Clinical, microbiological and immunological profile of healthy, gingivitis and putative active periodontal subjects

Thirteen periodontally healthy subjects were monitored clinically for 6–12 months. Clinical measurements at 6-weekly intervals included duplicate PD measurements, presence of plaque, redness, and bleeding on probing. Baseline measurements consisted of 2 visits I wk apart. Microbial samples were taken from 11 of the subjects who had completed at least 8 months of monitoring. Levels of serum antibodies to 12 periodontal species were determined from 10 subjects. Standard deviations of replicate PD measurements, computed for each subject, ranged from 0.2–0.3 mm over the monitoring period. Plaque and redness increased during monitoring, and showed a weak association with PD change. Baseline and follow-up distributions of PD changes indicated that changes of > 1.5 mm could reasonably be considered to represent active sites. Five subjects demonstrated at least 1 site deepening by 1.5 mm over the period monitored, and these were considered putative active subjects. Sites from 2 subjects showed PD increases in the 6 wk just before sampling, and these were considered to represent active sites. Species associated with putative active subjects included Actinomyces naeslundii, Veillonella parvula, Selenomonas noxia and Prevotella nigrescens. Streptococcus sanguis , S. gordonii and Peptostreptococcus micros were associated with inactive subjects. S. gordonii and S. oralis were associated with health, whereas P. nigrescens was associated with gingivitis. Elevated serum antibodies were detected to A. actinomycetemcomitans in 4 subjects. The predominant microbiota of putative active subjects included some species previously associated with gingivitis, and some species previously associated with progressing periodontitis.     

Mandibular complete denture impressions with fluid wax or polysulfide rubber: A comparative study

Some authors have stated that wax cannot be used to make impressions for complete dentures, while others have found that wax has some advantages over elastomeric impression materials. The purpose of this study was to compare mandibular impressions made with a fluid wax to those made with light-body polysulfide rubber. Fifteen maxillary and mandibular complete dentures were made using fluid wax as a final impression material. For comparison, 15 maxillary and mandibular complete dentures were made using light-body polysulfide rubber. The number of adjustments required over 1 year was recorded. No statistical difference in adjustments was noted between the two groups.     

喙突过长致开口受限的临床观察

目的报道喙突过长引起下颌运动受限、开口困难的病例资料，供临床工作借鉴。方法报道7例喙突过长致开口困难病例的临床、X线表现及治疗方法。结果曲面断层、华特位片可较好的显示突喙突过长，但往往不为临床医师所认识。本资料6例经手术切除过长的喙突后，开口度均恢复正常。结论喙突过长致开口困难较少见，应在开口困难的鉴别中予以注意。     

Prevalence of Nontraditional Dental Hygiene Practice

There is little knowledge of the number or the work characteristics of dental hygienists outside the private-practice setting. This survey was conducted to determine the percentage of hygienists practicing in nontraditional (nonprivate-practice) settings and the types of settings in which they are employed. Mail questionnaires were returned from a total of 21,847 (56.9%) of the hygienists in the survey sample. The percentage of active hygienists practicing in nontraditional settings was 11.8. Dental or dental hygiene schools, and government and nongovernment-supported clinics were the most frequent nontraditional practice settings. State supervision requirements were found to be associated significantly with the prevalence of nontraditional hygiene practice.     

Dimensional Accuracy of 7 Die Materials

PURPOSE: The purpose of this study was to compare the linear dimensional accuracy and the handling characteristics of 7 die materials. MATERIALS AND METHODS: A master die analogous to a complete veneer crown preparation was machined from medical grade stainless steel, and 3 measurements (1: vertical; 2 and 3: horizontal) were made from 3 scribed reference lines. Individual polyvinylsiloxane impressions were made (n = 10) for each of the specimens. The fabricated dies were measured (50x) to the nearest 0.0001 mm. Data were subject to ANOVA/Duncan tests at significance level 0.05 and pairwise comparisons. RESULTS: Type IV resin-impregnated dental stone and copper-plated dies most closely approximated the dimensions of the master die, and were not significantly different from each other in any of the pairwise comparisons. Conventional Types IV and V dental stone dies exhibited setting expansion within the range appropriate for gypsum. Epoxy resin die materials demonstrated shrinkage comparable to the expansion of the Types IV and V dies. Polyurethane dies displayed a combination of linear expansion and shrinkage. Bis-acryl composite resin dies had excessive shrinkage. CONCLUSIONS: Type IV resin-impregnated dental stone and copper-plated dies were more dimensionally accurate than the other die materials tested.     

右下颌支异位甲状腺癌1例报告

颌面部异位甲状腺癌临床罕见，有关报道颌面部异位甲状腺出现癌变常见的部位为下颌下、颏下及舌骨上下，但未见下颌支异位甲状腺癌的报道，作者报告1例右下颌支异位甲状腺癌病例，并对其临床及病理特征进行了讨论。     

硬衬材料中甲基丙烯酸酯单体释放的实验研究

目的 测定两种硬衬材料聚合后丙烯酸酯单体的释放量和趋势.方法 采用顶空固相微萃取气相色谱法测定两种常用的硬衬材料聚合后不同时段丙烯酸酯单体释放量.结果 两种硬衬材料的丙烯酸酯单体在10 min时释放量即达到释放总量的60%, 30 min时趋于稳定.在30 min时德山rebaseⅡ型丙烯酸酯单体释放量为0.003 9 mg/g,YJ-F自凝仿生义齿基托树脂为0.509 mg/g.结论 硬衬材料聚合后丙烯酸酯单体的释放随时间增加而逐渐下降,在30 min后趋于稳定.     

不同年龄组大鼠正畸力作用下龈沟液中基质金属蛋白酶的表达

目的:观察2个年龄组大鼠牙受正畸力后龈沟液中基质金属蛋白酶-1(matrix metalloproteinase-1,MMP-1)和基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)含量的变化.方法:选择6周龄和12周龄雌性Wistar大鼠各20只,采用粘结剂联合磨沟周位法在上颌安装正畸加力装置,牵引一侧上颌第一磨牙向近中,另一侧作为对照侧.每周提取大鼠实验牙及对照牙的龈沟液,应用SDS-PAGE、Western印迹和Gel-Doc凝胶成像系统定量检测龈沟液中MMP-1与MMP-9含量的改变.采用SPSS11.0软件包对实验各周龈沟液中MMP-1和MMP-9的含量进行方差分析.结果:6周龄组大鼠和12周龄组大鼠龈沟液中MMP-1及MMP-9含量的基础水平以及在加力第1周时的水平无统计学差异(P＞0.05).但12周龄组比6周龄组稍高.加力早期,12周龄组大鼠MMPs含量增长速度快于6周龄组;后期,12周龄组大鼠较6周龄组大鼠的MMPs含量下降速度慢.结论:12周龄大鼠受正畸力后,龈沟液中MMPs的表达较6周龄组高,12周龄大鼠较6周龄大鼠的正畸牙根吸收可能更严重.     

髁突骨折55例治疗体会

目的:探讨髁突骨折的治疗方法。方法:回顾性分析55例髁突骨折患者的资料,其中非手术治疗(保守治疗)40人,手术治疗15人,经随访1～5年,观察髁突骨折后成角和恢复情况与远期临床疗效的关系。结果:行保守和手术治疗者的平均髁突骨折移位角度分别为27°和56°,平均年龄分别为23岁和36岁。结论:根据髁突骨折移位角度和年龄来选择保守治疗或手术治疗,其远期效果较好。