The samples of dental deposit plaque collected from 30 people in the faculty of Natural Science were stained by Gram technique. A bacterial prosperious component was detected including Gram (+) cocci, Gram (-) cocci, red and thin cell, red and long cell, straight and curved Gram (-) cells, thin spinal cells … Microorganism population on the deposit plaque under the gun includes bacteria, cocci, and spirochaetes. 3 genera were determined including Streptococcus, Lactobacillus and Actinomyces, with a highest incidence of Streptococcus. The representative genus has the characteristic similar to Streptococcus mutans and it seems that it plays an important role leading to caries
Dental Plaque ; Bacteria ; Dental Care

BACKGROUND AND OBJECTIVE: The role of dental plaque as the etiology of caries and periodontal diseases has long been established. Therefore, plaque control is central to the prevention and management of these oral diseases. Among the different means of self-performed plaque control, brushing is the most essential. Moreover, toothpaste is a common adjunct during tooth brushing, as its abrasive contents are believed to enhance plaque removal. This study aimed to compare the effectiveness of plaque removal when brushing with a sodium bicarbonate abrasive-containing toothpaste, compared to brushing using an abrasive-free toothpaste.

METHODS: Twelve students from the University of the Philippines College of Dentistry participated in the study. The subjects discontinued all oral hygiene measures for a minimum of 48 hours. Using the Modified Bass technique, they performed tooth brushing for two minutes, using either an abrasive-free or abrasive containing toothpaste. Toothpaste allocation was randomized via fishbowl method. Pre-brushing and post brushing plaque scores were recorded using the Turesky modification of Quigley-Hein plaque index. A washout period of 11 days was implemented before crossover to the second round, wherein employed toothpastes were switched. The difference in plaque reduction between the two kinds of toothpaste was analyzed using Wilcoxon signed rank test.

RESULTS AND CONCLUSION: Overall plaque reductions were 75% for the abrasive-free toothpaste and 73% for the abrasive-containing toothpaste. The difference between the toothpaste was statistically insignificant (p=0.48). Therefore, based on the study, brushing with a sodium bicarbonate abrasive-containing toothpaste resulted in similar levels of plaque removal, compared to brushing with an abrasive-free toothpaste. There is insufficient evidence that abrasives in toothpaste result in more effective dental plaque removal. 

OBJECTIVETo compare the periodontal indices and Porphyromonas gingivalis (P. gingivalis) between the use of self-ligating brackets and conventional brackets.

METHODSThirty patients were divided into 2 groups(n=15). Self-ligating brackets were used in the experimental group. Conventional brackets were used in the control group. Clinical periodontal indices, including plaque index (PLI), gingival index (GI) and probing depth (PD) of observed teeth were examined at three different time points: Before orthodontic treatment, the first month after treatment and the third month after treatment. Subgingival plaques were collected simultaneously at each time point. The number of total bacteria and P. gingivalis in each sample were detectd and quantitated by real-time quantitative polymerase chain reaction, the percentage of P. gingivalis in total bacteria was obtained.

RESULTSBefore treatment, the periodontal indices and the percentage of P. gingivalis in total bacteria had no difference between the two groups (P>0.05). After 1 and 3 months respectively, the periodontal indices and the percentage of P. gingivalis in total bacteria increased with time (P<0.05) and were obviously lower than those of the control group (P<0.05).

CONCLUSIONCompared with conventional brackets, the self-ligating brackets are better for periodontal health. But it is adverse effect on oral health.

OBJECTIVES: The aim of this study was to compare Plaque Percent Index (PPI), calculated by Patient Hygiene Performance Index (PHPI), Rustogi's modification of the Navy Plaque Index (RMNPI), and the Quigley & Hein Plaque Index (QHPI), with visual assessment. METHODS: Ninety-six subjects, aged between 30–65 years, were examined; twenty subjects were included in the final analysis. The subjects' teeth were stained and photographed. Dental coloring and intraoral camera photography were performed by a single examiner. The oral images obtained were analyzed using Image J to measure the area of dental plaque. The values of PHPI, RMNPI, and QHPI were calculated twice. Statistical analyses were performed using descriptive statistics, chi-square test, and Pearson's correlation coefficient. RESULTS: The results of the correlation analyses of PPI with PHPI, QHPI, and RMNPI were as follows: for PHPI, the correlation coefficient (r)=0.584; for QHPI, r=0.689; and for RMNPI, r=0.729. Further, the kappa indices of PHPI, QHPI, and RMNPI were 0.810, 0.677, and 0.590 respectively. CONCLUSIONS: Among RMNPI, QHPI, and PHPI dental plaque indices, RMNPI and QHPI showed a high degree of correlation with the actual stained dental plaque area; on the other hand, PHPI showed the highest kappa index.
Dental Plaque Index* ; Dental Plaque* ; Hand ; Humans ; Hygiene ; Photography ; Tooth

OBJECTIVETo establish determination method of formic acid, lactic acid, acetic acid and succinic acid in dental plaque with high performance liquid chromatography (HPLC).

METHODSAfter the samples were centrifuged, 2 microL supernatant was transferred to a 1 mL centrifuge tube and diluted in water, then was determined with HPLC. The mixture of phosphate buffer and methanol (97:3) as mobile phase throughout the experiment. The determination of organic acid was performed on Phenomenex C18 column and at their maximum absorption wave.

RESULTSThe linear ranges of formic acid, lactic acid, acetic acid and succinic acid were 0.110-500, 0.049-500, 0.047-500, 0.084-500 microg/mL. The detection limits were 0.110, 0.049, 0.047, 0.084 microg/mL. The relative standard derivation were 9.5%, 7.9%, 4.3%, 4.2%. The average recoveries of samples were 82%-112%, 82%-102.5%, 90%-115%, 80%-110%.

CONCLUSIONThe method was simple, quick and adapt for analysis of organic acid in dental plaque.

Dental plaque is structurally a kind of biofilm which contains a variety of micro-organisms. The interreaction of oral micro-organisms may affect the nature, forms, and toxicity of the dental plaque biofilm, as well as the localization and field planting of bacteria inside the biofilm. The signal transduction existed between the bacterium has an important effect on the formation and virulence of bacterial biofilm. This reviewing paper focuses on the latest research progress of human oral microbial community and dental plaque biofilm.
Bacteria ; Bacterial Adhesion ; Biofilms ; Dental Plaque ; Humans

The purpose of this study was to evaluate the effectiveness of gargling solution with 0.05% NaF and 10% Xylitol in orthodontic patients with fixed appliance. The sample consisted of 20 patients who were classified into an experimental group and a control group, 10 patients each. Experimental group was used experimental gargling solution and the control group was used with placebo solution. The results were as follows. 1. There were significant reduction in the number of S. mutans C.F.U. between pre and post 3 weeks(p<0.01), 9 weeks(p<0.05) in experimental group. 2. There were significant reduction in the ration of S. mutans C.F.U. to total C.F.U between pre and post 3, 6, 9 weeks(p<0.01) in experimental group. 3. S. mutans, which were reduced until 3 weeks, did not show significant change after 3, 6, 9 weeks. 4. S. mutans were strongly suppressed until 3 weeks after gargling solution with 0.05% NaF and 10% Xylitol.
Dental Plaque* ; Humans ; Streptococcus mutans* ; Streptococcus* ; Xylitol

OBJECTIVETo investigate the aciduric bacteria in different stages of the fissure caries in order to determine potential roles of the microflora in the development of dental caries.

METHODSPlaque samples were taken from 10 incipient carious fissures of the first permanent molars. Plaque samples were also collected from sound fissures of the first permanent molars in 10 other subjects who kept caries free over the past 2 years and from the above 10 subjects. The predominant bacteria were isolated by using both the most probable method in media at pH7.0 and 5.2, and the conventional plating methods. Streptococcus spp. was identified by means of API 20 Strep commercial kit.

RESULTSS. mutans was the predominant aciduric bacteria infissures of caries-free children and more frequently recovered at neutral pH. Whilst, S. sanguis was predominant at pH5.2 in sound and carious of fissures of caries-active children. The proportion of Gram-positive rods at pH5.2 was 82%, significantly greater than that of 61% at pH7.0.

CONCLUSIONThe ecology of plaque is complex and the composition of microflora at each stage of caries could be different. The composition of bacteria was consistent with the changes of local pH in the plaque.

OBJECTIVETo study the effect of methylene blue on the growth and acid production of Streptococcus mutans, and the effect of methylene blue on acid production metabolism in plaque glycolysis model (i-PGM) in vitro, and investigate the practicability of methylene blue as a new kind of dental caries prevention agent.

METHODSNephelometer method was used to measure OD value of Streptococcus mutans culture fluid in the different incubation conditions. The kinds and quantities of acid produced by Streptococcus mutans in the different incubation conditions were measured with gas chromatography. pH values of glycolysis buffer media of i-PGM in the different treatment conditions were measured by ORION electrode.

RESULTS(1) The OD value of Streptococcus mutans treated by methylene blue was lower than that by normal saline, and there was significant statistical difference between them. (2) The kinds of acid in three different culture fluid were same, but the total quantities of acid were significantly different among three different culture fluid, in which the total quantities of acid of culture fluids treated by glucose was the greatest, and treated by methylene blue was the lest. (3) The pH value of i-PGM treated by methylene blue was significantly different compared with negative control group, but was not significantly different compared with positive control group.

CONCLUSIONMethylene blue can inhibit the growth and acid production metabolism of Streptococcus matans and acid production metabolism of i-PGM.

OBJECTIVETo detect and distinguish Streptococcus mutans (S. mutans) and Streptococcus sobrinus (S. sobrinus) quickly in epidemiology and investigate the distribution of S. mutans in the oral of children with rampant caries.

METHODSDesigned minor groove binder (MGB) probes according to the gtf gene of S. mutans and S. sobrinus. Detected 9 reference strains of Streptococcus mutans group by MGB probes in real time and after cultivation. Evaluated the results of these two methods. 92 dental plaques from pre-school children with rampant caries were detected in real time with MGB probes.

RESULTSThe primers could amplify the target sequences specificity and distinguished S. mutans and S. sobrinus from each other using MGB probes. Though the fluorescence occurred earlier in S. mutans than in S. sobrinus, they had the same results in nature. In 92 children with rampant caries, the detective ratio of S. mutans was 96.7% and that of S. sobrinus was 32.6%. All the samples which could detect S. sobrinus were positive for S. mutans.

CONCLUSIONThe primers and probe designed from gtf genes of S. mutans and S. sobrinus can amplify the target sequence and distinguish them from each other in real time.