Estimated erosive potential depends on exposure time

Examining enamel-surface demineralization upon exposure to acidic solutions and the remineralization potential of milk and artificial saliva

The enamel surface may undergo demineralization due to exposure to acidic substances and the remineralization of the etched enamel is crucial to regain or maintain integrity. This study aimed to investigate the erosive effect of 10 acidic solutions on tooth enamel and the remineralization capacity of milk and artificial saliva by measuring surface roughness (Ra), enamel depth, and microhardness. A total of 80 bovine incisor enamel specimens were immersed in 10 different acidic solutions, including four different acidic drinks, three different citric acid solutions, and three different citric acid buffer solutions, for 1 h. After demineralization, the specimens were immersed in milk and artificial saliva for 3 h. Surface roughness, enamel abraded depth, and microhardness were measured before demineralization, in-between time intervals and after remineralization. Data were analyzed using Friedman and Kruskal-Wallis tests (p < 0.05). The results indicate a significant difference in surface roughness between the measurements taken at different time intervals, particularly between the baseline and after 1 h demineralization. Also, the specimens immersed in CAB1 exhibited greatest increase in Ra among other acidic solutions (Δ: 0.18 ± 0.07). Moreover, only the microhardness increased after remineralization (p < 0.05). Enamel demineralization using various acidic solutions revealed increased Ra and enamel abraded depth, and decreased microhardness. The use of remineralization agents, milk and artificial saliva, demonstrated an increase in microhardness. This study provides insights into the effects of different acidic solutions and potential remineralization agents on tooth enamel.

Influence of energy drinks on enamel erosion: In vitro study using different assessment techniques

Background

Dental erosion has become a relevant public health problem in recent years and is related to the increase in the consumption of acidic beverages. Objective: The aim of the present study was to evaluate the erosive potential of energy drinks on dental enamel using an in vitro erosion model.

Material and Methods

Thirty-eight blocks of human enamel were divided into four groups: G1- TNT Energy Drink®(n=8), G2- Red Bull® (n=10), G3- Monster Energy® (n=10), and G4- Coca-Cola® (n=10) (positive control). For the chemical analysis, the pH values, titratable acidity, and buffering capacity of the beverages were measured in triplicate. For the erosive test, the specimens were immersed in the beverages (5ml/block) for 30 minutes at room temperature with gentle shaking. Initial and final surface microhardness values were measured and the percentage of the loss of surface microhardness was calculated. Profilometry (surface loss and lesion depth) and mineral loss analysis (quantitative light-induced fluorescence) were performed. The data were analysed statistically using ANOVA followed by the Bonferroni correction, Pearson’s correlation test, and multiple linear regression (p<0.05).

Results

The energy drinks had pH values ranging from 2.36 to 3.41. The lowest titratable acidity value was recorded for Monster Energy® and the highest was recorded for TNT Energy Drink®. All energy drinks had buffering capacity values higher than Coca-Cola®. Analysing the eroded enamel surface, the specimens submitted to TNT Energy Drink® had the greatest percentage loss of surface microhardness, surface loss, depth, and mineral loss, followed by those submitted to Red Bull® and Monster Energy®. Surface loss was the only predictor of mineral loss (p<0.001).

Conclusions

Based on the study model employed, all the energy drinks examined were erosive to tooth enamel and TNT Energy Drink® had the worst behaviour.

Key words:Energy drinks, tooth erosion, tooth demineralisation, hardness tests, quantitative light-induced fluorescence.

Methodology to Quantify and Screen the Demineralization of Teeth by Immersing Them in Acidic Drinks (Orange Juice, Coca-Cola™, and Grape Juice): Evaluation by ICP OES

Oral health problems may occur as a result of the ingestion of acid drinks. The objective of this in vitro study was to quantify and screen the concentration of potassium (K), phosphorus (P), calcium (Ca), magnesium (Mg), manganese (Mn), zinc (Zn), iron (Fe), copper (Cu), barium (Ba), lead (Pb), arsenic (As), cadmium (Cd), aluminum (Al), cobalt (Co), chromium (Cr), molybdenum (Mo), sodium (Na), nickel (Ni), selenium (Se), and vanadium (V) released from bovine incisors during an erosive challenge at different times of exposure when immersed in Coca-Cola™, orange juice, and grape juice. A total of 240 samples of bovine incisor teeth were used for the erosive challenge and allocated in groups. Digestion of drinks was performed using microwave-assisted digestion. The content in acidic drinks was monitored before and after the erosive challenge at exposure times of 1, 5, and 60 min using inductively coupled plasma optical emission spectrometry (ICP OES). The drinks’ pH varied slightly during the erosive challenge but remained below the critical value of pH 5 to cause tooth demineralization. The concentrations of elements released from the bovine incisors during the in vitro erosive challenge depend on exposure times when immersed in acidic beverages. For some elements such as Ca, Mn, Zn, Fe, Cu, Ba, Pb, As, and Cd, quantified in acidic drinks, grape juice had greater erosive potential than Coca-Cola™ and orange juice. Quantification and monitoring of chemical elements in bovine teeth can be performed considering a longer erosive time and other types of acidic drinks. Further analysis using human teeth is still not available and must be conducted. The demineralization of teeth not only occurs in acidic beverages; physical and chemical factors play other roles and should be investigated.

Enhancement in Xerostomia Patient Salivary Lubrication Using a Mucoadhesive

Oral lubrication mediated by mucin and protein containing salivary conditioning films (SCFs) with strong water retainability can get impaired due to disease such as xerostomia, that is, a subjective dry mouth feel associated with the changed salivary composition and low salivary flow rate. Aberrant SCFs in xerostomia patient cause difficulties in speech, mastication, and dental erosion while the prescribed artificial saliva is inadequate to solve the complications on a lasting basis. With the growing aging population, it is urgently needed to propose a new strategy to restore oral lubrication. Existing saliva substitutes often overwhelm the aberrant SCFs, generating inadequate relief. Here we demonstrated that the function of aberrant SCFs in a patient with Sjögren syndrome can be boosted through mucin recruitment by a simple mucoadhesive, chitosan-catechol (Chi-C). Chi-C with different conjugation degrees (Chi-C7.6%, Chi-C14.5%, Chi-C22.4%) was obtained by carbodiimide chemistry, which induced a layered structure composed of a rigid bottom and a soft secondary SCF (S-SCF) after reflow of saliva. The higher conjugation degree of Chi-C generates a higher glycosylated S-SCF by mucin recruitment and a lower friction in vitro. The layered S-SCF extends the "relief period" for Sjögren patient saliva over 7-fold, measured on an ex vivo tongue-enamel friction system. Besides lubrication, Chi-C-treated S-SCF reduces dental erosion depths from 125 to 70 μm. Chi-C shows antimicrobial activity against Streptococcus mutans. This research provides a new key insight in restoring the functionality of conditioning film at articulating tissues in living systems.

In vitro assessment of erosive effects of some common soft drinks on dental hard tissues

Background/Aim: The chemical nature of soft drinks is acidic, so they possess the capacity to cause hard tissue erosion. The aim of this study is to assess the potentially erosive effect linked to pH and titratable acidity of some common soft drinks on dental hard tissues in prolonged time exposure. Material and Methods: Seven types of soft drinks in Romanian market were selected for this study. The pH and Titratable acidity were determined. Twenty one human dental hard tissue specimens were immersed in 5 ml solution each for 336h. Every 48h weight loss was determined for each specimen and after 336h volume changes were calculated. Enamel microhardness was determined using a Microhardness Tester model HV-1000 and compared to normal enamel microhardness. Results: The pH values of beverages ranged from 2.37 to 3.1, showing no significant differences. All specimens presented color and surface texture modifications, weight loss and volume reduction. There were found significant differences between the mean values of weight loss and enamel microhardness of each type of specimens and type of beverages tested. The most representative findings were achieved by indentations done in specific zones on Sprite® immersed specimen. This result suggest that microhardness near the eroded surface was significant lower than in other zones. Conclusions: Data obtained have shown that all the soft drinks tested had an erosive effect, causing dental hard tissue dissolution. For prolonged time exposure titratable acidity may be a major predictor for erosive potential. Dental erosion may affect different levels of enamel causing decreased enamel microhardness.

Dissolution of Enamel on Exposure to Various Commercial Beverages Available in India

AIM

The study was aimed to estimate the pH of the commonly available soft drinks in the Indian market and to assess the detrimental effects of the juices and beverages on the tooth surface by measuring the weight loss of the tooth sample.

MATERIALS AND METHODS

The study was done with eight different types of commercially available carbonated drink and fruit juices available in the Indian market among which six were carbonated drinks and two were juices. Carbonated drinks experimented were Coca-Cola, Pepsi, Fanta, Mirinda, 7Up and Sprite, and two fruit juices were Tropicana orange juice and real orange juice. Ten different bottles from each category were obtained, and the pH was estimated. Each of the beverages was divided into batch of 10 containers containing the tooth sample. Weight of all samples was measured at 24, 48, 72, 96, and 120 hours with subsequently changing each solution at an interval of 24 hours.

RESULTS

The mean pH of the beverages was found ranging from 2.13 ± 0.02 in Pepsi to 3.41 ± 0.02 in Tropicana on opening. The mean pH of water was found to be 6.98 ± 0.01. Among carbonated drinks, the mean weight loss after 24 hours was highest in Coca-Cola and least in 7Up. Tropicana fruit juice had a higher tooth loss than real orange juices. When compared with water, the tooth loss was significantly higher in Coca-Cola after all specified time (hours).

CONCLUSION

The pH of both carbonated drinks and fruit juices was below the critical pH. The weight loss was also seen after every 24 hours in all the carbonated drinks and beverages. The study showed that these commercial beverages are harmful to the tooth structures, and hence, the health professionals play a major role in educating the population about its effects and advising them to use these products precisely.

CLINICAL SIGNIFICANCE

The change in lifestyle has increased the demand of soft drinks and artificial juice in Indian market. The use of these carbonated drinks and fruit juices causes damage to the tooth structure in all ages, especially in young mass. Our study provides an idea about the deleterious effects of these commercial drinks on dental hard tissues.

Protective effects of a zinc-hydroxyapatite toothpaste on enamel erosion: SEM study

AIM

The aim of the present in vitro study was to evaluate the protective effects of a zinc-hydroxyapatite toothpaste against an erosive challenge produced by a soft drink (Coca-Cola) using Scanning Electron Microscopy (SEM).

METHODS

Forty specimens were assigned to 4 groups of 10 specimens each (group 1: no erosive challenge, no toothpaste treatment, group 2: erosive challenge, no toothpaste treatment, group 3: erosive challenge, fluoride toothpaste treatment, group 4: erosive challenge, zinc-hydroxyapatite toothpaste treatment). The surface of each specimen was imaged by SEM. A visual rating system was used to evaluate the condition of the enamel surface; results were analyzed by nonparametric statistical methods.

RESULTS

Statistically significant differences were found between the samples untreated and those immersed in Coca-Cola (group 1, 2); the highest grade of damage was found in group 2, while the lowest grade was recorded in the samples of group 4. Comparing the groups, the two analyzed toothpaste tended to protect in different extend.

CONCLUSIONS

In this study treatment of erosively challenged enamel with Zn-Hap toothpaste showed a clear protective effect. This was greater than the effect observed for a normal fluoride toothpaste and confirmed the potential benefit the Zn-HAP technology can provide in protecting enamel from erosive acid challenges.

A simple, sensitive and non-destructive technique for characterizing bovine dental enamel erosion: attenuated total reflection Fourier transform infrared spectroscopy

Although many techniques are available to assess enamel erosion in vitro, a simple, non-destructive method with sufficient sensitivity for quantifying dental erosion is required. This study characterized the bovine dental enamel erosion induced by various acidic beverages in vitro using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Deionized water (control) and 10 acidic beverages were selected to study erosion, and the pH and neutralizable acidity were measured. Bovine anterior teeth (110) were polished with up to 1 200-grit silicon carbide paper to produce flat enamel surfaces, which were then immersed in 20 mL of the beverages for 30 min at 37 °C. The degree of erosion was evaluated using ATR-FTIR spectroscopy and Vickers' microhardness measurements. The spectra obtained were interpreted in two ways that focused on the ν1, ν3 phosphate contour: the ratio of the height amplitude of ν3 PO4 to that of ν1 PO4 (Method 1) and the shift of the ν3 PO4 peak to a higher wavenumber (Method 2). The percentage changes in microhardness after the erosion treatments were primarily affected by the pH of the immersion media. Regression analyses revealed highly significant correlations between the surface hardness change and the degree of erosion, as detected by ATR-FTIR spectroscopy (P<0.001). Method 1 was the most sensitive to these changes, followed by surface hardness change measurements and Method 2. This study suggests that ATR-FTIR spectroscopy is potentially advantageous over the microhardness test as a simple, non-destructive, sensitive technique for the quantification of enamel erosion.

Microhardness evaluation of silorane and methacrylate composites submitted to erosion and abrasion processes

Objective: The aim of this study was to evaluate the Knoop hardness number (KHN) of methacrylate (MC) and silorane (SC) composites after being submitted to erosion and abrasion processes. Material and methods: Forty samples were made with each composite: MC and SC. The samples were divided into eight groups (n = 10) according to the type of composite (G1-G4, MC; G5-G8, SC) and the beverages involved in the erosion process (G1 and G5 - Control (C), without erosion, with abrasion; G2 and G6 - Orange Juice (OJ), abrasion; G3 and G7 - Smirnoff Ice® (SI), abrasion; G4 and G8 - Gatorade® (GA), abrasion). The KHN test was performed 24 h after the last cycle of erosion/abrasion. Results: The MC groups showed smaller KHN values for the SI group (p < 0.05) when compared to the Control and OJ groups; however, for the SC groups, no differences were found (p > 0.05). Conclusion: Methacrylate composite when submitted to acidic beverages erosive challenge combined with abrasive process might alter its surface microhardness. However, the beverages used in the present study were not able to interfere in silorane composite surface microhardness.

Influence of various acidic beverages on tooth erosion. Evaluation by a new method

MATERIAL & METHODS

We have analyzed the loss of enamel and dentine after exposure to different non-alcoholic drinks with a simple new method using bovine teeth. 100 enamel and 100 dentine specimens from freshly extracted bovine incisors were randomly attributed to 10 groups (n=10 for enamel and dentine each). Prior to the start of the experiment all specimens were weighed using a precision balance. The mean initial masses (SD) were 35.8 mg (7.2) for enamel and 24.7 mg (7.0) for dentine. No statistically significant differences were found between groups for initial masses (p>0.05, ANOVA with Bonferroni post hoc test). Thereafter, all specimens of one group were simultaneously placed in 200 ml of the following fluids: Coca-Cola, Coca-Cola light, Sprite, apple juice, Red Bull, orange juice, Bonaqua Fruits (Mango-Acai), tap water, chlorinated swimming pool water, and lemon juice. Fluids were continuously ventilated at 37° C for 7 days. Thereafter the specimens were weighed again and the mean mass loss was calculated.

RESULTS

The values were (enamel/dentine): Coca-Cola 7.5 mg/6.6 mg; Coca-Cola light 5.2 mg/3.5 mg, Sprite 26.1 mg/17.7 mg, apple juice 27.1 mg/15.2 mg, Red Bull 16.6 mg/17.0 mg, orange juice 24.3 mg/20.2 mg, Bonaqua Fruits (Mango-Acai) 17.8 mg/16.2 mg, tap water -0.2 mg/-0.3 mg, swimming pool water -0.3 mg/-0.2 mg, and lemon juice 32.0 mg/28.3 mg. From all drinks, Cola and Cola light showed the least erosivity (p<0.001, ANOVA with Bonferroni post hoc test) whereas lemon juice showed statistically significant higher erosivity than all other drinks except Sprite and apple juice (p<0.01, ANOVA with Bonferroni post hoc test).

CONCLUSIONS

In conclusion, erosivity of common non-alcoholic drinks varies widely. For example, Sprite, apple juice, and orange juice are about five times more erosive than Coca-Cola light. The findings from the present study should be taken into account in choosing a diet that provides satisfactory nutrition while minimizing tooth erosion.

Laser speckle imaging: a novel method for detecting dental erosion

Erosion is a highly prevalent condition known as a non-carious lesion that causes progressive tooth wear due to chemical processes that do not involve the action of bacteria. Speckle images proved sensitive to even minimal mineral loss from the enamel. The aim of the present study was to investigate the use of laser speckle imaging analysis in the spatial domain to quantify shifts in the microstructure of the tooth surface in an erosion model. 32 fragments of the vestibular surface of bovine incisors were divided in for groups (10 min, 20 min. 30 min and 40 min of acid etching) immersed in a cola-based beverage (pH approximately 2.5) twice a day during 7 days to create an artificial erosion. By analyzing the laser speckle contrast map (LASCA) in the eroded region compared to the sound it was observed that the LASCA map shifts, proportionally to the acid each duration, by: 18%; 23%; 39% and 44% for the 10 min; 20 min; 30 min and 40 min groups, respectively. To the best of our knowledge, this is the first study to demonstrate the correlation between speckle patterns and erosion progression.

Erosive Effect of Different Soft Drinks on Enamel Surface in vitro: Application of Stylus Profilometry

OBJECTIVE

To assess the erosive potential of various soft drinks by measuring initial pH and titratable acidity (TA) and to evaluate enamel surface roughness using different exposure times.

MATERIALS AND METHODS

The initial pH of the soft drinks (group 1: Coca-Cola; group 2: orange juice; group 3: Cedevita; group 4: Guarana, and group 5: strawberry yoghurt) was measured using a pH meter, and TA was measured by titration with NaOH. Enamel samples (n = 96), cut from unerupted human third molars, were randomly assigned to 6 groups: experimental (groups 1-5) and control (filtered saliva). The samples were exposed to 50 ml of soft drinks for 15, 30 and 60 min, 3 times daily, during 10 days. Between immersions, the samples were kept in filtered saliva. Enamel surface roughness was measured by diamond stylus profilometer using the following roughness parameters: Ra, Rq, Rz, and Ry. Data were analyzed by one-way ANOVA, Tukey's post hoc and Student-Newman-Keuls post hoc tests.

RESULTS

The pH values of the soft drinks ranged from 2.52 (Guarana) to 4.21 (strawberry yoghurt). Orange juice had the highest TA, requiring 5.70 ml of NaOH to reach pH 7.0, whereas Coca-Cola required only 1.87 ml. Roughness parameters indicated that Coca-Cola had the strongest erosion potential during the 15 min of exposure, while Coca-Cola and orange juice were similar during 30- and 60-min exposures. There were no significant differences related to all exposure times between Guarana and Cedevita. Strawberry yoghurt did not erode the enamel surface regardless of the exposure time.

CONCLUSION

All of the tested soft drinks except yoghurt were erosive. Erosion of the enamel surfaces exposed to Coca-Cola, orange juice, Cedevita, and Guarana was directly proportional to the exposure time.

An in-vitro assessment of erosive potential of a calcium-fortified fruit juice

AIM

To evaluate and compare the in vitro pH, buffer capacity and calcium loss from tooth enamel before and after calcium fortification of a packaged fruit juice.

METHODS

An approved brand of packaged mixed fruit juice was selected as a test drink on the basis of a pilot questionnaire. The test drink was fortified with 1,000 mg/l (0.1% w/v) of calcium citrate malate to obtain two test groups: Group 1: original beverage (serving as control) and Group 2: calcium-fortified drink. The pH and buffering capacity for the test drinks were measured before and after calcium fortification; 90 prepared enamel samples were divided and immersed into three test subgroups: (1) buffer solution pH 7 (positive control), (2) original fruit juice (negative control) and (3) calcium-fortified fruit juice for 3 min. Calcium loss from the enamel of immersed teeth was measured as a quantitative estimate of tooth mineral loss.

RESULTS

After calcium fortification of the fruit juice the mean pH raised from 3.4 to 4.0 (p = 0.029), the mean buffer capacity decreased from 9.73 to 9.16 (p < 0.001) and the mean calcium loss from enamel specimens decreased from 3.5 to 0.26 mg/dl (p < 0.001).

STATISTICS

To compare the change in mean pH and buffering capacity between the subject groups, t test was used, and to compare the calcium loss from enamel specimens, among the three subgroups, ANOVA was used.

CONCLUSION

Calcium fortification of packaged fruit juice in vitro, improves its pH and buffering capacity. Consequently, the fortified juice causes significantly less mineral loss from human enamel. Fortifying juice with calcium may exert a significant protective potential against dental erosion particularly due to frequent exposure of acidic drinks.

The effect of a bioglass paste on enamel exposed to erosive challenge

OBJECTIVES

The current study is evaluating the effect of using a 45S5 bioglass paste and topical fluoride application on the cross sectional micro-hardness and the chemical surface changes of eroded enamel.

METHODS

Enamel discs were obtained from the buccal surface of one hundred extracted human non-carious third molars. The enamel surfaces were ground flat and each disc was coated with two layers of acid resistant nail varnish except for an exposed treatment window (3mm×2mm) on the buccal surface of the tooth. All specimens were challenged for 60 min by orange juice (Tropicana, Chicago, USA) pH 3.85+0.5. The specimens were divided into four groups: the 45S5 bioglass paste group, fluoride gel group (5 min application), fluoride gel group (24h application) while the rest of specimens served as control. The cross-sectional micro-hardness of 20 specimens from each group was measured. Five specimens from each group had their top eroded enamel surfaces examined by SEM-EDS. One-way ANOVA was used to compare the cross-sectional micro-hardness of the three groups p<0.05.

RESULTS

45S5 bioglass paste application significantly improved the sub-surface eroded enamel when compared to fluoride and control specimens (p<0.05).

CONCLUSION

45S5 bioglass paste can efficiently improve the micro-hardness of the sub-surface eroded enamel surface.

CLINICAL SIGNIFICANCE

The use of the 45S5 Bioglass paste can be used efficiently as a potent remineralizing agent for the sub-surface enamel lesions resulting from erosive challenges.

Relationship between daily habits, Streptococcus mutans, and caries among schoolboys

OBJECTIVES

The purpose of this study was to examine the associations between daily habits, Streptococcus mutans, and caries using International Caries Detection and Assessment System Caries Index (ICDAS CI); and compare it to the DMF index.

SUBJECTS AND METHODS

Altogether 122 children were examined and interviewed. Saliva and plaque samples were collected and analyzed by Dentocult SM(®) Strip Mutans test. ICDAS CI was calculated by counting all ICDAS caries scores of all surfaces divided by total number of carious teeth.

RESULTS

ICDAS CI was significantly (p<0.01) and strongly associated with DMFT/dmft (ρ=0.72), DMFS/dmfs (ρ=0.72), total number of carious teeth (DT/dt) (ρ=0.77), enamel caries surfaces (ρ=0.61) and dentine caries surfaces (ρ=0.75). Plaque S. mutans was significantly (p<0.05) correlated with ICDAS CI and DT/dt. Children who brushed once a day or more had significantly lower ICDAS CI (p<0.01). Children who consumed sweets or drank soft drinks more than once a day had significantly higher ICDAS CI (p<0.05). No significant association was found between ICDAS CI and frequency of flossing, use of mouthrinse, or gum chewing.

CONCLUSION

ICDAS CI seems to have similar trends as DMF indices, but includes more information about the stage, severity, and progress of the caries lesions of the patient.