正畸儿童龋病的口腔综合防治

目的：观察口腔综合防治措施对正畸儿童龋病的作用。方法：以56名12-16岁的正畸患者为观察对象，观察矫治前、矫治后半年及1年的龋指数、变形链球菌计数、乳酸杆菌计数的改变。实验组采用口腔综合保健措施。结果：实验组的变形链球菌计数、乳酸杆菌计数明显低于对照组，差异有显著性；实验组无新龋发生，对照组龋均比实验组有所上升，但两组之间无统计学上的差异。结论：正畸治疗患者龋病通过口腔综合防治措施是可以治疗和预防的。     

Prospective evaluation of implants connected to teeth

PURPOSE: This prospective clinical trial examined the effect on teeth and implants when rigidly or non-rigidly connected in a cross-arch model. MATERIALS AND METHODS: Thirty patients received 2 implants, 1 on each side of the mandible, and were restored with 3-unit fixed partial dentures connected either rigidly or non-rigidly to an abutment tooth. Patients were followed for at least 5 years post-restoration. RESULTS: Repeated-measures analysis revealed no significant difference in crestal bone loss at implants (rigid versus non-rigid methods). An overall significant difference (P < .001) was found comparing methods for teeth. Paired t tests revealed no significant differences in crestal bone levels for implants or teeth at the 5-year recall. Kaplan-Meier methods and the Cox proportional hazards model showed no differences between attachment methods with regard to success based on survival and bone loss criteria. During the 5-year recall period, 1 implant (rigid side) was removed. Four implants developed bone loss greater than 2 mm during the course of this trial. One tooth on the rigid side and 2 teeth on the non-rigid side had greater than 2 mm of crestal bone loss and were removed secondary to fractures. In all, 5 abutment teeth were removed, all of which had been treated with root canal therapy and fractured at the interface of the post within the tooth. There was no clear relationship of tooth fracture to attachment. Repeated-measures analysis of mobility values revealed no significant changes over the time course of this study, and paired t tests revealed no statistically significant differences between implants for mobility. Repeated-measures analysis and paired t tests for probing depth revealed no significant changes over the time course of this study. There were no significant differences in soft tissue indices for either attachment method. The percentage of patients who had measurable intrusion was 66% for the non-rigid group, and 44% for the rigid group; 25% of the non-rigid teeth had greater than 0.5 mm intrusion, compared with 12.5% for the rigid group. For the 2 time periods evaluated, there was no significant increase in intrusion over time. The non-rigid-side implant required more nonscheduled visits to treat problems than the rigid implant and the teeth. Discussion: Most patients were treated successfully with rigid or non-rigid attachment of implants to teeth. CONCLUSION: The high incidence of intrusion and non-scheduled patient visits suggest that alternative treatments without connecting implants to teeth may be indicated.     

Lack of effect of chlorhexidine varnish on Streptococcus mutans transmission and caries in mothers and children

In a randomized clinical trial, we evaluated the effect of a 10% chlorhexidine varnish (Chlorzoin) on the mother-child transmission of Streptococcus mutans and on subsequent caries experience. Chlorhexidine (n = 38) or a placebo varnish (n = 37) was applied to the dentitions of 75 mothers at a time when their first babies were about 6 months old (approximate time of first tooth emergence). Three more applications at weekly intervals and subsequent applications at 6-month intervals followed the initial application. The mother-child pairs were followed up until the child's fourth birthday. Maternal salivary S. mutans levels in the treatment group remained significantly lower (p < 0.05) compared to the control group up to 12 months after the initial application. However, this intervention did not significantly alter the S. mutans colonization in children or the caries increment in either the mother or the child.     

mcpr1基因的真核表达载体的构建与鉴定

目的 :构建腭裂相关基因mcpr1与pcDNA3 .1/V5 HisB融合的高效真核表达载体 ,为研究mcpr1基因的功能奠定基础。方法 :根据mcpr1基因的核苷酸序列 ,设计并合成引物 ,通过PCR方法 ,从包含有mcpr1基因全长的克隆载体T easy/mcpr1中 ,扩增出该基因外显子片段 ,将扩增产物连接到真核表达载体pcDNA3 .1/V5 HisB中。对该重组体进行PCR和酶切鉴定 ,以及测序验证。结果 :以重组体为模板扩增出40 0bp左右的特异性基因片段 ,与mcpr1基因片段大小一致 ,酶切鉴定也显示有 40 0bp左右的基因片断。测序结果显示与已知基因序列一致。结论 :成功构建mcpr1基因的真核表达载体 ,为下一步研究mcpr1基因的功能奠定了基础。     

Microvessel density and expression of vascular endothelial growth factor, basic fibroblast growth factor, and platelet-derived endothelial growth factor in oral squamous cell carcinomas

Angiogenesis, the growth of capillary vessels, plays an important role in the metabolic functions of malignant tissues. Tumor growth and malignant transformation are considered to be dominated by uncontrolled angiogenesis. To understand the mechanism of increased vascularity associated with malignant tissues, we immunohistochemically evaluated microvessel density (MVD) and the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and platelet-derived endothelial growth factor (PDGF) in oral cancers. Microvessel density did not differ significantly between normal oral mucosa and epithelial dysplasia, but was significantly increased in tumor tissues. Expression of angiogenic factors was not found in normal oral mucosa, but increased in association with increasing vascularity in OSCC tissue. In tumor tissue, angiogenic factor expression correlated with MVD. MVD in OSCC was related to T stage, tumor differentiation, and stage of invasion. VEGF expression also correlated with tumor differentiation and the stage of invasion. These findings suggest that VEGF might play an important role in tumor angiogenesis of OSCC.     

热压技术制作烤瓷嵌体的实验研究

比较常规法和热压法所制作的实验标本挠屈强度的差异及两种方法所制作嵌体密合度的差异。采用双轴向三点支撑法测量实验标本的挠屈强度，用工具显微镜测量嵌体的密合度。结果表明，两种方法所制作的实验标本的挠屈强度无显著性差异（Ｐ＞０．０５）。用热压法制作的嵌体的密合度优于常规法（Ｐ＜０．０１）。热压技术设备简单、操作方便，可以提高瓷嵌体边缘密合度及外形准确性     

煅石膏、骨形成蛋白及羟基磷灰石三元复合人工骨修复骨缺损的实验研究

以煅石膏(PLP）作为颗粒型羟基磷灰石(HA)人工骨粘接成形剂和骨形成蛋白(BMP)的载体，制成三元复合人工骨．分别用HA—bBMP、HA—PLP和单纯HA植入狗下颌骨实验性骨缺损中，采用组织学、定量组织学、免疫组织化学、X线摄片和扫描电镜观察的方法评价该复合人工骨的生物学性能。术后1，2，4，8和16周观察发现，HA—bBMP—PLP复合人工骨具有明显的骨诱导活性．PLP可充当BMP缓慢释放系统载体．增强BMP骨诱导活性，和作为颗粒型HA的粘接成形剂．使复合人工骨具有一定的可塑性和成形性，可达到准确的植入，植入后早期可有效防止HA颗粒移动。本研究证实．HA—bBMP—PLP三元复合人工骨不但可限制植入后HA颗粒的早期移动，更重要的是可以迅速增加新骨形成量．从形态和功能上大大提高了复合人工骨修复骨缺损的质量。     

半负荷状态下即刻和延期植入种植体的实验研究

选择3种不同种植体采用即刻和延期两种方式植入5只狗的下颌前磨牙及第一磨牙区内,呈半负荷状态,分别于术后 2.4.6.8.12.24周取出标本作X线.LM SEM观察,结果显示:3个月时所有种植体均已达到完善骨整合,成骨量和骨小梁排列方向与(牙合)力负荷一致,且在同一机体上,骨整合无显著性差异,不同种值体之间8周时骨整合己无差异.     

三种类型骨内牙种植体的临床修复设计

作者将三种类型国产骨内牙种植体——羟基磷灰石涂层钛合金二段式种植体（HA-Ti)，纯钛叶状种植体（Ti-Blade)，纯钛螺旋状种植体（Ti-Screw)共35枚植入21例患者上下颌骨内，均已作永久性修复，临床观察19-48个月，除4枚已取出外，其余尚留于口中行使功能。作者认为，适当选择适应证，合理设计上部修复体对3种类型国产牙种植体的成败至关重要。     

高角儿童面颈部肌肉的肌电活动研究

目的研究高角儿童在不同下颌运动时面颈部肌肉的肌电活动情况。方法用BioEMGⅡ型肌电图仪同步记录14名高角儿童和16名均角儿童在不同下颌运动时双侧颞肌前束(TA)、咬肌(MM)、胸锁乳突肌(SCM)和二腹肌前腹(DA)的肌电活动。结果下颌息止位时,高角组TA、DA和SCM的肌电活动低于均角组,有统计学意义(P<0.01,P<0.05);最大紧咬时,高角组TA和MM的肌电活动低于均角组,有统计学意义(P<0.05);咀嚼口香糖时,高角组MM的肌电活动低于均角组,有统计学意义(P<0.05);吞咽时高角组DA的肌电活动低于均角组,有统计学意义(P<0.05)。结论不同下颌运动时,高角儿童和均角儿童面颈部肌肉的肌电活动差异有所不同;面颈部肌肉的肌电活动可能与颅面垂直形态有关。