C. van Loveren

Sugar Alcohols: What Is the Evidence for Caries-Preventive and Caries-Therapeutic Effects?

The most widely used sugar alcohols are: xylitol, sorbitol, mannitol, maltitol, lactitol and the products Lycasin ® and Palatinit ® . It is often claimed that xylitol is superior to the other sugar alcohols for caries control. This paper examines clinical studies on the caries-preventive and therapeutic effects of sugar alcohols with emphasis on sorbitol and xylitol. It is concluded that chewing sugarfree gum 3 or more times daily for prolonged periods of time may reduce caries incidence irrespective of the type of sugar alcohol used. It may be sufficient to do this only on school days. Sucking xylitol-containing candies or tablets may have a similar effect as chewing xylitol chewing gum. Clinical trials suggest greater caries reductions from chewing gums sweetened with xylitol than from gums sweetened with sorbitol. However, the superiority of xylitol was not confirmed in 2 out of 4 clinical trials comparing the caries-preventive effect of xylitol- with sorbitol-sweetened gums. The caries-preventive effects of polyol-containing gums and candies seem to be based on stimulation of the salivary flow, although an antimicrobial effect cannot be excluded. There is no evidence for a caries-therapeutic effect of xylitol. These conclusions are in line with those of recent reviews and with the conclusions of the Scientific Committee on Medicinal Products and Medical Devices of theThe most widely used sugar alcohols are: xylitol, sorbitol, mannitol, maltitol, lactitol and the products Lycasin and Palatinit. It is often claimed that xylitol is superior to the other sugar alcohols for caries control. This paper examines clinical studies on the caries-preventive and therapeutic effects of sugar alcohols with emphasis on sorbitol and xylitol. It is concluded that chewing sugar-free gum 3 or more times daily for prolonged periods of time may reduce caries incidence irrespective of the type of sugar alcohol used. It may be sufficient to do this only on school days. Sucking xylitol-containing candies or tablets may have a similar effect as chewing xylitol chewing gum. Clinical trials suggest greater caries reductions from chewing gums sweetened with xylitol than from gums sweetened with sorbitol. However, the superiority of xylitol was not confirmed in 2 out of 4 clinical trials comparing the caries-preventive effect of xylitol- with sorbitol-sweetened gums. The caries-preventive effects of polyol-containing gums and candies seem to be based on stimulation of the salivary flow, although an antimicrobial effect cannot be excluded. There is no evidence for a caries-therapeutic effect of xylitol. These conclusions are in line with those of recent reviews and with the conclusions of the Scientific Committee on Medicinal Products and Medical Devices of the EU Commission.

Antimicrobial Activity of Fluoride and Its in vivo Importance: Identification of Research Questions

This manuscript discusses the antimicrobial activity of fluoride and its in vivo importance in order to identify research questions. There is a lot of information on mechanisms by which fluoride may iThis manuscript discusses the antimicrobial activity of fluoride and its in vivo importance in order to identify research questions. There is a lot of information on mechanisms by which fluoride may interfere with bacterial metabolism and dental plaque acidogenicity. The antimicrobial activity of fluoride products is enhanced when fluoride is associated with antimicrobial cations like Sn2+ and amine. It is not clear whether the antimicrobial mechanisms of fluoride are operating in vivo or even to what extent antimicrobial activity can contribute to caries prevention. This latter question may be the most important one in research.

Sealants in Dentistry: Outcomes of the ORCA Saturday Afternoon Symposium 2007

Sealants are a successful tool in caries prevention, but their role in preventive strategies after the caries decline has to be discussed. A survey of paediatric departments across Europe revealed that indications for pit and fissure sealants vary considerably, both nationally and internationally. Evidence for effectiveness of sealants in controlling caries in posterior teeth implies that sealants should be an integrated part of management of pit and fissure caries. Still, the indication for occlusal sealants seems to be shifting from primary prevention to a therapeutic decision for caries management of lesions in enamel and the outer part of the dentine. Sealants are also an interesting concept for caries management in approximal surfaces. Clinical trials suggest that novel techniques of sealing or infiltrating approximal lesions show promise. However, approximal sealing techniques are as complex to apply and time-consuming as approximal fillings. The article proposes guidelines for teaching on the use of sealants.

Sucrose and dental caries: a review of the evidence.

The aim of this study was to conduct a review of the literature to assess the relationship between quantity and pattern of sucrose use and dental caries. Using hand and electronic methods (MEDLINE, EMBASE) the literature was searched for epidemiological papers concerning any relationship of sugars and dental caries published since 1856. Superficial hand searching was carried out between 1856 and 1940, detailed hand searching 1940–1966 and electronic 1966–2007. Selection criteria were set based on, but not confined to, Cochran style standards. Investigations were categorized as A, fulfilling all criteria; B1, relevant fulfilling 19 of 23 criteria; B2, relevant but fulfilling only between 12 and 18 of the selection criteria; and C, all other papers. There were 95 papers meeting most (more than 12) or all of the selected criteria. Only 1 paper was graded A; 31 as B1. There were in addition some 65 as B2 and all the rest as C, which were discarded. There were a wide variety of study designs and those graded A or B1 comprised 23 ecological cross‐sectional, 7 cohort and 2 case control studies. Summary results showed that 6 papers found a positive, significant relationship of sugar quantity to dental caries, 19 of 31 studies reported a significant relationship of sugar frequency of use to dental caries. The balance of studies does not demonstrate a relationship between sugar quantity, but a moderately significant relationship of sugar frequency to dental caries.

The antimicrobial action of fluoride and its role in caries inhibition.

Despite a considerable amount of literature on the effects of fluoride in dental plaque, several urgent questions remain unanswered, such as: Does the inhibiting effect of fluoride on dental plaque metabolism contribute to caries prevention? Does adaptation of plaque to fluoride affect its cariogenicity? Single applications of fluoride directly to dental plaque reduced acid production. Also, fluoride dissolving from topically treated enamel reduced the acid production in covering layers of oral bacteria in vitro. The effects of both treatments were only of short duration and may not be relevant to caries prevention in vivo. In contrast, daily applications of fluoride resulted in a reduction of the acidogenicity of dental plaque even 8-12 h after the treatment. Such a reduction is likely to contribute to caries prevention. But it has to be realized that when plaque reaches saturation with respect to fluoridated calcium (phosphate) precipitates, enamel becomes insoluble and any antimicrobial effect becomes irrelevant. Still lacking are data on the antimicrobial effects of fluoride regimens normally used in home care, in weekly rinsing programs in schools, or treatments applied professionally every six months. Adaptation of Streptococcus mutans to fluoride has been suggested to reduce the cariogenic potential of the cells. In vitro-induced fluoride-resistant strains were less cariogenic in rats, and the velocity of acid production in vitro was reduced at constant pH greater than 5.5. Despite the ability of oral bacteria to adapt to fluoride, evidence of adaptation in dental plaque of normal subjects resulting in a reduced cariogenic potential has not yet been demonstrated.Despite a considerable amount of literature on the effects of fluoride in dental plaque, several urgent questions remain unanswered, such as: Does the inhibiting effect of fluoride on dental plaque metabolism contribute to caries prevention? Does adaptation of plaque to fluoride affect its cariogenicity? Single applications of fluoride directly to dental plaque reduced acid production. Also, fluoride dissolving from topically treated enamel reduced the acid production in covering layers of oral bacteria in vitro. The effects of both treatments were only of short duration and may not be relevant to caries prevention in vivo. In contrast, daily applications of fluoride resulted in a reduction of the acidogenicity of dental plaque even 8-12 h after the treatment. Such a reduction is likely to contribute to caries prevention. But it has to be realized that when plaque reaches saturation with respect to fluoridated calcium (phosphate) precipitates, enamel becomes insoluble and any antimicrobial effect becomes irrelevant. Still lacking are data on the antimicrobial effects of fluoride regimens normally used in home care, in weekly rinsing programs in schools, or treatments applied professionally every six months. Adaptation of Streptococcus mutans to fluoride has been suggested to reduce the cariogenic potential of the cells. In vitro-induced fluoride-resistant strains were less cariogenic in rats, and the velocity of acid production in vitro was reduced at constant pH greater than 5.5. Despite the ability of oral bacteria to adapt to fluoride, evidence of adaptation in dental plaque of normal subjects resulting in a reduced cariogenic potential has not yet been demonstrated.

The Effect of Chlorhexidine Varnish on Root Caries: A Systematic Review

Objective: The aim of this study was to systematically review the present literature on the effect of chlorhexidine varnish (CHX-V) on root caries. Materials and Methods: The MEDLINE-PubMed, the Cochrane-CENTRAL and EMBASE databases were searched through December 2010 to identify any appropriate studies. Root caries incidence and root caries activity were selected as outcome variables. Results: An independent screening of the unique titles and abstracts of 24 MEDLINE-PubMed, 14 Cochrane-CENTRAL and 18 EMBASE papers resulted in 6 publications that met the eligibility criteria. Data extraction provided no conclusive evidence that the application of CHX-V is effective in patients when regular professional oral prophylaxis is performed. If effective, the 40% CHX-V was found to provide a benefit over a control or fluoride varnish. CHX-V at lower concentrations (1 and 10%) may provide protection against root caries in high-risk patients (such as geriatric and xerostomia patients) in the absence of regular professional oral prophylaxis. Conclusion: Within the limitations of this review, it may be concluded that in the absence of regular professional tooth cleaning and oral hygiene instructions, CHX-V may provide a beneficial effect in patients in need of special care. The strength of this recommendation is graded as ‘weak’.

Similarity of Bacteriocin Activity Profiles of Mutans Streptococci within the Family When the Children Acquire the Strains After the age of 5

It has been shown that there is a window of infectivity for mutans streptococci between the ages of 19 and 31 months, when many children acquire mutans streptococci transmitted from their mothers. Part of the children that escape this window acquire mutans streptococci at a later age. In this group, maternal transmission is expected to be less prevalent. The present study compared the bacteriocin activity profiles of mutans streptococci isolated from mothers, fathers and children when the children acquired the mutans streptococci between the ages of 5 and 11. Twelve families were randomly selected from a group of 11–year–old children who were known to have acquired mutans streptococci during this age period. From the saliva of the mothers (n = 12), fathers (n = 8) and children (n = 12) approximately 30 mutans streptococci strains were isolated. All isolates were tested twice for bacteriocin activity against 21 indicator strains with a double–layer technique. Bacteriocin activity of strains was considered to be different when the number of strains against which bacteriocin was produced differed >1 or when the width of one or more inhibition zones differed ≥4 mm. In 7/12 mother–child pairs similar profiles were found. In the 8 father–child pairs similar profiles were only found on 2 occasions. In these 2 families, all 3 ( mother, father and child) harboured strains with a similar profile. In 4/8 father–mother pairs similar profiles were found. There was no correlation between the prevalence of mutans streptococci strains, the number of indicator strains against which the strains made bacteriocin, nor the mean size of the inhibition zones and the presence of similarity of bacteriocin activity profiles of mutans streptococci within the family members. The results show that even when a child acquires mutans streptococci after the age of 5, there may be similarity between mutans streptococci in mother, father and child, indicating that transmission between the family members occurs.

Prognosis of Caries Increment with Past Caries Experience Variables

This study aimed to select past caries experience variables as caries predictors and to compare their prognostic accuracy with the variables used in a method of caries prognosis developed in a Swiss child population. The data used for the analyses originated from an 8–year longitudinal study starting in 1980 on caries of 7.5–year–old Dutch children. Stepwise logistic regression analyses provided predictor variables. The newly introduced variables D23fi, D123fi and D23pifi were interchangeable and the most powerful caries predictors. For the sake of uniformity and ease of application, D23fi (number of fissures of the permanent first molar with non–cavitated or cavitated caries lesions) was chosen as the first variable in the logistic regression equations. The gain in accuracy of the second and third predictor variables (number of sound primary molars and the number of buccal and lingual smooth surfaces of the permanent first molar with non–cavitated or cavitated caries) in the regression equations was limited. The D1 condition of surfaces could be omitted from the prediction models. The present forced three–predictor–regression equations for 7.5–, 9.5– and 11.5–year–old children were evaluated to assess their prognostic performance by using the area under the ROC curve as a measure of prognostic quality. For the present regression equations, the area under the ROC curve was 81–87%, which was higher compared to the Swiss regression equations for caries prognosis.This study aimed to select past caries experience variables as caries predictors and to compare their prognostic accuracy with the variables used in a method of caries prognosis developed in a Swiss c

Caries-Preventive Agents Induce Remineralization of Dentin in a Biofilm Model

The aim was to study remineralization in dentin underneath a biofilm. This was done in a constant depth film fermentor (CDFF) which was modified so that two treatments can be applied simultaneously in one experiment. Forty-five Streptococcus mutans biofilms were grown in grooves in dentin. Growth medium (3.7 g/l BHI, 1.5 mM calcium and 25 mM PIPES) was administered alternately with 2% sucrose pulsing 4 × 30 min/day. Fluoride at 135 ppm as NaF only or in a mixture with 0.2% chlorhexidine was applied for 2 × 5 min/day. The treatments started 5 days after inoculation and lasted 15 days. Five specimens per group were removed at various time points. The biofilms were checked for viability (by plating) and acid content (by capillary electrophoresis). The dentin specimens were analysed for mineral loss and lesion depth (by transversal microradiography). Fluoride treatment had no effect on the viability but reduced lactic acid production by 75%. The mixture treatment reduced the viability by 80% and the lactic acid content by 93% on the first day and later reduced the two parameters to below the detection limits. Significant differences in changes in mineral loss and lesion depth were observed between the treatment groups. Partial remineralization but deeper lesions were observed in the fluoride group, while nearly complete remineralization was seen in the mixture group. In conclusion, the CDFF S. mutans biofilm model can be used as a de- and remineralization biofilm model, and the split mode is particularly suitable for testing caries-preventive agents.

Experts’ Opinions on the Role of Diet in Caries Prevention

A questionnaire was sent to 54 experts in preventive dentistry in 23 European countries in order to make an inventory of existing national dietary guidelines for the prevention of dental caries. In addition, the experts were asked to give their personal opinion on several issues concerning the relationship between diet and dental caries. Forty-five experts from 20 countries returned the questionnaire. In 13 European countries dietary guidelines for caries prevention were available issued by a National (Dental) Association or a Government Body. All guidelines emphasised a reduction of the frequency of intakes of cariogenic foods. Two of them included a threshold level for the amount of sugar. When asked for their personal opinions, almost all experts mentioned reduction of frequency of ‘cariogenic’ intakes as the principal dietary messages for caries prevention. Four experts, however, explicitly mentioned that proper oral hygiene with fluoride toothpaste is more important. There was no agreement among the experts about a daily number of cariogenic intakes in between meals that can be regarded as safe, nor whether the message: ‘Use products with sugar substitutes’ should be part of the dietary guidelines for the prevention of dental caries. There was no agreement amongst experts on preventive dentistry in Europe on the contemporary validity of the paradigm: ‘Sucrose is the arch criminal of dental caries.’ Taking the variation in opinions into account and the fact that a balanced diet may lead to a moderate eating and snacking frequency, the authors propose that the emphasis on good versus bad foods for caries prevention should be replaced by an emphasis on good versus bad diets.