Dentifrice Fluoride and Abrasivity Interplay on Artificial Caries Lesions

Abstract

Incipient caries lesions on smooth surfaces may be subjected to toothbrushing, potentially leading to remineralization and/or abrasive wear. The interplay of dentifrice abrasivity and fluoride on this process is largely unknown and was investigated on three artificially created lesions with different mineral content/distribution. 120 bovine enamel specimens were randomly allocated to 12 groups (n = 10), resulting from the association of (1) lesion type [methylcellulose acid gel (MeC); carboxymethylcellulose solution (CMC); hydroxyethylcellulose gel (HEC)], (2) slurry abrasive level [low (REA 4/ RDA 69); high (REA 7/RDA 208)], and (3) fluoride concentration [0/275 ppm (14.5 m<smlcap>M</smlcap>) F as NaF]. After lesion creation, specimens were brushed in an automated brushing machine with the test slurries (50 strokes 2×/day). Specimens were kept in artificial saliva in between brushings and overnight. Enamel surface loss (SL) was determined by optical profilometry after lesion creation, 1, 3 and 5 days. Two enamel sections (from baseline and post-brushing areas) were obtained and analyzed microradiographically. Data were analyzed by analysis of variance and Tukey's tests (α = 5%). Brushing with high-abrasive slurry caused more SL than brushing with low-abrasive slurry. For MeC and CMC lesions, fluoride had a protective effect on SL from day 3 on. Furthermore, for MeC and CMC, there was a significant mineral gain in the remaining lesions except when brushed with high-abrasive slurries and 0 ppm F. For HEC, a significant mineral gain took place when low-abrasive slurry was used with fluoride. The tested lesions responded differently to the toothbrushing procedures. Both slurry fluoride content and abrasivity directly impacted SL and mineral gain of enamel caries lesions.

Biofilm sensitivity of sevenStreptococcus mutansstrains to different fluoride levels

“…The main objective of this study was to investigate the effect of different fluoride concentrations, corresponding to different oral-care products, on the metabolic activity and biofilm formation of seven strains of S. mutans . The concentrations tested were based on a 1:3 dilution that has been used previously [19]. …”

“…Additional fluoride levels (100, 50, 25, 12.5, 6.25, 3.13, and 1.56 ppm) were obtained by serial dilution in deionized water. The 1:3 dilution has been used previously to simulate concentrations of oral products when applied in the oral cavity [18,19]. In addition, to represent the recommended fluoride level for caries prevention in drinking water, a 1.0 ppm fluoride concentration was prepared.…”

Nanoparticle‐Based Targeting and Detection of Microcavities

“…The teeth were coated with an acid resistant varnish leaving a 1 mm 2 enamel window on the buccal surface of the crowns of the teeth. The teeth were then immersed in a pH 5.0 demineralization gel containing 0.1 m lactic acid, 4.1 × 10 –3 m CaCl 2 ‐2H 2 O, 8 × 10 –3 m KH 2 PO 4 , and 1% w/v carboxymethylcellulose sodium at 37 °C for 8 d . At the completion of demineralization, the teeth were rinsed with DI‐water before subjection to caries activity testing.…”

Interaction between toothpaste abrasivity and toothbrush filament stiffness on the development of erosive/abrasive lesions in vitro

“…The aim of the present study was to investigate SL of eroded enamel and dentin resulting from the interaction between toothpaste abrasivity and toothbrush filament stiffness using an established 5-day erosion/ abrasion pH-cycling model 11,14 . The often recommended brushing time of 2 minutes per brushing equates to approximately 15 seconds per surface 20 , which was simulated in the present study by brushing each specimen for 15 seconds or 45 strokes per cycle. This equates to a total of 450 brushing strokes for the entire study duration of 5 days (90 strokes/days) and is considerably less than that used in previous in vitro (strokes/days: 450 11 ; 160 13,15 ; 450-1,500 14 ) and in situ (daily brushing duration: 2 minutes 9 ; 1 minutes 10 ) studies on this topic.…”

“…The often recommended brushing time of 2 min per brushing equates to approx. 15 s per surface 20 which was simulated presently as each specimen was brushed for 15 s or 45 strokes per cycle. This equates to a total of 450 brushing strokes for the entire study duration of 5 d (90 strokes/d) and is considerably less than that used in prior in vitro (strokes/d: 450 11 ; 160 13,15 ; 450-1500 14 ) and in situ (daily brushing duration: 2 min 9 ; 1 min 10 ) studies on this topic.…”