This prospective controlled clinical pilot study will compare the effectiveness of two different grafting strategies for horizontal bone regeneration in healed post-extraction sites with buccal bone deficiency, using a collagenated porcine cortical bone lamina as a barrier membrane.

A total of 21 patients requiring implant-supported rehabilitation associated with bone regeneration will be enrolled, for a total of 40 implants. In the test group, bone defects will be grafted using a collagenated cortico-cancellous sticky xenograft, while in the control group a mixture of hydroxyapatite-based xenograft and autologous bone in a 1:1 ratio will be used. In both groups, a semi-rigid collagenated cortical bone lamina will be applied and stabilized to contain the graft material and maintain space for regeneration.

The primary objective of the study will be to evaluate volumetric bone changes over time using cone-beam computed tomography imaging, comparing baseline and follow-up scans. Secondary outcomes will include linear measurements of bone gain at different levels around the implant site.

The study will investigate whether collagenated xenografts alone can provide comparable clinical and radiographic outcomes to combined grafting approaches including autologous bone, while potentially reducing patient morbidity associated with bone harvesting.

Severe alveolar ridge resorption following tooth extraction may result in insufficient bone width and compromised anatomical conditions for implant placement, particularly in sites with buccal cortical plate deficiency. In such cases, guided bone regeneration (GBR) procedures will be required to restore adequate bone volume and allow for prosthetically driven implant rehabilitation.

A wide range of grafting materials will be used in clinical practice for bone regeneration, including autologous bone, allogeneic and xenogeneic biomaterials, as well as synthetic substitutes. Among these, xenogeneic collagenated grafts will be increasingly adopted due to their favorable biological properties, including clot stabilization, facilitation of early cellular infiltration, and promotion of angiogenesis. However, their relatively rapid remodeling rate may influence the final volumetric stability of the regenerated bone.

Barrier membranes will play a crucial role in GBR procedures by preventing soft tissue invasion and maintaining space for bone regeneration. Recently, collagenated porcine cortical bone laminae will be introduced as semi-rigid membranes combining the advantages of mechanical stability and biocompatibility. When properly stabilized, these devices will act as containment structures for graft materials, potentially improving regenerative outcomes.

The present study will be designed as a prospective controlled clinical trial to evaluate the effectiveness of two different grafting strategies for horizontal bone regeneration in healed post-extraction sites presenting buccal bone deficiency. Patients requiring implant-supported rehabilitation associated with bone augmentation procedures will be consecutively enrolled and allocated to one of two treatment groups.

In the test group, bone defects will be grafted using a collagenated cortico-cancellous sticky xenograft. In the control group, a mixture of hydroxyapatite-based xenograft and autologous bone in a 1:1 ratio will be used. In both groups, a collagenated porcine cortical bone lamina will be applied as a barrier membrane and stabilized using fixation pins to ensure space maintenance and graft containment.

All surgical procedures will be performed under local anesthesia by an experienced operator following standardized clinical protocols. After implant placement and grafting, primary wound closure will be achieved, and patients will receive appropriate postoperative care, including antibiotics and analgesics as indicated. Sutures will be removed after a healing period of approximately 10-14 days.

Radiographic evaluation will be performed using cone-beam computed tomography (CBCT) scans acquired before surgery (baseline) and at follow-up. Digital datasets will be analyzed using dedicated three-dimensional software to assess volumetric changes in the regenerated bone. Linear measurements will also be obtained at predefined reference levels around the implant site, including the implant neck, 3 mm apically, and at the implant apex.

Implant-supported prosthetic rehabilitation will be completed after a healing period of approximately six months, following confirmation of implant osseointegration.

The primary outcome of the study will be the volumetric change of regenerated bone over time. Secondary outcomes will include linear bone gain at different levels and the influence of clinical and anatomical variables such as patient age, sex, and implant site localization.

Statistical analysis will be performed at the implant level. Continuous variables will be assessed for normality and compared between groups using appropriate parametric or non-parametric tests. Multivariable regression models will be applied to evaluate the association between treatment group and outcomes while adjusting for potential confounding variables.

This study will aim to determine whether collagenated xenografts alone will provide comparable regenerative outcomes to combined approaches including autologous bone, potentially reducing surgical invasiveness and donor-site morbidity while maintaining adequate bone volume for implant-supported rehabilitation.

Inclusion Criteria:

• Healed type II post-extraction sockets according to the Elian classification
• Age between 18 and 80 years
• Good periodontal control, defined as treated periodontitis with plaque index <25% and bleeding on probing <25%
• ASA I or ASA II systemic status
• Ability and willingness to provide written informed consent
• Ability and willingness to attend scheduled follow-up visits

Exclusion Criteria:

• Smoking more than 10 cigarettes per day
• Active oral infections
• Mucosal diseases, including erosive lichen planus
• History of radiotherapy in the head and neck region
• Systemic diseases affecting bone metabolism or contraindicating oral surgery
• Non-compliance or inability to complete follow-up
• Extraction sockets with intact bone walls

De-identified individual participant data underlying the results reported in this study will be made available upon reasonable request to the corresponding author, following publication of the study results. Data sharing will be subject to institutional policies and applicable regulations to ensure patient confidentiality and data protection.

Data will be available beginning 6 months following publication of the primary results and will remain available for up to 5 years.

Access to de-identified individual participant data and supporting documents will be granted to researchers who provide a methodologically sound research proposal. Requests will be reviewed by the study investigators. Data will be shared after approval of a data access agreement and in compliance with institutional policies and applicable data protection regulations. Data will be made available upon reasonable request to the corresponding author.