Quantification of dental fluorosis using fluorescence imaging.

Fluorescence imaging hardware and software have been recently employed to assess demineralization due to early dental caries. Dental fluorosis also presents as diffuse surface hypomineralization of enamel and in principle similar measurement methods might be applicable to both. The caries analysis system requires the user to select an area of sound enamel around the lesion so that the affected surface can be reconstructed and the lesion subtracted. Whereas early caries presents as discrete isolated lesions fluorosis is characterized by diffuse opacities covering most of the tooth. Consequently it is difficult to use commercial QLF software for the assessment of fluorosis, as there is typically no sound area of enamel to use for reconstruction. This study describes a fluorescent imaging device capable of recording digital images of the anterior teeth and also software that is able to objectively measure fluorosis area and severity. A convenience sample of 26 subjects with a range of fluorosis from TF scores 0-3 took part in the study. The upper left central incisor of these subjects was scored for fluorosis using the TF index, photographed using a conventional digital camera and imaged using the fluorescence imaging device. The TF index was then used to visually score the digital photographs and the fluorescence images. The data from the fluorescence method demonstrated a strong correlation with TF scores from fluorescence images (Kendall's tau = 0.862). The fluorescence imaging method shows promise as an objective, potentially blinded system for the longitudinal assessment of enamel fluorosis in vivo.

The prevalence and severity of fluorosis in children who received toothpaste containing either 440 or 1,450 ppm F from the age of 12 months in deprived and less deprived communities.

This study compared fluorosis in the upper central incisors of children from socially diverse backgrounds who had received either 440- or 1,450-ppm F toothpaste from 12 months of age. The children were resident in non-fluoridated districts in the north-west of England. They received either 440- or 1,450-ppm F toothpaste and advice regarding its use until the age of 5-6 years. Dental fluorosis (TF index) was assessed on digital images of dried teeth when the children (n = 1,268) were 8-10 years old. In the less deprived districts the prevalences of fluorosis (TF >or=0) for the 1,450- and 440-ppm F groups were 34.5 and 23.7% (p = 0.006). In the deprived districts the prevalences of fluorosis were 25.2 and 19.5% (p = 0.2). Overall the prevalences of TF >or=2 were 7 and 2.1% for the 1,450- and 440-ppm F groups and 2.2 and 0.2% for TF >or=3. These differences were statistically significant (p < 0.003). There was a strong association between the deprivation status of wards and fluorosis. Only 1 subject with a TF score of 3 was identified in the two most deprived quintiles of the Townsend score. It is concluded that careful targeting of programmes of this type to children living in high caries risk deprived communities carries only a small risk of aesthetically objectionable fluorosis (TF >2) whether low or high fluoride toothpastes are used. High fluoride (1,450 ppm F) toothpastes should not be provided on a community basis to very young children in less deprived communities.

The prevalence and severity of fluorosis and other developmental defects of enamel in children who received free fluoride toothpaste containing either 440 or 1450 ppm F from the age of 12 months.

OBJECTIVE: To assess the impact of a programme regularly supplying free fluoride toothpaste to children on the prevalence and severity of fluorosis and other developmental defects of enamel. DESIGN: Randomised, controlled, parallel three-group clinical trial. Two groups received toothpaste containing either 440 or 1450 ppm F; the third group received no intervention. Children were supplied with toothpaste and advice on its use from the age of 12 months until they were 5-6 years old. The participants were a sub sample of those involved in a study that considered the caries benefits of providing free fluoride toothpaste. They were eligible if they completed the main study, lived in four of the nine districts involved and attended schools with 6 or more eligible participants. SETTING: Children from the north west of England consuming drinking water containing less than 0.1 ppm F were examined in primary schools. PARTICIPANTS: 3731 children completed the main study. Of the 1833 children in the four selected districts, 927 were from schools with six or more participants. METHOD: Digital images encompassing the upper and lower anterior sextants were taken of each child when they were 8-9 years old. MAIN OUTCOME MEASURES: Developmental defects of enamel and dental fluorosis (TF index) were recorded on upper central incisors from wet and dry images. RESULTS: A total of 703 children were included in the data analysis. In the 1450 ppm F (n=218), 440 ppm F (n = 226) and control (n = 259) groups the prevalence of dental fluorosis (TF > 0) was 17%, 15% and 12% for the wet (p > 0.05) and 26%, 24% and 25% for the dry (p > 0.05) photographs respectively. The prevalence of TF scores 2 or 3 (highest score) was 5%, 4% and 2% and for the wet (p > 0.05) and 7%, 4% and 5% for the dry (p > 0.05) photographs respectively. All subjects identified with TF score 3 were found in the group using the 1450 ppm F toothpaste (3 wet and 4 dry) and there were statistically significant differences between the three groups for both wet (p = 0.03) and dry photographs (p < 0.01). However, the pairwise comparisons between the groups failed to attain statistical significance. The highest prevalence and severity of demarcated opacities was seen in the control group and for the wet photographs the difference between the three groups attained statistical significance (p = 0.04). For both the wet and dry photographs the prevalence of any enamel defects (including fluorosis) and large demarcated or TF score 3 was similar for the three groups (p > 0.05). CONCLUSION: Previously it has been reported that only the provision of 1450 ppm F toothpaste provides anticaries benefits in a programme of this type. This benefit is accompanied by a slight increase in prevalence of TF score 3 but not the overall prevalence of developmental defects of enamel. Careful targeting and implementation of a programme of this type is required to maximise benefits and minimise risks of fluoride exposure.