Graft materials and regenerative strategies for secondary alveolar bone grafting: a scoping review of randomized trials

Secondary alveolar bone grafting (SABG) remains a cornerstone procedure in the comprehensive management of patients with cleft lip and palate. It aims to restore maxillary arch continuity, facilitate tooth eruption and orthodontic movement, close oronasal fistulae, and provide structural support for nasal base and alveolar stability. Although autogenous iliac crest cancellous bone has long been considered the gold standard, concerns regarding donor-site morbidity, graft resorption, variable volumetric stability, and surgical burden have stimulated the development of alternative graft materials and regenerative adjuncts. Over the past decade, a wide range of graft materials and biologically active strategies have been investigated in randomized controlled trials (RCTs), including demineralized bone matrix, xenografts, allografts, bone marrow aspirate concentrate, platelet-rich plasma (PRP), platelet-rich fibrin (PRF), mineralized plasmatic matrix (MPM), stem-cell–based constructs, and other tissue-engineered approaches. However, the literature remains heterogeneous in terms of study design, outcome measures (e.g., volumetric analysis, density assessment, bone height scores), follow-up duration, and methodological quality. To date, no comprehensive scoping review has systematically mapped and synthesized evidence exclusively from randomized trials in this domain. The purpose of this scoping review is to systematically identify, map, and categorize all published randomized controlled trials evaluating graft materials and regenerative strategies used in secondary alveolar bone grafting. This review will follow the methodological framework proposed by Arksey and O’Malley, enhanced by Levac et al., and will be reported according to the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) guidelines. Specifically, this review aims to: Identify and classify the types of graft materials and biologic/regenerative adjuncts evaluated in randomized trials for SABG. Map reported clinical and radiographic outcome measures, including volumetric bone fill, bone density, graft resorption rates, periodontal outcomes, fistula closure, and complications. Describe methodological characteristics of included trials (sample size, age at grafting, dentition stage, follow-up duration, imaging modality, randomization method). Identify gaps in the current randomized evidence base, including underexplored biomaterials, lack of standardized outcome reporting, insufficient long-term follow-up, and methodological limitations. The expected outcome of this project is a structured evidence map that clarifies the current landscape of randomized research in secondary alveolar bone grafting. The findings will inform clinicians, researchers, and guideline developers regarding existing evidence, methodological trends, and areas requiring further high-quality investigation. Ultimately, this review aims to support evidence-based decision-making and guide future trial design in regenerative strategies for alveolar cleft reconstruction.