overall evaluated data included 1402 defects. Two studies were at unclear overall risk of bias, while the remaining 36 studies had a high overall risk of bias.1. APC + OFD versus OFD alone Twelve studies were included in this comparison, with a total of 510 infrabony defects. There is evidence of an advantage in using APC globally from split-mouth and parallel studies for all three primary outcomes: PD (mean difference (MD) 1.29 mm, 95% confidence interval (CI) 1.00 to 1.58 mm; P < 0.001; 12 studies; 510 defects; very low-quality evidence); CAL (MD 1.47 mm, 95% CI 1.11 to 1.82 mm; P < 0.001; 12 studies; 510 defects; very low-quality evidence); and RBF (MD 34.26%, 95% CI 30.07% to 38.46%; P < 0.001; 9 studies; 401 defects; very low-quality evidence).2. APC + OFD + BG versus OFD + BG Seventeen studies were included in this comparison, with a total of 569 infrabony defects. Considering all follow-ups, as well as 3 to 6 months and 9 to 12 months, there is evidence of an advantage in using APC from both split-mouth and parallel studies for all three primary outcomes: PD (MD 0.54 mm, 95% CI 0.33 to 0.75 mm; P < 0.001; 17 studies; 569 defects; very low-quality evidence); CAL (MD 0.72 mm, 95% CI 0.43 to 1.00 mm; P < 0.001; 17 studies; 569 defects; very low-quality evidence); and RBF (MD 8.10%, 95% CI 5.26% to 10.94%; P < 0.001; 11 studies; 420 defects; very low-quality evidence).3. APC + GTR versus GTR alone Seven studies were included in this comparison, with a total of 248 infrabony defects. Considering all follow-ups, there is probably a benefit for APC for both PD (MD 0.92 mm, 95% CI -0.02 to 1.86 mm; P = 0.05; very low-quality evidence) and CAL (MD 0.42 mm, 95% CI -0.02 to 0.86 mm; P = 0.06; very low-quality evidence). However, given the wide confidence intervals, there might be a possibility of a slight benefit for the control. When considering a 3 to 6 months and a 9 to 12 months follow-up there were no benefits evidenced, except for CAL at 3 to 6 months (MD 0.54 mm, 95% CI 0.18 to 0.89 mm; P = 0.003; 3 studies; 134 defects). No RBF data were available.4. APC + EMD versus EMDTwo studies were included in this comparison, with a total of 75 infrabony defects. There is insufficient evidence of an overall advantage of using APC for all three primary outcomes: PD (MD 0.13 mm, 95% CI -0.05 to 0.30 mm; P = 0.16; 2 studies; 75 defects; very low-quality evidence), CAL (MD 0.10 mm, 95% CI -0.13 to 0.32 mm; P = 0.40; 2 studies; 75 defects; very low-quality evidence), and RBF (MD -0.60%, 95% CI -6.21% to 5.01%; P = 0.83; 1 study; 49 defects; very low-quality evidence).All studies in all groups reported a survival rate of 100% for the treated teeth. No complete pocket closure was reported. No quantitative analysis regarding patients' quality of life was possible.

AUTHORS' CONCLUSIONS

There is very low-quality evidence that the adjunct of APC to OFD or OFD + BG when treating infrabony defects may improve probing pocket depth, clinical attachment level, and radiographic bone defect filling. For GTR or EMD, insufficient evidence of an advantage in using APC was observed.

Adjunctive Platelet-Rich Plasma (PRP) in Infrabony Regenerative Treatment: A Systematic Review and RCT's Meta-Analysis

Background and Objective

The purpose of this study was to highlight the clinical performance of platelet-rich plasma (PRP) used as an adjunctive tool for regeneration in infrabony periodontal defects using different biomaterials or performing different surgical flap approaches. Comparative evaluation of main clinical outcomes as probing pocket depth reduction, clinical attachment gain, and recession reduction with and without the use of PRP has been analysed.

Materials and Methods

According to the focused question, an electronic and hand searching has been performed up to December 2016. From a batch of 73 articles, the selection strategy and Jadad quality assessment led us to include 15 studies for the meta-analysis.

Results

Despite the high heterogeneity found and the lack of complete data regarding the selected clinical outcomes, a comparative analysis has been possible by the categorization of used biomaterials and surgical flap approaches. This method led us to observe the best performance of grafts with the use of adjunctive PRP in CAL gain and PPD reduction. No difference has been outlined with a specific surgical flap.

Conclusions

Although PRP is considered a cheap and patient's derived growth factor, the not conclusive data reported would suggest that its use in addition to bone substitutes could be of some clinical benefit in the regenerative treatment of infrabony defects.

Clinical Relevance

This systematic review was intended to sort out the huge controversial debate in the field about the possible use of PRP in regenerative surgery in infrabony defect. The clinical relevance of using blood-borne growth factors to conventional procedures is effective as these could determine a better performance and outcomes despite the surgical approach adopted and limit the use of additional biomaterials for the blood clot stabilization.

Influence of autogenous platelet concentrate on combined GTR/graft therapy in intra-bony defects: A 13-year follow-up of a randomized controlled clinical split-mouth study

AIM

To investigate the clinical long-term outcomes 13 years following guided tissue regeneration (GTR) in deep intra-bony defects with and without additional application of autogenous platelet concentrate (APC).

METHODS

In 25 patients, two deep contra-lateral intra-bony defects were treated according to GTR using β-TCP and bio-resorbable membranes. In test defects, APC was applied additionally. After 13 years, clinical healing results were assessed and compared to results at baseline and after 1 year. Furthermore, a tooth survival analysis was carried out.

RESULTS

After 13 years, 22 patients were available for tooth survival analysis showing 81.8% of test and 86.4% of control teeth still in situ. Based on the 15 patients still available for split-mouth analysis, median CAL was 10.0 mm in test and 12.0 mm in control sites at baseline. After 1 year, both groups revealed significant CAL gains of 5.0 mm, followed by a new CAL loss of 1.0 mm in the following 12 years. There were no significant differences between test and control sites.

CONCLUSION

Within the limits of this study, the data show that most of the CAL gain following GTR can be maintained over 13 years. The additional use of APC had no positive influence on the long-term stability.

Adjunctive Effect of Autologus Platelet-Rich Fibrin to Barrier Membrane in the Treatment of Periodontal Intrabony Defects

BACKGROUND AND AIM

Autologous platelet-rich fibrin (PRF) and barrier membranes in the treatment of intrabony defects in chronic periodontitis patients have shown significant clinical benefits. This study evaluates the additive effect of autologous PRF in combination with a barrier membrane versus the use of barrier membrane alone for the treatment of intrabony defects in chronic periodontitis patients.

METHODS

A randomized split-mouth design was used. Sixteen patients with 32 paired intrabony defects were included. In each patient 1 defect was treated using a resorbable collagen membrane along with PRF (test group) and the other defect by guided tissue regeneration alone (control group). The following clinical parameters were measured at baseline and after 9 months: plaque index, modified sulcus bleeding index, probing pocket depth, clinical attachment level, and gingival marginal level. The radiographic defect depth was also assessed at baseline and after 9 months.

RESULTS

Test group showed a statistically significant improvement for probing depth (P = 0.002), clinical attachment level (P = 0.001), and radiographic defect depth (P < 0.001) after 9 months as compared with the control sites. Radiographic defect depth reduction was 58.19 ± 13.24% in the test group as compared with 24.86 ± 9.94% reduction in the control group.

CONCLUSIONS

The adjunctive use of PRF in combination with barrier membrane is more effective in the treatment of intrabony defects in chronic periodontitis as compared with barrier membrane alone.

Guided tissue regeneration and platelet rich growth factor for the treatment of Grade II furcation defects: A randomized double-blinded clinical trial - A pilot study

Background

The treatment of furcation area defects remained as a challenging issue in periodontal treatments. Regeneration treatment of furcation defects is the most discussed periodontal treatment. Although not completely hopeless in prognosis, the presence of the furcation involvement significantly increases the chance of tooth loss. The current research was conductedeto compare theeadditive effect of combined guided tissue regeneration (GTR) and platelet-rich growth factor (PRGF) on the treatment of furcation bony defects.

Materials and Methods

A randomized, triple-blinded, split-mouth study was designed. It included patients with a moderate to severe chronic periodontitis with bilateral Grade II furcation involvement of first or second mandibular molars. Each side of mouth was randomly allocated for the treatment with either Bio-Gide American Society of Anesthesiologists GTR or a PRGF or PRGF by itself. Plaque index, gingival index, vertical clinical attachment level, vertical probing depth, recession depth (REC), horizontal probing depth, fornix to alveolar crest (FAC), fornix to base of defect (FBD), furcation vertical component and furcation horizontal component (FHC) were recorded. The current research was conducted to compare the additive effect of combined GTR and PRGF on treatment of furcation bony defects. Altman's nomogram, Kolmogorov-Smirnov test, Friedman test, general linear model, repeated measures, and paired t-test were used as statistical analysis in this research. P < 0.05 was considered statistically significant.

Results

Eight patients were finally enrolled for this study. Overly, general and specific clinical and furcation parameters were improved except REC that was deteriorated insignificantly and FAC improved not significantly. Intergroup comparison revealed better improvement of FHC in GTR/PRGF group (P = 0.02).

Conclusion

A significant improvement in the Grade II furcation defects treated with either GTR or PRGF/GTR was noticed. Further large-scale trials are needed to reveal differences of mentioned treatment in more details.

The effect of platelet-rich plasma on clinical outcomes of the surgical treatment of periodontal intrabony defects: A systematic review and meta-analysis

Background

Studies investigating the use of platelet–rich plasma (PRP) in the treatment of intrabony defects have yielded mixed results. The aim of our study was to evaluate the efficacy of PRP by comparing clinical attachment level (CAL) and pocket depth (PD) for patients who received PRP as an adjunct to periodontal intrabony defect therapy with those for patients who did not. We also analyzed the influence of guided tissue regeneration (GTR) and different study designs (parallel and split–mouth studies) on the clinical outcomes of intrabony defects.

Methods

We performed a systematic review of articles published in any language up to June 7, 2015 by searching PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. We included only randomized controlled clinical trials (RCTs) that compared clinical outcomes between patients who received PRP as an adjunct to periodontal intrabony defect therapy and patients who did not. We combined data from randomized trials to assess clinical outcomes using a random–effects model.

Results

Of the 307 abstracts that were initially identified, 12 RCTs related to the treatment of periodontal intrabony defects were included in the final analysis. Clinically and significantly greater CAL gains and PD reductions were observed in subjects who received PRP as an adjunct to periodontal intrabony defect therapy than in subjects who did not (CAL: WMD 0.76 mm, 95 % CI = 0.34 to 1.18 mm, P = 0.0004; PD: WMD 0.53 mm, 95 % CI = 0.21 to 0.85 mm, P = 0.001). Subgroup meta-analyses of patients who underwent GTR demonstrated that this approach did not significantly affect treatment outcomes (CAL: WMD 0.08 mm, 95 % CI = −0.30 to 0.46 mm, P = 0.67), as indicated by a comparison with patients who did not undergo GTR (CAL: WMD 1.22 mm, 95 % CI = 0.88 to 1.57 mm, P < 0.00001). Univariate meta-regression analyses revealed that the use of GTR explained the heterogeneity among the included studies (P < 0.05).

Conclusions

Within its limitations, this review suggests that PRP may be beneficial as an adjunct to graft materials for the treatment of periodontal intrabony defects, except in cases involving the use of GTR.

Surgical Treatment of Periodontal Intrabony Defects with Calcium Sulphate in Combination with Beta-Tricalcium Phosphate: Clinical Observations Two Years Post-Surgery

The study was designed to evaluate the clinical outcome of a composite material, beta-tricalcium phosphate in combination with calcium sulphate, in the treatment of periodontal intrabony defects. The combination of these materials is believed to aid in guided tissue regeneration owing to their properties. A total of 47 teeth with intrabony defects in 26 periodontitis patients were treated with Fortoss® Vital (Biocomposites, Staffordshire, UK). Clinical parameters were evaluated which included changes in probing depth, clinical attachment level/loss and gingival recession at the baseline and 2 years postoperatively. The mean differences in measurements between the baseline and 2 years postoperatively were a reduction of 2.07±1.14 mm (p=0.000) in case of probing depth and a gain of 1.93±1.36 mm (p=0.000) in clinical attachment level; but an increase of 0.14±0.73 mm (p=0.571) in gingival recession. The study results show that the treatment with a combination of beta tricalcium phosphate and calcium sulphate led to a significantly favorable clinical improvement in periodontal intrabony defects 2 years after the surgery.

Comparative evaluation of clinical efficacy of β-tri calcium phosphate (Septodont-RTR)™ alone and in combination with platelet rich plasma for treatment of intrabony defects in chronic periodontitis

Aim:

To assess the clinical outcome by comparing β-tri calcium phosphate (Septodont RTR)™ along with platelet rich plasma (PRP) and β-tri calcium phosphate (β-TCP) alone in intrabony defects, by clinical evaluation in a 6-month analysis.

Methodology:

Ten patients participated in the study. Using a split-mouth design, interproximal bony defects were surgically treated with either platelet rich plasma (PRP) combined with β-tri calcium phosphate (β-TCP) or β-TCP alone. Plaque Index (PI), Gingival Index, Probing Pocket Depth (PPD), Clinical Attachment Level (CAL) were recorded 6 months after surgery.

Results:

At 6 months after therapy, the PRP combined with β-TCP group showed mean PPD reduction of 2.50, CAL mean gain of 2.60 + 1.43. The β-TCP group showed mean PPD reduction of 2.80 mm, mean CAL gain of 2.60 mm. On intra-group comparison, there was greater PPD reduction and CAL gain at 6 months in both the groups. In intergroup comparison of PRP/β-TCP and β-TCP alone, there was no statistical significant difference observed. (P = 0.55, and 0.87 for PPD and CAL gain).

Conclusion:

Both therapies resulted in significant PPD reduction, CAL gain. The present study shows that treatment of intrabony periodontal defects with combination of PRP and β-TCP does not have additional improvements when compared with β-TCP alone within 6 months follow-up.

Long-term clinical results on the use of platelet concentrate in the treatment of intrabony periodontal defects

OBJECTIVE

The purpose of this clinical investigation was to evaluate long-term results obtained with the combination of platelet pellet (PP) plus bioabsorbable barrier membrane (BM) and to compare this outcome with the results obtained using bioactive glass (BG) graft material with a BM.

MATERIALS AND METHODS

Using a split mouth design, 11 chronic periodontitis patients (power ≥ at least 80%) were randomly assigned to treatment with a combination of PP/GTR or BG/GTR in contra-lateral dentition areas. Clinical attachment level (CAL) as the primary outcome variable, calculated as the sum of probing pocket depth (PPD) and gingival recession, and radiological alveolar bone level were recorded at baseline, 6 months and 5 years.

RESULTS

There were no statistical differences between test and control defects at baseline. PPD reductions and CAL and radiological alveolar bone height gains were statistically significant between baseline and 6 months and between baseline and 5 years in both groups (p < 0.01). Six months results of frequency distribution showed that 82% of the defects attained ≥ 4 mm CAL gain in both groups, while 5 year results showed that 73% of the defects attained 2 mm ≤ CAL gain < 4 mm in the PP/BM group and 55% of the defects attained 2 mm ≤ CAL gain < 4 mm in the BG/BM group. All parameters evaluated showed no significant differences between 6 months and 5 years in both groups (p > 0.05). No statistically significant difference in any of the clinical parameters was observed at 6 months and 5 years between the groups (p > 0.05).

CONCLUSIONS

The long-term efficacy of platelet concentrate combined with a barrier membrane is similar with the combination of bioactive glass graft material and barrier membrane, suggesting that results obtained with both treatment approaches can be maintained over a period of 5 years.

Does PRP enhance bone integration with grafts, graft substitutes, or implants? A systematic review

Background

Several bone implants are applied in clinical practice, but none meets the requirements of an ideal implant. Platelet-rich plasma (PRP) is an easy and inexpensive way to obtain growth factors in physiologic proportions that might favour the regenerative process. The aim of this review is to analyse clinical studies in order to investigate the role of PRP in favouring bone integration of graft, graft substitutes, or implants, and to identify the materials for which the additional use of PRP might be associated with superior osseo- and soft tissues integration.

Methods

A search on PubMed database was performed considering the literature from 2000 to 2012, using the following string: ("Bone Substitutes"[Mesh] OR "Bone Transplantation"[Mesh] OR "Bone Regeneration"[Mesh] OR "Osseointegration"[Mesh]) AND ("Blood Platelets"[Mesh] OR "Platelet-Rich Plasma"[Mesh]). After abstracts screening, the full-texts of selected papers were analyzed and the papers found from the reference lists were also considered. The search focused on clinical applications documented in studies in the English language: levels of evidence included in the literature analysis were I, II and III.

Results

Literature analysis showed 83 papers that fulfilled the inclusion criteria: 26 randomized controlled trials (RCT), 14 comparative studies, 29 case series, and 14 case reports. Several implant materials were identified: 24 papers on autologous bone, 6 on freeze-dried bone allograft (FDBA), 16 on bovine porous bone mineral (BPBM), 9 on β-tricalcium phosphate (β-TCP), 4 on hydroxyapatite (HA), 2 on titanium (Ti), 1 on natural coral, 1 on collagen sponge, 1 on medical-grade calcium sulphate hemihydrate (MGCSH), 1 on bioactive glass (BG) and 18 on a combination of biomaterials. Only 4 papers were related to the orthopaedic field, whereas the majority belonged to clinical applications in oral/maxillofacial surgery.

Conclusions

The systematic research showed a growing interest in this approach for bone implant integration, with an increasing number of studies published over time. However, knowledge on this topic is still preliminary, with the presence mainly of low quality studies. Many aspects still have to be understood, such as the biomaterials that can benefit most from PRP and the best protocol for PRP both for production and application.

Tissue engineering: A new vista in periodontal regeneration

Tissue engineering is a highly promising field of reconstructive biology that draws on recent advances in medicine, surgery, molecular and cellular biology, polymer chemistry, and physiology. The objective of using tissue engineering as therapeutic application has been to harness its ability to exploit selected and primed cells together with an appropriate mix of regulatory factors, to allow growth and specialization of cells and matrix. The authors reviewed controlled clinical trials which also included histological studies that evaluated the potential of tissue engineering as a clinical tool in regeneration. PubMed/MEDLINE databases were searched for studies up to and including June 2010 to identify appropriate articles. A comprehensive search was designed, and the articles were independently screened for eligibility. Articles with authentic controls and proper randomization and pertaining specifically to their role in periodontal regeneration were included. Studies demonstrated that the periodontal regeneration with the use of combination of tissue engineered products with an osteoconductive matrix improve the beneficial effect of these materials by accelerating cellular in growth and revascularization of the wound site. Studies have suggested the use of rh Platelet-derived growth factor + beta tricalcium phosphate for regeneration of the periodontal attachment apparatus in combination with collagen membranes as an acceptable alternative to connective tissue graft for covering gingival recession defects. The studies concluded that growth factors promote true regeneration of the periodontal attachment apparatus and the use of combination protein therapeutics which is commercially available can provide more predictable, faster, less invasive, less traumatic, and efficient outcome for the patient.

In vivo comparison of the bone regeneration capability of human bone marrow concentrates vs. platelet-rich plasma

BACKGROUND

Bone marrow aspirate concentrate (BMAC) including high densities of stem cells and progenitor cells may possess a stronger bone regenerative capability compared with Platelet-rich plasma (PRP), which contains enriched growth factors. The objective of this study was to evaluate the effects of human BMAC and PRP in combination with β-tricalcium phosphate (β-TCP) on promoting initial bone augmentation in an immunodeficient mouse model.

METHODOLOGY/PRINCIPAL FINDINGS

BMAC and PRP were concentrated with an automated blood separator from the bone marrow and peripheral blood aspirates. β-TCP particles were employed as a scaffold to carry cells. After cell counting and FACS characterization, three groups of nude mice (BMAC+TCP, PRP+TCP, and a TCP control) were implanted with graft materials for onlay placement on the cranium. Samples were harvested after 4 weeks, and serial sections were prepared. We observed the new bone on light microscopy and performed histomorphometric analysis. After centrifugation, the concentrations of nucleated cells and platelets in BMAC were increased by factors of 2.8 ± 0.8 and 5.3 ± 2.4, respectively, whereas leucocytes and platelets in PRP were increased by factors of 4.1 ± 1.8 and 4.4 ± 1.9, respectively. The concentrations of CD34-, CD271-, CD90-, CD105-, and CD146-positive cells were markedly increased in both BMAC and PRP. The percentage of new bone in the BMAC group (7.6 ± 3.9%) and the PRP group (7.2 ± 3.8%) were significantly higher than that of TCP group (2.7 ± 1.4%). Significantly more bone cells in the new bone occurred in sites transplanted with BMAC (552 ± 257) and PRP (491 ± 211) compared to TCP alone (187 ± 94). But the difference between the treatment groups was not significant.

CONCLUSIONS/SIGNIFICANCE

Both human BMACs and PRP may provide therapeutic benefits in bone tissue engineering applications. These fractions possess a similar ability to enhance early-phase bone regeneration.

Radiographic and histologic evaluation of platelet-rich plasma and bovine-derived xenograft combination in bilateral sinus augmentation procedure

There is currently a great interest regarding the use of platelet-rich plasma (PRP) in combination with various bone graft materials in sinus lift procedures. The purpose of this study was to assess and compare the radiographic and histological results of sinus augmentation procedures following treatment with PRP/bovine-derived xenograft (BDX) vs. BDX/collagen membrane. Using a split mouth design, 10 patients, with ≤5 mm of residual alveolar bone in the vertical direction, were treated with PRP/BDX or BDX/collagen membrane. At 8 months after surgery, both graft materials led to a satisfactory increase in vertical dimensions of bone. Bone biopsies were taken from the augmented sites during the implant placement. Histological analysis demonstrated that majority of the trabecula contained orderly layered lamellar bone in the PRP/BDX group, whereas mainly woven bone with a haphazard arrangement of collagen fibers were noticed in the BDX /collagen membrane group. It can be concluded that both combinations resulted with a satisfactory bone height, but more prominent and mature bone formation was observed at sites treated with PRP/BDX.

Treatment of intrabony defects with beta-tricalciumphosphate alone and in combination with platelet-rich plasma

BACKGROUND

The therapeutic efficacy of platelet-rich plasma (PRP) still remains controversial. This study aimed to compare the efficacy of a beta-tricalcium phosphate (β-TCP) and PRP/β-TCP combination both clinically and radiographically.

METHODS

Fourteen chronic periodontitis patients with at least two similar three-walled defects were included in the study. Each patient was randomly treated with both β-TCP (n = 14) and PRP/β-TCP (n = 14) in the same session. Baseline and 6-month evaluations of plaque index (PI), gingival index (GI), probing pocket depth (PPD), clinical attachment level (CAL), gingival recession (GR), bleeding on probing, and radiographic intrabony defect depth (RIDD) were assessed statistically.

RESULTS

At 6 months, statistically significant reductions of GI, PPD, BOP, and RIDD were observed in both groups. The median values of CAL decreased from 7.0 to 6.0 mm in the β-TCP group (p = 0.002), and 7.5 to 5.0 mm in the PRP/β-TCP group (p < 0.001). No statistically significant difference was detected between the two groups for all clinical indices.

CONCLUSION

After a 6-month healing period, both β-TCP and PRP/β-TCP were found effective in the treatment of three-walled intrabony defects and no additional statistically significant benefits were found with PRP.

Implant Installation With Simultaneous Ridge Augmentation. Report of Three Cases

The anatomic limitations of the residual alveolar bone may cause problems for the insertion of dental implants because implant placement requires an adequate quantity and quality of bone. Ridge augmentation has been performed to reconstruct alveolar ridges as support for the placement of dental implants with a high success rate. However, a staged approach requires multiple surgeries and more treatment time. In this report, the patients were treated with dental implantation with simultaneous ridge augmentation in both submerged and nonsubmerged cases. The prostheses were well in function without any probing depth or gingival inflammation up to final evaluation. It may be suggested that dental implantation with simultaneous bone grafting may be an option when the graft material can be well stabilized around the implants. Further evaluations over long periods of time are needed to monitor the clinical results.

The influence of hyperbaric oxygen treatment on the healing of experimental defects filled with different bone graft substitutes

To assess potential effects of hyperbaric oxygen (HBOT) on artificial bone grafts, β - Tricalcium phosphate (β-TCP) and calcium phosphate coated bovine bone (CPCBB) substitutes were applied to standard bone defects in rat tibiae. The control defects were left empty. Half of the animals received 60 minutes of 2.4 atmosphere absolute (ATA) of HBOT. Rats were sacrificed at one, two and four weeks. Bone healing was assessed histologically and histomorphometrically using light microscopy. The periosteum over the bone defects was examined ultrastructurally. Cardiac blood was collected to determine the serum osteocalcin levels. The HBOT increased new bone formation in the unfilled controls and β-TCP groups and significantly decreased cartilage matrix and fibrous tissue formations in all groups. Active osteoblasts and highly organized collagen fibrils were prominent in the periosteum of β-TCP and control groups. Serum osteocalcin levels also increased with HBOT. The healing of defects filled with CPCBB was similar to the controls and it did not respond to HBOT. These findings suggested that the HBOT had beneficial effects on the healing of unfilled bone defects and those filled with β-TCP bone substitute but not with CPCBB, indicating a material-specific influence pattern of HBOT.

Is platelet concentrate advantageous for the surgical treatment of periodontal diseases? A systematic review and meta-analysis

BACKGROUND

The aim of the present review is to systematically evaluate the effects of autogenous platelet concentrates on clinical outcomes of the surgical treatment of periodontal diseases.

METHODS

MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched using a combination of specific search terms. Furthermore, a hand search of relevant journals and bibliographies of reviews was performed. Only randomized clinical trials were included. For periodontal intrabony defects, the primary outcome variable was the clinical attachment level. For gingival recession, outcome variables were root coverage and keratinized tissue increase. Data were adjusted for baseline values. The methodologic quality of the included studies was assessed. The results of studies in which the only difference between test and control groups was the adjunct of platelet concentrates were aggregated using a meta-analysis. For intrabony defects, the influences of guided tissue regeneration (GTR) and study type (split-mouth versus parallel studies) were also evaluated.

RESULTS

The initial search yielded 424 studies. Of the 29 eligible studies, 24 studies were included. There were 16 studies on the treatment of periodontal intrabony defects, all of which used platelet-rich plasma (PRP); six studies on gingival recession treatment; and two studies on the treatment of furcation defects. A significant positive effect of the adjunct of PRP was found for intrabony defects. Such an effect was magnified in studies in which GTR was not used, whereas in studies using GTR, the use of PRP had no adjunctive effect. No effect of the study type was found. No significant effect of platelet concentrates was found for gingival recession treatment in which only studies with a follow-up ≤6 months displayed positive results. No significant benefit of PRP could be demonstrated for furcation treatment.

CONCLUSIONS

PRP may exert a positive adjunctive effect when used in combination with graft materials, but not with GTR, for the treatment of intrabony defects. No significant benefit of platelet concentrates was found for the treatment of gingival recession.

Treatment of intrabony periodontal defects with platelet-rich plasma versus platelet-poor plasma combined with a bovine-derived xenograft: a controlled clinical trial

BACKGROUND

The purpose of this study is to assess the healing outcomes of intrabony defects after treatment with platelet-rich plasma (PRP) versus platelet-poor plasma (PPP) combined with bovine-derived xenograft (BDX).

METHODS

Using a split-mouth design, a total of 79 intrabony defects with an intrabony component of ≥3 mm in 20 patients were treated either with PRP/BDX (group 1) or PPP/BDX (group 2). At baseline and 12 months after surgery, plaque and sulcus bleeding indices, probing depth (PD), relative attachment level, recession, and probing and radiographic bone levels were recorded.

RESULTS

After 12 months, groups 1 and 2 presented a mean PD reduction of 3.87 ± 0.86 and 3.76 ± 0.80 mm, recession of 1.35 ± 0.68 and 1.58 ± 0.54 mm, attachment gain of 2.51 ± 0.97 and 2.18 ± 0.87 mm, clinical bone gain of 2.18 ± 0.86 and 2.09 ± 0.89 mm, and radiographic bone gain of 2.11 ± 0.87 and 2.19 ± 0.96 mm, respectively. Intergroup differences were found to be insignificant.

CONCLUSIONS

Within its limits, these results suggest that the outcomes of the treatment after PRP/BDX and PPP/BDX applications in intrabony defects are similar. When the platelet counts are taken into consideration, PPP seems to demonstrate similar clinical efficacy as the PRP.

The effect of platelet-rich plasma (PRP) combined with a bone allograft on human periodontal ligament (PDL) cells

The prominent purpose of the study was the evaluation of the in vitro mitogenic effect of three different homologous platelet-rich plasma (PRP) preparations (PRPa, PRPb, PRPc) on three different lines of periodontal ligament (PDL) cells (PDL(1,2,3)), cultured alone or in combination with a demineralized freeze-dried allograft (DFBA). PDL cell cultures were derived from the mid root of three maxillary caries-free premolars extracted for orthodontic reasons. Cells were grown and reached confluence. To evaluate the mitogenic effect of all exogenous factors (PRPa, PRPb, PRPc and DFBA) on PDL cells, specific number of cells (10.000/well) was cultured in the presence or absence of the above factors. Each PRP preparation (5% v/v) was added in all cell lines, in the absence or presence of 10 mg/ml of DFBA. The cells were also treated with 25 ng/ml bFGF (positive control). The mitogenic effect was evaluated 24 h after incubation, using the Trypan blue exclusion assay. The results revealed that all PRP preparations act as potent mitogens as they significantly induced cell proliferation on PDL(1,2,3) lines. All PRP preparations when added alone in the PDL cell cultures, exhibited a significant advantage over the positive control (bFGF). The addition of DFBA to PRP did not influence significantly cell proliferation in all cell lines, comparatively to PRP alone, at the time -period studied. The findings of this study demonstrate the beneficial role of PRP alone or combined with the bone graft on periodontal ligament cells in vitro, suggesting that it may be considered as a potential biological approach in periodontal regeneration.

A review on endogenous regenerative technology in periodontal regenerative medicine

Periodontitis is a globally prevalent inflammatory disease that causes the destruction of the tooth-supporting apparatus and potentially leads to tooth loss. Currently, the methods to reconstitute lost periodontal structures (i.e. alveolar bone, periodontal ligament, and root cementum) have relied on conventional mechanical, anti-infective modalities followed by a range of regenerative procedures such as guided tissue regeneration, the use of bone replacement grafts and exogenous growth factors (GFs), and recently developed tissue engineering technologies. However, all current or emerging paradigms have either been shown to have limited and variable outcomes or have yet to be developed for clinical use. To accelerate clinical translation, there is an ongoing need to develop therapeutics based on endogenous regenerative technology (ERT), which can stimulate latent self-repair mechanisms in patients and harness the host's innate capacity for regeneration. ERT in periodontics applies the patient's own regenerative 'tools', i.e. patient-derived GFs and fibrin scaffolds, sometimes in association with commercialized products (e.g. Emdogain and Bio-Oss), to create a material niche in an injured site where the progenitor/stem cells from neighboring tissues can be recruited for in situ periodontal regeneration. The choice of materials and the design of implantable devices influence therapeutic potential and the number and invasiveness of the associated clinical procedures. The interplay and optimization of each niche component involved in ERT are particularly important to comprehend how to make the desired cell response safe and effective for therapeutics. In this review, the emerging opportunities and challenges of ERT that avoid the ex vivo culture of autologous cells are addressed in the context of new approaches for engineering or regeneration of functional periodontal tissues by exploiting the use of platelet-rich products and its associated formulations as key endogenous resources for future clinical management of periodontal tissue defects.

Periodontal tissue engineering and regeneration: current approaches and expanding opportunities

The management of periodontal tissue defects that result from periodontitis represents a medical and socioeconomic challenge. Concerted efforts have been and still are being made to accelerate and augment periodontal tissue and bone regeneration, including a range of regenerative surgical procedures, the development of a variety of grafting materials, and the use of recombinant growth factors. More recently, tissue-engineering strategies, including new cell- and/or matrix-based dimensions, are also being developed, analyzed, and employed for periodontal regenerative therapies. Tissue engineering in periodontology applies the principles of engineering and life sciences toward the development of biological techniques that can restore lost alveolar bone, periodontal ligament, and root cementum. It is based on an understanding of the role of periodontal formation and aims to grow new functional tissues rather than to build new replacements of periodontium. Although tissue engineering has merged to create more opportunities for predictable and optimal periodontal tissue regeneration, the technique and design for preclinical and clinical studies remain in their early stages. To date, the reconstruction of small- to moderate-sized periodontal bone defects using engineered cell-scaffold constructs is technically feasible, and some of the currently developed concepts may represent alternatives for certain ideal clinical scenarios. However, the predictable reconstruction of the normal structure and functionality of a tooth-supporting apparatus remains challenging. This review summarizes current regenerative procedures for periodontal healing and regeneration and explores their progress and difficulties in clinical practice, with particular emphasis placed upon current challenges and future possibilities associated with tissue-engineering strategies in periodontal regenerative medicine.

Toward delivery of multiple growth factors in tissue engineering

Inspired by physiological events that accompany the "wound healing cascade", the concept of developing a tissue either in vitro or in vivo has led to the integration of a wide variety of growth factors (GFs) in tissue engineering strategies in an effort to mimic the natural microenvironments of tissue formation and repair. Localised delivery of exogenous GFs is believed to be therapeutically effective for replication of cellular components involved in tissue development and the healing process, thus making them important factors for tissue regeneration. However, any treatment aiming to mimic the critical aspects of the natural biological process should not be limited to the provision of a single GF, but rather should release multiple therapeutic agents at an optimised ratio, each at a physiological dose, in a specific spatiotemporal pattern. Despite several obstacles, delivery of more than one GF at rates mimicking an in vivo situation has promising potential for the clinical management of severely diseased tissues. This article summarises the concept of and early approaches toward the delivery of dual or multiple GFs, as well as current efforts to develop sophisticated delivery platforms for this ambitious purpose, with an emphasis on the application of biomaterials-based deployment technologies that allow for controlled spatial presentation and release kinetics of key biological cues. Additionally, the use of platelet-rich plasma or gene therapy is addressed as alternative, easy, cost-effective and controllable strategies for the release of high concentrations of multiple endogenous GFs, followed by an update of the current progress and future directions of research utilising release technologies in tissue engineering and regenerative medicine.

Treatment of periodontal endosseous defects with platelet-rich plasma alone or in combination with demineralized freeze-dried bone allograft: a comparative clinical trial

BACKGROUND

Platelet-rich plasma (PRP) alone or combined with other regenerative materials was previously studied in human periodontal endosseous defects. There are no sufficient data evaluating to what extent the addition of demineralized freeze-dried bone allograft (DFDBA) to PRP may enhance the effectiveness of PRP. The aim of this randomized, double-masked, controlled clinical trial was to compare the effectiveness of autologous PRP alone to PRP + DFDBA in periodontal endosseous defects.

METHODS

Twenty-four proximal endosseous defects in 24 patients with severe chronic periodontitis were randomly treated with PRP alone or in combination with DFDBA. The final evaluation at 6 months was based on clinical and radiographic parameters. Subtraction radiography was used. The primary outcome variable was clinical attachment level (CAL).

RESULTS

The two treatment groups were initially comparable (mean CAL: 8.67 +/- 2.19 mm for PRP + DFDBA and 8.25 +/- 1.96 mm for PRP). Both treatments achieved statistically significant and similar CAL gain (3.08 +/- 1.17 mm for PRP + DFDBA and 3.08 +/- 0.95 mm for PRP), probing depth, defect depth, and area surface reduction. The percentage of defect fill did not significantly differ between the two treatments. There was a non-significant trend to greater defect fill (45.42% versus 41.29%), defect depth (54.05% versus 49.52%), and area surface (58.43% versus 52.16%) reduction with the graft. In both groups, 66.66% of the defects gained > or =3 mm of CAL.

CONCLUSION

Within its limits, this study demonstrates that both PRP and PRP combined with DFDBA resulted in significant clinical and radiographic improvement in human periodontal endosseous defects at 6 months, and the addition of DFDBA to PRP did not significantly enhance the treatment outcome.

Effect of platelet-rich plasma on the healing of intrabony defects treated with an anorganic bovine bone mineral: a pilot study

BACKGROUND

Periodontal therapy using the combination of platelet-rich plasma (PRP) and different grafting materials has been suggested as a modality to enhance the outcome of regenerative surgery. In most clinical studies, a barrier membrane was used to cover the defects, and thus, the effects of PRP may have been masked by the effects of the barrier. The data from controlled clinical studies evaluating the effect of regenerative therapy using various grafting materials with or without PRP are still limited. The purpose of this study was to clinically compare the healing of intrabony defects treated with either a combination of an anorganic bovine bone mineral (ABBM) and PRP to those obtained with ABBM alone.

METHODS

Thirty patients with advanced chronic periodontal disease and displaying one intrabony defect were randomly treated with PRP + ABBM or ABBM alone. The following clinical parameters were evaluated at baseline and 1 year after treatment: plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), gingival recession (GR), and clinical attachment level (CAL). The primary outcome variable was CAL.

RESULTS

No statistical significant differences in any of the investigated parameters between the two groups were observed at baseline. Healing was uneventful in all patients. In the PRP + ABBM group, mean PD decreased from 8.6 +/- 1.8 mm to 3.4 +/- 1.4 mm (P <0.001) and mean CAL changed from 9.9 +/- 1.7 mm to 5.3 +/- 1.8 mm (P <0.001). In the ABBM group, mean PD decreased from 8.5 +/- 2.0 mm to 3.2 +/- 1.3 mm (P <0.001) and mean CAL changed from 9.6 +/- 1.9 mm to 4.9 +/- 1.5 mm (P <0.001). CAL gains >or=3 mm were measured in 80% (12 of 15 defects) of cases treated with PRP + ABBM and in 87% (13 of 15 defects) of cases treated with ABBM alone. No statistically significant differences in any of the investigated parameters were observed between the two groups at the 1-year reevaluation.

CONCLUSIONS

Within the limits of the present study, it can be concluded that 1) at 1 year after regenerative surgery with PRP + ABBM and ABBM alone, significant PD reductions and CAL gains were found, and 2) the use of PRP failed to improve the results obtained with ABBM alone.

The adjunctive use of platelet-rich plasma in the therapy of periodontal intraosseous defects: a systematic review

BACKGROUND AND OBJECTIVE

The evidence for the efficacy of the adjunctive use of platelet-rich plasma (PRP) in periodontal intraosseous defects has not been systematically evaluated. The objective of this review was to address the focused question, 'What is the efficacy, with respect to clinical, radiographical and patient-centred outcomes, of combinations of PRP with other therapeutic bioactive agents/procedures, compared with the efficacy of the same agents/procedures without the adjunctive use of PRP in the therapy of periodontal intraosseous defects in patients with chronic periodontitis and without systemic diseases that could potentially influence the outcome of periodontal therapy?' by performing a systematic review of randomized controlled clinical trials (RCTs) published in the dental literature in any language, up to and including September 2008.

MATERIAL AND METHODS

Data sources principally included electronic databases, manually searched journals and contact with experts. In the first phase of study selection, the titles and abstracts, and in the second phase, full papers were screened independently and in duplicate by two reviewers.

RESULTS

In the first phase, 6124 potentially relevant titles and abstracts were examined. In the second phase, the full text of 20 publications was thoroughly evaluated. Eventually, 10 RCTs were selected.

CONCLUSION

Diverse outcomes (positive and negative) have been reported for the efficacy of PRP combined with various therapeutic bioactive agents/procedures, reflecting the limited and heterogeneous data available and possibly suggesting that the specific selection of agents/procedures combined with PRP could be important. Additional research on the efficacy of each specific combination of PRP is necessary.

Effect of new bone substitute materials consisting of collagen and tricalcium phosphate

The purpose of this study was to investigate the effect of new bone substitute materials consisting of collagen and tricalcium phosphate (TCP). Prior to the experiment, mandibular dog teeth were extracted. After 3 months, specific cavities were prepared on the alveolar ridge. In one group, cavities were filled with collagen sponge (CS group), in the other, cavities were filled with TCP sponge (TCP group). Cavities with no fillings (Cont group) were created as controls. Mandibular bone was evaluated histopathologically at experimental time periods of 1, 2, 4, and 8 weeks. Due to the non critical inflammatory symptoms that each group showed throughout all the time periods investigated, a low irritation level was observed. Absorption of material was almost complete at after 4 weeks in the CS group, and at after 8 weeks in the TCP group. At the top of the cavity, the TCP group exceeded the Cont group in amount of neogenesis at after 8 weeks. The materials examined in this study showed good osteoconduction and biodegradable character. The TCP Group, in particular, showed highly acceptable results, demonstrating that the materials used were excellent candidates as bone substitute materials.

Localized delivery of growth factors for periodontal tissue regeneration: role, strategies, and perspectives

Difficulties associated with achieving predictable periodontal regeneration, means that novel techniques need to be developed in order to regenerate the extensive soft and hard tissue destruction that results from periodontitis. Localized delivery of growth factors to the periodontium is an emerging and versatile therapeutic approach, with the potential to become a powerful tool in future regenerative periodontal therapy. Optimized delivery regimes and well-defined release kinetics appear to be logical prerequisites for safe and efficacious clinical application of growth factors and to avoid unwanted side effects and toxicity. While adequate concentrations of growth factor(s) need to be appropriately localized, delivery vehicles are also expected to possess properties such as protein protection, precision in controlled release, biocompatibility and biodegradability, self-regulated therapeutic activity, potential for multiple delivery, and good cell/tissue penetration. Here, current knowledge, recent advances, and future possibilities of growth factor delivery strategies are outlined for periodontal regeneration. First, the role of those growth factors that have been implicated in the periodontal healing/regeneration process, general requirements for their delivery, and the different material types available are described. A detailed discussion follows of current strategies for the selection of devices for localized growth factor delivery, with particular emphasis placed upon their advantages and disadvantages and future prospects for ongoing studies in reconstructing the tooth supporting apparatus.

The use of platelet-rich plasma in bone reconstruction therapy

The use of platelet-rich plasma (PRP) in bone reconstruction therapy was introduced in the late 1990s. Since then, many scientists and clinicians have employed it in orthopaedic and oral surgeries. Unfortunately, studies that analyze the use of PRP are somewhat controversial as some conclude that the use of PRP may favor bone regeneration and others conclude that the use of PRP is irrelevant. By listing and analyzing the biological effect that each factor released by the activated platelets can have in bone regeneration, the present review answers the question of why PRP may be useful in bone reconstruction therapy. Subsequently, by examining the studies that have both successfully and unsuccessfully utilized PRP, it suggests how PRP might be used in order to achieve successful results in orthopaedic and dental bone reconstruction surgeries.

Effect of combined therapeutical methods on healing of intrabony defects in regenerative periodontal surgery

Several methods are available to enhance the healing and regeneration of periodontal tissues after surgical therapy of intrabony defects. The main indications for the use of combined regenerative procedures are the extent and morphology of the osseous lesions. The six studies of the present dissertation focused on the clinical effect of different barrier techniques, bone substitutes, enamel matrix derivatives and a growth factors containing adjuvant used in various combinations on the healing of severe periodontal intrabony impairments. Synthetic, xenogenetic and autologous materials were used in these randomized clinical studies. Mechanical barriers (polytetrafluoroethylene and collagen membranes) for GTR, biological barriers/enamel matrix proteins (EMD), synthetic (β-TCP) and xenogeneic (NBM) bone grafts and autologous platelet-rich plasma (PRP) were combined in the test and control groups of the trials. The main clinical variable was the clinical attachment level (CAL) and the subsidiary one was the probing pocket depth (PPD), estimated at baseline and after one year. The summation of the results after the statistical analysis takes cognizance of the followings: a) Each of the eleven regenerative methods evaluated (ten combined procedures) leads to significant CAL gain and PPD decrease. b) Using β-TCP or NBM with EMD or with PRP + GTR and GTR’s, the difference between the parameters of the test and control groups were not statistically significant. c) It was confirmed in four studies that the addition of PRP to graft materials has not increased significantly the positive outcomes independent of the type of barrier or graft. d) Adding platelet-rich plasma to natural bone mineral, no benefit was observed from the point of view of the clinical variables. e) The polypeptide proteins of the platelet-rich plasma do not enhance the clinical regenerative effect of enamel matrix proteins. In conclusion, the option of the periodontal surgeons between these methods depends mainly on the defect morphology, the patient’s approach to the different types of materials, the medical concept of the physician, the technical possibilities and the clinical experience of the periodontist.