Modulation of Biofilm Formation and Permeability in Streptococcus mutans during Exposure To Zinc Acetate.

The penetration of biofilms by antimicrobials is a potential limiting factor in biofilm control. This is relevant to oral health, as compounds that are used to control microbial growth and activities could also affect the permeability of dental plaque biofilm with secondary effects on biofilm tolerance. We investigated the effects of zinc salts on the permeability of Streptococcus mutans biofilms. Biofilms were grown with low concentrations of zinc acetate (ZA), and a transwell transportation assay was applied to test biofilm permeability in an apical-basolateral direction. Crystal violet assays and total viable counts were used to quantify the biofilm formation and viability, respectively, and short time frame diffusion rates within microcolonies were determined using spatial intensity distribution analysis (SpIDA). While the diffusion rates within biofilm microcolonies were not significantly altered, exposure to ZA significantly increased the overall permeability of S. mutans biofilms (P < 0.05) through decreased biofilm formation, particularly at concentrations above 0.3 mg/mL. Transport was significantly lower through biofilms grown in high sucrose conditions. IMPORTANCE Zinc salts are added to dentifrices to improve oral hygiene through the control of dental plaque. We describe a method for determining biofilm permeability and show a moderate inhibitory effect of zinc acetate on biofilm formation, and that this inhibitory effect is associated with increases in overall biofilm permeability.

Increase in the level of oral neutrophils with gingival inflammation - A population survey.

Objectives: Host responses to oral inflammation include a continuous and substantive response with the influx of polymorphonuclear leukocytes (PMN). PMN, referred to as first responders, migrate rapidly from the circulatory system through the connective tissue to mitigate stimuli and localize in the saliva. This study examined the relationship between the well-established clinical indices of gingivitis and dental plaque and the PMN level. Materials and Methods: This study enrolled adults aged 18-75 years, who provided voluntary informed consent. Oral rinse samples were collected from 159 participants to estimate the PMN levels prior to the full-mouth assessment for gingivitis and dental plaque using the respective clinical indices. Results: The gingival index and dental plaque index scores were in the range of 0.098-2.71 and 0.73-4.78, respectively. Regardless of the age and gender, higher number of PMN was observed with higher gingival index and dental plaque index scores. Our analyses indicated a significant correlation between the oral PMN level and gingival index with a correlation coefficient of 0.66 (p < 0.0001). Similarly, the correlation between the PMN level and dental plaque index was statistically significant with a correlation coefficient of 0.57 (p < 0.0001). Regression analysis identified a significant relationship between the PMN level and clinical indices (p < 0.0005). Conclusions: Increase in the PMN levels with increasing clinical scores (gingival and dental plaque indices) reflect the oral inflammatory burden, irrespective of age or gender. These observations warrant future studies on participants stratified by health status and research directed toward examining the effects of interventions.

Chlorhexidine Improves Hygiene Reducing Oral Polymorphonuclear Leukocytes with Antimicrobial Effects at Distinct Microenvironments amongst Subjects Stratified by Health Status.

Oral conditions such as gingivitis and oral malodor are commonly reported globally. Objective: This investigation clinically stratified subjects to healthy, malodor and gingivitis groups and enumerated oral polymorphonuclear leukocytes (PMN) as a measure of inflammation prior to and after rinsing with a chlorhexidine (CHX) mouthwash. The study also assessed clinical outcomes (dental plaque and gingival bleeding indices), malodor (halimeter scores, organoleptic and tongue coat index and microbiological parameters (anaerobic and malodor organisms of dental plaque, tongue surface and saliva) for a comprehensive assessment of the oral inflammatory burden. Methods: Consenting adults were stratified into control (n = 17), gingivitis (n = 19) and halitosis (n = 17) groups based on clinical criteria. At baseline, oral samples were examined for PMN in addition to microbiological analysis of dental plaque, saliva and tongue scrapings for anaerobic and malodor bacteria. Subjects were issued a commercially available fluoride toothpaste and a chlorhexidine mouthwash for two-week use prior to post-treatment assessments identical to baseline. Results: At baseline, PMN were lowest in the control that increased amongst the halitosis subjects, with the gingivitis group registering the highest levels (p < 0.05) with these outcomes corresponding with clinical parameters (p < 0.05). CHX use improved outcomes with a 56−61% reduction in PMN with significant differences between groups (p < 0.05). Dental plaque and bleeding indices were lower by 57−78% with oral malodor, demonstrating reductions of 33−59% (p < 0.05). Significant reductions in anaerobic and malodor organisms ranging from 78−96% and 76−94%, respectively, were noted after CHX use (p < 0.05). Conclusions: At study enrollment, PMN scores were lowest in healthy subjects, with increasing numbers amongst halitosis followed by gingivitis. Amongst all subject groups, CHX use significantly reduced oral PMN and corroborated with corresponding decreases in clinical, malodor and bacterial outcomes. Together, these results demonstrate the significant reductions in the oral inflammatory burden following CHX use.

The Utility of Salivary Heme to Stratify Healthy Volunteers from Individuals with Gingivitis and Periodontitis: a Pilot Study.

Gingival bleeding due to poor oral hygiene is reported globally. Assessment of blood in saliva may improve diagnostics, serve as an outcome measure in clinical trials and support patient education through point-of-care tests. This work analyzed salivary heme using a rapid test format and separately using a lateral flow immunoassay assay [LF] for chair-side implementation. Clinical examinations stratified adult subjects into healthy, gingivitis or periodontitis groups at baseline. Healthy subjects presented no periodontal pockets and whole mouth gingivitis scores of less than 1.0. Gingivitis subjects registered gingival index scores greater than 1.0. Included in the periodontal disease group were subjects with periodontal pockets greater than 4 mm. The rapid test is based on the peroxidase activity salivary heme converting a colourless probe to a coloured compound for spectrophotometric analysis. For the LF assay, saliva was placed in the test window of the device with reactions scored after room temperature incubation. Average salivary heme concentrations in the healthy, gingivitis and periodontal disease groups were 27, 201 and 326 nM respectively, by the rapid test, representing significant differences by analysis of variance and Tukey's-multiple comparison tests (p<0.05). Similarly, results in the LF assay demonstrated increasing band intensity from the healthy to the periodontal disease groups and was quantifiable by image analysis. This pilot study emphasizes the potential efficacy of rapid heme measurement in investigations of oral health.

Increasing oral PMN during experimental gingivitis and its reversal by prophylaxis.

This investigation evaluated clinical parameters and the levels of polymorphonuclear leukocytes [PMN] collected in an oral rinse amongst subjects who refrained from dental hygiene for a period of 12 days. METHODS: Study enrolled consenting adults and assigned to a non-prophy group [n = 16] and a separate prophy group [n = 27]. Both groups underwent clinical evaluations and sampling for PMN at baseline and on days 3,6,9 and 12 of study initiation. The prophy group underwent supragingival prophylaxis at the conclusion of the no-hygiene phase and recalled for a final clinical evaluation and PMN assessment 1 week later. RESULTS: Progressive increases in oral PMN were noted due to abstinence from oral hygiene (p < 0.05). Subjects registered PMN increases ranging from 20% recorded three days following abstinence of hygiene to the highest value of 298% at the 12-day evaluation (p < 0.05). One week after prophylaxis, average PMN scores were 22% lower than baseline (p < 0.05). Abstinence from dental hygiene led to progressive increases in clinical parameters for dental plaque, gingival inflammation and bleeding. Dental plaque, gingival index and gingival bleeding scores recorded increases of 59%, 64% and 126% respectively at the conclusion of the no-hygiene phase. Prophylaxis resulted in marked reductions in all clinical parameters. CONCLUSIONS: Abstinence from dental hygiene corresponded with increasing scores for dental plaque, gingival inflammation and bleeding in conjunction with increasing oral PMN. These effects were irrespective of age or gender and were reversed by supragingival prophylaxis.

A randomized clinical study to examine the oral hygiene efficacy of a novel herbal toothpaste with zinc over a 6-month period.

OBJECTIVES: This clinical investigation examined the effects of brushing with a test toothpaste containing natural ingredients, that is, clove (Syzgium Aromaticum), aloe vera (Aloe Barbadensis), amla (Emblica Officinalis), neem (Azadirachta Indica), tulsi (Ocimum Basillicum) and honey (from Apis Mellifera) along with zinc salts and fluoride in comparison with a dentifrice formulated with fluoride alone on dental plaque and gingivitis over a 6-month period. MATERIALS AND METHOD: One hundred and eighty (180) subjects with mean plaque index scores greater than 1.5 (Turesky Modified Quigley Hein Plaque Index) and gingival index scores >1.0 (Loe and Silness gingival index) in good general health and who met other study criteria were enrolled in the clinical study. Subjects were evaluated for plaque and gingival index scores and were randomly assigned to perform twice-daily oral hygiene with either the test or the control toothpaste for the next 6 months. One hundred and fifty (150) subjects [test toothpaste (n = 72) and control toothpaste (n = 78)] completed the 6-month clinical study with evaluable data. Post-treatment assessments identical to baseline were conducted after 3-month and 6-month use of an assigned product after subjects refrained from oral hygiene for 12 h prior to each evaluation. Comparisons of the treatment groups with respect to baseline-adjusted gingival, plaque, and bleeding index scores at the follow-up examinations were performed using analyses of covariance (ANCOVA). All statistical tests of hypotheses were two-sided and employed a level of significance of p < 0.05. RESULTS: No significant intergroup differences were noted between treatment groups for age and gender by two-sample t-test and chi-square analyses, respectively (p > 0.05). Furthermore, the treatment groups demonstrated no differences at baseline for plaque, gingival and bleeding index scores by a two-sample t-test (p > 0.05). At 3-month and 6-month examination, the test toothpaste exhibited progressive reductions in plaque, gingival and bleeding scores as compared to control toothpaste as showed by ANCOVA (p < 0.001). In comparison with the control, the test demonstrated reductions in 23.5%, 25.6%, and 73.3% for dental plaque, gingival index and bleeding index outcomes, respectively, at the final visit. Reductions in the frequencies of sites with higher clinical scores were noted over the study with more sites registering improvements in the test group than in the control group. CONCLUSIONS: Routine oral hygiene with the test toothpaste formulated with herbal ingredients and zinc demonstrated a clinical adjunctive improvement in oral hygiene and parameters of gingival health as compared to brushing with a fluoride toothpaste.

Reductions in clinical inflammation and oral neutrophils with improving oral hygiene.

OBJECTIVE: This study compared the effects of oral hygiene with a toothpaste formulated with zinc (test) to a fluoride dentifrice (control) for effects on oral polymorphonuclear leukocyte (PMN) as a measure of whole mouth inflammation along with effects on clinical parameters of dental plaque and gingivitis. MATERIALS AND METHODS: Adults (age range 18-60 years, n = 212) completed this double-blind, parallel design study. After washout, a baseline oral rinse sample was evaluated for PMN prior to clinical assessments for gingivitis and dental plaque. Subjects were randomly assigned to brush twice daily with either the test or the control toothpaste. Post-treatment evaluations repeated all baseline assessments after 4-week, 6-week and 12-week use of dentifrice with all assessments conducted 12 hours after brushing. RESULTS: PMN reductions in the test were 16.8%, 18.7% and 42.5% at the 4-week, 6-week and 12-week evaluations respectively and significantly different from the control (p < 0.05). The test toothpaste also demonstrated progressively increasing reductions in gingivitis and dental plaque that ranged from 7.6 to 33.3% and 2.3 to 9.1% respectively versus the control (p < 0.05). CONCLUSIONS: The test dentifrice demonstrated progressive reductions in oral PMN representing whole mouth inflammation in conjunction with improvements in oral hygiene as compared to the control toothpaste. CLINICAL RELEVANCE: A hallmark of oral inflammation includes the accumulations of PMN in the afflicted gingival regions to reduce the influences of proliferating microorganisms. Brushing with a zinc dentifrice demonstrated progressive reductions in oral PMN and improvements in oral hygiene as evidenced by progressively lower dental plaque and gingival indices.

Antimicrobial effects in oral microenvironments by a novel herbal toothpaste.

OBJECTIVE: This clinical study compared the antibacterial effects after brushing with a novel herbal toothpaste incorporating zinc [test] to a control fluoride toothpaste on anaerobic organisms, gram-negative bacteria and malodor bacteria of dental plaque, tongue scrapings and cheek surfaces. METHODS: This double-blind, two-cell study enrolled 44 adults [age range 19-63 years]. Subjects completed a 1-week washout and provided baseline oral samples i.e. dental plaque, tongue and cheek scrapings for microbiological analysis. Diluted samples for microbiological analyses were plated on agar to enumerate anaerobic organisms, gram-negative bacteria and malodor bacteria representing functional groups of organisms. Subjects were randomized to brush their teeth with either the test or control with the first brushing conducted under supervision in the dental clinic. Post-treatment samples were collected 12 h after 21 day hygiene with assigned toothpaste. After providing these samples, subjects brushed in the dental clinic with additional samples collected 4 h after brushing. Statistical analyses were conducted separately for each organism collected from each oral niche by t-test for within-treatment assessments and analysis of covariance (ANCOVA) for between-treatment comparisons. RESULTS: Treatment groups demonstrated no significant differences at baseline for anaerobic organisms, gram-negative bacteria and malodor bacteria in any oral niche (p > 0.05). The test demonstrated reductions between 42 and 68% for anaerobic bacteria in oral niches, 12 h after brushing with reductions increasing to 46-80%, 4 h after brushing. Similarly, the test demonstrated reductions between 49 and 61% for gram-negative bacteria of oral niches that increased to 54-69% at the 4 h post-brushing evaluation. Reductions in malodor organisms of 22-42% were noted 12 h after brushing that increased to 60-72%, 4 h after brushing. CONCLUSIONS: In comparison to control, brushing with a novel herbal toothpaste demonstrated significant reductions in functional bacterial groups from distinct oral niches 12 h after brushing with additional microbial reductions 4 h after brushing.

The effects of a novel herbal toothpaste on salivary lactate dehydrogenase as a measure of cellular integrity.

OBJECTIVE: Lactate dehydrogenase (LDH) is a critical intracellular enzyme responsible for anaerobic respiration in pyruvate metabolism which becomes detectable in extracellular spaces after cellular breakdown. This clinical investigation examined the effects of brushing with a test toothpaste containing natural ingredients, i.e., clove (Syzygium aromaticum), aloe vera (Aloe barbadensis), amla (Emblica officinalis), neem (Azadirachta indica), tulsi (Ocimum basillicum), and honey (from Apis mellifera), and 0.96% zinc (zinc oxide, zinc citrate) and 0.76% SMFP (1000 ppm F) in a calcium carbonate base formulated with natural ingredients (Ved Shakti, Colgate Palmolive India) and a fluoride toothpaste containing 0.76% SMFP (1000 ppm F) in a calcium carbonate base (Colgate Cavity Protection, Colgate Palmolive; henceforth control) on salivary LDH in conjunction with the assessments of dental plaque and gingivitis representing oral hygiene parameters. MATERIALS AND METHODS: This double-blind, two-cell study enrolled 70 adults (age range 20-59 years). Subjects completed a washout and provided baseline saliva samples for LDH analysis and clinical assessments of dental plaque and gingivitis using the Turesky Modification of Quigley-Hein and Loe-Silness methods respectively. Subjects were randomly assigned to brush their teeth with either the test or control. Post-treatment sample collection and clinical evaluations were conducted after 3 weeks, 6 weeks, and 12 week sof brushing with all assessments conducted 12 h after hygiene. Statistical analyses were conducted independently for each parameter by t-test for within treatment evaluation and analysis of covariance (ANCOVA) for between treatment comparisons. RESULTS: At baseline, treatment groups demonstrated no significant differences for LDH or dental plaque and gingival index scores. Brushing with the test demonstrated progressive reductions in salivary LDH, plaque and gingival index scores over the study duration in comparison to the control. The test demonstrated reductions in LDH of 9.5-15.4% over the study period in comparison to the control representing statistically significant effects (p < 0.05). The test also demonstrated reductions in dental plaque that ranged between 6.4 and 16.2% over the study period and gingivitis reductions that ranged between 8.2 and 23.8% representing statistically significant results (p < 0.05). CONCLUSIONS: Brushing with a novel herbal toothpaste demonstrated significant reductions in salivary LDH representing improvements in cellular integrity with concurrent reductions in dental plaque and gingivitis as compared to the control dentifrice. CLINICAL RELEVANCE: Salivary LDH measurements offer a non-invasive and objective measurement of mucosal cellular integrity complementing other evaluations and clinical assessments such as plaque and gingival index scores.

Effects of a chlorhexidine mouthwash on clinical parameters of gingivitis, dental plaque and oral polymorphonuclear leukocytes [PMN].

Histological features of oral inflammation include infiltration of polymorphonuclear leukocytes [PMN], however studies have not examined the effects of interventions mitigating inflammation on oral PMN. Methods: This double-blind clinical study examined the effects of rinsing with mouthwashes formulated with chlorhexidine [CHX], an ingredient widely utilized in the dental clinic in comparison to a control on oral PMN representing a novel measure of inflammation. A concurrent evaluation of dental plaque and gingival inflammation using widely accepted clinical indices was included in the study. The study enrolled adult subjects providing informed consent, met study criteria and registered gingival index scores of 1.0 or more at the screening visit. Subjects [n = 90; age range 19-58 years] completed a washout phase prior to baseline evaluations for PMN and clinical assessments for dental plaque and gingivitis. Treatments [CHX or a control mouthwash] were randomly assigned to subjects for twice-daily use for the next two weeks. Post-treatment evaluations similar to baseline were conducted after one and two week use of assigned treatment. Results: At baseline, no statistically significant differences between treatment groups for PMN or clinical indices for dental plaque or gingivitis were noted. Rinsing with CHX demonstrated significant reductions for PMN and dental plaque, gingivitis in comparison to the control group. After one and two week use of CHX, PMN demonstrated a 35.9% and 54.9% reduction respectively in comparison to the control group representing significant differences [p < 0.05]. At the one and two week post-treatment evaluations, rinsing with CHX demonstrated 15% and 25% reductions in gingivitis respectively and were significantly different from the control [p < 0.05]. Rinsing with CHX also demonstrated significant reductions in dental plaque of 15% and 19% at the one and two-week post-treatment evaluations respectively in comparison to the control [p < 0.05]. The CHX group also demonstrated reductions in interproximal scores and registered the lowest frequency of gingival index or dental plaque scores on all oral surfaces. Conclusions: Results outline an objective approach to evaluate oral inflammation demonstrating a large and sustained reduction in oral PMN by CHX with these outcomes numerically higher than a clinical index evaluating gingivitis.

Visualization and Quantification of the Oral Hygiene Effects of Brushing, Dentifrice Use, and Brush Wear Using a Tooth Brushing Simulator.

Approaches that reproduce dental hygiene regimens under controlled conditions have applications in preclinical research. We have applied standardized, reproducible brushing regimes to typodonts coated in simulated or biological plaques to assess the effects on tooth cleaning of toothbrush/dentifrice regimens. Replicated typodonts were coated with OccludeTM or GlogermTM indicators to simulate plaque, and brushed reproducibly using a mechanical brushing simulator to compare the cleaning of occlusal surfaces before and after brushing with water or a dentifrice. An in vitro model using salivary inocula to cultivate oral biofilms on typodont surfaces was then developed to evaluate removal of disclosed plaque by new toothbrushes in comparison to toothbrushes with wear equivalent to 3 months of use. Analyses of typodonts brushed under controlled conditions significantly (p < 0.01) distinguished between brushed and unbrushed surfaces and between the use of water vs. dentifrice for the removal of simulated interproximal plaque (p < 0.05). New toothbrushes removed significantly (p < 0.05) more biological plaque from typodont surfaces than brushes that had been worn by repeated brushing. Through controlled and defined brushing of typodonts with simulated and biological plaques, the effectiveness of dental hygiene regimens was compared under reproducible conditions. Data indicate that the cleaning effectiveness of brushing was augmented by the addition of dentifrice and that new brushes were significantly more effective than brushes with substantial wear from previous use. Whilst we have focussed on the occlusal surfaces of molars and worn brushes, the method could be applied to a range of other tooth surfaces and oral hygiene regimens.

Antimicrobial effects of a stannous fluoride toothpaste in distinct oral microenvironments.

BACKGROUND: Clinical research has shown a relationship between microbial accumulations and oral diseases such as gingivitis and caries. The mouth harbors large densities of bacteria in distinct oral microenvironments, that is, dental plaque on teeth, saliva, and soft tissues such as the tongue, cheek, and gingiva. In this home-use study, the authors compared the effects of brushing with a newly formulated stannous fluoride toothpaste and a sodium monofluorophosphate dentifrice on bacteria of distinct oral microenvironments. METHODS: Adult participants completed a washout phase before baseline sampling of dental plaque, saliva, and scrapings from tongue, cheek, and gingiva, which were used for microbiological analysis. Treatments were randomly assigned: test (62 participants) and control (67 participants) for twice-daily toothbrushing over 8 weeks. After 4 weeks and 8 weeks, posttreatment samples 12 hours after brushing were collected for analysis. At these posttreatment visits, participants brushed in the dental clinic, and an additional sample was collected 4 hours later for microbiological analysis. RESULTS: Relative to the control, 12 hours after brushing, the test toothpaste showed greater reductions of bacteria (ranging from 14% to 27%) at the 4-week evaluation, which increased to 27% to 41% after 8 weeks of brushing. Correspondingly, 4 hours after brushing with the test toothpaste at the 4-week evaluation, there were greater reductions of bacteria in the range of 22% to 59%, which increased to a range of 33% to 61% at the 8-week assessment for participants completing the study. CONCLUSIONS: The stannous fluoride toothpaste provided bacterial reductions in all oral microenvironments 12 hours after brushing. In addition, the authors observed microbial reductions 4 hours after brushing, which increased after extended use. PRACTICAL IMPLICATIONS: The results are appropriate for oral hygiene recommendations by dental professionals.

The Effects of Two New Dual Zinc plus Arginine Dentifrices in Reducing Oral Bacteria in Multiple Locations in the Mouth: 12-Hour Whole Mouth Antibacterial Protection for Whole Mouth Health.

OBJECTIVES: To compare the effects of two new fluoride toothpastes with Dual Zinc plus Arginine to the effects of a fluoride control toothpaste in reducing bacteria in oral biofilm on teeth and in multiple soft tissue locations, as well as in saliva, 12 hours after 14 and 29 days of product use. METHODS: A randomized, single-center, three-cell, double-blind, parallel-group design was employed. The study protocol was approved by an Institutional Review Board. One hundred eighty adult subjects who met inclusion and exclusion criteria and signed an informed consent form were enrolled in the study. Subjects were randomly assigned to one of the three study products: 1) 0.96% zinc (zinc oxide, zinc citrate), 1.5% L-arginine and 1450 ppm fluoride as sodium fluoride in a silica base, Test 1; 2) 0.96% zinc (zinc oxide, zinc citrate), 1.5% L-arginine and 1000 ppm fluoride as sodium fluoride in a silica base, Test 2; and 3) 1450 ppm fluoride as sodium fluoride in a silica base, Control, for twice-daily use during tooth brushing. Oral samples were collected from the teeth, tongue, oral buccal mucosa, gingiva, and saliva at baseline and 12 hours after 14 and 29 days of assigned product use and were processed, serially diluted, plated, incubated, and scored for viable bacteria. Statistical analyses were performed separately for each sample site using ANOVA and ANCOVA for within- and between-treatment comparisons, respectively. RESULTS: One hundred seventy-three subjects completed the study. Relative to subjects in the Control group, subjects in the two Test groups exhibited statistically significant reductions of 29-41% in numbers of bacteria in each of the five sample areas, 12 hours after 29 days of product use. Similar results were seen after 14 days of product use, but some differences were not statistically significant, indicating that the effects of these zinc-based toothpastes build over time with continued use. The two Test toothpastes were shown to be clinically equivalent using the Fieller's confidence interval test. CONCLUSIONS: Toothpastes containing 0.96% zinc (zinc oxide, zinc citrate), 1.5% L-arginine and either 1450 ppm or 1000 ppm fluoride as sodium fluoride in a silica base provide statistically significant reductions in oral bacteria on the teeth, tongue, cheeks, and gums, as well as in saliva, compared to toothpaste with fluoride alone, 12 hours after 29 days of twice-daily tooth brushing. The results demonstrate that regular and continued twice-daily use of these new toothpastes provide 12-hour whole mouth antibacterial protection for whole mouth health.

Arginine Exposure Decreases Acidogenesis in Long-Term Oral Biofilm Microcosms.

Arginine is an important pH-elevating agent in the oral cavity. It has been incorporated in oral hygiene formulations to mitigate sensitivity and to prevent caries. In this investigation, the effects of sustained arginine dosing of dental plaque microcosms on bacteriological composition and pH were evaluated under controlled conditions. Plaque microcosms were established in constant-depth film fermentors (CDFFs) using salivary inocula and fed continuously with artificial saliva. To simulate resting and cariogenic states, the CDFFs were supplemented with sterile water or 5% sucrose, respectively. Plaques were then dosed twice daily with a dentifrice with 1.5% arginine arginine added (DA) or without arginine (DN). This regimen continued for over 3 weeks, after which fermentors were maintained without dosing. Microcosms were analyzed by differential viable counting, with a pH microelectrode, and by eubacterial DNA profiling. Sucrose dosing was associated with significantly (P < 0.001) decreased pH, significantly (P < 0.05) increased counts of total aerobes, Gram-negative anaerobes, aciduric species, acidogenic species, arginine utilizing species, bifidobacteria, lactobacilli and streptococci, and significant (P < 0.05) changes in DNA profiles. Plaques dosed with DA had a significantly (P < 0.001) higher pH than those dosed with DN, with or without sucrose supplementation. Dosing with DA but not DN significantly (P < 0.05) decreased counts of all functional bacterial groups apart from the total anaerobes in cariogenic plaques, and in resting plaques, dosing with DA significantly (P < 0.05) decreased counts of streptococci, lactobacilli, bifidobacteria, and acidogenic bacteria. In summary, sustained exposure of oral microcosms to arginine in formulation significantly increased plaque pH and significantly reduced the viability of cariogenic bacterial species. IMPORTANCE Arginine is used in dental health formulations to help prevent dental cavities. This study assessed the effects of the long-term dosing of laboratory dental plaques with an arginine dentifrice. Data indicate that the addition of arginine dentifrice during sucrose challenge significantly increased plaque pH, thus potentially mitigating cariogenesis. Counts of several functional groups of bacteria associated with tooth decay were significantly decreased in the laboratory plaques during exposure to the arginine dentifrice.

Reduction in bacteremia after brushing with a triclosan/copolymer dentifrice-A randomized clinical study.

AIM: The aims of this study were to; 1) test susceptibility to bacteremia in subjects with moderate gingivitis, and 2) compare the effects of brushing with a fluoride toothpaste (control) as compared to a triclosan/copolymer toothpaste (test) on those susceptible to repeated bacteremia. MATERIALS AND METHODS: One hundred and seven adult subjects were tested for repeated bacteremia after eating a hard apple. Twenty-nine bacteremia positive subjects were enrolled in a double-blind cross-over study designed to analyse the effects of a test toothpaste. After random toothpaste assignment, subjects brushed for 21 days. Following a wash-out period, subjects completed the study with the alternate toothpaste. Statistical analysis compared bacteremia between groups by analysis of covariance (ANCOVA). RESULTS: Twenty-six adult subjects completed the cross-over study. No statistically significant differences for bacteremia were seen at baseline. Mean bacterial counts at baseline and post-treatment visits were 45.5 and 10.8 counts versus 48.5 and 38.0 counts, respectively (test vs. control group; significant at p < .05). Significant reductions in blood borne bacteria were seen in the test versus control groups in both cultural and DNA data (p < .05). CONCLUSIONS: Thirty percentage of subjects showed repeated bacteremia. Brushing with a triclosan/copolymer dentifrice demonstrated significant reductions in bacteremia as compared to the control toothpaste.

Distribution of dental plaque and gingivitis within the dental arches.

Objective The natural accumulation of supragingival plaque on surfaces of human teeth is associated with gingival inflammation and the initiation of common oral diseases. This study evaluated the distribution of dental plaque and gingivitis scores within the dental arches after prophylaxis. Methods Adult subjects from the Dharwad, India area representing the general population who provided written informed consent were scheduled for screening. Healthy subjects over the age of 18 years, not currently requiring any medical or dental care, and presenting with a complement of at least 20 natural teeth were recruited for this parallel design study. Enrolled subjects (n = 41) underwent oral examinations for dental plaque (PI) and gingivitis (GI) using the Turesky modification of the Quigley-Hein and the Löe-Silness Index, respectively, at the baseline visit, followed by a whole mouth dental prophylaxis. Subjects were given fluoride toothpaste for twice daily oral hygiene for the next 30 days. Subjects were recalled on days 15 and 30 for PI and GI examinations identical to baseline. Results Analyses indicated that mean scores for PI and GI on either arch and the whole mouth were higher than 2 and 1, respectively, during all examinations. Anterior surfaces consistently exhibited lower PI scores than posterior regions of either arch, or the entire dentition. Regional GI differences within the dentition were similar to PI scores, with lower scores on anterior than posterior teeth. Prophylaxis reduced both the frequency and mean scores of both PI and GI, irrespective of arch, with lower scores observed on anterior than posterior regions during all recall visits. Molar and lingual regions consistently exhibited higher PI and GI scores compared with anterior surfaces. At all examinations, mean scores for both plaque and gingivitis were higher on approximal vestibular than mid-vestibular surfaces. Conclusions Differences observed in PI and GI within the dentition have several practical implications: (a) there are advantages of whole mouth assessments for oral health (b) a need for oral hygiene formulations to reduce the larger deposits of dental plaque in the posterior region and resultant gingival inflammation, and

Microbiological and clinical effects of an oral hygiene regimen.

OBJECTIVE: This study compared the additional effect of rinsing with a fluoride-free and alcohol-free 0.075% cetylpyridinium chloride (CPC) mouthwash to brushing alone on dental plaque, gingival inflammation, and supragingival plaque bacteria. METHODS: Adult subjects [n = 68] completed a washout period prior to baseline evaluations that evaluated gingival inflammation, gingival bleeding, dental plaque, and pocket probing depths along with microbiological analysis of supragingival plaque for bacteria. Subjects were randomized to two treatment groups: brush with fluoride toothpaste and rinse with the CPC mouthwash (test) or brush with fluoride toothpaste only (control), twice daily for the next four weeks. Subjects abstained from oral hygiene for twelve-hours prior to two-week and four-week post-treatment microbiological analysis of supragingival plaque for bacteria. Clinical assessments for gingival inflammation, gingival bleeding, dental plaque, and pocket probing depths were conducted at the four-week post-treatment visit. RESULTS: Compared to baseline, bacteria of dental plaque in the test group were reduced by 61.1% and 83.0% at the two-week and four-week evaluations, respectively (p < 0.05). Compared to baseline, bacteria of supragingival plaque in the control group were reduced by 2.3% at either post-treatment evaluations (p < 0.05). Additionally, dental plaque bacteria in the test was 69.8% and 86.8% lower than the control at the two-week and four-week evaluations (p < 0.05), respectively. After four-weeks, the test group showed 14.3% less gingivitis, 11.2% less dental plaque, 7.5% less gingival bleeding compared to the control group (p < 0.05). CONCLUSIONS: Oral hygiene comprising toothbrushing and rinsing with a mouthwash containing 0.075% cetylpyridinium chloride demonstrated greater reductions of dental plaque bacteria, improving gingival health, and eliminating supragingival plaque than toothbrushing alone.

Simultaneous Assessment of Acidogenesis-Mitigation and Specific Bacterial Growth-Inhibition by Dentifrices.

Dentifrices can augment oral hygiene by inactivating bacteria and at sub-lethal concentrations may affect bacterial metabolism, potentially inhibiting acidogenesis, the main cause of caries. Reported herein is the development of a rapid method to simultaneously measure group-specific bactericidal and acidogenesis-mitigation effects of dentifrices on oral bacteria. Saliva was incubated aerobically and anaerobically in Tryptone Soya Broth, Wilkins-Chalgren Broth with mucin, or artificial saliva and was exposed to dentifrices containing triclosan/copolymer (TD); sodium fluoride (FD); stannous fluoride and zinc lactate (SFD1); or stannous fluoride, zinc lactate and stannous chloride (SFD2). Minimum inhibitory concentrations (MIC) were determined turbidometrically whilst group-specific minimum bactericidal concentrations (MBC) were assessed using growth media and conditions selective for total aerobes, total anaerobes, streptococci and Gram-negative anaerobes. Minimum acid neutralization concentration (MNC) was defined as the lowest concentration of dentifrice at which acidification was inhibited. Differences between MIC and MNC were calculated and normalized with respect to MIC to derive the combined inhibitory and neutralizing capacity (CINC), a cumulative measure of acidogenesis-mitigation and growth inhibition. The overall rank order for growth inhibition potency (MIC) under aerobic and anaerobic conditions was: TD> SFD2> SFD1> FD. Acidogenesis-mitigation (MNC) was ordered; TD> FD> SFD2> SFD1. CINC was ordered TD> FD> SFD2> SFD1 aerobically and TD> FD> SFD1> SFD2 anaerobically. With respect to group-specific bactericidal activity, TD generally exhibited the greatest potency, particularly against total aerobes, total anaerobes and streptococci. This approach enables the rapid simultaneous evaluation of acidity mitigation, growth inhibition and specific antimicrobial activity by dentifrices.

Antibacterial efficacy of a cetylpyridinium chloride-based mouthrinse against Fusobacterium nucleatum and in vitro plaques.

PURPOSE: To assess the antimicrobial effects of a fluoride-free and alcohol-free mouthrinse containing 0.075% CPC (test rinse, TR) compared with an otherwise-identical CPC-free control rinse (CR). METHODS: Activity against laboratory cultures of Fusobacterium nucleatum, a bacterium associated with gingival disease, was determined using viable counting following 30-second exposures to TR and CR. Effects against intact saliva-derived plaque biofilms were quantified using confocal microscopy coupled with three-dimensional image analyses (viability profiling). RESULTS: Short exposures to TR caused significant inactivation of F. nucleatum, as determined by viable counting (c. 3 log reduction compared to the control rinse, P < 0.05). Confocal microscopy revealed extensive inactivation of complex oral biofilms following treatment with TR; biofilms were significantly less viable than those exposed to CR and three-dimensional images revealed extensive zones of dead bacteria even within plaque depths. In conclusion, this investigation demonstrates that the CPC-containing mouthrinse has significant antibacterial efficacy against oral bacteria associated with gingival disease and significantly inactivated plaque biofilm in comparison to a relevant control.