Clinical trial in adults of an antimicrobial varnish for reducing mutans streptococci

Caries lesion remineralization with fluoride toothpastes and chlorhexidine - effects of application timing and toothpaste surfactant

Habitual toothbrushing with fluoridated toothpaste followed by rinsing with antibacterial mouthwashes is a method to maintain good oral hygiene and to diminish the occurrence and severity of dental caries and periodontal disease. However, our understanding of how antimicrobial agents in mouthwashes affect fluoride-mediated caries lesion remineralization is still poor.

Comparison of the Effect of Fluoride Varnish, Chlorhexidine Varnish and Casein Phosphopeptide- Amorphous Calcium Phosphate (CPP-ACP) Varnish on Salivary Streptococcus mutans Level: A Six Month Clinical Study

INTRODUCTION

Dental caries is the most widespread disease which has a multi factorial origin. Streptococcus mutans is considered to be the chief pathogen in its development. Different varnishes are available which can be used for the prevention of the carious process.

AIM

To compare the effect of fluoride varnish, chlorhexidine varnish and fluoride varnish containing Casein Phosphopeptide - Amorphous Calcium Phosphate (CPP-ACP) on salivary Streptococcusmutans count in children with mixed dentition over a period of six months.

MATERIALS AND METHODS

Seventy two children of age 6-12 years with mixed dentition were selected fulfilling inclusion and exclusion criteria and divided into three groups: Group I- Fluoride varnish group; Group II- Chlorhexidine varnish group; Group III- MI varnish (fluoride varnish containing CPP-ACP) group. After thorough oral prophylaxis and restorative treatment the varnishes were applied to the teeth once a week for four consecutive weeks in the respective groups. Salivary Streptococcus mutans count (CFU/ml of saliva) was estimated at baseline, 1 month, 3 months and 6 months after varnish application. Bonferroni post-hoc test and paired t-test for inter group and intra group comparison was used in the study.

RESULTS

A statistically significant reduction in salivary S. mutans colony count was seen with all three groups at all the different time intervals. Maximum reduction was noted in chlorhexidine varnish group at all the intervals after varnish application.

CONCLUSION

Prevention of dental caries plays a vital role in paediatric dental practice. The use of dental varnish has proved to be effective in reducing the dental caries. Chlorhexidine varnish was found to show maximum reduction in salivary S. mutans count for six month period, when compared to MI varnish and fluoride varnish. Thus, chlorhexidine varnish can be used as potent caries inhibiting agent and promote good oral health.

Sustained-release drug delivery of antimicrobials in controlling of supragingival oral biofilms

INTRODUCTION

Dental caries, a bacterial biofilm-associated disease, is a prevalent oral health problem. It is a bacterial biofilm-associated disease. Conventional means of combating this disease involves oral hygiene, mostly tooth brushing. Supplementary means of prevention and treatment is often necessary. The use of sustained-release delivery systems, locally applied to the oral cavity appears to be one of the most acceptable avenues for the delivery of antimicrobial agents. Area covered: The development and current approaches of local sustained delivery technologies applied to the oral cavity for treatment and prevention of dental caries is discussed. The use of polymeric drug delivery systems, varnishes, liposomes and nanoparticles is presented. Expert opinion: The use of local sustained-release delivery systems applied to the oral cavity has numerous clinical, pharmacological and toxicological advantages over conventional means. Various sustained-release technologies have been suggested over the course of several years. The current research on oral diseases concentrates predominantly on improving the drug delivery. With progress in pharmaceutical technology, sophisticated controlled-release platforms are being developed. The sustained release concept is innovative and there are few products available for the benefit of all populations. Harmonizing academic research with the dental industry will surely expedite the development and commercialization of more products of such pharmacological nature.

Efficacy of a 10% chlorhexidine coating to prevent caries in at-risk community-dwelling adults

OBJECTIVE

The purpose of the study was to determine the efficacy of a 10% chlorhexidine tooth coating in reducing the incidence of cavitated carious lesions in adults.

MATERIALS AND METHODS

The trial was a randomized, double-blind, multi-center, placebo controlled study with 983 participants, receiving the application of either the active or the placebo coatings to the entire dentition. Four applications were made in the first month and one at the 7th month. The final examination was performed at 13 months.

RESULTS

Coronal caries showed a statistical reduction (p = 0.02). Examination of the results by site showed that the highest risk participants experienced the most significant preventive effect (p = 0.003). When two sites (uninsured and public health) are pooled the treatment p-value is 0.0009, interaction term has a p-value of 0.0001.

CONCLUSION

10% Chlorhexidine was highly effective in high risk participants with more than two cavities at the initial examination. This trial in conjunction with other published trials of this topical medication indicates that chlorhexidine exerts its action by preventing the transition of D1 lesions to cavitated lesions, not on sound to D1 lesions.

Effects of typified propolis on mutans streptococci and lactobacilli: a randomized clinical trial

OBJECTIVE

The aim of this study was to determine in a randomized, double-blind, placebo-controlled clinical trial the effects of typified propolis and chlorhexidine rinses on salivary levels of mutans streptococci (MS) and lactobacilli (LACT).

METHODS

One hundred patients were screened for salivary levels of MS >100,000 CFUs/mL of saliva. All patients presented with at least one cavitated decayed surface. Sixty patients met entry criteria. Subjects were adults 18-55 years old. After restoration of cavitated lesions patients were randomized to 3 experimental groups: 1) PROP-alcohol-free 2% typified propolis rinse (n = 20); 2) CHX- 0.12% chlorhexidine rinse; 3) PL-placebo mouthrinse. Patients rinsed unsupervised 15 mL of respective rinses twice a day for 1 min for 28 days. Patients were assessed for the salivary levels of MS (Dentocult SM) and LACT (Dentocult LB) at baseline, 7-day, 14-day, and at 28-day visits (experimental effects) and at 45-day visit (residual effects). General linear models were employed to analyze the data.

RESULTS

PROP was superior to CHX at 14-day and 28-day visits in suppressing the salivary levels of MS (p < .05). PROP was superior to PL at all visits (p < .01). The residual effects of PROP in suppressing the salivary levels of MS could still be observed at the 45-day visit, where significant differences between PROP and CHX (p < .05), were demonstrated. PROP was significantly superior than CHX in suppressing the levels of salivary LACT at the 28-day visit (p < .05).

CONCLUSION

Typified propolis rinse was effective in suppressing cariogenic infections in caries-active patients when compared to existing and placebo therapies.

Comparative evaluation of chlorhexidine varnish and fluoride varnish on plaque Streptococcus mutans count--an in vivo study

AIM

The aim of the study was to assess and compare the effect of chlorhexidine varnish and fluoride varnish application on Streptococcus mutans counts in plaque of occlusal pits and fissures of permanent mandibular first molars.

MATERIALS AND METHODS

The study was an in vivo comparative study, conducted among 50 schoolchildren aged 7-8 years under a field setting. The 50 subjects were randomly allocated into two groups. Baseline plaque samples were collected from all the subjects followed by the application of two varnishes, Cervitec and Duraphat. The varnish was applied to pit and fissures of occlusal surface of mandibular first molar. The varnish application was carried out on the first day, fifth day and tenth day after baseline plaque sampling. Subsequent plaque samples were collected at the end of 1 month and at the end of 3 months after the varnish application.

RESULTS

The Cervitec varnish has shown a statistically significant reduction at the end of 1 month and at the end of 3 months (P < 0.05). Duraphat varnish did not show a statistically significant difference in reducing the plaque S. mutans count at the end of 1 month and third month (P > 0.05).

CONCLUSION

Cervitec varnish was found to be effective in reducing S. mutans count for a 3-month period, when compared to Duraphat varnish.

A randomised, controlled clinical trial comparing chlorhexidine gel and low-dose fluoride toothpaste to prevent early childhood caries

OBJECTIVES.  This randomised, controlled trial compared the effectiveness of 0.12% chlorhexidine (CHX) gel and 304% fluoride toothpaste to prevent early childhood caries (ECC) in a birth cohort by 24 months. METHODS.  The participants were randomised to receive either (i) twice daily toothbrushing with toothpaste and once daily 0.12% CHX gel (n = 110) or (ii) twice daily toothbrushing with toothpaste only (study controls) (n = 89). The primary outcome measured was caries incidence and the secondary outcome was percentage of children with mutans streptococci (MS). All mothers were contacted by telephone at 6, 12, and 18 months. At 24 months, all children were examined at a community dental clinic. RESULTS.  At 24 months, the caries prevalence was 5% (3/61) in the CHX and 7% (4/58) in the controls (P = 0.7). There were no differences in percentages of MS-positive children between the CHX and control groups (54%vs 53%). Only 20% applied the CHX gel once daily and 80% less than once daily. CONCLUSIONS.  Toothbrushing using 304% fluoride toothpaste with or without the application of chlorhexidine gel (0.12%) reduces ECC from 23% found in the general community to 5-7%. The lack of effect with chlorhexidine is likely to be due to low compliance.

Emerging technologies for the prevention of dental caries. Are current methods of prevention sufficient for the high risk patient?

Fluorides and chlorhexidine are technologies that are 65 and 40 years old, respectively. This overview argues that current methods of caries prevention are not effective for the high caries risk patient. In this review examples, arguments and recommendations are provided to address the high caries risk patient that include: failure of comprehensive chemical modalities treatments to address the high caries risk patient; ecological alteration - would this be an effective approach?; and biomaterials and oral microbiome research to address the high caries risk patient.

Effects of Different Chlorhexidine Formulations on Shear Bond Strengths of Orthodontic Brackets

Objective: To test the hypothesis that the application of different chlorhexidine formulations to the etched enamel will not affect shear bond strength (SBS).

Materials and Methods: Forty-four freshly extracted human premolars were collected and stored in distilled water. The teeth were etched with 37% phosphoric and were rinsed and dried. The teeth then were divided into four equal groups. While Group 1 served as a control, Groups 2 to 4 were treated before bonding with a chlorhexidine formulation that included solution (2%), gel (1%), and mouthwash (0.2%). Orthodontic brackets were bonded with Transbond XT (3M Unitek, Monrovia, Calif). Bond strength results were evaluated with the use of one-way analysis of variance (ANOVA) (P &lt; .05) and post hoc tests. Modes of failures were verified by means of scanning electron microscopy.

Results: Although no statistically significant difference was observed between Groups 1 and 4 (P &gt; .05), both were statistically superior to Groups 2 and 3 (P &lt; .05). In this in vitro study, the observed measures for Groups 2 and 3 (14.5–10.6 MPa) were lower than those for Groups 1 and 4 (27.3–24.9 MPa), but these values were much higher than those required for clinical use (6–8 MPa).

Conclusion: The hypothesis is rejected. The application of chlorhexidine mouth rinse before bonding had no significant effect on the SBS value, and the application of chlorhexidine solution and gel significantly decreased SBS.

The Role of Chlorhexidine in Caries Prevention

Chlorhexidine rinses should not be recommended for use in caries prevention due to the current lack of evidence for their effectiveness.

Microbiota of Exposed Root Surfaces After Fluoride, Chlorhexidine, and Periodontal Maintenance Therapy: A 3-Year Evaluation

BACKGROUND

Fluoride and chlorhexidine (CHX) are state-of-the-art preventive measures for remineralizing teeth and for preventing plaque accumulation. The aim of this study was to examine the effects of fluoride and CHX varnishes on root caries and microbiota located on root surfaces.

METHODS

Thirty-three patients from a periodontal maintenance program, having at least one tooth with gingival recession in each quadrant, participated in this study. One tooth per quadrant was assigned randomly to the control group or to one of the test groups that were treated with fluoride varnish, 1% CHX, or 40% CHX. The varnish treatment and the tooth cleaning were repeated every 3 months. Clinical examinations were performed at baseline and once a year for 3 years. Caries status and oral hygiene indices were evaluated clinically. The total cultivable microbiota and percentage of Mutans streptococci (MS), Actinomyces (ACC), and lactobacilli (LB) were analyzed.

RESULTS

Oral hygiene was improved greatly during the course of the study. The percentage of MS, ACC, and LB of the total cultivable microbiota revealed a statistically significant reduction between baseline and final examination for each of the four groups.

CONCLUSION

Professional tooth cleaning alone at 3-month intervals might be as effective in reducing MS, ACC, and LB as adjunctive treatment with fluoride or chlorhexidine.

Photocatalytic antibacterial effect of TiO2 film formed on Ti and TiAg exposed toLactobacillus acidophilus

When irradiated under near-ultraviolet (UV) light, TiO(2) exhibits strong bactericidal activity. The TiO(2) photocatalyst would be effective on orthodontic appliances after its antibacterial effect on the carcinogenic microorganism Lactobacillus acidophilus is evaluated. To compare the antibacterial effect of two crystalline forms of TiO(2), rutile and anatase, thermal oxidation and anodic oxidation were employed to form each structure, respectively. The antibacterial effect of TiO(2) film on TiAg was also compared with that on Ti. Bacterial solutions were pipetted onto the TiO(2)-coated specimen and illuminated with UVA (2 x 15 W, black light, 356 nm) up to 100 min and the reaction solutions were incubated to count the colony-forming units. The antibacterial activity of the coated specimens was similar to that of the uncoated group. The antibacterial activity of the coated specimens of TiAg was not different from that of Ti. TiO(2) coatings formed on both Ti and TiAg specimens did not exhibit cytotoxicity on the L-929 cells of mice.

Antimicrobial Effectiveness of a Highly Concentrated Chlorhexidine Varnish Treatment in Teenagers with Fixed Orthodontic Appliances

Objective: To evaluate the recolonization pattern of Mutans streptococci (ms) on densely colonized teeth with fixed orthodontic appliances after treatment with a highly concentrated (36%) chlorhexidine varnish.

Materials and Methods: Healthy subjects (n = 19) with fixed orthodontic appliances and high bacterial ms counts in saliva were recruited. In order to establish a baseline registration, plaque adjacent to brackets was sampled and cultivated on Dentocult® strips. Following professional tooth cleaning, chlorhexidine varnish was applied on all teeth for 8 minutes. The degree of recolonization with ms was assessed 2 weeks after varnish application in plaque around the brackets. For statistical analysis, the data were subjected to a repeated measures design.

Results: After 2 weeks, ms counts were reduced as compared to baseline values. However, the reduction only weakly met statistical significance (P = .049).

Conclusions: The application of a highly concentrated chlorhexidine varnish in patients with fixed orthodontic appliances does not result in a distinct reduction of ms numbers 2 weeks after treatment.

Effect of an intensified treatment with 40% chlorhexidine varnish on plaque acidogenicity

Previous work showed that a single application of 40% chlorhexidine varnish, EC40, reduced plaque acidogenicity upon sucrose challenge during less than 3 weeks. It was questioned whether lactic acid production could be reduced significantly longer when the treatment was intensified. Therefore, the effects of three consecutive EC40 applications on plaque acidogenicity were evaluated. Nine subjects who participated in the previous study received three full mouth EC40 applications within 1 week. Before the first application and up to 9 weeks after the third application, plaque samples were taken after a 10% sucrose rinse and analyzed for organic acids with capillary electrophoresis. At baseline, the mean provoked lactic acid concentration was 1.64 (+/-0.69) micromol/mg protein. At the first and seventh day after the third application, there was too little plaque to measure acid concentrations. At 2 weeks after the third application, lactic acid concentrations were significantly reduced (p < 0.05). The acid concentrations 3 weeks after the third application (1.61 (+/-0.99) micromol/mg protein) did not differ from the values at baseline (paired T test, p > 0.05). We conclude that a triple 40% chlorhexidine varnish treatment did not affect plaque acidogenicity for more than 3 weeks. From comparison with a previous study, we conclude that the triple treatment with EC40 within 1 week was not more effective in reducing plaque acidogenicity than the single one.

Study of the clinical usefulness of a dental drug system for selective reduction of mutans streptococci using a case series

The aim of this study was to evaluate the clinical efficacy and safety of a dental drug delivery system (3DS) for the selective reduction of mutans streptococci. Twenty patients with high levels of mutans streptococci in saliva participated. The efficacy of 0.2% chlorhexidine (CHX) delivered by 3DS in reducing the salivary levels of mutans streptococci compared with total streptococci and lactobacilli was investigated. Each subject was treated by professional mechanical tooth cleaning (PMTC) and subsequently individual trays with CHX for 5 min. Salivary bacterial samples were taken at the baseline and weeks 1-12. A significant reduction in the colony count of mutans streptococci was observed during the first 4 weeks compared with the baseline count, while no significant decrease in the count of total streptococci or lactobacilli was found during 12 weeks. In particular, the proportion of mutans streptococci in total streptococci remained low after 12 weeks. Our results indicate that the new 3DS used in combination with PMTC appears to be a promising intraoral drug delivery system which, when used with a low CHX concentration selectively, effectively reduces mutans streptococci in the oral cavity with no adverse effects.

Chlorhexidine varnishes: a review

BACKGROUND

Of all chemical plaque control agents, chlorhexidine digluconate has proven to be the most effective and safe. Since 1964, varnishes have been used for local delivery of fluor and are reported to be an effective and easy to use vehicle. During the past decade, varnishes for local delivery of antimicrobial agents have been developed and investigated in vitro and in vivo.

AIM

In this paper, the existing literature on the use of 3 different chlorhexidine varnishes in different fields in dentistry is reviewed.

METHOD

In vitro results concerning the release of the antimicrobial agents are compared for the 3 different varnish formulations.

RESULTS AND CONCLUSION

Clinical reports on the efficacy of controlled-release systems in altering cariogenic and periodontopathic microflora are summarized.

Prevention of pit and fissure caries using an antimicrobial varnish: 9 month clinical evaluation

OBJECTIVE

The purpose of this study was to determine whether Cervitec--a chlorhexidine--containing varnish could reduce the development of pit and fissure caries in children.

METHODS

One hundred children each in age groups 7-8 and 12-14 years were selected from schools in Riyadh, Saudi Arabia. To be included in the study, each child had to have at least two sound contra-lateral first or second permanent molars with deep fissures. A split mouth method was used with one test tooth and one control within the same jaw. The left or the right side was selected randomly for test or control. The plaque samples from the occlusal surfaces of the test and control and the saliva samples were collected at baseline examination and after 9 months to estimate the number of Streptococcus mutans by the strip mutans method of Jensen and Bratthall (Jensen B, Bratthall D. A new method for the estimation of mutans streptococci in human saliva. Journal of Dental Research 1989;68:468-471). Cervitec varnish containing 1% chlorhexidine (CHx) and thymol was applied at baseline, at 3-4 months and at 6 months to the test tooth after isolation while the control had prophylaxis using cotton pellet in water each time the varnish was applied to the test tooth. Caries examination of the test and control followed after 9 months, according to the criteria and methods of WHO (World Health Organization. Oral Health Surveys. Basic Methods 4th ed., Geneva, WHO 1997). The blind technique was used in the diagnosis of caries and in the examination of the S. mutans count at the end of the study.

RESULTS

Ninety four of the 7-8 year old and 86 of the 12-14 year old children completed the study. The results showed that the caries increment in both control groups of teeth after 9 months is significantly higher than in the test teeth (McNemar test: chi2 = 11.60, P < 0.001). The rate of caries development in a fissure was significantly correlated to the plaque mutans score of that fissure and there was considerable reduction in the S. mutans count of the plaque in the test teeth compared with the control (Spearman Rank Correlation: P < 0.001).

CONCLUSION

It is concluded that the CHx varnish reduced the development of fissure caries significantly.

The effect of parabens in a mouthwash and incorporated into a sustained release varnish on salivary bacteria

OBJECTIVES

The purpose of this study was to evaluate the antimicrobial efficacy of parabens, in a mouthwash and in a slow release device, against cariogenic bacteria in the oral cavity.

METHODS

Parabens were formulated in a mouthwash or in a topical slow release varnish preparation. In two separate studies, volunteers were asked to use the mouthwash or the slow release varnish applied in a personal night guard device. The levels of mutans streptococci (MS), Lactobacilli (LB) and total cultivated bacteria were measured before and after using the mouthwash or the slow release varnish.

RESULTS

The mouthwash containing parabens had a minor and a short-term effect on MS and LB counts in human saliva. The use of slow release varnish containing parabens, applied in a night guard, had a prolonged antibacterial effect on both MS and LB counts.

CONCLUSIONS

Parabens in a mouthwash had little effect on oral bacteria counts; however, paraben in the slow release device had a significant and an extended effect in reducing oral bacteria. Although substantial reductions in oral bacterial counts were recorded after the use of parabens in a slow release device, this effect could probably be enhanced by an improved pharmaceutical formulation.

Effects of chlorhexidine on the bacterial colonization and degradation of dentin and completely demineralized dentin in situ

The effects of 0.2% chlorhexidine on selected plaque microorganisms were studied in an intraoral dentin caries model. In 8 individuals wearing partial dentures, sound and completely demineralized dentin specimens were placed consecutively in 2 periods of 4 weeks, respectively. Throughout the experimental period, the specimens were treated 2 x daily with 0.2% chlorhexidine; control specimens were treated with water. Plaque accumulation on the specimens was left undisturbed. No protection against demineralization of the dentin or degradation of the dentin collagen by the chlorhexidine treatment was observed. The chlorhexidine treatment did not result in a reduction of the total cultivable flora when compared with the control specimens. A significant reduction of mutans streptococci and total streptococci recovered from completely demineralized dentin treated with chlorhexidine was observed, but the proportions of Actinomyces and lactobacilli were not affected significantly. It is speculated that areas of exposed roots, which are difficult to reach by oral hygiene measurements, such as approximal surfaces, will not be protected by a 0.2% chlorhexidine mouthrinse against the caries process.

Effect of chlorhexidine gel treatment on the prevalence of mutans streptococci and lactobacilli in patients with impaired salivary secretion rate

The potential pathogenic role of mutans streptococci in the etiology of dental caries is well-documented. Mutans streptococci are sensitive to chlorhexidine (CHX), and several methods for the clinical use of CHX have been described. An important target group for caries-preventive measures is patients with impaired salivary secretion due to the use of therapeutic drugs such as psychotropics. The aim of the present study was to compare two methods for antimicrobial treatment in such patients. Twenty-four volunteering patients at a hospital clinic were randomly divided into three groups: Group A, in which each participant was treated with 10% CHX gel in gel trays on two consecutive days, followed by application of a fluoride varnish; Group B, in which the patients were treated with the same CHX gel as above; and Group C, which was used as a control. After treatment, there was a reduction of mutans streptococci in the two groups treated with CHX. In group A, the sames collected one, three, and five weeks after the treatment were significantly lower than baseline values. No clearcut reduction of the number of mutans streptococci was observed in the subjects not treated with CHX. These data indicate that treatment with CHX gel in gel trays is superior to polishing the teeth with CHX gel. From a clinical point of view, our observations suggest that it is important to monitor the effect of antimicrobial treatment individually in order to optimize preventive programs in patients with impaired salivary secretion.

From the art of filling teeth to the science of dental caries prevention: a personal review

The journey from the art of filling teeth to the science of prevention is reviewed. First, a private winding road is described that produced some new methods of value in risk assessment, treatment of the causes of dental caries, and prevention of the disease. The description illustrates the importance of monitoring the effects of different measures. Next, the new knowledge and methods that form the primary basis of prevention on a large scale are reviewed. They represent a golden era in caries research and form a solid ground for the prevention of dental caries and for the treatment of the causes of disease. The prevalence and incidence of dental caries has fallen not only among schoolchildren, but also among adults in developed countries. Improvement in dental health is due to the successful application of new knowledge-it has not happened by chance. New or improved opportunities for prevention could lead to a further reduction in dental caries. The problem is to find ways to stimulate both dentists and patients to use them. Finally, the next part of the journey is discussed. In some countries the journey probably will be an uphill struggle; in others, it could be fairly undulating, eventually leading to further declines in dental caries.

Control of specific plaque bacteria

The Specific Plaque Hypothesis posits that particular bacteria are of unique importance in the etiology of dental caries and periodontal diseases, and a logical conclusion is that these bacteria should be the targets for our 'magic bullets' in devising plaque-control methods. This paper considers the development of preventive measures based on understanding of the significance of particular bacterial species and the properties of those bacteria. Knowledge of the importance of specific organisms as mediators of disease and molecular studies on the properties of potential virulence factors may reveal potential targets for inhibition, blocking by synthetic analogues, or functional inactivation by antibodies.

Potential efficacy of chlorhexidine against mutans streptococci and human dental caries

Chemotherapeutic agents have been considered as having potential for the prevention of dental caries. Several substances have been evaluated as possible candidates, but no antimicrobial agent, with the exception of fluoride, has received as much experimental attention as the bisbiguanide chlorhexidine. This substance represents, so far, the most effective and best-documented agent. To be effective against caries, therapeutic dosages of the antimicrobial agent have to be given for a sufficient but finite time period to sites with established cariogenic plaque. In studies where this principle has been used, the aim has been to eliminate or strongly suppress the population of mutans streptococci. Of various antimicrobial agents and methods tested, the most persistent reduction of mutants streptococci has been achieved by chlorhexidine varnishes, followed by gels and mouthwashes. The best clinical effect resulting in a considerable caries reduction has been obtained when persons highly colonized with mutans streptococci have been treated with gels and when the results of the antimicrobial measures have been verified by microbiological examination.

Preventing dental caries: breaking the chain of transmission

Besides using all possible techniques to increase host resistance (fluoride, sealants) and decrease exposure to fermentable carbohydrates (for example, use of sugar substitutes), dentists must treat caries as infectious and transmissible. Antimicrobial agents are recommended.

The effect of chlorhexidine varnish treatment on salivary mutans streptococcal levels in child orthodontic patients

A chlorhexidine dental varnish was applied to the teeth of 26 children, ten to 17 years of age, in an attempt to limit the increase in colonization by mutans streptococci that normally accompanies the placement of fixed orthodontic appliances and to assess the acceptance of the application procedure. Despite the insertion of the appliances in the month following the varnish application, the numbers of detectable salivary mutans streptococci in the children were found to remain significantly lower than baseline values for seven months (p less than 0.01). Among the 26 children, 16 exhibited high counts (greater than 2.5 x 10(5) cfu/mL saliva) at baseline, but none exhibited such counts until three months post-treatment, when one child did. By seven months, eight children had high counts. No significant difference in effectiveness was observed between varnish formulations containing 10% or 20% chlorhexidine acetate, or between children of different ages or past caries experience. The lack of drop-outs and the results of a questionnaire indicated that acceptance of the treatment by the children was excellent. The study indicates that chlorhexidine varnish therapy was acceptable to the children and was effective in suppressing oral mutans streptococcal levels for long periods, even when used prior to the placement of fixed orthodontic appliances.