喷磨预处理对离体氟斑牙正畸托槽粘接强度的影响

目的筛选一种使氟斑牙与托槽有较高粘接强度的临床可行的粘接方法。方法选择15例氟斑牙正畸患者拔除的60颗第一前磨牙为研究对象,采用随机区组设计方法分为15个区组,每区组包括每位患者的4颗牙齿,区组内采用随机排列表法分为A、B、C、D 4小组,每小组即包括每位患者的1颗牙齿,共计15颗。4小组采用不同方法粘接托槽,分别为常规酸蚀后用釉质粘接剂粘接、喷磨预处理后用釉质粘接剂粘接、自酸蚀后用Bond粘接剂和光固化复合树脂粘接、喷磨预处理和自酸蚀后用树脂粘接剂和光固化复合树脂粘接;然后测定4小组的粘接强度和托槽底面粘接剂的余留情况。结果A、B、C、D 4小组的托槽/牙面剪切强度测试结果分别为（2.247±0.261）MPa、（5.374±0.469）MPa、（4.345±0.401）MPa、（5.791±0.636）MPa,4组间存在统计学差异（P<0.01）,D组剪切强度最大,其次为B、C组,A组最小。4组样本在去除托槽时残留粘接剂的情况无统计学差异（P>0.05）。结论氟斑牙面先用空气喷磨机喷磨,然后进行自酸蚀和树脂粘接托槽是一种较为可行的方法。     

牙齿漂白剂对正畸托槽粘接强度的影响

目的:评价三种牙齿漂白剂对自酸蚀粘接系统粘接正畸托槽粘接强度的影响。方法:将100颗人前磨牙均分为四组:空白对照组(组1)、38%过氧化氢漂白组(组2)、10%过氧化脲漂白组(组3)和20%过氧化脲漂白组(组4),漂白牙齿后即刻使用自酸蚀正畸粘接系统Transbond Plus SEP将托槽粘接在牙面上,测量各组的抗剪切粘接强度,评价其剩余粘接剂指数,对结果进行统计学分析。结果:空白对照组的抗剪切粘接强度高于各漂白组,组2的抗剪切粘接强度高于组3和组4,而组4的抗剪切粘接强度最低,其差异均具有统计学意义(P<0.05)。各组的剩余粘接剂指数差异均有统计学意义(P<0.05),剩余粘接剂指数最低者为空白对照组,最高者为20%过氧化脲组。结论:在使用自酸蚀粘接系统粘接正畸托槽前应禁止使用过氧化物漂白牙齿,特别是高浓度的过氧化脲。     

不同正畸粘接系统在托槽再粘接中的应用评价

目的：检测使用不同正畸粘接系统再粘接托槽对其剪切粘接强度的影响,以探讨提高临床再粘接效率的方法。方法：选择60颗正畸减数的恒双尖牙,依据不同粘接系统随机分为3组：津京釉质粘接剂（A组）、TransbondXT光固化粘接系统（B组）及Transbond自酸蚀粘接系统（C组）。所有样本均先用津京釉质粘接剂粘接托槽,24h后去除托槽重新粘接新托槽,测量3组托槽再粘接的剪切强度及粘接剂残留指数（AdhesiveRemnantIndex,ARI）。结果：3组托槽再粘接剪切强度分别为（8．615±2．460）MPa、（8．807±1．801）MPa及（8．144±3．023）MPa,组间剪切强度差异无显著性;ARI评分表明：C组牙面上残留的粘接剂明显少于其他两组。结论：采用自酸蚀粘接系统再粘接托槽的剪切强度与其它两种粘接系统相当,并且去除托槽后牙面残留粘接剂较少。     

陶瓷托槽Crystaline Ⅳ剪切及拉伸粘接强度的研究

目的研究临床常用的多晶体氧化铝陶瓷托槽CrystalineⅣ（Tomy,Japan）剪切及拉伸粘接强度。方法 15颗离体上颌双尖牙用于剪切粘接实验,15颗离体下颌双尖牙用于拉伸粘接实验。使用37%液体磷酸和京津釉质粘接剂粘接CrystalineⅣ,在0.9%生理盐水中室温保存24小时。电子万能试验机检测剪切及拉伸粘接强度。托槽脱落后记录粘接剂残留指数（ARI,adhesive remnant index）,陶瓷托槽的折断数目和釉质表面出现肉眼可见缺损的牙齿数目。结果 Crystaline IV的剪切和拉伸粘接强度分别为14.47±2.43MPa和6.53±2.26MPa,剪切粘接强度显著高于拉伸粘接强度。两种加载方式的主要去除部位均在粘接剂内,所有样本未出现陶瓷托槽折断和肉眼可见的釉质缺损。结论使用京津釉质粘接剂粘接CrystalineⅣ能够获得满足临床治疗需要的剪切及拉伸粘接强度,剪切粘接强度显著高于拉伸粘接强度。加载拉伸力可能是相对安全的去除陶瓷托槽的方法。     

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本研究通过对比釉质磨除的氟斑牙与正常牙之间托槽抗剪切粘接破坏力的差异,探讨釉质局部磨除在提高氟斑牙患者托槽粘接的效果,为临床氟斑牙托槽粘接提供有效的方法。     

加强塑料托槽和粘接剂界面粘接强度方法的研究

目的:探讨加强塑料托槽粘接强度的方法,提高塑料托槽的粘接强度。方法:60个离体人前磨牙随机平均分为三组,对照组塑料托槽不做任何处理;自凝牙托水组托槽经自凝牙托水处理,硅烷偶联剂组托槽经硅烷偶联剂处理。三组牙齿和托槽均用京津釉质粘接剂粘接,在37℃蒸馏水中储存24h后测量其抗剪切强度,并评估去粘接后牙面残留的粘接剂止数(ARI)。结果:对照组与两实验抗剪切强度组间比较有显著性差异(P<0.05),而两实验组比较无显著性差异(P<0.05);三组ARI记分无显著性差异(P>0.05)。结论:用自凝牙托水和硅烷偶联剂处理托槽底板可增加塑料托槽的抗剪切粘接强度,使其能满足正畸临床矫治力的要求。     

三种非金属托槽抗剪切强度比较

目的 比较京津釉质粘接剂粘接三种非金属托糟的抗剪切强度，评估托槽去除后牙面残留粘接剂指数（adhesive remnant indexes，ARI），为临床合理选择非金属托槽提供指导。方法 60颗人类前磨牙随机均分为三组，用京津釉质粘接剂分别粘接陶瓷托槽、有机玻璃托槽和聚碳酸酯托槽，测定并记录其抗剪切强度和托槽去除后牙面残留粘接剂指数。结果 三种托槽的抗剪切强度和ARI记分情况均不全相同（P〈0.05），组间比较发现陶瓷托槽组与另两组间差别显著（P〈0．01），而有机玻璃组与聚碳酸酯组间无显著差别（P〉0．05）。结论 在应用京津釉质粘接剂粘接托槽时，陶瓷托槽的粘接强度足可以满足正畸临床矫治要求，而有机玻璃托槽和聚碳酸酯托槽的粘接强度较低以至不能满足正畸临床矫治要求，应谨慎使用。     

两种正畸粘接系统对金属和陶瓷托槽粘接强度的影响

目的:评价传统正畸粘接系统和自酸蚀粘接系统分别对金属托槽和陶瓷托槽的粘接强度。方法:将100颗人前磨牙均分为4组:金属托槽/传统粘接系统组(1组)、金属托槽/自酸蚀粘接系统组(2组)、陶瓷托槽/传统粘接系统组(3组)、陶瓷托槽/自酸蚀粘接系统组(4组),使用Transbond XT树脂糊剂将托槽粘接在牙面上,测量各组的抗剪切粘接强度,并评价其剩余粘接剂指数,对结果进行单因素方差分析。结果:统计学分析表明金属托槽的抗剪切粘接强度高于陶瓷托槽,其差异具有统计学意义(P<0.05);1组和2组平均抗剪切粘接强度的差异无统计学意义(P>0.05),3组和4组间的差异也无统计学意义(P>0.05);各组剩余粘接剂指数的差异无统计学意义(P>0.05),但各组的粘接强度与剩余粘接剂指数有平行相关性(P<0.05)。结论:金属托槽的粘接强度高于陶瓷托槽;自酸蚀粘接系统与传统粘接系统都可满足正畸临床粘接托槽的需求;大部分样本的粘接失败发生在托槽/粘接剂界面或粘接剂内部破坏,表明牙釉质受损的几率较低,且粘接强度和剩余粘接剂指数之间存在统计学相关性。     

用于正畸托槽粘接的玻璃离子粘固剂的抗剪切强度

目的　研究用于正畸托槽粘接的树脂改良型玻璃离子粘固剂的抗剪切强度。方法　 30颗离体前磨牙平均分为 2组。一组用树脂改良型玻璃离子粘固剂 (Advance)粘接方丝弓正畸托槽 ,另一组用复合树脂釉质粘接剂 (DM)粘接。 2 4h后用材料力学试验机检测两种材料的抗剪切强度 ,统计牙面上粘接材料的残留指数。结果　 2种粘接材料的抗剪切强度相似 [玻璃离子粘固剂为 (6 86 2±2 142 )MPa,复合树脂粘接剂为 (7 183± 3 2 0 5 )Mpa],差异无显著性。结论　体外研究中 ,树脂改良型玻璃离子粘固剂的抗剪切强度已达到复合树脂釉质粘接剂的水平 ,具有临床应用前景     

托槽即刻粘接强度与24小时粘接强度的对比研究

目的　对托槽粘接后的即刻粘接强度和 2 4小时后的粘接强度进行对比研究。方法　选正畸需要而拔除的双尖牙为实验样本 ,将实验分为四组 ,每组 10颗牙齿。对每一牙面粘接方丝弓托槽。以材料力学实验机分别对四组进行即刻抗剪切强度、即刻抗张强度、2 4小时后抗剪切强度以及 2 4小时后抗张强度的测定 ,并对每一牙面上的粘接剂残留量进行统计。结果　无论是抗剪切强度还是抗张强度 ,即刻粘接组与 2 4小时后粘接组间均存在显著性差异。结论　牙面托槽粘接后的即刻粘接强度远远要小于2 4小时后的粘接强度     

Variation in periodontal referral in 2 regions in theUK

This study investigated the periodontal referral patterns of general dental practitioners (GDPs) in Northern Ireland (NI) and North West England (NWE). A questionnaire dealing with periodontal referral was sent to all 520 GDPs registered in NI and to 274 GDPs in NWE. A usable return was made by 355 (68%) in NI and 189 (70%) in NWE. The NI dentists made significantly more periodontal referrals (median 5, range 0-80) in the year preceding the survey than those in NWE (median 2, range 0-50), p<0.001. Distance was the only factor significantly related to the referral rate in both regions with those who practised more than 25 miles from a specialist referring significantly fewer patients in both regions. In NI, there was a trend towards increased periodontal referral by GDPs who had attended more postgraduate courses; however, in NWE, this was not the case. The GDPs in NWE were significantly less likely than those in NI to refer patients with medical conditions. It is concluded that there is considerable variation in periodontal referral both within and between the 2 regions studied. It is further concluded that in many cases, non-disease factors, such as the accessibility of the specialist service, have powerful effects on the decisions made by dentists and patients in these regions (NI and NWE) in relation to periodontal referral. Much of the variance in referral in North West England, as in Northern Ireland, remains unexplained.     

云南省五岁儿童乳牙龋病调查分析

目的：了解云南省５岁儿童乳牙龋齿患病情况。方法：随机抽取云南省三个城市三个农村的２１３２名５岁常住儿童,采用第二次全国口腔健康流行病学调查标准调查龋齿患病情况。结果：云南省５岁儿童乳牙患龋率为７５．７５％,龋均为４．４４,充填率仅为６．５７％,仅占构成比的４．３９％。结论：云南省５岁儿童乳牙龋齿患病率高,充填率低。儿童龋病防治应注重两个方面：１．加强对家长和教师的幼儿口腔卫生保健知识及方法的宣传。     

Changes in cyclooxygenase metabolities in experimental periodontitis in Macaca mulatta

The four principal metabolites of cyclooxygenase (CO) were examined during the progression of experimental periodontitis in the rhesus monkey Macaca mulatta. Thirty-two monkeys were divided in four disease-matched groups. Three groups were treated with flurbiprofen, a potent CO inhibitor, at either 0.027, 0.27 or 7.1 mg/kg/day delivered systemically by a subcutaneously-implanted osmotic mini-pump. We have previously described the findings indicating that flurbiprofen treatment significantly retarded clinical attachment loss (ALOSS), redness and radiographic bone loss (BLOSS). This investigation focuses on the changes in CO metabolites which occur during disease progression of ligature-induced periodontitis and on the dose-response relationship of flurbiprofen, as it relates to disease inhibition and the suppression of ARA metabolites within the crevicular fluid (CF). In untreated animals there was a statistically significant 3-fold increase in CF levels of prostaglandin E2 (PGE2) and thromboxane B2 (TxB2) at 3 months, as compared to baseline, which positively correlated with increases in redness, bleeding, ALOSS and BLOSS. CF-PGE2 and TxB2 levels reached a 6-fold peak at 6 months and returned to baseline by 12 months. Flurbiprofen (Fb) prevented the 3-month rise in TxB2, but did not affect the increase in PGE2. At 6 months, Fb administration caused a dose-dependent inhibition of both PGE2 and TxB2. Probit analysis of the dose-response data revealed that the concentration of Fb which caused a 50% inhibition of CF-TxB2 level (the IC50 value for TxB2 synthesis) was approximately two logs lower than the IC50 value for PGE2 synthesis, i.e. TxA2-IC50 = 0.013 vs. PGE2-IC50 = 1.35 mg flurbiprofen/kg/d. The slopes of the PGE2 and TxB2 inhibition curves were identical, consistent with a similar mechanism or singular enzyme for the site of action of Fb inhibition of CO activity. However, the kinetics and sensitivity of Fb inhibition were significantly different for the CO activity responsible for TxB2 and PGE2 synthesis, perhaps due to different compartmentalization of CO within different cell types.     

Mast cells in masseter muscle in experimental bruxism in man

Three human subjects performed tooth grinding for 25 min, and after 20 h biopsies of the right and left masseter muscles were examined for their contents of mast cells. In comparison with specimens from a control group of three subjects, there was an increase of degranulating mast cells in muscles that had performed bruxism.