ORIGINAL RESEARCH

https://doi.org/10.5005/jp-journals-10015-2575
World Journal of Dentistry
Volume 16 | Issue 1 | Year 2025

Evaluation of Injectable Platelet-rich Fibrin with Xenograft (Sticky Bone) for the Treatment of Horizontal Bone Defect in Periodontitis by Assessing Bone Fill: A Randomized Controlled Clinical Trial

Savita Abdulpur Mallikarjun¹, Mrudula Iyyakkattil², Archana R Naik³, Pallavi Nanaiah⁴, Pavithra Thangavelu⁵, Ashwin Prabhu⁶

^1,3,4,6Department of Periodontology, Dayananda Sagar College of Dental Sciences, Bengaluru, Karnataka, India

²Consultant Periodontist, Thrissur, Kerala, India

⁵Consultant Periodontist, Bengaluru, Karnataka, India

Corresponding Author: Savita Abdulpur Mallikarjun, Department of Periodontology, Dayananda Sagar College of Dental Sciences, Bengaluru, Karnataka, India, Phone: +91 9845433660, e-mail: savitaam@dscds.edu.in

Received: 01 January 2025; Accepted: 06 February 2025; Published on: 13 March 2025

ABSTRACT

Aim: The aim of the study was to evaluate and compare the efficacy of sticky bone along with intramarrow penetration (IMP) and IMP along with open flap debridement (OFD) in comparison to open flap debridement alone in the treatment of horizontal defects by assessing radiographic bone fill.

Materials and methods: In this randomized controlled clinical trial study, 45 subjects having moderate to deep periodontitis were selected and distributed into group A—sticky bone along with IMP and OFD (Sticky bone + IMP + OFD), group B—open flap debridement along with IMP (OFD + IMP), and group C—OFD. Probing pocket depth (PD) and clinical attachment level (CAL) were recorded at baseline, 3 months, and 6 months after surgery. Radiographic assessment was carried out to measure the periodontal defect depth and defect fill percentage (DF%) at baseline, 3 months, and 6 months using digital radiography.

Results: Six months postoperatively, a significant improvement in clinical and radiographic parameters was observed from baseline in all three groups. Intergroup comparison of PD and CAL showed a significant difference in group A compared to group B and group C, with p < 0.05. The defect depth was statistically significant at the 6-month follow-up in all groups, and DF% showed statistically significant results in group A compared to group B and group C, with p = 0.001.

Conclusion: The present study concluded significant bone fill in group A (sticky bone + IMP + OFD) compared to group B (IMP along with OFD) and group C (OFD alone). Therefore, the application of sticky bone along with IMP for the regeneration of horizontal bone defects can be considered an effective treatment modality.

Clinical significance: The use of i-PRF along with IMP has an added clinical and radiographic benefit in a 6-month follow-up for the regeneration of horizontal bone defects.

Keywords: Horizontal defects, Injectable platelet-rich fibrin, Intramarrow penetration, Open flap debridement, Sticky bone

How to cite this article: Mallikarjun SA, Iyyakkattil M, Naik AR, et al. Evaluation of Injectable Platelet-rich Fibrin with Xenograft (Sticky Bone) for the Treatment of Horizontal Bone Defect in Periodontitis by Assessing Bone Fill: A Randomized Controlled Clinical Trial. World J Dent 2025;16(1):26–31.

Source of support: Nil

Conflict of interest: None

INTRODUCTION

Periodontitis is a chronic inflammatory disease that modifies the topography of bone in addition to reducing its height and also leads to various patterns of bone loss, among which horizontal bone loss is the most common destructive pattern. It is termed a zero-wall defect, and its treatment poses a challenge to clinicians but has received scant attention.¹ As per the literature, horizontal bone loss, with an overwhelming prevalence of 92.2%, received only 3.2% therapeutic modalities, whereas vertical bone loss, with a prevalence of 7.8%, received 96.8% treatment alternatives.²

Several therapeutic interventions have been attempted through the years, including various bone grafts, combinations of membrane and graft materials, and biological substitutes such as enamel matrix protein and recombinant human bone morphogenic protein, which have been evaluated for the treatment of horizontal bone defects. However, the outcomes of these treatment modalities have varied, with different degrees of success, but all studies have shown an enormous success rate in vertical and furcation defects.³^,⁴

Platelet-rich fibrin (PRF) is a derivative of platelet-rich plasma in which autologous platelets and leukocytes are present in a complex fibrin matrix to hasten the healing of soft and hard tissue. It forms a three-dimensional fibrin matrix that can be used as a scaffold for tissue regeneration by acting as a barrier membrane in guided bone and tissue regeneration procedures while simultaneously enriching the wound with healing growth factors.⁵ PRF has a synergistic effect with allografts and xenografts. It contains bone morphogenic protein (BMP), which stimulates bone cells to grow naturally and more rapidly through biological pathways.

The development of an injectable formulation of PRF (termed i-PRF) has been pursued to allow the use of platelet concentrate in a liquid formulation, which can be combined easily with various biomaterials. Contemporary research in the field of dentistry has begun to focus on i-PRF as a regenerative tool with the potential to induce tissue regeneration. The effectiveness of i-PRF with xenograft (sticky bone) in vertical alveolar defects, ridge augmentation for implant placement, and treatment of peri-implantitis has shown positive clinical and radiographic outcomes.⁶^,⁷

i-PRF allows graft materials to be integrated without the use of anticoagulants or additives, resulting in a well-agglutinated “steak” for bone grafting. i-PRF and xenograft together create a biological bone graft, in which the xenograft directs bone cells where to grow bone, and i-PRF stimulates the bone cells to grow rapidly into native bone. Intramarrow penetration (IMP), or intentional drilling of holes through the cortical bone, is used in regenerative periodontal surgical procedures. A few interventional studies have mentioned the effectiveness of PRF along with IMP in the treatment of horizontal bone loss.⁸

A composite of hydroxyapatite and collagen, known as G-graft, was used for the trial with the hypothesis that it may lead to faster bone regeneration and greater density of mature bone.⁹ G-graft is composed of naturally occurring low-crystalline hydroxyapatite with collagen, both of which are of bovine origin.

Hence, this study was conducted to assess the clinical and radiographic effectiveness of i-PRF in comparison to open flap debridement in the treatment of horizontal bone defects.

MATERIALS AND METHODS

Study Design

The study was a prospective, 6-month follow-up, concurrent parallel randomized clinical controlled trial evaluating the clinical and radiologic effects of sticky bone used in the surgical treatment of horizontal bone loss. The study was approved by the Ethical Committee of the Institution, Dayananda Sagar College of Dental Sciences, Bengaluru (IEC No. 32.IRB.2019). The study fulfilled the requirements of the Declaration of Helsinki, as adopted by the 18th World Medical Assembly in 1975 and revised in Edinburgh (2000).

Patient Selection

The study was conducted on 45 subjects with stage 2 and stage 3 periodontitis,¹⁰ including patients referred to the outpatient Department of Periodontics, Dayananda Sagar College of Dental Sciences and Hospital, Bengaluru. They were screened during consultation, and participants were informed about the study’s purpose, design, potential benefits, and possible risks. Written informed consent was obtained before the commencement of the trial. The treatment and follow-up were carried out between September 2020 and January 2022. The modified CONSORT guidelines were followed to report the trial.

Inclusion and Exclusion Criteria

The subjects, aged between 25 and 45 years, diagnosed with stage 2 or stage 3 periodontitis with a probing depth of 5–8 mm and sites with horizontal bone defects observed in digital radiographs, were included in the study. Patients with compromised general health, those who smoked, were pregnant or lactating, or had received periodontal therapy within 6 months prior to the study were excluded.¹¹

Sample Size

The sample size was estimated using G*Power software, version 3.1.9.2. Considering the effect size to be measured (f) at 53%, the power of the study at 80%, and the margin of error at 5%, the total sample size needed was 39. Further, anticipating a 10% attrition during the follow-up period, the sample size was increased to 45. This was divided into three groups of 15 participants each.

Randomization

Block randomization was performed using computer-assisted software for the random allocation of subjects into one of the three groups. The allocations were concealed in opaque, sealed envelopes that were sequentially numbered. An experienced periodontist, blinded to the study procedure, collected all clinical data at baseline and during follow-up visits, while another experienced periodontist carried out the procedure.

Initial Therapy

Initial therapy consisted of scaling and root planing of the involved teeth in the planned quadrant using hand curettes and an ultrasonic device under local anesthesia. A periodontal reevaluation was performed 6 weeks after phase I therapy.

Clinical Measurements

Relative Probing Depth

Relative probing pocket depth (PPD) using a UNC-15 periodontal probe and an acrylic stent was measured at six aspects of each tooth: mesiobuccal, midbuccal, distobuccal, mesiolingual, midlingual, and distolingual. Baseline measurements were recorded, and postintervention follow-up measurements were repeated at 3-month and 6-month intervals.

Relative Attachment Level

Relative clinical attachment level (CAL), using a UNC-15 periodontal probe and an acrylic stent, was measured at six aspects of each tooth: mesiobuccal, midbuccal, distobuccal, mesiolingual, midlingual, and distolingual. Baseline measurements were recorded, and postintervention follow-up measurements were repeated at 3-month and 6-month intervals.

Radiographic Examination

Intraoral periapical radiographs were obtained using the long-cone parallel technique and a phosphor plate with a sensor holder to evaluate the level of the alveolar crest. Radiographs were analyzed using the Carestream CS system.

The level of the alveolar crest was calculated at baseline and postintervention after 3 and 6 months and was stored in the computer for assessment. At baseline, the distance from the cementoenamel junction (CEJ) to the base of the defect (BD) was measured (CEJ to BD). Postoperative measurements from CEJ to the alveolar crest (AC) were taken (CEJ to AC) after 3 and 6 months. Defect fill was determined by subtracting the distance (CEJ to BD) from (CEJ to AC).¹² The defect fill percentage was calculated using the formula.⁸

The standardization of radiographic interpretations was performed by an expert radiologist. Radiographic measurements were conducted using Autodesk AutoCAD 2013 software.

Surgical Interventions

After block randomization, participants were divided into three groups. The surgical procedures followed for groups A, B, and C included anesthetization of the surgical sites with 2% lidocaine (1:80,000). Buccal and lingual sulcular incisions were made, and a full-thickness mucoperiosteal flap was elevated to fully expose the horizontal defects.

In group C, meticulous defect debridement and root planing were performed to remove subgingival plaque, calculus, inflammatory granulation tissue, and pocket epithelium.

In group B, in addition to debridement, IMP was performed using a micromotor handpiece and a round carbide bur with copious irrigation of water at a depth of 0.2 mm (Fig. 1).

Figs 1A to F: Open flap debridement along with IMP: (A) Initial probing depth; (B) Debridement; (C) Intramarrow penetration; (D) Baseline radiographic bone loss; (E) Postoperative 3-month radiograph; (F) Postoperative 6-month radiograph

In group A, following debridement and IMP, sticky bone was placed in the decorticated area as well as at the level of the defect (Fig. 2).

Figs 2A to F: OFD along with IMP and sticky bone: (A) Initial probing depth; (B) IMP; (C) Sticky bone placed; (D) Baseline radiographic bone loss; (E) Postoperative 3-month radiograph; (F) Postoperative 6-month radiograph

To achieve primary closure, direct interrupted sutures with 3-0 nonresorbable silk were placed in all groups. Postsurgical instructions were given. Postoperative care included oral administration of amoxicillin 500 mg every 8 hours for 5 days and diclofenac sodium 50 mg + paracetamol 325 mg every 12 hours for 3 days.

Sutures were removed 1-week postsurgery. Patients were recalled after 1, 3, and 6 months for oral hygiene reinforcement and oral prophylaxis. The clinical parameters PPD, CAL, and defect depth were recorded at 3-month and 6-month follow-up periods.

Statistical Analysis

Statistical Method

Statistical Package for the Social Sciences (SPSS) for Windows, Version 22.0 (Released 2013; Armonk, NY: IBM Corp.), was used to perform statistical analyses. Descriptive analysis of all explanatory and outcome parameters was conducted using frequency and proportions for categorical variables and mean ± SD for continuous variables. The Kruskal–Wallis test, followed by the Mann–Whitney post hoc test, was used to compare the mean study parameters between the three groups at different time intervals. Friedman’s test, followed by the Wilcoxon signed-rank post hoc test, was used to compare the mean study parameters between different time intervals within each study group. The level of significance was set at p < 0.05.

RESULTS

Forty-eight subjects were assessed for eligibility. Among these, 45 subjects (age range: 25–45 years) who met the inclusion criteria were enrolled in the study. Considering the dropouts, the final analysis included 41 subjects. Healing was uneventful in all cases, with no adverse effects. Dropouts are represented in the CONSORT flowchart (Fig. 3).

Fig. 3: CONSORT flowchart

Probing Pocket Depth

On intergroup comparison of mean probing pocket depth (PPD) at baseline, no statistically significant difference (p = 0.28) was observed between group A (5.38), group B (5.57), and group C (5.77). However, at the 6-month postintervention follow-up, a statistically significant difference among all three groups was observed (p < 0.001).

Post hoc analysis revealed a statistically significant reduction in PPD in group A compared to group B (p < 0.001) and group C (p < 0.001) (Table 1).

**Table 1:** Comparison of mean values of different study parameters between three groups at 6 months period using Kruskal–Wallis test followed by Mann–Whitney *post hoc* test
Parameter	Groups	N	Mean	SD	Min	Max	p-value^a	Sig. diff.	p-value^b
PD	Group A	14	2.16	0.23	2	3	<0.001*	A vs B	<0.001*
	Group B	14	2.79	0.44	2	4		A vs C	<0.001*
	Group C	13	3.25	0.25	3	4		B vs C	0.003*
CAL	Group A	14	0.05	0.15	0	1	0.007*	A vs B	0.37
	Group B	14	0.11	0.19	0	1		A vs C	0.009*
	Group C	13	0.40	0.45	0	1		B vs C	0.03*
Defect depth	Group A	14	1.07	0.35	0.8	2.0	0.001*	A vs B	0.008*
	Group B	14	1.60	0.53	0.6	2.5		A vs C	0.002*
	Group C	13	2.04	0.82	0.3	3.4		B vs C	0.04*

^ap-value derived by Kruskal–Wallis test; ^bp-value derived by Mann–Whitney’s post hoc test

On intragroup comparison, the mean PPD at baseline and 6 months postintervention showed a statistically significant reduction within each group (p < 0.001).

Clinical Attachment Level

The mean clinical attachment level (CAL) at baseline in the three groups was similar, with no statistically significant difference (p = 0.26). However, at the 6-month follow-up, a statistically significant difference was observed among all three groups (p = 0.007).

Post hoc analysis revealed a statistically significant gain in CAL in group A compared to group B and group C (p = 0.009) (Table 1).

Intragroup comparison of CAL in each group showed a statistically significant gain (p < 0.001) from baseline to the 6-month postintervention follow-up.

Defect Depth

On intergroup comparison of mean defect depth (DD) at baseline, no statistically significant difference (p = 0.64) was observed between group A (2.72), group B (2.76), and group C (2.92). However, at the 6-month follow-up, a statistically significant difference among all three groups was observed (p = 0.001).

Post hoc analysis revealed a statistically significant reduction in DD between group A and group C (p = 0.002), followed by group A and group B (p = 0.008), and between group B and group C (p = 0.04) (Table 1).

Intragroup comparison of DD in each group showed a statistically significant reduction (p = 0.001) from baseline to the 6-month follow-up.

Defect Fill Percentage

The DF% was calculated based on the linear radiographic depth of the defect obtained from PSP using the following formula.⁸

The mean DF% in group A was 61.09%, compared to group B and group C, which showed DF% values of 42.93 and 33.08%, respectively (p < 0.001). Post hoc analysis revealed a highly statistically significant difference between group A and group C (p < 0.001) (Table 2).

**Table 2:** Comparison of mean percentage of defect fill between 3 groups using Kruskal–Wallis test followed by Mann–Whitney *post hoc* test
Time	Groups	N	Mean	SD	Min	Max	p-value^a	Sig. diff.	p-value^b
6 months	Group A	14	61.09	9.75	33.3	71.4	<0.001*	A vs B	0.001*
	Group B	14	42.93	12.55	6.7	59.3		A vs C	<0.001*
	Group C	13	33.08	13.69	16.7	75		B vs C	0.004*

*Statistically significant; ^ap-value derived by Kruskal–Wallis test; ^bp-value derived by Mann–Whitney’s post hoc test

At the 6-month postintervention follow-up, the test group (group A) showed statistically significant improvement in both clinical and radiographic parameters compared to the other groups. The use of sticky bone along with IMP is an effective treatment modality for improving bone fill in horizontal alveolar bone defects associated with periodontitis.

DISCUSSION

This study was conducted to evaluate the efficacy of i-PRF plus bone graft (sticky bone) along with IMP in the treatment of horizontal defects in chronic periodontitis subjects.

Platelet-rich fibrin (PRF) is a second-generation PC that was formerly described by Choukroun and Ghanaati.¹³ Over the past decade since PRF was developed, many clinicians have observed the potential use of a liquid version of PRF termed injectable PRF. Choukroun and Ghanaati systematically analyzed the effect of relative centrifugation force on leukocytes, platelets, and growth factor release within injectable PRF matrices. It was reported that the low-speed centrifugation concept enhances growth factors, platelets, and leukocytes within injectable PRF matrices.¹³ The current study used 3,300 rpm for 2 minutes to obtain i-PRF for the preparation of sticky bone, according to the technical notes given by Mourão et al.¹⁴ Since i-PRF is a novel invention, most of the research in regenerative therapy has been conducted in animal studies and clinical trials in the field of advanced surgical procedures in implantology. The present study, as per a systematic literature search, was the first of its kind where sticky bone had been evaluated clinically and radiographically in the treatment of horizontal defects.

In the current study, group A, in which sticky bone along with IMP and OFD was performed, exhibited a highly significant reduction in the mean PD (3.2 ± 0.39) and CAL gain (2.52 ± 0.46) at the 6-month follow-up. Approximately, 61.09% of DF was observed in group A, which was highly statistically significant compared to group B and group C. Interestingly, in this study, we found highly significant improvements in both clinical and radiographic parameters in group A when compared to group B and group C.

IMP is the removal of cortical bone to expose cancellous bone, thereby enhancing the healing process by promoting bleeding and allowing progenitor cells and blood vessels to reach the bone-grafted site more readily.¹⁵ In the experimental group B, IMP along with OFD was performed, wherein a mean PD reduction of 2.83 ± 0.17 and CAL gain of 0.55 ± 0.31 at the 6-month follow-up were noted. These findings were similar to the studies conducted by Debnath and Chatterjee⁸ and Crea et al.,¹⁶ wherein the mean PD reduction and mean CAL gain of >2 mm in the test site were statistically significant.

The bone defect fill at the 6-month follow-up was 42.93% in group B, which was comparatively higher than the mean DF (39.02%) in the study conducted by Debnath and Chatterjee.⁸ Ghaysh evaluated the contribution of IMP to the outcomes of OFD for the treatment of intrabony defects, which revealed a significant reduction in the defect depth from baseline to the 6-month follow-up (13.6 ± 2.79).¹⁵

This is the first study in which a comparison of i-PRF (sticky bone) along with IMP and OFD was evaluated in the treatment of horizontal bone defects. Although a statistically significant difference was observed in clinical and radiographic parameters in all three groups, group A (i-PRF + IMP) exhibited much better results in terms of improvement in clinical parameters and defect fill, with a higher marginal bone level at the 6-month follow-up.

The PD and CAL evaluated in the study at baseline were equivalent in all study groups. At the 6-month follow-up, a significant reduction in PD, as well as a gain in CAL, was obtained in group A, which was statistically significant compared to group B and group C. Although intergroup comparison stated group A to be statistically significant compared to group B and group C, this was attributed to the potential role of sticky bone as a biomaterial. Sticky bone stabilizes the bone graft in the horizontal defect site, thereby accelerating tissue healing and minimizing bone loss during the healing phase. The moldable nature of sticky bone allows it to adapt appropriately to the horizontal bone defect, thus preventing the micro- and macromovement of the graft particles. Hence, the volume of augmentation was maintained during the healing period, and the fibrin interconnection minimized soft tissue ingrowth into the sticky bone graft.

Majzoub et al. stated that the incorporation of IMP into the surgical site generates a close spatial association between angiogenesis and bone formation; therefore, the companionship of IMP cannot be evicted.¹⁷ The vessel-rich medullary opening space facilitates capillary sprouting and improves vascular supply into the surgical site. A local increase in bone morphogenetic proteins and other growth factors from the decorticated surface, endosteal area, and ruptured vessel area can further enhance new bone formation. Thus, the statistically significant difference observed in group A was due to the synergistic effect of sticky bone and IMP.¹¹ The use of sticky bone along with IMP in the treatment of horizontal defects presents better clinical and radiographic outcomes. Further intergroup comparison of sticky bone along with IMP showed a significantly higher difference compared to IMP alone. However, in terms of the percentage of defect fill, group A showed better results than group B, which could be attributed to the ability of i-PRF to release higher concentrations of various growth factors and induce higher fibroblast migration and expression of PDGF, TGF-β, and collagen 1, as well as its higher BMP and cytokine release.¹⁸ Furthermore, the use of a bone graft contributed to the improvement in defect depth reduction from baseline to 6 months.

The main limitations of the current study include the small sample size and the 6-month follow-up. Considering the limitations of the present study, a greater number of multicenter trials and longitudinal, prospective studies with longer follow-ups should be carried out in different ethnic groups with a larger sample size to determine the efficacy of i-PRF (sticky bone) in horizontal defects with standard clinical parameters.

CONCLUSION

The results of the present study suggest that the addition of sticky bone and IMP to an OFD procedure used to treat horizontal defects could result in a significant improvement in clinical and radiographic outcomes in well-maintained periodontal patients, with particular benefits in terms of radiographic bone fill. Horizontal defects, being the most prevalent form of periodontal defects, demand more attention from researchers, and the use of autologous growth factor delivery systems in the form of i-PRF offers a new dimension in their management.

REGISTRATION

The trial is registered with the Clinical Trial Registry of India (CTRI). The registration number for this trial is CTRI/2022/04/042145.

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