Surface analysis on primary teeth after using of two toothpastes with different fluoride concentration: an in vivo study

BACKGROUND: The aim of the study was to observe in vivo the surface effect of two different toothpastes, available on the market, with different fluorine concentration. The analysis was conducted in vivo on deciduous teeth. METHODS: A selection of 20 deciduous molars, from 20 patients, was prepared. The selected teeth showed no alteration of the enamel. The teeth were extracted as a result of orthodontic treatments or physiological replacements. The procedures were performed at the UOC of Pediatric dentistry Sapienza University of Rome department of Oral and Maxillo-Facial Science. The selected patients was successively divided in two groups of ten patients each one respectively. The daily oral hygiene procedures was carried out with 500 ppm of fluorine, for the first Group and 1400 ppm of fluorine for the second Group. After 15 days the aforementioned primary teeth were extracted and preserved in normal saline. Successively the primary teeth were sectioned at a cementum-enamel junction and were viewed with VP-SEM electronic microscope to analyze the characteristics of the enamel surface. RESULTS: Micrographic analysis of the samples treated with toothpaste at 500 ppm of fluorine shows non-uniform layers, with a high surface roughness and the presence of irregularly scattered amorphous precipitates. Patient samples that instead used toothpaste with a fluoride concentration of 1400 ppm, show a less irregular surface with a present, but more attenuated, roughness. A finer granulation than the previous ones is visible in an uneven manner, which confers a non-uniform but in any case more structured stratification.CONCLUSIONS: In the pediatric field the prevention of caries lesions is one of the main targets. Early remineralization of initial enamel alterations may result in a delay in the progression of the carious process and an arrest of the same. The use of toothpaste with a high content of fluorine showed a better remineralizing effect, resulting in a more uniform surface compared to teeth after toothpaste treatment with 500 ppm fluorine. These do not improve the superficial morphology of the teeth, maintaining a relevant roughness that exposes the enamel more to the bacterial insult and the onset of carious lesions.