Correction: TiO2 nanotube stimulate chondrogenic differentiation of limb mesenchymal cells by modulating focal activity.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Influence of Fixture Thread Exposure on Marginal Bone Level Around Different Implant Systems: A Preliminary Study in Dogs.

PURPOSE: To evaluate the influence of implant neck structures on marginal bone loss around intentionally exposed implant fixtures by histomorphometric analysis. MATERIALS AND METHODS: Twenty-four implants representing 3 implant systems were placed in three dogs; an implant system with SLA surface without microthreads (group A); one with SLA + calcium surface without microthreads (group B); and one with SLA surface with microthreads (group C). The histomorphometric analyses for vertical defect length (VDL), infrabony defect height (IDH), and defect depth (DD) were performed at the buccal and lingual sides of each fixture. RESULTS: The VDL was lower in group A relative to groups B and C on the buccal and lingual sides. The IDH and DD were higher in group A than group C on the buccal and lingual sides; however, no statistically significant differences were noted between the groups in VDL, IDH, and DD on the buccal and lingual sides of the fixtures. CONCLUSIONS: In this preliminary study, marginal bone resorption pattern in the canine mandible varied according to the neck design of each implant fixture. Further studies with larger sample size are needed to confirm the effect of microthreads and surface roughness on the marginal bone loss at the exposed implant fixture.

Novel application of the 2-piece orthodontic C-implant for temporary crown restoration after orthodontic treatment.

INTRODUCTION: This article reports the use of an orthodontic mini-implant for a temporary crown restoration in a small edentulous space after limited orthodontic treatment. METHODS: Two clinical cases are presented: a 23-year-old woman and a 14-year-old boy. In the adult patient, a 2-piece orthodontic C-implant (Cimplant, Seoul, Korea) was placed in a 3-mm wide edentulous space to build up a temporary crown restoration after a short orthodontic treatment to regain space for a missing mandibular right permanent lateral incisor. In the boy, a C-implant was placed in the space resulting from an avulsed maxillary right permanent lateral incisor to prevent aggressive alveolar bone resorption after dental trauma. Both patients were followed for more than 4 years of retention to evaluate the stability of the temporary crown restoration built up on the orthodontic mini-implants. RESULTS: Both patients had successful long-term results, confirmed by clinical and radiographic examinations. Both were pleased with the results and plan to retain the orthodontic mini-implant temporary crown restoration until they are ready for a permanent restoration later. CONCLUSIONS: A 2-piece orthodontic C-implant system can be used to maintain edentulous space after active orthodontic treatment.

TiO2 nanotube stimulate chondrogenic differentiation of limb mesenchymal cells by modulating focal activity.

Vertically aligned, laterally spaced nanoscale titanium nanotubes were grown on a titanium surface by anodization, and the growth of chondroprogenitors on the resulting surfaces was investigated. Surfaces bearing nanotubes of 70 to 100 nm in diameter were found to trigger the morphological transition to a cortical actin pattern and rounded cell shape (both indicative of chondrocytic differentiation), as well as the up-regulation of type II collagen and integrin beta4 protein expression through the down-regulation of Erk activity. Inhibition of Erk signaling reduced stress fiber formation and induced the transition to the cortical actin pattern in cells cultured on 30-nm-diameter nanotubes, which maintained their fibroblastoid morphologies in the absence of Erk inhibition. Collectively, these results indicate that a titanium-based nanotube surface can support chondrocytic functions among chondroprogenitors, and may therefore be useful for future cartilaginous applications.

Clinical application of a stereolithographic surgical guide for simple positioning of orthodontic mini-implants.

AIM: To describe a clinical application of a new surgical guide system that uses cone-beam computed tomography (CBCT) images, an implant-positioning program (SimPlant), and stereolithography to make a surgical guide for accurate placement of orthodontic mini-implants. METHODS: A patient who was planning to have orthodontic mini-implant treatment on the posterior maxilla was recruited to assess the feasibility of using CBCT images in an implant-positioning guide program (SimPlant 9.02, Materilise, Leuven, Belgium). Acquisition slices for the posterior maxilla were 0.15 mm in panoramic mode of PSR 9000N model (Asahi Roentgen, Kyoto, Japan). The surgical guide for the mini-implant was fabricated from the transported CBCT data. RESULTS: The completed surgical guide was easily placed intra-orally and permitted simple and rapid placement of the mini-implant. The site of the implant placement was accurate, while the vector varied slightly from the planned vector. CONCLUSION: A postplacement CBCT demonstrated accurate placement of the mini-implant on the left and a minor discrepancy between the simulated mini-implant position and clinical position on the right. Improvements in the CBCT resolution and laser-scanning technology are likely to eliminate any discrepancies.