Caries Protection Research Articles

New Nano-Crystalline Hydroxyapatite-Polycarboxy/Sulfo Betaine Hybrid Materials: Synthesis and Characterization.

Hybrid materials based on calcium phosphates and synthetic polymers can potentially be used for caries protection due to their similarity to hard tissues in terms of composition, structure and a number of properties. This study is focused on the biomimetic synthesis of hybrid materials consisting of hydroxiapatite and the zwitterionic polymers polysulfobetaine (PSB) and polycarboxybetaine (PCB) using controlled media conditions with a constant pH of 8.0-8.2 and Ca/P = 1.67. The results show that pH control is a dominant factor in the crystal phase formation, so nano-crystalline hydroxyapatite with a Ca/P ratio of 1.63-1.71 was observed as the mineral phase in all the materials prepared. The final polymer content measured for the synthesized hybrid materials was 48-52%. The polymer type affects the final microstructure, and the mineral particle size is thinner and smaller in the synthesis performed using PCB than using PSB. The final intermolecular interaction of the nano-crystallized hydroxyapatite was demonstrated to be stronger with PCB than with PSB as shown by our IR and Raman spectroscopy analyses. The higher remineralization potential of the PCB-containing synthesized material was demonstrated by in vitro testing using artificial saliva.

Assessment of the Ability of Desensitizing and Conventional Mouth Rinses to Promote Dentin Tubule Occlusion.

This study aimed to evaluate the effect of desensitizing and conventional mouth rinses on dentin tubule occlusion. Dentin hypersensitivity was simulated by EDTA application for five minutes. The specimens were randomly allocated into the following groups: desensitizing mouth rinses (Colgate Sensitive, Elmex Sensitive Professional, Listerine Advanced Defense Sensitive, Sensodyne Cool Mint); conventional mouth rinses (Colgate Plax, Elmex Caries Protection, Listerine Anticaries, Sensodyne Pronamel); a negative control (C-: distilled water); and Clinpro XT Varnish was the positive control (C+). Subsequently, the specimens were submitted to an erosive or abrasive challenge (performed separately) and to an erosive/abrasive cycling for five days (n=10 for each challenge). After treatment, challenges, and cycling, the specimens were analyzed in an environmental scanning electron microscope to verify the number of open dentin tubules (ODTs), counted by using Image J software (National Institutes of Health, Bethesda, MD, USA). Data were analyzed by the Kruskal-Wallis, Friedman and Dunn tests, with Bonferroni correction (α=0.05). Groups did not differ at baseline (p>0.05). At the post-treatment, erosion and abrasion stages, C+ was the only group that showed a reduction in ODTs compared to C-(p<0.05). In the other groups, numbers did not differ significantly from C- (p>0.05). After cycling, none of the groups exhibited significant reduction in ODTs other than C- (p>0.05); however, C+, Listerine Anticaries, and Colgate Plax had a lower number of ODTs than Listerine Sensitive and Sensodyne Pronamel. No mouth rinse was able to promote significant occlusion of the dentin tubules after treatment and the challenges. C+ was the only product that effectively promoted tubular occlusion, but this effect did not withstand several erosive and abrasive challenges.

Zusammenhang zwischen Stilldauer und Early Childhood Caries

Background: Dental caries in primary dentition affects approximately 500 million children worldwide, which makes it a serious global public health issue. Considering this background and the high caries prevalence in childhood, further research is needed to understand the influence of breastfeeding on caries development.Objectives: Aim of this study was to evaluate the association between breastfeeding duration (exclusive and then subsequent partial breastfeeding) and caries in the primary dentition considering socioeconomic status (SES), age, body mass index (BMI), and oral hygiene as potential confounders.Materials and methods: This cross-sectional study was part of the LIFE Child project and it analyzed data from 597 children aged 1-5 years (50.4% male, 99.7% born in Germany). A PC-based standardized questionnaire was used to collect information on sociodemographic data and breastfeeding behavior. The body mass index (BMI) was adjusted to age from weight and height. Visible plaque index (VPI), malocclusion and caries (dmf-t [decayed, missing due to caries, and filled teeth] according to WHO [World Health Organization] diagnosis criteria) were clinically collected. The statistical analysis was calculated using chi square and t-test, and multivariable logistic regression, respectively. Results: The caries frequency in this sample was 9.9% (n=59/597), the mean dmf-t ± SD (standard deviation) was 0.27 ± 1.1. The duration of exclusive/partial breastfeeding (± SD) was 4.5 ± 4.7 and 9.3 ± 7.7 months, respectively. Children from families with a low SES were breastfed for significantly shorter periods of time (1.2 months for exclusive and 3.3 months for partial breastfeeding, p<0.05). The bivariate analyses showed caries protection when breastfed 6-12 months (odds ratio [OR]=0.5; 95% confidence interval [CI]: 0.3-0.9), but in the multivariable analyses the effect disappeared; significant influencing factors were plaque (OR=9.8, 95% CI: 5.1-18.8), low SES (OR=2.3, 95% CI: 1.0-5.3), and age (OR=2.0, 95% CI: 1.5-2.6). Conclusion: The analyzed parameters showed that poor oral hygiene and low SES are risk factors for caries in the primary dentition. Duration of exclusive/partial breastfeeding had no effect on caries development in this study.Keywords:Breastfeeding, Caries, Cross-sectional study, Socioeconomic status, Dental plaque

Assessment of dental caries using caries assessment spectrum and treatment index in children of age 5-10 years

Introduction: Dental caries is the most prevalent disease of oral health in school-aged children around the world. Although different caries detection/diagnosis criteria are available, none of them includes the total spectrum of dental caries (which ranges from a sound tooth to tooth loss due to caries) other than caries assessment spectrum and treatment (CAST) Index. CAST index covers the total dental caries spectrum from no carious lesion through caries protection (sealant) and caries cure (restoration) to carious lesions in enamel and dentin, and the advanced stages of carious lesion progression in pulp and tooth surrounding tissue. Methodology: A cross-sectional study was conducted among children of age 5–10 years to detect the prevalence of dental caries using CAST index in Panchayat Union Primary School in Sundharipalayam and Koot-road (east), Villupuram. A total of 100 samples were selected based on inclusion criteria. Results: Only 33% had sound dentition, 0% had sealant and restoration, presence of caries in enamel and/or dentine ranged from 9% to 33%. Pulpal involvement was observed in 13% and abscess/fistula was present in 7% of participants in at least one tooth. 5% had lost at least one tooth due to caries. Conclusion: CAST index has been found useful in epidemiological surveys, especially in recording early carious lesions. Developers of the CAST index should throw more light on the treatment needs part of the index as well as how each code of this index can be utilized in controlling dental caries in a community.

Estimation of Flouride Concentration in Drinking Water Sources of Bhilai, Chattisgarh

Background: Fluoride has always been considered as a “double edged sword”. The optimum and judicious use of fluoride has resulted in caries protection whereas injudicious use has resulted in chronic fluoride toxicity, which manifests as dental and skeletal fluoride. Dental fluorosis occurring due to drinking water with high concentration of fluoride is a common public health problem in India. Hence the present study was designed with an aim to estimate fluoride concentration in drinking water source of the people from Bhilai, Chattisgarh. Aim: To estimate fluoride concentration in drinking water source of the people from Bhilai, Chattisgarh. Material and Methods: Eight different samples of ground water was collected from bhiali, Chattisgarh, which is divided into four different areas: kurud (north), Maroda (south), Charoda (east), Nehrunagar (west); all these samples were tested by HI-96759-11 portable photometre and the fluoride concentration was determined. All the data obtained was then further subjected to statistical analysis and a conclusion was inferred regarding the fluoride concentration of drinking water source of the people of Bhilai, Chattisgarh which is essential for an effective fluoride regimen for prevention of dental caries in children. Result: Highest fluoride concentration in Bhilai is found to be 0.52 ± .056 ppm and the lowest being 0.31 ± .148 ppm. So, the fluoride concentration of the ground water in Bhilai is found to be in the range of 0.3-o.6 ppm. Thus, it does not possess any chance to cause dental fluorosis in the people of Bhilai. However, a fluoride supplementation of 0.25mg/day for 3-6yrs children and 0.50mg/day for 6-16yrs children can be done to enhance the prevention of dental caries in the children residing in Bhilai, Chattisgarh.

Pyrophosphates in toothpaste: a retrospective and reappraisal.

During the last 50 years, an increasing number of toothpastes have been marketed that include pyrophosphates as anti-tartar (calculus) agents. Pyrophosphates are chelating agents with low toxicity and a broad range of applications, such as food additives and in industrial applications. Like other chelating agents, the prime function is to combine with metal elements and, in toothpastes, to inhibit calcium phosphate deposits in the form of dental calculus. It is well established that pyrophosphates inhibit crystal growth of hydroxyapatite in bones and teeth, and theoretically may negatively affect the demineralisation-remineralisation equilibrium at the tooth surface. Surprisingly, little clinical research has been carried out to assess if the caries protection provided by fluoride toothpaste is compromised by the inclusion of pyrophosphates and the existing evidence is inconsistent. In the absence of more clinical research, it is suggested that children should not use pyrophosphate-containing toothpastes under 12 years of age.

Erosive/Abrasive Enamel Wear While Using a Combination of Anti-Erosive Toothbrush/-Paste.

To investigate dental enamel wear caused by erosion and abrasion while using a combination of anti-erosive toothbrush/-paste. A total of 60 enamel specimens from bovine incisors were randomly assigned into five groups of 12 specimens each (G1-5, n = 12): (G1) control group (no treatment), (G2) standard medium toothbrush Paro M43 and standard toothpaste Elmex Caries Protection, (G3) standard medium toothbrush Paro M43 and anti-erosive toothpaste Elmex Protection Erosion, (G4) anti-erosive toothbrush Elmex Erosion Soft and standard toothpaste Elmex Caries Protection, (G5) anti-erosive toothbrush Elmex Erosion Soft and anti-erosive toothpaste Elmex Protection Erosion. Initially, surface baseline profiles were recorded using profilometry. In a total of 60 cycles, all specimens were exposed to hydrochloric acid (pH = 3) for 1 min, rinsed with tap water to stop the erosive attack and brushed according to the specific protocol of each group (15 brushing strokes per run). Enamel loss was determined by comparing the surface profiles before and after 60 cycles and the results were statistically analysed using analysis of variance (ANOVA). The significantly highest loss of enamel was observed in the control group G1(1.4 ± 0.20 µm) (p < 0.001). G2 turned out to be the most abrasive toothbrush/-paste combination (1.12 ± 0.15 µm), G3 the least invasive (0.40 ± 0.04 µm) (p < 0.001, respectively). All combinations of the investigated toothbrushes/-pastes reduce erosive/abrasive enamel wear. However, the highest reduction was observed for the combination of anti-erosive toothpaste and standard toothbrush (G3).

FimH as a mucosal adjuvant enhances persistent antibody response and protective efficacy of the anti-caries vaccine

ObjectiveTo investigate whether the recombinant FimH-S.T protein could modulate immune response to anti-caries vaccine in vitro and in vivo. DesignRecombinant FimH protein derived from Salmonella was constructed and purified. The expression of dendritic cell maturation markers and cytokines release were performed by flow cytometry, Real-time PCR and ELISA. In addition, BALB/c mice were administered with anti-caries PAc vaccine plus FimH-S.T, antibody responses were evaluated by ELISA. Splenocytes of immunized mice were detected for their proliferative ability in response to in vitro retreatment with PAc antigen by flow cytometry. Caries protection against dental caries formation was also investigated. ResultsThe purified FimH-S.T induced phenotypic maturation of DC2.4 by up-regulating the expression of costimulatory molecules and MHC II, provoked the production and secretion of cytokines via TLR4-dependent signaling pathway in vitro. Furthermore, the mice immunized with the mixture of FimH-S.T and PAc significantly enhanced the PAc-specific antibodies in the serum along with saliva and promoted splenocyte proliferation. Our results also confirmed that PAc+FimH-S.T decreased the caries lesions formation which provided high protective efficacy against dental caries. ConclusionOur study demonstrates that recombinant FimH-S.T could enhance specific IgA responses and protection of anti-caries vaccine, possessing mucosal adjuvant ability by activating DC2.4 via TLR4 signaling pathway.

Effectiveness of caries-preventing agents on initial carious lesions within the scope of orthodontic therapy

ObjectiveTo evaluate the effectiveness of three different caries-preventing agents on artificial caries in a Streptococcus mutans-based caries model.MethodsSixty-five caries-free human molar enamel blocks were treated with a demineralization solution and a remineralization solution. The specimens were assigned to the following groups according to the caries-protective product applied: group A, chlorhexidine varnish; group B, fluoride-releasing chemically cured sealant; group C, fluoride-releasing lightcured sealant; group D, positive control (specimens that were subjected to de- and remineralization cycles without treatment with any caries-protective agents); and group E, negative control (specimens that were not subjected to de- and remineralization cycles). Samples in groups A–D were stored in demineralization solution with S. mutans and thereafter in artificial saliva. This procedure was performed for 30 days. Average fluorescence loss (ΔF) and surface size of the lesions were measured using quantitative light-induced fluorescence at baseline and on the 7th, 14th, and 30th days.ResultsAfter 30 days, group A demonstrated a significant increase in ΔF and the surface size of the lesions, no significant difference in comparison with the positive control group, and a significant difference in comparison with the negative control group. Group B showed no significant changes in both parameters at any of the measurement points. While group C showed increased ΔF after 14 days, no significant fluorescence change was observed after 30 days.ConclusionsBoth fluoride-releasing sealants (chemically or light-cured) show anti-cariogenic effects, but the use of chlorhexidine varnish for the purpose of caries protection needs to be reconsidered.

Assessment of fluoride intake from drinking water and toothpaste in 3-year-olds: Preliminary results in Belgrade, Republic of Serbia

Background/Aim. Fluoride has beneficial effect on dental caries prevention and enables high hardness of enamel. However, fluoride intake above optimal levels can have adverse effects on teeth and bones, especially in young children during the period of intense growth and teeth development. The aim of this study was to assess fluoride intake from water and toothpaste among 3-year-old children in Belgrade, Serbia, in the municipalities of Vracar and Novi Beograd. Methods. A questionnaire for the parents (n = 40) was used to provide information on the water consumption (tap and/or bottled water) and the brand of toothpaste used by children as well as the frequency of tooth brushing and the amount of toothpaste during brushing. Fluoride concentrations in water and toothpaste samples were determined electrochemically by using fluoride-selective electrode. Fluoride intake was estimated through a mathematical model commonly used by the U.S. Environmental Protection Agency. Results. The obtained results indicate no significant difference in daily fluoride intake through drinking water and toothpaste in 3-year-old children in Vracar (n = 19) compared to Novi Beograd (n = 21) (p &gt; 0.05). However, all estimated fluoride levels (0.089?0.625 mg/day) are significantly lower than the optimal daily intake level for caries protection (0.7 mg/day for children up to 4 years, FNB-USA National Institute of Medicine) and two to six times lower than tolerable upper fluoride level for the children of same age (1.3 mg/day, FNB-USA National Institute of Medicine). Furthermore, calculated daily fluoride intake per kilogram body weight confirm very low fluoride intake by water and toothpaste in children of investigated municipalities in Belgrade, being significantly below the recommended an adequate intake (0.05 mg/kg/day, EFSA). Conclusion. This preliminary study has shown that daily fluoride intake in 3-year-olds is lower than tolerable upper fluoride level, even not sufficient for the prevention of dental caries.

Glass-ionomer fissure sealants: Clinical observations up to 13 years

ObjectivesThe aim of this study was to clinically examine the retention and caries-preventive effect of a glass-ionomer material for fissure sealing in newly erupted permanent molars. MethodsA total of 1736 newly erupted permanent molars were sealed in 480 children aged 5–15 years. Sealants were evaluated yearly and recorded as “completely retained”, “partially retained”, or “completely lost”. Teeth were also evaluated for presence of caries. ResultsSealants were observed for 2–13 years. The mean follow-up time was 5 years. After one year, 69% of the sealants were fully retained and 21% were partially retained. Thereafter, the cumulative retention rate decreased. Starting from 8th year of follow-up, no “completely retained” sealant could have been observed. At the end of the 13-year follow-up period, 76% of sealants were “completely lost”. On the other hand, 99% and 65% of observed occlusal surfaces were caries-free after one and 13 years, respectively. During the observation period, 62 teeth developed caries in surfaces other than occlusal. Survival rates were significantly better for second permanent molars than for first permanent molars (p < 0.001). No influence of caries risk on caries incidence has been noted. ConclusionsAlthough the retention rate of the glass-ionomer material for fissure sealing was low, it appears to have prevented dental caries in 65% of newly erupted permanent molars evaluated after thirteen years of placement. Clinical significanceThe present study reports long-term clinical performance of glass-ionomer fissure sealants in patients with low, moderate and high caries-risk. The study shows that caries risk does not influence survival of glass-ionomer sealants, which proved to be beneficial for long-term caries protection.

The association of Enamelin, Lactoferrin, and Tumour necrosis factor alpha gene polymorphisms with high caries susceptibility in Chinese children under 4 years old

ObjectiveThe aim of this study was to assess the role of ENAM rs3796703, LTF rs1126478, and TNF-α rs1800629 in high caries susceptibility. DesignThe present case–control study included 1005 unrelated children under 4 years old: 505 with severe caries (dmft index ≥4) and 500 who were caries-free (dmft index=0 and without white-spot lesions). Questionnaires were obtained from parents and gardians about the children’s diet and oral behavioural habits. All the children received dental examinations and oral swabbing for human genomic DNA collection. ENAM rs3796703, LTF rs1126478, and TNF-α rs1800629 were genotyped by Sanger sequencing. ResultsThe frequency of the ENAM rs3796703T allele (6.7% in the caries group and 4.2% in the caries-free group), CT genotype (12.7% in the caries group and 8.4% in the caries-free group), TNF-α rs1800629 A allele (4.8% in the caries group and 6.8% in the caries-free group), and AG genotype (8.7% in the caries group and 13.2% in the caries-free group) were significantly different between the caries and caries-free groups (p<0.05). No significant difference was found in the LTF rs1126478 allele frequency and genotype distribution between the two groups. The ENAM rs3796703 CT genotype increased caries susceptibility by 60.9% compared to the CC genotype (β=0.746, OR=1.609), and the TNF-α rs1800629 AG genotype reduced caries susceptibility by 47.4% compared to the GG genotype (β=−0.642, OR=0.526). In terms of habits covariates, prolongation of night feeding time by 1 month increased caries susceptibility by 3.3% (β=0.033, OR=1.033); additionally, sweets and acidic drinks consumption 1–2 times per day increased caries susceptibility by 218.2% (β=1.158, OR=3.182), and consumption 3 or more times pe/r day increased susceptibility by 883.5% (β=2.286, OR=9.835) compared to non-consumption. Topical fluoride application decreased caries susceptibility by 43.0% (β=−0.562, OR=0.570). ConclusionsThe ENAM and TNF-α genes are likely associated with caries experience in Chinese children. The ENAM rs3796703 CT genotype might be involved in caries susceptibility, while TNF-α rs1800629 AG genotype might be involved in caries protection.

Caution needed in altering the 'optimum' fluoride concentration in drinking water.

The US Public Health Service has finalized its recommendation relating to community water fluoridation (Federal Panel on Community Water Fluoridation, US Department of Health and Human Services, 2015). It recommends an optimal concentration of 0.7 mg/l F based on their argument that this concentration provides the best balance of protection from dental caries while limiting the risk of dental fluorosis. The rationale for this recommendation can be questioned, particularly given the contrasting etiologies and impact on the community. Uncertainty surrounds the key evidence considered by the panel. This study argues that the panel should have exercised more caution and called for further research before reducing the 'optimal' concentration of fluoride in water supplies. Up-to-date data on caries and fluorosis trend by age group or birth cohort, analyses on attributable risk for fluorosis, data on individual and population impact of caries and fluorosis, water intake over an extended period across the seasons, and the curvilinear relationship of fluoride concentration in water supplies and caries protection would have all been desirable to inform the panel, given the foreshadowing of the recommendation in late 2011. Further, a wider range of policy directions to achieve the best balance of protection from dental caries while limiting the risk of dental fluorosis are available from the international literature. Assessment of these should have been more evident. There is a public health policy responsibility to monitor water fluoridation programs so as to achieve a near maximum reduction in dental caries without unacceptable levels of dental fluorosis. However, recommendations to alter existing policy need to be cognizant of the balancing of risk and protective exposures across the entire population and potentially all ages and to be based on recent data that are purposefully collected, critically analyzed and carefully interpreted.

Report on the clinical technique of thermo-curing glass-ionomer sealant.

Controversy exists regarding the general safety of resin sealants and in particular their use in children, due to the possible leaching of non-polymerized monomers including bisphenol A. A thermally cured high-viscosity glass-ionomer cement (GIC) is suggested as a first-choice sealant material. An innovative approach of thermo-curing the GIC during placement is presented. The step-by-step clinical procedure and rationale for the biomimetic thermo-cured glass-ionomer fissure sealant are introduced and described. A thermally cured GIC sealant may provide long-term caries protection to fissures and pits without the need to maintain and reseal. GICs are both biocompatible and biomimetic resulting in formation of fluorapatite, the ultimate protection against dental caries.

Lactotransferrin Gene Polymorphism Associated with Caries Experience

Dental caries is a common multifactorial disease, resulting from the interaction of biofilm, cariogenic diet and host response over time. Lactotransferrin (LTF) is a main salivary glycoprotein, which modulates the host immune-inflammatory and antibacterial response. Although a genetic component for caries outcome has been identified, little is known over the genetic aspects underlying its susceptibility. Thus, the aim of this study was to investigate the association between LTF polymorphisms and caries susceptibility. Six hundred seventy seven 12-year-old students were selected: 346 with (DMFT ≥ 1) and 331 without caries experience (DMFT = 0). Also, individuals concentrating higher levels of disease (polarization group, DMFT ≥ 2, n = 253) were tested against those with DMFT ≤ 1 (n = 424). Along with clinical parameters, three representative LTF tag SNPs (rs6441989, rs2073495, rs11716497) were genotyped and the results were evaluated using univariate and multivariate analyses. Allele A for tag SNP rs6441989 was found to be significantly less frequent in the polarization group, conferring a protective effect against caries experience [AA + AG × GG (OR: 0.710, 95% CI: 0.514-0.980, p = 0.045)], and remained significantly associated with caries protection in the presence of gingivitis (p = 0.020) and plaque (p = 0.035). These results might contribute to the understanding of the genetic control of caries susceptibility in humans.

Dental Caries and Enamelin Haplotype

In the literature, the enamelin gene ENAM has been repeatedly designated as a possible candidate for caries susceptibility. Here, we checked whether ENAM variants could increase caries susceptibility. To this aim, we sequenced coding exons and exon-intron boundaries of ENAM in 250 children with a severe caries phenotype and in 149 caries-free patients from 9 French hospital groups. In total, 23 single-nucleotide polymorphisms (SNPs) were found, but none appeared to be responsible for a direct change of ENAM function. Six SNPs had a high minor allele frequency (MAF) and 6 others were identified for the first time. Statistical and evolutionary analyses showed that none of these SNPs was associated with caries susceptibility or caries protection when studied separately and challenged with environmental factors. However, haplotype interaction analysis showed that the presence, in a same variant, of 2 exonic SNPs (rs7671281 and rs3796704; MAF 0.12 and 0.10, respectively), both changing an amino acid in the protein region encoded by exon 10 (p.I648T and p.R763Q, respectively), increased caries susceptibility 2.66-fold independent of the environmental risk factors. These findings support ENAM as a gene candidate for caries susceptibility in the studied population.

Colour improvement and stability of white spot lesions following infiltration, micro-abrasion, or fluoride treatments in vitro

White spot lesions (WSLs) are unwelcome side effects of fixed appliances that compromise the treatment outcome. Recently, infiltration of WSLs has been introduced as a viable treatment alternative. The objective was to evaluate the colour improvement of WSLs and their stability against discolouration following infiltration, fluoride, or micro-abrasion treatments in vitro. Artificial WSLs were created in bovine enamel (N = 96) using acidic buffer solution (pH 5, 10 days) and were randomly allocated to four groups. Specimens were treated with infiltration (Icon, DMG), fluoride (Elmex Caries Protection, GABA), and micro-abrasion (Opalustre, Ultradent) or remained untreated (control). Groups were discoloured for 24 hours in tea or tea + citric acid. Colour components and visible colour change (L*, a*, b*, ΔE) were measured spectrophotometrically on following time points: baseline, after WSL formation, after treatment, and during discolouration (8, 16, and 24 hours). Data were analysed using Kruskal-Wallis and Mann-Whitney tests. WSL formation increased (L*) in all groups. Only infiltration reduced this effect to baseline. Highest ΔE improvement was obtained by infiltration and micro-abrasion followed by fluoride. This improvement was stable only for infiltration during discolouration. L*, a*, and b* changed significantly during discolouration in all groups except infiltration. Within the same treatment group, discolouration solutions did not differ significantly. In vitro testing cannot replicate the actual mode of colour improvement or stability but can be used for ranking materials and techniques. Infiltration and micro-abrasion treatments were capable of diminishing the whitish appearance of WSLs. Only infiltrated WSLs were stable following discolouration challenge.

Pit and fissure sealants in pediatric dentistry

Caries on the occlusal surface of dentition is a significant dental health problem. Molars and premolars are the most vulnerable teeth to caries attack. The high susceptibility of these teeth to caries is directly related to morphology of their occlusal surface. Fluoride's great success in preventing tooth decay on smooth surfaces has made dental caries largely a disease of rough irregularities. Enamel surfaces with pits and fissures receive minimal caries protection from either systemic or topical fluoride agents, the reason for ineffectiveness of fluorides in the pit and fissure caries may be related to the differences in enamel thickness and the inaccessibility of the base of pits and fissures to topical fluorides. The most efficient way to prevent pit and fissure caries is by effectively sealing the fissures using resins called pit and fissure sealants.

The Caries Assessment and Treatment (CAST) instrument.

To describe the 'Caries Assessment Spectrum and Treatment' (CAST) instrument, its origin and content, and to provide an example of how results can be reported. The CAST instrument covers the complete range of stages of carious lesion progression: from no carious lesion, through caries protection (sealant) and lesion care (restoration) to lesions in enamel and dentine, the advanced stages of carious lesion progression in pulpal and its consequences on tooth-surrounding tissue and tooth loss due to caries. Using the RAND modified e-Delphi consensus method two independent panels, comprising a total of 56 epidemiologists from 27 countries, determined the face and content validity of CAST. Panellists assessed 17 statements related to the content, description, suitability and international use of CAST. Agreement of 75% or higher was required for reaching consensus on a statement. Construct validity and reliability testing of CAST have been carried out, but results are not yet available. All 17 statements were approved by the panellists, who found the RAND modified e-Delphi consensus method suitable for achieving consensus. The CAST codes were ordered hierarchically. External validity was obtained. Reporting using CAST can be performed for orally healthy dentitions and those having morbidity and mortality. A DMF score can easily be calculated from the CAST codes, thereby enabling retention of the use of existing DMF scores. The CAST instrument for use in epidemiological surveys is very promising. Face and content validation is obtained. Construct validity and reliability testing will be completed soon. A structure for reporting results in a comprehensive, pragmatic and easily understood way is being developed.

The Caries Assessment Spectrum and Treatment (CAST) index: rational and development

Serious difficulties in reporting results were encountered when using ICDAS II and PUFA separately in an epidemiological survey in a child population in Brazil. That necessitated the development of a comprehensive but pragmatic caries assessment index. This publication describes the rationale, development and content of a novel caries assessment index. Strengths and weaknesses of ICDAS II, PUFA and other indices were analysed. The novel caries index developed for use in epidemiological surveys is termed 'Caries Assessment Spectrum and Treatment' (CAST). 'Spectrum' indicates what is considered the main strength of the new index - its usefulness in describing the complete range of stages of carious lesion progression: from no carious lesion, through caries protection (sealant) and caries cure (restoration) to lesions in enamel and dentine, and the advanced stages of carious lesion progression in pulpal and tooth-surrounding tissue. CAST combines elements of the ICDAS II and PUFA indices, and the M- and F-components of the DMF index. A DMF score can easily be calculated from the CAST score, thereby enabling retention of the use of existing DMF scores. The CAST index for use in epidemiological surveys is very promising. It should be validated and its reliability and usefulness be tested in different age groups in different countries and cultures.