Interactions of sanguinarine and zinc on oral streptococci and Actinomyces species

Sanguinaria extract, which contains benzophenanthridine alkaloids, has been used as a folk medicine for many years. Minimum inhibitory and minimum bactericidal concentrations (MIC and MBC values) for sanguinarine were determined for common and etiologically important plaque bacteria. Because the efficacy of sanguinarine is believed to be enhanced by zinc, isobolograms were assessed to determine their mode(s) of interaction. Hydrogen ion concentration influenced the inhibitory activity of both sanguinarine and zinc. For sanguinarine, at the optimum pH (6.5), MIC values were 4 or 8 micrograms/ml for Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguis, Actinomyces viscosus and Actinomyces naeslundii. MIC values were 0.125-0.50 mmol Zn/ml. MBC values ranged from 1 to 8 mmol Zn/ml at pH 5.5. Isobologram data revealed that sanguinarine and zinc interacted synergistically. Viadent oral rinse, which contained 300 micrograms sanguinaria extract/ml and 0.2% zinc chloride (14.9 mmol Zn/l), was inhibitory to all strains tested. MIC values were 1 or 2% (ml Viadent oral rinse/100 ml aqueous solution) for all strains except A. viscosus for which the MIC value was 12% (vol/vol).     

In vitro inhibitory effects of Polygonum cuspidatum on bacterial viability and virulence factors of Streptococcus mutans and Streptococcus sobrinus

OBJECTIVES: Polygonum cuspidatum has been used in Korean folk medicine to improve oral hygiene. This study was performed to evaluate the effects of methanol extract from root of P. cuspidatum (MEP) on bacterial viability and the virulence factors of Streptococcus mutans and Streptococcus sobrinus. METHODS: To test the effects of MEP on bacterial viability, we determined the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) against 20 bacterial strains, including S. mutans and S. sobrinus, using a micro-dilution assay. In case of S. mutans and S. sobrinus, the assays for time-kill and bacterial growth rate at sub-MIC concentrations were also performed. To determine effects of the extract on the virulence factors of S. mutans and S. sobrinus, the assays for sucrose-dependent adherence, water-insoluble glucan formation, glycolytic acid production, and acid tolerance were performed at sub-MIC levels. Phytochemical analysis for constituents of MEP was carried out. RESULTS: MEP showed a broad antibacterial range (MIC 0.5-4 mg/ml). The MBC was two to four times higher than the MIC. The time-kill curves showed S. mutans and S. sobrinus were significantly killed after 1h of incubation. At sub-MIC levels, doubling times of S. mutans and S. sobrinus dose-dependently increased up to 211% and 123%, respectively. At sub-MIC levels, MEP also showed inhibitory effects on the virulence factors of S. mutans and S. sobrinus in a dose-dependent fashion. Phytochemical analysis revealed the presence of alkaloids, sterol/terpenes, tannins, flavonoids, and carbohydrates. CONCLUSION: These data indicate that MEP has inhibitory effects on bacterial viability at higher concentrations (> or =MIC) and the virulence factors of S. mutans and S. sobrinus at sub-MIC concentrations, suggesting that it might be useful for the control of dental plaque formation and subsequent dental caries formation.     

The in vitro effects of cetyltrimethylammonium naproxenate on oral and pharyngeal microorganisms of various ecological niches

The purpose of this study was to determine the in vitro susceptibility to cetyltrimethylammonium naproxenate for various aerobic and anaerobic micro-organisms responsible for oral and pharyngeal diseases by assessing the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) or minimum fungicidal concentrations (MFCs) and by determining kill-times. The MICs of cetyltrimethylammonium naproxenate for 46 tested strains (25 reference strains and 21 clinical isolates) ranged from 8 to 500 micrograms/ml. The MIC was found to be 31.25 micrograms/ml for 36% of the reference strains. Even lower MIC values (15.63 micrograms/ml) were observed for some anaerobic strains, for Haemophilus influenzae and for Candida tropicalis. MIC and MBC values corresponded for the majority of strains tested while the MFC for C. tropicalis and C. albicans was much higher. Only 9.5% of the clinical isolates gave a MIC value of 31.25 micrograms/ml. Enterococcus faecalis, Streptococcus pyogenes and Staphylococcus aureus showed MIC at 62.5 micrograms/ml. The MIC and MBC values among the isolates were comparable, while the MFC value for the yeasts was greater. A concentration of 125 micrograms/ml of cetyltrimethylammonium naproxenate inhibited the growth of all bacteria, except Enterobacteriaceae and Pseudomonaceae, and yeasts. Cetyltrimethylammonium naproxenate shows very rapid kill-time for S. sanguis (0"), and rapid (15") for S. pyogenes, S. dysgalactiae and S. mutans and for Moraxella catarrhalis, while a longer kill-time was necessary for the other microbes tested.     

五倍子对菌斑生物膜内细菌的抑制作用

目的:应用人工口腔观察五倍子对菌斑生物膜内细菌的抑制作用。方法:采用液体二倍稀释法测定与致龋病关系较密切的4种细菌的最小抑菌浓度,并进一步在人工口腔中形成各实验菌的单一细菌菌斑生物膜,应用菌落计数技术观察五倍子水提取物对菌斑生物膜内细菌的抑制作用。结果:五倍子水提取物对变形链球菌、粘性放线菌、血链球菌、口腔链球菌的生长均有抑制作用,其中对变形链球菌、粘性放线菌和血链球菌的最小抑菌浓度(MIC)为64mg/ml,口腔链球菌为8mg/ml;不同浓度的五倍子水提取物对各实验菌形成的单一细菌菌斑生物膜均有一定的抑制作用,并呈浓度依赖性;即使采用大于MIC的浓度,也不能把釉质表面形成的生物膜完全抑制,釉质表面仍有细菌生长。结论:五倍子水提取物对菌斑生物膜内细菌具有良好的抑制作用;与浮游细菌相比,生物膜中的细菌对五倍子水提取物具有较强的抵抗力。     

紫地榆防龋活性筛选及其防龋机制初步研究

目的:研究紫地榆各提取物防龋活性和活性成分对口腔致龋菌的增殖抑制以及产酸、产多糖功能的影响.方法:以洗必泰和五倍子作为阳性对照,采用试管二倍稀释法研究紫地榆提取物对2种主要致龋菌生长和代谢的影响,先测定紫地榆5种提取物对变形链球菌(S.mutans)、黏性放线菌(A.viscosus)的最低抑菌浓度(MIC)及最低杀菌浓度(MBC),从中筛选出防龋活性部位;再测定低于MIC的4个浓度的紫地榆防龋活性部位对2种致龋菌产酸、产多糖的影响.结果:紫地榆正丁醇萃取部位对2种致龋菌抑制效果最好,对细菌产酸、产多糖均有一定的抑制作用,但作用弱于洗必泰和五倍子.结论:紫地榆正丁醇萃取部位可抑制致龋菌生长代谢,可能是一种天然防龋药物.     

Inhibitory effect of garlic extract on oral bacteria

Garlic (Allium sativum) has long been known to have antibacterial, antifungal and antiviral properties but there are few data on its effects against oral bacterial species particularly putative periodontal pathogens or their enzymes. Filter sterilised, aqueous extract of garlic was tested for ability to inhibit the growth of a range of oral species and to inhibit the trypsin-like and total protease activity Porphyromonas gingivalis. The garlic extract (57.1% (w/v), containing 220 microg/ml allicin) inhibited the growth and killed most of the organisms tested. In general, the minimal inhibitory and minimum bactericidal concentrations for the Gram-negative strains (garlic MIC range 35.7-1.1 mg/ml; allicin mean MIC 4.1 microg/ml; mean MBC 7.9 microg/ml) were lower than those for the Gram-positive strains tested (garlic MIC range 142.7-35.7 mg/ml; allicin mean MIC 27.5 microg/ml; mean MBC 91.9 microg/ml). Also, of the organisms tested, the putative periodontal pathogens had among the lowest MICs (17.8-1.1 mg/ml garlic) and MBCs (35.7-1.1 mg/ml garlic). Time-kill curves for Streptococcus mutans and P. ginigvalis, showed that killing of the latter started almost immediately, whereas there was a delay before S. mutans was killed. The garlic extract also inhibited the trypsin-like and total protease activity of P. gingivalis by 92.7% and 94.88%, respectively. These data indicate that garlic extract inhibits the growth of oral pathogens and certain proteases and so may have therapeutic value, particularly for periodontitis.     

生物活性玻璃对致龋菌及龈上菌斑的抗菌效果研究

[摘要]目的 研究不同浓度生物活性玻璃对三种游离致龋菌,血链球菌菌斑及混合菌斑的抗菌效果。方法 测定生物活性玻璃对血链球菌、变形链球菌和粘性放线菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC),并测定pH值。37.5、75、150 mg/ml生物活性玻璃处理24 h血链球菌菌斑和48 h混合菌斑10min后,分别于场发射扫描电镜(FE-SEM)和激光共聚焦显微镜(CLSM)下摄片分析。结果 低浓度生物玻璃能够抑制细菌产酸,且pH值与空白组有显著性差异（P<0.001）。场发射扫描电镜和激光共聚焦均可见随生物活性玻璃浓度升高,细菌团块变小,层次变薄。结论 生物活性玻璃能够快速杀灭细菌,对早期的单菌种和多菌种菌斑均有一定抑制作用。在浓度较低的情况下仍能发挥一定抗菌和抗酸能力。     

Activity of amine-stannous fluoride combination and chlorhexidine against some aerobic and anaerobic oral bacteria

The in vitro susceptibility of 128 bacterial strains was tested to amine fluoride-stannous fluoride (AmF + SnF) and chlorhexidine (CHX) solutions. Actinobacillus actinomycetemcomitans, Streptococcus mutans, and Bacteroides intermedius were among the species investigated. The 50% and 90% minimal inhibitory concentrations (MICs) were assessed by an agar dilution method. The MIC ranges for A. actinomycetemcomitans were 2-32 micrograms/ml for CHX and 0.25-64 micrograms/ml for AmF + SnF. The respective values for S. mutans were 0.5-8 micrograms/ml (CHX) and 2-8 micrograms/ml (AmF + SnF); and 4-8 micrograms/ml (CHX) and 2-4 micrograms/ml (AmF + SnF) for B. intermedius. Streptococcus faecalis and Staphylococcus aureus were most resistant of the control strains (MIC 64 micrograms/ml to CHX and 32 micrograms/ml to AmF + SnF, respectively). Thus, both solutions tested exerted a definite inhibitory action on the dental plaque pathogens studied.     

Susceptibility to chlorhexidine of plaque streptococci after two years oral chlorhexidine hygiene

The purpose of the present study was to examine if streptococci, isolated from human dental plaque in experimental subjects having practiced 2 years daily oral chlorhexidine hygiene, showed any difference in susceptibility to chlorhexidine compared to plaque streptococci isolated from a control group. The minimal inhibitory concentrations (MIC) of chlorhexidine were determined using the broth dilution test tube method. From an 18 h culture of each strain in brain heart infusion, 0.2 ml were inoculated into 5 ml brain heart infusion with added chlorhexidine to final concentrations of 0, 0.5, 1, 2, 4, 8, 16, 32, and 64 μg per ml. Three months later identical tests were performed. In both tests strains of Streptococcus mutans, Streptococcus milleri and Streptococcus salivarius were found to be the most susceptible to chlorhexidine, showing MIC around 4 μg chlorhexidine per ml. Strains resembling S. milleri appeared slightly less susceptible than strains identified as S. milleri . The majority of the S. sanguis strains had MIC ranging from 8 to 16 μg per ml. This species was slightly more susceptible than a group of streptococci intermediary to S. sanguis and S. mitior , while the susceptibility of the S. mitior strains ranged from 4 to more than 64 μg per ml. A difference in susceptibility to chlorhexidine between strains isolated from the chlorhexidine group and the control group was only observed for S. sanguis . Strains of this species isolated from the chlorhexidine group showed higher MIC than did strains isolated from the control group.     

In vitro antimicrobial susceptibility of periodontopathic Actinobacillus actinomycetemcomitans to roxithromycin and erythromycin

The in vitro minimal inhibitory concentrations (MIC) and minimal bactericidal concentration (MBC) of roxithromycin and erythromycin against Actinobacillus actinomycetemcomitans were evaluated. Sixty-seven different A. actinomycetemcomitans isolated from periodontal pockets of 101 subjects with different forms of early-onset and adult periodontitis and three reference strains of A. actinomycetemcomitans (ATCC 29522, ATCC 29523, and NCTC 9710) were included in this study. Erythromycin showed poor in vitro activity against A. actinomycetemcomitans ; roxithromycin, on the contrary, exhibited good in vitro activity. Moreover, roxithromycin showed the best in vitro antimicrobial activity against 17 serotype a and 12 serotype c subpopulations of A. actinomycetemcomitans ; against 38 serotype b subpopulation of A. actinomycetemcomitans , roxithromycin was consistently active. Roxithromycin exhibited MBC values usually equal to, or onefold higher than MIC values. All the MBC values of erythromycin were three-to four-fold higher than the respective MIC result. Since roxithromycin is characterized by high concentrations in serum and good penetration and diffusion into gingival tissue, it could be expected to pass into the gingival crevicular fluid at levels sufficiently high to inhibit A. actinomycetemcomitans in vivo. These data indicate that roxithromycin might be a potential candidate for therapeutic trials in patients with A. actinomycetemcomitans -associated periodontitis.     

西帕依固龈液和没食子体外抗白色念珠菌的活性测定

目的：体外观察西帕依固龈液和没食子对白色念珠菌的作用,并对二者的抑菌和杀菌效果进行评价。方法：采用常量肉汤稀释法,检测西帕依固龈液和没食子的抑菌和杀菌效果。结果：西帕依固龈液对白色念珠菌的最低抑菌浓度（MIC）为5mg/ml,最低杀菌浓度（MBC）为10mg/ml;没食子提取液对白色念珠菌的最低抑菌浓度（MIC）为25mg/ml,杀菌浓度（MBC）为50mg/ml。结论：没食子提取液和西帕依固龈液在体外均具有一定的抗白色念珠菌活性。     

Effect of nicotine on growth and metabolism of Streptococcus mutans

Streptococcus mutans is a key contributor to dental caries. Smokers have a higher number of caries-affected teeth than do nonsmokers, but the association among tobacco, nicotine, caries, and S. mutans growth has not been investigated in detail. Seven S. mutans strains--UA159, UA130, 10449, A32-2, NG8, LM7, and OMZ175--were used in the present study. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC), planktonic cell growth, biofilm formation, metabolism, and structure (determined using scanning electron microscopy) of the seven strains treated with different concentrations of nicotine (0-32 mg ml(-1)) were investigated. The MIC, MBC, and MBIC were 16 mg ml(-1) (0.1 M), 32 mg ml(-1) (0.2 M), and 16 mg ml(-1) (0.1 M), respectively, for most of the S. mutans strains. Growth of planktonic S. mutans cells was significantly repressed by 2.0-8.0 mg ml(-1) of nicotine. Biofilm formation and metabolic activity of S. mutans was increased in a nicotine-dependent manner up to 16.0 mg ml(-1) of nicotine. Scanning electron microscopy revealed that S. mutans treated with a high concentration of nicotine a had thicker biofilm and more spherical bacterial cells. In summary, nicotine enhances S. mutans biofilm formation and biofilm metabolic activity. These results suggest that smoking can increase the development of caries by fostering increased formation of S. mutans biofilm on tooth surfaces.     

Growth-inhibitory effect of pyrophosphate on oral bacteria

The purpose of this investigation was to determine whether pyrophosphate, the anticalculus component of tartar-control dentifrices, exerts antimicrobial activity against oral bacteria commonly found in supragingival plaque. Minimal inhibitory concentrations of pyrophosphate were determined for Streptococcus sanguis, Streptococcus mutans (serotype c), Actinomyces viscosus and Actinomyces naeslundii. All of the bacteria tested were susceptible to pyrophosphate with identical minimal inhibitory concentrations of 0.67% wt/vol (25 mM). Bactericidal kinetics assays revealed that both S. mutans and A. viscosus were killed by pyrophosphate, with the latter being considerably more susceptible. The mechanism of killing was not due to high ionic strength, as comparable controls showed no loss in numbers of viable cells. Brief exposure (two 5-min incubations) of S. mutans to pyrophosphate and sodium dodecyl sulfate caused pronounced inhibition of growth over the 24-h test period. Under the constraints of the conditions used, these studies indicate that pyrophosphate and sodium dodecyl sulfate can substantially inhibit the growth of oral bacteria. These compounds may affect the oral microflora of patients who routinely use tartar-control dentifrices and mouthrinses.     

木糖醇对黏性放线菌生长及产酸影响的体外研究

目的对比不同质量浓度下木糖醇对黏性放线菌生长及产酸的影响。方法分别用含不同质量浓度（128、64、32、16、8、4 g·L^-1）木糖醇的脑心浸液（BHI）液体培养基在厌氧条件下培养黏性放线菌,测定其最小抑菌质量浓度（MIC）;然后测量对照组以及1/2、1/4、1/8 MIC和MIC质量浓度时培养1.5、3、6、12、24、48 h液体培养基的pH值,计算ΔpH值,同时测量2、4、6、8、10、12 h液体培养基的光密度（OD550）值;最后测定抑制50%及 90%黏性放线菌生物膜形成的最低木糖醇质量浓度（即MBIC50和MBIC90）。运用SPSS 19.0进行数据分析。结果木糖醇能抑制黏性放线菌的生长,MIC为64 g·L^-1。培养12 h后,各组之间的ΔpH值差异均有统计学意义（P<0.05）,且ΔpH值随MIC质量浓度的增大而减小;此时,除1/2 MIC以及MIC组之外,其余各组的OD550差异均无统计学意义（P>0.05）,OD550值随MIC质量浓度的增加而减小。提示黏性放线菌在含1/2 MIC及MIC的木糖醇培养基里生长及产酸能力随木糖醇质量浓度的升高而下降。木糖醇的MIBC50为64 g·L^-1,MIBC90为128 g·L^-1,说明木糖醇培养基能抑制黏性放线菌生物膜的形成。结论木糖醇能有效地抑制黏性放线菌的生长、黏附以及产酸,有一定的抑制致龋菌和防治龋病的效果。     

The effect of herbal extracts in an experimental mouthrinse on established plaque and gingivitis

Abstract. The purpose of the present study was to establish in vitro the inhibiting effect of a herbal extract mixture on a selected number of micro-organisms and to test in vivo the effect of a mouthwash containing 6.3 mg/ml herbal extract mixture on plaque and gingivitis as compared to a minus active control mouthrinse. The herbal extract was a mixture of: Juniperus communis (juniper), Urtica dioca (nettle), Achillaea millefolium (yarrow); 1:1:1. In the study, in-vitro, the effect of pure herbal extract mixture on acid production of Streptococcus mutans was tested and the minimum inhibitory concentrations (MIC) of the following micro-organisms were tested: Streptococcus mutans, Streptococcus mitis, Actynomyces viscosus, Actynomyces naeslundii, Actinobacillus actinomycetemcomitans, Prevotella intermedia, Campylobacter rectus, Fusobacterium nucleatum, Veillonella parvula. The MIC-values for A. viscosus and P. gingivalis were 100 mg/ml. The MIC-values for A. naeslundii and A. actinomycetemcomitans were considerably lower (10 mg/ml). S. mitis was the most susceptible of the tested organisms to the extract with a MIC value of 1 mg/ml. S. mutans, C. rectus, V. parvula, and F. nucleatum were not influenced by the extracts. No inhibitory effect of the 6.3 mg/ml herbal extract mixture was observed on the acid production of S. mutans. For the study in-vivo, 45 volunteers were selected on the basis of having moderate gingival inflammation. As efficacy parameters the plaque index, modified gingival index and angulated bleeding index were assessed. The subjects were randomly divided among 3 experimental groups (2× test and 1‘minus active’control). The participants were requested to rinse with 10 ml of mouthwash twice a day for a period of three months. After 6 weeks and 3 months, the same clinical indices as at baseline were recorded. The results show no difference between the two test groups and the control group. In conclusion, the results of the present study have shown that the mixture of the 3 herbal extracts, Juniperus communis, Urtica dioca and Achillaea millefolium when used in a mouthrinse has no effect on plaque growth and gingival health.     

Relationship of Streptococcus mutans and lactobacilli to incipient smooth surface dental caries in man.

Small samples of plaque were obtained from a number of incipient (white spot) caries lesions on buccal tooth surfaces or cavitated caries lesions on buccal and approximal surfaces. The clinically-sound tooth surface surrounding each lesion was similarly sampled. The proportions of Streptococcus mutans in samples from carious areas were significantly higher than those from the adjacent sound surface areas. Lactobacilli were not detected in samples from white spots and were recovered from only a few samples from the surrounding sound tooth surface. S. mutans preferentially colonized the gingival area of buccal tooth surfaces. The heterogeneity of dental plaque with respect to the concentrations of S. mutans was striking; 100-fold differences in concentration between samples taken from a single lesion were frequent. The recovery of S. mutans from plaque cultured on mitis-salivarius agar, supplemented with 15 per cent sucrose and 0.2 units per ml of bacitracin (MSB agar), which is selective for this organism, was generally lower than with mitis-salivarius agar without tellurite. Its recovery on MSB agar with and without tellurite was similar.     

茶多酚影响致龋菌在胶原粘附的研究

目的：研究茶多酚对致龋菌在胶原粘附的影响,进一步探讨茶多酚的防龋机制。方法：采用胶原溶液包被羟磷灰石（Ｃ－ＨＡ）形成实验性膜的体外模式,以变形链球菌、粘性放线菌和乳杆菌作为主要致龋菌,用茶多酚分别处理Ｃ－ＨＡ和细菌,观察细菌在Ｃ－ＨＡ粘附的情况。结果：在两组实验中,１～４ｍｇ／ｍｌ的茶多酚溶液都能显著抑制变形链球菌、粘性放线菌和乳杆菌在Ｃ－ＨＡ上的粘附,且抑制作用随茶多酚溶液浓度的升高而逐渐增强。     

Susceptibility of oral bacteria to Melaleuca alternifolia (tea tree) oil in vitro

The in vitro activity of Melaleuca alternifolia (tea tree) oil against 161 isolates of oral bacteria from 15 genera was determined. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) ranged from 0.003 to 2.0% (v/v). MIC90 values were 1.0% (v/v) for Actinomyces spp., Lactobacillus spp., Streptococcus mitis and Streptococcus sanguis, and 0.1% (v/v) for Prevotella spp. Isolates of Porphyromonas, Prevotella and Veillonella had the lowest MICs and MBCs, and isolates of Streptococcus, Fusobacterium and Lactobacillus had the highest. Time kill studies with Streptococcus mutans and Lactobacillus rhamnosus showed that treatment with > or = 0.5% tea tree oil caused decreases in viability of >3 log colony forming units/ml after only 30 s, and viable organisms were not detected after 5 min. These studies indicate that a range of oral bacteria are susceptible to tea tree oil, suggesting that tea tree oil may be of use in oral healthcare products and in the maintenance of oral hygiene.     

A selective medium for Streptococcus mutans

A selective medium was developed for the isolation of Streptococcus mutans from human dental plaque. Mitis-salivarius agar was modified by adding 0.2 units/ml bacitracin and by increasing the sucrose concentration to 20 per cent. At these concentrations, the selective agents allowed the undiminished recovery of Strep. mutans with maximum inhibition of the balance of the streptococcal flora normally encountered on this medium. Enterococci or yeasts were sometimes observed upon direct culturing of plaque samples from children with advanced dentinal lesions.     

二甲胺四环素胶原制剂体外抗菌研究

目的研究胶原蛋白为载体复合二甲胺四环素制成的牙周缓释制剂的抗菌效果,以期寻找辅助治疗牙周炎的新制剂。方法采用杯碟法对含20mg/g盐酸二甲胺四环素的胶原牙周缓释剂和派丽奥软膏进行牙周常见致病菌的抑菌实验,测定最小抑菌浓度（MIC）和抑菌环直径。菌珠选用国际标准菌株牙龈卟啉单胞菌、中间型普里沃氏菌、巨核梭形杆菌、伴放线放线杆菌和粘性放线菌。结果胶原牙周缓释制剂和派丽奥软膏对各实验菌株均有抑菌作用,牙龈卟啉单胞菌、中间型普里沃氏菌、巨核梭形杆菌、伴放线放线杆菌的MIC为0.31mg/L,粘性放线菌的MIC为1.2mg/L。2种药物比较抑菌效果无显著性差异（P〉0.05）。结论胶原牙周缓释制剂对牙周主要致病菌具有良好的抑制作用。