美学区天然基牙二次冠修复中预备体不良边缘的处理策略

天然基牙二次冠修复是固定修复的难点之一。天然基牙需要进行二次冠修复的原因包括美学因素、侵犯生物学宽度等。本文将围绕美学区天然基牙二次冠修复中预备体不良边缘如何进行修复-牙周治疗的处理策略进行探讨，梳理美学区天然基牙二次冠修复不良边缘处理的决策树。美学区天然基牙二次冠修复中预备体边缘是核心，总的治疗原则为在适宜的美学位置、适宜的生物学位置，形成清晰、光滑及连续的边缘形态。     

前牙美学区即刻种植即刻美学修复的临床观察

目的：探讨前牙关学区即刻种植即刻美学修复的临床特点及修复后的美学效果。方法：18例患者22枚m和Replace种植体前牙区即刻种植即刻临时冠修复,对种植体成功率及周围牙龈附着状况进行观察,6个月后永久冠修复。结果：1枚种植体在愈合期内脱落,其余种植体在修复后12个月时均有骨结合,临床效果良好。结论：前牙美学区即刻种植即刻美学修复时多因素可影响种植体的成功率及软组织美学效果,严格掌控适应证,才能获得理想的美学效果。     

上颌前牙区种植美学修复的临床探讨

目的：探讨上颌前牙区应用多种种植美学修复方法的临床效果。方法：68例上颌前牙缺失的患者行即刻或延期种植，采用软硬组织增量或临时冠诱导等方法进行美学修复，评估修复2年后的种植成功率和软组织美学。结果：种植修复2年后的成功率为97.4%，种植修复体近远中Jemt牙龈乳头指数Ⅱ级以上者为93.4%。结论：根据患者自身条件，综合采用多种美学修复方法可使上颌前牙区种植义齿修复达到较满意的临床效果。     

美学区临界小缺牙间隙种植修复的临床研究

目的探讨标准直径种植体修复美学区临界小缺牙间隙的临床效果。方法 7例上颌前牙区单牙缺失间隙约6.0 mm的成年患者,植入直径3.5 mm的根形螺纹种植体,骨整合后,临时冠塑形牙龈,择期永久修复。结果 7例患者美学效果满意,2年观察期内未见明显骨吸收,软组织水平稳定。结论美学区临界小间隙采用标准直径种植体修复,短期效果良好,远期效果有待进一步观察。     

美学区多牙连续缺失种植修复的印模制备方法

美学区种植修复时，准确转移修复体穿龈轮廓至终印模对实现最终美学效果至关重要。美学区单牙种植修复的个性化印模已广泛应用，然而连续多牙种植修复的个性化印模相对复杂。本文列举了美学区多单位种植修复的个性化印模方法。通过对比初印模缺失或具备两种临床情况，提出推荐分次印模分别转移种植体位置与复制穿龈轮廓的建议。     

现代口腔美学因素分析

随着患者需求的发展,口腔修复已由功能性修复转向口腔功能性美学修复。虽然国内的口腔医师已逐渐树立口腔美学观念,但由于颌面部组成复杂,其中美学区牙列与牙龈解剖结构微妙、口内结构与唇部的动态关系难以把握,正侧貌的参考线角较多,使得口腔美学的临床应用极为困难,口腔修复难以达到理想的美学效果。本文通过对颌面美学影响因素进行重点分类系统阐述,拓展口腔美学修复的临床应用。     

美学区种植修复的评价和临床程序

评价种植修复的临床效果包括种植修复体的长期骨结合和美学效果。近年来,伴随着美学种植原则的确立和美学种植修复技术的成熟,口腔种植进入一个新的历史阶段。本文将根据笔者的临床经验和文献资料,简要介绍目前已经明确的美学种植的定义、评价和风险因素,并以病例报告的形式向读者推荐美学区种植的临床程序,为读者的美学种植修复的临床实践提供帮助。     

牙龈瓷在红色美学修复中的应用技巧-附病例报告

目的：研究修复治疗中对于红色美学缺陷的修复技巧及修复效果。方法：通过使用牙龈瓷补偿前牙美学区软硬组织严重缺失的固定修复病例,结合有关临床和工艺制作的文献资料,对其修复设计方案、修复体设计以及制作过程进行讨论。结果：修复治疗效果得到患者及医生的一致满意。结论：对于红色美学缺陷的患者,有技巧地运用修复技术可以达到良好的美学修复效果。     

多学科联合治疗重度牙周炎导致的前牙连续缺失（附1例4年随访报告）

随着生活水平及口腔治疗技术的提高,上前牙美学区种植修复成为越来越多患者的选择。因重度牙周炎伴有错牙合畸形进而导致前牙美学区连续失牙是临床上十分棘手的难题,若同时存在缺牙区软硬组织缺损,采用种植修复将面临巨大挑战,要解决此类问题往往需要多学科联合治疗。文章展示了1例重度牙周炎病例的诊疗全过程,包括病情分析、多学科参与治疗设计、具体实施步骤和修复后效果等,为临床解决因重度牙周炎导致上前牙美学区连续失牙的种植修复问题提供了经验。     

上颌前牙区种植修复后龈乳头外形的影响因素

近年来随着种植技术的发展,人们对于美学效果的要求越来越高,特别足在上颌前牙区,对更多病人而言,美学效果和功能同等重要,软组织美学成为种植修复成功的必备条件。牙槽骨水平、种植体的位置、缺牙数目等都是影响美学效果的因素。而完整的龈乳头外形是为达到美学效果所不可或缺的。本文就上颌前牙区种植修复后龈乳头外形的影响因素作如下综述。     

不同经济水平地区口腔健康知识和健康行为的调查分析

目的研究社区居民的口腔健康知识认知和健康行为状况,为口腔预防保健工作的开展、口腔健康教育及促进提供理论依据。方法采用整群随机抽样的方法,对1 178名社区居民进行口腔健康知识认知和健康行为情况问卷调查。结果在刷牙次数、每次刷牙时间和牙刷更换频率方面经济欠发达地区均好于经济发达地区（P＆lt;0.05）。两类地区人群刷牙方法正确的仅占45.5%,刷牙水温选择正确的只占24.3%,77.2%的调查者无定期口腔健康检查习惯。在偏侧咀嚼习惯上,经济欠发达地区高于经济发达地区;在咬硬物习惯上,经济发达地区高于经济欠发达地区。对洁牙和窝沟封闭的认知度经济发达地区好于经济欠发达地区。经济发达地区居民多选择正规牙科医院,经济欠发达地区居民多选择小型牙科诊所;经济发达地区居民牙痛就医率高于经济欠发达地区（P＆lt;0.05）。结论社区居民对口腔健康认知度普遍较低,经济水平较高地区好于经济水平较低地区,因此口腔健康宣教有待加强,日常口腔保健行为有待改善。     

A quantitative study of the face in Down's syndrome.

The large number of persons with Down's syndrome among the group of physically and mentally retarded demands that continuing study be directed toward its causes and effects. Much conflicting data are reported in the literature concerning the facial and cranial effects of this syndrome. The cephalic proportions, in profile, of a group of male Caucasian trisomic Mongoloids were compared with the proportions of a control group of male Caucasians of similar age range. Using the areas of the midface, mandible, and endocranium obtained from cephlograms of the two groups, the following ratios were studied: (1) midfacial area/endocranial area (2) mandibular area/endocranial area, and (3) midfacial area/mandibular area. A significant degree of deficiency in midfacial area, mandibular area, and endocranial area was found in the Mongoloid group. In studying the facial proportions, we found that the Down's syndrome group's ratios were significantly smaller in all three areas. The magnitude of the deficiency in the Mongoloid midface, both in gross area and in relation to endocranial area, remained nearly constant with age. The ratio of midfacial area to mandibular area in Mongoloids was much more comparable to that of the normal group than the other two ratios studied. In both groups the ratio of the midfacial area to the mandibular area became smaller with age. The decrease was more rapid in the Down's syndrome group. The findings of this study imply that all areas of the face and skull are deficient in persons with Down's syndrome. The data point to the possibility that the characteristics of this syndrome and the deficiencies described are polygenic in origin. Also, contrary to the majority of reports in the literature, the mandible and the midface grow in approximately the same proportion in both study and control groups     

影响载荷下上颌半口义齿基托变形因素的三维有限元分析

目的:研究功能状态下上颌半口义齿基托边缘封闭区及中线区不同位点变形的方向、大小及其与牙尖斜度、腭穹窿形态的关系.方法:使用三维有限元法分别对牙尖斜度为0°、20°、30°的尖、平、凹型腭穹隆形态的上颌半口义齿进行加载,得出义齿基托磨光面各节点的三维变形方向及数值.结果:双侧后牙加载时基托颊侧边缘区发生背离支持组织变形,...     

桩核印模完整性的临床调查

目的：观察现阶段临床桩核印模的完整性,明确桩核印模出现缺损性缺陷的主要部位。方法：建立评价桩核印模完整性方法,将桩核印模分为桩核区、非桩核区、印模与托盘连接区,桩核区进一步细分为桩的根尖部、桩体部、牙本质肩领部、龈沟部。对156例临床桩核印模各区的完整性进行观察。结果：印模桩核区、非桩核区和连接区印模缺陷发生率依次为61.54%、45.79%、1.96%,桩核区印模缺陷的发生率显著高于其他区域（P〈0.01）;桩核区的根尖部、桩体部、牙本质肩领部、龈沟部印模缺陷发生率依次为36.54%、19.23%、0.64%、33.97%,桩核区印模的根尖部、龈沟部缺陷发生率显著高于桩体部和牙本质肩领部（P〈0.01）。结论：本组临床桩核印模存在较高比例的缺陷;气泡性缺损好发于桩核区印模的根尖部;龈沟部印模不清晰。     

The main occluding area in normal occlusion and mandibular prognathism

Objective:To clarify whether the concept of main occluding area, where hard food is initially crushed, exists in patients who have a jaw deformity.Materials and Methods:Nineteen subjects with normal occlusion, 18 patients with mandibular prognathism, and 11 patients with mandibular prognathism who had undergone orthognathic surgery participated in this study. The main occluding area was identified by clenching Temporary Stopping. The coincidence, location of the main occluding area, and distance from the first molars to main occluding area were examined.Results:High coincidence of the main occluding area was obtained in all groups, signifying that the main occluding area exists even in these patients. Mandibular main occluding area was located on the first molar in all groups. Maxillary main occluding area in subjects with normal occlusion was located on the first molar. However, it was located on the second premolar and first molar in patients with mandibular prognathism, and on the first and second molars in patients with mandibular prognathism who had undergone orthognathic surgery. There was a statistically significant difference in distance from the maxillary first molar to the main occluding area among groups, but there was no difference in the distance from the mandibular first molar among groups.Conclusion:The main occluding area is more stable on the mandibular first molar than the maxilla in all groups.     

Dental fluorosis in children in areas with fluoride-polluted air, high-fluoride water, and low-fluoride water as well as low-fluoride air: a study of deciduous and permanent teeth in the Shaanxi province, China

OBJECTIVE: The aim of the study was to assess dental fluorosis (DF) in the deciduous and permanent teeth of children in areas with high-F coal (area A) and high-F water (area C) compared to children from area B, with low-F water and coal. MATERIAL AND METHODS: 596 children were examined. DF was assessed by TF-score. F-content of indoor air, drinking water, coal, tea, rice, and maize was analyzed. RESULTS: F-content of air and coal ranged from 3.2 microg/m(3) and 25.8 mg/kg (area B), 3.8 microg/m(3) and 36.3 mg/kg (area C) to 56.8 microg/m(3) and 713.1 mg/kg (area A). Likewise, mean F-content of water ranged from approximately 0.50 mg/l (areas A and B) to 3.64 mg/l (area C). F-content of tea leaves was similar in all three areas. Maize and rice contained <5 mg F/kg. Prevalence of primary teeth with DF was 49.1%, 2.0%, and 66.8% in areas A, B, and C, respectively. Similarly, DF was found in 96.7% (area A), 19.6% (area B), and 94.4% (area C) of the permanent teeth. Severe fluorosis (TF > or = 5) was found in area A (47.0%) and area C (36.1%) (p<0.01). Early erupting teeth had slightly higher mean TF-scores in area A than in area C. CONCLUSIONS: DF was prevalent in both dentitions in areas A and C. Similarity in percentages of DF may indicate that indoor air with approximately 60 microg F/m(3) and drinking water with 3.6 mg F/L are similarly toxic to developing permanent teeth. The percentage of deciduous teeth with DF was significantly lower in area A compared to area C. Where low-F coal and low-F water were used (area B), approximately 20% of permanent teeth had DF, indicating a relatively low tolerance to fluoride in Chinese children brought up under the present living conditions.     

Electron microscopic study of periodontal tissues in the pressure side by intermittent forces

The intermittent forces (10g and 30g) were applied to the upper right first molars of mature Wistar rats to move them lingually for 1, 5 and 9 days with wire springs. The periodontal tissues in the pressure side were investigated light/electron-microscopically and cytochemically (localization of acid phosphatase activity). The periodontal tissues in the pressure side divided into the following three areas were observed. The area I: The area of hyalinized tissues. The area II: The area situated within 100 microns from the end of hyalinized tissues. The area III: The area situated within 100 microns from the border of area II. The following results were obtained. I Tooth movement Experimental teeth applied with 30 g were moved much more than those applied with 10g. II Light microscopic findings 1) The narrowness of the periodontal space in the area I was not observed remarkably on 1 and 5 day experiment of 10g and 1 day experiment of 30g, though hyalinized tissues had appeared in them. 2) Semi-hyalinized tissues observed in some parts of area II degenerated into hyalinized tissues during the experimental periods. 3) Direct resorption of alveolar bone by osteoclasts was seen initially in the area III on 5 day experiment of 10g and 1 day experiment of 30g. III Electron microscopic findings 1) The hyalinized tissues (area I) and semi-hyalinized tissues (some parts of area II) were characterized to contain only a few necrotic cells and cell debris. The localization of Acpase activity could not be seen in these cells and cell debris. 2) Fibroblasts in the area II and III showed various appearances; autophagy, heterophagy of collagen fibrils, fusion with other fibroblasts and cell degeneration. And the localization of Acpase-activity was observed remarkably in lysosomes, secondary lysosomes and Golgi apparatus. A few macrophages were observed in the area II and III, but the other inflammatory cells and foreign body giant cells could not be seen. 3) On the other hand, active and inactive osteoclasts were seen on the bone surface in both area II and area III.     

Accuracy of supported root ratio estimation from projected length and area using digital radiographs

BACKGROUND: The purpose of this study was to evaluate the accuracy of supported single-root surface ratio estimated from the length and projected area of the tooth, using digital dental radiographs. METHODS: Eight extracted, single-root teeth were three-dimensionally digitized using a contact technique for surface area measurement. The data were then processed using engineering application software and length, projection area, and true surface area of the root at a designated length were obtained. Based on these three measurements, the accuracy of the supported surface area ratio measurement at different lengths of the root was evaluated. RESULTS: The largest mean errors from linear and area estimation were 9.58% and -1.16%, respectively. The 95% confidence intervals were all positive, indicating that linear measurements overestimated supported ratio. T tests showed that linear estimations resulted in significant differences in all eight teeth and area estimations in five teeth. When analyzing the supported ratio of the alveolar bone receding from the cemento-enamel junction (CEJ) toward the apex of the root at each mm, linear estimation showed significant differences down to 8 mm, while area estimation showed significant differences only up to 2 mm. CONCLUSIONS: The results of this study indicate that a reliable estimate of the ratio of root surface area supported by alveolar bone cannot be determined from linear or area data. However, when the marginal bone destruction exceeds 2 mm from the CEJ, area estimation does not show a significant difference in the supported region. As demonstrated in this study, root surface ratio estimation function could be an advantage of digital dental x-ray systems in which projected root area is readily observed.     

Main occluding area in partially edentulous patients: changes before and after implant treatment

The 'main occluding area', the location where food crushing occurs during the first stroke of mastication, is reported to be an important concept; however, it is currently limited to findings in individuals with normal dentition. The purpose of this study was to assess the changes in the location, area and bite force of the main occluding area before and after implant treatments. We enrolled 50 partially edentulous and 22 normally dentate subjects. To identify the location of the main occluding area, each subject was instructed to freely bite once on a dental stopping using the partially edentulous side or the normally dentate area. The location, occluding contact area and bite force of the main occluding area before and after the implant treatments were analysed. The main occluding area was located at a reproducible location in the partially edentulous and normally dentate subjects. This location was principally the first molar region, and for the partially edentulous patients with missing teeth in the molar regions, it moved from the premolar region to the first molar region after treatment. The occluding contact area and bite force for the main occluding area increased (P < 0·05) after the implant treatment in the partially edentulous patients with missing teeth in the molar regions. These results suggest that the main occluding area can be restored to the first molar region after implant treatment and may be an important factor in the assessment of prosthodontic treatment.     

Measurement of fissure sealant surface area by computer

The amount of occlusal surface area covered when fissure sealant is applied to a tooth has not been previously reported. This study measured the occlusal surface area and sealant surface area using a computer-driven profilometric system. Twenty-two recently erupted, caries-free premolars were used. The mean occlusal area for all premolars was 34.34 mm2 +/- 4.42 mm2. The mean surface area of applied sealant for all teeth was 8.06 mm2 +/- 1.67 mm2, and the mean percentage of occlusal surface area covered by sealant was 23.97% +/- 5.02%. The occlusal surface area of mandibular first premolars was significantly smaller than that of the other premolar groups. However, this difference was not reflected in the area of sealant applied to premolars or in the percentage of occlusal surface covered by sealant. Mandibular first premolars required the same amount of coverage as the other tooth groups.