Anti-HLA Antibodies After Bone Regeneration Surgery

Bone regeneration procedures are frequently required before implant-supported prosthetic rehabilitation in patients with insufficient alveolar bone volume. Allogeneic bone graft materials are widely used in oral and maxillofacial surgery because of their favorable osteoconductive properties and biological similarity to human bone. Despite these advantages, concerns have been raised regarding the possible immunological response associated with their use, including the development of anti-human leukocyte antigen (anti-HLA) antibodies.

The presence of anti-HLA antibodies has been well documented in large organ and tissue transplantation procedures. However, recent reports suggest that even smaller regenerative procedures involving allogeneic bone grafts may lead to the development of these antibodies. Such immunological reactions may potentially influence graft integration, healing dynamics, and the overall regenerative outcome.

The aim of this clinical study is to evaluate changes in anti-HLA antibody levels following bone regeneration procedures and to analyze their potential association with bone healing processes. In addition, the study investigates whether adjunctive photobiomodulation using low-level laser therapy (LLLT) may influence the regenerative process.

The study includes twenty generally healthy adult patients who require bone augmentation prior to implant-supported rehabilitation. Patients undergo regenerative procedures involving either xenogeneic or allogeneic bone graft materials. In addition, a subgroup of participants receives postoperative photobiomodulation therapy using a diode laser.

Before surgery, patients undergo clinical and radiological evaluation, including cone-beam computed tomography (CBCT), to assess the anatomical conditions and plan the surgical procedure. Blood samples are collected prior to surgery to determine baseline levels of anti-HLA antibodies.

During the regenerative procedure, bone graft material is placed in the area of the bone defect under local anesthesia using standard surgical techniques. In patients allocated to photobiomodulation therapy, diode laser irradiation is applied in the postoperative period according to the study protocol.

Follow-up evaluation is performed approximately three to six months after the augmentation procedure. At this stage, additional blood samples are collected to assess secondary anti-HLA antibody levels. Radiological examination using CBCT is repeated to evaluate bone regeneration parameters.

During implant placement, bone core biopsies are obtained using a trephine drill to allow histological assessment of regenerated bone tissue. Histological analysis includes evaluation of inflammatory cell infiltrates, trabecular bone formation, and bone morphology.

The results of this study are expected to improve understanding of the immunological response associated with bone grafting procedures and may contribute to the development of more predictable regenerative treatment strategies in implant dentistry.

Inclusion criteria

• Adults aged 18 years or older
• Patients requiring bone augmentation procedures prior to dental implant placement
• Insufficient alveolar bone volume requiring regenerative treatment
• Good general health condition
• Ability and willingness to provide written informed consent

Exclusion criteria

• Systemic diseases affecting bone healing

• Active oral infections or inflammatory conditions at the surgical site
• Use of medications affecting bone metabolism (e.g., bisphosphonates)
• Pregnancy or breastfeeding
• Heavy smoking
• Previous bone grafting procedures in the planned surgical site