血液环境下Biodentine与MTA的颜色稳定性研究

目的 比较牙体牙髓治疗中常用的骨水泥材料Biodentine与三氧化矿物凝聚体(mineral trioxide ag-gregrate,MTA)在与血液接触条件下的颜色稳定性,并探讨其可能的变色原因.方法 制备直径5 mm、高3 mm的Biodentine和MTA圆盘,将每种材料的24个圆盘随机分配到去离子水组和脱纤...     

Rhombohedral Phase Formation in Yttria-Stabilized Zirconia Induced by Dental Technical Tools and Its Impact on Dental Applications

In the study the influence of different dental technical tools on the surface temperature and phase composition of fixed dental prostheses (FDPs) made of yttria-partially stabilized zirconia polycrystals (3Y-/4Y-/5Y-PSZ) was investigated. FDPs were fabricated by using computer-aided manufacturing (CAM). The FDPs were treated with a contra-angle handpiece equipped with different burs and polishers. The resulting surface temperatures were measured with a thermographic camera, and the resulting phase transformations were investigated by X-ray diffraction and quantified by Rietveld refinement. Processing with burs resulted in no phase transformation, but a preferred orientation shift. Using coarse polisher induced a phase transformation to the rhombohedral phase, while fine polishers produced no relevant phase transformations and no preferred orientation shift. Compared to the monoclinic phase (ca. 9% theoretical volume increase), which is associated with low-temperature degradation (LTD), the rhombohedral phase is much more voluminous (ca. 15% theoretical volume increase) and distorted and, therefore, has a greater degradation potential.     

Marginal bone level change during sequential loading periods of partial edentulous rehabilitation using immediately loaded self-tapping implants: a 6.5-year retrospective study

PURPOSEA large number of studies have suggested the practicability and predictability of immediate implant function, but few studies have reported marginal bone level changes during sequential loading periods. The purpose of this study was to evaluate the marginal bone remodeling of immediately loaded self-tapping implants both at each time point and during each loading period between two time points.MATERIALS AND METHODSThe patients included in this retrospective study were treated with immediately loaded NobelSpeedy Replace implants between August 2008 and July 2009. Differences in the marginal bone level (MBL) at each time point and the marginal bone level change (ΔMBL) between two time points were analyzed with Bonferroni correction (P < .05).RESULTSOverall, 24 patients (mean age, 47.3 ± 12.8 years) with 42 immediately loaded implants and a median follow-up of 6.5 years (IQR, 67.8 months) were included. The cumulative survival rate after 10 - 12 years was 95.2%. Continuous but slow marginal bone loss was observed during long-term follow-up. MBL at both 7.5 years and 11 years was significantly lower than that at loading, 6 months, 2 years and 4 years (P < .05). No bone loss difference was found in any period before 4 years of follow up (P > .05). The loading period of 4 years to 7.5 years showed the largest ΔMBL compared to those of other time periods (P < .05).CONCLUSIONSlight bone loss occurred continuously, and more radical changes of marginal bone can be observed during the period of 4-7.5 years. Thus, long-term effective follow-up of immediately loaded implants is needed.     

Intrusion of overerupted molars with temporary anchorage devices before prosthetic reconstruction: A case report

Extraction of teeth without adequate prosthetic rehabilitation frequently can lead to overeruption of opposing teeth, which may cause occlusal disturbances and complicate dental restoration. Equilibration with consequent need of endodontic treatment, surgical intrusion or extraction are often indicated as a remedy in such cases. The article proposes a method of orthodontic intrusion with the use of temporary anchorage devices as a predictable and less invasive option. Important clinical aspects of molar intrusion with respect to surrounding anatomical structures are also discussed.     

Influence of Xenogeneic and Alloplastic Carriers for Bone Augmentation on Human Unrestricted Somatic Stem Cells

Alloplastic and xenogeneic bone grafting materials are frequently used for bone augmentation. The effect of these materials on precursor cells for bone augmentation is yet to be determined. The aim of this study was to ascertain, in vitro, how augmentation materials influence the growth rates and viability of human unrestricted somatic stem cells. The biocompatibility of two xenogeneic and one alloplastic bone graft was tested using human unrestricted somatic stem cells (USSCs). Proliferation, growth, survival and attachment of unrestricted somatic stem cells were monitored after 24 h, 48 h and 7 days. Furthermore, cell shape and morphology were evaluated by SEM. Scaffolds were assessed for their physical properties by Micro-CT imaging. USSCs showed distinct proliferation on the different carriers. Greatest proliferation was observed on the xenogeneic carriers along with improved viability of the cells. Pore sizes of the scaffolds varied significantly, with the xenogeneic materials providing greater pore sizes than the synthetic inorganic material. Unrestricted somatic stem cells in combination with a bovine collagenous bone block seem to be very compatible. A scaffold’s surface morphology, pore size and bioactive characteristics influence the proliferation, attachment and viability of USSCs.     

运用Demirjian法测量替牙早期前牙反合患者的牙龄研究

目的 评估Demirjian法测定天津地区儿童的牙龄的适用性.方法 运用Demirjian法测定天津地区替牙早期前牙反合患者治疗期间牙龄的变化量,并与实际年龄的变化量进行比较分析.结果 Demirjian法测定的牙龄变化量无论男性组还是女性组与实际年龄变化量均无显著性差异.结论 Demirjian法适用于中国天津地区替牙前期前牙反合患者牙龄的测定.     

Comparison of Signal and Gap-Detection Thresholds for Focused and Broad Cochlear Implant Electrode Configurations

Cochlear implant (CI) users usually exhibit marked across-electrode differences in detection thresholds with “focused” modes of stimulation, such as partial-tripolar (pTP) mode. This may reflect differences either in local neural survival or in the distance of the electrodes from the modiolus. To shed light on these two explanations, we compared stimulus-detection thresholds and gap-detection thresholds (GDTs) at comfortably loud levels for at least four electrodes in each of ten Advanced Bionics CI users, using 1031-pps pulse trains. The electrodes selected for each user had a wide range of stimulus-detection thresholds in pTP mode. We also measured across-electrode variations in both stimulus-detection and gap-detection tasks in monopolar (MP) mode. Both stimulus-detection and gap-detection thresholds correlated across modes. However, there was no significant correlation between stimulus-detection and gap-detection thresholds in either mode. Hence, gap-detection thresholds likely tap a source of across-electrode variation additional to, or different from, that revealed by stimulus-detection thresholds. Stimulus-detection thresholds were significantly lower for apical than for basal electrodes in both modes; this was only true for gap detection in pTP mode. Finally, although the across-electrode standard deviation in stimulus-detection thresholds was greater in pTP than in MP mode, the reliability of these differences—assessed by dividing the across-electrode standard deviation by the standard deviation across adaptive runs for each electrode—was similar for the two modes; this metric was also similar across modes for gap detection. Hence across-electrode differences can be revealed using clinically available MP stimulation, with a reliability comparable to that observed with focused stimulation.     

人工肱骨头置换治疗老年肱骨近端复杂骨折

目的 探讨应用人工肱骨头置换治疗老年肱骨近端复杂骨折的手术适应证、手术时机、操作要点及术后康复等.方法 选取我院2009年1月至2012年3月收治的老年肱骨近端Neer三、四部分骨折行人工肱骨头置换术患者25例,男15例,女10例;年龄64.0～89.0岁,平均73.6岁.手术中均假体植入得当,准确复位固定大小结节,修复肩袖,术后早期分阶段功能康复锻炼.随访应用Neer肩关节功能评分标准评估疗效.结果 手术时间60～110 min,平均80 min;术后随访9～24个月,平均14个月.所有患者均无感染、假体周围骨折、假体松动等并发症.Neer评分显示优良率84％,患者均能完成日常活动,患者主观满意度为76％.结论 通过严格把握手术适应证,掌握手术时机及操作要点,配合术后积极的功能康复训练,人工肱骨头置换术是治疗老年肱骨近端复杂骨折较满意的方法.     

社区劳务工人牙周健康的循证口腔护理研究

目的:探讨循证口腔护理模式对劳务工人群牙周健康的干预作用。方法:选择口腔疾病劳务工患者60例,根据循证护理原则制定口腔健康教育方案。分别于干预前及干预后6个月采用自行设计问卷调查其口腔健康知识知晓率和保健行为正确率,于干预前和干预后第1、3、6个月测定患者口腔菌斑指数。结果:干预后患者各项口腔知识知晓率和口腔保健行为正确率均较干预前明显提高(P <0.01);干预后第1、3、6个月,患者口腔菌斑指数均明显低于干预前(P <0.01)。结论:循证口腔护理能够有效提高社区劳务工口腔保健知识,改善口腔保健行为,降低菌斑指数,有助口腔疾病预防和牙周保健,值得推广。     

Nanomaterials for Inner Ear Diseases: Challenges,Limitations and Opportunities

The inner ear is located deep in the temporal bone and has a complex anatomy. It is difficult to observe and obtain pathological tissues directly. Therefore, the diagnosis and treatment of inner ear diseases have always been a major clinical problem. The onset of inner ear disease can be accompanied by symptoms such as hearing loss, dizziness and tinnitus, which seriously affect people’s lives. Nanoparticles have the characteristics of small size, high bioavailability and strong plasticity. With the development of related research on nanoparticles in inner ear diseases, nanoparticles have gradually become a research hotspot in inner ear diseases. This review briefly summarizes the research progress, opportunities and challenges of the application of nanoparticles in inner ear diseases.