Influence of adding a pericardium membrane to the bioactive shield technique in vestibular socket therapy for immediate implant placement in Type II alveolar sockets: a randomized clinical trial

Abstract

This investigation aimed to compare the efficacy of a slowly resorbable cortical laminar bone membrane (CLBM), used either in isolation or in combination with a pericardium membrane, alongside an enriched bone graft. The treatment was to ascertain improvements in buccal plate thickness, buccal plate height, and soft-tissue thickness after immediate dental implant placement into Type II alveolar sockets managed with VST. Thirty participants with type II alveolar sockets were randomly assigned to two experimental cohorts. They received immediate implants with CLBM after sticky bone application in group A. In group B, they received coverage with a pericardium membrane after application of CLBM and sticky bone. All participants underwent periodic clinical and radiographic assessments over a six-month follow-up duration. At 6 months, Group B showed a statistically significant augmentation in buccal bone thickness at the coronal (p-value = 0.04) and midpoint (p-value = 0.02). Furthermore, Group A manifested a highly significant decrease in buccal plate height (p-value = 0.002). Soft tissue thickness shows a non-significant reduction in soft tissue values in group A(p-value = 0.36) and a significant increase in group B (p- value = < 0.001). The integration of a pericardial membrane with a cortical lamellar bone membrane and an autologous fibrin-rich bone graft demonstrated a synergistic effect, culminating in superior alveolar bone preservation. The study was registered at ClinicalTrials.gov NCT06867848.

Supplementary Information

The online version contains supplementary material available at https://doi.org/10.1007/s44445-026-00219-y.

Introduction

An essential prerequisite for prompt implant placement is the existence of an undamaged facial bone wall at the extraction site. However, the maxillary labial cortical plate is frequently thin and susceptible to fenestration or dehiscence. Implant insertion right away in locations with facial bone abnormalities may increase the likelihood of implant failure and compromise aesthetic results by predisposing to soft-tissue recession (Abdel-Raheim & Al-Fakharany 2019; Botermans et al. 2021). A defect classification proposed by Liñares et al. 2023 in earlier literature outlined problems arising from vertical and horizontal soft- and hard-tissue loss. The complete integrity of the labial bone plate and the surrounding soft tissues is included in Type 1. Type 2: Soft tissue is present, but there is an underlying dehiscence in the bone, showing that the labial bone plate may be completely or partially absent. Type 3: A midfacial recession defect where the labial bone plate and soft tissues are both lost (Liñares et al. 2023).

In the field of implantology, Elaskary et al. 2020 developed the Vestibular Socket Therapy (VST) procedure, providing a new method for rapid implant insertion in compromised extraction sites, especially Type 3 sockets lacking a labial bone plate. VST is a minimally invasive technique that allows for immediate implant insertion, even in sockets with weak facial bone support, and is intended to produce predictable cosmetic results. A significant advancement in regenerative dentistry has been made with the introduction of the Cortical Laminar Bone Membrane (CLBM), a product made from xenogeneic bone tissue. CLBM’s surface actively promotes osteogenic cell adhesion. This makes it easier for mesenchymal stem cells to migrate and eventually differentiate into osteoblasts (Tumedei et al. 2022; Nehal et al. 2024).

The pericardium is a practical membrane choice for Guided Tissue Regeneration. Structurally, the pericardium is a robust biological tissue characterized by dense, layered collagen, primarily Type I and Type III, interwoven with elastin fibers. The mechanical integrity of this tissue is directly attributable to the high concentration and specific orientation of these collagen types (Jaworska-Wilczynska et al. 2016; and Rodriguez & Tan 2017).

The synergistic healing properties of CLBMs and pericardium provide biological justification for their combined usage. While the cortical laminar bone offers an osteoconductive scaffold and crucial structural integrity (Tumedei et al. 2022; Pinto et al. 2025), the pericardium acts as a collagen-rich, biocompatible barrier. In addition to stabilizing the graft, this later membrane promotes directed tissue regeneration by creating an environment that encourages cell migration and proliferation (Jaworska-Wilczynska et al. 2016; Dasuki et al. 2025). Furthermore, during the crucial early healing phase, the pericardium’s moderate resorption rate provides protective shielding for the underlying bone membrane, maximizing outcomes for both hard and soft tissues (Rojas et al. 2021).

Although VST has shown favorable outcomes in compromised sockets, evidence regarding whether an additional pericardium membrane provides further clinical benefit over CLBM alone remains limited.

Specifically, the present study compares the use of a slowly resorbable Cortical Laminar Bone Membrane with a pericardium membrane, with CLBM alone to improve hard- or soft-tissue outcomes.

Material and method

A randomized clinical trial was conducted from March 2025 to October 2025. The study was registered on ClinicalTrials.gov on 5 March 2025 under the running title; the identifier is NCT06867848.

Sample size and patient grouping

Based on earlier findings by Eltoukhy et al. 2025; the sample size was determined using the G*Power statistical analysis program (Version 3.1.9.4) for the difference between two independent means, with an actual power (1-β error) of 0.8 (80%) and a primary risk of error (α = 0.05). Measurements of buccal bone thickness as the primary outcome and its increase (1.00 ± 0.60) and (0.54 ± 0.21) following six months of vestibular socket therapy (VST) were used to decide the sample size. The overall sample comprised an estimated 28 patients. The total sample size obtained for the examination of buccal bone alterations will be 30 patients (evenly and randomly assigned into 15 patients in each group), accounting for a 10% probability of dropouts during the follow-up period (about 2 patients), which is adequate to identify the Cohen’s d = 0.976 effect size.

Patient grouping and allocation

patient allocation

The study adhered to CONSORT 2010; about 100 patients were assessed by surgeons in the outpatient clinic of the Faculty of Dental Medicine for Girls at Al-Azhar University for teeth in the esthetic zone that should be extracted, with a type II socket created and immediately replaced with an implant. Patients were assessed according to the research’s inclusion and exclusion criteria. Only thirty patients were included in this study after seventy were removed. A random number generator (Random.org) was used to randomly assign study participants to experimental groups, guaranteeing a 1:1 allocation ratio. The randomization sequence was carefully developed by the statistician. These randomized assignments were then distributed to all patient locations and safely placed in opaque, sealed envelopes with sequential numbers. This methodical technique made the objective assignment easier. This systematic approach facilitated unbiased assignment of patients to either group A or B, with strict adherence to the predetermined randomization schedule (Fig. 1).

Fig. 1.

Flow diagram for patients’ selection and allocation

Blindness

Outcome assessors, participants, and the statistician were blinded to treatment allocation. Owing to the nature of the intervention, the operating surgeon could not be blinded. At the same time, the lead investigator prepared the subjects for surgical implantation. On the day of the procedure, group allocations were shown when the corresponding envelopes were opened. Treatment allocation concealment was essential, as it ensured that staff members responsible for participant enrollment were unaware of the specific therapy each participant would receive. To ensure that participant group allocations were completely independent of their final therapy, this methodological rigor was crucial in reducing selection bias. After completing all follow-up intervals, the patients in this study were categorized as follows.

Patient grouping

Thirty participants were distributed into two groups as follows: Group A (n = 15): Immediate implant placement with CLBM following sticky bone application. Group B (n = 15): Immediate implant placement with CLBM and sticky bone, followed by coverage with a pericardium membrane.

Inclusion criteria

Participants eligible for this study were individuals aged 20 to 50 years, in good systemic health, and requiring the extraction of one upper esthetic zone tooth that cannot be restored. Although these patients showed a Type II socket (Elian et al. 2007; Eltoukhy et al. 2025), characterized by a deficient facial bone plate, they had adequate bone volume in the apical and palatal regions, which was crucial for achieving proper implant positioning and initial stability.

Exclusion criteria

The patient with Active localized sepsis associated with a non-restorable tooth, individuals with significant nicotine dependence, specifically those consuming greater than 10 cigarettes daily, pregnant individuals, and individuals with a history of antineoplastic pharmacological or radiation therapy within the preceding 12 months (Abdelaziz et al. 2020) were excluded from this study.

Surgical procedures

Before the commencement of the study, all participants were fully briefed on the research procedures and provided their written informed consent.

All patients underwent a comprehensive medical evaluation, including dental history recording, assessment of general and oral health status, and preoperative CBCT scanning to evaluate the socket type II, determine appropriate implant dimensions, and define the implant site.

Two examiners assessed radiographic parameters on CBCT twice (the intraclass correlation coefficient was used to assess inter-examiner reliability, showing high agreement between the examiners) preoperatively to determine precise bone quality, the morphology of the Class II socket, and the requisite implant diameters. Post-operatively, buccal plate dimensions, specifically their height and thickness, were assessed at two distinct locations: the most coronal aspect and a midpoint situated 5 mm apically from the initial coronal measurement. A third examiner assessed the clinical parameters. All examiners involved were blinded to the study groups and the study protocol. A single operator carried out all surgical interventions.

A sticky bone preparation

Cerabone xenograft granules (0.5–1 mm) were combined with injectable platelet-rich fibrin (I-PRF) to create a sticky bone. Five to ten milliliters of the patient’s venous blood were centrifuged at 800 rpm for 3 min in non-coated Vacutainer tubes to produce I-PRF. To create the sticky bone, the supernatant I-PRF layer was separated, mixed with the xenograft, and left for five to ten minutes to polymerize (Albash et al. 2025).

Flap design

A horizontal vestibular incision, placed 3 to 4 mm apical to the mucogingival junction and extending 5 to 10 mm mesiodistally, was used to begin VST access to the operative site. A sub-mucoperiosteal tunnel was then carefully created, starting from the original vestibular incision and moving coronally along the affected tooth’s facial aspect. A painful extraction of a tooth that cannot be restored using a peristome following flap reflection (Eltoukhy et al. 2025).

Extraction

Following tooth extraction, the dental socket was thoroughly debrided and degranulated via deep curettage to remove all residual soft tissue, followed by 30 s of irrigation with sterile saline.

Implant placement

A two-piece, tapered, screw-type titanium implant (NeoBiotechTM implant, Gangwon-do, South Korea), with dimensions ranging from 13 to 16 mm in length and 3.5 to 4 mm in diameter, was selected. The osteotomy preparation involved a continuous drilling sequence using successive drills. Meticulous attention was directed towards positioning the implant palatally, ensuring that the horizontal labial jumping-gap distance did not exceed the critical threshold of 2 mm.

Membranes and sticky bone applications

In both groups, CLBM (Maxxus, USA; Allograft Laminar Bone, 1.5 × 2.0 cm) was carefully advanced through the previously established tunnel originating from the vestibular incision. Positioned along the facial aspect without the need for bone tacks, as it was confined to the tunnel prepared through VST. Prevention of membrane exposure during flap closure and suturing was achieved by seating the membrane 1 mm subgingivally. The existing jumping gap was later augmented with the prepared sticky bone graft material. To improve graft adaptation and minimize hematoma formation and dead space, gentle pressure was applied to the inserted membrane using moist gauze for 10 min.

For Group B, an additional pericardium membrane (Maxxus, USA, Pericardium 1.5*2.0 cm) was placed over the CLBM, serving as a soft tissue graft that provides complete coverage (Fig. 2).

Fig. 2.

A photograph showing the pericardium membrane insertion through the vestibular incision

Suturing

Primary closure of the flap was achieved using tension-free absorbable Vicryl sutures.

Treatment outcomes

Buccal bone width is the primary endpoint, while changes in buccal bone height and soft tissue thickness are secondary endpoints of this study. At baseline (T0) and 6 months (T1), all patients underwent radiographic evaluations of buccal plate thickness, changes in buccal plate height, and soft-tissue thickness.

Radiographic analysis

The CBCT (Scanora 3D Soredex, Helsinki, Finland) was used to obtain radiographic data for every patient. A Complementary Metal-Oxide-Semiconductor (CMOS) flat panel detector was installed in this system, providing an isotropic voxel size of 133 μm. The X-ray tube parameters for scanning were 16 mA, 85 kVp, and 0.5 mm focal spot size. Scanning durations ranged from 10 to 26 s, depending on the selected Field of View (FOV), utilizing pulsed exposure to achieve an effective exposure time of 3 to 6 s. Available FOV options included 7 cm (height) × 10 cm (width) × 10 cm (depth) or 13 cm (height) × 14.5 cm (width) × 14.5 cm (depth). Precise FOV adjustment and centralization of the region of interest within the scanning field were facilitated by a three-laser light beam guidance system.

OnDemand 3D imports the T0 and T1 DICOM (Digital Imaging and Communications in Medicine) files. The “fusion module” loads both files simultaneously. In the axial, coronal, and sagittal slices, T1 is shifted as near to T0 as feasible after choosing “manual registration.” Clicking “auto registration” automatically places T1 on top of the T0 image. After that, T1 with the changed orientation is exported by choosing “reslicing” and exporting just the “secondary image.” T1 has a new orientation that matches T0 and shares the same coordinates after completing all the preceding processes. It is possible to visualize both images. The primary and secondary photos were given different color codes for easy identification (Fig. 3).

Fig. 3.

A CBCT radiograph showing the fusion between the preoperative and 6-month postoperative images

Measurements were initially conducted on the primary image. Subsequently, to obtain the secondary image for comparative analysis, the original image was removed, keeping only the primary image’s measurements. Standardization was achieved by measuring the secondary image with the same orientation and sectioning plane as the original.

Buccal plate thickness

BBT was quantitatively assessed in the sagittal dimension. This assessment utilized two distinct measurement planes, positioned parallel to both the coronal and midpoint aspects (5 mm from the coronal point) of the dental implant (Fig. 4A-B).

Fig. 4.

(A and B). A radiograph showing pre-operative and six months post-operative buccal plate thickness, coronal, and 5 mm away from the coronal point, respectively

Buccal plate height

Sagittal planes were used to properly define the borders of the implants. The first bone-to-implant contact at the buccal aspect was measured linearly from a standard reference point at the implant neck (Fig. 5A-B).

Fig. 5.

Measuring marginal bone height loss 6 months postoperatively (A) Sagittal view (B) Coronal view

Soft tissue thickness

During CBCT acquisition, patients maintained a standing posture, with their chins and heads meticulously stabilized to minimize motion artifacts. Furthermore, participants were instructed to keep their tongues positioned low within the oral cavity. To facilitate control imaging and serve as a gingival photographic developer, a periodontal plug (Pulpdent Corp, Brookline, MA) was applied to the gingival surface before CBCT scanning. Soft-tissue thickness was subsequently quantified from cross-sectional CBCT images. The length between the alveolar crest and the gingival surface determined the thickness of the gingiva. A vertical line demarcates the outer surface of the alveolar bone, then a perpendicular line from this line to the gingival edge to decide the thickness 2 mm below the free gingiva and 5 mm apical to the coronal one.

Statistical analysis

SPSS (Statistical Package for the Social Sciences) version 26 was used to evaluate numerical data. For quantitative variables, the mean and standard deviation (SD) were determined. Statistical significance was defined as P values < 0.05 at a confidence level of 95%. By examining the data distribution and applying the Shapiro-Wilk and Kolmogorov-Smirnov tests, the normality of the data was investigated. In both groups, the values were distributed regularly. An independent sample t-test was used for intergroup comparison, while a paired t-test was used for intragroup comparison.

Results

Buccal bone thickness

In group A, there was a non-significant reduction in buccal bone thickness after the intervention procedure (0.72 ± 0.29) in the coronal point at (P = 0.2), while there was a non-significant increase in buccal bone thickness values (0.58 ± 0.27) after the intervention procedure in the midpoint at (P = 0.496) (Table 1).

Table 1.

Represents intragroup and intergroup comparisons of buccal bone thickness values at coronal and midpoint parts within and between the two different studied groups, measured in mm

Groups	Intervention procedure	Buccal bone thickness (Mean±SD)
		Coronal		Midpoint
Group A	Before	1.104±0.57		0.49±0.11
	After	0.72±0.29		0.58±0.27
	95% confidence interval	-0.31	1.07	-0.44	0.26
	Intragroup P value	0.2NS		0.496NS
Group B	Before	0.78±0.23		0.41±0.11
	After	1.19±0.54		0.82±0.26
	95% confidence interval	0.35	1.17	0.53	1.36
	Intragroup P value	0.04S		0.02S
95% confidence interval		Before	-1.19	Before	-0.51
			1.85		0.68
		After	0.44	After	-1.1
			1.37		0.62
Effect size Cohen´s d		Before	0.75	Before	0.73
		After	1.08	After	0.91
Intergroup P value		Before	0.62NS	Before	0.75NS
		After	0.026S	After	0.53NS

S: significant (P≤ 0.05), HS: highly significant (P<0.001), NS: non-significant (P>0.05)

In group B, there was a significant increase in buccal bone thickness values after the intervention procedure in the coronal point (1.19 ± 0.54) and midpoint (0.82 ± 0.26) at (P = 0.035) and (P = 0.02), respectively (Table 1).

Comparing the two groups revealed no significant differences in buccal bone thickness at baseline for either coronal or midpoint measurements (P = 0.62 and P = 0.75, respectively). Post-intervention, a significant difference was seen at the coronal level (P = 0.026), with Group B recording the highest value (1.19 ± 0.54 mm). At the midpoint, no significant difference was detected (P = 0.53), although Group B showed the highest mean value (0.82 ± 0.26 mm) (Table 1).

Change of buccal plate height

In Group A, a statistically significant decrease in buccal plate height was observed over a 6-month follow-up period, with values reducing from 10.89 ± 0.54 to 9.05 ± 0.32. Conversely, Group B experienced a non-significant reduction in buccal plate height, with measurements changing from 11.45 ± 0.55 to 10.41 ± 0.47 during the same 6-month period. Upon comparing the two groups, no significant difference was found at baseline (P = 0.145). However, a significant difference emerged after 6 months (P = 0.009), with Group A exhibiting the lowest buccal plate height (9.05 ± 0.32). Furthermore, the percentage of buccal bone reduction was significantly greater in Group A (16.76 ± 4.81) compared to Group B (9.09 ± 1.56), with a P-value of 0.021. (Table 2).

Table 2.

Represents intragroup and intergroup comparisons of changes in buccal plate height values within and between the two different studied groups, measured in mm

Groups	Buccal bone height (Mean ± SD)		Intragroup P value	Effect size Cohen´s d	Percentage of reduction (%)	95% confidence interval of the mean difference
	Baseline	After 6 months				Lower bound	Upper bound
Group A	10.89 ± 0.54	9.05 ± 0.32	0.002 S	4.15	16.76 ± 4.81	1.13	2.56
Group B	11.45 ± 0.55	10.41 ± 0.47	0.056NS	2.03	9.09 ± 1.56	-0.79	1.29
95% CI	-1.35 0.24	-1.9 -0.77	------------		0.021 S
Intergroup P value	0.145NS	0.009 S

S: significant (P ≤ 0.05), HS: highly significant (P < 0.001), NS: non-significant (P > 0.05)

Soft tissue

Within group A, there was a non-significant reduction in soft tissue values after 6 months (1.24 ± 0.84) at (P = 0.357), while there was high significant increase in soft tissue values after 6 months in group B (2.33 ± 0.48) at (P < 0.001). Comparing two groups, there was a non-significant difference in soft tissue values at baseline (1.39 ± 0.95, 1.36 ± 0.58), respectively, at (P = 0.938). After 6 months, there was a significant difference in soft-tissue values between the two groups (P = 0.025). The highest gain was recorded in group B with a mean = (2.33 ± 0.48). (Table 3).

Table 3.

Represents intragroup and intergroup comparisons of soft tissue values within and between the two different studied groups, measured in mm

Intervals	Soft tissue (Mean ±SD)		Mean difference	95% CI		Effect size Cohen´s d	P value
	Group A	Group B		Lower bound	Upper bound
Baseline	1.39±0.95	1.36±0.58	0.037	-0.98	1.05	0.04	0.938 NS
6 months	1.24±0.84	2.33±0.48	-1.08	-1.99	-0.17	1.59	0.025 S
95% CI	-0.23	-1.1
	0.54	-0.84
P value	0.36 NS	<0.001 HS

S: significant (P ≤ 0.05), HS: highly significant (P < 0.001), NS: non-significant (P > 0.05)

Discussion

Significant dimensional changes of the alveolar ridge are regularly reported in experimental and clinical studies after tooth extraction. In particular, the buccal plate exhibits a more noticeable reduction in bone resorption patterns than the lingual or palatal plate. Additionally, decreases in the horizontal dimension are typically more significant and clinically significant than changes in the vertical dimension (Naldini et al. 2022). The degradation of bone tissue presents considerable challenges to the successful implementation of functional and aesthetically pleasing dental restorations.

The present study compares the use of a slowly resorbable Cortical Laminar Bone Membrane, with or without a pericardium membrane, in conjunction with an enriched bone graft, to assess improvements in buccal plate thickness, buccal plate height, and soft-tissue thickness, after immediate placement of a dental implant in a type II socket with VST after 6 months. In an undisturbed extraction socket, early osteoid formation begins at 7 days, followed by mineralization at 21 days, which reaches an advanced stage by 6 weeks. Consequently, it is reasonable to anticipate spontaneous bone regeneration around immediate implants, provided the blood clot remains protected and covered. Therefore, a six-month follow-up is considered appropriate for evaluating early regenerative outcomes, although it is insufficient to assess long-term stability. This follow-up duration also aligns with many published studies in scientific literature that use similar follow-up periods to evaluate the initial efficacy of regenerative interventions (Singh et al. 2021; Elaskary et al. 2023; and Eltoukhy et al. 2025).

Following the intervention, the radiographic results indicate that Group A exhibited a non-statistically significant increase in buccal bone thickness at the midpoint. In contrast, Group B showed a statistically significant increase in buccal bone width at both the coronal point and midpoint post-intervention. This agrees with Elaskary et al. (2024, 2022, 2020), who reported that VST is instrumental in preserving buccal bone by obviating the need for flap elevation. This procedure does not carry the risk of inducing trauma and inflammation to the periosteum and its associated blood supply. Their findings indicated a significant increase in bone thickness at both the crestal and middle thirds.

Pinto et al. (2025) reported that CLBM exhibits a dual biological capacity, promoting both osteoconduction and osteoinduction. Their osteoconductive nature stems from a porous architecture that supports migration and adhesion of osteoprogenitor cells. Concurrently, osteoinductive properties are attributed to the gradual release of endogenous bone morphogenetic proteins (BMP-2, BMP-7, BMP-9) preserved within the mineralized matrix during resorption.

Furthermore, Sticky bone offers several advantages in regenerative procedures. Its inherent moldability facilitates precise adaptation to diverse morphologies of osseous defects. Furthermore, the material effectively mitigates both micro- and macro-movements of the grafted bone, thereby preserving the augmented volume throughout the healing phase and consequently reducing the necessity for block bone grafts and titanium mesh. The fibrin network within the sticky bone entraps platelets and leukocytes, promoting the localized release of growth factors that accelerate both bone regeneration and soft tissue healing (Dong-Seok Sohn et al. 2015).

A statistically significant disparity in buccal bone thickness was seen at both the coronal and midpoint assessments when comparing Groups A and B. A significant increase in group B compared to group A may occur due to the BPM application. BPM offers several advantages over other bioresorbable membranes, including high biocompatibility and its efficacy in promoting periodontal tissue regeneration by establishing a stable microenvironment conducive to cellular activity. According to a study by Dasuki et al. 2025; BPM promotes the growth and differentiation of osteoblasts and periodontal ligament fibroblasts, thereby stimulating tissue regeneration. It accomplishes this by creating a naturally favorable milieu that promotes the migration and proliferation of host cells. The intrinsic advantages of BPM, including their better consistency and acellular composition, are largely responsible for these regeneration powers with a minimum thickness of around half a millimeter. Because BPM resembles an extracellular matrix that offers mechanical support for cell adhesion, it can function as a framework. Additionally, BPM is the best material to use as a barrier in direct bone regeneration or socket preservation.

Maintaining peri-implant tissue stability and attaining desirable aesthetic results in the front maxilla are thought to depend on preservation of the facial bone wall. Consequently, the increased buccal bone thickness attained with the simultaneous application of the pericardium membrane may enhance the long-term retention of the ridge contour and lower the danger of soft tissue recession. Preservation of the buccal plate bone enhances long-term implant survival. This view aligns with earlier studies that highlight the importance of preserving buccal bone volume around implants placed immediately (Botermans et al. 2021; Elaskary et al. 2024).

Following the intervention procedure, Group A showed a statistically significant decrease in buccal plate height. Conversely, Group B experienced a non-significant reduction during the same 6-month period. However, a significant difference emerged after 6 months. The VST necessitated primary closure, which precluded complete primary wound closure over the post-implantation alveolar socket. This accelerated time of its resolution is the predominant complication associated with CLBM application (Pinto et al. 2025). In Group B, the pericardium membrane housing of CLBM prevents this action.

Rojas et al. 2021 reported that the clinical utility of BPM is significantly enhanced by its innovative decellularization process, which preserves its collagen structure, and by a subsequent crosslinking treatment. This results in a prolonged reabsorption period from 3 to 6 months. This extended resorption time retains the crucial advantage of complete biological integration and eventual resorption (Rojas et al. 2021). This attribute is particularly relevant to the findings in Group B, where the BPM application effectively ensures complete coverage of CLBM, thereby preventing exposure and subsequent premature bone resorption, which is vital for successful bone regeneration.

From a clinical perspective, minimizing buccal plate height reduction is important because preservation of the facial bone supports the peri-implant soft tissues and helps maintain the natural gingival architecture. Consequently, the improved preservation observed in Group B may enhance the long-term esthetic stability of immediately placed implants.

Initial assessment revealed no statistically significant differences in soft-tissue parameters between the two cohorts at baseline. However, at the six-month post-intervention evaluation, there was a significant difference in soft-tissue thickness. This observation aligns with the results of Athar et al. 2014; who concluded that periodontal ligament fibroblasts cultivated on bovine pericardium membranes adopted a flattened, spindle-shaped morphology, indicative of robust cellular viability, in contrast to their more rounded counterparts. Furthermore, a pronounced proliferative pattern was observed, characterized by cellular adhesion to the membrane fibers via lamellipodia and filopodia, along with a discernible alignment of cells along the fibrous architecture. The fibroblasts were observed not only to proliferate superficially but also to migrate into the deeper strata of the membrane, traversing the interstitial spaces within the fibrous network.

Clinically, the increased soft-tissue thickness observed in Group B may provide greater resistance to peri-implant mucosal recession and enhance the esthetic integration of implant-supported restorations, particularly in the anterior esthetic zone. These findings agree with earlier studies demonstrating the favorable biological behavior of bovine pericardium membranes in supporting soft tissue healing and regeneration (Athar et al. 2014; Dasuki et al. 2025).

Conclusion

With the limitations of this study, both treatment modalities act as a bioactive shield for immediate dental implants in socket type II. The integration of a pericardium membrane with CLBM and an autologous fibrin-rich bone graft appeared to enhance hard- and soft-tissue preservation compared with CLBM alone.

Limitation

The limitations of the present study include its relatively short six-month follow-up period, its relatively small sample size, and its lack of aesthetic indices. Although this duration and sample size are sufficient to evaluate early healing and regenerative outcomes, they make it impossible to assess the long-term stability of the regenerated hard and soft tissues. It is advised that further research with a longer follow-up period and a larger sample size verify the long-term stability of these findings.

Supplementary Information

Below is the link to the electronic supplementary material.

Author contributions

1. HMR: Conceptualization, Methodology, Investigation, Radiographic analysis, Writing -Original draft, Writing - Review & Editing. 2. LMA : Methodology, Software, Formal analysis, Data curation, Writing -original draft, Writing - Review & Editing. 3. HHA, HAMA: Methodology, Validation, Histopathological analysis, Writing - Original draft, Project administration. 4. DAH, JAA: Conceptualization, Methodology, Radiographic analysis, Resources, Writing - Original draft, Project administration, Writing - Review & Editing.

Data availability

All data generated or analyzed during this study are included in this published article.

Declarations

Ethical approval

At the outpatient clinics of Al-Azhar University's Faculty of Dental Medicine for Girls, a randomized clinical trial was carried out from March 2025 to October 2025. The Research Ethical Committee of the Faculty of Dental Medicine for Girls, Al-Azhar University, which is approved and functions in accordance with ICH GCP guidelines as well as applicable local and institutional regulations and guidelines that govern IRB operation, provided comprehensive ethical approval for all methodologies used. Code of Appointment: [REC-SU-25-03b].

Consent for publication

Not applicable.

Statement from the author

The manuscript’s corresponding author, entitled (Influence of Adding Pericardium Membrane on the Bioactive Shield Technique in Vestibular Socket Therapy for Immediate Implant Placement in Type II alveolar Sockets. Randomized clinical trial), proves that every co-author has verified the correctness of the authorship and conflict of interest disclosures provided in this manuscript.

Competing interest

The authors declare no competing interests.