|Year : 2017 | Volume
| Issue : 1 | Page : 9-16
Comparative evaluation of autologous platelet-rich fibrin and recombinant human bone morphogenetic protein-2 in the treatment of human periodontal intrabony defects: A randomized, controlled clinical and radiographic study
Laxman K Vandana, Shobha Prakash
Department of Periodontics, College of Dental Sciences, Davangere, Karnataka, India
|Date of Web Publication||20-Jan-2017|
Laxman K Vandana
Department of Periodontics, College of Dental Sciences, Room No. 4, Davangere, Karnataka
Source of Support: None, Conflict of Interest: None
Background: Autologous platelet rich fibrin (PRF) and Recombinant human bone morphogenetic protein 2 (rhBMP 2) technologies have been shown to significantly support alveolar bone. The present randomized, controlled clinical trial was conducted to compare the clinical and radiographic efficacy of autologous platelet rich fibrin (PRF) and recombinant human bone morphogenetic protein 2 (rhBMP 2) in the treatment of intrabony defects (IBDs) in patients with chronic periodontitis. Methods: A randomized controlled clinical trial conducted where in the IBDs were treated with either autologous PRF with open flap debridement (OFD) or recombinant rhBMP 2 with OFD or OFD alone. Clinical and radiologic parameters including probing pocket depth, clinical attachment level (CAL), IBD depth, defect fill, and percentage of original defect resolved were recorded at baseline and 6 months postoperatively. Results: The mean pocket depth reduction was greater in PRF (1.3 ± 0.78 mm) than rhBMP 2 group (1.3 ± 0.78 mm). No significant difference was seen in CAL gain in PRF and rhBMP 2 groups (3.3 ± 0.43 mm and 1.2 ± 0.74 mm, respectively). However, the percentage of original defect resolved was significantly greater in rhBMP 2 group (41.1% ± 19.2%) compared to PRF group (26.75% ± 6.03%). Conclusions: Within the limits of the present study, results suggest that in terms of hard tissue regeneration, rhBMP 2 has shown significantly better outcome in treatment of IBDs. However, PRF encourages superior soft tissue healing compared to rhBMP 2. Furthermore, added advantages of PRF being readily available and cost effective cannot be disregarded.
Keywords: Blood platelets, chronic periodontitis, clinical trial, dental, fibrin, growth differentiation factors, radiography, recombinant human bone morphogenetic protein-2, regeneration
|How to cite this article:|
Vandana LK, Prakash S. Comparative evaluation of autologous platelet-rich fibrin and recombinant human bone morphogenetic protein-2 in the treatment of human periodontal intrabony defects: A randomized, controlled clinical and radiographic study. Dent Med Res 2017;5:9-16
|How to cite this URL:|
Vandana LK, Prakash S. Comparative evaluation of autologous platelet-rich fibrin and recombinant human bone morphogenetic protein-2 in the treatment of human periodontal intrabony defects: A randomized, controlled clinical and radiographic study. Dent Med Res [serial online] 2017 [cited 2019 May 25];5:9-16. Available from: http://www.dmrjournal.org/text.asp?2017/5/1/9/198782
| Introduction|| |
Complete regeneration of the attachment apparatus (including new connective tissue attachment and new bone formation) in the treatment of intraosseous defects would be enhanced by the various biomaterials due to their osteoinductive capacities (exerted by the release of bone-inducing substances), osteoconductive properties (i.e., the possibility to create a scaffold to support bone formation), or osteogenic potential (if the graft contained viable bone-forming cells). Researchers for many years have attempted to use biologically active molecules to achieve periodontal regeneration, which include (1) extracellular matrix proteins and cell-attachment factors; (2) mediators of cell metabolism and activity; and (3) growth/differentiation factors. In animal experiments, a number of growth factors, alone or in combination, have been tested for periodontal regeneration which include the following: (1) Insulin-like growth factors, (2) fibroblast growth factors, (3) epidermal growth factor, (4) platelet-derived growth factor (PDGF), (5) vascular endothelial growth factor, (6) parathyroid hormone, (7) transforming growth factor-β (TGF-β), and (8) bone morphogenetic proteins (BMPs).
Preparing autologous platelet-rich fibrin (PRF), introduced by Choukroun, is an opportune technique to obtain a high concentration of PDGFs. PRF, the second generation platelet concentrate, consists of an assembly of glycanic chains, cytokines, and structural glycoproteins enmeshed within a slowly polymerized fibrin network. PRF functions by promoting the expression of phosphorylated extracellular signal-regulated protein kinase and stimulating the production of osteoprotegerin (naturally occurring inhibitor of osteoclast differentiation) in turn causing osteoblastic proliferation. Beneficial effects of PRF have been studied in various procedures, including treatment of periodontal intrabony defects (IBDs),, and also as a scaffold for breeding human periosteal cells in vitro, which may be suitable for bone tissue engineering applications.
A great amount of knowledge has now been gained regarding the molecular signals that determine the emergence of complex tissue morphologies during regeneration of the periodontal tissues., BMP plays a necessary role in normal chondrocyte and osteoblast differentiation and postnatal bone formation which is essential for periodontal regeneration.,, BMPs form a unique family within the TGF-β superfamily of proteins that play essential role in regulation of bone formation and repair. Previously BMPs were referred to as growth factors, but they are now regarded as differentiation factors, because of their involvement in morphogenesis and organogenesis. Recombinant technologies have been used to produce BMPs for therapeutic evaluation, and in 2002, the US Food and Drug Administration approved BMP-2 and BMP-7 for use in bone regeneration. BMPs play an important role in the process of bone modeling and remodeling through chemotactic, mitogenic, or differentiating mechanism.
Hence, it appears that both autologous PRF and BMPs are potential regenerative materials with growth and differentiation factors capable of periodontal regeneration. Medline search using key words “intra-osseous defect,” “comparison,” “clinical,” “radiographic,” “PRF” and “BMP” did not reveal any study. Thus, the purpose of the present study was to compare the clinical and radiographic efficacy of autologous PRF and recombinant human bone morphogenetic protein-2 (rhBMP-2) with open-flap debridement (OFD) in the treatment of 2–3-wall IBDs. To the best of our knowledge, no study has reported the clinical and radiographic comparison of the use of autologous PRF and rhBMP-2 for the treatment of periodontal IBDs in periodontal literature.
| Materials and Methods|| |
Patient recruitment and presurgical preparation
In this 6-month follow-up, randomized, double-masked study, 32 participants (18 males and 14 females) between the age group of 25–45 years who were undergoing periodontal therapy at the Department of Periodontics, College of Dental Sciences, Davangere, India, were selected to be included in the study. The study was conducted from January 2010 to February 2011. The research protocol was initially submitted to the Institutional Ethics Committee and Review Board of the College of Dental Sciences, Davangere. After ethical approval, all participants were verbally informed, and written informed consent was obtained for participation in the study.
Patients diagnosed as having chronic periodontitis with at least two 2–3 wall IBD ≥3 mm deep (distance between alveolar crest (AC) and base of the defect (BD) on an intraoral periapical radiograph) along with an interproximal probing depth (PD) ≥5 mm after Phase-I therapy (scaling and root planing) in asymptomatic teeth were included in the study. The followings are the exclusion criteria: (1) Aggressive periodontitis, (2) known systemic illness, (3) medications known to affect periodontal therapy, (4) smoking/tobacco use, (5) pregnancy or lactation, and (4) insufficient platelet count (ɘ200,000/mm 3). Those having unacceptable oral hygiene (plaque index [PI] >1.5) after reevaluation of Phase-I therapy, and those who had undergone periodontal therapy 3 months before the study were excluded from the study. In addition, teeth with furcation defects, gingival recession, nonvitality, and/or mobility of at least Grade II were also excluded from the study.
All the selected patients, following an initial examination and treatment plan discussion, were given detailed instructions in self-performed plaque control measures and were subjected to Phase-I periodontal therapy. Selective grinding was done in cases with trauma from occlusion. 2–3 weeks after Phase-I therapy, the oral hygiene status and the tissue response were evaluated using PI  and gingival index (GI). If the oral hygiene was acceptable, i.e., PI ≤1, patients were subjected to surgical procedure.
Groups and randomization
This was a split-mouth study design with two separate controls for the two test groups. Following enrollment, sites were randomly assigned to one of four different treatments: Group 1 (control for PRF): OFD alone, i.e., conventional flap surgery; Group 2 (test): OFD plus autologous PRF; Group 3 (control for rhBMP-2): OFD alone, i.e., conventional flap surgery; and Group 4 (test): OFD plus rhBMP-2 (Altis OBM) [Figure 1]. Random allocation was done by computer-generated random numbers.
Altis OBM (Altis Biologics Pvt., Ltd., South Africa), a composite of three-porcine bone matrix-derived protein fractions, was provided as a lyophilized powder in a sterile syringe. It comprised porcine bone collagen, bone gelatin, and BMP (3–12 mg). Altis OBM (Altis Biologics Pvt., Ltd., South Africa), an implantable biomaterial (biological medicine) intended as a bone graft substitute with bioresorbable, osteoconductive nature and also provides scaffolding effect.
PRF was prepared by drawing intravenous blood from the antecubital fossa of the patient. Whole blood (approximately 4–5 ml) was drawn in 10 ml sterile dry glass test tubes without anticoagulant and immediately centrifuged at 3000 rpm for 10 min. Due to the differential densities, the centrifugation process resulted the separation of blood into three basic fractions: A base of red blood cells at the bottom, acellular plasma on the surface, and a PRF clot between the two. The PRF clot/gel located in the middle of the tube soaked in acellular plasma was removed with a Tweezer and used as graft material at the experimental site.,
Clinical and radiographic measurements
On the day of the surgical procedure, baseline clinical measurements were recorded by calibrated examiner masked to the treatment; measurements were repeated 6 months postsurgery using the same type of probe (UNC-15 probe) and previously used acrylic stents. The outcome variables included PI, GI, and probing pocket depth (PPD) from the gingival margin and clinical attachment level (CAL) from the apical level of customized acrylic stents with grooves to ensure a reproducible placement of the periodontal probe.
All IBDs were evaluated at baseline and 6 months postoperatively. Radiographs were taken at the initial examination and 6 months postsurgery by the same investigator who performed the clinical measurements. Standardized radiographs were taken using the paralleling technique and holders. The following linear distances were measured in millimeters: The distance from the AC to the BD, the distance from the cementoenamel junction (CEJ) to the BD, and distance from CEJ to AC. The most coronal area where PDL maintained an even width was identified to measure the most apical extension of the IBD.
The same examiner masked to the procedure category performed all measurements. The differences between the 6-month and baseline values for CEJ-BD indicated the amount of hard tissue fill (HTF) within the osseous defect. The differences between CEJ-BD and CEJ-AC recorded at baseline and at 6 months were as the depth of the IBD and amount of crestal bone resorption, respectively. Defect resolution was defined as the percentage change in AC-BD.
The digitized radiographic measurements using CorelDRAW 10 was used to record the changes in the bony defects. The position of the CEJ was identified as described by Schei et al. The most coronal area where the periodontal ligament maintained an even width was identified as the most apical extent of the IBD.
Baseline surgical procedures and postoperative care
The standard surgical procedure included crevicular and interdental incisions, full thickness mucoperiosteal flap reflection, a thorough surgical debridement followed by copious irrigation. Presuturing was done at the test site to place the graft material into the osseous defect following which primary closure of the flaps was achieved using sutures. All surgical sites were dressed with Coe-Pak periodontal dressing for 7 days. Prescriptions for anti-inflammatory medication (paracetamol - 625 mg BID for 3 days), antibiotic (amoxicillin - 500 mg TID for 5 days), and a mouthrinse (chlorhexidine 0.12%, 16 oz) were provided. At 1 week postoperatively, dressing and sutures were removed, and oral hygiene instructions were reinforced. No further dressing was placed. At 1, 2, 3, and 4 weeks and 3 months, the sites were reexamined.
The data were analyzed using statistical software (SPSS version 11.5, USA). Paired t-test was applied to assess the statistical significance between time points within each group for clinical and radiographic parameters. Unpaired t-test was applied to assess the statistical significance between time points among the groups for clinical and radiographic parameters. The results were averaged (mean standard deviation) for each clinical and radiographic parameter at baseline and 6 months. The mean intra-examiner standard deviation of differences in repeated PD measurements and CAL measurements was obtained using single passes of measurements with a periodontal probe (UNC-15 periodontal probe, Hu-Friedy) (correlation coefficients between duplicate measurements; r = 0.95). For all the tests, P ≤ 0.05 was considered statistically significant.
| Results|| |
All 32 patients enrolled completed the study with no dropouts. The study participants experienced no adverse reactions related to the treatment. Postsurgical healing was uneventful in all the sites involved in the study. Results of the study are expressed in [Table 1],[Table 2],[Table 3],[Table 4].
|Table 1: Clinical parameters gingival index, probing pocket depth, clinical attachment level, and radiographic changes in platelet-rich fibrin and control group at 6 months|
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|Table 2: Clinical (gingival index, probing pocket depth, and clinical attachment level) and radiographic parameters in recombinant human bone morphogenetic protein-2 and control group at 6 months|
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|Table 3: Clinical parameters gingival index, probing pocket depth, and clinical attachment level in platelet-rich fibrin and recombinant human bone morphogenetic protein-2 group at baseline and 6 months|
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|Table 4: Radiographic changes in platelet-rich fibrin group and recombinant human bone morphogenetic protein-2 Group 6 months postsurgery|
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At baseline, there was no significant difference in the rhBMP-2-treated and PRF-treated groups for GI, PPD, and CAL. A statistically significant reduction in GI (P < 0.02) was observed within the groups at 6 months postoperatively. On intragroup comparison, the pocket depth (PPD) reduction was statistically greater in PRF-treated sites compared to control sites (P = 0.002). The pocket depth reduced a mean of 4.5 ± 0.35 mm in PRF-treated sites and 3.5 ± 0.24 mm control sites at 6 months [Table 1]. On the contrary, pocket depth (PPD) reduction was statistically not significant between rhBMP-2-treated and control sites at 6 months (P = 0.95) as the pocket depth reduced a mean of 1.3 ± 0.71 mm in rhBMP-2-treated sites and 1.47 ± 1.13 mm in control sites at 6 months [Table 2]. On intergroup comparison, the mean Pocket depth reduction was significant greater (P = 0.025) in PRF-treated sites (4.5 ± 0.35 mm) as compared to rhBMP-2 (1.3 ± 0.78 mm) at 6 months [Table 3].
The improvement in CAL was significantly greater in the PRF-treated sites when compared to control sites (OFD alone) at 6 months. CAL improved a mean of 3.3 ± 0.43 mm in PRF-treated sites and 1.5 ± 0.1 mm in control sites (P = 0.004) [Table 1]. On the contrary, the CAL gain was statistically not significant at 6 months between rhBMP-2-treated sites and control sites; the CAL improved a mean of 1.2 ± 0.7 mm and 0.92 ± 0.76 mm in rhBMP-2-treated sites and control sites, respectively (P = 0.51) [Table 2]. On intergroup comparison, CAL improvement was statistically not significant (P = 0.12) in rhBMP-2-treated sites (1.2 ± 0.74 mm) compared to PRF-treated sites (3.3 ± 0.43 mm) [Table 3].
At baseline, the initial defect depth was 4.11 ± 1.16 mm in the PRF-treated group [Figure 2] and 2.97 ± 1.2 mm in the rhBMP-2-treated group [Figure 3] which was statistically not significant (P = 0.92). On intragroup comparison, at 6 months, the HTF in the PRF-treated sites was significantly greater (P = 0.005) than the control sites (OFD) [Table 1]. On the contrary, the HTF was statistically not significant (P = 3.92) in the rhBMP-2-treated sites compared to their controls (OFD) [Table 2]. On intergroup comparison, the HTF was 1.6 ± 0.30 mm in PRF-treated group [Figure 4] and 1.04 ± 0.56 mm in the rhBMP-2-treated group [Figure 5] at 6 months postsurgery which was statistically not significant (P = 0.07). The percentage of original defect resolved was significantly greater in rhBMP-2-treated group (41.1%) compared to PRF-treated group (26.75%) at 6 months (P = 0.001) [Table 4].
|Figure 2: Baseline radiograph test Group 1 (platelet-rich fibrin + open-flap debridement).|
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|Figure 3: Baseline radiograph test Group 2 (recombinant human bone morphogenetic protein-2 + open-flap debridement).|
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|Figure 4: Six months postoperative radiograph test Group 1 (platelet-rich fibrin + open-flap debridement).|
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|Figure 5: Six months postoperative radiograph test Group 2.(recombinant human bone morphogenetic protein-2).|
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| Discussion|| |
The current perspective states that regenerative periodontal therapy can only restore a fraction of original tissue volume  and have a limited potential in attaining complete periodontal restoration. To increase the amount and predictability of regeneration, many different biological mediators including differentiating polypeptides, growth factors, and extracellular matrix proteins have been evaluated for their ability to stimulate reattachment and bone growth. Choukroun's PRF, one such material, is a matrix of autologous fibrin, in which intrinsically a large quantity of platelet and leukocyte cytokines are embedded during centrifugation leading to their progressive release over time (7–11 days), as the network of fibrin disintegrates. Research in molecular biology leads to identification of initiators of bone differentiation called BMPs that regulate cartilage and bone differentiation first identified by Urist, 1965. Urist's identification of BMP, one such material with powerful abilities to promote osteoblastic mitogenesis and differentiation, is rhBMP-2.
The present study intended to explore and compare the clinical and radiographic effectiveness of autologous PRF and rhBMP-2 in the treatment of IBDs in patients with chronic periodontitis and presents a significant improvement in clinical as well as radiographic parameters in both PRF- and rhBMP-treated groups. The results of the study are interpreted as follows: There was no baseline difference in the clinical and radiographic measurements. Application of PRF compared to OFD alone in IBDs has shown significant reduction in of GI scores, PPD, and a significantly greater CAL gain, as well as radiographic HTF and defect resolution. A number of clinical and radiographic studies have reported congruent findings while evaluating the effects of PRF in the treatment of intraosseous and Grade II furcation defects. Greater pocket depth reduction, CAL gain and IBD fill were observed at sites treated with PRF compared to OFD alone.,,,
Plaque infection and smoking are the important factors that have been shown to significantly influence the outcomes of regenerative periodontal surgery., Because the current study excludes smokers and includes only those participants who are able to maintain acceptable oral hygiene, it may be assumed that careful patient selection was also responsible for the positive outcomes obtained in both groups.
In the current study, the PPD reduction and CAL gain showed no significant difference at 6 months between rhBMP-2 and OFD groups. The HTF was significant in the rhBMP-2 group than in OFD group at 6 months (P < 0.002), and the percentage of original defect resolved was highly significant (P < 0.001) The BMPs are considerably involved in the healing of surgical wounds, especially in periodontal regeneration, since they initiate formation of new bone tissue by stimulating the differentiation of undifferentiated mesenchymal cells in osteoblasts. The formation of new bone in surgically created defects treated with BMPs has been reported in a microscopic study. Microscopic studies have shown the formation of new cementum, periodontal ligament, and bone neoformation by application of rhBMP-2,,, and other BMPs.,, Many microscopic studies have supported the premise that the BMPs provide regeneration of the tooth-supporting apparatus, including the cementum, periodontal ligament, and alveolar bone.,,,,,,,
Guimaraes et al. reported the treatment of human intrabony defects using pooled BMP + guided tissue regeneration (GTR) in 15 patients with 10 pairs of intrabony defects and demonstrated no significant difference between test (BMP + GTR) and control groups at 6 months in PPD reduction and CAL improvement. The drawback of this study was done over 6-month period without the radiographic assessment. In the current study, the amount of rhBMP-2 used was 3–12 mg which was adequate to bring about clinically significant changes in test sites. In contrast to the above study, a randomized, double-blind controlled trail in humans explored the effect of rhBMP-2 clinically and radiographically, following periodontal flap surgery in vertical defects and reported significant improvement in clinical and radiographic parameters at 9 months compared to OFD alone (unpublished data).
The digitized radiographic measurements using CorelDRAW 10 provided useful measurable tool to record the noticeable changes in the bony defects from CEJ and AC. The HTF considered the static CEJ as landmark to study the defect depth measurements wherein the AC changes are not included. To circumvent this problem, percentage of original defect resolved was calculated using AC changes to evaluate defect depth changes pre- and post-surgically. By this radiographic measurement of the baseline defect dimension, improvement will be ascertained which should be considered for radiographic measurements in clinical trials.
In the present study, intergroup comparison for clinical and radiographic parameters between the PRF and rhBMP-2-treated sites revealed varied results. The Pocket Depth reduction was significantly greater in PRF group compared to rhBMP-2 group. The improvement in CAL was similar in both PRF and rhBMP-2 group. However, percentage of original defect resolved was significantly greater in rhBMP-2-treated group compared to autologous PRF. Till date, there are no clinical or radiographic studies comparing PRF and rhBMP in the treatment of IBDs existing in the literature.
Improvement in the soft tissue parameters (soft tissue healing) following regenerative therapy not by themselves provides direct proof of the formation of new bone, cement, or PDL. New bone formation (Hard tissue healing) measured indirectly by radiographic techniques is the primary alternative to histology to assess regeneration as it directly measures the formation of one of the three components required for successful regeneration. While the healing of gingival epithelia and their underlying connective tissues concludes in a number of weeks, the regeneration of periodontal ligament, root cementum, and alveolar bone generally occur within a number of weeks or months. The effect of rhBMP on CAL improvement and significantly higher defect fill was observed at 9 months when compared to OFD sites than at 6 months (unpublished data). This is suggestive of long-term (>6 months) evaluation of any graft material. Therefore, the effect of rhBMP on hard tissue healing can be truly assessed after a longer evaluation period. Hence, further research on the hard tissue healing potential of rhBMP is required with assessment at 9 and 12 months.
| Conclusion|| |
The results obtained in the present study suggest that rhBMP performs as a potentially superior graft material as compared to PRF in terms of hard tissue regeneration and CAL improvement when treating periodontal IBDs. However, the advantages of PRF such as improved soft tissue healing, being readily obtainable, and economical cannot be neglected while comparing the two periodontal regenerative materials in question. However, further long-term randomized clinical trials with split-mouth design, larger sample size and long-term evaluation period will be needed to confirm the findings of the present study.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Trombelli L. Which reconstructive procedures are effective for treating the periodontal intraosseous defect? Periodontol 2000 2005;37:88-105.
Bosshardt DD, Sculean A. Does periodontal tissue regeneration really work? Periodontol 2000 2009;51:208-19.
Chang IC, Tsai CH, Chang YC. Platelet-rich fibrin modulates the expression of extracellular signal-regulated protein kinase and osteoprotegerin in human osteoblasts. J Biomed Mater Res A 2010;95:327-32.
Sharma A, Pradeep AR. Treatment of 3-wall intrabony defects in chronic periodontitis subjects with autologous platelet rich fibrin – A randomized controlled clinical trial. J Periodontol 2011;82:1705-12.
Thorat M, Pradeep AR, Pallavi B. Clinical effect of autologous platelet-rich fibrin in the treatment of intra-bony defects: A controlled clinical trial. J Clin Periodontol 2011;38:925-32.
Gassling V, Douglas T, Warnke PH, Açil Y, Wiltfang J, Becker ST. Platelet-rich fibrin membranes as scaffolds for periosteal tissue engineering. Clin Oral Implants Res 2010;21:543-9.
Bartold PM, McCulloch CA, Narayanan AS, Pitaru S. Tissue engineering: A new paradigm for periodontal regeneration based on molecular and cell biology. Periodontol 2000 2000;24:253-69.
Ripamonti U, Reddi AH. Tissue engineering, morphogenesis, and regeneration of the periodontal tissues by bone morphogenetic proteins. Crit Rev Oral Biol Med 1997;8:154-63.
Urist MR. Bone: Formation by autoinduction. Science 1965;150:893-9.
Urist MR, Strates BS. Bone morphogenetic protein. J Dent Res 1971;50:1392-406.
Ripamonti U, Reddi AH. Periodontal regeneration: Potential role of bone morphogenetic proteins. J Periodontal Res 1994;29:225-35.
Lee J, Stavropoulos A, Susin C, Wikesjö UM. Periodontal regeneration: Focus on growth and differentiation factors. Dent Clin North Am 2010;54:93-111.
Rao SM, Ugale GM, Warad SB. Bone morphogenetic proteins: Periodontal regeneration. N Am J Med Sci 2013;5:161-8.
Huang YH, Polimeni G, Qahash M, Wikesjö UM. Bone morphogenetic proteins and osseointegration: Current knowledge-future possibilities. Periodontol 2000 2008;47:206-23.
Sykaras N, Opperman LA. Bone morphogenetic proteins (BMPs): How do they function and what can they offer the clinician? J Oral Sci 2003;45:57-73.
Silness J, Loe H. Periodontal disease in pregnancy. II. Correlation between oral hygiene and periodontal condtion. Acta Odontol Scand 1964;22:121-35.
Loe H, Silness J. Periodontal disease in pregnancy. I. Prevalence and severity. Acta Odontol Scand 1963;21:533-51.
Dohan DM, Choukroun J, Diss A, Dohan SL, Dohan AJ, Mouhyi J, et al
. Platelet-rich fibrin (PRF): A second-generation platelet concentrate. Part I: Technological concepts and evolution. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;101:e37-44.
Greenwell H; Committee on Research, Science and Therapy. American Academy of Periodontology. Position paper: Guidelines for periodontal therapy. J Periodontol 2001;72:1624-8.
Vandana KL, Shah K, Prakash S. Clinical and radiographic evaluation of Emdogain as a regenerative material in the treatment of interproximal vertical defects in chronic and aggressive periodontitis patients. Int J Periodontics Restorative Dent 2004;24:185-91.
Schei O, Waerhaug J, Lovdal I, Arno A. Alveolar bone loss as related to oral hygiene and age. J Periodontol 1959;30:7-16.
Sander L, Karring T. Healing of periodontal lesions in monkeys following the guided tissue regeneration procedure. A histological study. J Clin Periodontol 1995;22:332-7.
Cochran DL, Wozney JM. Biological mediators for periodontal regeneration. Periodontol 2000 1999;19:40-58.
Bansal C, Bharti V. Evaluation of efficacy of autologous platelet-rich fibrin with demineralized-freeze dried bone allograft in the treatment of periodontal intrabony defects. J Indian Soc Periodontol 2013;17:361-6.
Pradeep AR, Pai S, Garg G, Devi P, Shetty SK. A randomized clinical trial of autologous platelet-rich plasma in the treatment of mandibular degree II furcation defects. J Clin Periodontol 2009;36:581-8.
Sharma A, Pradeep AR. Autologous platelet-rich fibrin in the treatment of mandibular degree II furcation defects: A randomized clinical trial. J Periodontol 2011;82:1396-403.
Trombelli L, Kim CK, Zimmerman GJ, Wikesjö UM. Retrospective analysis of factors related to clinical outcome of guided tissue regeneration procedures in intrabony defects. J Clin Periodontol 1997;24:366-71.
Tonetti MS, Prato GP, Cortellini P. Factors affecting the healing response of intrabony defects following guided tissue regeneration and access flap surgery. J Clin Periodontol 1996;23:548-56.
Zaman KU, Sugaya T, Kato H. Effect of recombinat human plated-derived growth factor-BB and bone morphogenetic protein-2 application to demineralized dentin on early periodontal ligament cell response. J Periodontol Res 1999;34:244-50.
Giannobile WV, Ryan S, Shih MS, Su DL, Kaplan PL, Chan TC. Recombinant human osteogenic protein-1 (OP-1) stimulates periodontal wound healing in class III furcation defects. J Periodontol 1998;69:129-37.
King GN, King N, Cruchley AT, Wozney JM, Hughes FJ. Recombinant human bone morphogenetic protein-2 promotes wound healing in rat periodontal fenestration defects. J Dent Res 1997;76:1460-70.
Kinoshita A, Oda S, Takahashi K, Yokota S, Ishikawa I. Periodontal regeneration by application of recombinant human bone morphogenetic protein-2 to horizontal circumferential defects created by experimental periodontitis in beagle dogs. J Periodontol 1997;68:103-9.
Sasaki M, Kato H, Kuboki Y. A study of periodontal regenerative therapy using bone morphogenetic protein (BMP)-treatment of monkey's furcation involvement using collagen membrane as a spacer. J Jpn Soc Periodontol 1996;38:428-46.
Sigurdsson TJ, Nygaard L, Tatakis DN, Fu E, Turek TJ, Jin L, et al.
Periodontal repair in dogs: Evaluation of rhBMP-2 carriers. Int J Periodontics Restorative Dent 1996;16:524-37.
Ripamonti U, Heliotis M, van den Heever B, Reddi AH. Bone morphogenetic proteins induce periodontal regeneration in the baboon (Papio ursinus
) J Periodontal Res 1994;29:439-45.
Ripamonti U, Heliotis M, Rueger DC, Sampath TK. Induction of cementogenesis by recombinant human osteogenic protein-1 (hop-1/bmp-7) in the baboon (Papio ursinus
). Arch Oral Biol 1996;41:121-6.
Bowers G, Felton F, Middleton C, Glynn D, Sharp S, Mellonig J, et al.
Histologic comparison of regeneration in human intrabony defects when osteogenin is combined with demineralized freeze-dried bone allograft and with purified bovine collagen. J Periodontol 1991;62:690-702.
King GN, King N, Hughes FJ. Effect of two delivery systems for recombinant human bone morphogenetic protein-2 on periodontal regeneration in vivo
. J Periodontal Res 1998;33:226-36.
Guimarães Mdo C, Passanezi E, Sant'ana AC, Greghi SL. Pool of bovine morphogenetic proteins and guided tissue regeneration in the treatment of intrabony periodontal defects: I-Clinical measurements. J Appl Oral Sci 2004;12:70-7.
Machtei EE. Outcome variables for the study of periodontal regeneration. Ann Periodontol 1997;2:229-39.
Ramseier CA, Rasperini G, Batia S, Giannobile WV. Advanced reconstructive technologies for periodontal tissue repair. Periodontol 2000 2012;59:185-202.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2], [Table 3], [Table 4]