Longitudinal studies into the effect of fluoridated milk on artificial caries lesion mineral change using an in-situ model

Nicol, Ailsa Jan (2006) Longitudinal studies into the effect of fluoridated milk on artificial caries lesion mineral change using an in-situ model. PhD thesis, University of Glasgow.

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It has been known since the early part of the twentieth century that fluoride has a beneficial effect on dental caries. It is now recognised this occurs through the action of preventing demineralisation and encouraging remineralisation, with a minor effect of inhibition of the plaque bacteria involved in the caries process. Fluoride can be delivered to the oral cavity in a number of ways, and is commonly found in toothpastes user by a large proportion of the population in developed countries. Since the mid-1970s, the routine use of fluoride toothpastes in such countries has reduced the caries rate significantly (Haugejorden et al., 1997; Newbrun, 1999). However, for children from disadvantaged areas who may have no access to toothbrushes of toothpastes and whose diet is highly cariogenic, additional sources of fluoride may be beneficial. It has been proved clinically, and confirmed in a systematic review of the literature, that increased exposure to fluoride enhances its caries preventive effect (Marinho et al., 2004b). Fluoridated milk has the benefit that it is possible to taget children who would benefit most from it. Milk has excellent nutritional value; after all, it has been recommended by the Scientific Advisory Committee on Nutrition (SACN), which advises the UK Department of Health, as the sole food for infants up to the age of six months. There are a number of research questions still unanswered regarding the use of fluoridated milk, The topic was reviewed on behalf of the World Health Organisation by Stephen et al (1996). They stated that further research was required to determine, for example: the optimum frequency of intake of fluoridated milk; the optimum concentration of fluoride to be added to milk; the optimum age of the child to whom the milk should be given and the optimum time for which fluoridated milk should be provided. Two recent systematic reviews of the literature pertaining to fluoridated milk stated that the evidence regarding the efficacy of fluoridated milk was impossible to determine because of a lack of suitably designed studies (Holm, 2002; Yeung et al.,2005). Finally, much of the research regarding the efficacy of fluoridated milk as a delivery system was obtained prior to the routine use of fluoridated dentifrices. Thus, the evidence for benefits from the concomitant use of fluoridated milk with a fluoridated dentifrice is lacking. One of the mail aims of the work reported in this thesis was to use an in situ model to investigate the effect of milk, with or without the addition of fluoride, on the remineralisation and/or further demineralisation of artificial carious lesions. The design of the study also included investigation of the effect of using a fluoridated dentifrice slurry to simulate toothbrushing twice-daily, in addition to the milk intake. The change in mineral content of artificial enamel lesions, created in human tooth blocks was measured using two techniques, namely QLF and TMR. A specific study determined the repeatability of the new QLF technique. Using a complete denture in situ model, it was possible to place multiple caries lesions at different sites within each subject's oral cavity. The final aim of this work was to compare the response of caries lesions at different sites to exposure to the experimental protocols, and to determine whether the results supported previous work relating to the site-specificity of caries. In the studies described in this thesis, repeatability estimates for the images capture and image analysis parts of the QLF technique were classed as being 'substantial' by the criteria suggested by Shrout (1998). It was demonstrated that the operator (AJN) could achieve levels of consistency similar to operators described as "experienced" in other studies examining the repeatability of QLF. Subjects who used the fluoridated dentifrice slurry to simulate toothbrushing twice daily tended to have a greater increase in the mineral content between pre- and post-protocol measurements than those who did not use the slurry. This finding applied to both QLF and TMR evaluations, and was statistically significant for some, but not all of the measured parameters. These findings demonstrated that, in this study, the positive effect, on lesion mineral content, of mimulating toothbrushing twice daily, was greater than that of the experimental protocols involving fluoridated milk consumption alone.

Item Type: Thesis (PhD)
Qualification Level: Doctoral
Additional Information: Adviser: Lorna Macpherson
Keywords: Dentistry
Date of Award: 2006
Depositing User: Enlighten Team
Unique ID: glathesis:2006-74070
Copyright: Copyright of this thesis is held by the author.
Date Deposited: 23 Sep 2019 15:33
Last Modified: 23 Sep 2019 15:33
URI: https://theses.gla.ac.uk/id/eprint/74070

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