Calibration was accepted if the PPD measurements at baseline and at 48 h were similar to the millimeter level for > 90% of the evaluations. Statistical analysis Descriptive statistics including means, standard deviations and frequency distributions were constructed using a statistical package software program (SPSS 13.0, SPSS Inc. IL, USA). Each subject was assessed as an experimental unit. The sellekchem mean values of the VAS, PI, GI, PPD and GR measurements of the teeth were calculated for each subject. Since DI is a categorical classification, the median DI score of all teeth was used for each subject and the frequency data were determined. The chi-square test (��2) was used to compare the presence of tooth sensitivity, gender distribution and smoking status of the groups.

Comparisons of all of the other parameters were made between the groups using the independent samples t test; P<.05 was accepted as the level of statistical significance. Pearson��s correlation coefficient (r) was used to determine correlations between the VAS parameters. RESULTS In the preliminary screening, a total of 2249 subjects fitted the inclusion criteria and 378 of these were determined as having dental fluorosis (fluorosis group), while 1871 of them had a normal dentition (non-fluorosis group). The comparisons of the fluorosis and non-fluorosis groups regarding the number of subjects and the number of sensitive teeth and the frequencies of TS are presented in Table 1. There was a statistically significant difference between the groups according to the frequency of TS (P<.001 ��2=13.05).

When compared to the non-fluorosis group, the percentage of subjects with TS was significantly higher in the fluorosis group (P<.001). Table 1. The number of subjects, the number of sensitive teeth, the mean number of sensitive teeth and the frequency of tooth sensitivity in the groups. However, although 645 subjects (28.7%) answered the question ��Have you any sensitivity to hot and/or cold foods, cold air, brushing, or sweet and/or sour foods in your teeth in your daily life?�� positively, TS was only found in 122 subjects (5.42%) in the clinical examination, and these were subjected to the sensitivity study. The number of sensitive teeth per subject was higher in the fluorosis group and this difference was statistically significant (P<.001).

There was no statistically significant difference between the groups Entinostat concerning mean VAS values (P>.05). The mean VAS values of the groups are given in Table 2. Table 2. Visual Analog Scale (VAS) values of the groups. There were positive correlations between the mean VAS scores of tactile and cold air stimuli in both the fluorosis group (r=0.424 and P=0.000) and in the non-fluorosis group (r=0.502, P=0.000). The characteristics of the subjects in each of the groups are given in Table 3. Out of all of the subjects, tooth sensitivity was most prevalent in those aged between 30�C39 years old (41 subjects, 33.6%).