Effect of toothpaste rinses compared with chlorhexidine on plaque formation during a 4-day period

Abstract Evidence suggests that brushing with a toothpaste may slow plaque reformation over 24 h. This study measured the effect of toothpaste alone on plaque regrowth over a 96 h period and compared the effect with water and the known antiplaque agent chlorhexidine. At 9 a.m. at the beginning of 7,4-day no oral hygiene periods, 10 volunteers were scaled and polished. Al 5 p.m. subjects brushed their own teeth with water until plaque free. Each subject rinsed for I min with 10 ml of a randomly allocated rinse. Rinsing was repeated at 10 a.m. and 10 p.m. on subsequent days. The rinses were water, chlorhexidine 0.2% or 3 g/10 ml slurries of toothpastes containing (1) monofluorophosphate(MFP), (2) monofluorophosphate + sodium fluoride (MFP+NaF) (3) monofluorophosphate + zinc citrate (MFP+ZCT) (4) stannous fluoride (SnF₂) (5) sodium fluoride (NaF). At 16, 24, 48 and 72 h plaque on the buccal surface of the upper and lower premolars, canines and incisors was scored by the Gingival Margin Plaque Index (GMPI) and gram films of plaque samples made. At 96 h plaque was recorded diagraromatically and areas of coverage measured visually (Debris Index) and by planimetry. Progressive plaque formation to a Gingival Margin Plaque Index of 100% at 72 h was observed for toothpaste and water rinses. For chlorhexidine the Gingival Margin Plaque Index at 72 h was 6%, At 96 h plaque areas were significantly less with toothpaste rinses compared with water. Chlorhexidine very significantly reduced plaque areas compared with toothpaste and water. The bacteriological assessment of smears revealed essentially similar plaque development during toothpaste and water rinses and was consistent with previous reports. However, with chlorhexidine the densities of organisms in the smears were greatly reduced. It was concluded that the small effect of toothpaste rinses on plaque accumulation compared with chlorhexidine would not alone represent a true antiplaque effect resulting in therapeutic benefit.     

The effect of two commercial antibacterial mouthrinses on plaque growth in vivo

An experimental study was designed to compare the claimed antibacterial effect of Betadine and Blend-a-med Fluid with the known plaque growth inhibiting effect of a 0.2% aqueous solution of chlorhexidine digluconate (Hibitane). Before the test perios for 5 days. During the following week they cleaned their teeth mechanically with toothbrush and toothpicks. For the third week the students were divided into three experimental groups. Following closely the manufacturers' recommendations, one group rinsed their mouths four times daily with 10 ml of Betadine, one group every 2 hours with a glassful of water containing 5-8 drops of Blend-a-med Fluid, and the control group twice daily with 10 ml of the 0.2% chlorhexidine solution. Mechanical cleaning of the teeth was not allowed during the experimental week. The Plaque Index scorings decreased significantly from the end of the no-hygiene to the end of the mechanical cleaning period. During the experimental period a further decrease of the mean P1I scores returned to the level recorded after the no-hygiene period. As neither Betadine nor Blend-a-med Fluid proved able to prevent plaque growth in vivo, there seems to be no indication for their use in treatment of gingivitis.     

The efficacy of an anti-gingivitis chewing gum

Abstract Chlorhexidine is a well-established agent used for the control of supragingival plaque but is not without disadvantages, such as tooth staining, which limits its clinical applications to short-term use. This clinical trial studied the clinical effectiveness and stain-forming potential of chlorhexidine in a chewing gum base. Subjects (151) were screened for baseline plaque and gingival indices before receiving a dental prophylaxis and randomized into 3 treatment groups: group 1 chewed 2 pieces of chlorhexidine diacetate gum for 10 min 2× a day (total daily chlorhexidine=20 mg). group 2 chewed 2 pieces of placebo gum for 10 min 2× a day and group 3 rinsed with 10 ml of 0.2% chlorhexidine gluconate mouthwash for 1 min 2× per day (total daily chlorhexidine=40 mg). Plaque, gingivitis and stain evaluations were made at 4 and 8 weeks. Plaque and bleeding scores were significantly lower at 4 and 8 weeks in the chlorhexidine gum group compared to the placebo gum group and similar at 8 weeks to the rinse group. Stain intensity at week 8 was significantly less for the chlorhexidine gum than rinse. The staining measured by extent was also Jess with the chlorhexidine gum than the rinse, but the difference was not significant at week 4. At week 8, stain extent was significantly lower in the chlorhexidine gum group than chlorhexidine rinse. In conclusion, the results of this study demonstrate that this chlorhexidine chewing gum used with normal tooth cleaning provides similar adjunctive benefits to oral hygiene and gingival health as a 0.2% chlorhexidine rinse.     

Effect of Listerine® on dental plaque and gingivitis

abstract — The present study was performed in 10 adults in order to evaluate the effect of an antiseptic mouthrinse (Listerine®) on the rate of dental plaque formation and gingivitis development during a 2-week period when all efforts towards active mechanical oral hygiene were withdrawn. The study was performed as a crossover study and was carried out during four consecutive 2-week periods. During the first and third periods (preparatory periods) the participants were subjected to repeated professional tooth cleanings in order to establish plaque- and gingivitis-free dentitions. During the second and fourth periods (test and control periods) the participants were not allowed to brush their teeth but rinsed their mouths three times a day with Listerine or a placebo mouthwash. Plaque Index, Gingival Index, gingival fluid flow, and crevicular leukocytes were assessed on d 0, 2, 4, 7, and 14. On d 7 and 14, dental plaque was removed from the right and left jaws respectively and the wet weights determined. The chemotactic activity elaborated by the plaques was studied in Boyden chambers. During the Listerine test period, significantly lower Plaque and Gingival Index values were scored and lower amounts of plaque could be sampled in comparison to the control period.     

A methodology using subjective and objective measures to compare plaque inhibition by toothpastes

OBJECTIVES: Plaque scoring usually employs subjective indices. The aim was to compare plaque inhibition of three toothpastes using two objective and one subjective measures of plaque. MATERIAL AND METHODS: Formulations were: (1) an experimental anti-plaque paste (test); (2) an experimental paste (minus active or negative control); and (3) a proprietary anti-plaque toothpaste product (positive control). The study was a blind, randomised crossover design using a 4-day, no tooth brushing, plaque regrowth model and involving 22 healthy subjects. After baseline plaque removal, subjects rinsed twice a day with slurries of the allocated paste. On day 5, plaque was scored by index, wet weight and optical density of extracted disclosing solution from the plaque (stain intensity). RESULTS: All data showed the same pattern. There were highly significant subject and treatment effects but not period effects. The positive control was highly significantly more effective in plaque control than the test and minus active experimental formulations, which in turn were not significantly different from each other. There were strong and significant correlations between pairs of scoring methods particularly wet weight and stain intensity. CONCLUSION: The use of objective methods of plaque alongside conventional subjective indices provided convincing evidence for increased discriminatory power in a study comparing plaque inhibition by toothpastes.     

pH responses to sucrose and the formation of pH gradients in thick 'artificial mouth' microcosm plaques.

Artificial microcosm plaques were grown in a five-plaque culture system for up to 6 weeks, reaching a maximum depth of several mm. Procedures for long-term pH measurement with glass electrodes were established; they showed that the application of 5 or 10% sucrose for 6 min with a slow continuous flow of a basal medium containing mucin (BMM) generated the pH changes characteristic of in vivo Stephan curves. These pH responses were reproducible between plaques. Plaque mass and thickness were critical variables. Successive, sucrose-induced pH curves in plaques up to 4 mm thickness showed minor reductions only in the amplitude and rates of pH change. In plaques over 4 mm thick there was a pronounced reduction in pH response to successive sucrose applications, indicating increased diffusion limitations--a result of plaque growth to seal in the freshly-inserted pH electrode. In plaques of 6 mm maximum thickness, 10% sucrose induced a decrease to below pH 5.5 lasting 24 h, compared to the pH response in 2 mm thick plaque, which returned to the resting pH in 2 h. Differences in pH of up to 0.9 units were identified in thick plaques between inner and outer layers. The BMM flow rate was a critical determinant of the amplitude of the pH response to sucrose and subsequent return to resting pH. These results confirm, for microcosm plaque, the importance of clearance dynamics and diffusion-limited gradients in regulating plaque pH.     

Optimal dosage of chlorhexidine digluconate in chemical plaque control when applied by the oral irrigator

Abstract Chlorhexidine digluconate for chemical plaque control was tested in different concentrations using a fractionated jet oral irrigator. The inhibition of plaque formation and the prevention of gingival inflammation were evaluated in a double-blind study. During a 10-day period of abstinence from any mechanical oral hygiene procedures, the pattern of plaque formation and gingivitis development under the influence of chemical plaque control was analyzed. As a positive control, one group rinsed twice daily with 30 ml of a 0.2% chlorhexidine solution while a group applying 600 ml of a placebo solution served as a negative control. Forty dental students and assistants with plaque-free dentitions and healthy gingival tissues were divided into four groups. After a 10-day period of no oral hygiene, a recovery period of 11 days with perfect oral hygiene was again instituted. This experiment was repealed three times so that a total of 10 concentrations in the irrigator, the control rinsing and the placebo control could be evaluated. Daily application of 600 ml of a 0.001%(6 mg), 0.0033% (20 mg), 0.005% (30mg), 0.01% (60 mg), 0.02% (120 mg), 0.05% (300 mg) and 0.1% (600 mg) and 400 ml of a 0.015 % (60 mg), twice 400 ml of a 0.015% (120 mg) and 400 ml of a 0.02% (SO mg) solution of chlorhexidine was tested. At the start of each experimental period (day 0), after 3, 7 and 10 days and 11 days following reassuming oral hygiene procedures, the plaque accumulations were determined using the Plaque Index System (Silness & Löe 1964) and the development of gingivitis was evaluated according to the criteria of the Gingival Index System (Löe & Silness 1963). The results suggested that one daily irrigator application of 400 ml of a 0.02 % chlorhexidine solution was the optimal and lowest concentration and dose to be used for complete inhibition of dental plaque.     

The effect of dentifrices containing zinc citrate on plaque growth and oral zinc levels

Zinc salts have previously been shown to possess antiplaque activity in solution but this activity has as yet not been reported for dentifrices. The purpose of the present investigation was to establish the effect of dentifrices containing zinc citrate (ZCT) on plaque growth and on the concentration of zinc in saliva and plaque. Plaque growth inhibition was studied over periods of time approximating to intervals for normal oral hygiene procedures. Zinc in saliva and plaque was measured by atomic absorption spectroscopy. Elevated zinc levels in saliva were observed for 3-4 h after brushing with the zinc citrate dentifrice. Similarly, raised levels of zinc were encountered in plaque 1 h following contact with a slurry of a dentifrice containing ZCT. Increased concentrations of zinc were observed in plaque fluid and plaque residue. The plaque growth data from 88 participants in 5 studies revealed that plaque regrowth over 16 h or 22 h was reduced by dentifrices containing 0.5% ZCT, compared to placebo dentifrices. Dentifrices which contained 0.5% ZCT or 0.4% stannous fluoride, had similar inhibitory effects on plaque. Further analysis of the data showed that subjects with high rates of plaque growth benefited more from the zinc dentifrices than those with low rates of plaque growth. It is suggested that the effect on plaque was related to zinc concentration in the dentifrice rather than total dose applied, and that the main effect of zinc was to inhibit the extension of existing plaque.     

Effect of a combination of copper and hexetidine on the acidogenicity and copper accumulation in dental plaque in vivo

A double-blind crossover study on 4 adult volunteers was performed to evaluate the effect of hexetidine on Cu2+ accumulation in dental plaque as well as a possible enhanced effect of copper on inhibition of acid production in the presence of hexetidine. The experimental period was 5 days. No oral hygiene was allowed, and sucrose-containing chewing gum was used to enhance plaque formation during the test period. In order to evaluate the effect on pH, the test persons rinsed with a 15% glucose (w/v) solution on the 5th experimental day. Plaque pH values recorded before and 5 min after the rinse served as control values. One hour later the test persons rinsed with 10 ml of the test solutions for 1 min. Glucose rinses with pH measurements 5 min after the rinse were carried out 0, 3, and 7 h after the test agents were used. The combination of 1.0 mM copper and 2.0 mM hexetidine gave a significant (p less than 0.05) inhibition of acid production at all times compared both to the controls and to each of the test agents separately. Plaque samples were collected with a toothpick immediately before a 1-min rinse with 10 ml of the test solutions. Subsequent plaque samples were taken 5 min and 3 and 8 h after a rinse from corresponding tooth surfaces. Dry weight was estimated, the plaque bacteria digested by HNO3, and the amount of Cu2+ determined by atomic absorption.(ABSTRACT TRUNCATED AT 250 WORDS)     

The comparative effect of acidified sodium chlorite and chlorhexidine mouthrinses on plaque regrowth and salivary bacterial counts

Abstract Acidified sodium chlorite (ASCI is recognised as a highly potent, broad spectrum antimicrobial system that has been successfully developed for uses in veterinary, food processing and medical device fields. The current studies aimed to investigate the persistence of antimicrobial action and plaque inhibitory properties of 3 ASC mouthrinses by comparison with positive control, chlorhexidine 0.12%, and placebo control, water, rinses. Both studies were randomised, double-blind, cross-over 5-cell designs balanced for carryover. The 1st study involved 15 healthy subjects who immediately before and at 30, 60, 180, 300 and 420 min after rinsing provided 2 ml saliva samples. The samples were immediately processed for total anaerobic bacterial counts recorded after 96 h incubation. Washout periods were a minimum of 3 days. The second study involved 20 healthy subjects who on day 1 of each study were rendered plaque free, suspended normal oral hygiene methods and commenced rinsing twice daily with the allocated rinse. On day 5, plaque was scored by index and area after disclosing with erythrosin. Washout periods were 2 1/2 days. The 3 ASC and chlorhexidine rinses produced similar reductions in salivary bacterial counts which remained significantly below the placebo control to 7 h. There were no significant differences between ASC and chlorhexidine rinses except at 30 and 60 min when significantly greater reductions were produced by 2 ASC rinses compared to the chlorhexidine rinse. Plaque indices and areas were considerably and significantly lower with the ASC and chlorhexidine rinses compared to the placebo rinse. There were no significant differences between plaque scores for the 3 ASC rinses and the chlorhexidine rinse, although for 2 ASC rinses plaque scores were lower than for the chlorhexidine rinse. The results indicate that the 3 ASC rinses have equivalent plaque inhibitory action to chlorhexidine as a rinse. Similar to chlorhexidine. the plaque inhibitory action of the rinses appears to be derived from a persistence of antimicrobial action in the mouth.     

The mechanism of action of chlorhexidine

Controversy exists concerning the mode of action of chlorhexidine in plaque inhibition. This study attempted to determine whether an oral reservoir of chlorhexidine was necessary for plaque inhibition. Plaque growth on enamel under the influence of topically applied or rinsed chlorhexidine was closely monitored by clinical scoring, bacterial culturing and scanning electron microscopy. Thus, 3 subjects wore removable acrylic appliances containing enamel inserts. In the first regimen, inserts on one side of the appliances were exposed to 0.2% chlorhexidine and on the other, water for 1 min twice a day for 14 days. In the second regimen, subjects rinsed with 0.2% chlorhexidine for 1 min twice a day for 14 days with the appliances in situ. Results demonstrated that plaque growth assessed by the 3 study methods was very small on chlorhexidine-treated inserts by comparison with water-treated specimens. Importantly, inserts treated with chlorhexidine topically or by rinsing could not be distinguished by any method of evaluation. It is concluded that chlorhexidine achieves plaque inhibition as a result of an immediate bactericidal action during the time of application and a prolonged bacteriostatic action as a result of adsorption to the pellicle coated enamel surface. Consistent with other clinical studies, it is apparent that a progressively desorbing oral reservoir of antiseptic is not the mechanism by which chlorhexidine achieves plaque inhibition on teeth.     

Assessment of the effect of dentifrices on the growth of dental plaque

Abstract A new technique for assessing the effects of dentifrices on the growth of human dental plaque is described. Laboratory personnel brushed their teeth with the dentifrices and a new plaque index, the Gingival margin Plaque Index, was used to measure plaque growth over the next 16 hours. The index estimates the proportion of the length of the buccal gingival margin in contact with disclosed plaque on the surface of each tooth. Dentifrices containing 0.4, 0.8 and 1.2% chlorhexidine digluconate caused a lower plaque growth than a placebo paste. The differences were highly significant (P < 0.001). The size of the reduction depended on the concentration of chlorhexidine in the dentifrices. The disclosing reagent had no major effect on plaque growth. The coefficient of linear correlation between results from two examiners was 0.89 for the measurement of plaque growth. Dentifrices containing a quaternary ammonium salt also reduced plaque growth.     

A comparison of the plaque-inhibitory properties of stannous fluoride and low-concentration chlorhexidine mouthrinses

BACKGROUND: Plaque inhibition by chlorhexidine (CHX) rinses is dose related with a relatively flat dose-response curve above 5-6 mg twice daily. Low dose regimens could therefore reduce local side effects but maintain reasonable efficacy. AIMS: To compare the plaque inhibitory properties of two low-dose CHX rinse products with more conventional levels delivered from proprietary rinses. A secondary outcome was a comparison with a stannous fluoride/amine fluoride (SFAF) rinse product. METHODS: The study was a five-treatments, negative controlled, randomised, single blind crossover design balanced for residual effects, involving 20 healthy subjects in a 24-h plaque re-growth model. On day 1 of each study period, subjects were rendered plaque free, suspended tooth cleaning and followed the appropriate rinse regimen. On day 2, subjects were scored for plaque by index and area. The rinse codes and rinsing regimens were: (A) 15 mg CHX 2 x daily for 30 s (0.1% CHX), (B) 9 mg CHX 2 x daily for 60 s (0.06% CHX), (C) 10 ml SFAF rinse 1 x daily for 30 s, (D) 15 ml placebo 2 x daily for 60 s, and (E) 6 mg CHX 2 x daily for 30 s (0.06% CHX). RESULTS: Average mouth plaque indices and areas were highly significantly different between rinsing regimens. All test rinses were significantly more effective than the placebo rinse. There was a mean dose-response pattern for the CHX rinses, but there were no statistically significant differences between any of the test rinses. CONCLUSIONS: Lower doses of chlorhexidine in rinses can be used to exert plaque inhibition comparable with products used at higher doses and equivalent to benchmark products such as the SFAF rinse. However, the availability of chlorhexidine from formulations has to be considered as in part explaining the results.     

Approximal brush head used on a powered toothbrush

AIM: This study was designed to test whether the approximal efficacy of a powered toothbrush (Braun Oral-B 3D Plaque Remover) can be improved when a pointed-shaped brush head (PBH) specifically designed for these approximal areas is used as compared with the standard cup-shaped brush head (CBH). MATERIAL AND METHODS: Forty non-dental students were included. They all received the powered toothbrush and two different brush heads (CBH+PBH). Instructions were given to use each brush head twice every day (2 min. with the CBH followed by 1 min. with the PBH). Two weeks later they received an appointment for the first experiment (Exp 1), prior to which they abstained from all oral hygiene procedures for 48 h. Plaque was assessed at 6 sites/tooth. Next, the dental hygienist brushed for 2 min. (30 s/quadrant) with the CBH. Plaque was scored again. Subsequently, the dental hygienist brushed the approximal areas for another minute: in two randomly selected contra-lateral quadrants for 30 s with the CBH and in the opposing quadrants for 30 s with the PBH. The next approximal plaque was scored a third time. After 2-3 weeks, Exp 2 was carried out comparable to Exp 1; only this time the panelists brushed themselves. RESULTS: Exp 1 showed approximal plaque scores at the baseline of 1.70 and 1.72 and at post-brushing 0.21 and 0.26 for the CBH + PBH and CBH only, respectively (p<0.05). The additional increase in approximal plaque reduction after 30 s of brushing with PBH was 22% and for the CBH 19% (p<0.05). Exp 2 showed approximal plaque scores at baseline of 1.76 and 1.74 and post-brushing of 0.21 and 0.24 for the CBH+PBH and the CBH, respectively. The additional approximal plaque reduction of 30 s brushing with PBH was 19% and 18% with the CBH (no significant difference). DISCUSSION/CONCLUSION: An additional 1 min. showed minor differences (1-3%) between brush heads. The effect of the 1 min. extra brushing (+/-18%) itself was much larger. It seems therefore beneficial to advise the patient to brush longer. A second different brush head may stimulate to do so.     

A comparison of 4 techniques for clinical detection of early plaque formed during different dietary regimes

The purpose of this study was to evaluate the sensitivity of 4 clinical techniques used in detecting early plaque during a period of dietary sucrose restriction and during a period of sucrose supplementation. The accumulation of plaque during experimental periods of 3 h, 6 h and 18 h was recorded in a group of 38 dental personnel for the 1st part of the study, and in a group of 32 for the 2nd part. Plaque levels were assessed using a caries probe, a plaque detection probe, erythrosin and a 2-tone disclosing agent. There was a progressive increase in plaque over the period of the study, with significant variation between the detection methods used and the sites being assessed. Plaque formed more rapidly interdentially and on the posterior teeth. 3 h after the teeth had been thoroughly cleaned, plaque was detectable on over 12% of sites for the sucrose-restricted diet and on up to 23% of sites for the sucrose-supplemented diet. After 18 h of plaque formation, the proportion of plaque-covered surfaces had increased to between 52% and 73%. For minimal amounts of plaque, the disclosing solutions were found to be the most sensitive assessment techniques. However, for moderate and abundant plaque deposits, the techniques using the probes resulted in a greater degree of differentiation in the proportional measurements of plaque. Overall, the plaque probe was found to be as sensitive or better than the other techniques under most conditions and was favoured on clinical grounds, as it aided access to the interdental areas and provided a contrasting colour at the tip to enable plaque to be detected with greater ease.(ABSTRACT TRUNCATED AT 250 WORDS)     

Studies on the effect of polyvinyl pyrrolidone on the activity of chlorhexidine mouthrinses: plaque and stain

BACKGROUND, AIMS: Polyvinyl pyrrolidone (PVP) was shown in vitro to reduce chlorhexidine induced, dietary staining without affecting the uptake of the antiseptic to the test substrate. The aim of these studies in vivo was to determine whether PVP affected plaque and dietary staining by a low concentration chlorhexidine rinse. METHODS: The plaque and stain studies used a double blind, randomised 6, treatment crossover design involving healthy subjects with a high standard of oral hygiene and gingival health. The rinse formulations under test were: (A) aqueous alcohol (placebo control), (B) 0.03% chlorhexidine, (C) 0.06% chlorhexidine, (D) 0.06% chlorhexidine+1.2% PVP, (E) 0.06% chlorhexidine+5% PVP, (F) 0.06% chlorhexidine+10% PVP. In the plaque study, on day 1 of each period, subjects were rendered plaque free and then rinsed with 15 ml of the test rinse for 60 s. No further tooth cleaning was performed and subjects returned 24 h later for plaque scoring by area. In the stain study, on day 1 of each period, the tongue and teeth of each subject were rendered stain free. Subjects then rinsed under supervision for 60 s with 15 ml of the allocated rinse 8 x a day between 09:00 h and 17:00 h for 3 days. Immediately after each rinse with the test formulation, subjects rinsed for 120 s with 15 ml of warm black tea. Subjects were requested to also drink at least 5 cups of tea or coffee per day. On day 4, stain was scored by area and intensity from designated teeth and dorsum of the tongue. Washout periods were at least 7 days in both studies. RESULTS: Plaque areas were greatest with placebo and least with 0.06% chlorhexidine. Plaque scores increased with increasing concentrations of PVP in the 0.06% chlorhexidine rinse and were significantly higher than 0.06% chlorhexidine without PVP rinse. Tooth stain areas were comparable for placebo, 0.03% and 0.06% chlorhexidine rinses, but significantly reduced with the PVP/chlorhexidine rinses compared to the 0.06% chlorhexidine rinse. Tooth stain intensity was significantly increased with 0.06% chlorhexidine rinses compared to placebo and chlorhexidine/PVP rinses. Tongue stain area and intensity were significantly reduced with 5% and 10% PVP/chlorhexidine rinses compared to 0.06% chlorhexidine rinse. CONCLUSION: PVP, at the concentrations tested, reduced the stain propensity of a 0.06% chlorhexidine rinse but at the expense of some loss of plaque inhibition.     

Inhibition of plaque formation and plaque acidogenicity by zinc and chlorhexidine combinations

Abstract – Zinc ions and chlorhexidine (CH) were found to exhibit a synergistic inhibitory effect on in vitro growth of S. sobrinus OMZ 176 and of S. sanguis 10556. A clinical mouthrinsing experiment was performed in a group of 10 volunteers to assess the plaque-inhibiting capacity of this combination. Sucrose enhanced plaque accumulations were assessed (Plaque Index, Silness & Löe) after 4 days of twice daily mouthrinses with 10 ml aqueous solutions of either 10.0 mM zinc or 0.55 mM CH, or with a combination of zinc ions and CH, during which period no mechanical toothcleaning was performed. The Zn–CH combination showed improved inhibition properties compared to the individual agents. The effects on plaque acidogenicity of 8.0 mM zinc, 0.44 mM CH, and of zinc and CH in combination were also assessed in a test panel of five volunteers. The Zn–CH combination inhibited acid production by dental plaque significantly (P< 0.05) more than the individual agents 1 h 30 min after a single rinse.     

Efficacy of an amine fluoride-triclosan mouthrinse as compared to the individual active ingredients

BACKGROUND: The purpose of the clinical study was to examine the antibacterial and plaque-reducing properties of mouthrinses containing triclosan (TRI), amine fluoride (AmF), and the combination of both (AFT) on 4-day plaque regrowth. A placebo solution (PLA) and a 0.2% chlorhexidine solution (CHX) served as negative and positive controls, respectively. MATERIALS AND METHODS: After a professional tooth cleaning (day 0), 15 volunteers refrained from all mechanical oral hygiene measures for the next 96 h and rinsed instead twice daily for 1 min with 10 ml of one of the five randomly assigned solutions. Plaque index (PlI), which was assessed after 24 and 96 h (PlI1, PlI2), and plaque area of the front teeth (PA), which was planimetrically recorded from disclosed teeth after 96 h, served as clinical parameters. After 24 and 96 h a plaque sample was taken and analyzed microbiologically to evaluate biofilm vitality (VF1, VF2). The subsequent test cycles were conducted after a washout period of 10 days each. RESULTS: No severe adverse events or allergy were seen during the study. CHX influenced all parameters at all time points in comparison to PLA. AFT and AmF showed very similar values (in all parameters), but AmF did not reach the level of significance regarding VF1, nor did AFT with VF2 and PlI1. The TRI solution only reduced PlI2 and PA significantly, but had no influence on biofilm vitality when compared to PLA. CONCLUSION: A synergism between AmF and TRI was not observed. The results suggest that the plaque-reducing and antibacterial effects of the AFT solution are mainly based on the effects of the amine fluoride moiety.     

Clinical study to compare the effect of stannous fluoride and chlorhexidine mouthrinses on plaque formation

Abstract A clinical study was conducted on four adults to compare the relative efficacy of 0.2% chlorhexidine digluconate and 0.1 % stannous fluoride (SnF₂). Using a crossover experimental design, subjects rinsed twice daily for 5 days with SnF₂ and then, after a 2-day interim recovery period, for 5 days with chlorhexidine. Statistically significant differences (P < 0.05) in the relative efficacy of the two agents were found. Chlorhexidine was more effective in reducing Gingival and Plaque Indices, plaque wet weight and bacterial Colony Forming Units, calculated both per subject and per group.     

Effect on de novo plaque formation of rinsing with toothpaste slurries and water solutions with a high fluoride concentration (5,000 ppm)

The aim of this study was to evaluate the effect, on de novo plaque formation, of rinsing with toothpaste slurries and water solutions containing a high concentration of fluoride (F). Sixteen subjects rinsed three times per day for 4 d with dentifrice slurries containing 5,000, 1,500, and 500 ppm F, while 12 subjects rinsed with water solutions containing 5,000, 1,500, 500, and 0 ppm F, and 1.5% sodium lauryl sulphate (SLS). Plaque was scored [using the Quigley & Hein index (QHI)] after each 4-d period. Plaque samples for F analysis were collected. Significantly less plaque was scored for the dentifrice slurry containing 5,000 ppm F (buccal and all surfaces) and for 1.5% SLS (buccal surfaces). The differences in plaque scores between dentifrice containing 5,000 and 1,500 ppm F were 19% for all surfaces and 33% for buccal surfaces. The difference between the water solutions containing 1.5% SLS and 1,500 ppm F for buccal surfaces was 23%; the corresponding difference for 5,000 ppm F was 17%. The dentifrice slurry containing 5,000 ppm F accumulated 56% more F in plaque. The combination of high levels of F and SLS in dentifrice reduces de novo plaque formation and increases the accumulation of F in plaque after 4 d.