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91.
92.
目的 :评估 5 %次氯酸钠 (NaOCl)溶液和饱和氢氧化钙 [Ca(OH) 2 ]溶液对牙本质弹性模量和挠曲强度的影响 ,以进一步了解根管治疗过程中药物对牙齿机械性能的影响。方法 :取新鲜拔除的完整前磨牙制成标准规格牙本质条 ,经 5 %NaOCl和饱和Ca(OH) 2 溶液处理 ,三点加荷系统测定其弹性模量和挠曲强度。结果 :5 %NaOCl使牙本质弹性模量和挠曲强度显著降低 ;饱和Ca(OH) 2 溶液使牙本质挠曲强度显著降低 ,对弹性模量无显著影响 ;5 %NaOCl处理后再用饱和Ca(OH) 2 溶液处理对牙本质弹性模量和挠曲强度无进一步影响。结论 :5 %NaOCl和饱和Ca(OH) 2 溶液对牙本质的机械性能有一定影响 相似文献
93.
超声洁治和局部用甲硝唑治疗轻、中度种植体周围炎 总被引:17,自引:0,他引:17
目的:评价用碳纤维工作头的超声洁牙机和25%甲硝唑凝胶治疗种植体周围炎的疗效。方法:将27颗患轻中度种植体周围炎的种植牙随机分为洁牙机治疗组和甲硝唑治疗组,在基线、1、2、6和12周时检查种植体的临床和生物学指标。结果: 两种治疗方法均可使菌斑指数、龈沟出血指数、龋下微生物的酶活性检查等指标改善。治疗期间未发现任何不良反应。结论;碳纤维头超声洁治和局部用25%甲硝唑凝胶是治疗牙种植体周围炎的安全有效的方法。 相似文献
94.
目的为了查清蓬莱地区居民口腔健康状况,为制订预防计划提供基线资料,为口腔保健措施及口腔健康教育的监测与效果提供依据。方法采用分层,等比整群随机抽样的方法,所采用的诊断标准为第二次全国口腔健康流行病学调查的标准。结果患龋率分别为:5岁组63.1%,12岁组28.6%,15岁组31.8%,18岁组43.6%,35~44岁组41.3%,65~74岁组61.8%。结论本次调查发现:①不同年龄组居民患龋率有明显差异。②本地区居民患龋率,龋均与第二次全国流行病学调查上海地区调查结果相比较低 相似文献
95.
The relationship of gingival crevicular fluid short chain carboxylic acid concentration to gingival inflammation 总被引:2,自引:0,他引:2
R. Niederman Y. Buyle-Bodin B.-Y. Lu C. Naleway P. Robinson R. Kent 《Journal of clinical periodontology》1996,23(8):743-749
Abstract Short-chain carboxylic acids (SCCA; C≤5: e.g., lactic acid, propionic acid, butyric acid) are metabolic by-products of bacterial metabolism which accumulate in the gingival crevice, and exhibit significant biological activity, including the ability to alter gene expression. It has been hypothesized that among the activities of SCCAs are their ability to contribute to gingival inflammation. This concept complements the notion that specific periodontal pathogens are the causative agents of gingival inflammation. To begin testing these 2 hypotheses, we examined the relationship between SCCA concentrations, specific putative periodontal pathogens, and gingival inflammation in medically healthy periodontally diseased subjects. We reasoned that if SCCAs and/or specific periodontal pathogens were causative gingival inflammatory agents, gingival inflammation should increase with increasing concentration of the inflammatory mediator. We also recognized that other clinical variables needed to be controlled for, and an objective quantitative assessment of gingival inflammation used. To accomplish these tasks, sites within subjects were stratified by location and pocket depth, and the following quantified: bacteria] presence; SCCA concentration: and gingival inflammation. The results indicated that gingival inflammation directly and significantly correlated with SCCA concentrations in the maxillary and mandibular molars, incisors and canines (all r≥0.47; all p≤ 0.015; too few bicuspids were available for complete analysis). The relationship between gingival inflammation and SCCA concentration was best described by a natural log relationship. Gingival inflammation did not, however, correlate positively with either the total number of specific putative periodontal pathogens, or the sum of subsets of these pathogens (?0.31 ≤r≤ 0.39; 0.08 ≤p 0.75) for any of the locations. Finally, the SCCA concentration did not correlate with the level of individual or groups of pathogens. These data, together with historical work and other preliminary data, support the hypothesis that SCCA, rather than specific putative periodontal pathogens, may be a causative agent in gingival inflammation. This work may, in part, begin to explain the apparent lack of a direct relationship between current gingival inflammation and the prediction of bacterially mediated periodontal attachment loss. 相似文献
96.
龈下残根修复前正畸治疗五例 总被引:7,自引:0,他引:7
目的 对损坏至龈缘下 1 5~ 3 5mm的前牙牙根在修复前行正畸牵引 ,当损坏平齐龈缘时再桩冠修复的方法进行探讨。方法 3例外伤、2例根面龋的患者 ,共 6个牙根接受完善根管治疗 ,修复前正畸暴露损坏 ,电刀修整牙龈 ,然后桩冠修复。结果 5例患者在修复后均取得了较满意的效果。结论 若前牙牙根损坏位于龈下釉牙骨质交界处 ,在修复前进行正畸治疗 ,既可保留残根 ,又可制作出有较好功能和美观效果的修复体 相似文献
97.
目的建立重庆市正常牙合青少年牙颌模型牙列指数的正常值,为正畸临床提供依据.方法选取重庆市正常牙合青少年牙颌模型92付(男45付,女47付),测量牙冠宽度、牙弓宽度,计算Bolton指数和Pont指数,对测量结果进行统计分析并与国内外相关资料进行对比研究,对Bolton指数和Pont指数的临床应用价值进行评价.结果Bolton指数和Pont指数存在种族和地区差异,结论Bolton指数和Pont指数在正畸临床中均有一定的应用价值,临床上应参照本民族和地区的标准. 相似文献
98.
Analysis of the Streptomyces coelicolor sigE gene reveals the existence of a subfamily of eubacterial RNA polymerase sigma factors involved in the regulation of extracytoplasmic functions. 总被引:18,自引:1,他引:17 下载免费PDF全文
99.
100.
The purpose of the present study was to determine the reliability of several selected signs of trauma from occlusion and their relations with severity of periodontitis. 32 moderate to advanced chronic periodontitis patients participated in the study. All teeth present were evaluated for various abnormal occlusal contacts, signs of trauma from occlusion, and the severity of periodontitis. Standardized periapical radiographs were also taken for each tooth. The results demonstrated that: (1) no significant difference occurred in probing pocket depth (PD), clinical attachment loss (AL), or percentage of alveolar bone height (BH) between teeth with and without various abnormal occlusal contacts, i.e., premature contacts in centric relation occlusion, non-working contacts in lateral excursions, premature contacts of anterior teeth or posterior protrusive tooth contacts; (2) teeth with either significant mobility, functional mobility, or radiographically widened periodontal ligament space (PDLS) had deeper PD, more AL and lower BH than teeth without these signs, while teeth with pronounced wear or radiographically thickened lamina dura had less AL than teeth without these findings; (3) 2 combined indices, i.e., the trauma from occlusion index (TOI) and the adaptability index (AI), were proposed for the identification of occlusal trauma and the response of periodontium to excessive biting forces in heavy function, respectively; TOI-positive teeth exhibit deeper PD, more AL and less osseous support than TOI-negative teeth; however, AI-positive teeth had less AL and more osseous support than AI-negative teeth; (4) with identical attachment level, TOI-positive teeth had less osseous support than TOI-negative teeth while the magnitude of difference became greater with an increase of attachment loss. 相似文献