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Objectives: To investigate the neutralising effects of subsequent urea rinse on sucrose-induced decrease in plaque pH with interdental plaque pH telemetry., Method: Six participants wearing partial lower prostheses which incorporated a miniature glass pH electrode were included. After 5 or 6 days of plaque accumulation on the tip of the electrode, the subjects rinsed with a 15 ml 10% sucrose solution, followed by no subsequent rinsing or rinsing with either 15 ml of water, 0.25%, 0.50% or 1.00% urea solution, for 2 min. The plaque pH was continuously recorded for 120 min., Results: Without subsequent rinsing, the plaque pH decreased at 10 min to 4.39 and stayed below the critical pH of 5.7 for 80 min following a sucrose rinse. Subsequent water rinse showed little effects on the sucrose-induced decrease in plaque pH, whereas subsequent urea rinses all immediately and effectively neutralised sucrose-induced decrease in plaque pH, and remained above the critical pH of 5.7 until the end of data collection., Conclusion: Urea rinse could effectively counteract the pH fall following sucrose administration. These results strongly suggested that the regular use of low-concentration urea rinse after carbohydrate consumption may help prevent caries.

Increasing the concentration of free fluoride in oral fluids is an important goal in the use of topical fluoride agents. Although sodium lauryl sulfate (SLS) is a common dentifrice ingredient, the influence of this ion on plaque fluid and salivary fluid fluoride has not been examined. The purpose of this study was to investigate the effect of SLS on these parameters and to examine the effect of this ion on total (or whole) plaque fluoride, an important source of plaque fluid fluoride after a sufficient interval following fluoride administration, and on total salivary fluoride, a parameter often used as a surrogate measure of salivary fluid fluoride. Ten subjects accumulated plaque for 48 h before rinsing with a 12 mmol/l NaF (228 µg/g F) rinse containing or not containing 0.5% (w/w) SLS. SLS had no statistically significant effect on total plaque and total saliva fluoride but significantly increased salivary fluid and plaque fluid fluoride (by 147 and 205%, respectively). These results suggest that the nonfluoride components of topical agents can be manipulated to improve the fluoride release characteristics from oral fluoride reservoirs and that statistically significant change may be observed in plaque fluid and salivary fluid fluoride concentrations that may not be observed in total plaque and total saliva fluoride concentrations.

The purpose of this study is to determine whether a calcium (Ca) prerinse used before a 228 µg/g (ppm) fluoride (F) rinse would induce the formation of 'calcium fluoride-like' (CaF2-like) deposits in human dental plaque. Sixty minutes after the use of the Ca prerinse/F rinse, plaque samples were collected from 10 volunteers, homogenized, and split into 2 aliquots. The plaque mass from one aliquot was then extracted with a 'plaque-like' solution that extracted all the CaF2-like deposits. The total F in both aliquots was then determined and compared. The results demonstrated that, as in previous studies, the Ca prerinse induced large increases in plaque fluid and total plaque F. However, unlike previous results without the Ca prerinse, 30% of the plaque F deposits were CaF2 or CaF2-like. Given that maintaining an elevated F concentration in the vicinity of a developing lesion may play an important role in the cariostatic effect of this ion, and the potential advantages of CaF2-like deposits as an F source, these results suggest that a Ca prerinse may increase the cariostatic effect of topical agents.

The main objective was to investigate whether low-molecular-weight fraction of edible mushroom shiitake extract (Lentinus edodes) possesses caries-preventive properties. The study was designed as a double-blind, three-leg, cross-over, randomized, controlled clinical trial carried out on two series of volunteers at the University of Gothenburg, and the Academic Centre for Dentistry Amsterdam. Volunteers rinsed twice daily with a solution containing low-molecular-weight fraction of edible mushroom, placebo (negative control without active ingredients), or Meridol (positive control, AmF-SnF(2)) for two weeks, with a two-week washout period between each rinsing period. Changes in the acidogenicity of dental plaque before and after a sucrose challenge, shifts in microbial composition, and plaque scores were determined. Frequent rinses with shiitake reduced the metabolic activity of dental plaque. No reduction of plaque scores and no inhibition of the production of organic acids in plaque was found. Minor differences in microbial composition between test sessions were found. To conclude, the results indicate that shiitake extract has anticariogenic potential, but not to the same extent as the positive control.

Objectives: Studies concerning side effects of chlorhexidine as related to the presence of plaque are scarce. The purpose of this study was to compare the side effects of 0.12% chlorhexidine gluconate (CHX) on previously plaque-free (control group) and plaque-covered surfaces (test group)., Methods: This study had a single-blind, randomized, split-mouth, 21 days-experimental gingivitis design, including 20 individuals who abandoned all mechanical plaque control methods during 25 days. After 4 days of plaque accumulation, the individuals had 2 randomized quadrants cleaned, remaining 2 quadrants with plaque-covered dental surfaces. On the fourth day, the individuals started with 0.12% CHX rinsing lasting for 21 days. Stain index intensity and extent as well as calculus formation were evaluated during the experimental period., Results: Intergroup comparisons showed statistically higher (p<0.05) stain intensity and extent index as well as calculus formation over the study in test surfaces as compared to control surfaces. Thus, 26.19% of test surfaces presented calculus, whereas calculus was observed in 4.52% in control surfaces., Conclusions: The presence of plaque increased 0.12% CHX side effects. These results strengthen the necessity of biofilm disruption prior to the start of CHX mouthrinses in order to reduce side effects.

The aim of this in vivo study was to evaluate the effect of two antimicrobial mouthrinses on dental plaque acidogenicity after a sucrose challenge. Twenty subjects, with a mean age of 59 years, participated in a double-blind intraindividual randomized study. Three mouthrinses were used in 16-day rinsing periods in addition to their regular mechanical oral hygiene: a solution with essential oils (EO), solution with alcohol-free chlorhexidine (CHX) and water (negative control). The three test periods were separated by 3-month washout periods. Changes in plaque acidogenicity were evaluated after a sucrose challenge at day 0 (baseline) and at day 17 of each mouthrinse period using the microtouch method. Both CHX and EO resulted at day 17 in statistically significant less attenuated pH falls compared to the water rinse. The CHX mouthrinse resulted in the least pronounced pH values compared with EO (ns) during the whole 30-min period. When calculated as area under the curve (AUC), significantly lower values (AUC(6.2) ) were found for CHX and EO at day 17 compared to day 0. A significant difference for AUC(6.2) between CHX and water was found at day 17. No statistically significant differences were found for any of the comparisons with AUC(5.7). The results from this study indicate that both the essential oils and the alcohol-free chlorhexidine reduced plaque acidogenicity after a sucrose challenge. Large interindividual variations were observed.

Plaque 'calcium-fluoride-like' (CaF(2)-like) and fluoride deposits held by biological/bacterial calcium fluoride (Ca-F) bonds appear to be the source of cariostatic concentrations of fluoride in plaque fluid. The aim of this study was to quantify the amounts of plaque fluoride held in these reservoirs after a sodium fluoride rinse. 30 and 60 min after a 228 microg/g fluoride rinse, plaque samples were collected from 11 volunteers. Each sample was homogenized, split into 2 aliquots (aliquots 1 and 2), centrifuged, and the recovered plaque fluid combined and analyzed using microelectrodes. The plaque mass from aliquot 1 was retained. The plaque mass from aliquot 2 was extracted several times with a solution having the same fluoride, calcium and pH as the plaque fluid in order to extract the plaque CaF(2)-like deposits. The total fluoride in both aliquots was then determined. In a second experiment, the extraction completeness was examined by applying the above procedure to in vitro precipitates containing known amounts of CaF(2)-like deposits. Nearly identical fluoride concentrations were found in both plaque aliquots. The extraction of the CaF(2)-like precipitates formed in vitro removed more than 80% of these deposits. The results suggest that either CaF(2)-like deposits were not formed in plaque or, if these deposits had been formed, they were rapidly lost. The inability to form persistent amounts of CaF(2)-like deposits in plaque may account for the relatively rapid loss of plaque fluid fluoride after the use of conventional fluoride dentifrices or rinses., ((c) 2010 S. Karger AG, Basel.)

Background and Objective: Dental calculus occurs as a consequence of supersaturation of saliva with respect to calcium phosphates. This mineralization of dental plaque can be delayed by the presence of crystallization inhibitors, such as pyrophosphate or bisphosphonates. Phytate inhibits brushite and hydroxyapatite crystallization and has the potential to prevent dental calculi formation. The aim of the present study was to examine the effects of phytate and zinc, administered in a mouthwash solution, to prevent the formation of dental calculus., Material and Methods: Healthy dental plaque-forming volunteers (n = 25) took part in a randomized, double-blind, three-period crossover clinical study to assess the efficacy of a phytate-containing mouthwash in relation to control and placebo effects. Subjects rinsed their mouths for 1 min, twice each day, with 20 mL of the test solution, without ingestion. Mouthwash efficacy was assessed through quantification of the amounts of calcium, phosphorus and magnesium present in the residues obtained by dental cleaning, performed by a single trained examiner., Results: A good correlation was found among total calcium, magnesium and phosphorus in calcified dental plaque residues, indicating that any of these variables is adequate for evaluating the reduction of plaque crystallization as calcium phosphate. A statistically significant decrease in total calcium, magnesium and phosphorus was found in the phytate-treatment period compared with control and placebo periods, demonstrating the efficacy of the proposed treatment in reducing dental calculus formation., Conclusion: The high efficacy of phytate in reducing dental calculus formation suggests that this substance may be an effective treatment for preventing the development of calculus deposits.

Purpose: The aim of this in situ double-blind randomised crossover study was to investigate the effect of calcium (Ca) pre-rinse on the composition of plaque and on enamel prior to the use of fluoride (F) dentifrice., Materials and Methods: During four phases (14 days each) of this study, 10 volunteers had agreed to wear dental appliances containing two healthy bovine enamel blocks. A fresh solution containing 20% weight/volume (w/v) sucrose was dripped on the enamel blocks ex vivo for 5 min three times a day. Subsequently, the appliances were replaced in the mouth, and the volunteers rinsed their mouth with 10 mL of a Ca (150 mmol/L) or a placebo rinse (1 min). In sequence, a slurry (1:3 w/v) of F (1030 ppm) or placebo dentifrice was dripped onto the blocks ex vivo for 1 min. During this time, the volunteers brushed their teeth with the respective dentifrice. The appliances were replaced in the mouth, and the volunteers rinsed their mouth with water. The plaque formed on the blocks was analysed for F and Ca. The enamel demineralisation as well as the incorporation of F on enamel was evaluated by cross-sectional microhardness and alkali-soluble F analysis, respectively. Data were tested using analysis of variance (P < 0.05)., Results: The Ca pre-rinse prior to the use of the F dentifrice led to a three- and sixfold increase in the plaque F and Ca concentrations, respectively. It also did not have any additive effect on the F content on the enamel and the demineralisation of the enamel, in comparison with the use of F dentifrice alone., Conclusions: A Ca lactate rinse used prior to the F dentifrice was able to change the mineral content in the plaque, but it was unable to prevent enamel demineralisation.

In this study, the effects of 0.2% sodium fluoride mouthwash solution on calcium, phosphate and fluoride ion contents of saliva and microbial plaque was assessed. Fourteen volunteer students (7-12 years of age) of a boarding educational centre in Kerman City (Iran) were selected and under defined conditions, their saliva and plaque samples were collected. The concentrations of fluoride, calcium and phosphate ions of the samples were determined, and after 14 days, under the same conditions, the students were asked to rinse their mouth with 0.2% sodium fluoride mouthwash solution. The second set of saliva and plaque samples were collected and the concentrations of the ions were determined. Data was analyzed using paired t-test and the results were presented as tables. P < 0.05 was considered as statistically significant. After using 0.2% sodium fluoride mouthwash solution, a significant increase was observed in the F 2 ion concentration both plaque ( P P < 0.000) of all the studied subjects, while the concentration of phosphate decreased in both saliva and plaque; however, this decrease was significant only in plaque ( P < 0.01). The calcium ion concentration decreased in both plaque and saliva; however, in none of them, the decrease was significant ( P> 0.09 and P> 0.2, respectively).

The aim of this study was to document changes in plaque pH when an acidic challenge was followed by rinsing with miswak extract (Salvadora persica), and to evaluate the effect of miswak rinse on parotid gland secretion rate. Plaque pH was measured in 3-day-old plaque using the microtouch electrode. Rinsing with miswak extract, compared with water rinsing, resulted in protracted elevation of plaque pH (>6.0). The difference in plaque pH between miswak extract and water rinse was statistically significant at 30 min (p < 0.001). Rinsing with miswak extract stimulated parotid gland secretion (p < 0.01). In conclusion, miswak extract raised the plaque pH, suggesting a potential role in caries prevention., ((c) 2007 S. Karger AG, Basel)

Plaque fluoride concentrations ([F]) are directly related to plaque calcium concentrations [Ca]. Attempts to increase plaque F uptake from dentifrices or rinses have used methods designed to increase plaque [Ca] but with inconsistent results. This double-blind, double-crossover study tested the effect of a 150 mM calcium lactate rinse used prior to brushing with placebo or fluoridated dentifrices (1030 p.p.m. as NaF) on plaque and salivary [F] and [Ca]. Sixteen children (8-10 yr of age) were randomly assigned to four different groups according to the four treatments (placebo dentifrice or fluoridated dentifrice preceded by calcium lactate or deionized water prerinses). Plaque and saliva were collected 1 and 12 h after brushing on day 7 after starting to use the dentifrices. F was determined using the electrode and Ca was determined using atomic absorption spectrometry. Plaque and salivary [Ca] were not significantly increased after use of the calcium lactate prerinse, except for plaque [Ca] 1 h after the use of the placebo dentifrice. A significant increase in salivary [F] was associated with the calcium lactate prerinse only at 1 h after the use of the fluoridated dentifrice. The the calcium lactate prerinse did not significantly affect plaque [F] under any condition.

The aim of the present study was to assess fluoride concentrations in unstimulated saliva and buccal dental plaque 6 h after an oral hygiene procedure that consisted of brushing with an AmF/SnF2 dentifrice and different post-brush rinsing protocols: expectorating the excess of dentifrice foam and rinsing with tap water, expectorating only, or rinsing with 10 ml AmF/SnF2 mouthwash. The fluoride concentrations in plaque and saliva were increased after all three experimental protocols compared to F-free periods. The increase of the fluoride concentration in saliva was more pronounced after AmF/SnF2 mouthrinse as compared to rinsing with water and expectorating the excess of dentifrice foam. Such an effect was not seen in dental plaque. It is concluded that the potentially beneficial effect of not rinsing or fluoride rinsing after tooth brushing is not reflected in an increased fluoride concentration in newly formed dental plaque 6 h after brushing., (Copyright 2006 S. Karger AG, Basel.)

This study was carried out to examine interindividual differences in salivary variables related to plaque accumulation and to estimate their influence on the fluoride retention in plaque in vivo by a mineral-enriching solution. Two saliva samples were taken from 10 subjects, once after brushing and once after 24 h without brushing. Calcium, phosphate and monofluorophosphatase (MFPase) activity in the saliva samples were determined. The salivary flow rate and the debris index were also recorded. After plaque had formed over 3 days within in situ plaque-generating devices, subjects were instructed to rinse with a mineral-enriching mouthrinse three times a day on 4 consecutive days. Plaque exposed to distilled water plus flavoring agents served as a control. Fluoride-free dentifrice was used during the experimental period. Twenty-four hours after the last rinsing, the samples were removed from the mouth, and fluoride and mineral distributions in plaque analyzed using a method previously reported by the authors. Salivary flow, MFPase activity and calcium concentration in saliva were significantly higher after 24 h of plaque accumulation. Rinsing with the mineral-enriching solution produced retention of fluoride and phosphate in the outer and middle layers of plaque. Salivary calcium concentration had a direct effect on fluoride uptake in plaque, but no obvious relationship was found between other salivary variables and the plaque fluoride retention. The salivary calcium effect may be due to enhanced bacterial cell wall binding of fluoride via calcium bridging., (Copyright 2002 S. Karger AG, Basel)

The purpose of this study was to examine plaque and saliva composition after a fluoride rinse and subsequent sucrose application. Fifteen subjects accumulated plaque for 48 h, and then rinsed with a fluoride rinse based on 228 microg/g (ppm) Na2SiF6 and some received no rinse. After 60 min, upper and lower buccal molar plaque samples and 1-min saliva samples were collected. The subjects then rinsed with 10% g/g sucrose solution, and 7 and 15 min later, a second and a third set of samples were collected. Plaque fluid and clarified saliva were then recovered from these samples by centrifugation, and the remaining plaque acid extracted. The plaque fluid, centrifuged saliva, and plaque extract samples were then analyzed using micro techniques for pH, free calcium, phosphate, organic acids (plaque fluid and saliva only) and fluoride. Considering both the fluoride rinse and no-rinse groups, the most notable compositional changes in saliva 7 min after the sucrose rinse were pH -0.40 unit, free calcium 0.42 mM, lactate 5.2 mM, phosphate -1.3 mM, and fluoride 2.8 microM; while in plaque fluid, the corresponding changes were pH -1.59 unit, free calcium 1.5 mM, lactate 35 mM, phosphate -1.6 mM and fluoride -26 microM. After sucrose rinsing, undersaturation was found with respect to dicalcium phosphate dihydrate in saliva and plaque fluid and with respect to tooth enamel in some plaque fluid samples. Plaque fluid composition appeared to be strongly influenced by salivary clearance, diffusive loss of ions into the water phase of the rinse, and lower jaw pooling of the sucrose and fluoride components of the rinses. After the experimental rinse, the fluoride concentration in plaque fluid [86 +/- 22 mM (upper molar site), 162 +/- 150 mM (lower molar site)], saliva (26 +/- 18 mM), and whole plaque [99 +/- 97 microg/g (upper molar site), 197 +/- 412 microg/g (lower molar site)] was comparable to the values in previous studies using this rinse. These very high plaque fluid fluoride concentrations, compared with the 'no-rinse' samples, induced an approximately 0.3-unit increase in the plaque fluid pH 7 min after the sucrose rinse, a small decrease (approximately 20%) in lactate production and a modest increase in enamel saturation. Although these changes were all statistically significant, no correlation was found between the decrease in lactate concentration and plaque fluid fluoride, pH or whole plaque fluoride., (Copyright 2002 S. Karger AG, Basel)

Objective: An important determinant of the anticaries effect of brushing with a fluoride dentifrice is the retention of fluoride in the oral fluids. This study measured the influence of various post-brushing rinsing routines on fluoride retention., Setting: The Faculty of Odontology, Göteborg University, Sweden., Subjects: Twenty-one healthy dental students, aged 23 +/- 2 yr., Design: A randomised, cross-over protocol, comparing various post-brushing rinsing procedures, with the following variables: volume of rinsing water (5 mL vs. 10 x 3 mL) and duration of rinsing (10 vs. 60 s). Samples of whole saliva, interdental fluid and interdental plaque were analysed for fluoride content., Results: The duration of rinsing did not influence fluoride retention in whole saliva, interdental fluid or interdental plaque. Rinsing with a higher volume of water substantially decreased fluoride retention in all samples., Conclusion: Brushing with a fluoride dentifrice should be followed by rinsing procedures which enhance the retention of fluoride. Rinsing with large volumes of water decreases fluoride retention in the oral fluids, and should be discouraged.

Labile reservoirs are important in maintaining ion concentrations in oral fluids, especially after a fluoride dentifrice application, where a persistent increase in fluid fluoride can mitigate or reverse caries progression. In this study, the effect of experimental and conventional fluoride rinses on the in vitro and in vivo water-induced release of fluoride, calcium, phosphate, acetate and hydrogen ions from oral reservoirs was examined. At the start of each experiment, 13 subjects rinsed either with a conventional 228-ppm fluoride NaF rinse, a 228-ppm fluoride controlled-release rinse (CR rinse) or received no rinse. Sixty minutes later upper and lower molar plaque samples and 1-min saliva samples were collected. The subjects then rinsed with deionized water for 1 min, and 7 min later, a second set of samples was collected (in vivo study). Plaque fluid and clarified saliva were then recovered from samples by centrifugation, and the remaining plaque mass was sequentially extracted with water and acid to measure the water-extracted and total whole-plaque fluoride (in vitro study). All the samples were analyzed using microtechniques for pH, free calcium, phosphate, organic acids (plaque fluid) and fluoride (plaque fluid, centrifuged saliva and plaque extracts). Results showed that in vivo water rinsing decreased acetate and phosphate in plaque fluid, and fluoride in plaque fluid and saliva, but had no effect on plaque fluid pH. In vivo water rinsing, however, increased plaque fluid free calcium, apparently due to water-induced loss of calcium-binding ions. Water- or fluoride-rinse-induced changes in plaque fluid concentration were greater at the lower molar site, suggesting that rinse pooling may influence ion distribution. Before the water rinse, plaque fluid, saliva and whole-plaque total fluoride values were 1.7, 2 and 4 times higher after the CR rinse compared to the NaF rinse. Furthermore, the CR rinse deposited approximately 11 times more water-extracted fluoride compared to the NaF rinse, suggesting a 'more efficient' precipitation of 'labile' or 'loosely bound fluoride'. The results presented here, and in previous studies, suggest the possibility of formulating effective fluoride dentifrices with a lower fluoride content than is currently in use.

Purpose: To determine clinically the buccal absorption and plaque retention of triclosan from a mouthrinse containing 0.03% triclosan., Materials and Methods: 15 ml of the triclosan oral rinse (N=9) or placebo mouthrinse (N=12) was used twice daily for 21 days in humans. Blood, dental plaque and the expectorated oral rinse were collected prior to, during the treatment period at given intervals, and 8 days after the treatment. Dental plaque and blood samples were collected 1 hr and 4 hr after the morning rinse, respectively. The oral retention of triclosan was calculated by subtracting the amount of triclosan recovered in the expectorate from the triclosan dose applied (4.50 mg) in the mouthrinse. Plasma samples were analyzed for free triclosan (the parent molecule) and its glucuronide and sulfate conjugates, whereas dental plaque was analyzed only for total triclosan., Results: No significant treatment-related adverse effects were observed during the clinical phase of the study. The average daily oral retention of triclosan was calculated to be 0.660 mg, which is 7.33% of the triclosan dose applied (2 x 4.50 mg). Plaque contained an average 20.5-46.4 microg of triclosan per g of plaque collected. At various sampling times, mean plasma concentrations were: no detectable triclosan, 63.8-86.3 microg/ml of triclosan glucuronide and 8.23-18.0 ng/ml of triclosan sulfate. The mean total triclosan plasma concentration ranged from 74.5 to 94.2 microg/ml with plateau concentrations reached after 2 days of dosing. Eight days after the last treatment the triclosan plasma concentration returned to baseline levels (< 2 ng/ml).

Plaque fluid ion concentration changes, especially fluoride, in response to the pH decrease associated with a cariogenic episode are important components of the caries process. A "controlled-release" (CR) fluoride rinse, based on the controlled release of fluoride in the presence of calcium, has been shown to form large fluoride reservoirs in resting plaque. In this study, the in vitro acid-induced release of fluoride, and other ions, was examined in 48-hour-fasted plaque fluid from subjects (n = 11) who received no rinse, or who used a 228-ppm CR or NaF fluoride rinse 1 hr before being sampled. After collection, the plaque was centrifuged to yield plaque fluid, acidified (0.1 microL of 0.5 mol/L HCl per milligram plaque), and then re-centrifuged before a second sample was obtained. Although previous studies indicated a higher plaque fluid fluoride after the new rinse relative to NaF, no statistically significant difference was observed here. Average fluoride release after acidification (average pH, 5.2) was statistically greater following the use of the CR rinse (153 micromol/L) compared with the NaF rinse (17 micromol/L). No fluoride release was seen in the no-rinse samples. The pH, free calcium, phosphate, acetate, propionate, and buffer capacity were not affected by the different amounts of fluoride deposited in the plaque. However, following acid addition, an increase in free calcium and phosphate was observed, which was also independent of the rinse. The large release of fluoride following acidification suggests that the new rinse may provide an improved cariostatic effect.

Colostral products from non-immunized cows (CP) and cows immunized with mutans streptococci (IP) were used as mouth rinses in a short-term human study. The acidogenic potential of the products was tested and found to be negligible in vivo before application to subsequent rinsing tests. At first, all the participants received a professional tooth cleaning, after which they rinsed with one of the solutions (IP; CP; water) three times per day for 3 d. After each rinsing period, the resting pH and decrease in plaque pH after sucrose challenge were determined, the amount of plaque was estimated, and all available plaque was collected. No significant differences were recorded in the composition or in the amounts of accumulated plaque. The resting pH values of plaques with low "innate" pH were increased after the IP rinsing period. Surprisingly, the lowest pH values after the sucrose challenge were recorded in IP plaques. The number of cultivable facultative flora or total streptococci were not affected by different rinsings, but the relative number of mutans streptococci significantly decreased after the IP rinsing period when compared to the CP period. Thus, the short term rinsing indicates favourable effects of bovine immune whey on human dental plaque.

Most research on the chemical modification of dental plaque has used material from buccal and lingual smooth surfaces of teeth--plaque that is readily accessible to treatment solutions. The aim of this study was to test, on the more sheltered approximal plaque, the effect of a mouthrinse previously found to be effective in raising calcium, phosphate, and fluoride concentrations in accessible plaque. Five young adults participated in a blind, cross-over trial to compare a Ca-P-MFP-urea test rinse and a NaCl placebo rinse. For 6 days, subjects rinsed twice per day after their normal toothbrushing, using 10 ml of rinse solution for 30 seconds and a fresh 10 ml for a further 30 seconds. A non-fluoride toothpaste was used and normal flossing was withheld. Plaque was collected before rinsing and again 16 hours after the final rinse from all approximal sites except those between the lower anterior teeth. Pre- and post-rinse calcium values were 291 +/- 100 and 511 +/- 107 nmol/mg protein (mean +/- SD) respectively for the test rinse, and 368 +/- 223 and 306 +/- 125 nmol/mg protein respectively for the placebo. Analysis of variance showed that the test rinse had a significant effect on plaque calcium but not on phosphate or fluoride. Mean calcium values of about 2,400 nmol/mg protein have been obtained previously in smooth-surface plaque after use of the test rinse. The reduced effect here is probably due to restricted access of the rinse solution.

A micro-analytic method, capable of measuring the fluoride concentration in 5 nl of plaque fluid, was used to follow changes in fluoride concentration in saliva and plaque fluid at 6 single tooth-sites in 6 subjects for 180 min after a 0.048 M fluoride rinse as a NaF or MFP (sodium monofluorophosphate) solution. The maximum fluoride concentrations in saliva after NaF was 13x higher than with MFP. About 5% of the total amount of fluoride following the 20 ml NaF rinse was retained in the oral cavity. The corresponding figure followig MFP was <1%. The saliva/plaque fluid fluoride ratios for upper molars and lower incisors were significantly higher than for the upper incisors and lower molars. There was a tendency for a decline in the ratios with respect to time for all sites. To characterize the plaque fluid fluoride intra-oral single-site distribution and clearance, fluoride concentration versus time (AUC) was calculated from 10 to 60 min after a rinse. The NaF AUC followed the order: upper incisor, lower molar, upper molar and lower incisors reflecting a different exposure and clearance pattern due to the different access of the plaque to saliva. The MFP AUC values varied more, but were all significantly lower than the NaF AUC values. Analysis of plaque fluid fluoride curves at various sites revealed an exponential decline in most cases. With NaF, the baseline plaque fluid fluoride levels were not reached within 3 h. It is concluded that NaF solutions result in a significantly higher intra-oral fluoride exposure than MFP solutions. The fluoride distribution and clearance of fluoride from different sites in the oral cavity are linked to salivary access to these sites. These site-specific differences may have clinical consequences with regard to the dynamics of fluoride in the de- and remineralization processes.

Recent studies showed that salivary, plaque-fluid, and whole-plaque fluoride were significantly higher 120 min after subjects rinsed with a novel two-solution rinse than after they rinsed with a NaF rinse of the same fluoride concentration. In this study, the persistence of these increases was investigated overnight, a period of time that is more clinically relevant. Improved analytical techniques for the ultramicro determination of whole-plaque and plaque-fluid fluoride from the same sample are also described. Thirteen subjects abstained from toothbrushing for 48 hrs and rinsed for 1 min with a 12 mmol/L (228 ppm) NaF or the two-solution rinse before bedtime. Samples were then collected the following morning before breakfast: (1) Saliva samples were either clarified by centrifugation or acid-extracted with 1 mol/L HClO4; and (2) single-site molar plaque samples were centrifuged to obtain plaque fluid and/or extracted with 1 mol/L HClO4. Results showed that, compared with NaF, the two-solution rinse produced significantly higher fluoride concentrations in all samples: The concentration of fluoride in whole plaque and whole saliva following the new rinse exceeded concentrations found after the NaF rinse by factors of three and four, respectively, while in plaque fluid, the two-solution rinse produced about a two-fold increase over NaF values, which were near baseline levels. This increase, however, was only about 20% in centrifuged saliva. The increases in saliva and especially in plaque-fluid fluoride after the two-solution rinse indicate a greater remineralization potential, while the enhanced fluoride reservoirs found in plaque overnight after this rinse constitute a reserve that may release fluoride into the plaque fluid over an extended period of time.

The main objective of this study was to evaluate the effects of a single use of a mineralizing mouthrinse on dental plaque pH and on its mineral contents: an additional objective was to examine the effects of an oral prophylaxis and scaling on the same response variables. A total of 22 volunteer dental students (14 female and 8 male) participated in the study. The mineralizing mouthrinse contained calcium, phosphate, strontium and fluoride ions. Following a 48-hour period without oral hygiene and 2 hours after breakfast, dental plaque was collected twice from each participant for the evaluation of the effects of the oral prophylaxis and scaling, and twice more for the evaluation of the effects of the mineralizing mouthrinse. The pH was measured in vitro with a microelectrode and the mineral contents were determined by atomic emission spectrometry. The results demonstrate that the average post-prophylaxis pH was higher than the average pre-prophylaxis pH, and that a variation of the average contents of some minerals in the dental plaque was also observed after prophylaxis compared to the contents prior to prophylaxis. Although there was a significant reduction in the Fe content after the rinse with the mineralizing solution, no significant variation on the average pH was detected.

This study describes an in vivo inhibition of dental plaque growth after peroxidase-generated hypoiodite (OI-) mouth-washes. After giving up all other usual hygiene procedures nine healthy volunteers washed their mouth using 10 ml of the mouth-wash [H2O2 (0.005%), KI (50 mM) and lactoperoxidase (0.04%)] three times a day for 1 minute for 3 days. The initial oxidation power of this mixture represented 430 +/- 11 microM oxidised cysteine (n = 6), dropping down to 87 +/- 6 microM after the solution was spat out (n = 5). A saline solution served as a negative control, and a 0.2% chlorhexidine digluconate solution as a positive control. Proximal dental plaque between mandibular canine and lateral incisor (left and right) was collected after 3 days using standardized sterile toothpicks, then analysed for ATP and protein content. ATP concentrations dropped to 49% of the control values after OI- rinsing, and to 9% after chlorhexidine rinsing while the protein content dropped to 48% for OI- versus 31% for chlorhexidine. However, when considering the ATP content per protein micrograms, only the decrease to 6% of the initial value in the chlorhexidine testing was significant while the drop to 81% for the OI- testings was not significant. This study points out a negative effect of OI- on plaque growth in vivo.

The aim of the present investigation was to study two post-brushing water rinsing procedures: (1) on fluoride (F) accumulation in approximal dental plaque, and (2) on F clearance in the interdental area. Twenty subjects participated first in the accumulation study, including three experimental periods (A, B and C), each lasting for 7 days. During period A, they brushed with a 0.32% NaF dentifrice for 2 min, followed by a 1-min active mouth rinse with the toothpaste foam combined with 5 ml of water. During period B, the 2-min brushing was followed by three quick water rinses with 15 ml each. During period C, toothbrushing, which was carried out without any toothpaste, was followed by a 2-min active mouthrinse with 10 ml of a 0.05% NaF solution. All three procedures were performed in the morning (after breakfast) and in the evening (just before bedtime). The results showed that the accumulation of F in pooled approximal plaque after 7 days reached on average 2.7 times higher values after procedure A than B (p<0.001). Procedure C also resulted in more F in plaque than B (p<0.001). The same 20 subjects participated in the clearance study on a separate occasion. When measuring the F concentration in the interdental area at 3 h after the application, procedure A resulted in a significantly higher F concentration than both toothbrushing B and mouth rinse C; the AUC was 2.2 times larger for A than for B (p <0.001). Thus, both the accumulation of F in approximal plaque and the clearance of F in the interdental area are related to the mode of water rinsing after toothbrushing.

Inhibition of dental plaque acidogenicity by chlorhexidine (CHX) mouthrinses has been ascribed to a long-lasting bacteriostatic effect due to binding of CHX to oral surface structures combined with a slow release rate from the binding sites. The present aims were to study the effects of CHX-containing mouthrinses on the viability and glycolytic activity of established plaque in order to assess the bactericidal versus the bacteriostatic effects. Following 2 days of plaque accumulation, three groups of 10 students rinsed with either 12.0 mM NaF, 0.55 mM CHX plus NaF, or with 2.2 mM CHX plus NaF. Plaque samples were collected before and 90 min after mouthrinsing. The pH in pooled pre- and post-rinse plaque samples was recorded before and up to 10 min after the addition of D-[U-14C]glucose. Total colony-forming units in each sample were determined. High-performance liquid chromatography analyses showed lactate to be the major extracellular glycolytic metabolite in all samples. CHX-NaF markedly reduced the colony-forming units, the pH fall from fermentation of glucose, as well as glucose consumption and lactate formation, whereas NaF alone exhibited no such effects. The reduction of glucose consumption by the CHX-NaF mouthrinses corresponded to the reduction of colony-forming units, indicating no bacteriostatic effect. The plaque pH in vivo was monitored in each student 90 min after mouthrinsing with the test solutions prior to and up to 1 h after a sucrose mouthrinse using touch microelectrodes. The CHX-NaF mouthrinses reduced the fall in pH significantly (p < 0.05) as compared with the NaF mouthrinse.(ABSTRACT TRUNCATED AT 250 WORDS)

The concentrations of fluoride in various samples from the oral environment were measured at timed intervals after a novel rinse or a NaF rinse, both containing a total of 12 mmol/L (228 ppm) fluoride. The novel rinse consisted of two solutions mixed just before application: Part A contained calcium chloride and sodium acetate; part B contained a hydrolyzable source of fluoride (sodium hexafluorosilicate) and sodium phosphate. Samples were obtained as follows: Single-site plaque-fluid samples were obtained by centrifugation of first-molar plaque; pooled whole-plaque samples were collected from second molars; centrifuged, pooled whole-saliva was collected by vacuum. All samples were analyzed by micro-analytical methods. Results showed that, compared with NaF, the two-solution rinse produced significantly higher salivary fluoride concentrations, plaque-fluid fluoride concentrations, and acid-extractable fluoride in the whole plaque by factors of about 4, 2, and 6, respectively, at 120 min. The results of this study suggest that the new rinse may provide a greater cariostatic effect at the same fluoride dosage than does a NaF rinse.

The zinc content in dental plaque after mouth rinsing with 0.2% zinc chloride solution is dependent on previous mouth rinsing with different pH value. Zinc retention is strongly reduced by rinsing with citric acid solution (pH value 1.0). Zinc retention is growing with increasing pH value when rinsing was made with sodium citrate buffer solution with increasing pH value. A rinsing with sodium citrate buffer solution (pH value 6.3) following a 0.2% zinc chloride solution leads to a drastic reduction of the zinc content. However, a chlorhexidine solution with the same pH value leaves no washing out effect.

The aim of the study was to assess the effect of an amine fluoride/stannous fluoride toothpaste and mouthwash on dental plaque and gingivitis, plaque F- accumulation, F- content and acid solubility of dental enamel. Participants in the 12-week double-blind study were 92 schoolchildren, with a mean age of 12.4 years, randomly distributed to four groups: (1) AmF/SnF2 toothpaste, (2) placebo toothpaste, (3) AmF/SnF2 toothpaste plus AmF/SnF2 mouthwash, (4) placebo toothpaste plus AmF/SnF2 mouthwash. Analyzing the results, the mean values of dental plaque (Silness-Löe index) and of the sulcus bleeding index decreased statistically significantly in all groups except the placebo toothpaste users. Plaque F- and enamel F- content increased considerably only in the two groups using the AmF/SnF2 toothpaste. A decrease in acid solubility was significant only in the group of both test toothpaste and test mouthwash users. Thus the clinical efficacy of the tested AmF/SnF2 toothpaste might be increased by the combined use of mouthrinsings containing the same substances.

A transistor pH electrode (pH-ISFET electrode) was placed in each of four human mouths and bacteria were allowed to accumulate on it for 1, 2 or 3 days. Changes of plaque pH were measured in situ after application of sucrose solution (0.1, 1 or 3%) and, then, quick pH recovery by mouth-rinses with water was estimated. Although the acidic pH after application of 0.1% sucrose was easily and quickly recovered from by a few mouth-rinses with water, rather frequent mouth-rinses with water were required to recover from the acidic pH of 2- or 3-day-old plaque after the application of a 1 or 3% sucrose solution. For example, 15 (mean, n = 4) mouth-rinses with water were required for the 3 day-old plaque pH to recover after the application of 3% sucrose solution.