This randomized controlled clinical trial evaluated the effectiveness of platelet-rich fibrin (PRF) and a simvastatin/PRF composite combined with a xenogeneic bone graft during alveolar ridge splitting with simultaneous implant placement in patients with horizontal alveolar ridge deficiency. Twenty-one participants were randomly allocated into three groups: a control group receiving xenogeneic bone graft alone, a PRF group receiving xenogeneic bone graft blended with PRF, and a simvastatin/PRF group receiving xenogeneic bone graft blended with a simvastatin/PRF composite. Clinical and radiographic outcomes were assessed to compare horizontal and vertical bone gain, bone density, and keratinized tissue width after treatment.

Horizontal alveolar ridge deficiency frequently complicates implant placement following tooth loss. Alveolar ridge splitting is a well-established technique for horizontal ridge augmentation that allows simultaneous implant placement when sufficient vertical bone height is available. However, the predictability of bone regeneration may be influenced by the grafting material used.

Platelet-rich fibrin (PRF) is an autologous biomaterial rich in platelets, leukocytes, and growth factors that may enhance angiogenesis, soft tissue healing, and bone regeneration. Simvastatin has also demonstrated osteogenic and angiogenic properties through stimulation of bone morphogenetic protein-2 (BMP-2) expression and inhibition of osteoclastic activity. Combining simvastatin with PRF may further improve regenerative outcomes.

This single-center, randomized controlled clinical trial included 21 participants with horizontal alveolar ridge deficiency requiring implant-supported rehabilitation. Participants were randomly allocated into three equal groups (n = 7 per group). Group I underwent alveolar ridge splitting with simultaneous implant placement and augmentation using a xenogeneic bone graft. Group II received a xenogeneic bone graft blended with PRF. Group III received a xenogeneic bone graft blended with a simvastatin/PRF composite.

Clinical and radiographic evaluations were performed to assess horizontal bone gain, vertical bone gain, bone density using cone-beam computed tomography (CBCT), and keratinized tissue width. The study aimed to determine whether the addition of PRF alone or in combination with simvastatin could improve regenerative outcomes compared with conventional xenogeneic bone grafting.

Inclusion Criteria:

Horizontal alveolar ridge width of 3-5 mm. Vertical alveolar bone height of ≥11 mm. Edentulous site located in the mandibular anterior region. Absence of buccal bone undercuts. Male or female participants aged 18-50 years. Good general health and medically fit to undergo oral surgical procedures. Absence of periapical pathology at the intended implant site. Adequate crown height space to achieve a favorable crown-to-implant ratio. Willingness and ability to attend all scheduled follow-up visits. Provision of written informed consent.

Exclusion Criteria:

Uncontrolled systemic diseases (e.g., uncontrolled diabetes mellitus), active infection, bleeding disorders, or current anticoagulant therapy.

Severe systemic diseases (e.g., uncontrolled hypertension or severe cardiovascular disease).

Severe alveolar bone deficiencies not suitable for ridge splitting. Pregnancy or breastfeeding. Inability to comply with postoperative instructions or follow-up visits. Known allergy or hypersensitivity to simvastatin or study materials. Individuals from vulnerable populations unable to provide valid informed consent.

Bruxism or other parafunctional oral habits.

There is no plan to share individual participant data (IPD) with other researchers. De-identified participant data will not be made publicly available. Study results will be disseminated through peer-reviewed publications and conference presentations.

Not applicable. The surgeon and participants were aware of the assigned intervention because of the nature of the surgical procedures and biomaterials used.