BACKGROUND: At present, composite resin has been dominantly applied on bonding brackets, but dental enamel is prone to the injury on the surface when the brackets are removed, resulting from the high bonding strength. OBJECTIVE: To compare the shear bond strength and adhesive remnant index of three orthodontic bonding adhesives at 5 minutes and 15 minutes after bonding orthodontic brackets. DESIGN, TIME AND SETTING: A randomized grouping control experiment was completed in the Laboratory of Stomatology, General Hospital of Shenyang Military Area Command of Chinese PLA from June to October in 2007. MATERIALS: For the sake of orthodontic, 90 premolars were extracted from the volunteers, who signed the informed consents to the study. Buccal surface enamel was observed under 10-power magnifying glass to be intact and untreated, without crack or dental caries, excluding tetracycline stained teeth and dental fluorosis. Jingjin enamel adhesive (Tianjin); light-cured resin modified glass ionomer cement (RMGIC) adhesive (Fuji, GC, Japan); Transbond XT and self-etching primer (3M Uniteck). METHODS: Ninety teeth were randomly allocated into three groups (n=30) as follows: Jingjin enamel adhesive group, light-cured RMGIC adhesive group, and self-etching adhesive group. After bonding, the brackets of the three groups were removed at 5 minutes and 15 minutes, respectively. There were 15 teeth at each time point. MAIN OUTCOME MEASURES: The shear bond strength and adhesive remnant index were measured and scored as 1-5 points (higher scores indicated higher bonding strength between the adhesives and the teeth, whereas lower scores indicated higher bonding strength between the adhesives and the brackets). RESULTS: After the bracket removal, the shear bond strength of light-cured RMGIC adhesive group was the lowest. No significant difference was found in the shear bond strengths between Jingjin enamel adhesive group and self-etching adhesive group. The remnant adhesives equally distributed on the teeth surface and bracket surface in Jingjin enamel adhesive group and self-etching adhesive group, while mainly distributed on the bracket surface in light-cured RMGIC adhesive group. The adhesive remnant index scores showed statistically significant differences among three groups (P

Objective: To study the vitro bioactivity of the Ti-24Nb-4Zr-7.9Sn (TNZS) disks modified by anodic oxidation(AD) and its effects on adhesion of human osteoblast-like MG63 cells. Methods:The TNZS titanium alloy disks were treated with anodic oxidation and the bioactivity was assessed by investigating the formation of apatite on the film surface after soaking in simulated body fluids. The surface composition of the specimens after immersion was evaluated by EDX and X-ray diffraction. MG63 osteoblast-like cells were seeded on the Ti6Al4V,TNZS,AD-TNZS disks, and then the number of attached cells were counted and the cell morphology was examined at each given period. Results:The apatite can form on the treated TNZS disks after soaking in SBF for 6 days. The ratio of attached MG63 on AD-TNZS disks after 60 or 120 min seeding were significant higher than that on other samples and the cells on AD-TNZS disks spread better. Conclusion:The TNZS alloy modified by anodic oxidation can induce apatite formation in SBF and increase the early attachment of osteoblasts.

Objective: To study surface landmark of the blood vessles i n subtemporal parapharyngeal region. Methods:6 corpse heads were dissected, the anatomical character and the ralationship between surface landma rks and blood vessels was observed. Results:The distance between inferior medial point of meatus acusticus externus and internal jugular vein fo ramen was (11.5?2.0) mm, that between medial margin of condyle process and in ternal artery foramen was (10.0?1.3) mm. Internal carotid artery was (12.0? 3.0) mm away from posterior margin of mandibular horn, internal jugular vein wa s (5.0?2.0) mm in front of the transverse process of the first cervical verte brae (S1).Conclusions:The inferior point of meatus acustics exte rnus, anterior point of condyle process, mandibular horn and transverse process of S1 can be used as surface landmarks for internol jugular vein and carotid art ery.

OBJECTIVEThe purpose of this study was to determine the incidence of temporary and permanent sensory disturbance of the inferior alveolar nerve (IAN) after bilateral sagittal split osteotomy (BSSO) of the mandible.

METHODS14 patients were selected for this study. Before BSSO and at 1 week, 1, 3, 6 and 12 months after BSSO, the sensibility of bilateral inferior alveolar nerves were examined using sharp-blunt testing, 2-point discrimination, electronic pain response test (ZGK-1 electrometer).

RESULTSWith conventional sharp-blunt and 2-point discrimination test, electronic pain response test, the incidence of temporary impairment of IAN after BSSO was 78% (22/28). Obvious sensory recovery of IAN was found 6 to 12 months postoperatively. Permanent sensory disturbance of unilateral inferior alveolar nerve occurred in 2 patients.

CONCLUSIONSSensory recovery of the inferior alveolar nerve after bilateral sagittal split osteotomy of the mandible would take 6 to 12 months. Serious injury of the IAN would cause permanent neurosensory deficits.

Adolescent ; Adult ; Female ; Humans ; Male ; Mandible ; surgery ; Mandibular Nerve ; physiopathology ; Oral Surgical Procedures ; adverse effects ; Osteotomy ; adverse effects ; methods ; Sensory Thresholds ; Trigeminal Nerve Injuries