Development and evaluation of a low-erosive apple juice drink with Phosphoryl-Oligosaccharides of Calcium

Baseline Specimens of Erosion and Abrasion Studies

The difficulty in obtaining human teeth that are caries-free that have similar environmental exposure, e.g., diet intake and water fluoridation has lead researchers to opt for bovine teeth as a substitute for erosion studies. Bovine mandibular incisors are readily available at abattoirs and often originate from the same region and are likely to consume similar dietary intake. The bovine teeth for erosion or abrasion studies usually undergo specimen preparation to produce a "flat surface" baseline specimen. Among other terms used to define baseline specimens for erosion and abrasion studies include phrases like "optically flat" and "flat and smooth surface." However, these terms might have no quantitative value as it does not justify the actual surface characteristics of the prepared flattened surface. In dentistry, roughness average (Ra) is the most commonly used parameter when reporting the roughness of specimens Reporting Ra alone might not be sufficient as it does not provide information regarding the surface texture as there is no distinction between valleys and peaks, nor does it provide information about the core structure of a material unlike the bearing area curve. The incorporation of Ra and BAP values in baseline specimens has the potential in predicting the wear or lubricating potential of these specimens. Furthermore, standardization of baseline specimens by acknowledging its surface roughness values ensures comparability of erosion and abrasion studies as different specimen preparation technique might influence the outcome or results of research.

Erosive potential of soy-based beverages on dental enamel

BACKGROUND

This study aimed to investigate the erosive potential of soy-based beverages in comparison to fruit juices of the same flavor.

METHODS

Human enamel blocks were randomly divided into 9 groups (n = 8), according to the beverage category (soy or non-soy juices). The initial pH, TA and β at the original pH value were measured in triplicate. The composition of calcium, phosphate and total protein was analyzed using the specific colorimetric method. The fluoride analysis was performed using a selective electrode. The degree of saturation (DS) and the critical pH (CpH) of each beverage with respect to hydroxyapatite (HAp) and fluorapatite (FAp) were calculated using the computational software. Enamel samples were immersed into 67.5 mL of each drink for 120 minutes. Enamel surface loss (ESL) and differences in surface roughness (ΔRa_E-S) were analyzed by a 3D non-contact profilometer.

RESULTS

Non-soy beverages exhibited the lowest pH values (2.93 to 3.40). The highest values of calcium concentration were founded in soy-based formulations. Juices with soy in their composition tend to have high DS when compared with non-soy based beverages (p = .0571). Soy beverages produced less ESL than non-soy beverages (p < .05). ΔRa_E-S was not significantly different between the categories. The ESL and ΔRa_E-S were positively correlated with initial pH and buffering capacity in soy-based beverages. On the other hand, in non-soy beverages, the ESL was negatively correlated with the TA to 7.0 and the fluoride composition whereas the ΔRa_E-S was negatively correlated with the TA to 5.5.

CONCLUSIONS

The erosive potential of soy beverages was lower than non-soy based beverages.

Study on the influence of leucine-rich amelogenin peptide (LRAP) on the remineralization of enamel defects via micro-focus x-ray computed tomography and nanoindentation

Regeneration of severely damaged enamel (e.g. deep demineralized lesions) is currently not possible, because the structural units of enamel crystal construction are removed after its maturation. The aim of this in vitro study was to evaluate the effect of surface impregnation by leucine-rich amelogenin peptide (LRAP) on the remineralization of eroded enamel using micro-focus x-ray computed tomography (µCT). Fifteen bovine enamel blocks were embedded in resin and three zones (sound, demineralization, and remineralization) were defined on each specimen. Lesions were prepared by immersing the samples in demineralization solution for 7 d. The samples were soaked in distilled water or 60 or 120 µg mL(-1) solution of LRAP in water for 30 min. After the surface treatment, specimens were incubated in artificial saliva for either 5 or 10 d at 37 °C. The amount of mineral gain (dΔZ%) and the relative changes in the lesion depth (dLD%), obtained from µCT, were used to evaluate the effect of LRAP on the remineralization of lesions. The effects of LRAP on cross-sectional integrated hardness ΔINH were studied after 10 d using nanoindentation. ANOVA test was used to determine the effect of time and/or LRAP concentration on dΔZ%, dLD% and ΔINH mean values. Tukey's analysis was used for multiple comparison testing (α = 0.05). Analysis of µCT data showed significant effect of time and LRAP concentration on the dΔZ% (p = 0.013, p = 0.003) and the dLD% (p  <  0.001, p = 0.002) mean values. The nanoindentation hardness was significantly improved by 120 µg mL(-1) LRAP (p = 0.02). Also, the peptide treatment affected the mineral distribution throughout the lesion by inhibiting of superficial deposition. This study showed that the treatment of eroded lesions in enamel by LRAP can improve and regulate the pattern of remineralization in vitro.

Possible ways of reducing dental erosive potential of acidic beverages

Frequent consumption of acidic beverages is related to excessive tooth wear, namely dental erosion. Preventive measures may involve reduction or elimination of acidic drink consumption. However, the success of this approach is difficult to achieve as it is highly dependent on patient compliance. Therefore, a practical way of minimizing the erosive potential of popular acidic drinks may be their chemical modification. The aim of this article was to review the different methods of modification and their shortcomings. The available literature demonstrates that the erosive potential of most acidic beverages could be reduced. To date, the effectiveness of soluble calcium salts supplementation is the best established. However, modification can reduce the sensorial quality of the drink and shorten its shelf-life. There is also a need to evaluate the lowest effective and safe dose of the additive.