Thylstrup-Fejerskov Index Research Articles

Comparison of case-based and lecture-based learning in dental fluorosis diagnostic ability with visual analog scale assessment

ObjectiveThis study aimed to compare the impact of case-based learning (CBL) versus lecture-based learning (LBL) on dental students' clinical decision-making regarding DF severity using Visual Analog Scale (VAS) scoring.MethodsEighty first-year graduate dental students were randomly assigned to either the CBL (n = 38) or LBL (n = 42) groups. Both groups received instruction on DF diagnosis, with CBL involving small group sessions analyzing real cases and LBL involving traditional lectures. Effectiveness was assessed by presenting 32 dental fluorosis cases with Thylstrup-Fejerskov Index (TSIF) scores ranging from 0 to 7 through slide presentations to both groups for VAS assessment. Five evaluators of each group randomly selected were asked to repeat the rating 2 weeks later. Statistical analysis included two-way ANOVA for group and gender differences, intra-class correlation coefficient (ICC) for reliability, and Spearman correlation coefficients for validity.ResultsVariations in VAS scores were observed between CBL and LBL groups, with no significant gender impact. Excellent inter- and intra-evaluator agreement was found for VAS scoring in both groups, indicating its reliability. Validation against established indices (such as DI and TSIF) demonstrated strong correlations, with CBL students exhibiting higher correlations.ConclusionsCBL enhances students' clinical decision-making and proficiency in DF diagnosis, as evidenced by more consistent and accurate VAS scoring compared to LBL. These findings highlight the importance of innovative educational strategies in dental curricula, with implications for improving training quality and clinical outcomes.Trial registration: The study was registered at the Clinical Research Center, Hospital of Stomatology, Wuhan University (Registration code: HGGC-036).

Caries prevalence and water fluoridation in Israel: a cross-sectional study.

To assess the effect of Community Water Fluoridation (CWF) in the prevalence of dental caries and dental fluorosis in 12-year-old children living in Israel. Considering that CWF is important in the prevention of dental caries. Between 2002 and 2014, the water in communities of at least 5,000 individuals was fluoridated. In 2014, CWF in Israel stopped. Data on 12-year-old children from all areas in Israel from the national cross-sectional epidemiological survey conducted in 2011 to 2012 were stratified by city water fluoridation and by city and school socioeconomic status. Two dependent variables were defined: (1) DMFT index of caries experience in the permanent dentition; (2) dental fluorosis in central incisors using the Thylstrup-Fejerskov classification of fluorosis. Data from 2,181 12-year-olds were analyzed. The average DMFT was 1.17 ± 1.72, and 49% were caries-free. Based on DMFT, the caries experience was significantly higher in nonfluoridated cities (1.38 vs 0.98 in fluoridated cities) and there were more caries-free children in fluoridated cities (56.4% vs 40.6% in nonfluoridated). DMFT was higher in cities with lower socioeconomic status than high socioeconomic status (1.29 vs 1.05, respectively, P < .001) and there were fewer caries-free children in low socioeconomic status cities (44.5% vs 53.0% in high socioeconomic status cities, P < .0001). Almost all the 10.3% of children with signs of fluorosis (scoring at least 1 in the Thylstrup-Fejerskov index), had questionable to mild fluorosis (9.3%). CWF is a cheap, simple method of dental health protection that reaches all socioeconomic levels, and cessation of water fluoridation reduced the health of Israel's children. Water fluoridation provides substantial caries prevention, by reaching a substantial number of people. The relevance of this work is for policymakers to consider CWF as clinically proven method for reducing health inequalities.

Caries prevalence and water fluoridation in Israel: a cross-sectionalstudy.

To assess the effect of Community Water Fluoridation (CWF) in the prevalence of dental caries and dental fluorosis in 12-year-old children living in Israel. Considering that CWF is important in the prevention of dental caries. Between 2002 and 2014, the water in communities of at least 5000 individuals was fluoridated. In 2014 CWF in Israel stopped. Data on 12-year-old children from all areas in Israel from the national crosssectional epidemiological survey conducted in 2011-2012 were stratified by city water fluoridation and by city and school socio-economic status (SES). Two dependent variables were defined: (1) DMFT index -caries experience in the permanent dentition; (2) dental fluorosis in central incisors using the Thylstrup-Fejerskov (TF) classification of fluorosis. Data from 2181, 12-year-olds was analyzed. the average DMFT was 1.17+1.72 and 49% were caries free. Based on DMFT, the caries experience was significantly higher in nonfluoridated cities (1.38 vs. 0.98 in fluoridated cities) and there were more caries free children 56.4% in fluoridated cities vs. 40.6% in non-fluoridated. DMFT was higher in cities with lower SES than high SES (1.29 vs. 1.05 respectively, p<0.001) and there were less caries free children in low SES (44.5% vs. 53% in high SES cities, p<0.0001). Almost all the 10.3% of children with signs of fluorosis (scoring at least 1 in TF index), had questionable to mild fluorosis (9.3%). CWF is a cheap, simple method of dental health protection that reaches all socio-economic levels and cessation of water fluoridation reduced the health of Israel's children. Water fluoridation provides substantial caries prevention, by reaching a substantial number of people. The relevance of this work is for policymakers to consider CWF as clinically proven method for reducing health inequalities.

Unraveling gene expression and genetic instability in dental fluorosis: Investigating the impact of chronic fluoride exposure

Chronic fluoride exposure, even in small quantities, when continuously ingested by the human population, can lead to a significant public health concern known as fluorosis. Our understanding of the effects of fluoride on human health, as well as its potential to impact DNA, is limited. The present study aimed to assess genetic instability in 20 individuals diagnosed with dental fluorosis and 20 individuals without the condition from the state of Rio Grande do Sul, Brazil. The participants' dental fluorosis was evaluated using the Thylstrup-Fejerskov index (TF). To further evaluate genetic instability, several assays were conducted, including the alkaline and modified (+FPG) comet assay (using a visual score, VS), the buccal micronucleus (MN) cytome (BMCyt) assay, the cytokinesis-block MN (CBMN-Cyt) assay, and the measurement of telomere length (TL). In addition, the study utilized tools from Systems Biology to gain insights into the effects of fluoride exposure on humans, which aided in the selection and evaluation of mRNA expression levels of specific genes, namely PPA1 (inorganic pyrophosphatase 1), AQP5 (Aquaporin 5), and MT-ATP6 (Mitochondrially Encoded Adenosine Triphosphate Synthase Membrane Subunit 6). Furthermore, fluoride levels in the blood and urine were assessed using an ion-selective electrode, along with the evaluation of the inflammatory response in serum. The group with dental fluorosis exhibited 2.18 times higher MN frequencies specifically when assessed using the CBMN-Cyt assay, in comparison with individuals without fluorosis. Findings from the enzyme-modified comet assay indicated oxidative damage to purines in DNA. Furthermore, a decrease in TL was observed, along with elevated expression patterns of the PPA1 and AQP5 genes, and significant alterations in cytokine release. Significant correlations were identified between the TF and age, as well as the levels of necrotic cells. Additionally, noteworthy correlations were established between fluoride levels and the levels of MN, VS, and MT-ATP6. Although dental fluorosis results from fluoride exposure, our research highlights the potential influence of this condition on genomic instability and gene expression. Consequently, our findings stress the importance of continuously monitoring populations with a high incidence of dental fluorosis to enhance our comprehension of how genomic instability might correlate with the origins and consequences of health problems in these individuals.

Fluorotic Enamel Susceptibility to Dental Erosion and Fluoride Treatment.

The purpose of this in vitro study was to test the hypothesis that fluoride treatment can prevent dental erosion on fluorotic enamel of different severities. It followed a 3×2 factorial design, considering a) fluorosis severity: sound (TF0, Thylstrup-Fejerskov Index), mild (TF1-2), moderate (TF3-4); and b) fluoride treatment: 0 (negative control) and 1150ppmF. Human molars with the three fluorosis severities (n=16, each) were selected and randomly assigned to the two fluoride treatments (n=8). Enamel blocks (4×4mm) were prepared from each tooth and subjected to a dental erosion cycling model, for 10 days. The daily cycling protocol consisted of erosive challenges (1% citric acid, pH 2.4), interspersed by periods of immersion in artificial saliva, and three 2-minute treatments with either 0 or 1150ppm F. The enamel volume loss (mm3) was calculated by subtracting values obtained by microtomography before and after cycling. Two-Way ANOVA showed no significant interaction between fluorosis severity and fluoride treatment (p=0.691), and no significant effect for either fluorosis severity (TF0 mean±standard-deviation: 13.5(10-2±0.42(10-2, TF1-2: 1.50(10-2±0.52(10-2, TF3-4: 1.24(10-2±0.52(10-2, p=0.416) or treatment (0ppmF: 1.49(10-2±0.53(10-2; 1150ppmF: 1.21(10-2±0.42(10-2; p=0.093), when evaluated independently. Considering the limitations of this in vitro study, the presence and severity of fluorosis in enamel do not appear to affect its susceptibility to dental erosion. Fluoride treatment was not effective in preventing the development of dental erosion in both sound and fluorotic enamel substrates under our experimental conditions.

Bond Strength Comparison Among 10-MDP-Containing and Non-10-MDP-Containing Adhesives in Different Degrees of Dental Fluorosis

Dental fluorosis can cause changes in the enamel surface, conditioning its functionality and esthetics. The application of dental adhesives is a treatment option; however, their use on fluorotic teeth can result in limitations. The aim of this study was to compare the shear bond strength of two different adhesives, one with 10-MDP and one without 10-MDP, in different degrees of dental fluorosis.This is an in vitro study on dental enamel samples, a total of 180 samples with the inclusion criteria were treated, randomly divided into two groups of 90, according to the type of dental adhesive, where each group was again divided into three groups of 30 samples, representing different degrees of dental fluorosis according to the Thylstrup-Fejerskov index (Group I: TF1 and TF2; Group II: TF3; Group III: TF4). Normality tests, two-factor ANOVA, and post-hoc tests were used to determine differences between the groups, with a significance level of 95%. As results, a statistically significant difference was shown between the use of dental adhesive with 10-MDP and the three groups of dental fluorosis (p=0.011), in addition, a Tukey post-hoc test on the groups treated with 10-MDP adhesive revealed a statistically significant difference between group I versus group II, and group I versus group III, (p=&lt;0.05). It is concluded that the use of adhesive systems with 10-MDP presents a better shear bond strength on enamel with dental fluorosis grades I and II in the Thylstrup-Fejerskov index.

Association Between Frequency and Severity of Dental Fluorosis and Molar Incisor Hypomineralization.

To assess the association between the frequency and severity of dental fluorosis (DF) and molar incisor hypomineralization (MIH) in a fluoridated salt region. In this retrospective cross-sectional study, we evaluated the buccal, occlusal/incisal, and palatal/lingual surfaces of first permanent molars and permanent incisors of 453 patients aged 13-16 years through intraoral standardized photographs. Two standardized examiners evaluated DF and MIH independently, utilizing the Thylstrup-Fejerskov (TF) index and the MIH index. The statistical analysis was performed using a generalized linear model and logistic regression adjusted for age, sex, and dental caries experience. The MIH frequency at the surface level was lower in the presence of DF (PR= 0.03; P= 0.00, 95% CI: 0.01-0.08). At the surface level, MIH severity was lower among those presenting mild DF (aOR= 0.02; 95% IC: 0.01-0.07). Regarding severe DF, we found no significant difference in MIH severity (P= 0.174). MIH frequency and severity tend to be lower in the presence of DF.

No Association was Detected between Polymorphism of COL1A2 Genes and Occurrence of Dental Fluorosis Among the Subjects Living in a Fluorosis-Endemic Area of India

Objective: To determine any genetic association of COL1A2 polymorphism and the occurrence of dental fluorosis within an Indian human dental fluorosis population. Material and Methods: Fifty-six (56) subjects from two groups i.e. cases with dental fluorosis from the Pavagada population (n=29) and a control group (n=27) without fluorosis, were explored. The ages ranged between 15 and 76 years (mean 50.8 years) were included, and the male to female ratio was 70:30. The severity of dental fluorosis was graded using WHO’s Thylstrup-Fejerskov index (TF), and the concentration of fluoride was determined by a fluoride ion selective electrode (ISE). Genomic DNA was extracted using the standard phenol-chloroform method. The rs412777 and rs414408 polymorphism in COL1A2 were genotyped using the Sanger sequence method. Results: Genotype distributions for rs412777 within each group were: AA 41%, AC 51%, and CC 7% for dental fluorosis participants, and AA 56%, AC 46%, and CC 0% for the control participants. Conclusions: The rs412777 and rs414408 polymorphisms in the COL1A2gene showed no significant association between COL1A2 and the occurrence of dental fluorosis amongst this Indian population.

Prevalence of dental fluorosis and treatment needs among 11-14 years old school children in endemic fluoride areas of Haryana, India.

Dental fluorosis is a major endemic oral disease characterized by hypo mineralization of enamel caused due to consumption of water containing high concentration of fluoride during developmental stages of teeth. To assess the prevalence of dental fluorosis among 11-14 years old school children in endemic fluoride areas of Haryana and to find their treatment needs. A cross-sectional study was conducted among 2200 school children in endemic fluoride areas of Haryana (India) for a period of six months. Dental fluorosis was recorded by the Thylstrup-Fejerskov index (TF index) given by Thylstrup A, Fejerskov O. Data entry and analysis were performed using Statistical Package of Social Sciences (SPSS) software version 18.0. Chi square test was used to find association between TFI scores and gender, age categories. The level of significance was set at 0.05. Prevalence of dental fluorosis (TFI) reached 96.6% with most children falling in TFI score 2, 3, 4 and 5 categories. Mean TFI score of study population was found to be 3.19 ± 1.551. There was significant difference found between gender and prevalence of dental fluorosis (P = 0.00). Our findings showed the increased prevalence of dental fluorosis in endemic fluoride areas with mild to moderate level of dental fluorosis.

Development of a new approach to diagnosis of the early fluorosis forms by means of FTIR and Raman microspectroscopy

This study is aimed at investigating the features of mineralization of the enamel apatite at initial stages of fluorosis development. Samples of teeth with intact and fluorotic enamel in an early stage of the disease development (Thylstrup–Fejerskov Index = 1–3) were studied by Raman scattering and FTIR using Infrared Microspectroscopy beamline at Australian Synchrotron equipment. Based on the data obtained by optical microspectroscopy and calculation of the coefficient R [A-type/B-type], which represents the ratio of carbonation fraction of CO32−, replacing phosphate or hydroxyl radicals in the enamel apatite lattice, the features of mineralization of enamel apatite in the initial stages of development of the pathology caused by an increased content of fluorine in the oral cavity were established. Statistical analysis of the data showed significant differences in the mean values of R [A-type/B-type] ratio between the control and experimental groups for surface layers (p < 0.01). The data obtained are potentially significant as benchmarks in the development of a new approach to preventive diagnostics of the development of initial and clinically unregistered stages of human teeth fluorosis, as well as personalized control of the use of fluoride-containing caries-preventive agents.

Impact of dental fluorosis on the oral health related quality of life among 11- to 14-year-old school children in endemic fluoride areas of Haryana (India)

Objective: This study investigates the impact of dental fluorosis on the oral health-related quality of life (OHRQoL) among 11- to 14-year-old school children in endemic fluoride areas of Haryana (India). Materials and methods: A cross-sectional survey was conducted among 2,200 school children in endemic fluoride areas of Haryana. Using cluster random sampling, three districts out of 14 endemic fluoride districts were selected, and children 11–14 years of age were examined. A child perception questionnaire (CPQ11–14) (Hindi version) evaluated the impact of dental fluorosis on OHRQoL. The Thylstrup-Fejerskov index (TFI) was used for assessing dental fluorosis. The data were analysed using SPSS version 18, and non-parametric tests were used to assess the significance. The regression analysis was used to determine the effect of change in CPQ scores with dental fluorosis at P < 0.05. Results: The study participants included 45.3% males and 54.7% females among which mild to moderate level of dental fluorosis was identified with mean mean TFI Scores being 3.19 ± 1.55. Children without dental fluorosis had 1.17 times more odd of percieving their oral health as excellent/good when compared to children with dental fluorosis (P < 0.05). Study subjects with dental fluorosis did not have higher mean CPQ11–14 domain and total scores when compared with subjects without dental fluorosis. Conclusion: It can be concluded that mild dental fluorosis did not affect the OHRQoL of the children in the endemic fluoride areas of Haryana in India.

Micromorphological analysis and bond strength comparison of two adhesives for different degrees of dental fluorosis

The objective of this study was to analyze morphologically the all-etching bonding system and self-etching bonding system for enamel with different degrees of fluorosis and evaluate the bond strength of each system. Teeth that were indicated for extraction owing to orthodontic or periodontal problems were selected. According to Dean’s index and the Thylstrup-Fejerskov index, 180 extracted teeth were divided into three groups of mild, moderate, and severe dental fluorosis (DF), with 60 teeth in each group. The teeth in each group were randomly divided into two subgroups (n = 30), which were then subjected to the all-etching bonding system (Prime & Bond NT) and self-etching bonding system (SE-Bond). Each group of adhesives was used to bond Z350 universal resin (3 M) to the etched dental enamel. Tensile and shear tests were conducted to determine the bond strength. Subsequently, the fractured specimens were investigated using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The Prime & Bond NT was statistically significant for the tensile and shear strength of enamel with mild fluorosis (P < 0.05) but did not exhibit a significant difference for moderate and severe DF (P > 0.05). The SE-Bond was not statistically significant for the tensile and shear strength of mild, moderate, or severe DF (P > 0.05). The SEM and CLSM results reveal that the mild fluorosis enamel crystals were relatively dense, and a small amount of resin remained. The moderate fluorosis enamel crystals were loosely arranged, and the gaps were widened. The severe fluorosis enamel crystals were irregularly arranged. The disorder was aggravated, and the dentinal orifice was exposed by partial enamel exfoliation. The bonding strength of mild fluorosis enamel with the Prime & Bond NT was better than that with the SE-Bond, and cohesive failure was the most common mode of failure. Because there was no difference in the bonding strength of the SE-Bond for different degrees of DF, we recommend the use of the all-etching adhesive system in the clinical treatment of teeth with mild fluorosis.

Marginalization and fluorosis its relationship with dental caries in rural children in Mexico: A cross-sectional study.

Examine the association between marginalization and fluorosis with caries experience in Mexican rural children aged 8-12, in Oaxaca, Mexico. Cross-sectional study of 283 rural schoolchildren selected from two locations with high and medium levels of marginalization where the water fluoride concentration ranged from 2.0 to 2.5 ppm/F. Caries was evaluated using the DMFT index and dental fluorosis with the Thylstrup-Fejerskov Index (TFI). Socioeconomic data were collected from participants' parents, with data on the children's characteristics collected from them via a questionnaire. The prevalence of caries was 72.4% (DMFT ≥1) in the permanent dentition. The prevalence of fluorosis was 98.0% (TFI ≥4=71.4%). 54.8% of the children brushed their teeth two or more times daily. In logistic regression children living in high levels of marginalization were more likely to present caries (OR=2.11, 95% CI 1.13 - 3.93) than children living in medium levels. Children with severe fluorosis (TFI ≥4) (OR=1.93, 95% CI 1.06 - 3.53) were more likely have caries than those with TFI ⟨3. Rural children with a high level of marginalization and fluorosis (TFI ≥4) were more likely to present caries. Poor oral hygiene and low dental service levels were found in both marginalized areas. Populations with medium/high marginalization are more susceptible to caries.

Prevalence of Dental Fluorosis in a City without Fluoridation in its Water Supply: Effect of Sampling

Objective: To determine the prevalence of dental fluorosis in a population not exposed to fluoridated water and to evaluate the effect of the sampling technique on this measurement. Material and Methods: This observational, cross-sectional and quantitative study was conducted in the city of Mariana, Brazil. The participants were selected based on age, so that they had access to fluoridated dentifrice during the formation of the permanent upper teeth. Based on a nominal survey of schoolchildren aged 14 to 19, a probabilistic sample of 304 such children was clinically examined. Dental fluorosis was measured by the Thylstrup-Fejerskov index. The prevalence of fluorosis identified in a previous study, conducted in 2011 in the same city, using the same methodology but employing convenience sampling, was used as a control to compare the effect of the two sampling techniques . Results: The prevalence of dental fluorosis was 3% based on the probabilistic sampling of the subjects. In the previous study, the prevalence of fluorosis was 7% (p<0.05) based on convenience sampling of the same age group. Both studies detected a Thylstrup-Fejerskov fluorosis index value of 1, corresponding to only a mild degree of dental fluorosis . Conclusion: The convenience sampling technique seems to have affected the prevalence of dental fluorosis identified, with a 4% difference between the two studies. The prevalence of dental fluorosis attributed to the use of fluoridated dentifrice in a population not exposed to fluoridation of the water supply was considered low.

Prevalence and perception of dental fluorosis among the school-going children and its impact on academic performance

Aim: The prevalence of dental fluorosis in Southern India has been reported to be on higher side. In Madurai district, Tamil Nadu, the dental fluorosis incidence among 13–15-year-old school children was observed at 87.7%. The aim of the present investigation is to analyze the prevalence of dental fluorosis among 12–14-year-old school-going children and understand its impact on their academic performance. Materials and Methods: A total 693 students from four different schools were screened for dental fluorosis and severity using Thylstrup–Fejerskov index. Students' academic performance, class attendance, awareness about the condition, esthetic perception about dental fluorosis, and friends' attitude toward their teeth were evaluated. Nonparametric Mann–Whitney U and Kruskal–Wallis tests were employed to assess the influence of dental fluorosis presence on the academic performance. Results: Four hundred and thirteen (59.6%) students had dental fluorosis, and the mean number of teeth affected was 4.15 ± 1.70. Significantly (P

The association between the prevalence of dental fluorosis and the socio-economic status and area of residence of 12-year-old students in Uruguay

Objective: This study investigates the association between the prevalence and severity of dental fluorosis, the socio-economic status (SES) and area of residence among 12-year-old schoolchildren in Uruguay.Material and methods: The study was descriptive, cross-sectional, explanatory and observational. Subjects considered eligible were born in 1999 and had their parents’ or guardian’s prior consent. A questionnaire was used to identify SES according to Centro de Investigaciones Económicas Institute on four levels. Dental fluorosis was determined using the Thylstrup–Fejerskov (TF) index.Results: Of the 1544 students examined, 45.0% showed dental fluorosis. A TF index 1–2 was recorded in 29.3% of the subjects, TF 3 in 20.9%, TF 4 in 6.7% and TF 5–9 in 2.1%. In area 1 (the capital Montevideo city), 84.8% of the subjects had dental fluorosis, a value that was significantly higher than in the inland region (area 2, 24.4%) and border departments (area 3, 22.5%) (x2 = 27.92, p < .0001). Students from families with a low socio-economic level showed less prevalence of dental fluorosis than those with a high level (x2 = 14.58, p = .002).Conclusion: Significant differences exist in the prevalence of dental fluorosis in relation to place of residence and socio-economic level.

Tingkat Fluor Dalam Air Minum dan Pengobatan Fluorosis Berdasarkan Indeks Thylstrup Fejerskov

Fluorosis is teeth disorder a kind of enamel hypoplastic that is defect on the enamel that result in changes on the teeth form, it is caused by excessive fluoride intake during tooth development. Fluorosis could discoloration on the enamel that varied from opaque white spots upto brown so that disrupting of the sufferrer dental esthetic. These study aims to trace the literature on fluor content limit in drinking water which can begin the fluorosis. As well as elaborate various types of fluorosis treatment which appropriate with appropriate classification of Thylstrup Fejerskov Index (TFI) on the child's teeth. Writing method have been used was descriptive method. The results of the literature search, limit of the levels of fluoride in drinking water could begin the fluorosis was 1.3 ppm. Classification fluorosis according to Thylstrup Fejerskov Index (TFI) was organized into 10 classes with scores ranging from 0 upto 9 for each grade of enamel change. Score TF 1 upto TF 3 was a kind of mild fluorosis, TF 4 upto TF 6 was moderat fluorosis, and TF 7 upto TF 9 fluorosis was a kind of heavy. Fluorosis treatments that can be used was microabrasion email, bleaching, veneers and jacket crowns as according to the type of fluorosis. Controlling of the fluoride intake for the children under 8 years is very important to prevent fluorosis but if there has been dental fluorosis hence will be needed a treatment to restore the aesthetic and self-confidence in children.

Occurrence of fluorosis in a population living in a high-fluoride groundwater area: Nakuru area in the Central Kenyan Rift Valley.

Endemic fluorosis caused by the consumption of high-fluoride groundwater is a public health problem in Nakuru, in the Kenyan Rift Valley. The present study was carried out during the period January-February 2017 to determine the prevalence and severity of dental fluorosis among patients of two Nakuru healthcare facilities, namely St. Mary's Hospital-Gilgil and Egerton University-Njoro Dental Clinic. The patients consisted of both young and old members of the Nakuru population served with groundwater containing high levels of fluoride ranging from 0.1 to 72mg/l. The Thylstrup-Fejerskov (TF) index was used to estimate the severity of dental fluorosis. Among the patients of St. Mary's Hospital-Gilgil, the prevalence of dental fluorosis was 86% (n = 100), whereby 54% of the patients were found to have mild to moderate dental fluorosis and 32% had severe dental fluorosis. Whereas the prevalence of dental fluorosis in patients below the age of 14years was higher (92%) than in older patients (85.56%), severity was reversed (average TF = 3.77 for older patients; average TF = 2.18 for younger patients). No significant variation in severity and prevalence of dental fluorosis was recorded with respect to both genders of the patients. The dental fluorosis prevalence rate amongst the patients of the Egerton University-Njoro Dental Clinic was found to be 79.49% (n = 73). However, a comparative analysis of the two age groups revealed a much higher prevalence rate of 100% for patients below the age of 14 relative to the older patients (79.49%). While a high number of cases of dental fluorosis from both healthcare facilities were reported in patients residing in Njoro, Nakuru town, Gilgil and Bahati, the fewer cases were from Solai and Rongai. The results seem to suggest a much higher occurrence of dental fluorosis within the younger population group. This implies that rapid population growth and urbanization puts more pressure on public water resources which leads to a strong reliance on fluoride contaminated groundwater and the concomitant increased cases of dental fluorosis. Therefore, there is a need for a change of local government policy to enhance access to safe water and public education on fluorosis in the areas that were under investigation.

Dental fluorosis and a polymorphism in the COL1A2 gene in Mexican children

ObjectiveTo determine the allelic and genotypic frequencies of rs 412777 polymorphism in the Collagen type I alpha 2 chain (COL1A2) gene and the association with the severity of dental fluorosis in children between 6 and 12 years old in the State of San Luis Potosi, Mexico. DesignA cross-sectional study was designed; participants were 230 children from two rural communities of San Luis Potosí. Fluoride in drinking water and urine samples was quantified using a potentiometric method with a selective ion electrode. Dental fluorosis was diagnosed using the Thylstrup-Fejerskov index while the identification of the polymorphism was made by allelic discrimination, using allele-specific probes by real-time Polymerase chain reaction (PCR). Statistical analysis was carried out with Student’s t-test and Chi-square and Odds Ratio (OR). A confidence interval of 95% and a value of p < 0.05 were considered. ResultsThe concentration of fluoride in drinking water was 2.36 ± 0.02 mg/L in Ojo Caliente and 4.56 ± 0.07 mg/L in La Reforma, the concentration of fluoride in urine was 2.05 ± 0.62 mg/L and 2.99 ± 0.99 mg/L respectively. The prevalence of dental fluorosis was 100% and the frequency of alleles was 67% wild-type and 33% mutant allelic, alleles were found in Hardy-Weinberg equilibrium (X2 = 0.33, p = 0.89). The association between the degree of dental fluorosis and the evaluated polymorphism was statistically significant (OR = 7.10, 95% CI = 3.96–12.70, p < 0.05). ConclusionsAn association of rs 412777 polymorphism in the COL1A2 gene with dental fluorosis was found. Therefore, genetic variants represent a relevant risk factor to develop dental fluorosis, as it was proven in this study conducted in Mexican children.

Gene expression of collagen type I alpha 2 and its relationship with dental fluorosis

Objective: To compare the gene expression levels of collagen type I alpha 2 (COL1A2) in children with and without dental fluorosis. Methods: Cross-sectional study involving 92 children between 5 and 12 years of age. Socio-demographic characteristics, the presence of dental fluorosis by means of the Thylstrup-Fejerskov index, and gene expression analysis of COL1A2 in peripheral blood samples by reverse transcription polymerase chain reaction (RT-PCR) assays, were described. For the descriptive analysis, measures of central tendency, dispersion and proportions were used. Differences between the groups (p&lt;0.05) were established by the Student t-test. Results: Mean age was 8.6 (SD=1.9) years, 51.1% were female; 54 children were diagnosed with fluorosis and 38 without fluorosis; prevalence of dental fluorosis was 58.7% (95% CI: 48.4% -68.9%). Gene expression of COL1A2 was statistically significantly lower (p&lt;0.05) in the participants with dental fluorosis. Conclusion: There are differences in the expression levels of the COL1A2 gene among the population under study. Therefore, COL1A2 may be potentially involved in the development of dental fluorosis