Izvorni znanstveni članak
Alterations in enamel microhardness in initial carious lesions
Tonči Staničić
; Zavod za dentalnu patologjiu Stomatološkog fakulteta u Zagrebu, Zagreb, Hrvatska
Krešimir Novosel
; Zavod za m aterijale Strojarskog fakulteta u Zagrebu, Zagreb, Hrvatska
Sažetak
Intact enamel of 18 permanent impacted third lower molars that had
not come into contact with oral cariogenic factors prior to extraction,
was used to study the initial development of carious enamel destruction in an in vivo experiment. Four specimens of each tooth enamel were inserted into the volunteers’ partial prostheses, whereas the fifth specimen served as a control. The specimens were left in the volunteers’ mouths for 7, 14, 21 or 28 days. After removing them out the prostheses, the specimens were cieaned from organic deposits, embedded into epoxy resin and polished with diamond powder. The measurement of microhardness along the specimen cross-sections according to Vicekrs was employed to assess the extent of the processes of demineralization and remineralization during the development of initial caries. The first results pointing to changes in microhardness were obtained only in the specimens that were left in mouths for 21 days, involving the first 30 μm of the enamel surface. This did not exclude the process of demineralization as being also present in the specimens orally exposed during a shorter period of time, but showed the method of evaluation chosen to be inadequately precise to record it at this stage of the development of caries. Stronger demineralization was recorded to the depth of 60 μm in the
specimens orally exposed during 28 days. In four specimens from the latter group, the value of microhardness was obesrved to increase in the superficial 30 μm, which would indicate the process of remineralization, but this increase did not reach the values of microhardness of the original intact enamel of the respective tooth control samples.
Ključne riječi
Hrčak ID:
102634
URI
Datum izdavanja:
15.6.1988.
Posjeta: 1.474 *