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Journal of Hard Tissue Biology 28[2] (2019) 185-1902019 The Hard Tissue Biology Network AssociationPrinted in Japan, All rights reserved.CODEN-JHTBFF, ISSN 1341-7649

OriginalA Randomized Controlled Clinical Study of Autologous Platelet Rich Fibrin (PRF) in Combination

with HA and Beta-TCP or HA and Beta-TCP Alone for Treatment of Furcation Defects

Ashish Dambhare1), Manohar Laxmanrao Bhongade1), Prasad V Dhadse1), Bhumika Sehdev2), Kiran Kumar Ganji3), Kaustubh Thakare1), Hiroshi Murakami4), Yoshihiko Sugita5), Hatsuhiko Maeda5) and Mohammad Khursheed Alam6)

1) Department of Periodontics, Sharad Pawar Dental College, DMIMS, Nagpur, India2) Department of Periodontics, Mekelle University, Mekelle, Ethiopia3) Periodontics Division, College of Dentistry, Jouf University, Sakaka, Saudi Arabia4) Division of Implant Dentistry, Department of Gerodentistry, School of Dentistry, Aichi Gakuin University, Nagoya, Japan5) Department of Oral Pathology, School of Dentistry, Aichi Gakuin University, Nagoya, Japan6) Orthodontics Division, College of Dentistry, Jouf University, Sakaka, Saudi Arabia(Accepted for publication, March 10, 2019)

Correspondence to: Dr. Kiran Kumar Ganji, Periodontics section, Department of Preventive Dentistry, College of Dentistry, Jouf University, Sakaka 72721, Kingdom of Saudi Arabia; Tel: + 966 540640338; Email: kiranperio@gmail.com

Abstract: An increased knowledge of specific cellular response and function has led to the development of numerous treat-ment modalities based on the utilization of growth factors. The present controlled clinical study was undertaken to evaluate the effectiveness of autologous platelet rich fibrin (PRF) in combination with HA and beta-TCP in treatment of human class II furcation defects and to compare it with HA and beta-TCP alone. A total of 24 interproximal defects in 24 chronic perio-dontitis patients were included in the study. The test group was treated by an open flap debridement in combination with au-tologous platelet rich fibrin (PRF) in combination with hydroxyapatite beta tricalcium phosphate, while the control group was treated by an open flap debridement (OFD) along with hydroxyapatite and beta tricalcium phosphate. At 12 months, both the test and control groups showed significant mean PPD reduction and CAL gain. There was statistically significant (p<0.05) greater probing depth reduction of 1.50 mm for the test group compared to the control. The mean Clinical Attach-ment Level (CAL) gains of 3.0 ± 0.95 mm was observed in the test group, while the control group displayed mean CAL gains of 2.00 ± 0.85 mm. The observed differences between baseline CAL and 12 months CAL were found to be statistical-ly significant in both the groups (p<0.05). The mean CAL gain observed in the test group was significantly greater than the control group. Horizontal probing depth were significantly reduced in test group (3.33 ± 0.83 mm) compared to control group (1.75 ± 1.21 mm). Frequency analysis of furcation changes revealed complete furcation closure in 50% sites in test groups than control group which showed only 16.66% sites of complete resolution of furcation defects. The treatment with PRF in combination with HA and β-TCP group resulted in a significantly higher CAL gain, PPD and HPD reduction in comparison with hydroxyapatite and beta tricalcium phosphate.

Key words: Platelet rich fibrin, Furcation, Beta tricalcium phosphate, Hydroxyapatite

IntroductionThe ideal goal of furcation therapy is to retain the tooth by achieving

complete closure of the furcation defect thus improving the prognosis of involved tooth1,2). Class II Furcation defects with their unique anatomy, pose a special therapeutic challenge. Several techniques have been pro-posed to treat and improve the clinical condition of mandibular class II furcation involved molars with varying results2,3).

It was suggested that the combination treatment including both bone replacement graft + GTR would provide the most beneficial regenera-tive therapy for class II furcation defects4). The advantage of using a bone graft with membrane was to establish initial blood clot stabiliza-tion and decrease the potential of having dead space under the mem-brane5). However, the results obtained in controlled clinical studies demonstrated that the use of bone graft together with barrier membrane

was of limited significance1,6). Therefore, the use of replacement graft to improve the result of guided tissue regeneration therapy was not clearly justified.

The emergence of different biomaterials such as the use of bone morphogenic protein (BMP), Enamel matrix protein derivatives (EMD) and growth factors in the field of periodontics have provided researchers with varied treatment options for the management of class II furcation defects. Studies have demonstrated that application of biomaterials in combination with bone graft substitutes were found to be an effective treatment modality in the management of infrabony defects and grade II furcation defects, exhibiting improvement in clinical parameters and bone fill7). However, there is no single regenerative material to be con-sidered as the gold standard in the treatment of Grade II furcation de-fects.

Carroll et al.8) in his in vitro study demonstrated that the viable plate-lets in PRF releases growth factors like Platelet Derived Growth Factor (PDGF), Vascular Endothelial Growth Factor (VEGF), Transforming Growth Factor (TGF), Insulin like Growth Factor (IGF), Epithelial

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Growth Factor (EGF) and basic Fibroblast Growth Factor (bFGF) in about the same concentration for a duration of 7 days. Beneficial effects of PRF have been studied in various surgical procedures like sinus floor augmentation during implant placement9) in multiple gingival recessions with coronally displaced flap10) and in facial plastic surgical proce-dures11). Beta tricalcium phosphate (β-TCP) is a purified, multicrystal-line, porous form of calcium phosphate with Ca:PO4 ratio similar to that of natural bone material. It provides matrix or scaffolding for periodon-tal regeneration and also facilitates the stabilization of the blood clot12).

Recently Lekovic et al.13) demonstrated that, PRF in combination with bovine porous bone mineral has the ability to increase the regener-ative effect in infrabony defects. The intended role of PRF in the in-frabony defects was to deliver the growth factors in the early phase of

healing. However, to our knowledge, there are no studies reported on the use of autologous PRF, in combination with bone graft, in the treat-ment of furcation defects. The aim of the present study was to evaluate the effectiveness of autologous PRF in combination with β-TCP in the treatment of human mandibular class II furcation defects.

Materials and MethodsA total of 24 class II furcation defects in 24 moderate to advanced

chronic periodontitis patients in the age range of 34 to 49 years (40 ± 4.29) were selected for the study from the Outpatient Department of Periodontics, S P Dental College, Sawangi (Meghe), Wardha, India. Ethical approval was obtained from Institutional ethical committee vide reference number IEC/2589/2017. The patients were required to fulfill

Figure 1. Surgical procedure for test and control group(A) Horizontal probing depth using Naber’s Probe. (B) After reflection of full thickness flap. (C) Horizontal defect depth measurement. (D) Ver-tical defect depth measurement. (E) β-TCP filled into furcation defect after pre-suturing the flap. (F) PRF placed in furcation defect. (G) Flap su-tured. (H) After placement of periodontal pack. (I) Case I Pre-operative photograph. (J) Case I Post-operative photograph. (K) Case II Pre-oper-ative photograph. (L) Case II Post-operative photograph

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the following inclusion criteria: i) systemically healthy subjects, ii) Presence of Class II furcation defect involving either buccal or lingual surfaces of the mandibular molars as determined by clinical and radio-graphic evaluation, iii) Presence of <3 mm horizontal furcation probing depth, iv) Presence of <3 mm of vertical furcation probing depth, v) The experimental tooth having proximal bone height coronal to the in-ter-radicular bone level. Aggressive periodontitis patients and patients who are non-compliant to periodontal maintenance program (plaque in-dex score >1), smokers, pregnant females or lactating mothers were ex-cluded from the study.

After proper examination and diagnosis, initial therapy consisting of oral hygiene instructions, supra and subgingival scaling and root planing under local anesthesia were performed. Occlusal adjustment, if neces-sary, was performed to control occlusal trauma. A custom made occlusal acrylic stent was used to standardize the probing measurements.

A total of 24 class–II furcation defects in 24 patients on mandibular molars involving either buccal or lingual surfaces were found suitable after initial therapy. Prior to surgery, selected defects were randomly as-signed to test and control groups by a coin flip each consisting of 12 de-fects, according to randomized parallel design. Test group was treated by an open flap debridement (OFD) along with PRF + HA and β-TCP (Ossifi, Equinox Medical Technologies B.V, Amersfoort, Netherlands) and control group was treated by an OFD along with HA and β-TCP only.

The clinical measurements recorded were probing pocket depth (PPD), relative clinical attachment level (R-CAL), relative gingival marginal level (R-GML) and Horizontal probing depth (HPD) of furca-tion. All the clinical measurements were recorded on the day of surgery and at 12 months’ post-surgery. A blinded examiner made the pre-treat-ment and post treatment clinical measurements. Patient’s oral hygiene status was evaluated by plaque index. Gingival inflammation was as-sessed by papillary bleeding index.

Surgical procedure (Fig.1A-L)The surgical procedure included a pre-surgical rinse, administration

of local anesthesia (2% Xylocaine containing 1:80,000 concentration of epinephrine) and raising a full thickness mucoperiosteal flap on either facial or lingual side depending upon involvement of furcation. A thor-ough surgical debridement of furcation defect was performed. The root surfaces were planed until a smooth hard consistency was obtained. At this stage, horizontal defect depth (HDD): of the furcation defect was measured horizontally at its deepest location, using UNC 15 probe and another reference probe placed across the most prominent root surface to bridge the first probe. Vertical defect depth (VDD): of the furcation defect was measured vertically at its deepest location using the fornix of the furcation as the fixed reference point. The test site defect was treated with OFD with insertion of PRF + HA and β-TCP (Ossifi, Equinox Medical Technologies B.V, Amersfoort, Netherlands).

PRF preparation On the day of surgery, 10 ml of blood was drawn from each patient

by venipuncture of the antecubital vein. Blood was collected in a sterile glass test tube (10 ml) without any anti-coagulant. Immediately test tube was centrifuged using a refrigerated centrifugal machine at 400 g for 12 min. Because of differential densities, it resulted in the separation of three basic fractions: a base of red blood cells at the bottom, acellular plasma on the surface, and finally a PRF clot between the two. A total of 2–3 ml of the top layer was pipetted out with the sterile dropper; the middle layer (PRF) was removed and placed in a sterile dappen dish.

One part of PRF along with beta-tricalcium phosphate (β-TCP) was placed in the furcation defect. The other part of PRF after preparing membrane, was placed over the furcation defect. Mucoperiosteal flaps were sutured back using interdental interrupted sutures. Surgical proce-dure for control group was identical to the test group (β-TCP + except the omission of placement of PRF. Antibiotic coverage (Amoxicillin 500 mg three times a day) and analgesic (Ibuprofen 400 mg and Par-acetamol 325 mg three times a day) was prescribed for 5 days post-sur-gical period. Patients were instructed to rinse twice daily with 0.12% chlorhexidine gluconate for 6 weeks. A complete post-operative evalua-tion was performed at 12 month follow up visit and all the clinical pa-rameters were re-assessed.

Statistical analysisStudent’s paired t-test was used to compare data from baseline to

those at 12 months for each treatment group. A comparison between treatment groups at baseline and 12 months post-surgery was accom-plished with student’s unpaired t-test.

ResultsOut of 24 class II furcation defects, 22 defects were located on buc-

cal surfaces while 2 were located on lingual surfaces of mandibular mo-lars. There were no untoward effects, allergy, infection or patient com-plaints related to graft material. None of the selected patients dropped out before the termination of the study.

In general patients showed good oral hygiene throughout the study. Baseline full mouth mean plaque index (PI) score was 0.82 ± 0.13, which at 12 months decreased to 0.67 ± 0.13 in the test group. Baseline full mouth mean plaque index (PI) score was 0.80 ± 0.11, which at 12 months decreased to 0.65 ± 0.12 in the control group. The difference from baseline to 12 months in the test group (0.15 ± 0.001) as well as the control group (0.15 ± 0.001) was found to be statistically significant post-surgical measurement was statistically significant.

The mean papilla bleeding index (PBI) score during 12-month peri-od remained low (<1). Baseline full mouth mean papillary bleeding in-dex (PBI) score was 0.73 ± 0.10, which at 12 months decreased to 0.60 ± 0.09 in the test group. Baseline full mouth mean plaque index (PI) score was 0.71 ± 0.14, which at 12 months decreased 0.54 ± 0.11 in the control group. The difference from baseline to 12 months in the test group (0.13 ± 0.08) as well as the control group (0.17 ± 0.10) was found to be statistically significant post-surgical measurement was statistically significant.

Baseline Characteristics of the sites in the treated groupsThe baseline defect characteristics are presented in Table 1. At base-

line, no statistically significant differences in any of the investigated pa-rameters were observed between the test and control groups, indicating that the randomization process was effective.

Clinical Outcomes at 12 MonthsStudent’s paired t-test indicated that both the test (HA and

β-TCP+PRF) and control (HA and β-TCP) groups showed significantly greater mean PPD reduction of 2.0 ± 0.73 mm and 0.50 ± 0.52 mm re-spectively at 12 months compared to baseline (Table 1).

On analysis of differences in mean PPD reductions for the test group versus control group at 12 months by Student’s unpaired t-test, statisti-cally significant greater probing depth reduction of 1.50 ± 0.90 mm was observed in the test group as compared to the control group.

The observed differences between baseline CAL and 12 months

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CAL were analyzed by Student’s paired t-test, and were found to be sta-tistically significant in both the groups. When the differences in CAL gains for the test group (3.0 ± 0.95 mm) versus control group (2.00 ± 0.85 mm) were analyzed by Student’s unpaired t-test, statistically signif-icant difference was observed in favor of the test group (Table 1). The mean CAL gain observed in the test group was 1 ± 1.20 mm greater than the control group.

Increase in gingival recession was not found to be statistically sig-nificant in the test (1.0 ± 1.12 mm) as well as the control group (1.34 ± 1.07 mm), when compared to baseline (Table 1). However, no statisti-cally significant difference was found in increase in gingival recession (0.34 ± 1.43 mm) between the test and control groups.

Statistically significant reductions of horizontal probing depth were recorded for the test group as well as for the control group (Table 1). When comparison was made between the test and control groups using the Student’s unpaired t-test, statistically significant greater reduction of horizontal probing depth was observed in test group, with additional benefit of 0.34 mm (Table 1).

The Frequency analysis of furcation changesComplete furcation closure was achieved at 6 sites (50%) in HA and

β – TCP + PRF group as compared to 2 sites (16.66%) in the HA and β – TCP group. The improvement in horizontal classification from class II to class I was observed at 6 sites (50%) in the HA and β – TCP + PRF group and 6 sites (50%) in HA and β – TCP group. However, 4 sites (33.34%) in HA and β – TCP group remained unchanged (Table 2).

DiscussionSuccessful regeneration of periodontal furcation defects is clinically

defined as the complete elimination of horizontal and vertical defect components by bone fill and improvement in the clinical parameters. For the treatment of mandibular class II furcation defects, extensive studies using diverse materials and therapies have been performed. While some reports demonstrated significant clinical attachment and bone gains, other studies did not show clinical improvement14). Thus, the present investigation was undertaken to compare the effectiveness be-tween PRF in combination with β-TCP with that of β-TCP alone for the treatment of mandibular class II furcation defects in human.

The present study was conducted over a period of 6 months using randomized parallel design. The results in the present studies were ob-tained by comparing test group (β-TCP + PRF) with a control group (β-TCP alone). At baseline, none of the investigated parameters at the sites treated by β-TCP and β-TCP + PRF showed any statistical differ-ence, thus ensuring the same starting point for both the procedures test-

ed. There was no sign of allergy, infection or any other complication in any patients, after the use of β-TCP as well as PRF. During 6 months observation period, the wound healing was uneventful. None of the se-lected patients dropped out before the termination of the study and all the patients were satisfied with the treatment modalities provided to them.

The results of present clinical and radiographic study support the concept that the use of PRF in combination with β-TCP provided added benefits of clinical and statistical significance to the treatment of furca-tion defects. In fact, the clinical attachment gains, the probing pocket depth reduction and horizontal defect depth reduction, were consistently greater than those observed in sites treated with β-TCP alone. Reduction of probing pocket depth in order to limit the risk of local reinfection is a primary goal of periodontal therapy. Shallow pockets have a strong neg-ative predictive value for future disease progression, while deep pockets in treated areas are risk indicators for periodontal disease progression. In the present study, both the groups showed reduction of probing pock-et depth at 6 months post-operatively. The mean PPD reduction obtained in test group was 2.0 mm while as in control group it was 0.50 mm. A statistically significant greater reduction of mean PPD (1.50 mm) was observed in test group compared to the control group. The mean PPD reduction observed in the present study by using β-TCP + PRF are com-parable with other studies reported in the literature on use of PRF in combination with bone grafts. Panda et al.15) reported in their case report mean PPD reduction of 6 mm following application of PRF in combina-tion with an alloplast (Ossifi) for the treatment of infrabony defects at 6 months post-surgery. Sambhav et al.16) reported mean PPD reduction of 4 mm following use of PRF in combination with β-TCP for the treat-ment of Grade II furcation defect at 6 months. Sharma et al.17) reported mean PPD reduction of 4.06 mm after 9 months following application of Autologous PRF alone in the treatment of class II furcation defects. The greater mean probing pocket depth reduction reported by pervious investigators could be explained by the greater initial probing pocket depth in their studies.

Primary efficacy parameters for validation of clinical periodontal re-generation after periodontal therapy is gain in clinical attachment lev-el18-21). The outcome measures to assess periodontal regeneration of fur-cation treated sites, it has become increasingly common to measure attachment gain in vertical and horizontal direction, since the primary goal of furcation therapy is to reduce the magnitude of furcation defect to a size, which is maintainable by routine hygiene method and mechan-ical instrumentation18,21). In the present study, β-TCP + PRF group showed statistically significant clinical attachment gain of 3 mm com-pared to β-TCP group (2 mm) at 6 months. Observations made in the present study with regards to clinical attachment level gain are compa-rable with results reported in the previous studies. Sharma et al.22) evalu-ated the effectiveness of autologous PRF in the treatment of grade II furcation defects and reported gain in clinical attachment level by 2.33 mm at 9 months. Thorat et al.23) in their single center controlled clinical trial investigated the effectiveness of autologous PRF in the treatment of infrabony defect and reported gain in clinical attachment level of 3.69 mm at 9 months.

Table 1. Comparison of measured variables for test and control groupExamination

intervalPPD (Mean ± SD in mm) CAL (Mean ± SD in mm) HPD (Mean ± SD in mm) REC (Mean ± SD in mm)

Test Control Test Control Test Control Test ControlBaseline 3.16 ± 0.57 2.66 ± 0.49 11.41 ± 0.66 10.41± 0.66 3.83± 0.49 3.58 ± 0.51 8.25 ± 0.75 7.75 ± 0.86

At 12 months 1.16±0.38 2.16 ± 0.57 8.41±0.66 8.41 ± 0.51 0.5 ± 0.52 1.83 ± 0.26 7.25 ± 0.75 6.41 ± 0.75Difference 2.0± 0.73 0.50 ± 0.52 3.33± 0.83 2.00 ± 0.85 3.33 ± 0.83 1.75±1.21 1.0±1.12 1.34 ± 1.07

p-value 0.001 S 0.006 S 0.001S 0.001 S 0.001 S 0 S 0.01 S 0.001 S

Table 2. Frequency of clinical furcation changes at 6 months in β-TCP and β-TCP + PRF group

Parameters Control Group(β-TCP Group)

Test Group(β-TCP + PRF Group)

Complete closure (HPD = 0) 2 (16.66%) 6 (50%)Changes from Class II to Class I

(HPD< 3) 6 (50%) 6 (50%)

No change 4 (33.34%) 0 (0%)

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In the present study, significant reduction in mean horizontal probing depth was observed in β-TCP + PRF group (3.33 mm) as well as in β-TCP alone group (1.75 mm). When comparison was made between two groups, significantly greater HPD Reduction was observed in the β-TCP + PRF group (1.58 mm).

The main clinical end point of any given periodontal therapy for the treatment of furcation lesion is the full closure of furcation, or if this cannot be attained then the conversion of deep into shallow lesion14). However, the predictability of these treatment goals is influenced by several factors like patient compliance, defect selection, treatment tech-niques and others24). Thus, there is a need to better understand factors and conditions which may have an influence upon treatment outcome. Consequently, in the present study, analysis was performed in relation to treatment modality. In the present study, the number of class II furcation defects that closed or converted to class I were higher in β-TCP + PRF group compared to β-TCP alone group. At present, there are no data available in the literature on the use of PRF in combination with β-TCP for the treatment of class II furcation defects indicating frequency of clinical furcation changes.

Although there is a sparsity of data on gingival recession following regenerative therapy with the use of β-TCP + PRF for the treatment of furcation defect, the present study showed gingival recession of 1 mm in β -TCP +PRF group and 1.34 mm in β -TCP alone group. When GR was compared in both groups the difference was non-significant (0.34 mm). Findings in the present study with regards to post-surgical gingi-val recession were compared with previously reported studies. Thorat et al.23) in a single center controlled clinical trial investigated the effective-ness of autologous PRF in the treatment of infrabony defects and report-ed 0.81 mm marginal tissue recession after surgery. Sharma and Pradeep22) evaluated effectiveness of autologous PRF in the treatment of infrabony defects and reported 0.79 mm marginal tissue recession at 9 months post-surgery.

The most reliable outcome variable for assessing periodontal regen-eration is human histology. Due to ethical consideration and patient management limitation, no histologic evidence was obtained to establish the proof of true periodontal regeneration. The application of PRF in combination with β-TCP seems a promising method for the treatment of class II furcation defect, although the positive clinical results achieved in the present study need the further support of histologic studies to con-firm the quality of the regenerated tissue.

AcknowledgementWe would like to thank specialist biostatistician for statistical analy-

sis help.

Conflict of InterestThe authors have declared that no COI exists.

References1. Calongne KB, Aichelmann-Reidy ME, Yukna RA and Mayer ET.

Clinical comparison of microporous biocompatible composite of PMMA, PHEMA and calcium hydroxide grafts and expanded polytetrafluoroethylene barrier membranes in human mandibular molar Class II furcations. A case series. J Periodontol 72: 1451-1459, 2001

2. Yukna RA, Evans GH, Aichelmann-Reidy MB and Mayer ET. Clin-ical comparison of bioactive glass bone replacement graft material and expanded polytetrafluoroethylene barrier membrane in treating human mandibular molar class II furcations. J Periodontol 72: 125-

133, 20013. Evans G, Yukna R, Gardiner D and Cambre K, editors. Frequency

of furcation closure with regenerative periodontal therapy. The Jour-nal of the Western Society of Periodontology/Periodontal abstracts; 1996.

4. Luepke PG, Mellonig JT and Brunsvold MA. A clinical evaluation of a bioresorbable barrier with and without decalcified freeze‐dried bone allograft in the treatment of molar furcations. J Clin Periodon-tol 24: 440-446, 1997

5. Camelo MC, Nevins ML and Nevins M. Treatment of Class II fur-cations with autogenous bone grafts and e-PTFE membranes. Int J Periodontics Restorative Dent 20: 233-243, 2000

6. Wallace SC, Gellin RG, Miller MC and Mishkin DJ. Guided tissue regeneration with and without decalcified freeze-dried bone in man-dibular Class II furcation invasions. J Periodontol 65: 244-254, 1994

7. de Obarrio JJ, Ara, uacutez-Dutari JI, Chamberlain TM and Croston A. The use of autologous growth factors in periodontal surgical therapy: platelet gel biotechnology--case reports. Int J Periodontics Restorative Dent 20: 486-497, 2000

8. Carroll R, Arnoczky S, Graham S and O’Connell S. Characteriza-tion of autologous growth factors in Cascade platelet rich fibrin ma-trix (PRFM). Edison, NJ: Musculoskeletal Transplant Foundation, 2005

9. Mazor Z, Horowitz RA, Del Corso M, Prasad HS, Rohrer MD and Dohan Ehrenfest DM. Sinus floor augmentation with simultaneous implant placement using Choukroun’s platelet‐rich fibrin as the sole grafting material: a radiologic and histologic study at 6 months. J Periodontol 80: 2056-2064, 2009

10. Aroca S, Keglevich T, Barbieri B, Gera I and Etienne D. Clinical evaluation of a modified coronally advanced flap alone or in combi-nation with a platelet-rich fibrin membrane for the treatment of ad-jacent multiple gingival recessions: a 6-month study. J Periodontol 80: 244-252, 2009

11. Sclafani AP. Applications of platelet-rich fibrin matrix in facial plas-tic surgery. Facial Plast Surg 25: 270, 2009

12. Szpalski M and Gunzburg R. Applications of calcium phos-phate-based cancellous bone void fillers in trauma surgery. Orthope-dics 25: S601-S609, 2002

13. Lekovic V, Milinkovic I, Aleksic Z, Jankovic S, Stankovic P, Ken-ney E and Camargo P. Platelet‐rich fibrin and bovine porous bone mineral vs. platelet‐rich fibrin in the treatment of intrabony perio-dontal defects. J Periodontal Res 47: 409-417, 2012

14. Sanz M and Giovannoli JL. Focus on furcation defects: guided tis-sue regeneration. Periodontol 2000 22: 169-189, 2000

15. Panda S, Ramamoorthi S, Jayakumar N, Sankari M and Varghese SS. Platelet rich fibrin and alloplast in the treatment of intrabony defect. J Pharm Bioallied Sci 6: 127-132, 2014

16. Sambhav J, Rohit R, Ranjana M and Shalabh M. Platelet rich fibrin (Prf) and β-tricalcium phosphate with coronally advanced flap for the management of grade-II furcation defect. Ethiopian J Health Sci 24: 269-272, 2014

17. Sharma A and Pradeep A. Treatment of 3-wall intrabony defects in patients with chronic periodontitis with autologous platelet-rich fi-brin: A randomized controlled clinical trial. J Periodontol 82: 1705-1712, 2011

18. Gottlow J, Nyman S, Lindhe J, Karring T and Wennström J. New attachment formation in the human periodontium by guided tissue regeneration case reports. J Clin Periodontol 13: 604-616, 1986

190

J.Hard Tissue Biology Vol. 28(2): 185-190, 2019

19. Gottlow J, Karring T and Nyman S. Guided tissue regeneration fol-lowing treatment of recession-type defects in the monkey. J Perio-dontol 61: 680-685, 1990

20. Becker W, Becker BE, Mellonig J, Caffesse RG, Warrer K, Caton JG and Reid T. A prospective multi-center study evaluating perio-dontal regeneration for Class II furcation invasions and intrabony defects after treatment with a bioabsorbable barrier membrane: 1-year results. J Periodontol 67: 641-649, 1996

21. Polson AM, Garrett S, Stoller NH, Greenstein G, Polson AP, Harr-old CQ and Laster L. Guided tissue regeneration in human furcation defects after using a biodegradable barrier: a multi-center feasibility

study. J Periodontol 66: 377-385, 199522. Sharma A and Pradeep A. Autologous platelet-rich fibrin in the

treatment of mandibular degree II furcation defects: A randomized clinical trial. J Periodontol 82: 1396-1403, 2011

23. Thorat M, Pradeep A and Pallavi B. Clinical effect of autologous platelet‐rich fibrin in the treatment of intra‐bony defects: a con-trolled clinical trial. J Clin Periodontol 38: 925-932, 2011

24. Cortellini P, Pini‐Prato G and Tonetti M. Periodontal regeneration of infrabony defects (V). Effect of oral hygiene on long‐term stability. J Clin Periodontol 21: 606-610, 1994