Early Osseointegration of Implants with Cortex-like TiO2 Coatings Formed by Micro-arc Oxidation:A Histomorphometric Study in Rabbits

In our previous studies, a novel cortex-like Ti O2 coating was prepared on Ti surface through micro-arc oxidation（MAO） by using sodium tetraborate as electrolyte, and the effects of the coating on cell attachment were testified. This study aimed to investigate the effects of this cortex-like MAO coating on osseointegration. A sand-blasting and acid-etching（SLA） coating that has been widely used in clinical practice served as control. Topographical and chemical characterizations were conducted by scanning electron microscopy, energy dispersive X-ray spectrometer, X-ray diffraction, contact angle meter, and step profiler. Results showed that the cortex-like coating had microslots and nanopores and it was superhydrophilic, whereas the SLA surface was hydrophobic. The roughness of MAO was similar to that of SLA. The MAO and SLA implants were implanted into the femoral condyles of New Zealand rabbits to evaluate their in-vivo performance through micro-CT, histological analysis, and fluorescent labeling at the bone-implant interface four weeks after surgery. The micro-CT showed that the bone volume ratio and mean trabecular thickness were similar between MAO and SLA groups four weeks after implantation. Histological analysis and fluorescent labeling showed no significant differences in the bone-implant contact between the MAO and SLA surfaces. It was suggested that with micro/nanostructure and superhydrophilicity, the cortex-like MAO coating causes excellent osseointegration, holding a promise of an application to implant modification.

The influence of the eruption of mandibular third molars on the craniofacial morphology in Han youth of North China

Teeth affect not only oral problems but also facial morphology.In China,there are few reports about the influence of the third molars on the craniofacial morphology of Han youths.Using in vivo imaging software,3D reconstruction of craniofacial CTs were performed on 32 Chinese Han youths without mandibular third molars and 25 Chinese Han youth with full mandibular third molars.The morphology of their mandible and mandibular tissue was measured to identify differences.Among the morphological characteristics of hard tissues,except for∠ANB,people with a full eruption of the mandibular third molars had statistically significantly larger angle indicators than people without the eruption of the third molars.The soft tissue indicators also showed statistically significant discrepancies in terms of morphological facial height,mouth to gnathion distance,lip height,and mouth breadth.The most influential index for mandibular third molars was length of symphysis,followed by the four indicators of soft tissue and mandible length and height.Morphology facial height,mouth to gnathion distance,lip height,and height of symphysis were moderately correlated.The experimental results show that among Han youth in North China,the third molar eruption has a widespread influence on mandibular morphology,especially in angle,length,and height indicators.It also has a certain influence on maxillofacial soft tissue morphology.These results can be applied to future clinical risk assessment of the wisdom teeth and forensic personal identification of the cranial and maxillofacial region.