The effect of phytosphingosine associated with tooth brushing on color change, surface roughness, and microhardness of dental enamel — an in vitro and in situ study

Abstract

Objective. This study evaluated, in vitro and in situ, the effect of phytosphingosine (PHS) associated with toothbrushing regarding color stability, surface roughness, and microhardness.Methods. Sixty-four specimens of bovine teeth (6x6x2 mm) were separated in 8 groups (n=8): S+TB: PHS (spray) + toothbrushing; TB+S: toothbrushing + PHS (spray); I+TB: PHS (immersion) + toothbrushing; TB+I: toothbrushing + PHS (immersion); TB: toothbrushing; S: PHS spray; I: immersion in PHS solution and Saliva: immersion in saliva. Toothbrushing simulation (Mavtec, Brazil) was performed (356 rpm, 3.8 centimeters course by the toothbrush -Soft Tek) for 1, 7, 15, and 30 days. PHS remained in contact with specimens for 15 minutes. The specimens were evaluated before and after toothbrushing for color alteration (Easy Shade, VITA), surface roughness (Model SJ-201P Mitutoyo), and Knoop microhardness (HMV-2, Shimadzu Corporation). For the in situ analyses, 8 participants were recruited and received an intraoral device with 6 fragments of bovine enamel (6x6x2 mm). The properties evaluated were the same as those of the in vitro study. Participants were randomized following best results of in vitro tested protocols, for 15 days: TB; TB+S; I+TB. Data obtained by in vitro (two-way ANOVA, Tukey, p <.05) and in situ (one-way ANOVA, Tukey, p <.05) studies were analyzed.Results. The in vitro study showed a greater color change was found after 30 days. The greatest differences in surface roughness occurred between the initial value and after 1 day. Regarding microhardness, the highest values occurred after 15 and 30 days, which were similar. The in situ study showed greater color changes for the TB and I + TB, and greater surface roughness changes for TB and a similar increase in microhardness for the PHS protocols, which were higher than TB.Conclusions. Phytosphingosine leads to an increase in performance regarding color stability, surface roughness, and microhardness when applied. In general, the application of PHS after brushing showed a positive impact on its performance. Clinical relevance. Phytosphingosine showed to be interesting to compound prevention formulations in the dentistry eld.Toothbrushing with toothpaste, responsible for removing surface adhered substances, including extrinsic stains and bio lms, could also interfere in the e ciency of any previous treatment. Although strong evidence underlines the long-term protective effects of PHS coatings for at least 16 h after application [5], there is no report of the long-term sustainability of PHS on the enamel after daily toothbrushing. It is envisaged that its sustainability on the enamel surface after toothbrushing is important since the literature demonstrates changes in the surface roughness of the dental substrate by various products used in dentistry, such as toothpaste and oral hygiene solutions [20][21][22][23].Solutions are often applied by immersion or spray to facilitate their use and decrease the amount of solution needed for antimicrobial action [24]. However, for PHS, the ...