The effects of a zinc citrate dentifrice on bacteria found on oral surfaces.

PURPOSE: Clinical studies with dentifrices formulated with antimicrobial ingredients typically examine the effects of their use on clinical parameters of dental plaque and gingivitis. The effects of routine use of these formulations on the microorganisms found in the distinct regions of the human mouth remain unexplored. The present cross-over design clinical study compared the effects of brushing with a recently formulated dentifrice with 1% zinc citrate to a control dentifrice on oral bacteria found in oral niches. MATERIALS AND METHODS: A total of 35 adults completed a 1-week wash-out phase prior to providing baseline samples of dental plaque on the teeth, gums, saliva and scrapings from cheeks and tongue to quantify anaerobic bacteria. Subjects brushed twice daily with a randomly assigned test dentifrice for the next 13 days. On the 14th day, they arrived at the dental clinic prior to oral hygiene and provided samples similar to baseline samples for microbiological examinations. Subjects brushed with the test formulation they used in the previous 13 days, prior to providing additional samples at 5-h post-brushing for microbial assessments. An additional wash-out phase was assigned to subjects prior to completing the study with the alternate test dentifrice. RESULTS: Analyses of log10-transformed microbial counts indicated no statistical differences in the baseline samples from each oral site (P > 0.05), while brushing with the zinc citrate dentifrice resulted in a significant reduction in bacteria in each post-brushing oral site versus the control paste (P < 0.05). Brushing with the zinc citrate dentifrice resulted in 38.56%, 23.57%, 26.24% and 29.1% decreases in anaerobic bacteria from dental plaque, tongue, cheek and saliva, respectively, in the overnight samples collected on the 14th day versus the control. Similarly, the 5-h post-brushing samples indicated 24.8%, 34.25%, 37.98% and 38.31% reductions in anaerobic organisms when compared with control. CONCLUSIONS: Toothbrushing with the zinc citrate formulation resulted in significant reductions in oral bacteria from all of the intraoral locations.

Tooth-whitening efficacy of custom tray-delivered 9% hydrogen peroxide and 20% carbamide peroxide during daytime use: a 14-day clinical trial

OBJECTIVE: The purpose of this 14-day parallel, double blind clinical trial was to evaluate the tooth whitening efficacy of a 9% hydrogen peroxide gel (Colgate Visible White) relative to a 20% carbamide peroxide gel (Opalescence) positive control. METHODS: Forty-six consenting adults were randomly assigned to use one of the two products. All participants had 6 unrestored maxillary anterior teeth averaging a shade ranking score of 9 (A3) in the Vitapan Classical Shade Guide scale of 1 through 16 (lightest to darkest). Tooth whitening consisted of at-home 30-minute daily self-applications of the assigned product after brushing with a non-bleaching dentifrice. One of two calibrated examiners performed the baseline, 5-day, 7-day, and 14-day tooth shade evaluations for a given participant, utilizing the same Vita guide under unmodified color-corrected lighting conditions. Thirty-seven participants made all visits. Bleaching efficacy was measured with respect to mean shift (reduction from baseline) in rank scores of the maxillary anterior teeth, in which baseline rank scores functioned as covariables. RESULTS: Both treatment groups exhibited statistically significant mean shade rank score improvements from baseline after 5, 7, and 14 days at 3.14, 3.70 and 4.68 for Colgate Visible White and 1.60, 2.52 and 3.85 for Opalescence. CONCLUSIONS: Between-group comparison shows that while Colgate Visible White (9% hydrogen peroxide) provides a statistically significant tooth whitening improvement over Opalescence (20% carbamide peroxide) after 5 days of self-application, both products have a similar whitening effect after 7 and 14 days.

Individual microflora beget unique oral microcosms.

AIMS: To examine the efficacy of the multiple Sorbarod device (MSD) for the reproduction of inter-individual variations in oral microbiotas. The MSD supports sessile growth on parallel cellulose filters, perfused with artificial saliva. This enables biofilms (BF) to be grown and sampled, together with released cells in eluted medium (perfusates, PAs). METHODS AND RESULTS: Two sets of triplicate MSDs were established. One set was inoculated using fresh saliva from three separate volunteers; the second set was inoculated from one saliva donor. Both were incubated in an anaerobic cabinet. BF and PA were analysed at 24-h intervals by PCR-denaturing gradient gel electrophoresis (DGGE) of 16S rDNA. Hierarchical dendrograms were constructed in order to sort community fingerprints over time, based on community relatedness. The MSD supported complex oral communities, as evidenced by DGGE (>20 distinct DGGE bands) and confocal scanning laser microscopy. DGGE band sequencing revealed bacteriological diversity and a high incidence of anaerobic species, including Prevotella sp. Dendrograms demonstrated marked inter-individual variation in the relative species abundance within salivary inocula from different volunteers (DV) and each associated MSD (all >45%, majority c. 85% concordance). Less variation was shown between triplicate models established using saliva from a single volunteer (SV) (all >58%; majority c. 95% concordance). PAs clustered together with the associated biofilms and inocula in the majority of cases for the DV MSDs whilst SV MSD community profiles clustered between replicate MSDs. CONCLUSIONS: Data indicate that marked inter-individual variations in human salivary composition can be partially replicated in individualized MSD microcosms. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates the in vitro reproduction of individual oral microbiotas and suggests that taking inter-individual variability into account will increase the relevance of microcosm studies.

Development and characterization of a simple perfused oral microcosm.

AIMS: To validate perfused, inline, filter-based fermentation systems (multiple Sorbarod devices, MSD) for their ability to maintain stable oral bacterial communities. MSD enable replicate (n=5) microcosm biofilms (BF) to be established and sampled, together with their perfusates (PA, cells in eluted medium). METHODS AND RESULTS: Fresh saliva from human volunteers was used to inoculate MSD, incubated in an anaerobic cabinet and perfused with artificial saliva at 7 ml h(-1). BF within Sorbarod filters and cells eluted in the PA were analysed at 24-h intervals by differential bacteriological culture and checkerboard DNA-DNA hybridization (CKB, 40 oral species). Dynamic stability was apparent after 2-3 days within both BF and PA as evidenced by culture, CKB data and pH measurements. BF harboured large numbers of anaerobic species and facultative anaerobes [ca 10-11 log10 colony-forming units (CFU)/filter] comprising considerable numbers of streptococci and Gram-negative species. PA contained ca 9-10 log(10) CFU ml(-1) suggesting an apparent mean growth rate of 0.1 h(-1) for the BF, as a whole corresponding to a mean generation time of 10 h. CKB analysis revealed considerable bacterial diversity within the respective MSD. Inter-individual variations in the relative species abundance of inocula was broadly reproduced in the MSD (BF and PA), although considerable variation was apparent between triplicate models established using saliva from one saliva donor or from three individual donors. The dominance of Gram-negative species, indicated by culture was supported by CKB analysis (major species, Prevotella melaninogenica and Fusobacterium nucleatum). CONCLUSIONS: Data obtained from the various analytical approaches showed a high degree of congruence. The MSD enables the maintenance of complex, stable salivary microcosms and represents a simple, reproducible tool for modelling individual oral bacterial ecosystems. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates the utility of the MSD for studying the micro-ecology of the oral cavity.

The comparative anticaries efficacy of a dentifrice containing 0.3% triclosan and 2.0% copolymer in a 0.243% sodium fluoride/silica base and a dentifrice containing 0.243% sodium fluoride/silica base: a two-year coronal caries clinical trial on adults in Israel.

The purpose of this two-year clinical study was to provide a comparison of the anticaries efficacy associated with two commercially available, American Dental Association-accepted dentifrices: Colgate Total Toothpaste, which contains 0.3% triclosan and 2% copolymer in a 0.243% sodium fluoride/silica base; and Crest Cavity Fighting Toothpaste with Fluoristat, which contains 0.243% sodium fluoride in a silica base. The study was conducted in harmony with the published 1988 American Dental Association guidelines for studies geared toward the comparison of fluoride dentifrices. The study employed a double-blind parallel-group design, and involved adults living in communities throughout Israel. Qualifying subjects were randomly assigned to the two treatment groups, with multiple subjects in the same household all assigned to the dentifrice randomly allocated to the first among them. Caries examinations were conducted in accordance with U.S. Food and Drug Administration guidelines for the clinical evaluation of drugs to prevent dental caries. Two calibrated examiners performed all of the measurements. After treatment assignment, study participants were instructed to brush their teeth at home with their assigned dentifrice at least twice daily. Brushing instructions were reinforced by indoctrination in proper oral hygiene techniques by dental professionals, supplemented by pamphlets supplied by the sponsor and yearly mailings to participants, emphasizing good oral hygiene and the need to ensure compliance with the study. Post-baseline examinations were performed after one year of product use, and again after two years of product use. Three-thousand, three-hundred and ninety-two (3,392) subjects completed this two-year study. For these subjects, the mean caries scores (DFS, decayed or filled surfaces) at baseline were 21.96 for the Colgate Total Toothpaste group, and 21.49 for the Crest Cavity Fighting Toothpaste with Fluoristat group. For caries increment after one year, the respective means were 1.37 for the Colgate Total Toothpaste group, and 1.56 for the Crest Cavity Fighting Toothpaste with Fluoristat group. After two years, the mean caries increments were 1.46 for the Colgate Total Toothpaste group, and 1.75 for the Crest Cavity Fighting Toothpaste with Fluoristat group. No statically significant difference was indicated between the treatment groups at baseline. However, for both the one-year and two-year increments, there was a statistically significant difference between treatment groups. Relative to the Crest Cavity Fighting Toothpaste with Fluoristat group, the Colgate Total Toothpaste group presented a 12.2% reduction in caries increment scores at one year, and a 16.6% reduction in caries increment scores at two years. In accordance with the procedures and standards provided by the published guidelines of the American Dental Association for the comparison of the anticaries efficacy of fluoride dentifrices, the results of this study support the conclusion that Colgate Total Toothpaste provides a superior level of coronal anticaries efficacy compared to Crest Cavity Fighting Toothpaste with Fluoristat.

The enhanced anticaries efficacy of a sodium fluoride and dicalcium phosphate dihydrate dentifrice in a dual-chambered tube. A 2-year caries clinical study on children in the United States of America.

PURPOSE: To clinically evaluate and compare a dentifrice system in a dual-chambered tube, wherein one chamber contained sodium fluoride in a silica base and the other chamber contained dicalcium phosphate dihydrate (Test Dentifrice delivering 0.243% sodium fluoride), to a dentifrice containing 0.243% sodium fluoride in a silica base (Positive Control Dentifrice). MATERIALS AND METHODS: This study was conducted in harmony with the published 1988 American Dental Association guidelines for studies geared toward the comparison of fluoride dentifrices. This 2-yr caries clinical study employed a double-blind, parallel-group design, and involved 5-17 yr-old children from the Central and South areas of Florida and from the Lares area of Puerto Rico. Qualifying subjects were stratified according to age and sex, and were randomly assigned to the two treatment groups, with multiple subjects in the same household all assigned to the dentifrice randomly allocated to the first among them. Caries examinations were conducted in accordance with U.S. Food and Drug Administration guidelines for the clinical evaluation of drugs to prevent dental caries. Two calibrated examiners performed all the measurements. After treatment assignment, study participants were instructed to brush their teeth at home with their assigned dentifrice at least twice daily. Brushing instructions were reinforced by indoctrination in proper oral hygiene techniques by dental professionals, supplemented by pamphlets supplied by the sponsor and yearly mailings to participants, emphasizing good oral hygiene and the need to enforce compliance with the study. Post-baseline examinations were performed after 1 yr of product use, and again after 2 yrs of product use. RESULTS: Two thousand five hundred six (2,506) subjects completed this 2-yr study. For these subjects, the mean caries scores (DMFS, decayed, missing and filled tooth surfaces) at baseline were 2.29 for the Test Dentifrice group, and 2.47 for the Positive Control Dentifrice group. For caries increments after 1 yr, the respective means were 0.69 for the Test Dentifrice group and 0.81 for the Positive Control Dentifrice group. Finally, after 2 yrs, the mean caries increments were 1.25 for the Test Dentifrice group, and 1.46 for the Positive Control Dentifrice group. No statistically significant difference was indicated between the treatment groups at baseline or between the 1-yr caries increment scores. However, there was a statistically significant difference in the 2-yr caries increment scores between the treatment groups. Relative to the Positive Control Dentifrice group, the Test Dentifrice group presented a 14.38% reduction in caries increment scores at 2 yrs. In accordance with the procedures and standards provided by the published guidelines of the American Dental Association for the comparison of the anticaries efficacy of fluoride dentifrices, the results of this study support the conclusion that the dentifrice system in a dual-chambered tube, wherein one chamber contained sodium fluoride in a silica base and the other chamber contained dicalcium phosphate dihydrate, delivering 0.243% sodium fluoride, provided a superior level of anticaries efficacy than did the dentifrice containing 0.243% sodium fluoride in a silica base.

The enhanced anticaries efficacy of a sodium fluoride and dicalcium phosphate dihydrate dentifrice in a dual-chambered tube. A 2-year caries clinical study on children in Brazil.

PURPOSE: To clinically evaluate and compare a dentifrice system in a dual-chambered tube, wherein one chamber contained sodium fluoride in a silica base and the other chamber contained dicalcium phosphate dihydrate (Test Dentifrice delivering 0.243% sodium fluoride), to a dentifrice containing 0.243% sodium fluoride in a silica base (Positive Control Dentifrice). MATERIALS AND METHODS: This study was conducted in harmony with the published 1988 American Dental Association guidelines for studies geared toward the comparison of fluoride dentifrices. This 2-yr caries clinical study employed a double-blind, parallel-group design, and involved 6-10 yr-old children from the metropolitan area of Maceio, Alagoas, Brazil. Qualifying subjects were stratified according to age and sex, and were randomly assigned to the two treatment groups, with multiple subjects in the same household all assigned to the dentifrice randomly allocated to the first among them. Caries examinations were conducted in accordance with U.S. Food and Drug Administration guidelines for the clinical evaluation of drugs to prevent dental caries. One calibrated examiner performed all the measurements. After treatment assignment, study participants were instructed to brush their teeth at home with their assigned dentifrice at least twice daily. Brushing instructions were reinforced by indoctrination in proper oral hygiene techniques by dental professionals, supplemented by pamphlets supplied by the sponsor and yearly mailings to participants, emphasizing good oral hygiene and the need to enforce compliance with the study. Post-baseline examinations were performed after 1 yr of product use, and again after 2 yrs of product use. RESULTS: Two thousand four hundred thirty-two (2,432) subjects completed this 2-yr study. For these subjects, the mean caries scores (DMFS, decayed, missing and filled tooth surfaces) at baseline were 3.84 for the Test Dentifrice group, and 4.06 for the Positive Control Dentifrice group. For caries increments after 1 yr, the respective means were 2.02 for the Test Dentifrice group and 2.12 for the Positive Control Dentifrice group. Finally, after 2 yrs, the mean caries increments were 4.30 for the Test Dentifrice group, and 4.83 for the Positive Control Dentifrice group. No statistically significant difference was indicated between the treatment groups at baseline or between the 1-yr caries increment scores. However, there was a statistically significant difference in the 2-yr caries increment scores between the treatment groups. Relative to the Positive Control Dentifrice group, the Test Dentifrice group presented a 10.97% reduction in caries increment scores at 2 yrs. In accordance with the procedures and standards provided by the published guidelines of the American Dental Association for the comparison of the anticaries efficacy of fluoride dentifrices, the results of this study support the conclusion that the dentifrice system in a dual-chambered tube, wherein one chamber contained sodium fluoride in a silica base and the other chamber contained dicalcium phosphate dihydrate, delivering 0.243% sodium fluoride, provided a superior level of anticaries efficacy than did the dentifrice containing 0.243% sodium fluoride in a silica base.

Efficacy of a dentifrice containing 5% potassium nitrate and 1500 PPM sodium monofluorophosphate in a precipitated calcium carbonate base on dentinal hypersensitivity.

The effect on dentinal hypersensitivity from the use of a dentifrice containing 5.0% potassium nitrate, 1500 ppm sodium monofluorophosphate in a precipitated calcium carbonate (PCC) base over an eight-week period was compared to a placebo dentifrice without potassium nitrate. A total of forty-eight subjects were entered into the study and stratified into two balanced groups according to their baseline mean thermal (air blast) and tactile (Yeaple Probe) sensitivity scores. The two groups were randomly assigned to use either the potassium nitrate/PCC dentifrice or a placebo dentifrice without potassium nitrate. The two groups were well balanced with regard to their mean baseline thermal tactile sensitivity scores, sex and age. Subjects were instructed to brush their teeth twice daily (morning and evening) for one minute with their assigned dentifrice and a commercially available soft-bristled toothbrush. Dentinal hypersensitivity examinations, which included tactile and thermal sensitivity, were conducted at baseline, four weeks, and eight weeks. Examinations were conducted by the same dental examiner (TS) on the subjects at each examination. After four weeks' use of their assigned products, those subjects in the potassium nitrate/PCC dentifrice group demonstrated statistically significant improvements (p < 0.0001), as compared to the placebo dentifrice without potassium nitrate, in tactile and thermal sensitivity. After eight weeks' use of their assigned products, those subjects in the potassium nitrate/PCC dentifrice group again demonstrated statistically significant improvements (p < 0.0001), in tactile and thermal sensitivity, as compared to the placebo dentifrice without potassium nitrate. Thus it can be concluded from this study that the use of a dentifrice containing 5.0% potassium nitrate and 1500 ppm sodium monofluorophosphate in a precipitated calcium carbonate (PCC) base is a clinically effective method for reducing dentinal hypersensitivity.

Effect on plaque removal and gingivitis of a triclosan-copolymer pre-brush rinse: a six-month clinical study in Canada.

The effect on plaque removal and gingivitis of using a pre-brush rinse containing 0.03 per cent triclosan (Irgacare MP, Ciba-Geigy Corp.) and 0.125 per cent of a copolymer of polyvinylmethyl ether and maleic acid over a six-month period, versus using a matching placebo pre-brush rinse, was assessed in this clinical study. Subjects were instructed to rinse their mouths for one minute, twice daily (morning and evening), with 15 mL of their assigned pre-brush rinse. Immediately after rinsing, subjects brushed their teeth for 30 seconds using the dentifrice and toothbrush supplied to them at the outset. Subjects were instructed to refrain from any other oral hygiene procedures throughout the duration of the study. Plaque and gingivitis examinations were conducted after three months and again after six months. At the conclusion of the study (six months), the triclosan/copolymer pre-brush rinse demonstrated an advantage of 24.8 per cent for plaque removal and a 22.1 per cent reduction in gingivitis, when compared to the matching placebo pre-brush rinse. These advantages in plaque removal and gingivitis reduction were statistically significant. The six-month effect of the triclosan/copolymer pre-brush rinse was even greater on "the more difficult to brush" surfaces of the teeth, as determined by the use of the Plaque Severity Index and the Gingivitis Severity Index.(ABSTRACT TRUNCATED AT 250 WORDS)

Thermodontic stimulator--a new technology for assessment of thermal dentinal hypersensitivity.

A clinical investigation of the reproducibility of threshold and pain temperature scores obtained from use of the Thermodontic Stimulator (TDS) is reported. The TDS is designed for accurate clinical testing of thermal dentinal hypersensitivity. This instrument employs a variable stimulus/fixed response approach to clinical testing of thermal dentinal hypersensitivity. The TDS consists of a probe in a handpiece, a patient signaling device (joystick), a computer, and interface electronics. The TDS provides a precise means of assessing and recording the temperature which elicits a response to thermal stimulation from the subject being evaluated. Two temperatures are recorded. The threshold temperature is recorded when the patient is first able to sense that a cold stimulus has been applied to the tooth. The second score, pain temperature, is recorded when the subject first notices discomfort. Twenty-two subjects participated in this study. Results obtained from the 21 subjects who completed this study (one subject dropped out for non-compliance) demonstrated a reproducibility standard deviation of 1.1 degrees C for the threshold temperature, and 2.8 degrees C for the pain temperature for the duration of the study. There was a good degree of correlation between the measurements of any two test days (Pearson's correlation coefficient). There was no significant difference between the mean pain temperature scores of any two testing days.

Efficacy of a dentifrice containing potassium nitrate, soluble pyrophosphate, PVM/MA copolymer, and sodium fluoride on dentinal hypersensitivity: a twelve-week clinical study.

The effect on dentinal hypersensitivity from the use of a dentifrice containing 5.0% potassium nitrate, 1.3% soluble pyrophosphate, 1.5% PVM/MA copolymer, and 0.243% sodium fluoride in a silica base over a twelve-week period was compared to a matching placebo dentifrice without potassium nitrate. A total of sixty-seven subjects were entered into the study, and stratified into two balanced groups according to their baseline mean thermal (threshold) temperature (Thermodontic Stimulator) and baseline mean tactile (Yeaple Probe) sensitivity scores. The two groups were randomly assigned to use either the potassium nitrate/copolymer/pyrophosphate dentifrice or the placebo dentifrice. The two groups were well balanced with regard to their mean baseline thermal and tactile sensitivity scores, sex and age. Subjects were instructed to brush their teeth twice daily (morning and evening) for one minute with their assigned dentifrice and a commercially available soft-bristled toothbrush. Dentinal hypersensitivity examinations, which included tactile sensitivity, threshold thermal sensitivity, pain thermal sensitivity, air blast, and a visual analog scale were conducted at baseline, six weeks, and twelve weeks. All examinations were conducted by the same dental examiner. After six weeks' use of their assigned products, those subjects in the potassium nitrate/copolymer/pyrophosphate dentifrice group demonstrated statistically significant improvements (p < 0.01), as compared to the placebo dentifrice, in the following parameters: 1) tactile; 2) thermal (threshold and pain); and 3) air blast. After twelve weeks' use of their assigned products, those subjects in the potassium nitrate/copolymer/pyrophosphate dentifrice group again demonstrated statistically significant improvements (p < 0.01), in tactile, thermal (threshold and pain) and air blast sensitivity, as compared to the placebo dentifrice. It was concluded from this study that a dentifrice containing 5.0% potassium nitrate, 1.3% soluble pyrophosphate, 1.5% PVM/MA copolymer, and 0.243% sodium fluoride in a silica base is a clinically effective treatment for reducing dentinal hypersensitivity.

Comparative efficacy of two dentifrices containing 5% potassium nitrate on dentinal sensitivity: a twelve-week clinical study.

The effect of a dentifrice containing 5.0% potassium nitrate, 1.3% soluble pyrophosphate, 1.5% PVM/MA copolymer, and 0.243% sodium fluoride in a silica base (Sensitive/Tartar Control) on dentinal hypersensitivity over a twelve-week period was compared to a commercially available dentifrice containing 5% potassium nitrate and 0.76% sodium monofluorophosphate in a dicalcium phosphate dihydrate base (Sensodyne-F). A total of ninety-seven subjects were entered into the study, and stratified into two balanced groups according to their baseline mean air sensitivity score and baseline mean tactile (Yeaple Probe) sensitivity score. The two groups were randomly assigned to use either the Sensitive/Tartar Control dentifrice or the commercially available hypersensitivity control dentifrice with potassium nitrate. The two groups were balanced with regard to their mean baseline air and tactile sensitivity scores, sex and age. Subjects were instructed to brush their teeth twice daily (morning and evening) for one minute with their assigned dentifrice and a commercially available soft-bristled toothbrush. Dentinal hypersensitivity examinations, which included tactile sensitivity, cold air blast, and a visual analog scale were conducted at baseline, six weeks, and twelve weeks. All examinations were conducted by the same dental examiner. After six weeks' use of the assigned dentifrices, there were no statistically significant differences between dentifrice groups in any of the parameters assessed (tactile, cold air blast and visual analog scale). After twelve weeks' use of the assigned products, there were no statistically significant differences between dentifrice groups in any of the parameters assessed (tactile, cold air blast and visual analog scale). Thus it can be concluded from this study that the use of a dentifrice containing 5.0% potassium nitrate, 1.3% soluble pyrophosphate, 1.5% PVM/MA copolymer, and 0.243% sodium fluoride in a silica base provides a clinically effective method of reducing dentinal hypersensitivity which is comparable in efficacy to a commercially available hypersensitivity control dentifrice containing 5% potassium nitrate and 0.76% sodium monofluorophosphate in a dicalcium phosphate dihydrate base.