Changing paradigms in concepts on dental caries: consequences for oral health care

The impact of MUC5B gene on dental caries

OBJECTIVE

To identify the impact of MUC5B polymorphisms on dental caries.

METHODS

A case-control study was performed with patients recruited at Pontifícia Universidade Católica do Paraná. These individuals were aged 12 years old or more. Dental caries was diagnosed using the International Caries Detection and Assessment System, and the effects of socioeconomic, dietary, and hygiene factors on dental caries were investigated. Furthermore, buccal cells were collected, and their DNA was extracted and amplified using PCR. Uni-, bi-, and multivariate analyses were performed.

RESULTS

Two hundred patients were recruited, 100 were assigned to the case group and 100 to the control group. In the bivariate analysis, the following variables showed significant results: ethnicity (p = .008), biofilm (p < .001), and gingivitis (p < .001). The MUC5B gene affected dental caries with the markers rs2735733 (p < .001), rs2249073 (p < .001), and rs2857476 (p < .001). In the multivariate analysis, the biofilm variable remained significant (p = .026), as did the following markers from the MUC5B gene: rs2735733 (p = .019), rs2249073 (p < .025), and rs2857476 (p < .005).

CONCLUSION

Genetic variations in the MUC5B gene can influence dental caries.

Fluoride supplementation (with tablets, drops, lozenges or chewing gum) in pregnant women for preventing dental caries in the primary teeth of their children

BACKGROUND

Dental caries (tooth decay) is one of the most common chronic childhood diseases. Caries prevalence in most industrialised countries has declined among children over the past few decades. The probable reasons for the decline are the widespread use of fluoride toothpaste, followed by artificial water fluoridation, oral health education and a slight decrease in sugar consumption overall. However, in regions without water fluoridation, fluoride supplementation for pregnant women may be an effective way to increase fluoride intake during pregnancy. If fluoride supplements taken by pregnant women improve neonatal outcomes, pregnant women with no access to a fluoridated drinking water supply can obtain the benefits of systemic fluoridation.

OBJECTIVES

To evaluate the effects of women taking fluoride supplements (tablets, drops, lozenges or chewing gum) compared with no fluoride supplementation during pregnancy to prevent caries in the primary teeth of their children.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 25 January 2017); the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 11) in the Cochrane Library (searched 25 January 2017); MEDLINE Ovid (1946 to 25 January 2017); Embase Ovid (1980 to 25 January 2017); LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; 1982 to 25 January 2017); and CINAHL EBSCO (Cumulative Index to Nursing and Allied Health Literature; 1937 to 25 January 2017). We searched the US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform for ongoing trials to 25 January 2017. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of fluoride supplements (tablets, drops, lozenges or chewing gum) administered to women during pregnancy with the aim of preventing caries in the primary teeth of their children.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts (when available) of all reports identified through electronic searches. Two review authors independently extracted data and assessed risk of bias, as well as evaluating overall quality of the evidence utilising the GRADE approach. We could not conduct data synthesis as only one study was included in the analysis.

MAIN RESULTS

Only one RCT met the inclusion criteria for this review. This RCT showed no statistical difference on decayed or filled primary tooth surfaces (dfs) and the percentage of children with caries at 3 years (risk ratio (RR) 1.46, 95% confidence interval (CI) 0.75 to 2.85; participants = 938, very low quality of evidence) and 5 years old (RR 0.84, 95% CI 0.53 to 1.33; participants = 798, very low quality of evidence). The incidence of fluorosis at 5 years was similar between the group taking fluoride supplements (tablets) during the last 6 months of pregnancy and the placebo group.

AUTHORS' CONCLUSIONS

There is no evidence that fluoride supplements taken by women during pregnancy are effective in preventing dental caries in their offspring.

Efficacy of resin infiltration of proximal caries in primary molars: 1-year follow-up of a split-mouth randomized controlled clinical trial

OBJECTIVE

The main purpose of this split month, randomized, controlled clinical trial was evaluate the efficacy of caries infiltration in controlling the progression of non-cavitated proximal lesions in primary molars. Anxiety and time required for the caries infiltration was also evaluated.

MATERIALS AND METHODS

Fifty healthy children, 5 to 9 years, presenting two primary molars with proximal caries lesions (1/2 of the enamel or outer 1/3 of dentin), were included. Lesions were randomly allocated to the test group (fluoridated toothpaste + flossing + infiltration) or to the control group (fluoridated toothpaste + flossing). Caries risk was based on the Cariogram model. The main outcome after 1-year radiographic follow up was assessed by an independent blinded examiner A facial image scale (FIS) was applied to assess dental anxiety and time required to perform the infiltration was recorded.

RESULTS

Of the sample, 92.9% corresponded to high or medium caries risk. In 42 patients (1-year follow up), caries progression was observed in 11.9% (5/42) of the test lesions compared with 33.3% (14/42) of the control lesions (p < 0.05). Five control and three test lesions progressed to the middle 1/3 of dentin and were restored. No side effects were observed. Anxiety was both low before and after the treatment, and mean time required for the infiltration was 11.29 min (± 1.16 min).

CONCLUSIONS

Caries infiltration of proximal caries lesions in primary molars is significantly more efficacious than standard therapy alone (fluoride toothpaste + flossing).

CLINICAL RELEVANCE

Caries infiltration is an applicable and well-accepted method be used in children, representing a promising micro-invasive approach.

Sugars and beyond. The role of sugars and the other nutrients and their potential impact on caries

The traditional concept of caries as a multifactorial transmittable and infectious disease has been challenged. Novel conceptual ideas have come to add to the complexity of this highly prevalent disease worldwide. Current etiological understanding of the disease has emphasized the pivotal role of sugars in caries. In fact, current definition points toward an ecological disease caused by the commensal microbiota that under ecological imbalances, mainly due to high and or frequent sugars consumption, creates a state of dysbiosis in the dental biofilm. This modern conceptual idea, however, tends to underrate a key issue. As humans are omnivore and consume a mix diet composed by a multitude of substances, the role of the diet in caries must not be restricted only to the presence of fermentable sugars. This review explores the contribution of other food components, ubiquitous to the diet, mostly as potentially protective factors. Anticaries nutrients might determine an environmental change, affecting the ecology of the oral microbiome and partially mitigating the effect of sugars. Understanding the function of the food usually consumed by the people will contribute new knowledge on the mechanisms associated with the onset of caries, on new caries risk variables and on potential novel strategies for the prevention and treatment of the disease.

DENTAL ENAMEL FORMATION AND IMPLICATIONS FOR ORAL HEALTH AND DISEASE

Dental enamel is the hardest and most mineralized tissue in extinct and extant vertebrate species and provides maximum durability that allows teeth to function as weapons and/or tools as well as for food processing. Enamel development and mineralization is an intricate process tightly regulated by cells of the enamel organ called ameloblasts. These heavily polarized cells form a monolayer around the developing enamel tissue and move as a single forming front in specified directions as they lay down a proteinaceous matrix that serves as a template for crystal growth. Ameloblasts maintain intercellular connections creating a semi-permeable barrier that at one end (basal/proximal) receives nutrients and ions from blood vessels, and at the opposite end (secretory/apical/distal) forms extracellular crystals within specified pH conditions. In this unique environment, ameloblasts orchestrate crystal growth via multiple cellular activities including modulating the transport of minerals and ions, pH regulation, proteolysis, and endocytosis. In many vertebrates, the bulk of the enamel tissue volume is first formed and subsequently mineralized by these same cells as they retransform their morphology and function. Cell death by apoptosis and regression are the fates of many ameloblasts following enamel maturation, and what cells remain of the enamel organ are shed during tooth eruption, or are incorporated into the tooth's epithelial attachment to the oral gingiva. In this review, we examine key aspects of dental enamel formation, from its developmental genesis to the ever-increasing wealth of data on the mechanisms mediating ionic transport, as well as the clinical outcomes resulting from abnormal ameloblast function.

Sweet Taste Perception and Dental Caries in 13- to 15-Year-Olds: A Multicenter Cross-Sectional Study

Dietary habits and, in particular, the intake frequency of sucrose are of major importance for the development of dental caries. The perception of sweet taste is believed to have an influence on sucrose intake and therefore affects the predisposition to dental caries. The aim was to study the caries experience and sweet taste perception and to further analyze the possible relationship between the 2 tested variables in 13- to 15-year-old children from 3 different geographical areas. A cross-sectional survey comprising 669 children (220 Italian, 224 Mexican, and 225 Saudi Arabian) was conducted. The children were examined in their school setting. A sweet taste perception level was determined by the sweet taste threshold (TT) and sweet taste preference (TP). The sweet test was performed with sucrose solutions varying in concentration from 1.63 to 821.52 g/L. The International Caries Detection and Assessment System (ICDAS) and DMFS indices were used to diagnose caries. The highest mean value for TT was found for Italian children followed by Saudi and Mexican. Saudi schoolchildren showed the highest mean values for TP and DMFS, followed by Italian and Mexican. A statistically significant difference for TP, TT, DMFS, and initial caries was found between the 3 countries. A weak yet positive correlation was found between taste perception (TT and TP) versus DMFS and manifest caries in all 3 countries (r = 0.137-0.313). The findings of the present study showed a variation in sweet taste perception between the 3 countries, which may influence the caries outcome of the children in the individual countries.

Biofilm extracellular polysaccharides degradation during starvation and enamel demineralization

This study was conducted to evaluate if extracellular polysaccharides (EPS) are used by Streptococcus mutans (Sm) biofilm during night starvation, contributing to enamel demineralization increasing occurred during daily sugar exposure. Sm biofilms were formed during 5 days on bovine enamel slabs of known surface hardness (SH). The biofilms were exposed to sucrose 10% or glucose + fructose 10.5% (carbohydrates that differ on EPS formation), 8x/day but were maintained in starvation during the night. Biofilm samples were harvested during two moments, on the end of the 4th day and in the morning of the 5th day, conditions of sugar abundance and starvation, respectively. The slabs were also collected to evaluate the percentage of surface hardness loss (%SHL). The biofilms were analyzed for EPS soluble and insoluble and intracellular polysaccharides (IPS), viable bacteria (CFU), biofilm architecture and biomass. pH, calcium and acid concentration were determined in the culture medium. The data were analyzed by two-way ANOVA followed by Tukey's test or Student's t-test. The effect of the factor carbohydrate treatment for polysaccharide analysis was significant (p < 0.05) but not the harvest moment (p > 0.05). Larger amounts of soluble and insoluble EPS and IPS were formed in the sucrose group when compared to glucose + fructose group (p < 0.05), but they were not metabolized during starvation time (S-EPS, p = 0.93; I-EPS, p = 0.11; and IPS = 0.96). Greater enamel %SHL was also found for the sucrose group (p < 0.05) but the demineralization did not increase during starvation (p = 0.09). In conclusion, the findings suggest that EPS metabolization by S. mutans during night starvation do not contribute to increase enamel demineralization occurred during the daily abundance of sugar.

The history of public health use of fluorides in caries prevention

AIM

The aim of our study was to chronologically analyse various public health measures of fluoride use in caries prevention.

METHODS

We systematically searched the PubMed database on the preventive role of fluorides in public health, published from 1984 to 2014. The search process was divided into four steps, where inclusion and exclusion criteria were defined. Qualitative methodology was used for the article analysis. In the research process, the described forms of F use, diversity of the described F agents, and the observed population group were analysed.

RESULTS

In our systematic review, 40 relevant reviews were revealed. Fluorides have been used in many different forms, but only a few studies showed their significant role in public health. Water fluoridation was the most important public health measure. In the recent decades, the number of studies on topical fluorides is constantly rising. The most extensively described topical forms of fluorides are professionally applied fluoride agents and fluoride toothpaste for home-use. The use of fluoride containing toothpaste in caries prevention is a safe and successful public health measure (PHM) if their use is widespread, and it is recommended for all. The results on other topical forms of fluorides are insufficient to be suggested as an important PHM.

CONCLUSIONS

The role of fluorides in public health prevention has changed in accordance with the knowledge about the fluoride cariostatic mechanism. Previously the most important pre-eruptive effect of fluorides was supplemented by the post eruptive effect. Abundant evidence exists to show the effectiveness of systemic and topical fluorides.

Relationship among α amylase and carbonic anhydrase VI in saliva, visible biofilm, and early childhood caries: a longitudinal study

AIM

This longitudinal study investigated the relationship among early childhood caries (ECC), α amylase, carbonic anhydrase VI (CA VI), and the presence of visible biofilm, besides detecting if these variables could predict risk for ECC.

DESIGN

One hundred children were divided into two groups: caries group (n = 45) and caries-free group (n = 55). Visible biofilm on maxillary incisors was recorded, followed by caries diagnosis in preschoolers at baseline and at follow-up. Saliva samples were collected, and activities of CA VI and α amylase were determined. Data normality was assessed by Shapiro-Wilk test and then Mann-Whitney, Spearman correlation, and chi-square tests followed by multiple logistic regression analysis (α = 0.05, 95% confidence interval).

RESULTS

CA VI activity was significantly higher in saliva of children with caries (P ≤ 0.05), and α amylase activity was significantly higher in saliva of caries-free children (P < 0.0001). Children with α amylase activity in saliva lower than 122.8 U/mL (OR = 3.33 P = 0.042) and visible biofilm on maxillary incisors (OR = 3.6 P = 0.009) were more likely to develop ECC than caries-free children. A negative correlation between caries and α amylase activity was found (P = 0.0008).

CONCLUSIONS

The presence of visible biofilm and low salivary activity of α amylase may be considered risk predictors for ECC.

Health-Associated Niche Inhabitants as Oral Probiotics: The Case of Streptococcus dentisani

Oral diseases, including dental caries and periodontitis, are among the most prevalent diseases worldwide and develop as a consequence of a microbial dysbiosis. Several bacterial strains are being tested as potential oral health-promoting organisms, but usually they are species isolated from niches other than the site where they must exert its probiotic action, typically from fecal samples. We hypothesize that oral inhabitants associated to health conditions will be more effective than traditional, gut-associated probiotic species in key aspects such as colonization of the oral site where disease takes place or the possession of oral health promoting functions, as well as more practical issues like safety and toxicity, and establishing proper doses for administration. As an example of these active colonizers, we describe the case of Streptococcus dentisani, a new streptococcal species isolated from dental plaque of caries-free individuals. We have detected it in 98% of dental plaque samples from healthy individuals and, as expected, it does not produce any toxic secondary metabolite and does not survive a simulated stomach digestion, preventing potential secondary effects. Besides, this species has a double probiotic action, as it inhibits the growth of major oral pathogens through the production of bacteriocins, and also buffers acidic pH (the primary cause of dental caries) through an arginolytic pathway. We propose the use of S. dentisani as a promising probiotic against tooth decay.

Effect of Herbal and Fluoride Mouth Rinses on Streptococcus mutans and Dental Caries among 12-15-Year-Old School Children: A Randomized Controlled Trial

To assess and compare the effect of herbal and fluoride mouth rinses on Streptococcus mutans count and glucan synthesis by Streptococcus mutans and dental caries, a parallel group placebo controlled randomized trial was conducted among 240 schoolchildren (12–15 years old). Participants were randomly divided and allocated into Group I (0.2% fluoride group), Group II (herbal group), and Group III (placebo group). All received 10 ml of respective mouth rinses every fortnight for a period of one year. Intergroup and intragroup comparison were done for Streptococcus mutans count and glucan synthesis by Streptococcus mutans and dental caries. Streptococcus mutans count showed a statistically significant difference between Group I and Group III (p = 0.035) and also between Group II and Group III (p = 0.039). Glucan concentration levels showed a statistically significant difference (p = 0.024) between Group II and Group III at 12th month. Mean DMF scores showed no statistical difference between the three groups (p = 0.139). No difference in the level of significance was seen in the intention-to-treat and per-protocol analysis. The present study showed that both herbal and fluoride mouth rinses, when used fortnightly, were equally effective and could be recommended for use in school-based health education program to control dental caries. Trial registration number is CTRI/2015/08/006070.

Cariogenic Potential of Sucrose Associated with Maltodextrin on Dental Enamel

Maltodextrin is a hydrolysate of cornstarch and has been widely used in the food industry associated with sucrose. The addition of starch can increase the cariogenic potential of sucrose; however, there are sparse data regarding the cariogenicity of sucrose associated with maltodextrin. Therefore, the aim of this study was to test in situ if maltodextrin could increase the cariogenic potential of sucrose. This was an in situ, randomized, crossover, split-mouth, and double-blind study. Volunteers wore palatal appliances containing bovine enamel blocks for 2 periods of 14 days. They dripped the following solutions on the enamel blocks 8 times per day: deionized distilled water (DDW), maltodextrin (M), sucrose + maltodextrin (S+M), or sucrose (S). At the end of each experimental period, biofilms were collected and analyzed for microbiological (mutans streptococci, lactobacilli, and total microorganisms counts) and biochemical (calcium, inorganic phosphate, fluoride, and insoluble extracellular polysaccharides concentrations) compositions. The enamel demineralization was assessed by microhardness. Treatments S and S+M resulted in a lower inorganic composition and higher concentration of insoluble extracellular polysaccharides in the biofilms, and higher enamel mineral loss compared to DDW and M. It can be concluded that the cariogenic potential of sucrose is not changed when this carbohydrate is associated with maltodextrin (dextrose equivalent 13-17).

Impact of malocclusion and dentofacial anomalies on the prevalence and severity of dental caries among adolescents

OBJECTIVES

To investigate the association between malocclusion/dentofacial anomalies and dental caries among adolescents.

MATERIALS AND METHODS

A cross-sectional study was conducted with 509 adolescents aged 11 to 14 years enrolled at public schools in the city of Osório in southern Brazil. Parents/caregivers answered a structured questionnaire on demographic and socioeconomic variables. A trained examiner recorded the presence of malocclusion (Dental Aesthetic Index [DAI]), traumatic dental injury, and dental caries. Data analysis involved the chi-square, Mann-Whitney, and Kruskal-Wallis tests. Poisson regression with robust variance was used for the multivariable analysis.

RESULTS

A total of 44.8% of the adolescents had dental caries (mean DFMT  =  1.33 ± 1.84). The DAI index ranged from 15 to 77 (mean  =  29.0 ± 7.9); 43.6% of the sample had severe malocclusion and 11.6% had traumatic dental injury. The prevalence and severity of dental caries were significantly greater among adolescents with severe malocclusion. The multivariate analysis demonstrated that adolescents with severe or handicapping malocclusion had a 31% greater probability of having dental caries (prevalence ratio: 1.31; 95% CI: 1.02-1.67), independently of demographic, socioeconomic, or clinical aspects. The orthodontic characteristics associated with the occurrence and severity of caries were maxillary irregularity ≥3 mm (P  =  .021) and abnormal molar relationship (P  =  .021).

CONCLUSIONS

Handicapping malocclusion, maxillary irregularity, and abnormal molar relationship were associated with the occurrence and severity of dental caries. The findings suggest that the prevention and treatment of these conditions can contribute to a reduction in dental caries among adolescents.

Evaluation of Microhardness of Residual Dentin in Primary Molars Following Caries Removal with Conventional and Chemomechanical Techniques: An In vitro Study

Background:

Many patients consider removal of caries to be a very unpleasant experience. Removal of caries with conventional drill is considered traumatic mainly due to fear and anxiety of children and their parents. Minimally invasive dentistry adopts a philosophy that integrates prevention, remineralization, and minimal intervention for the placement and replacement of restorations, thus reaching the treatment objective using the least invasive surgical approach, with the removal of the minimal amount of healthy tissues. Chemomechanical caries removal (CMCR) is a method for minimally invasive, gentle dentin caries removal based on biological principles which is an effective alternative to the traditional method. The present study was done to compare the microhardness of sound dentin before and after carious removal using a chemomechanical method and a conventional method.

Materials and Methods:

The present in vitro study was done on 28 proximal surfaces of fourteen extracted primary molars (with active caries on one proximal surface and sound side as control). The study was done to assess the Knoop microhardness of remaining dentinal surface after caries removal using a slow speed conventional bur and a chemomechanical method (Carie-Care^™). Results and

Conclusion:

The rotary instrument group showed a consistent microhardness value with not much difference according to depth. The chemomechanical group showed a lesser microhardness value closer to the cavity floor than away from it. The microhardness values at all depths were significantly different for each treatment group with an increased value seen in the rotary group. The mean microhardness values of residual dentin in treated side were found to be insignificant when compared among each interval in each group. The microhardness of sound dentin had high significant difference from that of residual dentin in both the rotary group and the chemomechanical group.

Prevalence of Candida albicans and carriage of Candida non-albicans in the saliva of preschool children, according to their caries status

OBJECTIVE

This study was conducted to establish associations among the Candida carriage rate, the diversity of Candida species carried and the different caries status of preschool children.

MATERIALS AND METHODS

Sixty-one children between 2 and 5 years of age were examined by a single expert examiner and were divided into three groups, the caries-free, moderate caries and severe caries groups, according to the criteria of the International Caries Detection and Assessment System II (ICDAS). Saliva samples were obtained from the members of each group and were plated on Sabouraud agar plates to assess the Candida carriage rates. CHROMagar Candida medium was used for the preliminary screening. Biochemical testing or PCR/sequencing was conducted to identify the different Candida species in the samples. The differences observed were considered significant if the p value was <0.05.

RESULTS

The Candida carriage rate and the number of species of this fungus carried were higher in the group with the highest level of caries severity (p < 0.05). Whereas Candida albicans was the most predominant Candida species in the saliva of all of the children, C. dubliniensis was identified only in the most caries-affected group in addition to other rare species of Candida non-albicans.

CONCLUSIONS

A high salivary Candida carriage rate and the presence of specific species of this fungus (such as C. albicans and C. dubliniensis) appear to be related to the severity of caries experienced by preschool children.

Effect of Lippia alba and Cymbopogon citratus essential oils on biofilms of Streptococcus mutans and cytotoxicity in CHO cells

BACKGROUND

Caries is a public health problem, given that it prevails in 60 to 90% of the school-age global population. Multiple factors interact in its etiology, among them dental plaque is necessary to have lactic acid producing microorganisms like Streptococcus from he Mutans group. Existing prevention and treatment measures are not totally effective and generate adverse effects, which is why it is necessary to search for complementary strategies for their management.

AIM

The study sought to evaluate the eradication capacity of Streptococcus mutans biofilms and the toxicity on eukaryotic cells of Lippia alba and Cymbopogon citratus essential oils.

METHODOLOGY

Essential oils were extracted from plant material through steam distillation and then its chemical composition was determined. The MBEC-high-throughput (MBEC-HTP) (Innovotech, Edmonton, Alberta, Canada) assay used to determine the eradication concentration of S. mutans ATCC 35668 strain biofilms. Cytotoxicity was evaluated on CHO cells through the MTT cell proliferation assay.

RESULTS

The major components in both oils were Geraniol and Citral; in L. alba 18.9% and 15.9%, respectively, and in C. citratus 31.3% and 26.7%. The L. alba essential oils presented eradication activity against S. mutans biofilms of 95.8% in 0.01mg/dL concentration and C. citratus essential oils showed said eradication activity of 95.4% at 0.1, 0.01mg/dL concentrations and of 93.1% in the 0.001mg/dL concentration; none of the concentrations of both essential oils showed toxicity on CHO cells during 24h.

CONCLUSION

The L. alba and C. citratus essential oils showed eradication activity against S. mutans biofilms and null cytotoxicity, evidencing the need to conduct further studies that can identify their active components and in order to guide a safe use in treating and preventing dental caries.

Enamel and dentine demineralization by a combination of starch and sucrose in a biofilm - caries model

Sucrose is the most cariogenic dietary carbohydrate and starch is considered non-cariogenic for enamel and moderately cariogenic for dentine. However, the cariogenicity of the combination of starch and sucrose remains unclear. The aim of this study was to evaluate the effect of this combination on Streptococcus mutans biofilm composition and enamel and dentine demineralization. Biofilms of S. mutans UA159 were grown on saliva-coated enamel and dentine slabs in culture medium containing 10% saliva. They were exposed (8 times/day) to one of the following treatments: 0.9% NaCl (negative control), 1% starch, 10% sucrose, or 1% starch and 10% sucrose (starch + sucrose). To simulate the effect of human salivary amylase on the starch metabolization, the biofilms were pretreated with saliva before each treatment and saliva was also added to the culture medium. Acidogenicity of the biofilm was estimated by evaluating (2 times/day) the culture medium pH. After 4 (dentine) or 5 (enamel) days of growth, biofilms (n = 9) were individually collected, and the biomass, viable microorganism count, and polysaccharide content were quantified. Dentine and enamel demineralization was assessed by determining the percentage of surface hardness loss. Biofilms exposed to starch + sucrose were more acidogenic and caused higher demineralization (p < 0.0001) on either enamel or dentine than those exposed to each carbohydrate alone. The findings suggest that starch increases the cariogenic potential of sucrose.

Bio-Photonic Detection and Quantitative Evaluation Method for the Progression of Dental Caries Using Optical Frequency-Domain Imaging Method

The initial detection of dental caries is an essential biomedical requirement to barricade the progression of caries and tooth demineralization. The objective of this study is to introduce an optical frequency-domain imaging technique based quantitative evaluation method to calculate the volume and thickness of enamel residual, and a quantification method was developed to evaluate the total intensity fluctuation in depth direction owing to carious lesions, which can be favorable to identify the progression of dental caries in advance. The cross-sectional images of the ex vivo tooth samples were acquired using 1.3 μm spectral domain optical coherence tomography system (SD-OCT). Moreover, the advantages of the proposed method over the conventional dental inspection methods were compared to highlight the potential capability of OCT. As a consequence, the threshold parameters obtained through the developed method can be used as an efficient investigating technique for the initial detection of demineralization.

Synthesis of Ag doped calcium phosphate particles and their antibacterial effect as additives in dental glass ionomer cements

Developing dental restorations with enhanced antibacterial properties has been a constant quest for materials scientists. The aim of this study was to synthesize silver doped calcium phosphate particles and use them to improve antibacterial properties of conventional glass ionomer cement. The Ag doped monetite (Ag-DCPA) and hydroxyapatite (Ag-HA) were synthesized by precipitation method and characterized using X-ray diffraction, scanning electron microscope and X-ray fluorescence spectroscopy. The antibacterial properties of the cements aged for 1 day and 7 days were evaluated by direct contact measurement using staphylococcus epidermis Xen 43. Ion concentrations (F^- and Ag⁺) and pH were measured to correlate to the results of the antibacterial study. The compressive strength of the cements was evaluated with a crosshead speed of 1 mm/min. The glass ionomer cements containing silver doped hydroxyapatite or monetite showed improved antibacterial properties. Addition of silver doped hydroxyapatite or monetite did not change the pH and ion release of F^-. Concentration of Ag⁺ was under the detection limit (0.001 mg/L) for all samples. Silver doped hydroxyapatite or monetite had no effect on the compressive strength of glass ionomer cement.

Relationship between body mass index and dental caries in children, and the influence of socio-economic status

OBJECTIVES

To determine the association of body mass index (BMI) with dental caries in Indian schoolchildren, and to analyse the influence of socio-economic status (SES).

METHODS

The study population consisted of 11- to 14-year-old children from Medak District in Telangana State, India. The Indian Academy of Paediatrics 2015 growth charts were used to categorise children as underweight, overweight, normal or obese, based on their BMI. Data on the SES of the family were collected through questionnaires. Clinical examination for dental caries was performed by a single examiner.

RESULTS

A total of 1,092 subjects returned questionnaires and were clinically examined (giving a response rate of 85%). There were no significant differences in caries prevalence and experience across the categories of BMI. However, caries prevalence and experience in overweight children were 24.8% and 0.69 ± 1.51, respectively, while the corresponding values in normal-weight children were 35% and 0.85 ± 1.50, respectively. Among children of high-SES families, overweight children had approximately 71% fewer caries than did those who were normal weight [incidence rate ratio (IRR) = 0.29; 95% CI: 0.11-0.78)].

CONCLUSIONS

BMI was not associated with dental caries prevalence and experience in this population. The association of BMI with dental caries varied across SES categories. In the high-SES category, overweight children experienced fewer caries than did normal-weight children.

Effect of Fluoride Concentration on Reduction of Enamel Demineralization According to the Cariogenic Challenge

Abstract Fluoride present in toothpaste at 1,100 µg/g is considered effective on caries control. However, under high cariogenic challenge due to increasing sugar exposure, higher fluoride concentration (5,000 µg/g) could be necessary to compensate the unbalance on caries process. This was tested in a pH-cycling regimen, which evaluated the effect of fluoride concentration relative to toothpaste on reduction of enamel demineralization under conditions of two levels of cariogenic challenge. Enamel slabs (n=20) were subjected to two pH-cycling regimens, simulating 8x and 16x/day sugar exposure and were treated with solutions containing: 0 (no fluoride), 275 or 1,250 µg F/mL, resulting in 6 treatment groups: 4-h/0-F; 8-h/0-F; 4-h/275-F; 8-h/275-F; 4-h/1,250-F and 8-h/1,250-F. The 275 and 1,250 µg F/mL concentrations simulate mouth salivary dilution when 1,100 and 5,000 µg/g toothpastes are used. Enamel demineralization was assessed by surface (%SHL) and cross-sectional hardness. Fluoride taken up by enamel was also evaluated. Data were analyzed by ANOVA one-way and Tukey's test. The treatment with 1,250 µg F/mL significantly reduced %SHL compared with 275 µg F/mL (p<0.05), irrespective the level of cariogenic challenge (4-h/1,250-F vs. 4-h/275-F and 8-h/1,250-F vs 8-h/275-F comparisons, respectively). These data were supported by fluoride concentration found in enamel. These findings suggest that higher fluoride concentrations could partly compensate the greater caries risk under higher cariogenic challenge due to increasing sugar exposure.

Frequency of sucrose exposure on the cariogenicity of a biofilm-caries model

OBJECTIVE

Although sucrose is considered the most cariogenic carbohydrate in the human diet, the question of how many exposures are needed to induce damage on the hard dental tissues remains unclear. To approach this question, different frequencies of daily sucrose exposure were tested on a relevant biological caries model.

MATERIALS AND METHODS

Biofilms of the Streptococcus mutans were formed on enamel slabs and exposed to cariogenic challenges with 10% sucrose for 5 min at 0, 1, 3, 5, 8, or 10 times per day. After 5 days, biofilms were retrieved to analyze biomass, protein content, viable bacteria, and polysaccharide formation. Enamel demineralization was evaluated by percentage of microhardness loss (percentage surface hardness loss [%SHL]).

RESULTS

Biomass, protein content, polysaccharide production, acidogenicity of the biofilm, and %SHL proportionally increased with the number of daily exposures to sucrose (P < 0.05). One daily sucrose exposure was enough to induce 20% more demineralization than the negative unexposed control. Higher frequencies induced greater demineralization and more virulent biofilms, but eight and ten exposures were not different between them in most of the analyzed variables (P > 0.05).

CONCLUSIONS

Higher sucrose exposure seems to increase cariogenicity, in a frequency-dependent manner, by the modification of bacterial virulent properties.

Oral health-related knowledge, attitudes and habits in relation to perceived oral symptoms among 12-year-old school children

Objective The aim of the study was to investigate oral health-related knowledge, attitudes and habits and their relationship to perceived oral symptoms among 12-year-olds and differences between boys and girls. Material and methods The study population consisted of children (n = 588) in 15 randomly selected elementary schools in Turku, Finland. Associations between oral health-related habits, knowledge and attitudes with perceived oral symptoms and gender differences were evaluated with χ(2)-test, Mann-Whitney U-test and logistic regression analysis. Results Oral health promoting habits but not knowledge or attitudes associated significantly with absence of oral symptoms. Girls reported a higher percentage of several health promotional habits than boys. Girls reported more frequently gingival bleeding and less frequently dental calculus than boys did. The most common oral symptom was gingival bleeding. Conclusions The present findings suggest some gender-related differences in oral health habits, attitudes, as well as perceived oral symptoms in 12-year-olds. There seems, however, not to be gender differences in relation to knowledge or the association of health habits with perceived oral symptoms. It is important to maintain health promotion at schools and additional efforts should be aimed at translating knowledge into action.

Association between oral health habits and dental caries among children in Pyongyang, Democratic People's Republic of Korea

AIM

To evaluate the self-reported oral health habits and their association with the occurrence of dental caries among children in Pyongyang, Democratic People's Republic of Korea (DPRK), after 6 years of activities under the auspices of the Children's Oral Health Promotion Programme (COHPP).

METHODS

The data were collected in September 2013 in two of the most central districts of Pyongyang City, DPRK. The sample consisted of 492 children aged 10 and 13 years who had participated in the COHPP for 6 years. The children filled in a self-completed, structured questionnaire on oral health habits and were examined clinically by a dentist. The differences in mean (SD) number of decayed primary (dt) and permanent teeth (DT) and their sum (dt + DT) subdivided according to genders, age groups, districts and self-reported oral health habits were evaluated using Mann-Whitney U-test. The associations between self-reported oral health habits and the occurrence of dental caries were evaluated with chi-square test and logistic regression analyses.

RESULTS

The school-aged children commonly reported healthy oral hygiene habits but sweet snacks were commonly used. The occurrence of dental caries associated statistically significantly with the frequency of sweet snacking (p=0.011) but not with the frequency of tooth brushing (p=0.725) or the use of water for thirst instead of sugary beverages (p=0.189).

CONCLUSION

A more effective promotion of healthy dietary habits with innovative approaches and close collaboration with different social actors will be needed in future.

Influence of the Culture Medium in Dose-Response Effect of the Chlorhexidine on Streptococcus mutans Biofilms

The aim of this study was to evaluate the influence of culture medium on dose-response effect of chlorhexidine (CHX) on Streptococcus mutans UA159 biofilm and validate the use of the cation-adjusted-Müller-Hinton broth (MH) for the evaluation of antibacterial activity. Ultrafiltered Tryptone-Yeast Extract Broth (UTYEB) was compared against MH and MH with blood supplementation (MHS). For each medium, six groups (n = 4) were assessed: two negative control groups (baseline 48 and 120 h) and four experimental groups (0.0001, 0.001, 0.012, and 0.12% CHX). S. mutans biofilm grew on glass slides of each media containing 1% sucrose. After 48 h of growth, biofilms of baseline 48 h were collected and the other groups were treated for 1 min, twice a day, for 3 days, with their respective treatments. The media were changed daily and pH was measured. After 120 h, biofilms were collected and dry weight and viable microorganisms were determined. Results showed CHX dose-response effect being observed in all media for all the variables. However, MH and MHS showed higher sensitivity than UTYEB (p < 0.05). We can conclude that the culture medium does influence dose-response effect of CHX on Streptococcus mutans biofilm and that MH can be used for antibacterial activity.

A Predictive Model for Root Caries Incidence

This study aimed to find the set of risk indicators best able to predict root caries (RC) incidence in caries-active adults utilizing data from the Xylitol for Adult Caries Trial (X-ACT). Five logistic regression models were compared with respect to their predictive performance for incident RC using data from placebo-control participants with exposed root surfaces at baseline and from two study centers with ancillary data collection (n = 155). Prediction performance was assessed from baseline variables and after including ancillary variables [smoking, diet, use of removable partial dentures (RPD), toothbrush use, income, education, and dental insurance]. A sensitivity analysis added treatment to the models for both the control and treatment participants (n = 301) to predict RC for the control participants. Forty-nine percent of the control participants had incident RC. The model including the number of follow-up years at risk, the number of root surfaces at risk, RC index, gender, race, age, and smoking resulted in the best prediction performance, having the highest AUC and lowest Brier score. The sensitivity analysis supported the primary analysis and gave slightly better performance summary measures. The set of risk indicators best able to predict RC incidence included an increased number of root surfaces at risk and increased RC index at baseline, followed by white race and nonsmoking, which were strong nonsignificant predictors. Gender, age, and increased number of follow-up years at risk, while included in the model, were also not statistically significant. The inclusion of health, diet, RPD use, toothbrush use, income, education, and dental insurance variables did not improve the prediction performance.

Comparison of two preventive interventions on dental caries among children in Democratic People's Republic of Korea

OBJECTIVES

The aim was to compare the change in dental caries status in two different intervention groups of the Children's Oral Health Promotion Programme (COHPP).

METHODS

A longitudinal study among 500 children who had participated into the COHPP for 6 years was conducted in Pyongyang, Democratic People's Republic of Korea (DPRK). Children in Group I received intensified school-based intervention and were clinically examined at the age of 7 years in 2007 (n = 250), 10 years in 2010 (n = 250) and 13 years in 2013 (n = 242). Children in Group II (n = 250) joined the programme at the age of 4 years in kindergarten in 2007, were provided with early preschool-based intervention and were clinically examined at the age of 7 years in 2010 and 10 years in 2013.

RESULTS

Both the prevalence and the mean number of dt + DT decreased significantly in both groups during the follow-up. This was due to decrease in the number of dt, whereas the number of DT remained relatively constant. Poisson regression showed that the association between the group status and the change in the number of dt + DT was statistically significant when adjusted for gender but disappeared when the school was included in the analysis.

CONCLUSIONS

The decrease in dental caries may be partly due to the exfoliation of deciduous teeth and dental treatment received. However, the study gave some reference emphasizing the early starting of the prevention.

Bioactive glass fillers reduce bacterial penetration into marginal gaps for composite restorations

OBJECTIVE

Bioactive glass (BAG) is known to possess antimicrobial and remineralizing properties; however, the use of BAG as a filler for resin based composite restorations to slow recurrent caries has not been studied. Accordingly, the objective of this study was to investigate the effect of adding 15wt% BAG to a resin composite on bacterial biofilms penetrating into marginal gaps of simulated tooth fillings in vitro during cyclic mechanical loading.

METHODS

Human molars were machined into approximately 3mm thick disks of dentin and 1.5-2mm deep composite restorations were placed. A narrow 15-20 micrometer wide dentin-composite gap was allowed to form along half of the margin by not applying dental adhesive to that region. Two different 72wt% filled composites were used, one with 15wt% BAG filler (15BAG) and the balance silanated strontium glass and one filled with aerosol silica and silanated strontium glass without BAG (0BAG-control). Samples of both groups had Streptococcus mutans biofilms grown on the surface and were tested inside a bioreactor for two weeks while subjected to periods of cyclic mechanical loading. After post-test biofilm viability was confirmed, each specimen was fixed in glutaraldehyde, gram positive stained, mounted in resin and cross-sectioned to reveal the gap profile. Depth of biofilm penetration for 0BAG and 15BAG was quantified as the fraction of gap depth. The data were compared using a Student's t-test.

RESULTS

The average depth of bacterial penetration into the marginal gap for the 15BAG samples was significantly smaller (∼61%) in comparison to 0BAG, where 100% penetration was observed for all samples with the biofilm penetrating underneath of the restoration in some cases.

SIGNIFICANCE

BAG containing resin dental composites reduce biofilm penetration into marginal gaps of simulated tooth restorations. This suggests BAG containing composites may have the potential to slow the development and propagation of secondary tooth decay at restoration margins.

Inhibition of Streptococcus mutans biofilm formation, extracellular polysaccharide production, and virulence by an oxazole derivative

Dental caries, a biofilm-related oral disease, is a result of disruption of the microbial ecological balance in the oral environment. Streptococcus mutans, which is one of the primary cariogenic bacteria, produces glucosyltransferases (Gtfs) that synthesize extracellular polysaccharides (EPSs). The EPSs, especially water-insoluble glucans, contribute to the formation of dental plaque, biofilm stability, and structural integrity, by allowing bacteria to adhere to tooth surfaces and supplying the bacteria with protection against noxious stimuli and other environmental attacks. The identification of novel alternatives that selectively inhibit cariogenic organisms without suppressing oral microbial residents is required. The goal of the current study is to investigate the influence of an oxazole derivative on S. mutans biofilm formation and the development of dental caries in rats, given that oxazole and its derivatives often exhibit extensive and pharmacologically important biological activities. Our data shows that one particular oxazole derivative, named 5H6, inhibited the formation of S. mutans biofilms and prevented synthesis of extracellular polysaccharides by antagonizing Gtfs in vitro, without affecting the growth of the bacteria. In addition, topical applications with the inhibitor resulted in diminished incidence and severity of both smooth and sulcal surface caries in vivo with a lower percentage of S. mutans in the animals' dental plaque compared to the control group (P < 0.05). Our results showed that this oxazole derivative has the capacity to inhibit biofilm formation and cariogenicity of S. mutans.

Pyrosequencing of Plaque Microflora In Twin Children with Discordant Caries Phenotypes

Despite recent successes in the control of dental caries, the mechanism of caries development remains unclear. To investigate the causes of dental decay, especially in early childhood caries, the supragingival microflora composition of 20 twins with discordant caries phenotypes were analyzed using high-throughput pyrosequencing. In addition, the parents completed a lifestyle questionnaire. A total of 228,789 sequencing reads revealed 10 phyla, 84 genera, and 155 species of microflora, the relative abundances of these strains varied dramatically among the children, Comparative analysis between groups revealed that Veillonella, Corynebacterium and Actinomyces were presumed to be caries-related genera, Fusobacterium, Kingella and Leptotrichia were presumed to be healthy-related genus, yet this six genera were not statistically significant (P>0.05). Moreover, a cluster analysis revealed that the microbial composition of samples in the same group was often dissimilar but that the microbial composition observed in twins was usually similar. Although the genetic and environmental factors that strongly influence the microbial composition of dental caries remains unknown, we speculate that genetic factors primarily influence the individual's susceptibility to dental caries and that environmental factors primarily regulate the microbial composition of the dental plaque and the progression to caries. By using improved twins models and increased sample sizes, our study can be extended to analyze the specific genetic and environmental factors that affect the development of caries.

Effect on oral pH changes and taste perception in 10-14-year-old children, after calcium fortification of a fruit juice

AIM

The aim was to determine the effect of calcium fortification of a commercially available mixed-fruit juice on oral pH changes and taste perception in a group of 10 to 14 year-old Indian children.

METHOD

A controlled, blinded, non-randomised clinical trial was adopted, consisting of a sample of 100 healthy children (DMFT <3; age 10-14 years), who were exposed to three test juices one by one [Group A: original fruit juice (control group); Group B: calcium-fortified fruit juice and Group C: calcium + vitamin D fortified fruit juice]. Oral pH, collection of saliva and plaque sampling was undertaken, before and after the juice exposure by each subject at 0, 1, 5, 15, 30 and 45 min. The respective pH was measured with a digital pH meter. For taste perception, a scoring system was used after exposure of the juices to the subjects in a blind manner. The statistical evaluation was done using one-way ANOVA for salivary and plaque pH and Kruskal-Wallis test for buffer capacity and taste perception.

RESULTS

There was a smaller drop in salivary and plaque pH (p < 0.5) and a significant reduction in perceived taste (p < 0.001) by the subjects after calcium modification of fruit juice.

CONCLUSION

The calcium-modified mixed fruit juices was less acidogenic compared with the unfortified juice, and hence will be less cariogenic and erosive towards teeth.

Oral health in prehistoric San Pedro de Atacama oases, Northern Chile

After almost 2000 years of local development, including limited trading with neighboring ethnic groups, the societies that occupied the oases of San Pedro de Atacama, Northern Chile, became part of the trade web of the Tiwanaku empire, between 500 and 1000 CE. Archaeological evidence tends to support the idea that the period under the influence of the altiplano (high plane) empire was very affluent. Here we investigate the possibility that this affluence had a positive impact on the health status of the Atacameneans, using the oral health as an indirect indicator of quality of life. Dental decay, dental abscess, dental wear, linear enamel hypoplasia, periodontal disease and dental calculus were analyzed on 371 skeletons from 12 sites from San Pedro de Atacama oases. We believe that if, indeed, there were better biological conditions during the altiplano influence, this could have been caused by the access to a more diversified food intake promoted by the intensification of the trading network established by Tiwanaku in the central-south Andes, of which San Pedro de Atacama became an important node.

Fluoride varnishes with calcium glycerophosphate: fluoride release and effect on in vitro enamel demineralization

The aims of this study were (1) to assess the amount of fluoride (F) released from varnishes containing calcium glycerophosphate (CaGP) and (2) to assess the effect of the experimental varnishes on in vitro demineralization. Six test groups using 5 varnishes: base varnish (no active ingredients); Duraphat® (2.26% NaF); Duofluorid® (5.63% NaF/CaF2); experimental varnish 1 (1% CaGP/5.63% NaF/CaF2); experimental varnish 2 (5% CaGP/5.63% NaF/CaF2); and no varnish were set up. In stage 1, 60 acrylic blocks were randomly distributed into 6 groups (n = 10). Then 300 µg of each varnish was applied to each block. The blocks were immersed in deionized water, which was changed after 1, 8, 12, 24, 48 and 72 hours. Fluoride concentration in the water was analyzed using a fluoride electrode. In stage 2, 60 bovine enamel samples were distributed into 6 groups (n = 10), and treated with 300 µg of the respective varnish. After 6 h the varnish was removed and the samples were subjected to a 7-day in vitro pH cycle (6 h demineralization/18 h remineralization per day). The demineralization was measured using surface hardness. The results showed that both experimental varnishes released more fluoride than Duofluorid® and Duraphat® (p < 0.05), but Duraphat® showed the best preventive effect by decreasing enamel hardness loss (p < 0.05). Therefore, we conclude that even though (1) the experimental varnishes containing CaGP released greater amounts of F, (2) they did not increase in the preventive effect against enamel demineralization.

The association of depression and anxiety with dental caries and periodontal disease among Finnish adults

OBJECTIVE

To explore the association of depression and anxiety with two oral health outcomes, dental caries and periodontal disease and assess possible mediators for any of the associations.

METHODS

Secondary analysis of the Finnish Health 2000 Survey. Depression was assessed with Beck's Depression Inventory and anxiety with Composite International Diagnostic Interview. Number of decayed teeth included carious lesions reaching dentine; periodontal disease was number of teeth with periodontal pockets of 4 mm or deeper. Third molars were excluded. The association of mental disorders and oral health was tested in regression models adjusted for confounders and potential mediators.

RESULTS

Depression was associated with number of decayed teeth only among 35- to 54-year-olds. The association between anxiety and the number of decayed teeth was not statistically significant. Depression and periodontal pocketing were not significantly associated.

CONCLUSION

Depression was significantly associated with number of decayed teeth only among participants aged 35-54 old and not with other age groups. Neither depression nor anxiety was significantly related to periodontal disease.

Maternal Dental Anxiety and its Effect on Caries Experience Among Children in Udaipur, India

CONTEXT

Dental caries is a common oral disease among children. There are various factors that influence caries development. Parents and family environment influence oral health behaviours among children. Dental Anxiety is a common hindrance in seeking dental treatment. Mothers' dental anxiety may act as a barrier to seek professional advice about their children's caries experience.

AIM

To evaluate dental anxiety among mothers and its possible relationship with caries experience in their children in Udaipur city, India.

SETTING AND DESIGN

The sample was selected from those attending Darshan Dental College and Hospital, Udaipur for dental treatment. The study period was from June 2014 to November 2014.

MATERIALS AND METHODS

A cross-sectional survey was designed. A total of 187 mother-child pairs were recruited for the study. The children's age ranged from 3-14 years. Modified Dental Anxiety Scale (MDAS), Hindi version, was used to evaluate dental anxiety among the mothers that categorizes the dental anxiety into five levels. Demographic detail such as age, educational level, and family income was also collected. The World Health Organization (WHO) criteria was utilized for the diagnosis of dental caries in children. DMFT (Decayed, missing and filled teeth) and DMFS (Decayed, missing and filled surfaces) scores were then calculated.

STATISTICAL ANALYSIS

Statistical Package for Social Sciences (SPSS) version 20.0 was used to interpret data. Maternal anxiety scores taken as mean MDAS were compared with various independent variables. Statistical tests were used to compare maternal anxiety and children's caries experience. A p value equal or less than 0.05 was considered as statistically significant.

RESULTS

Almost half (49.7%) of the mothers reported as being 'fairly anxious' or 'very anxious'. There was a significant (p=.001) difference in maternal dental anxiety level in relation to age of the children. Mothers of younger children reported higher anxiety scores. Similarly, mothers with lesser education and lesser family income reported higher anxiety scores. The mean decayed score in children of very anxious mothers and phobic mothers was significantly (p=.001) higher as compared to the children of the mothers with lower anxiety levels.

CONCLUSION

There was a strong positive association between maternal dental anxiety and children's dental caries experience.

The development and validation of a new technology, based upon 1.5% arginine, an insoluble calcium compound and fluoride, for everyday use in the prevention and treatment of dental caries

OBJECTIVE

This paper briefly discusses caries prevalence, the multi-factorial nature of caries etiology, caries risk and the role and efficacy of fluoride. The paper also highlights research on bacterial metabolism which provided understanding of the mouth's natural defenses against caries and the basis for the development of a new technology for the everyday prevention and treatment of caries. Finally, evidence that the technology complements and enhances the anti-caries efficacy of fluoride toothpaste is summarized.

CONCLUSIONS

Global data show that dental caries is a prevalent disease, despite the successful introduction of fluoride. Caries experience depends on the balance between consumption of sugars and oral hygiene and the use of fluoride. Three scientific concepts are fundamental to new measures to detect, treat and monitor caries: (1) dental caries is a dynamic process, (2) dental caries is a continuum of stages from reversible, pre-clinical to irreversible, clinically detectable lesions, and (3) the caries process is a balance of pathological and protective factors that can be modulated to manage caries. Fluoride functions as a protective factor by arresting and reversing the caries process, but fluoride does not prevent pathological factors that initiate the process. A novel technology, based upon arginine and an insoluble calcium compound, has been identified which targets dental plaque to prevent initiation of the caries process by reducing pathological factors. As the mechanisms of action of arginine and fluoride are highly complementary, a new dentifrice, which combines arginine with fluoride, has been developed and clinically proven to provide superior caries prevention.

A 4-year assessment of a new water-fluoridation scheme in New South Wales, Australia

OBJECTIVE

To monitor the changes in dental caries prevalence of 5- to 7-year-old children living in a fluoridated area, a newly fluoridated area and in an area without water fluoridation, in NSW, Australia.

METHODS

Dental caries prevalence was recorded for 5- to 7-year-old children, living in the three study locations, by six trained and calibrated examiners in 2008, 2010 and 2012. A questionnaire recorded demographic data, toothbrushing behaviour and sugary drink consumption. Caries experience was measured using the decayed, missing, and filled teeth (dmft) index for primary teeth, the percentage of children who were caries free and the significant caries index. Univariate analysis was undertaken to determine independent predictors of caries.

RESULTS

The caries prevalence changed over time. In 2008, the mean dmft index was 1.40 for the fluoridated area, 2.02 for the area about to fluoridate and 2.09 for the unfluoridated control. By 2012, these mean dmft scores were 0.69, 0.72 and 1.21, respectively. In the two areas where children received fluoridated water, the significant caries index was 2.30 for the fluoridated area and 2.40 for the newly fluoridated area. The significant caries score for children in the unfluoridated location was 3.93. Multivariate analysis showed that over time the differences in dental caries prevalence between the established fluoride area and the newly fluoridated area diminished. However, children in the unfluoridated control area continued to demonstrate significant differences in the mean number of decayed teeth compared with children in the fluoridated comparator sites, and the proportions of children free from decay were significantly higher in the fluoridated areas than in the unfluoridated area.

CONCLUSION

Fluoridation of public water supplies in Gosford and Wyong offers young children better dental health than those children who do not have access to this public health measure.

Factors attributable for the prevalence of dental caries in Queensland children

BACKGROUND

Dental caries is a multifactorial condition, prevention of which requires comprehensive understanding of both contextual and compositional determinants and their population impact.

AIMS

To investigate contextual and compositional factors associated with the prevalence of dental caries in children and to estimate the population impact of those factors.

METHODS

Children in one Australian state were selected through stratified random sampling selection in 2010-2011. Oral epidemiological examinations provided individual-level outcomes: prevalence of dental caries in the primary (among 5- to 8-year-olds) and permanent dentitions (9- to 14-year-olds). Socioeconomic status, oral health behaviours and practices and dietary patterns were explanatory factors at the individual-level, school-level and area-level fluoridation status. Three-level multilevel multivariable models were sequentially specified for the prevalence of dental caries to estimate prevalence ratios (PR) associated with explanatory factors, adjusting for covariates and between- and within-group variances. Population attributable fraction (PAF) was estimated as the population impact of the statistically significant explanatory factors.

RESULTS

Data from 2214 5- to 8-year-olds and 3186 9- to 14-year-olds from 207 schools in 16 areas were analysed. The prevalence of dental caries in the primary and the permanent dentitions was 47.1% (43.9-50.4) and 38.8% (36.1-41.6), respectively. The highest prevalence of dental caries was observed in the nonfluoridated areas. In bivariate associations, factors at three levels were associated with prevalence of dental caries. In the full models, children in the nonfluoridated areas had significantly higher prevalence of dental caries [PR for the primary: 1.29 (1.11-1.50); PR for the permanent 1.49 (1.01-2.21)] compared with children in fluoridated areas, controlling for other factors. PAF estimates indicated that lack of water fluoridation attributed to 21% and 31% of primary and permanent dental caries, respectively in this child population.

CONCLUSION

A multitude of factors had significant population impact on the prevalence of dental caries in children. Water fluoridation has a significant population impact on dental caries experience in this child population.

Cyclic mechanical loading promotes bacterial penetration along composite restoration marginal gaps

OBJECTIVES

Secondary caries is the most common reason for composite restoration replacement and usually forms between dentin and the filling. The objective of this study was to investigate the combined effect of cyclic loading and bacterial exposure on bacterial penetration into gaps at the interface between dentin and resin composite restorative material using a novel bioreactor system and test specimen design.

METHODS

Human molars were machined into 3mm thick disks with 2mm deep × 5 mm diameter cavity preparations into which composite restorations were placed. A ∼ 15-30 μm (small) or ∼ 300 μm wide (large) marginal gap was introduced along half of the interface between the dentin and restoration. Streptococcus mutans UA 159 biofilms were grown on each sample prior to testing each in a bioreactor both with and without cyclic loading. Both groups of samples were tested for 2 weeks and post-test biofilm viability was confirmed with a live-dead assay. Samples were fixed, mounted and cross-sectioned to reveal the gaps and observe the depth of bacterial penetration.

RESULTS

It was shown that for large gap samples the bacteria easily penetrated to the full depth of the gap independent of loading or non-loading conditions. The results for all cyclically loaded small gap samples show a consistently deep bacterial penetration down 100% of the gap while the average penetration depth was only 67% for the non-loaded samples with only two of six samples reaching 100%.

SIGNIFICANCE

A new bioreactor was developed that allows combining cyclic mechanical loading and bacterial exposure of restored teeth for bacterial biofilm and demineralization studies. Cyclic loading was shown to aid bacterial penetration into narrow marginal gaps, which could ultimately promote secondary caries formation.

Flagellin-PAc Fusion Protein Inhibits Progression of Established Caries

Dental caries remains one of the most common infectious diseases of humankind, which develops slowly throughout life, affecting children, adolescents, and adults. A vaccine against caries is urgently needed. We previously developed recombinant flagellin as a mucosal adjuvant for anti-Streptococcus mutans vaccines by nasal immunization. Furthermore, we demonstrated a fusion protein strategy that combined flagellin and the target surface adhesion protein (PAc) in a single construct. This construct enhanced specific IgA responses in oral fluids and provided improved prophylactic protection against caries. In the present study, we observed prolonged progression of dental caries in rats after S. mutans Ingbritt challenge. In addition, we observed a therapeutic effect of the flagellin-PAc fusion protein (KF-rPAc) against dental caries as a mucosal vaccine with a new immunization protocol. The present study demonstrated that KF-rPAc by nasal immunization can promote PAc-specific systemic and mucosal antibody responses and inhibit dental caries progression efficiently after the implant of S. mutans into the oral cavity of the rats. The rats immunized with KF-rPAc exhibited 53.9% caries reduction compared with the sham-immunized rats. Our data support the concept of administration of KF-rPAc to humans after infection and even caries that has begun to alleviate caries progression. In conclusion, our study demonstrated that KF-rPAc could be used as an anticaries therapeutic mucosal vaccine.

Modern management of dental decay in children and adolescents - a review

Health is a right that requires responsible individual actions. Oral health corresponds to an important part of general health, even if for a large majority of people healthy teeth are equal with beautiful teeth. For children and adolescents "having an attractive smile" is synonymous with social acceptance and success. Dental decay has a high incidence in children in our country and progress in decay prevention, diagnosis and treatment is not reflected in children and adolescents' oral health. It is established by studies conducted by dentists and psychologists that dental decay can affect the quality of life by engendering specific eating behaviors, particular ways of speech or smile and unfortunately pain. The aim of this article is to emphasize the modern approach of dental decay in line with principles of non-invasive strategies. An important element to be considered - prophylactic methods - must be included in every treatment plan, in order to control individual caries risk. The time invested in prevention during childhood represents a real benefit for the future adult's oral health. Many a dental problems can be avoided if dental decay management relies on the link between medical science and every day practice.