Osteoblastic Differentiation and Proliferation of Human Mesenchymal Stem Cells or Osteoblast-like Cells on Bone Scaffolds in Oral and Periodontal Surgery: A Systematic Review of <i>In Vitro</i> Studies

Aim: This systematic review critically evaluates in vitro studies on the osteoblastic behavior of human mesenchymal stem cells (hMSCs) and human osteoblast-like cells on three-dimensional (3D) bone scaffold materials. The review identifies key osteogenic proliferation and differentiation determinants and explores their potential clinical implications in oral and periodontal surgery. Materials and Methods: A comprehensive electronic search was conducted across Medline/PubMed, Embase, Scopus, and Web of Science for articles published up to May 3, 2025. Inclusion criteria were limited to in vitro studies, written in English, investigating osteogenic proliferation and differentiation of hMSCs or human osteoblast-like cells on xenograft granule-shaped or block-formed scaffolds. The risk of bias in the included studies was assessed using established parameters for cell culture research. Results: The review included 22 studies out of 931 screened articles. Deproteinized bovine bone mineral (DBBM) was the most frequently investigated biomaterial. Alkaline phosphatase (ALP) activity, osteocalcin immunoassay, and morphological analysis were identified as key tools for assessing in vitro osteoblast differentiation. Significant heterogeneity in scaffold composition and experimental design precluded meta-analysis, and results were synthesized narratively. Conclusions: Xenogeneic bone substitutes, particularly DBBM, demonstrate optimal osteoconductivity in vitro . While these in vitro findings suggest potential for clinical application, the heterogeneity of existing research highlights the need for well-designed in vivo studies and clinical trials to validate these results and establish optimal bone scaffold materials and strategies for oral and periodontal surgery. Clinical Relevance: Biofunctionalization and cell-to-scaffold contact are essential clinical requirements for attachment and integration of bone grafts. Biologically, a deeper understanding of the specific roles, reliability, and optimal conditions for applying bone substitutes in clinical applications is required.