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In a randomized clinical trial, we evaluated the effect of a 10% chlorhexidine varnish (Chlorzoin) on the mother-child transmission of Streptococcus mutans and on subsequent caries experience. Chlorhexidine (n = 38) or a placebo varnish (n = 37) was applied to the dentitions of 75 mothers at a time when their first babies were about 6 months old (approximate time of first tooth emergence). Three more applications at weekly intervals and subsequent applications at 6-month intervals followed the initial application. The mother-child pairs were followed up until the child's fourth birthday. Maternal salivary S. mutans levels in the treatment group remained significantly lower (p < 0.05) compared to the control group up to 12 months after the initial application. However, this intervention did not significantly alter the S. mutans colonization in children or the caries increment in either the mother or the child., (Copyright 2002 S. Karger AG, Basel)

Since researchers first became aware of the anticaries action of fluoride, they have been investigating the effect of this preventive agent in inhibiting or arresting caries development. Many forms of systemic or topical fluoride have been studied and tested for clinical application. Water, salt, milk fluoridation and the use of fluoride supplements were introduced for systemic fluoridation mainly using sodium fluoride. Solutions, gels, toothpastes and rinses of sodium fluoride, stannous fluoride, amine fluorides, acidulated phosphate fluoride and monofluorophosphate were used for topical fluoridation. More recently nonaqueous fluoride varnishes in an alcoholic solution of natural resins and difluorosilane agents in a polyurethane matrix were introduced. Although all of these fluoridation methods have a caries-preventive action, these benefits and the ease of application is variable. As fluoride is a key component of oral health promotion a coordinated approach on a community and individual basis seems to be needed to maximize the cost-benefit ratio of prevention., (Copyright 2001 S. Karger AG, Basel.)

Toothbrushing with fluoride dentifrice has become an important public health measure in preventing caries and gingivitis. Since the fluoride concentration in dentifrices does not provide absolute protection for everyone and is limited by legal regulations, the question about the efficacy of additional use of topical fluoride products arises. In children aged 9-15 years, the biannual application of Duraphat varnish in school-based programmes provides a caries inhibition of 38%. A caries inhibition of up to 40% can also be achieved by gels containing 1.25% fluoride, if applied 30 times per year. In subjects with a risk of root caries, the daily use of a 250-500 ppm fluoride solution seems to be advisable., (Copyright 2001 S. Karger AG, Basel.)

From 1990 onward the decline of caries has leveled off in economically developed countries and the effectiveness of preventive programs seems to have diminished. The aim of this paper is to consider the future of caries prevention in the light of the studies conducted during the past decade. A shift from population-based prevention to a high-risk strategy has been promoted in countries where caries is strongly polarized. In Finland, however, an intensive preventive program targeted to high-risk individuals had little effect on caries increment, which suggests that the utility of a high-risk strategy is questionable. The relative effects of population-based methods have also decreased during the last decades. Although discontinuation of water fluoridation had no effect on caries in Kuopio, Finland, water fluoridation is still effective in countries with a lower level of basic prevention and a less homogenous social structure. From the standpoint of cost-effectiveness, the use of professionally applied fluoride gels has been questioned in children with a low caries rate, and the same is probably true for fluoride varnishes. In countries with a high caries rate, a low level of basic prevention, and an unorganized dental care system any preventive program seems to be effective. The importance of fluoride toothpastes as a cost-effective and feasible method of fluoride delivery is indisputable and will be so in all countries irrespective of the caries level and dental care systems. Population-based dental health education continues to be important, also in the countries where the caries rate has so far been low., (Copyright 2001 S. Karger AG, Basel.)

A professionally applied two-stage chlorhexidine varnish, Chlorzoin((R)), was developed to achieve sustained release and minimise the problems of staining and bad taste associated with chlorhexidine mouthrinses. The primary aim of this randomised controlled clinical trial was to assess the efficacy of Chlorzoin in reducing the caries increment in high-caries-risk adolescents. Secondary aims included investigating the effect of compliance upon caries increment, the effect of Chlorzoin upon salivary mutans streptococci levels and assessing the benefit of individual dental health advice by dental auxiliaries in a community setting. 1,240 children, initially aged 11-13 years, assessed to be at high caries risk were recruited into the trial. The trial design involved four arms: an observational group, a control group, an active (Chlorzoin) varnish group and a placebo varnish group. All subjects were examined annually by a calibrated examiner who was blind to the group allocation. Three-year caries increments were calculated using clinical, clinical and fibre-optic transillumination, and clinical and bitewing data sets. The results indicated that the use of Chlorzoin had an initial effect on mutans streptococci levels but that no long-term reduction in caries increment or mutans streptococci infection could be detected. One reason for this lack of efficacy may have been the regimen of reduced frequency of varnish applications after the initial period. Children who followed the protocol and, therefore, were seen regularly by dental auxiliaries had a lower caries increment than those who did not. This finding was independent of varnish allocation. In summary, under this regimen, Chlorzoin has been found to be effective in decreasing salivary mutans streptococci but ineffective as a caries-preventive agent in high-risk Scottish children when applied pragmatically in a community setting.

Clinical studies suggest that application of a highly concentrated chlorhexidine varnish results in a decrease in the number of mutans streptococci and thereby a decrease in the caries risks. The aim of this study was to determine the effect of dental treatment on the levels of mutans streptococci (MS) and lactobacilli (LB) and the additional effect of a single application of 40% chlorhexidine varnish (EC40) on the level of MS. Twenty-three children under the age of 5 years scheduled for full dental treatment were selected. Of these 23 children (mean dmf-s 27.1, SD 19.3), 11 children had nursing bottle caries. The mean sugar exposure was 6.4. Subjects were randomly distributed into two groups of approximately equal size. One group received an EC40 application after dental treatment, while the other group received only full dental treatment, both with intravenous anaesthesia with propofol as a single drug. An unstimulated saliva sample and a plaque sample were taken prior to dental treatment. The saliva and plaque sampling of the subjects was repeated after 6 weeks. MS and LB were isolated and counted. The number of children harbouring more than 10(6) MS in a pooled plaque sample decreased significantly from 8 to 2 children 6 weeks after dental treatment. No additional effect of EC40 was found. The number of salivary MS did not change significantly between the groups or before and after treatment. The figures for LB remained at a high level of more than 10(4)/ml saliva before (21 children) and 6 weeks after treatment (17 children). The results of this study indicate that dental treatment results in a significant suppression of plaque MS, while a single application of EC40 showed no significant additional suppression after 6 weeks.

The aim of this study was to evaluate the effect of four different dental varnishes on the colonization of mutans streptococci, total streptococci and lactobacilli on exposed sound root surfaces. Sixty-five individuals were randomly allotted to one of four groups for treatment with Cervitec((R) ) varnish containing 1% chlorhexidine and 1% thymol, a thymol varnish or one of two different fluoride varnishes, Fluor Protector and Duraphat. The varnish was applied to three buccal root surfaces in each patient at baseline and after 1 week. Dental plaque from the root surfaces was collected and analysed on four different occasions: at baseline, after 1 week, 1 month and 6 months. The Cervitec varnish caused a statistically significant reduction in the number of mutans streptococci over time. The reduction was significant at 1 week and 1 month relative to baseline. The numbers of total streptococci and lactobacilli were not significantly affected by treatment with Cervitec. No statistically significant difference over time was found for mutans streptococci, lactobacilli or total streptococci after treatment with the fluoride varnishes or the thymol varnish.

The aim of the present study was to evaluate and compare the effects of three different chlorhexidine (CHX)-containing preparations on mutans streptococci (MS) levels in interdental plaque and whole saliva. Ninety-three healthy school-children (8-10 years old) with high scores of salivary MS were selected by a screening procedure and randomised into three equally sized groups. MS were enumerated at all mesial interdental sites of the first permanent molars with aid of a modified chairside technique. The patients were then treated three times within 2 weeks with either a 1% CHX/thymol-containing varnish (group A) or a 1% CHX gel (group B), or they were subjected to daily supervised toothbrushing with a 0.4% CHX dentifrice for 1 month (group C). Follow-up samples of saliva and plaque from the interdental sites were collected 1 and 3 months after termination of treatment. A statistically significant reduction of MS levels in saliva and interdental plaque was found in all groups after 1 month. The CHX-containing dentifrice (group C) was the most effective method in reducing MS levels in saliva, and a significantly stronger (p < 0.05) suppression was found after 1 and 3 months when compared with the gel and the varnish forms. The gel (group B) tended to be slightly more effective than the varnish (group A). In the interdental plaque, the reduction of MS was less marked than in the saliva, and the three groups exhibited MS reductions of similar magnitude (20%) and duration, persisting up to 3 months. However, a high proportion (approximately 50%) of all interdental sites were relatively unaffected by the treatments. In conclusion, our results suggest that the interdental MS colonisation was difficult to combat, irrespective of CHX preparation and method, while the salivary levels were more easily affected. Daily tooth-brushing with a CHX-containing dentifrice was more effective in reducing MS in saliva compared with the gel or varnish applications.

The effect of an antibacterial varnish (Cervitec) on the levels of mutans streptococci in plaque adjacent to bonded orthodontic brackets was evaluated in 18 children using a split-mouth technique with a placebo varnish control. The test varnish contained 1% chlorhexidine and 1% thymol as active ingredients. Both varnishes were applied on four occasions during a 3-month period, and plaque was subsequently collected between 1 week and 6 months after the onset of treatment. All teeth involved in the study were carefully examined and clinically assessed for enamel demineralization prior to onset of the fixed appliances and immediately after debonding. The results showed a more frequent growth of mutans streptococci in the dental plaque collected from placebo-treated quadrants as compared with the test quadrants on all sampling occasions. The proportion of mutans streptococci within the plaque microflora was significantly (p < 0.05-0.01) lower on the test sides than on the opposite sides at the 1-week and 1-month examinations. The incidence of incipient enamel lesions around the brackets and along the gingival margin was generally low, and no differences were found between the test and placebo varnish treated quandrants at the time of debonding. The results suggest that mutans streptococci in plaque from orthodontic patients can be suppressed effectively by topical applications of an antibacterial varnish.

The effect on local plaque formation of a varnish containing 1% chlorhexidine and 1% thymol (Cervitec) was evaluated. Ten volunteers with clinically healthy oral conditions were asked to refrain from any kind of oral hygiene measures for three periods of three days. Undisturbed plaque formation was recorded during the first experimental period. At the beginning of the second period, the varnish was applied to six vestibular enamel surfaces and removed after 1 h. The third experimental period was initiated 12 weeks after varnish application to assess a potential long-term effect. During each period of plaque formation, samples were collected from the vestibular surfaces after 24 h (from teeth 15/25), after 48 h (from teeth 14/24) and after 72 h (from teeth 13/23), respectively, and evaluated for total microscopic bacterial counts (BC) and colony forming units (CFU). Microbial vitality was assessed by the plating efficiency [PE = (CFU/BC) x 100] and directly by a vital fluorescence (VF) technique. VF of 48- and 72-hour plaque was significantly reduced after Cervitec application. An inhibitory effect by Cervitec could not be discerned 12 weeks after varnish treatment.

The aim of this study was to determine the effects of one and two applications of 40% chlorhexidine varnish on the numbers of mutants streptococci in human dental fissure plaques from molar and premolar teeth. Twenty-nine subjects (aged 20-30 years) participated in the study and were randomly assigned to one of three groups. In each subject two fissures with high levels of mutants streptococci were selected. The fissures in group 1 (control group) were treated with placebo varnish containing no chlorhexidine. Fissures in group 2 received a single application of 40% chlorhexidine varnish, whereas fissures in group 3 received an additional chlorhexidine varnish application 1 week after the first application. Fissure plaque samples were taken prior to the first application of chlorhexidine varnish and subsequently 1, 2, and 4 months thereafter. Compared with the fissures in the control group, the suppression of mutans streptococci was significant in plaques from group 2 for up to 2 months and in plaques from group 3 for up to 4 months after application. Mutans streptococci were suppressed more strongly in premolar than in molar teeth and more strongly and for a longer period of time in fissures of premolar teeth treated twice than in fissures of premolars treated once.

The cariostatic efficacy of rinsing with a 0.05-0.2% neutral sodium fluoride solution has been clearly demonstrated, especially in supervised school-based programmes in moderate and high caries risk children. The cost-benefit effect, however, is questionable in populations with low caries prevalence, and fluoride rinsing programmes are gradually being replaced by more individual fluoride therapy comprising combinations of fluoride toothpastes, tablets, or varnishes. Fluoride varnishes were developed as individual alternatives to conventional topical fluoride application and are today gaining acceptance for clinical application. Two varnishes, Duraphat containing 5% wt NaF and Fluor Protector with 0.9% wt fluor silane, are available commercially. The clinical effects seem to depend mainly on application frequency, especially in high caries risk groups. The cost-benefit effect is high, but can be increased by delegating application to auxiliary personnel in conjunction with regular dental visits. Toxicologically both fluoride mouthrinses and fluoride varnishes are safe if used as directed.