【作者】 张永忠；

【导师】 张扬；

【作者基本信息】 中国医科大学 ， 口腔临床医学， 2004， 硕士

【摘要】 目的 通过对戴用固定矫治器患者牙菌斑产酸能力的研究，来探讨固定矫治患者戴用固定矫治器期间龋病活跃性的变化。 方法 1、受试者的选择：选择40例受试者，年龄11-16岁，其中男性17例，女性23例，均为恒牙列，无全身疾患，无氟斑牙，均为低龋患者(DMFS＜10，龋齿检查标准参考全国第二次口腔健康流行病调查方案)。所有观察对象经培训后均掌握正确刷牙方法。全部采用方丝弓固定矫治器治疗，分别在戴用固定矫治器之前、戴用固定矫治器1个月、戴用固定矫治器3个月时采集全口牙菌斑。 2、牙菌斑的采集：嘱受试者至少2小时不接触食物，也未采取其他口腔卫生护理措施。样本采集时用10％蔗糖溶液漱口1min，于漱糖后第7min采集全口(下颌前牙除外)牙菌斑。采集时以纱卷隔离唾液，用气枪吹去牙菌斑表面覆盖的唾液。将采集的牙菌斑置于1.5ml离心套管内，碎冰中保存，2小时内送往实验室。 3、牙菌斑液的分离和保存：样本经低温离心(低温离心机：上海市离心机械研究所，TL-5.0台式离心机；离心条件：4℃，15000r/min，15min)，所得上清液即为牙菌斑液。离心后立即吸取1μl牙菌斑液，将其置于装有100μl去离子水的离心管中，充分混匀后保存于-70℃冰箱内。 4、牙菌斑液的检测：应用高效毛细管电泳技术(美国，Unimicro Technologies. Inc. Capd-10322)分析测定有机酸，包括乳酸、甲酸、乙酸、丙酸、丁酸、琥珀酸。石英毛细管(河北永年光纤厂)长57cm，内径75μm。扫描聚焦紫外检测器(VUV-22)，波长214nm。有机酸检测条件：分离电压20kV，反相。分离温度20℃，真空负压进样10s，分离时间7min。电泳缓冲溶液：10mmol/L邻苯二甲酸加0.5mmol/L溴化十四烷基三甲基铵(TTAB)，用0.1mmol/L氢氧化锂(LiOH)调pH至5.7。样本检测方法：取20μl牙菌斑液稀释液加人10~ovL邻苯二甲酸5川，直接检测。结果 本实验6种有机酸在6面n内均得到良好分离，测量值输人S玲510.0软件分析，经t检验结果为固定矫治患者在矫治前、矫治1个月、矫治3个月时糖代谢7面n时牙菌斑液中乳酸、甲酸、乙酸、丙酸、丁酸、唬拍酸等有机酸含量均无显著性差异(p>0.05)。结论 通过本研究可以看出，戴用固定矫治器患者漱糖后的牙菌斑液内乳酸等有机酸含量与矫治前相比无显著性差异。至于个别患者戴用固定矫治器后发生龋病，可能由于粘结在牙面上的矫治器附件可以引起食物残渣滞留，患者未能及时清除，局部牙菌斑滞留时间过长，导致龋齿的发生;同时也可能为托槽周围有过量釉质粘接剂存留，可加重牙菌斑的滞留;或者患者本身牙齿存在釉质发育不全等原因。如此可见，如患者能掌握正确的刷牙方法和刷牙频率，正畸医师在粘接托槽时，避免托槽周围有过量釉质粘接剂存留，则可以避免固定矫治期间龋病的发生。 同时通过本研究也说明人体口腔环境复杂，很难用单一的指标来评价固定矫治器对正畸患者龋病活跃性的影响。更多还原

【Abstract】 OBJECTIVEThe purpose of the present study was to investigate the change of organic acid composition of plaque in multi - bracket fixed treatment, and to study the relationship between fixed orthodontic treatment and the change of caries activity (CA). Effective Capillary Electrophoresis was used to measure the amount of organic acid before and 1 month and 3 month after bonding edgewise appliance. The present study was designed to compare the amount of organic acid in three periods, and a new method, which could evaluate the change of CA correctly in fixed patients, might be founded.METHODS40 patients in general health, 17 male, 23 female, whose age ranged from 11 to 16 years, were selected to participate in this study. All subjects, who hadn’t dental flurosis and were DMFS < 10 in permanent dentition, demonstrated good oral hygiene and were scheduled to undergo orthodontic treatment. Samples of plaque fluid were collected before, 1 month and 3 months after the placement of edgewise appliance in each subject. Before collection, the patients were told to stop eating anything after brushing the teeth for no less than 2 hours. When collecting samples, the subjects were asked to rinse with 10% cane - sugar solution for 1 minute, then the collection sites were isolated with cotton rolls and gently air dried with an syringe to minimize contamination by salivary. The plaque fluid of all teeth except lower incisors was collected after 7 minutes, andput in a centrifuged tube, stored in ice, then taken to laboratory in two hours. The samples were centrifuged at 4t (15000r/min, 15min). The supernatant which was plaque fluid ,was taken 1 l out, and mixed with 100 jxl double distilled water in the centrifuged tube, then stored at -70 until laboratory analysis.Effective Capillary Electrophoresis ( Unimicro Technologies, inc. Capd 10322) was carried out to measure the amount of such organic acids as lactic acid, methyle acid, acetic acid, propyl acid, butyric acid and amber acid. Ou-artzose capillary tube with 57cm long and 75 jjun inner diameter was made in Hebei, Yongnian optic fibre factory. The concentration of organic acids were determined by applying 20 1 diluent of each sample to 5 l 0 - phthalic acid of the buffer by VUV - 22, if the following conditions were fulfilled;(1)vacuum injection; 10seconds(2)separated voltage: 20kv,(3)separated time; 7min.(4)separated temperature: 20 C.(5)the buffer was consisted of 10mmol/l O - phthalic acid and 0. 5mmol/l tetradecyltrimethyl - ammonium bromides(TTAB) ; PH =5.7.RESULTAll kinds of organic acids were separated in 6 minute. Compared with before treatment, the amount of organic acids including lactic acid both 1 month and 3 month after placing edgewise appliance were no significance by t - test ( p >0.05).CONCLUSIONIn this study, compared with pre - treatment, the amount of lactic acid had no significant change in plaque fluid post - treatment . It indicated that the reason that individuals with fixed appliances were more prone to tooth decay was not the change of the ability of producing acids in dental plaque.There was a difference between this study and the previous studies, which suggested that CA increased dramatically in fixed treatment by other method to determine the ability of producing acids in dental plaque. In fact, however, this in vivo study has shown that the oral caries was such a complicated environment that the CA in individuals with fixed appliances was not evaluated by a single factor.更多还原