Role of placental extracts in enhancing periodontal flap surgery healing: insights from periostin biomarker analysis

Abstract

Background

The elimination of the causative agent and the facilitation of tissue regeneration are the fundamental objectives of periodontal therapy. Various adjunctive agents have been investigated to optimize treatment outcomes with surgical interventions. Periostin is a matricellular protein predominantly expressed in periodontal tissues, playing a key role in tissue remodeling, inflammation, and wound healing. The human placental extract has been used in periodontal surgery and compared with open flap debridement alone, with gingival crevicular fluid (GCF) periostin levels assessed to gauge periodontal wound healing.

Methods

Sixteen systemically healthy patients diagnosed with Stage III Grade C periodontitis were enrolled in the study. Participants were randomly assigned to either the test group (n = 8) or the control group (n = 8), with a total of nine males and seven females distributed across the groups. The test group underwent open flap debridement (OFD), followed by applying human placental extract gel absorbed into a gelatin sponge, while the control group received only OFD. Clinical parameters were assessed at baseline and 3 month post-treatment. GCF periostin levels were measured at baseline, 6 weeks, and 3 months.

Results

The test group demonstrated a mean probing pocket depth (PPD) reduction of 4.75 ± 1.28 mm, compared to 3.12 ± 1.12 mm in the control group, with the difference being statistically significant. The relative attachment level (RAL) gain was 4.37 ± 1.18 mm in the test group and 2.75 ± 0.70 mm in the control group; however, this difference was not statistically significant. At 3 months, the mean healing index score was 4.50 ± 0.53 in the test group and 3.62 ± 0.51 in the control group, with a statistically significant intergroup difference. The Plaque Index (PI), Gingival Index (GI), and Gingival Bleeding Index (BI) showed moderate reductions at 3 months; however, intergroup differences were not statistically significant, except for BI, where the difference at 3 months was -0.180.

Conclusions

The adjunctive use of placental extract gel in surgical periodontal therapy demonstrated beneficial effects on healing outcomes. In addition, periostin shows promise as a biomarker for periodontal wound healing.

Introduction

According to the 2017 World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions, periodontitis is defined as “the loss of periodontal attachment due to microbially associated and host-mediated inflammation” [1] .The progression and outcome of the periodontal disease depend on the complex interplay between pathogenic agents, the host's defence mechanisms, and environmental factors. A deeper understanding of this relationship is essential for effectively managing and treating periodontal disease [1].

The primary goal of periodontal therapy is to eliminate the causative agent and promote periodontal healing. Depending on the severity of the condition, both non-surgical and surgical treatments may be employed. However, successful periodontal regeneration requires a complex interaction of various intrinsic components, including interleukins and growth factors, which play a crucial role in tissue repair and recovery [1].

The human placenta is a rich source of bioactive molecules, including glycosaminoglycans, nucleic acids, polydeoxyribonucleotides, hormones, and proteins, all with significant therapeutic potential. Since its initial use in the 1950s, numerous clinical trials have explored its applications across various medical fields [2].

Gingival crevicular fluid (GCF) is a reservoir of proteins, enzymes, cytokines, mediators, and immunoinflammatory and bacterial cellular components originating from periodontal tissues and peripheral blood. As a non-invasive diagnostic tool, GCF provides valuable insights into periodontal dynamics and the progression of periodontitis [3].

Periostin is a critical protein involved in wound healing and periodontal tissue repair. It plays a key role in maintaining hemostasis in the periodontal ligament (PDL). In chronic periodontal disease, the proliferation and differentiation of PDL cells are significantly impaired, leading to reduced tissue integrity and compromised regeneration [4]. However, periostin is a biomarker for reconstructive cellular matrix interactions and cell behaviour in matrix biomechanics during surgical periodontal therapy. It helps maintain hemostasis and supports the structural integrity of connective tissues [4]. Therefore, periostin can be a reliable indicator for assessing periodontal healing.

This study aims to evaluate the adjunctive use of placental extract in surgical periodontal therapy compared to surgical treatment alone, focusing on assessing GCF periostin levels as a marker of periodontal healing.

Materials and methods

Study design

This study was designed as a prospective, randomized, controlled clinical trial. The study protocol was reviewed and approved by the Institutional Review Board of Krishnadevaraya College of Dental Sciences and the Hospital Ethical Committee (REF: Ethical Comm/015/2020–21). This clinical trial was registered on ClinicalTrials.gov with the identifier NCT05936426 and protocol ID 02_D012_112276 before the initiation of the study procedures. The study adhered to the ethical principles outlined in the World Medical Association Declaration of Helsinki (Version VI, 2002). All participants completed an initial phase of therapy, which included oral hygiene instructions, scaling, and root planning.

Source of data

Patients visiting the Department of Periodontology, Outpatient Section, Krishnadevaraya College of Dental Sciences and Hospital, Bangalore, India were randomly recruited based on predefined inclusion and exclusion criteria.

Method of collection of data

The patients were randomly assigned into two treatment groups (test and control). The treatment allocation to the test and control group was assigned employing a sealed envelope containing a code derived from a computer-generated randomized list to receive either: test group (n = 8): surgical periodontal therapy with adjunctive placental extract. Control group (n = 8): surgical periodontal therapy alone.

Patients between the age group of 25–55 years, with, Stage 3, Grade C periodontitis with probing pocket depth (PPD) ≥ 6 mm and presence of alveolar defect were allotted for the study. Systemically healthy subjects who are compliant, have not received any periodontal treatment in the last 6 months, and have had anti-microbial therapy in the past 3 months were included. Teeth with pulpal/periapical involvement or having poor prognosis, smokers, pregnant/lactating females, and patients with known systemic diseases/conditions precluding any elective surgery were excluded from the study.

The eligible subjects who volunteered were informed of the nature, potential risks, and benefits of their participation in the study and a written sign of informed consent was obtained from those who agreed to participate. The following clinical measurements: probing pocket depth (PPD), relative attachment level (RAL), Plaque Index [5], Gingival Index [6], Gingival Bleeding Index [7], Healing Index [8], and GCF periostin levels.

Surgical procedure

The operative sites were anaesthetized using 2% lignocaine hydrochloride with adrenaline (1:180,000). Crevicular incisions were made on each tooth segment's facial and lingual/palatal surfaces using a Bard–Parker No. 15 blade.

A full-thickness mucoperiosteal flap was elevated using a periosteal elevator, ensuring maximal tissue preservation. After flap reflection, granulation tissue was meticulously removed. Root surfaces were thoroughly debrided and smoothed. The flap was trimmed to remove residual tissue tags, ensuring optimal healing.

The flap was repositioned and secured using interrupted sutures (Mersilk 3–0). Finally, a periodontal dressing was applied over the surgical site to protect the area and promote healing.

Delivery of placental extract [9]

In Group A (test group), following open flap debridement, 1 mL of human placental extract gel (Placentrex®, the original research product of Albert David Limited, India—a drug derived from fresh, full-term, healthy human placentae) was dispensed into a dappen dish.

Gelatin foam (Abgel, Sri Gopal Krishna Labs, Pvt. Ltd., India) (Fig. 1) was cut into small beads (1 mm² each) and allowed to soak in the placental gel for a few seconds (Fig. 2). These gelatin beads, impregnated with the gel, were placed at the surgical site using a graft carrier and condensed into the defect area. To prevent excessive spillover of the gel, gentle pressure was applied over the flap using moist gauze. Any excess gel was removed, and Coe–Pak was placed to secure the site (Fig. 3).

Fig. 1.

Absorbable gelatin sponge

Fig. 2.

Gelatin foam (A) and Gelatin foam fragments soaked in placental gel (B)

Fig. 3.

Surgical procedure for test group: (A) sulcular incision given, (B) flap reflection and debridement done, (C) placement of the placental extract soaked in gelatin sponge, (D) sutures placed, and (E) periodontal dressing placed

In Group B (control group), this step was omitted after open flap debridement. Post-operative medications were non-steroidal anti-inflammatory drugs (Tab Ibuprofen 400 mg thrice daily for 3 days) and Antibiotics (Cap Amoxicillin 500 mg thrice daily for 3 days) after meals. If patients were allergic to penicillin, they were given Cap Clindamycin 300 mg three times daily for 3 days. Post-surgery ice pack application every 20 min per hour and abstinence from hot food and drinks were advised for the next 3 h. A 1-week soft diet and mouth rinse (15 mL chlorhexidine 0.12%) twice a day for 1-min duration for 2 weeks was prescribed. After 2 weeks, periodontal pack and sutures were removed. Clinical parameters were recorded at baseline and 3 months after surgical procedure.

Gingival crevicular fluid (GCF) sample collection

GCF samples were collected using periopaper strips (PerioCol, OraFlow, Inc., USA) from all 16 patients (Groups A and B) at baseline, 6 weeks, and 3 month post-surgery.

The collected GCF samples were stored at − 80 °C until further analysis for periostin levels using an Enzyme-Linked Immunosorbent Assay (ELISA). The assay was performed using the human periostin (POSTN) ELISA Kit (Abbkine), which has a 9 ng/mL sensitivity.

Statistical analysis

Using statistical power analysis G*Power software (version 3.1.9.2) and considering t tests and means: difference between two independent means (two groups):

The total sample size (n) for the current study was estimated to be 16 by maintaining.

• α error as 0.05 at 95% CI,

• β error as 0.10,

• The power of the test (1-β error) was 90%,

• Allocation ratio N2/N1as 1

• Effect size (Cohen's d statistic) as 1.751 (determined from Sharma A et al. 2020) [9].

The required sample size for the current study with 90% power was 8 samples per group. A total sample size of 16 (n) was equally distributed in each of the two groups (test and control group) for the assessment of probing pocket depth, relative attachment level, plaque index, gingival index, gingival bleeding index, healing index and GCF periostin levels. Therefore, a total of 8 samples per group (surgical periodontal therapy with adjunctive placental extract as the test group and surgical periodontal therapy alone as the control group) was included to assess each property.

Results

This prospective, randomized, controlled clinical trial was designed to assess healing after periodontal flap surgery using periostin levels in gingival crevicular fluid, with and without the use of placental extracts. A total of 30 participants were recruited, of whom 16 were followed for 3 months and considered for analysis. The participants, aged between 36 and 54 years, included 9 males and 7 females, all with a probing depth (PD) of ≥ 6 mm and meeting the predetermined inclusion criteria.

Demographic findings

The demographic parameters studied are represented in Figs. 4 and 5. The mean PPD in the test group at baseline was 8.50 ± 1.06 and 3.75 ± 1.03 at 3 months, and in control, the group was 7.87 ± 1.45 and 4.75 ± 0.70, respectively.

Fig. 4.

Age distribution of the study population

Fig. 5.

Gender distribution of the study population

Intragroup comparison of the PPD in the test and control groups was carried out using a paired t test (Table 1), which shows p value ≤ 0.05. Thus, the data are considered to be statistically significant (p = 0.000). Intergroup comparison of the PPD between the test and control group was carried out using the independent t test (Table 2), which shows p value ≤ 0.05. Thus, the data are considered to be statistically significant (p = 0.041). The mean RAL in the test group at baseline was 8.50 ± 1.06 and 4.12 ± 1.24 at 3 months, and in the control group was 8.25 ± 2.43 and 5.50 ± 2.32, respectively.

Table 1.

Intergroup comparison of the mean values of clinical parameters at baseline and 3 months between test and control group

Clinical Parameters	Groups	Mean ± SD	Mean difference	95% Confidence Interval of the difference		df	Independent t test value	p value
				Lower	Upper
PPD in mm At baseline	Test	8.50 ± 1.06	0.625	− 0.745	1.995	14	0.978	0.345
	Control	7.87 ± 1.45
At 3 months	Test	3.75 ± 1.03	− 1.000	− 1.950	− 0.049	14	− 2.256	0.041*
	Control	4.75 ± 0.70
RAL in mm At baseline	Test	8.50 ± 1.06	0.250	− 1.764	2.266	14	0.266	0.794
	Control	8.25 ± 2.43
At 3 months	Test	4.12 ± 1.24	− 1.375	− 3.378	0.628	14	−1.472	0.163
	Control	5.50 ± 2.32

^*Statistically Significant (p ≤ 0.05)

Table 2.

Intergroup comparison of the mean values of Plaque Index, Gingival Index. Gingival Bleeding Index at baseline and 3 months between test and control group

Clinical Parameters	Timeline	Groups	Mean +  SD	Mean difference	95% Confidence Interval of the difference		df	Independent t test value	p value
					Lower	Upper
PLAQUE INDEX SCORE	At Baseline	Test	1.62 ± 0.32	− 0.048	− 0.461	0.363	14	− 0.253	0.804
		Control	1.67 ± 0.43
	At 3 months	Test	0.70 ± 0.17	− 0.090	− 0.296	0.116	14	− 0.933	0.367
		Control	0.79 ± 0.20
GINGIVAL INDEX SCORE	At Baseline	Test	1.44 ± 0.24	− 0.066	− 0.438	0.305	14	− 0.382	0.708
		Control	1.51 ± 0.42
	At 3 months	Test	0.57 ± 0.27	− 0.212	− 0.5103	0.0853	14	− 1.530	0.148
		Control	0.78 ± 0.28
GINGIVAL BLEEDING INDEX SCORE	At Baseline	Test	0.83 ± 0.22	0.178	− 0.026	0.384	14	1.864	0.083
		Control	0.65 ± 0.15
	At 3 months	Test	0.20 ± 0.14	− 0.180	− 0.332	− 0.028	14	− 2.539	0.024*
		Control	0.38 ± 0.14

^*Statistically Significant (p ≤ 0.05)

Intragroup comparison of the RAL in the test and control groups was done using a paired t test (Table 2), which shows p value ≤ 0.05. Thus, the data are considered to be statistically significant (p = 0.000). Intergroup comparison of the RAL was carried out using the independent t test (Table 2), which shows a p value ≥ 0.05. Thus, the data are considered not statistically significant (p = 0.794) and (p = 0.163). In addition, the mean PPD across the study groups is depicted in Fig. 6.

Fig. 6.

Comparison of mean probing pocket depth across the study groups

The mean plaque index score in the test group at baseline was 1.62 ± 0.32 and 0.70 ± 0.17 at 3 months. Similarly, the control group had 1.67 + 0.43 and 0.79 + 0.20, respectively. Intragroup comparison of the mean plaque index score was carried out using a paired t test (Table 2), which shows p value ≤ 0.05. Thus, the data are considered to be statistically significant (p = 0.000). An independent t test was carried out for an intergroup comparison of the mean plaque index scores (Table 3), which shows a p value ≥ 0.05. Thus, the data are not statistically significant (p = 0.804) (p = 0.367).

Table 3.

Intergroup comparison of the Healing Index Scores at 3 months

Groups	N	Mean ± SD	Median	Min.–Max	Mean Rank	Sum of Ranks	Mann–Whitney U test value	p value
Test group	8	4.50 ± 0.53	4.50	4–5	11.25	90.00	10.000	0.021*
Control group	8	3.62 ± 0.51	4.00	3–4	5.75	46.00
Total	16	4.06 ± 0.68	4.00	3–5

^*Statistically Significant (p ≤ 0.05)

The mean gingival index scores in the test group at baseline were 1.44 ± 0.24 and 0.57 ± 0.27 at 3 months, and in the control group, the group was 1.51 ± 0.42 and 0.78 ± 0.28, respectively. Intragroup comparison mean in the test and control groups was carried out using a paired t test (Table 2), which shows p value ≤ 0.05. Thus, the data are considered to be statistically significant (p = 0.000). Intergroup comparison of the mean gingival index scores was carried out using an independent t test (Table 3), which shows a p value ≤ 0.05. Thus, the data are considered not statistically significant (p = 0.708), (p = 0.148).

The mean gingival bleeding index scores in the test group at baseline were 0.83 ± 0.22 and 0.20 ± 0.14. Similarly, in the control group, it was 0.65 ± 0.15 and 0.38 ± 0.14, respectively. Intragroup comparison of the mean gingival bleeding index scores in the test and control groups was carried out using a paired t test (Table 3), which shows p value ≤ 0.05. Thus, the data are considered statistically significant (p = 0.000) (p = 0.001). Intergroup comparison of the mean gingival bleeding index scores was carried out using an independent t test (Table 2), which shows p value ≤ 0.05. Thus, the data are considered statistically significant at 3 months (p = 0.024).

The mean healing index score was analyzed using the Mann–Whitney U test (Table 3) in the test group, which was 4.50 ± 0.53 and 3.62 ± 0.51 in the control group, which shows a p value ≤ 0.05. Thus, the data are considered to be statistically significant (p = 0.021). The distribution of healing index scores across the study groups is shown in Fig. 7.

Fig. 7.

Distribution of Healing Index scores across the study groups

Intergroup comparison was carried out using a chi-square test, showing that the score GOOD was 18.8% in the control group, VERY GOOD was 25% in the test group and 31.2% in the control group, EXCELLENT was 25% in the test group. The p value was ≤ 0.05. Thus, the data are considered to be statistically significant (p = 0.029).

The GCF periostin levels in each group between various follow-ups were analyzed using Repeated Measures of ANOVA. The mean GCF periostin levels in the test group at baseline were 1.49 ± 0.69, 4.16 ± 0.46 at 6 weeks and 4.03 ± 0.45 at 3 months. The mean GCF periostin levels in the control group at baseline were 1.47 ± 0.89, 2.95 ± 0.38 at 6 weeks, and 2.72 ± 0.42 at 3 months. Intergroup comparison of the mean values of GCF periostin concentration between the study groups was carried out using an independent t test (Table 4), which shows p values ≤ 0.05 among the study groups. Thus, the data are considered statistically significant. This indicates that GCF POSTN concentration decreases with the increasing grade of inflammation during periodontal disease, and their levels increase after treatment and resolution of inflammation.

Table 4.

Intergroup comparison of the GCF periostin level at baseline, 6 weeks and 3 months between test and control group

GCF Periostin level (pg/ml)	Groups	Mean ± SD	Mean differ ence	95% Confidence Interval of the difference		df	Independent t test value	p value
				Lower	Upper
At Baseline	Test group	1.49 ± 0.69	0.024	− 0.83454	0.88279	14	0.060	0.953
	Control group	1.47 ± 0.89
At 6 weeks	Test group	4.16 ± 0.46	1.215	0.76109	1.66941	14	5.739	0.000*
	Control group	2.95 ± 0.38
At 3 months	Test group	4.03 ± 0.45	1.308	0.83809	1.77816	14	5.969	0.000*
	Control group	2.72 ± 0.42

^*Statistically significant (p ≤ 0.05)

Pearson's correlation coefficient test was done to check for any correlation between the GCF periostin concentrations with the clinical parameters at 3 months in all the study groups (Table 5). The distribution of GCF periostin levels across various study groups is illustrated in Fig. 8. The results show a positive correlation between the periostin levels and the clinical parameters PPD, RAL, PI, and HI of all study groups and a negative correlation with the GI and BI. No statistically significant difference was found between the GCF periostin levels and clinical parameters at 3 months in the test and control group (p =  ≥ 0.05). Thus, POSTN was detected in GCF samples of all the subjects who participated in the study. The quantified results confirmed the hypothesis that GCF POSTN concentration decreases with the increasing grade of inflammation during periodontal disease, and their levels increase after treatment and resolution of inflammation.

Table 5.

Intergroup comparison association of GCF periostin levels and clinical parameters at 3 months in the test and control groups

GCF periostin Levels at 3 months		At 3 months
		PPD	RAL	PI	GI	BI	HI (Spearman’s Correlation Coefficient - rho)
Test group	Pearson Correlation Coefficient (r)	0.449	0.403	0.158	− 0.590	− 0.409	0.327
	p value	0.264	0.322	0.708	0.123	0.315	0.429
Control group	Pearson Correlation Coefficient (r)	0.321	0.219	0.289	−0.197	−0.445	0.057
	p value	0.438	0.602	0.487	0.641	0.269	0.894

^*Statistically significant (p ≤ 0.05)

Fig. 8.

Distribution of GCF periostin levels across the study groups

Discussion

The prevalence of periodontitis worldwide is nearly 90%, and the ultimate fate of teeth affected is their eventual loss. A complex interplay of etiological agents is responsible for periodontal disease, with bacteria in the form of plaque around the teeth being the primary culprit^. [9] A complex interplay of etiological agents is responsible for periodontal disease, with bacteria in the form of plaque around the teeth being the primary culprit [9]. Periodontal therapy can be categorized as either graft-associated or non-graft-associated. While graft-associated surgery aims to achieve true regeneration, this objective remains a clinical challenge. To enhance regenerative outcomes, various biologic agents such as bone morphogenetic proteins (BMPs), Emdogain, growth factors, and platelet-rich concentrates have been used as adjuncts. More recently, human placental extracts have emerged as a promising addition to this group. [10]

Placental extracts are widely used in general surgery for treating non-healing wounds, burns, post-surgical dressings, and bedsores, primarily due to their fibronectin type III peptide-mediated healing properties [10]. The healing outcomes observed in the present study, assessed through periostin concentrations in gingival crevicular fluid, suggest a potential benefit of incorporating placental extract in periodontal flap procedures. To increase the substantivity of placental extract, it was adsorbed onto ABGEL (Absorbable Gelatin Sponge USP), a non-toxic, non-allergenic, non-immunogenic, and non-pyrogenic hemostat. ABGEL absorbs 40–50 times its weight in blood, ensuring hemostasis, and is completely absorbed within 3–5 weeks in vivo. [10]

The test group showed a mean PPD reduction from 8.50 ± 1.06 mm at baseline to 3.75 ± 1.03 mm at 3 months, while the control group reduced from 7.87 ± 1.45 mm to 4.75 ± 0.70 mm. The mean RAL gain was 4.37 ± 1.18 mm in the test group and 2.75 ± 0.70 mm in the control group, with intergroup differences being statistically significant. As placental extract gel is a relatively newer regenerative agent in periodontal flap surgery, direct comparisons are lacking. However, Sharma et al. reported a PPD reduction of 1.5 mm and RAL gain of 1.3 mm using placental extract gel as a local adjunct to SRP [10]. Similarly, an animal study found that PEG-enhanced SRP resulted in superior epithelial and alveolar bone formation, better periodontal ligament organization, new vascularization, and reduced TNF-α expression, improving healing. [11]

Periostin, produced by fibroblasts, is essential for periodontal regeneration and is highly expressed in collagen-rich connective tissues [12]. The test group showed periostin levels of 1.49 ± 0.69 ng/mL at baseline, 4.16 ± 0.46 at 6 weeks, and 4.03 ± 0.45 at 3 months. The control group had levels of 1.47 ± 0.89 at baseline, 2.95 ± 0.38 at 6 weeks, and 2.72 ± 0.42 at 3 months. The intergroup differences were statistically significant. These findings align with Rezaei et al., [13] who reported baseline periostin levels of 1.34 ± 0.53 ng/mL in periodontitis patients with coronary heart disease. Similarly, Padial-Molina et al. observed periostin elevation at 48 h and 2 week post-surgery, suggesting its role in healing [14]. In the present study, periostin levels peaked at 6 weeks and slightly declined at 3 months, likely due to collagen maturation and extracellular matrix stabilization. Balli et al. also reported an inverse relationship between periostin and periodontal disease severity, similar to the negative correlation between periostin levels and GI (− 0.590, − 0.197) and BI (− 0.409, − 0.445) at 3 months. [15]

Since connective tissue healing takes approximately 7 weeks, periostin levels at 3 months provide valuable insights. [16] As inflammation subsides post-surgery, periostin levels rise to support cell migration, proliferation, and extracellular matrix restructuring before gradually returning to baseline. In this study, periostin levels at 6 weeks were significantly higher in the test group (4.16 ± 0.46) than in the control group (2.95 ± 0.38) and remained elevated at 3 months (4.03 ± 0.45 vs. 2.72 ± 0.42), further emphasizing the adjunctive effect of placental extract.

Owing to paucity of available studies on periostin levels following OFD with Placentrex gel, direct comparisons are limited. However, Morsy et al. demonstrated reduced TNF-α levels with placental extract gel in SRP, supporting its anti-inflammatory properties. Similar implications can be drawn regarding periostin, which increases as inflammation resolves and healing progresses. [11]

At 3 months, the mean healing index score was 4.50 ± 0.53 in the test group and 3.62 ± 0.51 in the control group, with intergroup differences being statistically significant. In the test group, 25% of cases were rated “EXCELLENT” and 25% “VERY GOOD,” while in the control group, 31.2% were “VERY GOOD” and 18.8% “GOOD,” indicating superior healing in the test group. This could be attributed to placental extract's anabolic tissue repair effects, which enhance cell proliferation, immunomodulation, and regeneration. [17]

Morsy et al. (2022) also evaluated Placentrex gel for recurrent aphthous stomatitis, finding significant pain and ulcer size reductions within 7 days. [11] In addition, Akagi et al. demonstrated that placental extracts promote collagen type-1 synthesis in human gingival fibroblasts, further supporting their regenerative potential. [18]

Plaque Index (PI), Gingival Index (GI), and Gingival Bleeding Index (BI) showed moderate reductions over 3 months, with the BI intergroup comparison reaching statistical significance (− 0.180). This could be due to the anti-inflammatory and anti-platelet properties of placental extract, contributing to reduced gingival bleeding [18]. Overall, OFD with adjunctive placental extract gel significantly improved clinical parameters, highlighting its potential as a regenerative agent. As a healing biomarker, periostin demonstrated promising diagnostic and assessment capabilities for periodontal wound healing.

The present study offers several strengths that enhance its scientific value and relevance to clinical periodontology. The randomized controlled design minimizes selection bias and enhances the internal validity of the findings. The inclusion of periostin, a novel matricellular protein, as a biomarker for periodontal wound healing provides a molecular insight into healing dynamics beyond traditional clinical measurements. The use of human placental extract, rich in growth-promoting bioactive molecules, presents a promising regenerative approach. Standardized protocols for surgical intervention, GCF sampling, and clinical measurements further add to the methodological robustness. Moreover, the study assessed GCF periostin levels at three timepoints—baseline, 6 weeks, and 3 months—offering a dynamic view of the healing trajectory post-surgery.

Despite these strengths, certain limitations should be acknowledged. The relatively small sample size (n = 16) limits the generalizability and statistical power, particularly for secondary outcomes. The follow-up duration of 3 months, while adequate for preliminary healing assessment, may not capture the full extent of long-term periodontal regeneration. As a single-center study, the findings may not be widely applicable across diverse populations. In addition, the absence of histological analysis restricts definitive conclusions on true regeneration, and the lack of blinding may introduce observer bias. Patient-reported outcomes such as post-operative discomfort and satisfaction were also not assessed, which could provide a more holistic understanding of healing.

Future research should aim to overcome the current limitations by incorporating larger, multicenter trials with extended follow-up periods to assess long-term periodontal stability and regeneration. Including histological evaluation in animal models or biopsy-based human studies would help confirm true periodontal regeneration at a tissue level. Further studies should also evaluate the optimal dosage, delivery method, and frequency of placental extract application for maximizing clinical outcomes. In addition, integrating patient-reported outcomes such as pain perception, quality of life, and aesthetic satisfaction would provide a more comprehensive evaluation of the therapy’s impact. Exploring the synergistic potential of placental extract with other biologics or scaffolds could also offer new regenerative strategies in periodontal therapy.

Conclusions

Among the various biomaterials utilized in surgical periodontal therapy, human placental extract gel emerges as a compelling regenerative agent, distinguished by its remarkable wound-healing properties, anti-infective benefits, and cost-effectiveness. Despite its promise, a definitive marker to precisely delineate the phases of periodontal wound healing remains elusive. Given its pivotal role in core regenerative processes, periostin is a promising biomarker, offering invaluable insights into post-surgical healing dynamics.

Author contributions

MR., RP, and MLP. planned and designed the study. MR., RP, and MLP. performed the experiment. MR., and MIK drafted the manuscript. Additionally, SKB, M.F., and MIK. conducted the editing and final proofreading of the entire document and reviewed the article and contributed to the interpretation. However, all authors critically revised drafts and approved the final work.

Funding

None.

Data availability

The data are available from the corresponding author upon reasonable request.

Declarations

Research involving human participants and/or animals

The present study was designed as a prospective, randomized, controlled clinical trial. The study protocol was reviewed and approved by the institutional review board of Krishnadevaraya College of Dental Science and the hospital ethical committee (REF: Ethical comm/015/2020–21). The study was conducted in full accordance with the declared ethical principles (World Medical Association Declaration of Helsinki, version VI, 2002). All patients completed initial therapy, including oral hygiene instructions, scaling, and root planning.

Consent for publication

Not applicable.

Informed consent

An informed consent was signed by all the participants.

Competing interests

The authors declare no competing interests.