Abstract: In the first half of the 20th century, indices and methods of conducting surveys of the level of dental diseases were developed. Modern epidemiological studies began in the fifties and many reliable studies have been conducted after 1960. In the following decades, a substantial decline of caries prevalence was documented in the majority of the highly industrialized countries, with reductions of lifetime caries experience exceeding 75%. The decline comes to an end when low or very low levels of prevalence are reached. Children of low socioeconomic status and immigrants from outside Western Europe, however, generally have higher disease levels and may cause increases in caries prevalence. For this and other reasons, caries epidemiology will remain an indispensable part of dental public health.

Abstract: New technologies have provided novel insights into how dental plaque functions as a biofilm. Confocal microscopy has confirmed that plaque has an open architecture similar to other biofilms, with channels and voids. Gradients develop in areas of dense biomass over short distances in key parameters that influence microbial growth and distribution. Bacteria exhibit an altered pattern of gene expression either as a direct result of being on a surface or indirectly as a response to the local environmental heterogeneity within the biofilm. Bacteria communicate via small diffusible signalling molecules (e.g. competence-stimulating peptide, CSP; autoinducer 2); CSP induces both genetic competence and acid tolerance in recipient sessile cells. Thus, rates of gene transfer increase in biofilm communities, and this is one of several mechanisms (others include: diffusion-reaction, neutralization/inactivation, slow growth rates, novel phenotype) that contribute to the increased antimicrobial resistance exhibited by bacteria in biofilms. Oral bacteria in plaque do not exist as independent entities but function as a co-ordinated, spatially organized and fully metabolically integrated microbial community, the properties of which are greater than the sum of the component species. A greater understanding of the significance of dental plaque as a mixed culture biofilm will lead to novel control strategies.

Abstract: Acids of intrinsic and extrinsic origin are thought to be the main etiologic factors for dental erosion. There is evidence that acidic foodstuffs and beverages play a role in the development of erosion. However, the pH of a dietary substance alone is not predictive of its potential to cause erosion as other factors modify the erosive process. These factors are chemical (pKa values, adhesion and chelating properties, calcium, phosphate and fluoride content), behavioural (eating and drinking habits, life style, excessive consumption of acids) and biological (flow rate, buffering capacity, composition of saliva, pellicle formation, tooth composition, dental and soft tissue anatomy). The interplay between erosion and abrasion (specially oral hygiene practices) may be the main driver leading to the clinical manifestation of this disorder. Recommendations for patients at risk for dental erosion such as reducing acid exposure by reducing the frequency and contact of acids will be discussed.

Abstract: Saliva is essential for a lifelong conservation of the dentition. Various functions of saliva are implicated in the maintenance of oral health and the protection of our teeth: (i) The tooth surface is continuously protected against wear by a film of salivary mucins and proline-rich glycoprotein. (ii) The early pellicle proteins, proline-rich proteins and statherin, promote remineralization of the enamel by attracting calcium ions. (iii) Demineralization is retarded by the pellicle proteins, in concert with calcium and phosphate ions in saliva and in the plaque fluid. (iv) Several salivary (glyco)proteins prevent the adherence of oral microorganisms to the enamel pellicle and inhibit their growth. (v) The salivary bicarbonate/carbonate buffer system is responsible for rapid neutralization of acids. An overview is presented on the major antimicrobial systems in human saliva. Not only the well-known major salivary glycoproteins, including mucins, proline-rich glycoprotein and immunoglobulins, but also a number of minor salivary (glyco)proteins, including agglutinin, lactoferrin, cystatins and lysozyme, are involved in the first line of defense in the oral cavity. Besides, small cationic antimicrobial peptides, e.g. defensins, cathelicidin and the histatins, have come into focus. These are potentially suited as templates for the design of a new generation of antibiotics, since they kill a broad spectrum of microorganisms, while hardly evoking resistance, in contrast to the classical antibiotics.

Abstract: The metabolic activity in dental plaque, the biofilm at the tooth surface, is the driving force behind any loss of mineral from the tooth or cavity surface. The symptoms of the process (the lesion) reflect this activity and can be modified by altering the biofilm, most conveniently by disturbing it by brushing with a fluoride-containing toothpaste. The role of operative dentistry in caries management is to restore the integrity of the tooth surface so that the patient can clean. Thus, the question, 'how clean must a cavity be before restoration?' may be irrelevant. There is little evidence that infected dentine must be removed prior to sealing the tooth. Leaving infected dentine does not seem to result in caries progression, pulpitis or pulp death. However, some of the bacteria survive. What is their fate and if they are not damaging, why is this?

Abstract: This review focuses on the clinical interactions between patients and the dental team, not on caries prevention at a public health level. Many dentists no longer take a narrow surgical view seeking to apply interventive treatment as a one-off event at a certain trigger point of disease severity and the evidence that caries is an initially reversible, chronic disease with a known multi-factorial aetiology is being appreciated more widely. The caries process should be managed over time in an individualized way for each patient. Very few individuals can be considered to be truly 'caries free' when initial lesions as well as more advanced dentine lesions are considered. It is now very clear that, by itself, restorative treatment of the disease does not 'cure' caries. The caries process needs to be managed, in partnership with patients, over the changing challenges of a lifetime. The answer to the question posed in the title should be, in many cases, that we are ready to move to non-operative/preventive care (if we have not done so already). However, this should be for appropriate stages of lesion extent and in patients who respond to advice on recall frequency and preventive behaviours.

Abstract: The objectives were (1) to assess caries development, including the incidence and rate of lesion progression, in a Swedish cohort from adolescence to young adulthood and (2) to compare the caries inci

Abstract: A systematic review was performed of published data on the caries-inhibiting effect of preventive measures during orthodontic treatment with fixed appliances. The purpose was to develop evidence-based recommendations about the most effective means of preventing white spot lesions in orthodontic patients. The 15 studies included were divided into four groups based on comparable preventive measures: fluoride, chlorhexidine, sealants and bonding materials. The caries-inhibiting effect of the preventive measures was expressed by the prevented fraction (PF). The overall PF of the fluoride-releasing bonding materials was 20% (SEM 0.09). This effect was, however, not statistically significant. It was impossible to calculate an overall PF for the other preventive measures, but the tendency of their caries-inhibiting effect has been described. The use of toothpaste and gel with a high fluoride concentration of 1,500-5,000 ppm or of complementary chlorhexidine during orthodontic treatment showed a demineralisation-inhibiting tendency. The use of a polymeric tooth coating on the tooth surface around the brackets showed almost no demineralisation-inhibiting effect. Many publications had to be excluded from this systematic review because of improper research designs. Future clinical trials are needed to give evidence- based advice on the optimal caries-prevention strategy.

Abstract: Xerostomia, the subjective sensation of dry mouth, occurs when the salivary flow rate is less than the rate of fluid loss from the mouth by evaporation and by absorption of water through the oral muco

Abstract: The ultimate goal of a regenerative pulp treatment strategy is to reconstitute normal tissue continuum at the pulp-dentin border, regulating tissue-specific processes of tertiary dentinogenesis. Experimental investigations in mature teeth have shown that a network of extracellular matrix molecules and growth factors signal tertiary dentinogenesis. Application of dentin matrix components or growth factors in deep dentinal cavities stimulated up-regulation of biosynthetic activity of primary odontoblasts (reactionary dentin formation). Pulp-capping studies with a broad spectrum of biological agents, including growth factors and extracellular matrix molecules, showed formation of osteodentin and/or tertiary dentinogenesis (reparative dentin formation). Promising biologically active substances should be subjected to careful evaluation in well-designed preclinical investigations as well as in long-term clinical trials before their introduction in clinical practice.

Abstract: This review aims to outline the effects of fluoride on the biological processes involved in the formation of tooth tissues, particularly dental enamel. Attention has been focused on mechanisms which, if compromised, could give rise to dental fluorosis. The literature is extensive and often confusing but a much clearer picture is emerging based on recent more detailed knowledge of odontogenesis. Opacity, characteristic of fluorotic enamel, results from incomplete apatite crystal growth. How this occurs is suggested by other changes brought about by fluoride. Matrix proteins, associated with the mineral phase, normally degraded and removed to permit final crystal growth, are to some extent retained in fluorotic tissue. Fluoride and magnesium concentrations increase while carbonate is reduced. Crystal surface morphology at the nano-scale is altered and functional ameloblast morphology at the maturation stage also changes. Fluoride incorporation into enamel apatite produces more stable crystals. Local supersaturation levels with regard to the fluoridated mineral will also be elevated facilitating crystal growth. Such changes in crystal chemistry and morphology, involving stronger ionic and hydrogen bonds, also lead to greater binding of modulating matrix proteins and proteolytic enzymes. This results in reduced degradation and enhanced retention of protein components in mature tissue. This is most likely responsible for porous fluorotic tissue, since matrix protein removal is necessary for unimpaired crystal growth. To resolve the outstanding problems of the role of cell changes and the precise reasons for protein retention more detailed studies will be required of alterations to cell function, effect on specific protein species and the nano-chemistry of the apatite crystal surfaces.

Abstract: 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 the

Abstract: Caries diagnosis is the art or act of identifying a disease from its signs and symptoms. This is distinct from the detection of the signs and symptoms themselves. The diagnosis forms the basis for making informed treatment decisions. Hence, if there is no diagnostic step expressed in terms of the probability of present and future occurrence of disease, practitioners may resort to treatments guided by previous experiences with similar clinical manifestations. This paper reviews various methodological aspects of caries diagnostic testing. It is concluded that rather than continuing to search for the truth of the diagnosis, it may be more informative to consider the consequences of the diagnosis. This view is supported by results from caries-preventive trials in which the activity of carious lesions has been monitored longitudinally over years.

Abstract: The aim of this paper was to examine recent evidence for the effect of the antibacterial approach to prevent and control caries with special reference to the use of chlorhexidine (CHX). Existing information from the mid 1990s provided limited evidence for the effectiveness of CHX gels, rinses and toothpaste in preventing caries in permanent teeth of children and adolescents. An updated literature search on CHX intervention in controlled clinical trials from 1995 to May 2003 unveiled 22 studies covering over 4,500 patients with clinical caries as end point. The vast majority (n = 21) were dealing with CHX-containing varnishes. Since the studies exhibited disparities in design, diagnosis and intervention, the findings were subgrouped with respect to caries type and localization. According to the ranking system of the Swedish Council on Technology Assessment in Health Care, the evidence for an anticaries effect of CHX varnishes was rated as inconclusive for caries-active schoolchildren and adolescents with regular fluoride exposure. Regarding fissure caries, a preventive effect of CHX varnishes was demonstrated in 4 studies out of 5 when compared to no treatment in children with low fluoride exposure. The evidence for arresting root caries in dry-mouth patients and frail elderly subjects was inconclusive. In conclusion, the evidence from the recent literature was inconclusive for the use of CHX varnishes for caries prevention in risk groups.

Abstract: The actual mechanism of fluoride action is still a subject of debate. A dogma has existed for many decades, that fluoride has to be ingested and acts mainly pre-eruptively. However, recent studies concerning the systemic effect of fluoride supplementation concluded that the caries-preventive effect of fluoride is almost exclusively posteruptive. Moreover, epidemiologists have cast doubt on the validity of the 'old' studies dealing with fluoride use. The concept of the posteruptive fluoride effect is supported by in vitro and in situ investigations demonstrating that the mode of action of fluoride can be attributed mainly to its influence on de- and remineralization kinetics of dental hard tissues. Therefore, topical fluoride application (e.g. in the form of fluoridated dentifrices) should be encouraged. There are still important questions open that need to be answered despite existing knowledge about the caries-preventive effect of fluoride.

Abstract: When salivary output is reduced chronically to a significant extent, there is a marked increase in dental caries. As the role of saliva in protection of the oral hard tissue is well recognized, there have long been efforts to enhance salivary function in conditions with associated secretory hypofunction. The rationale is that by stimulating salivary output, caries and other oral complications will be reduced or eliminated. The most widely used method for increasing salivary function is a combination of masticatory and gustatory stimulation. A large number of systemic agents have also been proposed as secretagogues, but only a few have shown consistent salivary enhancing properties in well-designed, controlled trials. Pilocarpine has been shown to improve symptoms of oral dryness and to increase salivary output in patients with Sjogren's syndrome and postradiation xerostomia. Recently, cevimeline has shown significant salivary enhancement in Sjogren's syndrome. Pilocarpine and cevimeline have a similar mechanism of action, side effect profile and duration of activity. No secretagogues have been linked directly in clinical trials to either caries prevention or a reduction in the existing caries rate of salivary dysfunction patients. Improved secretagogues are needed, with fewer side effects, increased duration of activity and greater potency. Future research directions include gene therapeutic approaches to direct salivary growth and differentiation or modify remaining tissues to promote secretion, creation of a biocompatible artificial salivary gland and salivary transplantation. With improved secretagogues, the effects of conditions that result in reduced salivary function and increased caries will be ameliorated.

Abstract: The term biofilm is increasingly replacing 'plaque' in the literature, but concepts and existing paradigms are changing much more slowly. There is little doubt that biofilm research will lead to more realistic perception and interpretation of the physiology and pathogenicity of microorganisms colonizing plaques in the oral cavity. There is clear evidence that the genotypic and phenotypic expression profiles of biofilm and planktonic bacteria are different. Several techniques are available today to study multispecies biofilms of oral bacteria, each having its particular advantages and weaknesses. We describe a biofilm model developed in Zurich and demonstrate a number of applications with direct or indirect impact on prophylactic dentistry: spatial arrangement and associative behavior of various species in biofilms; multiplex fluorescent in situ hybridization analysis of oral bacteria in biofilms; use of the biofilm model to predict in vivo efficacy of antimicrobials reliably; mass transport in biofilms; de- and remineralization of enamel exposed to biofilms in vitro. The potential of biofilm experimentation in oral biology has certainly not yet been fully exploited and dozens of possible interesting applications could be investigated. The overall physiological parameters of multispecies biofilms can be measured quite accurately, but it is still impossible to assess in toto the multitude of interactions taking place in such complex systems. What can and should be done is to test hypotheses stemming from experiments with planktonic cells in monospecies cultures. In particular, it will be interesting to investigate the relevance to biofilm composition and metabolism of specific gene products by using appropriate bacterial mutants.

Abstract: The caries-preventive effects of fluoride are beyond any reasonable doubt! Inclusion of fluoride use in caries prevention protocols has resulted in significant reduction in caries prevalence in the majority of the population. Nevertheless, even in low-caries prevalence populations up to 20% of individuals may suffer to an unacceptable degree from caries. In the history of caries research various phases can be discerned. Starting with the initial - laboratory - studies to reveal the mode of action of fluoride, attention later shifted to intra-oral studies and in situ product testing. Currently much emphasis is given to evidence-based dentistry and guidelines for clinical practice, which trend has also focussed the research on fluoride and caries. While on some topics, such as the efficacy of fluoride toothpastes, evidence is convincing, additional research is indicated to resolve remaining questions. One such question is that of high-prevalence individuals for which a comprehensive research programme focussing both on caries aetiological and behavioural aspects should be further developed. Efforts should continue to be directed at improving our understanding of fluoride, in particular on topics where success so far has failed.

Abstract: The palatal aspect of upper anterior teeth appears to be one site of predilection for erosion This raises the question of whether abrasion of softened enamel and dentine by the tongue has a role in this process The aim of this study in vitro was to determine whether enamel and dentine specimens licked by the tongue after exposure to acid lost more tissue than when exposed to acid alone Flat enamel and dentine specimens were prepared from human third molars and taped to expose a window of tissue Three groups of specimens were exposed to citric acid for 10 min followed by 60 s tongue licking, ultrasonication or immersion in water Two further groups of enamel specimens were placed in a low erosive drink for 10 min with or without licking At the end of 5, 10 and 15 treatment cycles tissue loss was measured by profilometry Enamel loss was significantly greater with licking and ultrasonication compared to water immersion Dentine loss was greater with licking and ultrasonication compared to water immersion, but differences only reached significance for ultrasonication The low erosive drink produced one third of the citric acid erosion and licking had no effect The results suggest that the tongue could exert an abrasive effect on dental tissues softened by erosion, thereby increasing the overall loss of tooth substance

Abstract: In cross-sectional studies conducted in 1967, 1971, 1976, 1980, 1987, 1992, 1997 and 2002, 4-year-old children in Umea, a city in northern Sweden, were examined for dental caries and background factors such as oral hygiene habits, use of fluorides, and sugar consumption. The same methods and criteria have been used in each of the studies from 1967 to 2002. The number of children with caries had declined from 87% in 1967 to 42% in 1987, but then the decline levelled out. In 2002, 46% of the children had caries with a mean dmfs value of 2.0 +/- 3.6. Six percent of the children had 10 or more dmfs. Immigrant children had a higher caries prevalence (p < 0.01). A significant difference in the dmfs values was found in children according to tooth-brushing frequency (p < 0.01). Although the consumption of sugary products between meals increased between 1987 and 1997, no changes were noted from 1997 to 2002. In conclusion, no important changes in caries prevalence have taken place during the last 15 years. The frequency of tooth-brushing and immigrant background had a significant association with caries prevalence.

Abstract: The purpose of the present study was to determine the antibacterial activity of oolong tea extract on oral streptococci, including Streptococcus mutans and Streptococcus sobrinus, and to identify the response to its components. Antibacterial activity was found when the extract was added to S. mutans cells in chemically defined medium but not in complex broth media. Further, pretreatment with bovine serum albumin reduced the antibacterial activity. The extract showed antibacterial activity against all of the oral streptococci examined, with the highest activity against S. mutans MT8148R. This activity was found to originate from a monomeric polyphenol-rich fraction, and it was stronger than that of pure polyphenols. Moreover, some combinations of monomeric polyphenols showed the highest level of antibacterial activity. These results suggest that the antibacterial activity of oolong tea extract is caused by a synergistic effect of monomeric polyphenols, which can easily bind to proteins.

Abstract: Despite the well-known decline in the overall prevalence and incidence of dental caries in the Western societies, there remain persistent pockets of high caries. These are located generally within inner-city, low-socio-economic and immigrant populations throughout Europe and elsewhere. However, two other groups continue to record high caries: the very young and the elderly. Both show remarkable similarities in their characteristics and in many ways caries has the same aetiology, prevalence, treatment and preventive strategies. Both groups of people are mainly dependent on others for their care. Pre-school children are looked after by their parents who dictate their lives including choice of food, diet and oral care. The elderly are a mixed group. Firstly, there are the young elderly who are free living and totally look after themselves. Secondly, there are the elderly who are partially dependent and require support but mainly choose their own life-styles, including diet, and are responsible for their own oral care. Finally, there are the sick elderly who are dependent on carers who, just like the parents of the very young, dictate diet, food choice and provide oral care. It is mainly the third group of elderly, and to a lesser extent the second group, that present a problem of dental caries. These two groups of people pose a serious and difficult problem for dentistry in that they may present with high levels of dental caries and a significant percentage of the population are affected. In both instances the aetiology is multi-factorial and diet plays a major role. But the choice of diet may not be their own and they may often be victims of ignorance and poor practice by others. In addition, the prevention of dental caries is also dependent on the actions of their carers. Both the elderly and very young can be difficult to treat because of poor co-operation or behavioural problems. Thus, the dental profession is challenged by children and the elderly to devise not only workable prevention strategies but also methods of treatment and oral care.

Abstract: Synchrotron X-ray microtomography (XMT) was used to measure the linear attenuation coefficient (LAC) for 1.9-µm sidelength voxels within approximal brown spot lesions and sound human enamel. XMT demon

Abstract: To develop a bacterial demineralization model, we grew Streptococcus mutans biofilms in a constant depth film fermentor (CDFF) and studied the effects of sucrose pulsing frequency (SPF) in time on dentin demineralization. S. mutans biofilms were grown in dentin specimens with grooves and on dentin surface specimens for 20 days. During the experiments, 2% sucrose was pulsed either 4 or 8 times per day for periods of 30 min. Diluted brain-heart infusion medium containing 25 mM PIPES buffer and 1.5 mM CaCl2 was pulsed as the alternative growth medium. Specimens with intact biofilms were taken out on days 5, 12 and 20. The model was assessed by viable counts of the biofilm, mineral loss and lesion depth in the dentin specimens (by transversal microradiography) and pH measurements in the groove (by pH microelectrode). The results showed that biofilms formed on the dentin surface specimens were constant in viable counts for the low SPF, while this parameter tended to increase with time under the high SPF. Lesions with intact surfaces were formed and the lesion size increased significantly over time and increased significantly with increasing SPF. Typical Stephan curves were found after sucrose pulsing. The pH inside the groove returned to neutral under low SPF, but remained below 6.5 under high SPF. With the CDFF S. mutans biofilm model, lesions can be created in dentin within reasonable experimental time periods, as a result of the presence of a biofilm and in response to carbohydrate challenges.

Abstract: The major route of early acquisition of mutans streptococci in humans is a vertical transmission from mother to child. The purpose of this longitudinal study was to examine the acquisition, distributi

Abstract: The objective of this research was to evaluate the anticaries effectiveness of a low-dose (500 ppm F, low-NaF) sodium fluoride dentifrice, a high-dose (2,800 ppm F, high-NaF) sodium fluoride dentifric

Abstract: Studies performed in numerous laboratories over several decades have demonstrated the feasibility of immunizing experimental rodents or primates with protein antigens derived from Streptococcus mutans or Streptococcus sobrinus against oral colonization by mutans streptococci and the development of dental caries. Protection has been attributed to salivary IgA antibodies which can inhibit sucrose-independent or sucrose-dependent mechanisms of streptococcal accumulation on tooth surfaces according to the choice of vaccine antigen. Strategies of mucosal immunization have been developed to induce high levels of salivary antibodies that can persist for prolonged periods and to establish immune memory. Studies in humans show that salivary antibodies to mutans streptococci can be induced by similar approaches, and that passively applied antibodies can also suppress oral re-colonization by mutans streptococci. Progress towards practical vaccine development requires evaluation of candidate vaccines in clinical trials. Promising strategies of passive immunization also require further clinical evaluation.

Abstract: The role of Streptococcus mutans in the development of dental caries is well recognized. Important virulence factors include the glucosyltransferases (gtf), essential for production of glucans. We evaluated the anticariogenic effects of orally administered chicken anti-cell-associated (CA) Gtf antibodies in desalivated rats. The animals were infected with S. mutans MT8148R and treated with chicken anti-CA-Gtf egg yolk antibodies (IgY) or nonimmune egg yolk powder. Smooth surface lesions were significantly lower in the anti-CA-Gtf-treated group in comparison to the control groups. Sulcal surface caries was also decreased and of less severity. Our study suggests that chicken anti-CA-Gtf antibodies may have promise as a prophylaxis for high caries risk patients.

Abstract: Experience in practice has suggested that children with attention-deficit hyperactivity disorder (ADHD) tend to have higher numbers of diseased, missing and filled teeth (DMFT score) than children wit