外部激励对上颌前牙振动频率的影响

目的:测量不同外部激励下健康上颌前牙的振动频率,分析外部激励大小对上颌前牙牙齿振动频率的影响,为上颌前牙牙齿振动频率的测定提供校正曲线。方法:运用牙齿振动频率测试系统对临床20名志愿者的50颗健康上颌前牙进行不同外部激励下牙齿振动频率的测定,分析外部激励大小与上颌前牙振动频率的相关关系。结果:在不超过20 N的可耐受外部激励下,正常上颌前牙的振动频率介于580 Hz～830 Hz之间,消除加速度传感器附加质量影响后振动频率为632 Hz～904 Hz。统计分析得出,在可耐受外部激励范围内,上颌前牙振动频率与外激励呈显著正相关(r=0.944,P<0.01)。随着外部激励的增大,上颌前牙的振动频率呈线性增大趋势。结论:振动频率与外激励的关系曲线可以作为上颌前牙振动频率测定后的校正曲线。校正后的牙齿振动频率可以作为反映牙周组织健康状况的参考指标。     

有限元模拟牙周膜组织、牙齿振动频率和牙的动度的关系

目的:分析动态有限元模型中正常前牙牙周附着水平与其固有振动频率和牙齿动度的关系,以及承担咬合力后受力状况,为定量描述牙周附着水平和牙齿动度等牙周组织的生理状况提供理论依据。方法:在上颌前牙三维结构基础上,构建反映牙周附着水平和牙周组织弹性特征的动态三维有限元模型,对牙周附着水平、牙齿固有振动频率和牙齿动度的相互关系以及咬合力作用下应力传递过程进行动力学分析。结果:牙周健康上颌前牙振动是由多阶振动所构成,前四阶振动是其主要的振动形式,振动频率为1516.32、1761.44、2214.82、3243.98Hz,牙齿不同方向的动度与牙齿在该方向的振动频率与振型相关。结论:牙齿的动度可通过不同方向的振动频率及其振型定量表达,结合牙齿的动度、牙周附着水平和牙周组织力学特征进行动力学分析,能准确描述出牙齿和牙周组织的生理状况以及在行使功能过程中的生物学效应。     

前牙牙周附着水平与牙齿振动频率的有限元分析

目的：采用动态有限元法分析前牙牙周附着水平与牙齿固有振动频率和动度的关系，为定量描述牙周附着水平和牙齿动度等牙周组织的生理状况提供理论依据。方法：在上前牙三维结构基础上，构建反映牙周附着水平和牙周组织弹性特征的动态三维有限元模型，对牙周附着水平、牙齿固有振动频率和牙齿动度的相互关系进行动力学分析。结果：前牙振动是由多阶振动所构成，前4阶振动为主要的振动形式，与临床牙齿动度方向一致。随着牙槽骨的吸收和牙周附着水平的降低，前4阶振动频率逐渐降低。牙齿不同方向的动度与牙齿在该方向的振动频率与振型相关。结论：牙周附着水平与振动频率有明确的相关关系，通过牙齿振动频率的变化可以表达出牙周附着水平的变化，并且与牙齿动度建立相关关系，牙齿动度可以通过不同方向的振动频率和振型定量表达。     

后牙牙周附着与牙齿振动频率和动度的有限元分析

目的分析上颌第一磨牙牙周附着水平与牙齿固有振动频率的关系,为定量描述牙周附着水平和牙齿动度等牙周组织的生理、病理状况提供理论依据。方法采用CT图像和3D-doctor图像成型软件对上颌后牙进行三维重建,在此基础上构建反映牙周附着水平和牙周组织弹性特征的动态三维有限元模型,对牙周附着水平与牙齿固有振动频率和动度的相互关系进行动力学分析。结果上颌第一磨牙振动由多阶振动所构成,前四阶振动为主要的振动形式,振型方向与临床常见的牙齿动度方向基本一致。随着牙槽骨的吸收和牙周附着水平的降低,前四阶振动频率逐渐降低,下降趋势与牙周附着水平相关。结论牙周附着水平与振动频率相关,通过牙齿振动频率可以描述出牙周附着水平的变化,牙周附着水平不同牙齿动度可以通过不同方向的振动频率和振型定量表达。     

无锡市老年人牙周健康状况调查分析

目的:了解无锡市老年人牙周健康状况,为牙周疾病防治提供参考.方法:选择无锡市1156名65～74岁的老年人为调查对象,应用简化口腔卫生指数、牙龈指数、探诊出血、牙周袋探诊深度、临床牙周附着丧失、松动牙数及牙缺失数等,评价牙周健康状况.应用SPSS12.0软件包对数据进行t检验和x2检验.结果:无锡市老年人简化口腔卫生指数(OHI-S)为3.16±1.48,牙龈指数(GI)为1.33+0.54;牙龈探诊出血、牙周袋深度及牙周附着丧失等牙周健康状况未表现出显著的城乡差异.结论:无锡市老年人牙周健康状况不佳,应注重牙周病预防,普及和加强口腔健康教育.     

替牙期骨性Ⅲ类患者上前牙牙槽骨形态及其影响因素

目的 评估替牙期骨性Ⅲ类患者上前牙区牙槽骨形态，并探讨其影响因素。方法 选取替牙期骨性Ⅲ类患者48例，基于治疗前的锥体束CT(CBCT)，测量上颌中切牙和侧切牙唇舌侧的牙槽骨厚度和高度，测量牙齿长度、前牙倾斜度、下颌平面角。结果 上颌中切牙舌侧牙槽骨厚度为(3.34±1.33)mm，上颌中切牙唇侧牙槽骨厚度为(1.24±0.51)mm，上颌中切牙舌侧牙槽嵴顶距釉牙骨质距离(1.30±0.89)mm，上颌侧切牙唇侧牙槽嵴顶距釉牙骨质距离(1.68±0.88)mm。上中切牙舌侧牙槽骨厚度、唇侧牙槽骨高度与切牙唇倾度负相关，上切牙唇侧牙槽骨厚度与牙齿长度和下颌平面角负相关。结论 替牙期骨性Ⅲ类患者上切牙唇侧牙槽骨较薄，附着高度较低，舌侧牙槽骨较厚、附着高度较高。上切牙牙槽骨形态与切牙唇倾度、牙齿长度、下颌平面角均有相关性。     

宁波某石化企业员工牙周健康状况调查分析

目的 了解宁波某石化企业员工的牙周健康状况,为企业提供口腔职业保护信息。方法 根据第3次全国口腔健康流行病学调查所采用的《口腔健康调查基本方法》（世界卫生组织制定的第4版）的调查方法和标准, 2008年3—9月,对宁波某石化企业2 108名抽样员工,进行检查牙周状况, 结果 ①2 108名抽样员工的牙周健康率为20.5 %,牙周炎患病率52.3%［95% CI:（52.3±2.1）%］;牙龈出血检出率为61.5%,人均患牙（1.20±1.93）颗;牙结石检出率为64.2%,人均患牙（5.96±7.80）颗;牙周袋检出率为26.2%,人均患牙（0.94±2.37）颗;牙周附着丧失≥4 mm者的检出率为51.0%,人均患牙（5.63±6.88）颗。② 65～74岁组的员工牙周附着丧失检出率为76.9%,高出全国东部的73.6%。结论 宁波石化企业员工牙周健康状况均好于全国东部同类地区的居民;35～59岁组的男性员工应成为牙周附着丧失的重点监控对象,加强口腔健康宣教和改进不良刷牙方式。     

成年人牙周附着状况十年纵向研究

目的 观察口腔卫生条件较差的我国农村地区成年人牙周病的自然发展过程,分析牙周病进展速率与发达国家地区人群的区别。方法 在1984年对587名受检者进行的口腔状况调查的基础上,1994年由相同的检查人员随访复查了440人,其中398人仍有牙列,对其所有存留牙的牙齿松动度及牙周附着丧失、牙周袋深度等情况作了复查,分析牙周病的进展特点。结果 各年龄组受检者在10年后复查时,均有平均2mm以上的牙周附着丧失。下颌切牙和上颌磨牙的牙周病进展速率较其他牙齿为重。成年人的平均牙周附着丧失率在各年龄组之间差异无显著性。受检人群与其他口腔卫生习惯和口腔保健条件均较好的发达国家人群相比,牙周附着丧失情况基本相似。结论 与发达国家人群相比,牙周附着状况未显著不同;各年龄组相互之间,牙周病发展速率亦未见显著不同。提示人类牙周病发展可能是人类自身内在因素起决定性作用。     

社区退休人员牙周健康状况调查及影响因素分析

目的 了解社区退休人员的牙周健康状况及影响因素,为社区医院制定针对本社区老年人的口腔预防、保健和治疗计划提供参考.方法 采用随机抽样的方法,选择240位在社区医院进行年度健康体检的退休人员作为调查对象进行问卷调查和全口牙周检查,并进行统计学分析.结果 所有调查对象都有不同程度的牙周附着丧失,全口平均附着丧失为(2.17±1.28) mm,全口平均探诊深度为(2.36±0.42) mm.刷牙习惯的不同显著影响探诊深度(P＜0.05).性别、年龄和吸烟习惯对附着丧失有显著影响(P＜0.05).结论 以牙周附着丧失为标准,所有调查对象均有牙周组织疾病;刷牙习惯和吸烟习惯是影响牙周健康的因素.     

慢性牙周炎栖牙密螺旋体和牙周袋内硫化物水平的相关性研究

目的 研究慢性牙周炎病人牙周袋内栖牙密螺旋体和牙周袋内硫化物水平的关系。方法 临床上选取17例诊断为慢性牙周炎的病人,采用金刚探针/牙周诊断仪检测牙周袋内硫化物水平,记录牙周袋探诊深度、临床附着丧失以及探诊出血相关牙周指标。同时,采用16S rRNA PCR检测相同位点的栖牙密螺旋体。结果 慢性牙周炎病人栖牙密螺旋体检出率为88.2%,硫化物阳性位点和硫化物阴性位点中栖牙密螺旋体的检出率分别为68.5%和43.2%。硫化物阳性位点与阴性位点中牙周附着丧失（clinical attachment loss, CAL）平均值分别为（2.84±2.33）mm和（1.83±1.60）mm,两者差异有统计学意义（P<0.01）。硫化物阳性位点与阴性位点牙周探诊深度（probing depth, PD）平均值分别为（4.20±1.57）mm和（3.83±1.30）mm,两者差异无统计学意义(P＞0.05)。硫化物阳性位点中牙周探诊出血（bleeding on probing, BOP）阳性检出为率92.5%,大于硫化物阴性位点（75.8%）,两者差异有统计学意义（P<0.01）。结论 慢性牙周炎病人牙周袋内的硫化物水平能反映牙周栖牙密螺旋体分布情况,与牙周附着丧失存在相关性。     

Relationship of cigarette smoking to attachment level profiles

OBJECTIVES: The present investigation examined clinical features of periodontal disease and patterns of attachment loss in adult periodontitis subjects who were current, past or never smokers. MATERIAL AND METHODS: 289 adult periodontitis subjects ranging in age from 20-86 years with at least 20 teeth and at least 4 sites with pocket depth and/or attachment level >4 mm were recruited. Smoking history was obtained using a questionnaire. Measures of plaque accumulation, overt gingivitis, bleeding on probing, suppuration, probing pocket depth and probing attachment level were taken at 6 sites per tooth at all teeth excluding 3rd molars at a baseline visit. Subjects were subset according to smoking history into never, past and current smokers and for certain analyses into age categories <41, 41-49, >49. Uni- and multi-variate analyses examined associations between smoking category, age and clinical parameters. RESULTS: Current smokers had significantly more attachment loss, missing teeth, deeper pockets and fewer sites exhibiting bleeding on probing than past or never smokers. Current smokers had greater attachment loss than past or never smokers whether the subjects had mild, moderate or severe initial attachment loss. Increasing age and smoking status were independently significantly related to mean attachment level and the effect of these parameters was additive. Mean attachment level in non smokers <41 years and current smokers >49 years was 2.49 and 4.10 mm respectively. Stepwise multiple linear regression indicated that age, pack years and being a current smoker were strongly associated with mean attachment level. Full mouth attachment level profiles indicated that smokers had more attachment loss than never smokers particularly at maxillary lingual sites and at lower anterior teeth. CONCLUSIONS: In accord with other studies, smokers had evidence of more severe periodontal disease than past or never smokers. At all levels of mean attachment loss, smokers exhibited more disease than never smokers. Difference in mean attachment level between smokers and never smokers at individual sites was not uniform. Significantly more loss was observed at maxillary lingual sites and lower anterior teeth suggesting the possibility of a local effect of cigarette smoking.     

A possible influence of gingival dimensions on attachment loss and gingival recession following placement of artificial crowns

The aim of the present study was to determine the influence of gingival dimensions on the development of gingival recession following placement of artificial crowns. The study population consisted of 11 periodontally healthy patients in whom 44 maxillary anterior teeth and/or premolars had to be crowned. A total of 36 teeth (82%) had, after crown placement, a mean intracrevicular crown margin of 0.57 +/- 0.47 mm. Thirty-nine teeth without restorations served as controls. Immediately after incorporation, as well as after 3, 6, 9, and 12 months, periodontal examinations were carried out. Gingival thickness was determined sonometrically and averaged 1.25 +/- 0.40 mm. Mean periodontal probing depth was 1.80 +/- 0.54 mm. Twelve months later, crowned teeth had experienced a mean attachment loss of 0.17 +/- 0.99 mm as compared to an attachment gain of 0.18 +/- 0.46 mm at control teeth. At test teeth, the gingival margin had receded a mean of 0.43 +/- 0.74 mm. In multivariate analyses considering the correlated structure of the data employing generalized estimating equation methods, crown placement was identified as a major factor for attachment loss and development of gingival recession. In addition, a shallow probing depth and narrow band of gingiva negatively influenced the level of periodontal attachment. The present results point to the importance of a more detailed periodontal diagnosis of the dentogingival region before placement of artificial crowns.     

Clinical attachment loss produced by curettes and periodontal files

The aim of this study was to clinically evaluate the effect of immediate trauma from instrumentation after scaling and root planing with different instruments. Ten subjects with moderate chronic periodontitis, presenting probing depths of 3.5-6.5mm on anterior teeth, maxillary and/or mandibular, were selected. Teeth were randomly assigned to one of the following groups: PF group - scaled and planed with Hirschfeld periodontal files; CC group - scaled and planed with Gracey conventional curettes. The selected teeth were probed with a computerised electronic probe, guided by an occlusal stent and subjected to scaling and root planing. Immediately following instrumentation, teeth were probed again. The difference between relative attachment level (RAL) immediately before and after instrumentation was considered as trauma from instrumentation. Intra-group analysis revealed statistically significant differences between RAL immediately before and after instrumentation in both groups (1.28 +/- 1.13 for PF group; and 0.83 +/- 0.41 for CC group - p<0.05). However, inter-group analysis did not show statistically significant difference in trauma from instrumentation caused by the different instruments (p=0.063). Within the limits of this study, it was concluded that root instrumentation causes a mean immediate attachment loss of 1.06mm, with no differences between instrumentation with periodontal curettes or periodontal files.     

In vivo and in vitro natural frequency analysis of periodontal conditions: an innovative method

BACKGROUND: When measuring periodontal disease, various types of equipment for making objective measurements of tooth mobility have been proposed. However, these devices and methodology are insufficient in terms of reliability. An innovative method using vibrational theories to assess the periodontal attachment level of natural teeth is presented in this study. METHODS: Modal testing technique, a non-destructive and time-saving method, was used for non-invasive and quantitative measurement of the natural frequencies of the upper central incisor in vivo and in vitro. A finite element model was established, and modal testing experiments were simulated to assess the relationship between bone level and teeth. RESULTS: The first dominant natural frequency of healthy human upper central incisors ranges from 710 Hz to 3,360 Hz, with an average of 1,701+/-679 Hz. Both in vitro experiment and finite element simulation showed that lowering of the attachment level causes a significant decrease in the natural frequencies, and a strong relationship (r = -0.99, P <0.01) was observed between the frequency and the bone level height. CONCLUSIONS: Our results suggested that natural frequency is an important parameter for assessing the periodontal condition and that the modal testing technique is a useful supplemental method for assessing the attachment conditions of the periodontium.     

Risk indicators for future clinical attachment loss in adult periodontitis. Tooth and site variables.

In an earlier report, we examined the relationship of patient-derived clinical and epidemiological variables to the risk for future clinical attachment loss (CAL) in chronic adult periodontitis. We determined that the extent of the patient's existing periodontal disease as measured by mean attachment loss (MAL) and the patient's age were the most important patient-derived risk indicators for CAL among those factors evaluated. In this study, we examined the tooth and site variables that were associated with CAL. Seventy-five patients with chronic adult periodontitis were followed for 6 months. Clinical data at baseline, including attachment level and probing depth, were obtained from six sites per tooth. The hazard rate for CAL at all sites was 2.0%, and 4.1% of teeth displayed at least one site with CAL. Mandibular and maxillary molars and maxillary premolars displayed the highest incidence of CAL (6.1%, 5.6%, 5.5%, respectively), while maxillary anterior teeth (1.8%) and mandibular premolar teeth (2.1%) demonstrated the lowest incidence. The greatest number of sites demonstrating CAL had an existing attachment level of 4 to 7 mm and a probing depth of less than or equal to 5 mm. When the data were converted to hazard rates, however, an increase in hazard rate was seen with increasing existing attachment loss or probing depth. When MAL was considered, patients with mild and moderate periodontitis demonstrated a relatively low incidence of CAL at sites with less than or equal to 7 mm of existing attachment loss. Patients with severe periodontitis exhibited greater hazard rates for sites with 0 to 3, 4 to 5 and 6 to 7 mm of existing attachment loss.(ABSTRACT TRUNCATED AT 250 WORDS)     

Association between cigarette smoking and the intraoral distribution of periodontal disease in Thai men over 50 years of age

Aim: This study aimed to investigate the effects of cigarette smoking on periodontal conditions in specific tooth regions of older Thai men. Methods: There were 272 current smokers, 714 former smokers, and 477 non‐smokers enrolled in the present study. Differences between groups in the mean probing depth or attachment loss were compared using ancova . The relationship between smoking exposure or cessation duration and periodontal conditions was examined using linear trend analysis. Results: Smokers had deeper pockets and attachment loss than non‐smokers. The greatest differences between smokers and non‐smokers were observed in the maxillary posterior palatal region, where current smokers had 0.88 mm greater attachment loss than non‐smokers, compared to 0.36–0.60 mm observed in other tooth regions. Among the current smokers, there was a trend towards an increase in attachment loss with increasing smoking exposure in the maxillary posterior regions. However, it was not statistically significant. Among the former smokers, a better periodontal condition was observed, depending on the length of time since smoking cessation; this was most pronounced in the maxillary posterior palatal region. Conclusions: The palatal site of maxillary posterior teeth was the area most affected by cigarette smoke. The results suggest a possible local effect of smoking in addition to its systemic effects.     

Prevalence of horizontal attachment loss in extracted teeth

Objective: Probing attachment level provides useful information on patterns of destruction of the periodontium. It is difficult to detect complex attachment loss in clinics. The purpose of this study was to estimate prevalence of vertical and horizontal attachment loss in extracted teeth. Material and Methods: We collected 10,212 extracted teeth from 130 dentists in Japan. After staining of periodontal membrane with erythrosine, linear loss of vertical and horizontal attachment was measured using a digital caliper. Results: Mean vertical attachment loss varied from 5.3 to 8.6 mm. Incisors had severe attachment loss at mesial sites. Specific local attachment loss at palatal sites was observed in maxillary premolars and molars as well as in mandibular canines and premolars. Horizontal attachment loss was observed in 23% of the teeth. Frequency of horizontal attachment loss of 2.1 mm was 6.4%. Conclusion: Severe attachment loss was observed on the palatal side of maxillary premolars. More than 1/3 of the maxillary first molars showed horizontal attachment loss. It may be impossible to debride 6.4% of teeth in cases of severe periodontitis because horizontal attachment loss may be deeper than the curette blade length.     

Comparison of results following three modalities of periodontal therapy related to tooth type and initial pocket depth

Abstract Results following three modalities of periodontal therapy (subgingival curettage, modified Widman flap surgery, and pocket elimination or reduction surgery) in 78 patients over 8 years were compared for variations in pocket depth and clinical attachment level related to tooth types (maxillary molars, mandibular molars, maxillary biscupids, mandibular biscupids, maxillary anterior teeth, mandibular anterior teeth). The analysis was based on a classification of three severity groups according to initial crevice or pocket depth (Class I, 1–3 mm; Class II, 4–6 mm; and Class III, 7–12 mm) and with patient's means of measurements being the experimental units for the statistical analysis. Reduction in pocket depth and gain of clinical attachment for pockets 4 mm or deeper occurred following all three methods of treatment, and was well sustained over 8 years. No one modality of treatment was consistently superior to any of the other two with regards to sustained reduction of pocket depth and gain of clinical attachment. Surgical pocket elimination or reduction did not enhance the prognosis for maintenance of periodontal support in either moderate or advanced periodontal lesions anywhere in the mouth compared with more conservative modalities of treatment. In spite of prophylaxis and instruction in home care every 3 months, there was a slight progressive loss of attachment over time in areas of shallow crevices (1–3 mm).