In vitro Remineralization of in vivo and in vitro Formed Enamel Lesions

Abstract

Thin sections of natural white spot enamel lesions (WS) and of artificial in vitro lesions (VL) were remineralized simultaneously in vitro. The sections, clamped in a PMMA holder, were microradiographed at baseline and after remineralization in a calcium– and phosphate–containing solution (pH = 7.0; 1 ppm F) after 2 and 4 weeks. All data were analyzed with respect to baseline. The results show that the lesion depth values did not change significantly during 2 and 4 weeks of remineralization. The mineral accumulation (change in ΔZ), however, was substantial and significant in WS and VL. In WS the change in mineral accumulation was roughly proportional to the amount of mineral at baseline. The WS accumulated more than two times the amount of mineral than VL in the same periods of remineralization. After 4 weeks of remineralization the maximum mineral value V_max in the surface layer of the WS was nearly up to the sound enamel level ≈87 vol%. This study shows that the technique and calculation procedure described make this single section method attractive for longitudinal demineralization–remineralization studies in vitro or in situ. Both WS and VL samples obviously remineralized in vitro similarly with respect to the baseline. Furthermore, this in vitro work indicates that remineralization inhibitors present in saliva, and previously penetrated into the enamel tissue, do not influence remineralization later on.

Sucrose substitutes and their role in caries prevention

“…** Side effects when taken in excess are abdominal discomfort, flatulence, softened stools, and diarrhea. • In vitro models 22,23 • Animal models [24][25][26][27][28] • In vivo monitoring of acid production by human dental plaque bacteria using indwelling pH sensor (human plaque pH method) 10,11,[29][30][31] • Intraoral cariogenicity tests or demineralisation/remineralisation models 32,33 . At present, all four of the above examinations are required to evaluate the cariogenicity of an individual sugar substitute.…”

“…However, these effects are not unique to xylitol [32][33][34]42,54 . In fact, the inhibitory effect of xylitol on the growth of mutans streptococci is rather weak, and the remineralisation activity is common to all sugar alcohols.…”

Chemical alteration by tooth bleaching of human salivary proteins that infiltrated subsurface enamel lesions —Experimental study with bovine lesion model systems—

“…Even under circumstances favorable for remineralization in vivo, early carious lesions may fail to achieve remineralization. The proteins in human saliva, such as statherin, a tyrosine-rich acidic peptide, acidic proline-rich phosphoproteins (PRPs), or albumin, may hinder remineralization by infiltrating into the lesions [4][5][6] . The involvement of such proteins, however, remains unclear because of the lack of any appropriate assay system.…”

Comparison of the newer preventive therapies on remineralisation of enamel in vitro

“…Subsequently, a great number of in situ and in vitro investigations were conducted in the following decades and showed that remineralisation occurs in newly formed artificial enamel lesions (Mellberg et al, 1986, Dijkman et al, 1990, Manning and Edgar, 1992, as well as in lesions formed under plaque in situ (Dijkman et al, 1986) and in vivo (Øgaard et al, 1988). With regard to the baseline mineral loss, it has been shown that the remineralisation of newly formed white spot lesions and in vitro formed lesions take place in the same way (Iijima et al, 1999).…”