Pop-cola acids and tooth erosion: an in vitro, in vivo, electron-microscopic, and clinical report

Roughness assessment of colored compomers: Results after an erosive-abrasive in vitro cycling test

Background

The present in vitro study aimed to evaluate and compare the surface roughness of a colored compomer and a composite resin, after 15 days of erosive-abrasive cycling.

Material and Methods

The sample included ninety circular specimens, randomly divided (n = 10): G1 Berry, G2 Gold, G3 Pink, G4 Lemon, G5 Blue, G6 Silver, G7 Orange and G8 Green, referring to the different colors of compomer (Twinky Star®, VOCO, Germany) and G9 for composite resin (Z250®, 3M ESPE). The specimens were submerged in artificial saliva and stored at 37°C for 24 hours. After polishing and finishing, the specimens were submitted to initial roughness (R1). Then, the specimens were submerged in an acidic cola-based drink for 1 minute and then exposed to electric toothbrushing for 2 minutes for 15 days. After this period, the final roughness (R2) and the ΔRa were performed. Data were submitted to ANOVA and Tukey's test for intergroup comparison and paired T-test for intragroup comparison (p<0.05).

Results

Among compomers, the green color presented the higher/lower initial and final roughness values (0.94 ± 0.44, 1.35 ± 0.55) with lemon color presenting the most prominent real roughness increase (ΔRa = 0,74) whereas composite resin showed the lower values (0,17 ± 0.06, 0,31 ± 0.15; ΔRa = 0,14).

Conclusions

All compomers, after the erosive-abrasive challenge, presented an increase in roughness values when compared to composite resin with a highlight to green tones. Key words:Compomers, composite resins, surface properties.

Erosive potential of ice tea beverages and kombuchas

OBJECTIVES

Kombuchas and other tea-based beverages are often perceived as healthy products despite the lack of knowledge on their effects on oral health. This in vitro study determined the erosive potential of commercial kombuchas, and ice teas compared to cola drinks.

MATERIALS AND METHODS

The pH and fluoride content of 7 kombuchas and 18 tea drinks were measured with ion-selective electrodes. Calcium dissolution from hydroxyapatite grains was quantified by atomic absorption spectroscopy after beverage exposure. The effect of beverages on the enamel surface was visualized by scanning electron microscopy (SEM). Distilled water, and cola drinks were used as negative and positive controls.

RESULTS

The kombuchas exhibited lower pH values (2.82-3.66) than the ice teas (2.94-4.86), but still higher than the cola drinks (2.48-2.54). The fluoride concentration varied between 0.05 and 0.46 ppm and for 7 beverages the concentration was below the detection limit. The calcium release for kombuchas was 198-746 mg/l, for ice teas 16.1-507 mg/l, and for cola drinks 57.7-71.9 mg/l. Twenty-two beverages had a significantly greater calcium release than the cola drinks (p = .009-.014). The surface etching of the enamel was seen in the SEM analysis after beverage exposure.

CONCLUSIONS

Tea-based beverages have even higher erosive potential than cola drinks. Kombuchas especially, displayed a considerable erosive potential.

Soft drinks and dental erosion during pediatric age: a clinical investigation

BACKGROUND

Dental erosion is an irreversible condition of loss of teeth hard tissues caused by intrinsic or extrinsic acids attack, without bacterial involvement. Common soft drinks have an acid pH and they release hydrogen ions and act as chelating agents, dissolving teeth mineral component. The aim of the study was to investigate the correlation between the consumption of soft drinks in children and the degree of dental erosion.

METHODS

A questionnaire of 15 multiple choice questions was addressed to the parents of the 231 children needing different dental treatments. Responses were compared with the level of dental erosion of their child, that was clinically investigated using the Basic Erosive Wear Examination (BEWE) index.

RESULTS

About 26.8% of subjects fall into a high-risk category of dental erosion while 24.2% in a low risk level. Socioeconomic status and oral hygiene habits are able to affect the degree of dental erosion. Toothpastes containing fluoride have not proved effective in preventing this phenomenon and no significant correlations were found between the type of toothbrush used and its frequency of use.

CONCLUSIONS

It is necessary to apply preventive measures such as information on the processes and causes of erosion, instruction about right home oral hygiene maneuvers and the possible use of specific products, to avoid the development of problems related to severe dental wear.

Vitamin C Improves Dasatinib Concentrations Under Hypochlorhydric Conditions of the Simulated Stomach Duodenum Model

PURPOSE

pH-dependent drug-drug interactions (DDIs) with poorly soluble, weakly basic drugs may lead to clinical implications. Dasatinib is a tyrosine kinase inhibitor with reduced absorption in patients on acid-reducing agents (ARAs). The objective of this study is to investigate the influence of gastric pH on dasatinib supersaturation and determine if vitamin C (L-ascorbic acid) can improve dasatinib concentrations under simulated hypochlorhydric gastric conditions.

METHODS

A dynamic, in vitro, multi-compartment, simulated stomach duodenum (SSD) model mimicking fluid volumes and transfer rates was used to investigate the concentration of BCS class IIb drugs versus time curves. Dasatinib and lamotrigine were explored under normal, fasted, simulated gastric fluids (pH 2) (FaSGF), hypochlorhydric simulated gastric fluids (pH 4.5) (FaSGF_hypo) and FaSGF_hypo with 1000 mg of vitamin C.

RESULTS

Significant supersaturation of dasatinib was observed in the duodenum compartment of the SSD model in FaSGF. A 90% reduction in dasatinib AUC_∞ was observed in FaSGF_hypo. Upon addition of vitamin C to FaSGF_hypo, drug concentrations were restored to those observed in FaSGF. Lamotrigine AUC_∞ in the duodenal compartment were similar in both FaSGF and FaSGF_hypo. The in vitro trends observed for dasatinib and lamotrigine are reflective of the trends observed in vivo in subjects receiving treatment with ARAs.

CONCLUSIONS

The SSD model serves as a good in vitro tool for assessing the effect of pH-dependent DDIs on bioavailability of weakly basic drugs with solubility/ dissolution limited absorption. Vitamin C provides a promising approach for improving bioavailability of poorly soluble, weakly basic drugs in hypochlorhydric patients.

Effect of Three Commonly Consumed Beverages on Surface Roughness of Polished and Glazed Zirconia-Reinforced Lithium Silicate Glass Ceramics

Objectives:

This study aimed to assess the effect of three commonly consumed beverages on surface roughness of polished and glazed zirconia-reinforced lithium silicate (ZLS) glass ceramics.

Materials and Methods:

In this experimental study, 104 rectangular specimens were cut from Vita Suprinity blocks with 2 mm thickness. After ultrasonic cleaning and firing of the specimens, they were finished and polished in two groups. Specimens in the first group were polished using a 2-step polishing kit while the second group specimens were glazed and heated in a porcelain firing oven according to the manufacturer’s instructions. Baseline surface roughness was measured using a profilometer. Specimens in each group were then randomly divided into 4 subgroups (n=13) for immersion in artificial saliva (control group), cola, orange juice and black tea. Surface roughness was measured again and data were analyzed using two-way ANOVA.

Results:

The highest and the lowest mean Ra were found in orange juice and saliva subgroups, respectively in both glazed and polished groups. The Ra values of both polished and glazed groups significantly increased after immersion in orange juice and cola (P<0.05). The polished surfaces showed insignificantly higher surface roughness compared with glazed surfaces (P>0.05).

Conclusion:

Orange juice and cola significantly increased the surface roughness of both polished and glazed ZLS ceramics. Type of surface finishing (polishing versus glazing) had no significant effect on the surface roughness of specimens following immersion in different beverages.

Are grape juices more erosive than orange juices?

AIMS

To evaluate the chemical characteristics of grape and orange juices, and their erosive potential in the decrease of microhardness and the loss of enamel structure.

METHODS

Five grape and orange juices were evaluated for pH, titratable acidity, calcium, phosphate, and fluoride concentration. De-ionised water and Cola soft drink were used as a negative and positive control, respectively. Twelve specimens of bovine enamel were immersed in beverages for 10 min at 37 °C, 3 times/day for 7 days. Erosive potential was quantified using microhardness and loss of enamel structure. Anova One Way, Student's t test, Multiple Regression and Spearman Correlation (p < 0.05) were used to analyse the results.

RESULTS

Powdered grape juice showed the lowest pH (3.18 ± 0.03) and pure grape juice presented the highest titratable acidity (5.48 ± 0.06 mL NaOH/100 mL). Fresh orange juice and soya-based grape juice revealed the lowest calcium (0.77 ± 0.12 mmol/L) and phosphate concentrations (0.35 ± 0.06 mmol/L), respectively. Among juices, powdered orange juice caused the greatest decrease in surface microhardness (SMH) (127.99 ± 40.47 ΔSMH) and grape juice from concentrate caused the greatest loss of enamel structure (13.30 ± 3.56 μm).

CONCLUSIONS

All of the evaluated juices contributed to dental erosion. Grape juices presented greater erosive potential than orange juices. Pure, powdered and concentrated grape juices showed similar loss of enamel structure to the Cola soft drink. The erosive potential of beverages was statistically correlated to pH, titratable acidity, calcium, phosphate and fluoride concentrations.

Vibrational monitor of early demineralization in tooth enamel after in vitro exposure to phosphoridic liquid

The Raman spectroscopic method has been applied to quantitatively assess the in vitro degree of demineralization in healthy human teeth. Based on previous evaluations of Raman selection rules (empowered by an orientation distribution function (ODF) statistical algorithm) and on a newly proposed analysis of phonon density of states (PDOS) for selected vibrational modes of the hexagonal structure of hydroxyapatite, a molecular-scale evaluation of the demineralization process upon in vitro exposure to a highly acidic beverage (i.e., CocaCola™ Classic, pH=2.5) could be obtained. The Raman method proved quite sensitive and spectroscopic features could be directly related to an increase in off-stoichiometry of the enamel surface structure since the very early stage of the demineralization process (i.e., when yet invisible to other conventional analytical techniques). The proposed Raman spectroscopic algorithm might possess some generality for caries risk assessment, allowing a prompt non-contact diagnostic practice in dentistry.

Effect on oral pH changes and taste perception in 10-14-year-old children, after calcium fortification of a fruit juice

AIM

The aim was to determine the effect of calcium fortification of a commercially available mixed-fruit juice on oral pH changes and taste perception in a group of 10 to 14 year-old Indian children.

METHOD

A controlled, blinded, non-randomised clinical trial was adopted, consisting of a sample of 100 healthy children (DMFT <3; age 10-14 years), who were exposed to three test juices one by one [Group A: original fruit juice (control group); Group B: calcium-fortified fruit juice and Group C: calcium + vitamin D fortified fruit juice]. Oral pH, collection of saliva and plaque sampling was undertaken, before and after the juice exposure by each subject at 0, 1, 5, 15, 30 and 45 min. The respective pH was measured with a digital pH meter. For taste perception, a scoring system was used after exposure of the juices to the subjects in a blind manner. The statistical evaluation was done using one-way ANOVA for salivary and plaque pH and Kruskal-Wallis test for buffer capacity and taste perception.

RESULTS

There was a smaller drop in salivary and plaque pH (p < 0.5) and a significant reduction in perceived taste (p < 0.001) by the subjects after calcium modification of fruit juice.

CONCLUSION

The calcium-modified mixed fruit juices was less acidogenic compared with the unfortified juice, and hence will be less cariogenic and erosive towards teeth.

Effect of a common diet and regular beverage on enamel erosion in various temperatures: an in-vitro study

OBJECTIVE

This study compared diet and regular Coca-Cola on enamel erosion in cold and room temperatures.

MATERIALS AND METHODS

Seventy five enamel specimens were prepared and divided into 5 equal groups (N=15) as follows: Group 1: regular beverage at room temperature, Group 2: regular beverage at refri-gerator temperature, Group 3: diet beverage at room and Group 4: diet beverage at refrige-rator temperature. The specimens were immersed in the regular or diet beverage (Coca-Cola, trade mark regd. Khoshgovar Co., Tehran, Iran) at room (20°C) or refrigerator (2°C) temperatures for 20 minutes, 3 times per day for 7 days. Specimens in the control subjects (group 5) were placed in synthetic saliva at room temperature for 7 days. The hardness of specimens was tested using Vickers test under 500 gr loads for 5 seconds. The data were analyzed using two-way ANOVA and Tukey tests.

RESULTS

The mean and standard deviations of micro-hardness values of the studied groups were as follow: G1: 304.26±29.71, G2: 285.53±42.14, G3: 279.06±39.52, G4: 266.80±23.98 and G5: 319± 30.79. There was a significant difference in the beverage type as the main factor (p<0.05), but temperature factor and their interaction effect on enamel hardness showed no significant difference (p>0.05). Tukey tests showed that there were significant differences between control and diet groups as well as regular and diet groups.

CONCLUSION

Diet Coca-Cola is more erosive than the regular type and the temperature of the beverages used had no significant influence on enamel erosion.