Re- and Demineralization Characteristics of Enamel Depending on Baseline Mineral Loss and Lesion Depth in situ

Abstract

Objectives: The aim of this double-blinded, randomized, cross-over in situ study was to evaluate the re- and demineralization characteristics of sound enamel as well as lowly and highly demineralized caries-like enamel lesions after the application of different fluoride compounds. Methods: In each of three experimental legs of 4 weeks, 21 participants wore intraoral mandibular appliances containing 4 bovine enamel specimens (2 lowly and 2 highly demineralized). Each specimen included one sound enamel and either one lowly demineralized (7 days, pH 4.95) or one highly demineralized (21 days, pH 4.95) lesion, and was positioned 1 mm below the acrylic under a plastic mesh. The three randomly allocated treatments (application only) included the following dentifrices: (1) 1,100 ppm F as NaF, (2) 1,100 ppm F as SnF₂ and (3) 0 ppm F (fluoride-free) as negative control. Differences in integrated mineral loss (ΔΔZ) and lesion depth (ΔLD) were calculated between values before and after the in situ period using transversal microradiography. Results: Of the 21 participants, 6 did not complete the study and 2 were excluded due to protocol violation. Irrespectively of the treatment, higher baseline mineral loss and lesion depth led to a less pronounced change in mineral loss and lesion depth. Except for ΔΔZ of the dentifrice with 0 ppm F, sound surfaces showed significantly higher ΔΔZ and ΔLD values compared with lowly and highly demineralized lesions (p < 0.05, t test). Conclusion: Re- and demineralization characteristics of enamel depended directly on baseline mineral loss and lesion depth. Treatment groups should therefore be well balanced with respect to baseline mineral loss and lesion depth.

Effects of Self-Assembling Peptide P11-4, Fluorides, and Caries Infiltration on Artificial Enamel Caries Lesions in vitro

“…Although the lesion depths of the specimens in the present study can be considered as deep when compared with lesion depths used in recent in vitro and in situ studies [Meyer-Lueckel et al, 2015a;Souza et al, 2015;Wierichs et al, 2016Wierichs et al, , 2017, the lesions can be considered "subclinical" from a clinical point of view. Some of them would probably even be difficult to detect in vivo [ten Cate et al, 2008].…”

The influence of hardness and chemical composition on enamel demineralization and subsequent remineralization

“…Fluoride, even in concentrations available in over-the-counter toothpastes, can enhance remineralization of lesions and form a highly mineralized surface layer in initially demineralized enamel and dentin specimens [14,[32][33][34]. The maximum mineral density of the surface layer in the tested groups exhibited greater mineralization in the presence of fluoride than in its absence [35]. In the presence of fluoride, further dissolution is prevented as a result of re-precipitation of the dissolved minerals in the form of a fluoride-rich surface layer.…”

Caries-Preventive Effect of NaF, NaF plus TCP, NaF plus CPP-ACP, and SDF Varnishes on Sound Dentin and Artificial Dentin Caries in vitro

“…The roots were cleaned and 400 dentin blocks (5 × 3.5 × 3 mm) were prepared (Exakt 300; Exakt Apparatebau, Norderstedt, Germany) [Wierichs et al, 2016] (Fig. 1).…”