Comparison of the Iodide Permeability Test, the Surface Microhardness Test, and Mineral Dissolution of Bovine Enamel following Acid Challenge

Abstract

The relationship among the iodide permeability (Ip) test, the surface microhardness (SMH) test, and enamel demineralization chemically analyzed as mineral loss was investigated using bovine enamel blocks. Demineralization periods of 0 (control) and 5, 15, 30, and 45 min using 0.05 mol/l lactate (pH 4.75) were chosen to approximate the acid challenge occurring during the intraoral enamel demineralization test. Mineral loss (Ca and PO₄) was found to be directly proportional to dissolution time (r = 0.95). Changes (Δ) in Ip and SMH each increased linearly over time (r = 0.58 and 0.64, respectively) and were similarly related to mineral loss (r = 0.60 and 0.65, respectively). The correlation between ΔIp and ΔSMH was 0.55. When longer demineralization periods (60, 120, and 240 min) were included, the correlation between ΔIp and ΔSMH was 0.68. We conclude that both the Ip test and the SMH test can be used as measures of the early stages of enamel dissolution.

Methods for Assessment of Dental Erosion

“…Changes of enamel structure recorded with IPT have also been shown to correlate well with microhardness testing. This was true for severely eroded samples, in which erosions were performed by immersion in lactate (pH 4.75) for a minimum of 60 min [66] [49]. With shorter exposure periods in the erosive solution, the two methods did not correlate well in this study.…”

“…Note that in contrast to TMR, as is usually applied in caries research, the erosion is performed on the cut sur-face of an already prepared tooth slice of 100-200 tJm thickness rather than on a specimen's surface that is cut perpendicularly for TMR after an experimental procedure. Hall et al [86] [65] found a strong correlation between mineral loss determined by either TMR or profilometry even for discrimination of early ero-sive lesions caused by erosion times of less than 1 h. Another approach to use TMR for erosive mineral loss determination also depends on the use of reference areas not subjected to an erosive challenge [87] [88] [66]. The erosive challenge is executed on a specimens' surface.…”

Effects of enamel abrasion, salivary pellicle, and measurement angle on the optical assessment of dental erosion

“…17 Analysis of calcium ion release from enamel tissues after demineralization cycles was used as a well-accepted method for the assessment of erosion progression. 25,30 In contrast to the reflection analysis, no statistically significant differences were found in calcium dissolution among all groups at all applied erosion times [ Fig. 7(b)] except enamel samples remineralized in human saliva (group 2) and mineral solution (group 4) after a total of 8 min of erosion (Table 3).…”

“…Thus, all prepared specimens had a flat ground enamel area with a 200 μm cut off layer. Samples were stored in a mineral solution (1.5 mmol∕l CaCl 2 , 1.0 mmol∕l KH 2 PO 4 , 50 mmol∕l NaCl, pH ¼ 7.0) 25 and underwent further polishing with a 1 μm diamond abrasive (60 s, LaboPol-6, DP-Mol Polishing, DP-Stick HQ, Struers, Copenhagen, Denmark) immediately before the experiment.…”

Capacidade de dissolução do hipoclorito de sódio e da clorexidina sobre biofilme oral formado 'in situ'

“…As vantagens e desvantagens do uso de modelos experimentais in situ PASTER et al, 2006;PREZA et al, 2008 MELLBERG, 1981;;ZERO et al, 1990;TENUTA et al, 2003;PAES LEME et al, 2004;PIN et al, 2005;MARTINHON et al, 2006) Adicionalmente, no presente estudo, foi utilizada dentina bovina devido a sua grande similaridade com a dentina humana (NAKAMICHI; IWAKU; FUSAYAMA, 1983). Embora, o numero e diâmetro dos túbulos dentinários seja significantemente maior na dentina bovina em comparação com a dentina humana (SCHILKE et al, 2000), este fator não foi relevante neste estudo, pela razão que foi estudada a formação de biofilme oral na superfície dentinária e não a penetração bacteriana intratubular.…”