[A national survey on dentin hypersensitivity in Chinese urban adults].

OBJECTIVE: To investigate the prevalence of dentin hypersensitivity in Chinese urban adults aged between 20 - 69 years old and the factors related to dentin hypersensitivity. METHODS: The Chinese national survey on dentin hypersensitivity was conducted in 20 - 69 years old adults in six representative cities, Beijing, Shanghai, Guangzhou, Wuhan, Chengdu, and Xi'an in 2008. A multi-stage stratified randomizing sampling method was used. Subjects were recruited from 36 urban survey sites in 6 cities. A structured questionnaire and a clinical examination on dentin hypersensitivity were used in the survey. The dentin hypersensitivity was diagnosed by a subject self-perceived short, sharp pain in response to a blast of cold air from a triple syringe administered to a tooth surface in 1 cm. RESULTS: In total, 7939 twenty to sixty-nine years old subjects completed a structured interview and underwent a clinical examination on dentin hypersensitivity. Among them, 40.7% (3230/7939) of the subjects reported being suffered from teeth sensitivity. When confirmed using a blast of air from a triple syringe and by ruling out other causes of sensitivity, such as caries, the prevalence was 29.7% (2354/7939), and the mean number of sensitive teeth was 1.4. The highest prevalence of dentin hypersensitivity [39.1% (622/1592)] was found in 50 - 59 years old group. The commonest teeth affected were the premolar teeth and the commonest initiating factor was cold drinks. Female, low education level, with gingival recession, attachment loss, and with the history of acidic substances derived from the stomach was related to dentin hypersensitivity. CONCLUSIONS: Dentin hypersensitivity was common in 20 - 69 years old Chinese urban adults. Dental professionals should give further emphasis to it.

[A study of oral health behaviors among 65 to 74 years old people in Shanxi province].

PURPOSE: To assess the oral health behaviors among 65 to 74 years old people in Shanxi province, and provide a base line for oral health service. METHODS: Four hundred and five old people aged from 65 to 74 in Shaanxi province was selected according to the Third National Oral Health Investigation Criteria and the oral health behaviors of them were investigated by questionnaire. SPSS 13.0 software package was used for statistical analysis. RESULTS: Of the participates, 14.3%, 6.6%, 39.5% of old people ate dessert, candy/chocolate, sugar-containing dairy products every day, and 27.5%, 17.0%, 0.7%, 0.5% drank fresh fruit, saccharine, fruit juice, carbonated drinks once daily, respectively. Compared with the rural areas,the proportion of people who drank fresh fruit or ate dessert, sugar-containing dairy products once daily was higher in the urban area (P<0.01). The proportion of people who significantly smoked cigarette, drank alcohol, or drank tea every day was 31.4%, 33.8% and 70.6%, respectively. Smoking and tea consumption were more prevalent in the urban area as well as in males(P<0.01). No difference was found between the prevalence of drinking alcohol in the urban and rural area(P>0.05), but more males drank alcohol than females(P<0.01). 55.8% of people brushed their teeth more than one time a day. Among the investigated people, about 80% never used the toothpick;only 0.7% of them used dental floss;About 30% of the investigated people used fluorine-contained toothpaste, more of them in the urban areas (P<0.01). Fluorine toothpaste usage was 29.1%, significant difference was found between in the urban and rural area (P<0.01), but no significant difference was noted between in males and females(P>0.05). CONCLUSION: Oral health behaviors of 65 to 74 years old people in Shanxi province is irrationality, and needs to be adjusted and improved.

Dental fluorosis in children in areas with fluoride-polluted air, high-fluoride water, and low-fluoride water as well as low-fluoride air: a study of deciduous and permanent teeth in the Shaanxi province, China.

OBJECTIVE: The aim of the study was to assess dental fluorosis (DF) in the deciduous and permanent teeth of children in areas with high-F coal (area A) and high-F water (area C) compared to children from area B, with low-F water and coal. MATERIAL AND METHODS: 596 children were examined. DF was assessed by TF-score. F-content of indoor air, drinking water, coal, tea, rice, and maize was analyzed. RESULTS: F-content of air and coal ranged from 3.2 microg/m(3) and 25.8 mg/kg (area B), 3.8 microg/m(3) and 36.3 mg/kg (area C) to 56.8 microg/m(3) and 713.1 mg/kg (area A). Likewise, mean F-content of water ranged from approximately 0.50 mg/l (areas A and B) to 3.64 mg/l (area C). F-content of tea leaves was similar in all three areas. Maize and rice contained <5 mg F/kg. Prevalence of primary teeth with DF was 49.1%, 2.0%, and 66.8% in areas A, B, and C, respectively. Similarly, DF was found in 96.7% (area A), 19.6% (area B), and 94.4% (area C) of the permanent teeth. Severe fluorosis (TF > or = 5) was found in area A (47.0%) and area C (36.1%) (p<0.01). Early erupting teeth had slightly higher mean TF-scores in area A than in area C. CONCLUSIONS: DF was prevalent in both dentitions in areas A and C. Similarity in percentages of DF may indicate that indoor air with approximately 60 microg F/m(3) and drinking water with 3.6 mg F/L are similarly toxic to developing permanent teeth. The percentage of deciduous teeth with DF was significantly lower in area A compared to area C. Where low-F coal and low-F water were used (area B), approximately 20% of permanent teeth had DF, indicating a relatively low tolerance to fluoride in Chinese children brought up under the present living conditions.

Dental fluorosis and dental caries in permanent teeth: rural schoolchildren in high-fluoride areas in the Shaanxi province, China.

OBJECTIVES: To study the dental fluorosis and caries in the permanent teeth of 12 to 13-year-old children in fluorosis-endemic areas; to assess the relationship between fluorosis and the fluoride content of the drinking water and the relationship between caries and the fluoride content of the water; finally, to analyze the effect of fluoride intake and water stored in clay pots on dental fluorosis. MATERIAL AND METHODS: 477 children were divided into 5 groups (A to E) according to the fluoride concentration of the waters, i.e. by 0.4, 1.0, 1.8, 3.5, and 5.6 mg F/l, respectively. Dental fluorosis was assessed by TF score and caries by the DMF-T index. A questionnaire was used to obtain information about water storage and other information relevant to children's fluoride intake. RESULTS: A positive relationship was found between the mean TF scores and the water fluoride concentration. In groups B and D, the TF score was higher in 13-year-olds than in 12-year-olds. Caries prevalence and mean DMF-T ranged from 2.6% and 0.03 (group E) to 22.1% and 0.38 (group A). Storage of water in clay pots seemed to increase the severity of fluorosis slightly, and to decrease the caries prevalence. CONCLUSIONS: Defluoridation of drinking water, or--alternatively--the provision of low-fluoride water sources, should be given high priority in the examined Shaanxi rural areas. Fluoride concentration of drinking water should be maximum 0.6 mg/l. Storage of water in the local clay pots may increase the severity of dental fluorosis.

[Effect of drinking water change upon the dental fluorosis].

OBJECTIVE: To assess changes in prevalence and degree of dental fluorosis in individuals born before and after the introduction of water with 1.2 mg/L fluoride instead of water with 2.0-10.0 mg/L fluoride previously used in Da Li County in China. METHODS: The students (n = 291) were divided into 2 groups. The dental fluorosis was scored according to Dean's classification. The statistical analysis was performed by t-test and chi(2) tests. RESULTS: The prevalence of dental fluorosis was significantly lower in the group of the students drinking water from the new well (group 1) as compared to the group of the students drinking the old water (group 2), i.e. 48.8% versus 87.2% (P < 0.01). The percentage of moderate to very severe fluorosis was 13.9% and 0 in group 1 as compared to 32.0% and 8.8% in group 2. The fluorosis community index (FCI), defined by Dean, in group 1 and 2 was medium (1.01) and marked (2.12) respectively. CONCLUSIONS: The results showed that: (1) The prevalence of dental fluorosis was significantly lowered by the new source of drinking water. (2) Drinking water, even with 1.2 mg/L fluoride, may cause dental fluorosis during the period of tooth mineralization.