Preservation and Regeneration of Alveolar Bone by Tissue-Engineered Implants

Abstract

Bone maintenance after dental extraction has a significant impact on the success of future treatment. The purpose of this study was to regenerate bone by implanting an engineered porous scaffold seeded with bone marrow mesenchymal stem cells (BMSCs) in a socket created by extraction of the lower left central incisor in rabbits, utilizing the principles of tissue engineering. It involved preparation and characterization of three-dimensional porous hollow root form scaffolds consisting of a poly-L-lactic acid:polyglycolic acid composite (PLG, 50:50), using a solvent casting/compression molding/particulate leaching technique. Porosity of the scaffolds was 83.71% with good interconnectivity and uniform distribution of the various pore sizes. The degraded scaffolds maintained their porosity and form for the first 2 weeks and their mass loss continued up to 6 weeks. The scaffolds developed viscoelastic behavior under dynamic compression; yet they lost their mechanical characteristics as they degraded. The scaffolds were seeded with BMSCs and examined by scanning electron microscopy. Cell proliferation and scaffold degradation were shown up to 2 weeks in vitro. The cultivated scaffolds were implanted in empty extraction sockets immediately after tooth removal. Four weeks later, bone regeneration was evaluated histologically in the healed sockets in three experimental groups: sockets left empty, sockets that received PLG without cells, and sockets that received PLG with cells. Radiographic evaluation, performed 4 weeks later for the three experimental groups, demonstrated preservation of alveolar bone walls in the extraction sockets that received PLG with cells as compared with the other two groups. The bone density profile for the healed sockets confirmed both histological and radiographic findings. The results of this study show promise in the area of dentoalveolar surgery, yet longitudinal studies under variable clinical situations would encourage the current application.

Nanoporosity Significantly Enhances the Biological Performance of Engineered Glass Tissue Scaffolds

“…The wounds were then sutured using 3.0 silk suture material. 45 At 1 and 2 weeks postsurgery, full thickness specimens including the implants were excised, immediately placed in 10% formalin fixative, and stepwise dehydrated in graded concentrations of ethyl alcohol. Specimens were cleaned in xylene, followed by embedding in methyl methacrylate resin (Aldrich) for histological hard-section preparation.…”

Ridge preservation: what is it and when should it be considered

“…Cultivated scaffolds from bone marrow mesenchymal stem cells have been placed into fresh extraction sockets with results that ''show promise''. 40 …”

Molars extraction for bone graft study in rabbits

“…Schmitz and Holliger 6 , in their experiments, described some models of bone lesions in different sites such as the calvaria and mandible without reporting the changes in the jaw bone of rabbits 9 . Bone defects caused in the region of the mandible body 15 x 10mm in rabbits were used for studies of bone grafts with the aid of fixing 10,14 . A surgical model with a bone store was proposed to be used to evaluate bone graft without fixation and protection using the alveoli of the molars of the rabbit.…”

“…However, this roots have large curvature and hampers their extraction 9,10 . The use of extra-oral access decrease the surgical difficulty and the biomaterial can be used up at four teeth sockets with similar proportions in the same animal and resulting in less amount of animals required.…”