In Vivo Studies

Repairing temporary fixed dental prostheses can cause inconvenience and lost productivity to patients. To choose the suitable biomaterials for the special needs of different patients, clinicians must know about the strengths and weaknesses of numerous biomaterials [84]. Barry et al. used the technique of glass fiber reinforcement to improve the strength, longevity and curative effect of the definitive fixed prosthodontic treatment [85]. Fiber-reinforced interim restorations were applied for longer-term periods in clinical situations indicating multiple pontic spaces or in patients with heavy occlusal function. Kumbuloglu et al. evaluated the clinical performance of indirect, anterior, surface-retained, fiber-reinforced composite restorations (FRCR) [86]. There were 134 patients (51 males, 83 females, 6-8 years old) received the FRCR tests. The restorations were used unidirectional E-glass fibers combined with a laboratory resin composite to cement indirectly on a plaster model. All the patients were followed at 6 months and then annually up to

7.5 years after baseline recordings. The evaluation protocol involved technical (chipping, fracture or debonding of tooth/restoration) and biological failures (caries). The results were 13 failures, 1 catastrophic fracture, eight partial debonding and four delaminations of veneering composite. The restorations FRCR showed similar clinical survival rate after cemented with the resin cement. Experienced failures generally were owing to delamination of the veneering composite or debonding of the restoration. The FRCR could be considered cost-effective alternatives to conventional tooth- or implant-bonded fixed dental prosthesis.

To understand the osteogenesis effect of the tubular nanostructure, Lee et al. compared the osteogenesis bioactivity of nanotube Ti and pure Ti loaded with N-acetyl cysteine. After 4 weeks implantation, a large number of osteogenic growth factor, like BMP-2 and BMP-7, were shown on the surface of implants (Fig. 7.3). Moreover, the bone inflammatory marker (Receptor Activator for Nuclear Factor-к B Ligand, RANKL) was clearly less in the regenerated bone around nanotube Ti filled composites compare to pure Ti filled implants [76].

Mendes et al. studied the influence of single-walled carbon nanotube (SWCNT) reinforced sodium hyaluronate (HY-SWCNT) scaffold on tooth sockets regeneration in vivo. The scaffolds, which increased nearly three folds, obviously enhanced the formation of bone trabecula compare with the control sockets. Furthermore, the expression level of collagen I was dramatically improved after a week of tooth extraction [87]. This result further demonstrated that SWCNT plays a positive effect on accelerating the formation of new bone in sockets. Likewise, Sa et al. came to similar conclusions on the osteogenesis effects of HY-SWCNT acted as tooth socket scaffolds. In this study, HY-SWCNT scaffold was implanted in rats with type I diabetes. The implantation sharply enhanced the formation of bone trabecula, whose final values approach to those obtained in non-diabetic rats [88]. In a word, SWCNT reinforced scaffolds have great advantages in dental regeneration, whether normal or unhealthy metabolic condition.

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