Ridge preservation after ridge expansion with simultaneous guided bone regeneration: a preclinical study

Facile one-step antibacterial biomineralized scaffolds through regulation of chitosan by imitating bone ingredient bonding to inspire endogenous repair

In situ mineralization based on chitosan (CS) as an organic template achieves uniform distribution of nano-hydroxyapatite (nHAp), and is expected to enhance interface bonding between materials and tissues, therefore promoting endogenous bone repair. However, chitosan-based materials are difficult to provide certain mechanical and antibacterial properties. In this study, Ca2+ and PO43- were used as the precursor of nHAP, Zn2+ as the precursor of nano-ZnO, and synthesized nHAp/ZnO particles in situ on the surface of chitosan to form CS/HAp/ZnO bone repair scaffold. The results indicated that the incorporated Zn2+ was chemically bonded to the system, with formed particles evenly distributed, which achieved more efficient antibacterial activity and osteogenic induction performance in vivo. The material had interconnected pore structure with a porosity of >70 %, which simulates the microenvironment of natural bone. The formed inorganic particles improved the mechanical properties of the chitosan scaffold to match the rate of new bone formation. ZnO endowed scaffolds with antibacterial activity, with antibacterial rate of >95 %. In addition, the material also showed good cell compatibility and biological activity, and promoted the adhesion, migration, proliferation and differentiation of osteoblast-related cells.

Polydioxanone Membrane Compared with Collagen Membrane for Bone Regeneration

Guided bone regeneration (GBR) is an approach that induces osteopromotion through the regenerative membranes. These barriers exhibit bioactive behavior and mechanical function. Polydioxanone is a synthetic option, already used in medicine and dentistry, with good results in bone regeneration. This study aimed to evaluate bone repair in critical defects in rat calvaria using a polydioxanone membrane (Plenum^® Guide) compared with a commercially available collagen-based membrane (Bio-Gide^®). The bone defects were filled with Plenum^® Osshp, a synthetic bone graft, hydroxyapatite:β-tricalcium phosphate, 70:30%, Group PG (Plenum^® Guide + Plenum^® Osshp), and Group BG (Geistlich Bio-Gide^® + Plenum^® Osshp). The specimens were submitted to immunohistochemical (RUNX2 and OPN), gene expression (RUNX2, IBSP, and VEGF), histometric, and microtomography analyses after 07, 15, 30, and 60 days postoperative. PG group showed greater immunolabeling area for RUNX2 and OPN, higher gene expression of VEGF (3.15 ± 0.85), and IBSP (24.9 ± 0.59). However, there was no statistical difference between groups in the histometric analysis regarding the percentage of connective tissue PG (0.83 ± 0.45), BG (0.70 ± 0.34), neoformed bone PG (0.60 ± 0.4), BG (0.65 ± 0.51), and remaining biomaterial PG (0.84 ± 0.31), BG (0.91 ± 0.33). In addition, there was no statistical difference between groups by micro-CT analysis. The absorbable-synthetic membrane, Plenum^® Guide, is an effective membrane for guided bone regeneration.

Mineralized Collagen: Rationale, Current Status, and Clinical Applications

This paper presents a review of the rationale for the in vitro mineralization process, preparation methods, and clinical applications of mineralized collagen. The rationale for natural mineralized collagen and the related mineralization process has been investigated for decades. Based on the understanding of natural mineralized collagen and its formation process, many attempts have been made to prepare biomimetic materials that resemble natural mineralized collagen in both composition and structure. To date, a number of bone substitute materials have been developed based on the principles of mineralized collagen, and some of them have been commercialized and approved by regulatory agencies. The clinical outcomes of mineralized collagen are of significance to advance the evaluation and improvement of related medical device products. Some representative clinical cases have been reported, and there are more clinical applications and long-term follow-ups that currently being performed by many research groups.