两种材料修复体的冠边缘粘性放线菌的检测

目的 研究老年患者中,两种材料修复体冠修复前后不同时期冠边缘龈下菌斑中粘性放线菌的定植变化。 方法 收集门诊就诊老年患者中下颌第一磨牙要求行冠修复的患者共60例,随机编入二氧化锆组与钯银合金烤瓷冠组,采用自身前后对照法,将牙体预备前的患牙设为对照组,冠修复后6个月、12个月的患牙设为试验组,并分别在这3个时期收集冠边缘龈下菌斑,采用荧光定量聚合酶链式反应技术对临床样本进行粘性放线菌的相对定量分析。 结果 与修复前比较,二氧化锆全瓷冠组修复后6个月、12个月的粘性放线菌相对定量值差异无统计学意义（P＞0.05）;钯银合金烤瓷冠组修复后6个月、12个月的粘性放线菌相对定量值差异有统计学意义（P＜0.05）。 结论 二氧化锆全瓷冠可能可以更好地降低冠修复后患继发龋的风险。     

插销式二氧化锆嵌体冠应用于短冠磨牙修复的研究

目的评价低牙合龈距短冠磨牙修复中使用插销式二氧化锆嵌体冠的可行性。方法收集16颗短冠磨牙,经过完善的根管治疗及牙周治疗2周后行牙体及根管预备。将插销桩和二氧化锆嵌体冠结合成一体的插销式二氧化锆嵌体冠,用插销式二氧化锆嵌体冠对16颗低牙合龈距（小于4 mm）短冠磨牙修复治疗。修复后进行6～12个月的临床追踪观察。结果除1颗患牙因根尖周炎拔除外,其余15颗患牙的插销式二氧化锆嵌体冠均边缘密合,外形美观,固位良好,无松动脱落,基牙牙龈健康,咀嚼功能正常。结论插销式二氧化锆嵌体冠可用于短冠磨牙的修复。     

老年根面龋的细菌学研究

目的 :通过对根面龋菌斑微生物的定量分析 ,进一步了解根面龋的致龋机制。方法 :选择 15例老年根龋患者 ,分别对其根面龋、冠龋、无龋根面的菌斑微生物中的变形链球菌、乳酸杆菌、放线菌进行菌落计数。结果 :变形链球菌在根龋和冠龋中的检出率高达 10 0 % ,占总链球菌 6 4 78± 2 2 36 %和 77 17± 14 2 6 % ,明显高于无龋根面 ;放线菌在根龋中的检出率明显高于冠龋。结论 :变形链球菌 ,放线菌是根面龋的优势菌。     

口腔放线菌对白假丝酵母菌拮抗作用的体外实验研究

目的观测3种口腔放线菌对白假丝酵母菌的生长有无抑制作用。方法采用直接点种法观察抑菌圈,分别采用反点种菌落计数法和液体共培养法,观察在口腔放线菌作用下白假丝酵母菌菌落数量的变化。结果1）各实验组均未观察到清晰的抑菌圈;2）在黏性放线菌软琼脂上的白假丝酵母菌菌落数较对照组明显减少（P<0.05）;在溶牙放线菌和内氏放线菌软琼脂上无明显白假丝酵母菌生长,与对照组相比差异有统计学意义（P<0.01）;黏性放线菌组与溶牙放线菌组、内氏放线菌组相比,白假丝酵母菌生长差异有统计学意义（P<0.01）;3）分别与3种放线菌共培养的白假丝酵母菌菌落数量减少,与对照组相比差异有统计学意义（P<0.05）;3个实验组间差异无统计学意义（P＞0.05）。结论口腔黏性放线菌、溶牙放线菌和内氏放线菌对白假丝酵母菌的体外生长有抑制作用。     

伊犁黑蜂蜂胶对口腔主要致龋细菌生物膜作用的实验研究

目的 研究伊犁黑蜂蜂胶对口腔常见致龋细菌生物膜的影响,探讨其防龋效果及可能的防龋机制。方法 通过结晶紫染色法测定黑蜂蜂胶对口腔常见致龋菌（变异链球菌、表兄链球菌、血链球菌、黏性放线菌、内氏放线菌）的最小生物膜清除浓度（MBEC）;培养测试细菌24 h单菌生物膜,加入MBEC及以下的3个浓度配置成初始pH值为7.0的含药培养基,厌氧培养24 h后测pH值,并计算pH变化值以检测不同浓度黑蜂蜂胶对测试菌单菌生物膜产酸能力的影响。蒽酮法测定MBEC及以下的3个浓度的黑蜂蜂胶对变异链球菌24 h单菌生物膜产生水不溶性胞外多糖的影响。结果 黑蜂蜂胶对变异链球菌、表兄链球菌、血链球菌、黏性放线菌、内氏放线菌的MBEC分别是6.25、1.56、3.13、0.78、0.78 mg•mL-1;黑蜂蜂胶可使各测试菌单菌生物膜ΔpH降低,蜂胶各组与对照组相比差异均有统计学意义（P<0.05）;在MBEC浓度时,蜂胶可使变异链球菌合成水不溶性胞外多糖的能力降低。结论 伊犁黑蜂蜂胶具有一定的防龋效果,其可能的防龋机制是通过有效清除口腔主要致龋细菌单菌生物膜,抑制测试菌株产酸、合成水不溶性胞外多糖的能力起作用的。     

远中楔形瓣切除术应用于短龈距第二磨牙冠修复的临床效果观察

目的探讨第二磨牙远中龈距不足的病例应用远中楔形瓣术后冠修复临床效果。方法收集30例第二磨牙远中龈距不足的病例,均排除手术禁忌证,采用远中楔形瓣切除过多牙龈组织,必要时去除少量牙槽骨。术后常规医嘱,术后临时冠修复,1周拆线。术后4-6周永久修复体修复。完成永久修复时、修复后6个月、修复后12个月进行随访,并记录3个时期患牙远中的牙冠高度,以及患牙和对照牙的远中龈沟出血指数（SBI）,采用SPSS 16.0进行分析。结果术后所有病例远中龈距均满足了牙体预备所需要的空间,永久修复体功能形态恢复良好。30例修复体固位效果良好,龈缘位置无明显变化,不同时期远中临床牙冠高度变化不显著（F=1.279,P=0.284）;牙龈无明显红肿,远中SBI与对侧同名牙之间差异均无统计学意义（3个时期的比较分别为t0=2.283,P0=0.534;t6=-0.767,P6=0.722;t12=2.129,P12=0.263）。结论游离端磨牙远中楔形瓣是改善远中临床牙冠短的磨牙冠修复效果的一种有效方法。     

含钛医学合金烤瓷冠修复对龈沟细菌的影响

目的 了解含钛医学合金烤瓷冠对龈沟细菌的影响.方法 选择8例两侧均需冠修复的临床病例,一侧含钛医学合金烤瓷全冠修复,另一侧贵金属合金烤瓷全冠修复.采用经典细菌培养鉴定方法及菌落形成单位计数(colony formine unit/mL,CFU/mL)的检测方法,分别比较两种修复体在戴牙后2周、3个月时龈沟菌落与戴牙1周时(基线)的差别.结果 与贵金属合金烤瓷全冠比较,含钛医学合金烤瓷全冠戴牙后总菌落及消化链球菌、产黑普氏菌、二氧化碳嗜纤维菌等部分牙周可疑病原菌的菌落形成单位计数差异有统计学意义.结论 含钛医学合金烤瓷冠的戴入可能改变龈沟菌丛.     

天然牙-种植体联合支持套筒冠固定桥的临床研究

目的：研究天然牙与种植体联合支持套筒冠固定桥修复的临床疗效。方法：20例磨牙缺失患者,第二双尖牙行常规预备,第二磨牙区植入种植体,种植体端设计套筒冠固位体,完成天然牙一种植体共同支持套筒冠固定桥修复。完成修复后3、6、12、24个月定期复诊,以患者的自觉症状、天然牙和种植体的临床动度、牙周袋深度、义齿修复后种植体周围牙槽骨高度的X线片变化为观察指标。结果：20例患者在临床观察期间,行使功能良好,种植体与天然牙均动度〈1 mm,种植体与天然牙的牙周袋深度均在2mm以内。天然牙和种植体周均未见异常X线透影区。结论：天然牙与种植体联合支持套筒冠固定桥修复,在临床观察期间,成功率100%,是临床上可采用的修复方式。     

氟化泡沫和洗必泰漱口液对12岁儿童牙菌斑变形链球菌的影响

目的 观察和探讨氟化泡沫和洗必泰漱口液对于儿童牙面菌斑内的变形链球菌的影响.方法 选择80名12岁儿童分为A、B两组,每组根据DMFT的不同分为无龋组和有龋组.A组使用1.23%氟化泡沫,分别测干预前、1h、24h和1周的菌斑内变形链球菌数;而B组则使用0.2%的洗必泰漱口,测干预前和1周的菌斑内变形链球菌数.采集右上颌第一磨牙颊面的菌斑接种于MSA培养基进行细茵培养.结果 牙面菌斑内的变形链球菌数在使用氟化泡沫后1h、24h和1周均明显低于干预前水平(P<0.05);使用洗必泰漱口液漱口1周变形链球菌数也明显低于干预前水平.1周在B组的无龋组和有龋组中检出的变形链球茵数下降了57.94%和52.91%,A组中则下降了31.86%和33.77%,B组下降比例明显大于A组.结论 氟化泡沫和洗必泰漱口液都可以明显抑制儿童牙菌斑中的变形链球菌数,可作为儿童龋病预防的方法.     

慢性龈炎患者龈缘菌斑的菌群分析

目的 探讨慢性龈炎患者龈缘菌斑中菌群的变化特点及其临床应用价值.方法 选择慢性龈炎患者22例,采集44个样本,健康对照15例,30个样本,接种于选择与非选择培养基,用培养法检测总厌氧菌数、产黑色素菌群、放线菌、具核梭杆菌、口腔链球菌、变形链球菌群、乳酸杆菌菌落数及检出率,对2组菌群特点进行对比分析.结果 健康组、龈炎组的产黑色素菌群检出率分别为3％和30％,具核梭杆菌检出率分别为30％和66％,2组差异有统计学意义(P<0.01).龈炎组的总厌氧菌、产黑色素菌群、口腔链球菌、变形链球菌群、放线菌的菌落计数较健康组明显增加,有非常显著性差异(P<0.01).龈炎组的具核梭杆菌和乳酸杆菌的菌落计数比健康组增加(P<0.05).龈炎组产黑色素菌群和放线菌的构成比相对于健康组明显增加,尤其产黑色素菌群龈炎组比健康组增加200倍.结论 慢性龈炎龈缘菌斑内菌群构成比发生改变,放线菌和产黑色素厌氧菌增加,证实此2种菌群与慢性龈炎具有相关性.     

Incidence of selected ureolytic bacteria in human dental plaque from sites with differing salivary access

Saliva is the main source of urea in the human mouth and may be responsible for the predilection of ureolytic bacteria for certain tooth sites. As a test of this hypothesis, the ureolytic bacteria, Haemophilus parainfluenzae, Actinomyces naeslundii, Actinomyces viscosus and coagulase-negative oral staphylococci, were enumerated in supragingival plaque from various sites in each of 10 subjects. The sites sampled included the maxillary and mandibular incisors (chosen because the lower incisors are more exposed to the submandibular-sublingual secretion than the upper) and the maxillary and mandibular molars (the upper molars being closer to the source of parotid saliva). After dispersion of the plaque samples in saline, subsamples of each suspension were plated on appropriate selective media and other subsamples were taken for nitrogen analysis to measure the amount of plaque sampled. H. parainfluenzae that used urea was present in the largest numbers, A. viscosus was next and A. naeslundii and coagulase-negative staphylococci were least. The staphylococci and H. parainfluenzae were more numerous from mandibular than from maxillary incisors and from maxillary than mandibular molars, a pattern which suggests that salivary access favours their selection. The numbers of A. viscosus and A. naeslundii were not related to salivary access: A. viscosus was most numerous from the maxillary incisors, possibly because this site is normally the most acidic of the four studied and A. viscosus is strongly acidogenic and aciduric; the incidence of A. naeslundii had no relationship with site.(ABSTRACT TRUNCATED AT 250 WORDS)     

Identification of bacteria in association with immune components in human carious dentin

Actinomyces viscosus, A. naselundii, Streptococcus mutans serotype "c" and S. mutans serotype "d/g" were identified in human carious dentin using histological and immunofluorescent techniques. A. viscosus was most frequently found in association with patient's immunoglobulins and complement, followed by S. mutans serotype "d/g", S. mutans serotype "c", and A. naeslundii.     

The natural history of periodontal bone loss in germfree and gnotobiotic rats infected with Periodontopathic microorganisms

A new technique for evaluating the vertical component of bone loss in rats is described in which silicone base impression material is utilized. The extent and pattern of bone loss in germfree rats is compared to the bone loss in gnotobiotic animals infected with either Streptococcus mautans strain 6715 or with Actinomyces naeslundii strain I or with Actinomyces viscosus strain T 14. In general, after approximately 60 days of infection the gnotobiotic animals demonstrated patterns of bone loss similar to germfree animals although the extent of loss was more marked. The major increases in bone loss (both horizontal and vertical) were observed in the period between 60 and 90 days of infection. The major destruction offurs on the lingual aspects of maxillary molars. Vertical bone loss was greater in A. naeslundii infected animals than in S. mutans infected animals.     

Microbiology of root surface caries in humans

Studies on the microbiology of root surface caries between 1970 and 1975 placed emphasis on Gram-positive pleomorphic filamentous rods, particularly Actinomyces viscosus and Actinomyces naeslundii. Both of these species had been shown to produce root surface caries in experimental animals. Since this time, studies have placed more emphasis on Streptococcus mutans, and S. mutans and Lactobacillus are significant in prediction of root surface caries risk in patients. Subsequent studies confirmed an association between S. mutans and 'soft' or 'initial' root lesions. Thus, it is important when determining the microflora of root surface lesions to make careful characterization of the state of the lesion. A second important aspect of the analysis of bacterial communities associated with root surface caries is better definition of the organisms. Most studies have concentrated on 'target organisms' S. mutans, S. sanguis, A. viscosus, A. naeslundii, Lactobacillus, and Veillonella. However, it has been known for 17 years that the Actinomyces associated with the lesions may be variants of A. viscosus and A. naeslundii. Such strains (intermediate strains) have been described in taxonomic studies of Actinomyces, yet little is known of the differences in physiology of these strains or their relationship to root surface caries. A similar situation exists with oral Streptococcus where new taxonomic divisions are being proposed. Recognition of the potential diversity within the 'target' genera of root surface caries could yield valuable data. Recent studies suggest that this is so, since samples from root surface lesions which contain S. mutans and Lactobacillus show a high isolation of S. mitis 1 and no isolations of A. naeslundii. Careful definition of the lesions of root surface caries and the flora will allow analysis to relate a specific bacterial community to the state fo the lesion and assist in monitoring the control of the lesion through fluoride and antibacterials.     

The microflora associated with the development of initial enamel decalcification below orthodontic bands in vivo in children living in a fluoridated-water area

Thirty-four caries-free teeth destined for orthodontic extraction were banded to provide a protected area for the accumulation of plaque. The teeth were extracted at one, two, four, eight, and 14 days after being banded, and samples of the flora below the band were analyzed for the presence of Streptococcus sanguis, Streptococcus 'mitior', 'mutans streptococci', Actinomyces viscosus, Actinomyces naeslundii, Actinomyces odontolyticus, Lactobacillus species, and Veillonella. After plaque sampling, the teeth were sent to the Royal Dental College (Copenhagen) for histological analysis. The results showed that S. mutans could colonize the area below the band after one day, but that colonization was only 100% at 14 days. Lactobacillus was only isolated from 2/8 samples at four days and from 4/8 samples at 14 days. S. sanguis and 'S. mitior' were regularly isolated at all banding times, and Veillonella was isolated from all samples. A. viscosus was the most commonly isolated Actinomyces. The numbers of Streptococcus and Veillonella were significantly higher at day 1 than at day 14 (p less than 0.05). S. mutans and A. viscosus were isolated more frequently at day 14 than at day 1 (p less than 0.01). Histological examination revealed that dissolution of the enamel below a band could occur after two days, but that even after 14 days dissolution could be questionable. Dissolution was detected in areas where S. mutans was not isolated (8/34), but S. mutans was also present in samples showing dissolution (12/34). There was no relationship between dissolution and the numbers of S. mutans; however, the isolation frequency of S. mutans was associated with dissolution (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Identification of bacteria in association with immune components in human carious dentin

Actinomyces viscoxus, A. naselundii. Streptococcus mutans serotype "c" and S. mutans serotype "d/g" were identified in human carious dentin using histological and immunofluorescent techniques. A. viscosus was most frequently found in association with patient's immnoglobulins and complement, followed by S. mutans serotype "d/g", S. mutans serotype "c", and A. naeslundii .     

Effects of highly concentrated stannous fluoride and chlorhexidine regimes on human dental plaque flora

The aim of this study was to determine the effect of an intensive antimicrobial treatment on the number of Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus/Actinomyces naeslundii, and the total Colony-forming Units (CFU) in plaque. The dentition of human volunteers was treated in a dental office with either chlorhexidine (5%) or stannous fluoride (8%). Following the office treatment with chlorhexidine, selected volunteers rinsed daily at home for seven or 49 days with chlorhexidine solution (0.2%), while another group flossed daily at home for seven days with dental floss impregnated with chlorhexidine. On days one, seven, 21, 35, and 49 after the local applications, we took saliva samples and plaque samples from fissures, smooth surfaces, and approximal areas. Chlorhexidine and stannous fluoride suppressed S. mutans and the Actinomyces species on all surfaces and in saliva. S. mutans on tooth surfaces was suppressed for approximately seven days and returned to the baseline level at day 21. A. viscosus/naeslundii was suppressed for more than seven days on the teeth. S. sanguis and the total CFU returned to the baseline level within seven days on all surfaces and in saliva. Rinsing or flossing with chlorhexidine suppressed S. mutans during the period of time that these supplements were used. Brushing for seven days with chlorhexidine gel (1%) without a preceding intensive chlorhexidine treatment had virtually no effect on S. mutans in approximal areas and in saliva, but suppressed S. mutans in fissures and on smooth surfaces.     

Effect of sustained-release chlorhexidine varnish on Streptococcus mutans and Actinomyces viscosus in orthodontic patients.

This study evaluated the effect of sustained-release chlorhexidine varnish on orthodontic patients. Ten children, ages 10 to 16 years, participated. Bacterial levels of Streptococcus mutans and Actinomyces viscosus and total counts were evaluated in sputum samples. These counts were evaluated at 4 stages: before orthodontic treatment, at least 2 weeks after bonding of the brackets, 1 week after application of chlorhexidine varnish, and 3 weeks after application of chlorhexidine varnish. Increases in bacterial levels of S mutans and in the total bacterial count were detected after the brackets were bonded. One week after the sustained-release chlorhexidine varnish was applied, a significant decrease of total bacterial levels and S mutans was observed. This decrease persisted for 3 weeks after the first application. No significant change in A viscosus levels occurred during that period. The results provide additional evidence that sustained-release chlorhexidine varnish decreases S mutans levels in orthodontic patients with fixed appliances and therefore might be useful in preventing caries lesions.     

Effect of chlorhexidine gel treatment supplemented with chlorhexidine varnish and resin on mutans streptococci and Actinomyces on root surfaces

The supplementary effect of chlorhexidine varnish and resin on the reappearance of mutans streptococci and Actinomyces spp. on root surfaces after chlorhexidine gel treatment was studied. In 8 subjects with many restored tooth and exposed root surfaces, highly colonized with mutans streptococci, chlorhexidine varnish and resin were applied to the teeth on one side of the mouth and resin alone to the other side. This treatment significantly prolonged the time period of reduced salivary levels of mutans streptococci when added to a preceding period of chlorhexidine gel treatment. In 3 of the 8 subjects, mutans streptococci were undetected for more than 4 weeks after treatment. There was a significant difference between the chlorhexidine varnish/resin side and the resin side for 5 weeks with regard to the mean numbers of mutans streptococci in root surface plaque, whereas for the Actinomyces spp. no significant differences were found. In 2 subjects harboring both Streptococcus mutans and S. sobrinus, the population of S. sobrinus reappeared more readily in saliva and plaque than S. mutans. The chlorhexidine treatment was less effective in suppressing the population of Actinomyces viscosus/naeslundii than the mutans streptococci.