氟保护漆预防牙釉质脱矿的效果评价

背景:近年来在正畸治疗中产生牙釉质脱矿的副作用受到了越来越多的关注.尽管采取了各种方法和试剂,治疗效果尚不统一.目的:观察在牙齿正畸治疗过程中氟保护漆对牙釉质脱矿的保护效果.设计、时间及地点:对比观察,病例来自2006-01/2009-01解放军济南军区青岛第二疗养院口腔中心正畸科.对象:入选固定矫治患者132例(856颗牙),男56例,女76例,年龄7～18岁,平均年龄10.5岁.所有参与者牙体硬组织均发育良好,无四环素牙、氟斑牙、无牙体充填物,对治疗签订知情同意书,接受牙面处理和定期复查.方法:将实验对象随机分成实验组和对照组.实验组的牙齿安装粘托槽是使用氟保护漆,并每3个月重涂1层,而对照组和实验组操作基本相同,只是不使用氟保护漆.正畸治疗结束后,拆除矫治装置,对所有牙齿进行清洁抛光,观察记录数据.主要观察指标:两组正畸治疗后牙釉质脱矿的检出率.结果:实验组牙釉质脱矿发生率为5.51%,对照组釉质脱矿发生率为15.1%,使用氟保护漆后牙釉质脱矿发生率明显降低.结论:牙齿正畸治疗过程中使用氟保护漆对牙釉质脱矿有较好的保护效果.     

开封县氟病区氟斑牙调查分析

氟斑牙是地方性氟中毒最明显的体征之一。本文继开封县村民生活饮用水氟含量调查之后，对氟病区(水氟音量≥1、1mg／l的自然村)进行了氟斑牙横断面调查，现报告如下：     

承德市地方性氟中毒流行现状及高氟区居民氟病知识调查

目的了解承德市地方性饮水型氟中毒流行现状及高氟区居民地方性氟中毒(地氟病)防治知识的认知情况。方法测定承德市监测点居民饮水含氟量;检查当地8～12岁学龄儿童氟斑牙以及测定尿氟含量;问卷调查地方性氟中毒患病情况和机体代谢情况。结果水氟含量均小于1.0 mg/L,监测点8～12岁的学龄儿童氟斑牙检出率在15.79%～18.29%,氟斑牙指数为0.41～0.48之间,总体为边缘流行。儿童即时尿氟均值为1.08 mg/L,两个调查点小学生问卷165份,及格率在29.0%～30.2%之间;家庭妇女问卷97份,及格率34.6%～35.6%之间。结论目前承德市地氟病病情稳定,防治效果显著。但两个监测点的在校学生和家庭妇女问卷及格率均较低,做好健康促进和健康干预工作对于提高病区群众自我防治地方性氟中毒至关重要。因此建议各级卫生行政部门应加大地氟病宣传教育力度。     

氟斑牙固定矫治中托槽脱落的相关因素分析

目的探讨氟斑牙固定矫治中托槽脱落的影响因素。方法中度氟斑牙正畸病人53例,采用固定矫治技术正畸,粘贴托槽996个,观察托槽脱落情况。结果托槽粘贴后第1个月脱落率最高,之后逐渐下降。不同牙位脱落率不同,其中下颌第二双尖牙脱落率最高。同名牙下颌托槽脱落率高于上颌,后牙高于前牙。结论牙位及粘接时间均影响正畸托槽脱落。     

中国局部用氟预防正畸治疗中牙釉质脱矿的系统评价

目的 系统评价我国局部用氟预防正畸治疗中牙釉质脱矿的效果.方法 计算机检索The Cochrane Library(2012年第9期)、MEDLINE (1996～2012.10)、EMbase (1974～2012.10)、CNKI (1994 ～ 2012.10)、VIP(1994 ～ 2012.10)、WanFang Data (1998～2012.10)和CBM (1978～2012.10),纳入关于我国局部用氟预防正畸治疗中牙釉质脱矿的随机和半随机对照试验,同时追溯纳入文献的参考文献.由2位研究者独立对纳入研究的质量进行严格评价和资料提取,而后采用RevMan 5.2软件进行Meta分析.结果 共纳入19篇文献(20个研究),包括26 323颗牙齿.Meta分析结果显示:氟保护漆组的牙釉质脱矿率(8.4％)低于对照组(16.0％)[OR=0.44,95％CI(0.33,0.59),P＜0.00001];局部涂氟组的牙釉质脱矿率(8.3％)低于对照组(17.7％)[OR=0.46,95％CI (0.35,0.60),P<0.000 01];含氟牙膏组的牙釉质脱矿率(9.0％)低于对照组(14.5％)[OR=0.59,95％CI (0.49,0.71),P＜0.000 01];含氟泡沫组的牙釉质脱矿率(11.6％)低于对照组(18.2％) [OR=0.48,95％CI (0.24,0.96),P=0.04];其他方式组的牙釉质脱矿率(12.0％)低于对照组(21.8％) [OR=0.43,95％CI (0.30,0.60),P＜0.000 01].2个结局的GRADE系统推荐分级为低等级,3个为极低等级.结论 国内现有研究显示,局部用氟可以达到预防正畸治疗中牙釉质脱矿的效果,但由于纳入研究的方法学质量较低,本研究结果的可靠性尚需开展更多设计严谨的高质量、大样本的研究予以证实.     

渗透树脂对牙釉质脱矿白垩斑修复作用的研究

目的 探讨牙釉质脱矿白垩斑应用渗透树脂进行修复的作用。方法 选取郑州大学第一附属医院2020年2月至2023年2月接收的70例牙釉质脱矿白垩斑患者,采用随机数字表法分作两组,对照组35例予以微研磨治疗,观察组35例予以渗透树脂修复治疗。比较两组患者的白垩斑面积变化情况、患牙表面显微硬度(SMH)与白垩斑亮度(L^*值)、白垩斑客观与主观评分及总有效率。结果观察组治疗后3个月、6个月时的白垩斑面积/唇面面积(R值)比对照组低(P<0.05);观察组治疗后3个月时的SMH比对照组高,L^*值比对照组低(P<0.05);观察组治疗后3个月时的白垩斑客观与主观评分均比对照组高(P <0.05);观察组治疗总有效率是97.14%,比对照组的80.00%高(P<0.05)。结论 牙釉质脱矿白垩斑应用渗透树脂进行治疗可有效改善白垩斑程度,并改善SMH与L^*值,提升美学效果,进一步提高临床疗效。     

贵州省氟斑牙前牙色度值的测量分析

背景：在口腔烤瓷修复中应用维他经典比色板和维他三维能手比色板比色时不能完全覆盖所有天然牙颜色构成的空间范围,对氟斑牙色度的覆盖范围更少。目的：分析贵州省氟斑牙色度值的分布规律和特征及与正常牙色度值分布的差别。方法：从贵州省氟中毒人群中随机抽取氟斑牙患者317例作为实验组,共计634颗上颌中切牙;随机抽取204名健康人群的正常天然牙作为对照组,共记408颗上颌中切牙,采用国际照明委员会（CIE）推荐的CIE_1976（L^＊a^＊b^＊）表色系统,用ShadeEye-NCC电脑比色仪测定其色度学各要素（L^＊、a^＊、b^＊）值。结果与结论：实验组氟斑牙上颌中切牙色度值范围较对照组大,其中氟斑牙明度均值L＊显著小于对照组（P〈0.05）,a^＊、b^＊均值明显高于对照组（P〈0.05）。实验组氟斑牙上颌中切牙9个区明度L＊值在颈部Ⅱ区最高,切部Ⅸ区最低,从颈部、中部到切部逐渐降低;唇面近中1/3的a^＊、b^＊值均大于远中1/3,且同一受试者左右两侧中切牙的颜色参数差异无显著性意义（P〈0.05）。表明与与天然牙相比,氟斑牙色度值分布较为松散,色度学各要素分布范围广,颜色较正常牙暗且偏红偏黄。     

2009-2012年新疆饮茶型地方性氟中毒病区监测结果分析

目的了解新疆2009-2012年饮茶型地方性氟中毒病区饮用砖茶情况、各监测点8~12岁儿童氟斑牙患病情况、各监测点36~45岁成年人X线氟骨症情况。方法抽取新疆饮茶型地方性氟中毒病区,Dean氏法进行儿童氟斑牙诊断,X线拍片检查成年人氟骨症。结果当地居民饮用砖茶的比例均高于98%。全部砖茶样品氟含量均值范围在544.82~779.79 mg/kg之间,日人均砖茶含氟量均值高于6.08 mg,砖茶含氟合格率均低于28%。监测地区8~12岁学生氟斑牙总检出率为6.08%,氟斑牙指数为0.13,氟斑牙流行强度为阴性。36~45岁成年人氟骨症检出率为11.36%。结论新疆地方性氟中毒病区人群日人均氟摄入量较高,氟斑牙和氟骨症流行情况尚可,砖茶氟含量合格率较低,有关部门应尽快联合推出可以供居民选择的低氟砖茶的品牌。     

遗传性牙釉质发育不全家系分析

目的:分析一遗传性牙釉质发育不全家系的发病情况及病变特征,明确其遗传方式,为进一步基因定位和克隆奠定基础。方法:2003-05在中国山东某市发现一遗传性牙釉质发育不全家系,先证者为1名43岁男性牙釉质发育不全患者。该家系现存活3代,共有36名家庭成员。对先证者及其家族进行口腔检查和全身检查,制备牙齿磨片镜下观察,对该患者及其亲属成员进行家系调查,系谱分析,明确可能的遗传方式。结果:①口腔及全身临床表现:口腔检查可见大量牙石,釉质病变涉及全口牙齿,牙体呈黄褐色,磨耗重,釉质易碎裂剥脱。X射线显示牙釉质密度基本与牙本质相同,髓腔形态未见异常。临床表现符合Witkop1989年分类中的钙化不全型牙釉质发育。全身系统检查排除系统性疾病。无四环素用药史,家族中无近亲结婚者,附近居民无相似病变。②牙齿磨片观察结果:可见釉丛及釉板明显,且数目增多,表明釉质发育较差。③遗传方式:该家系36名成员,3代中均有患者,共检出遗传性牙釉质发育不全患者13人,其中男7例,女6例,传递方式符合常染色体显性遗传的特点。结论:该家系为常染色体显性遗传性钙化不全型牙釉质发育不全家系,为下一步定位该家系致病基因奠定基础。     

Stages in the dissolution of human enamel crystals in dental caries

Various stages in monocrystal dissolution occurring during human enamel were studied by high resolution transmission electron microscopy. After the development of a central core lesion, two mechanisms by which the dissolution spread laterally to the (100) faces of the crystal could be demonstrated on the basis of the systematic orientation of the crystallographic axes. In the first case, the destruction was developing parallel to (120) planes and the borders were limited by (100) planes. In the second type, the development of the lateral side lesion was observed parallel to (100) planes. The carious destruction of the enamel monocrystal occurred as a result of the development of several lateral side dissolutions of the two types described, proceeding along the entire central core lesion.     

Cross-polarized photography in the study of enamel defects in dental paediatrics

An investigative trial was set up to determine the efficacy and practicality of using cross-polarized photography in the assessment of enamel defects. Twenty patients were photographed using this technique. The photography was assessed by ten clinicians, each of whom completed a questionnaire. Two calibrated examiners using the DDE Epidemiology and Screening Indices also undertook assessment. The results show overwhelming evidence to support the use of cross-polarization, with significant increase in agreement between the assessors, than that which could be obtained by conventional photography. It also enhanced the visual detail of enamel defects enabling changes in the appearance to be assessed by the DDE Indices.     

引物长度不对称PCR技术制备单链DNA探针

目的　建立引物长度不对称PCR制备单链DNA探针技术 ,评价单链探针进行斑点杂交的优越性。方法　设计 1对引物 ,其中 1条引物长度为 34bp ,复性温度为 75 2℃ ,另 1条为 2 0bp ,复性温度为 5 5 7℃。首先以 5 2℃的复性温度进行双向对数扩增 ,获得一定数量的双链DNA ,再以 72℃的复性温度进行单向扩增 ,获得单链DNA片段。以含HBVS基因片段的质粒为模板 ,在PCR体系中加入地高辛标记核苷酸直接制备探针 ,并收集 4 0份乙型肝炎患者的血清进行斑点杂交检测。结果　采用引物长度不对称PCR可成功地制备出单链探针且重复性好。对 4 0份乙型肝炎患者血清进行斑点杂交检测 ,HBVDNA检出率为 4 0 %。双链探针和单链探针的检出率一样 ,但单链探针的斑点更清晰 ,背景更好。结论　引物长度不对称PCR可能成为制备单链DNA片段或探针的简便而有效方法。单链探针具有高效和简便特点 ,有广阔的应用前景     

Scanning electron microscopical study on the fluorosis of enamel in rats

Sixteen 28-day-old male rats of Wistar strain, with a mean body weight of 179 g, were divided into two equal groups. Each group of eight animals was maintained for 70 days on drinking water, ad lib., containing no fluorine (control group) and 100 ppm of fluorine (experimental group). All specimens examined were obtained from the incisal portions of the incisors. The following types of enamel specimens were prepared for scanning electron microscopy: (1) acid-etched specimens; (2) acid-etched specimens followed by low temperature microincineration; and (3) fractured specimens. The enamel formed during high fluoride exposure showed marked hypocalcification, that is, the crystallite density in the prism core and interprismatic region was lower than that of control animals. The organic substances appeared to increase in these regions. The changes were prominent in the outer and middle enamel layers. Such changes following fluoride administration appear to indicate an inhibition of enamel maturation, that is, an inhibition of the mineral deposition and/or an inhibition of organic matrix withdrawal.     

In vitro study of the Nd:YAG laser effect on human dental enamel: optical and scanning electron microscope analysis

OBJECTIVE: The Nd:YAG laser irradiation of dental enamel was evaluated in enamel demineralization experiments in a Streptococcus mutans culture media. SUMMARY BACKGROUND DATA: Previous studies had shown that a continuous wave Nd:YAG laser at an energy of approximately 67 mJ may induce an increased acid resistance in human dental enamel when exposed to severe demineralization conditions. METHODS: Enamel windows of 3 x 4 cm in the buccal surface were irradiated with a continuous wave Nd:YAG laser at a wavelength of 1,064 microns using energy densities of from 83.75 to 187.50 J/cm2. Enamel windows of 3 x 4 cm on the lingual surface served as control (without the laser irradiation). The enamel windows were then exposed to a Streptococcus mutans culture media at a temperature of 37 degrees C for 15 and 21 days. The laser effects and demineralization were examined both by optical microscopy and scanning electron microscopy (SEM). RESULTS: A comparison between the lased and the unlased windows of enamel showed fusion and recrystalization of the enamel and increased acid-resistance in all groups irradiated with the Nd:YAG laser. On the other hand, the 3 x 4 delimited enamel surfaces from the control group (not irradiated with the Nd:YAG laser) showed 100% demineralization. CONCLUSIONS: These findings are consistent with the finding that laser irradiation of dental results in significant reduction of the effective solubility of enamel mineral.     

Evidence for the presence of numerous protein components in immature bovine dental enamel

The proteins and peptides of immature enamel were extracted from freshly slaughtered bovine embryos in solutions containing protease inhibitors. No detectable differences were noted in the number of components, their overall amino acid composition, or molecular weights from the proteins and peptides extracted 12-16 h postmortem in solutions which contained no protease inhibitors. These data indicate that the large number of components found in developing bovine enamel is not due to proteolysis occurring during their isolation. Significant amounts of protein components having molecular weights greater than approximately 15,000 were not detected. Therefore, if the ameloblasts initially synthesize only a few high molecular weight protein species, the present data imply that in vivo degradation of the high molecular weight enamel proteins occurs very rapidly after their synthesis and precedes the massive loss of protein which accompanies the final stages of enamel mineralization and maturation.     

Identification of an old frozen alcohol blood sample using a genetic probe technique]

Determination of ethanol concentration in a blood sample drawn from a person who caused a serious car crash showed a level which was markedly above the upper limit tolerated legally i.e. 0.08%. At the court hearing the accused car driver challenged the drunken driving charge and claimed that there might have been a mix up of the blood samples, whereby his was replaced by another blood sample, since the tube containing his blood was not marked with his name. The blood sample had been stored without anticoagulants for about 6 months at -20 degrees C. Due to haemolysis it was impossible to determine conventional haemogenetic marker systems. We therefore tried to extract DNA from the blood sample and to determine the restriction fragment length polymorphism (RFLP) by means of five DNA probes recognizing highly polymorphic single-locus systems as described by Jeffreys et al. We analyzed the RFLP's of both the old blood sample and of fresh blood drawn from the accused car driver and we were able to identify the blood sample as certainly having been taken from the accused.     

新型生物组织成像技术-光学CT对牙釉质早期脱矿检出效能的实验评价

在7颗新鲜拔除的离体人恒牙釉质光滑面制备2 mm×3 mm实验窗,选用pH 4.5的化学酸蚀液在开窗区制备0,12,24,48,72,96,120 h不同时间的早期脱矿人工龋模型,采用自行研发的口腔光学CT系统进行人恒牙早期牙釉质人工龋的体外检出实验研究,设立同一牙齿样本的临床显微摄影和扫描电镜观测对照,以扫描电镜超微组织学检出结果为金标准,评价光学CT体外检出牙釉质早期脱矿的效能.口腔光学CT系统可同时无创获得牙齿表面和截面的脱矿信息,准确检测到脱矿12 h以内微米量级的早期牙釉质表面组织学水平的改变,早于裸眼观察和临床显微摄影.光学CT对于不同酸蚀期实验窗早期脱矿的检出与扫描电镜表征完全一致.口腔光学CT可以牙齿表面快速扫描的方式,非接触、准确、量化地检出牙釉质早期人工脱矿,检出敏感度高,重复性好,可无创获得脱矿部位微米量级量化分析数据.