牙菌斑液对牙釉质矿物的饱和程度与龋活动性的关系

为了解菌斑液对牙齿矿物饱和度随糖漱口的变化，以及与龋活动性的关系，作者选择２２例年龄相同的大学生，按龋齿情况，将其分为３组。第１组无龋（无龋组），第２组ＤＭＦＳ大于１０但无活动性龋（普通龋组），第３组ＤＭＦＳ大于１０且有活动性龋（活动性龋组），测定各受试者在静止时、用蔗糖液漱口后３ｍｉｎ和７ｍｉｎ时的菌斑液中有机酸、ｐＨ值、钙离子活度（有效离子浓度）和无机成分的含量，并计算对于釉质矿物的饱和度。结果表明，糖漱口之后菌斑液乳酸浓度升高、ｐＨ值降低、总钙和离子钙浓度增加。活动性龋组的菌斑液在糖漱口后ｐＨ值和饱和度降低的幅度明显大于无龋组和普通龋组。结论：牙菌斑液对牙齿矿物的饱和度是指示个体接受致龋食物后牙齿脱矿倾向的敏感指标。     

微型pH电极直接测试人牙菌斑pH的应用研究

目的：进一步探讨微型ｐＨ电极在原位检测人牙菌斑ｐＨ的可行性，了解漱糖后对菌斑ｐＨ的影响。方法：采用微型蜂式ｐＨ指示电极直接测试人牙邻面菌斑ｐＨ变化。结果：微型ｐＨ电极与玻璃ｐＨ大电极所测结果基本一致；漱糖后菌斑ｐＨ呈下降趋势，２０ｍｉｎ时达到最低点；无龋组与龋敏感组之间的ｐＨ改变无显著性差异。结论：微型ｐＨ电极适用于在原位直接测试菌斑ｐＨ；漱糖后菌斑ｐＨ发生改变，但龋坏与否的个体之间未见明显不同     

人工牙菌斑致釉质表面钙,磷变化的化学分析

目的：采用多菌系人工龋菌斑模型系统对菌斑－牙釉质界面钙磷运动情况进行化学分析。方法：用微量化学分析法测定钙、磷含量。结果：菌斑一经接触糖后，ｐＨ开始下降，菌斑液中钙磷浓度随之增加，并且同ｐＨ下降程度成正相关。结论：认为早期龋形成中钙磷离子运动直接影响早期釉质龋表层下损害的形成。     

菌斑pH值、游离钙和总蛋白水平与根龋易感性的关系

目的　分析菌斑液成分的动态变化与根龋易感性的关系。方法　比较无根龋组和有根龋组根面牙菌斑液在糖溶液漱口前后 ,所测定pH值、游离钙 (微电极法 )和总蛋白水平 (分光光度法 )的差异。结果　静止状态下 ,无根龋组和有根龋组的pH值 (无根龋组 6 2 4± 0 74,有根龋组 5 96±0 70 )和游离钙 [无根龋组 (0 6 0± 0 46 )mmol/L ,有根龋组 (0 89± 0 5 4)mmol/L]两项指标差异无统计学意义 ;糖漱口后 ,有根龋组的pH(5 14± 0 19)和游离钙 [(1 73± 0 74)mmol/L]水平均低于无根龋组[pH 5 2 8± 0 16 ,游离钙 (2 73± 1 2 5 )mmol/L],差异有统计学意义。总蛋白水平与游离钙含量之间没有相关性。同一个体牙根面与冠面之间菌斑液的三项指标均有显著的相关关系。结论　有根龋组的菌斑液有较强的致龋倾向 ,在细菌酵解糖产酸方面 ,牙根面 (牙骨质 )菌斑与牙冠面 (牙釉质 )菌斑无根本差别     

牙菌斑pH检测技术的应用

牙菌斑ｐＨ检测技术的应用李继遥周学东综述自从Ｓｔｅｐｈａｎ（１９４４）揭示吃糖后菌斑内ｐＨ变化规律后，菌斑ｐＨ变化程度就成为衡量牙菌斑致龋力大小的重要参数。通过测定牙菌斑的ｐＨ变化，可了解菌斑内糖代谢的活动规律，比较各种糖的致龋力，以及了解机体对菌斑...     

乳牙菌斑液短链有机酸含量与龋易感性的研究分析

目的:检测并研究蔗糖溶液漱口前后乳牙菌斑液乳酸、乙酸、丙酸含量与龋病易感性的关系。方法:32名3～5岁完整乳牙列幼儿,无龋组12例(dft=0且CSI=0),有龋组20例(dft(0且CSI(0)。用高效液相色谱仪分离测定10%蔗糖溶液漱口前后菌斑液中乳酸、乙酸、丙酸浓度。结果:10%蔗糖溶液漱口前后,有龋组与无龋组比较,菌斑液乳酸浓度差值有统计学意义(P<0.01)。有龋组漱口前后菌斑液乳酸浓度差值与dft、CSI呈正相关关系(r=0.455,P<0.05;r=0.474,P<0.05)。结论:蔗糖溶液漱口前后乳牙菌斑液乳酸含量的变化与个体龋易感性相关。     

不同部位菌斑pH的动态变化及其与唾液的关系

目的：测定口腔不同部位菌斑在进食后pH的动态变化，探讨不同部位菌斑产酸力的差异及唾液在产酸代谢过程中的作用。方法：采用微型pH电极接触法原位测试患龋状况不同者上、下颌，健康部位与龋坏部位菌斑及唾液pH在含漱糖液前后1h内的变化。结果：不同部位菌斑pH在漱糖后均呈先下降后上升的趋势；患龋状况不同者健康部位菌斑pH在用糖后的变化无统计学差异；上颌菌斑pH变化幅度均较下颌明显；龋洞内菌斑pH变化幅度均较健康部位明显；唾液与菌斑pH间无明显相关性。结论：口腔不同部位菌斑内的产酸代谢活动存在差异，这可能主要与不同部位唾液对糖的清除有关；而唾液的缓冲作用对菌斑的产酸代谢无明显影响。     

牙齿健康部位与龋损部位菌斑pH变化的比较研究

目的研究进食糖后患龋情况不同者健康牙面或龋洞内菌斑pH的变化规律,为进一步探明龋病的发病机制提供依据.方法采用接触法直接在原位测定菌斑pH在漱糖后1 h内的变化.实验分3组,分别为无龋组(CF)、普通龋组(CIA)和龋活跃组(CA),三组均测定健康牙面菌斑pH的变化,龋活跃组另外测定龋洞内菌斑pH的变化,绘制pH随时间变化的曲线,对菌斑基线pH(pHrest)、pH下降的最低值(pHmin)、pH的下降幅度(△pH)及30 min内的曲线下面积(AUC30)进行方差分析.结果各组菌斑pH在漱糖后均下降,约5～10 min后达到最低值,随后缓慢上升,1 h左右可恢复至用糖前的水平;三组健康牙面菌斑pH的变化相似,pHrest、pH min、△pH、AUC30均无显著差异(P＞0.05);龋活跃组龋洞内菌斑pH在漱糖后的变化趋势与三组健康牙面相似,但龋洞内菌斑的pHrest明显较健康牙面低(P＜0.01),用糖后pH的下降更为明显,pHmin和AUC30均较健康牙面小(P＜0.01或P＜0.05),且恢复到用糖前基线水平所需时间亦较长.结论龋洞内的菌斑产酸力较健康牙面高,进一步验证了龋病的发生是局部菌斑产酸力增强所致.     

托槽周围牙面菌斑体内蔗糖反应的研究

目的本文对托槽周围牙面菌斑体内蔗糖反应的变化进行了研究,探讨了正畸矫治中牙面菌斑致龋能力的变化。方法随机选择18例患者作为受试者。采用随机数字法,在其牙弓一侧使用0.20mm不锈钢丝结扎,另一侧使用弹力结扎圈结扎。应用钯微电极测定不同的托槽粘接时间漱糖前后各时间点菌斑的原位pH值。结果托槽粘结后牙面菌斑漱糖前pH值有下降的趋势,在丝侧粘结三周组有显著性差异(P<0.05)。托槽粘接三周组pH值在漱糖后各时间点均有降低的趋势,但粘接前后牙面菌斑体内蔗糖反应无显著差异。丝侧与圈侧牙面菌斑之间也不存在显著差异。结论托槽粘接后有机酸有在菌斑中滞留的趋势,提示牙面菌斑致龋能力有增强的趋势,正畸中的口腔卫生维护应加强。     

菌斑原位pH在判断个体龋易感性中的作用

口内牙齿表面菌斑的原位pH既能反映细菌代谢产酸的能力,也反映局部环境缓冲和转运酸的能力。本研究使用钯-微触电极测量龋活跃者(CA)和无龋者(CF)在用10％蔗糖溶液漱口前后菌斑的原位pH,以评价原位pH测定在判断个体龋易感性中的作用。结果表明,龋活跃组菌斑pH在漱糖前后各时间点均较无龋组低;龋活跃组与无龋组在漱糖后菌斑下降的最低pH相近,但龋活跃组菌斑pH回升速度慢,导致低pH水平持续时间长。上颌牙菌斑pH水平较下颌牙菌斑pH水平低,而左右侧牙菌斑pH水平大致相同,提示唾液在维持菌斑pH水平中的主导作用。     

Association of caries activity with the composition of dental plaque fluid

This study tests the hypothesis that caries activity is associated with lower degrees of saturation with respect to enamel mineral in dental plaque fluid following sucrose exposure. Plaque fluids were obtained from caries-free, caries-positive, and caries-active subjects. Samples were collected before and at 3 and 7 min after a sucrose rinse on consecutive weeks and analyzed for organic acids, inorganic ions, pH, calcium activity, and, in selected samples, total protein. After sucrose, pH values were significantly lower in the caries-active group in comparison with the caries-free and caries-positive groups. Total and free calcium concentrations increased with decreasing pH, with free calcium being about one-third of total calcium. The caries-active group exhibited significantly lower degrees of saturation with respect to enamel mineral, after sucrose, and had significantly higher mutans streptococci levels in plaque than did the caries-free samples. Thus, saturation levels in post-sucrose plaque fluids reflect the cariogenic potential of dental plaque.     

Changes in lactate and other ions in plaque and saliva after a fluoride rinse and subsequent sucrose administration

The purpose of this study was to examine plaque and saliva composition after a fluoride rinse and subsequent sucrose application. Fifteen subjects accumulated plaque for 48 h, and then rinsed with a fluoride rinse based on 228 microg/g (ppm) Na2SiF6 and some received no rinse. After 60 min, upper and lower buccal molar plaque samples and 1-min saliva samples were collected. The subjects then rinsed with 10% g/g sucrose solution, and 7 and 15 min later, a second and a third set of samples were collected. Plaque fluid and clarified saliva were then recovered from these samples by centrifugation, and the remaining plaque acid extracted. The plaque fluid, centrifuged saliva, and plaque extract samples were then analyzed using micro techniques for pH, free calcium, phosphate, organic acids (plaque fluid and saliva only) and fluoride. Considering both the fluoride rinse and no-rinse groups, the most notable compositional changes in saliva 7 min after the sucrose rinse were pH -0.40 unit, free calcium 0.42 mM, lactate 5.2 mM, phosphate -1.3 mM, and fluoride 2.8 microM; while in plaque fluid, the corresponding changes were pH -1.59 unit, free calcium 1.5 mM, lactate 35 mM, phosphate -1.6 mM and fluoride -26 microM. After sucrose rinsing, undersaturation was found with respect to dicalcium phosphate dihydrate in saliva and plaque fluid and with respect to tooth enamel in some plaque fluid samples. Plaque fluid composition appeared to be strongly influenced by salivary clearance, diffusive loss of ions into the water phase of the rinse, and lower jaw pooling of the sucrose and fluoride components of the rinses. After the experimental rinse, the fluoride concentration in plaque fluid [86 +/- 22 mM (upper molar site), 162 +/- 150 mM (lower molar site)], saliva (26 +/- 18 mM), and whole plaque [99 +/- 97 microg/g (upper molar site), 197 +/- 412 microg/g (lower molar site)] was comparable to the values in previous studies using this rinse. These very high plaque fluid fluoride concentrations, compared with the 'no-rinse' samples, induced an approximately 0.3-unit increase in the plaque fluid pH 7 min after the sucrose rinse, a small decrease (approximately 20%) in lactate production and a modest increase in enamel saturation. Although these changes were all statistically significant, no correlation was found between the decrease in lactate concentration and plaque fluid fluoride, pH or whole plaque fluoride.     

2种胶姆糖对菌斑pH值的影响

目的：观察咀嚼2种胶姆糖后口腔菌斑pH值的变化情况.方法：选择8例健康受试者（年龄23～27岁,男4例,女4例）参加3次试验,每次实验开始前停止刷牙24h,在使用10%的蔗糖溶液漱口前以及漱口后5、10、15、20min,用Beetrode pH微电极测量口腔菌斑的pH值,作为基线值.1周后先测量静息pH值,再用蔗糖溶液漱口,1min后给予无糖胶姆糖咀嚼,在5、10、15、20min时间点,分别测量非咀嚼侧的菌斑pH值.1周后重复上述实验,胶姆糖改为含茶多酚胶姆糖.应用SPSS10.0统计软件包对数据进行单因素方差分析和SNK分析.结果：与基线值比较,咀嚼2种胶姆糖都能有效防止由于含漱蔗糖水导致的菌斑pH值下降,并使pH值维持在静息pH值以上.2种胶姆糖之间无显著性差异（P＞0.05）.结论：咀嚼2种胶姆糖均能防止菌斑pH值下降,减少患龋危险.     

Plaque fluid pH, calcium and phosphorus responses to calcium food additives in a chewable candy

Fourteen subjects between 7 and 17 years of age with an equal distribution of low and high caries activity were given: (1) a 10% sucrose rinse, (2) a reference candy, (3) a reference candy with 3% dicalcium phosphate dihydrate, and (4) a reference candy with 0.75% calcium lactate on four different occasions. Plaque samples were collected before and at 15-min intervals after the sucrose rinse or food challenge for a period of 1 h on each occasion. Plaque samples were centrifuged and the extracellular plaque fluid analysed by a microtechnique for pH, total calcium and inorganic phosphorus concentration. There was no significant increase in calcium and phosphorus in plaque fluid for the group using candy with added calcium compared to the reference candy or sucrose rinse. There was no significant difference between the measurements in subjects grouped as caries active or inactive. The results suggest no benefit can be expected from adding dicalcium phosphate dihydrate and calcium lactate to candy to decrease demineralization during a cariogenic challenge.     

Effect of a water rinse on 'labile' fluoride and other ions in plaque and saliva before and after conventional and experimental fluoride rinses

Labile reservoirs are important in maintaining ion concentrations in oral fluids, especially after a fluoride dentifrice application, where a persistent increase in fluid fluoride can mitigate or reverse caries progression. In this study, the effect of experimental and conventional fluoride rinses on the in vitro and in vivo water-induced release of fluoride, calcium, phosphate, acetate and hydrogen ions from oral reservoirs was examined. At the start of each experiment, 13 subjects rinsed either with a conventional 228-ppm fluoride NaF rinse, a 228-ppm fluoride controlled-release rinse (CR rinse) or received no rinse. Sixty minutes later upper and lower molar plaque samples and 1-min saliva samples were collected. The subjects then rinsed with deionized water for 1 min, and 7 min later, a second set of samples was collected (in vivo study). Plaque fluid and clarified saliva were then recovered from samples by centrifugation, and the remaining plaque mass was sequentially extracted with water and acid to measure the water-extracted and total whole-plaque fluoride (in vitro study). All the samples were analyzed using microtechniques for pH, free calcium, phosphate, organic acids (plaque fluid) and fluoride (plaque fluid, centrifuged saliva and plaque extracts). Results showed that in vivo water rinsing decreased acetate and phosphate in plaque fluid, and fluoride in plaque fluid and saliva, but had no effect on plaque fluid pH. In vivo water rinsing, however, increased plaque fluid free calcium, apparently due to water-induced loss of calcium-binding ions. Water- or fluoride-rinse-induced changes in plaque fluid concentration were greater at the lower molar site, suggesting that rinse pooling may influence ion distribution. Before the water rinse, plaque fluid, saliva and whole-plaque total fluoride values were 1.7, 2 and 4 times higher after the CR rinse compared to the NaF rinse. Furthermore, the CR rinse deposited approximately 11 times more water-extracted fluoride compared to the NaF rinse, suggesting a 'more efficient' precipitation of 'labile' or 'loosely bound fluoride'. The results presented here, and in previous studies, suggest the possibility of formulating effective fluoride dentifrices with a lower fluoride content than is currently in use.     

Effect of in situ plaque mineral supplementation on the state of saturation of plaque fluid during sugar-induced acidogenesis

Dental plaque fluid is normally supersaturated with respect to enamel mineral but this may change to a state of undersaturation when plaque pH falls following sugar exposure, placing the adjacent enamel at risk of caries. We have determined the saturation status of the fluid in both resting and fermenting plaque following mineral supplementation. Eleven subjects abstained from oral hygiene and rinsed their mouth 3 times/d for 3 d with a placebo solution or with test solutions designed to enrich plaque with hydroxyapatite or fluorhydroxyapatite. On the morning of day 4, plaque samples were collected before and after exposure to 10% sucrose. Compared to the placebo, use of the test rinses resulted in significantly higher concentrations of Ca, P and F in plaque residue. In plaque fluid, higher post-sucrose Ca2+ free concentrations and saturation levels with respect to enamel mineral and fluorapatite were found after use of the hydroxyapatite rinse compared to the placebo, effects that probably resulted from the release of cell-bound Ca2+ as well as from the dissolution of apatite. Thus, some evidence was obtained that the test mouthrinses can counteract the fall in saturation level found when plaque is exposed briefly to sucrose. Potential long-term benefits of the test mouthrinses deserve further study.     

A study of influence of sugars on the modulations of dental plaque pH in children with rampant caries, moderate caries and no caries

The present study is undertaken to find out the pH of resting plaque in children with no caries, moderate caries and rampant caries and to determine the modulations of plaque pH with different sugar solution rinses viz: sucrose, glucose and fructose. The study was carried out on forty five children, in the age group of 3-10 years (25 males and 20 females). The child was given 10 ml of test solution and was asked to rinse and swish it in the mouth for a period of 30 sec. Plaque samples were taken from 20 different spots after 5, 10, 20 and 30 min of the rinse and pH values of all the samples were determined. Results show that there was a statistically significant (P<0.05) difference between the pH values of plaque at different intervals of time with sucrose, fructose and glucose solution rinse in children with moderate caries, rampant caries as compared to the caries free group. Sucrose was found to be highly cariogenic in all the children with a greater potentiating effect in moderate and rampant caries. Glucose also appeared to have a cariogenic role while fructose had the least of it all.     

Composition of pooled plaque fluid from caries-free and caries-positive individuals following sucrose exposure.

The composition of pooled plaque fluid from five population samples was determined before and at selected times (7, 15, 30, and 60 min) after a 10% sucrose rinse. Subjects were grouped according to caries status (caries-free, CF, DMFS = 0; caries-positive, CP, DMFS > 10). Samples were also studied from white-spot surfaces and from sound surfaces of the same mouths of two additional CP groups. Plaque fluid was isolated by centrifugation and analyzed for organic acids, inorganic ions (ion chromatography), and pH (microelectrodes). Prior to sucrose exposure, plaque fluids from the CF subgroups and from sound surfaces of the CP subjects had higher pH values than samples from CP subgroups and from white-spot surfaces, respectively; the ionic compositions were otherwise similar. Starved plaque fluids were also found to be supersaturated with respect to enamel and to a significantly greater degree in the CF samples, suggesting that CF plaque fluid may have a greater remineralization potential than CP samples. Following sucrose exposure, a rapid decrease in plaque fluid pH was observed, which corresponded primarily to lactic acid production. For all times examined, mean pH and DS(En) values were lower and lactic acid concentrations were higher in the CP samples than in the CF samples; noted differences were statistically significant at 7 min for pH and DS(En), and at 7, 15, and 30 min for lactic acid. Lower values of DS(En) suggest that plaque fluid from CP subjects had a measurably greater cariogenic potential.(ABSTRACT TRUNCATED AT 250 WORDS)