The erosive potential of commercially available mouthrinses on enamel as measured by Quantitative Light-induced Fluorescence (QLF)

Fluoride, pH Value, and Titratable Acidity of Commercially Available Mouthwashes

AIM

The primary objective of this work was to assess total soluble fluoride (TSF), pH values, and titratable acidity (TA) of various mouthwashes "in vitro," and the second was to compare fluoride content on labels with measured TSF.

METHODS

Commercial mouthwashes were collected and analysed. Company, type, manufacturer data, and active ingredients (essential oils [EO], cetylpyridinium chloride [CPC], chlorhexidine [CHX], and fluoride) were described. TSF, pH, and TA capacity were measured. Descriptive quantitative analysis were performed per mouthwash.

RESULTS

In total, 54 mouthwashes from 20 brands were included. These included mouthwashes with the active ingredients EO (n = 11), CPC (n = 17), CHX (n = 18), and fluoride (n = 32); 27 mouthwashes with more than 1 of these active ingredients; and 4 with none of the above-mentioned ingredients. Fluoride was present in different formulations; most contained sodium fluoride (NaF), and a few had sodium monofluorophosphate and amine fluoride + NaF. The pH values of all evaluated mouthwashes ranged from 4.1 to 7.9. Twenty mouthwashes presented pHs below 5.5, of which 10 contained fluoride. TA ranged from 0 to 48. According to the manufacturer data, mouthwashes with fluoride had concentrations from 217 to 450 ppm, with 90% in the range from 217 to 254 ppm. Laboratory data revealed that TSF ranged from 229 to 500 ppm, with 90% in the range from 229 to 337 ppm. A statistically significant difference was observed between measured TSF and the labelled fluoride content on the packaging of the fluoride mouthwashes (mean difference, 43.92 ± 34.34; P < .001). Most of these mouthwashes contained at least the amount of fluoride as mentioned on the packaging (93%).

CONCLUSION

The pH values and TA of commercially available mouthwashes showed a large variation. TSF levels of the fluoride mouthwashes were found to be at least the amount of fluoride as labelled. Dental care professionals should be aware of the pH, TA, fluoride content, and other active ingredients of different mouthwashes to better understand their potential impact on oral health.

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.

Effect of mouthwashes on the discoloration of bracket-bonded tooth surfaces: an in vitro study

OBJECTIVES

This in vitro study aimed to investigate the color changes of the bracket-bonded tooth surfaces after the use of 4 different mouthwashes.

MATERIALS AND METHODS

A total of 100 human premolar teeth were randomly divided into 10 equal groups. Color values (L*a*b*) of the buccal surfaces of each tooth were assessed using a digital spectrophotometer. Then the brackets were bonded. The groups were put either in sterile saline (4 test+1 control) or artificial saliva (4 test+1 control) solutions, and test groups were immersed in their mouthwashes (Colgate Plax, Listerine Cool Mint, Klorhex, and Tantum Verde) for 1 min each in the morning/evening to simulate the mouth washing for 21 days after the bonding. After the debonding and finishing procedures, final color measurements were performed. Color changes (∆E) were calculated.

RESULTS

All of the parameters showed statistically significant differences among the groups. The least noticeable color changes were detected in the control groups. The most noticeable color change (ΔE) was observed in the Tantum Verde + artificial saliva group, followed by Tantum Verde + sterile saline and Klorhex + artificial saliva groups, all of which were significantly higher than the control groups.

CONCLUSION

The use of mouthwashes during orthodontic treatment may cause noticeable changes in tooth color. Listerine Cool Mint may be the choice of mouthwash with its less discoloring effects. Artificial saliva should be preferred in similar in vitro studies to reflect the oral environment better.

CLINICAL RELEVANCE

Mouthwash use during orthodontic treatment may result in different levels of enamel discoloration.

Effect of Mouth Rinse Treatments on Bleached Enamel Properties, Surface Morphology, and Tooth Color

OBJECTIVE:

To evaluate, in vitro, the effect of mouth rinse exposure on bleached enamel.

METHODS:

Enamel/dentin bovine blocks (4×4×2 mm) were bleached with 35% hydrogen peroxide (HP) and were submitted to immersion twice daily for 14 days with different rinses (n=10), including those involving: distilled water (C [control]), 225-ppm NaF (FM, Colgate Plax Classic), essential oil (EM, Listerine Tartar Control), 1.5% hydrogen peroxide (HPM, Colgate Plax Whitening), and 2% hydrogen peroxide, pyrophosphates, and 225-ppm NaF (HPM+P, Colgate® Luminous White). The specimens were stored in a remineralizing solution during all experiments. Analyses of color (ΔE, L*, a*, b*) and roughness (Ra) were performed at the baseline, after HP, and after exposure to the rinse. The cross-sectional microhardness (CSMH) and images by scanning electron microscopy (SEM) were assessed at the end. The data were subjected to analysis of variance (ANOVA) (ΔE), repeated measures ANOVA (Ra), and split-plot ANOVA (CSMH), followed by the Tukey test. The L*, a*, and b* values were analyzed by generalized linear models (α=0.05).

RESULTS:

Color changes were not statistically different in the groups. Ra increased in all groups after bleaching; however, it was reestablished in C, FM, and HPM+F and increased in EM after 14 days of the rinse. EM and HPM reduced the CSMH values differing from C and promoted alterations on the enamel surface visualized by SEM.

CONCLUSION:

The mouth rinses did not affect the whitening efficacy or promote benefits on bleached enamel properties. Moreover, the 1.5% hydrogen peroxide- or essential oil-based mouth rinses affected the bleached enamel properties, promoting an alteration in morphologic surface and mineral loss in depth.

In vitro quantitative comparison of erosive potential of infant mouthwashes on glass ionomer cement

Background

The widespread use of mouthwashes, specially in children, is a concern, since the long-term use may modify the topography of dental materials. However, this process still unclear regarding the wear related to infant mouthwashes on glass ionomer cement. Thus, the purpose of this investigation was evaluate the erosive potential of infant mouthwashes on glass ionomer cement specimens.

Material and Methods

Forty round-shaped specimens were divided into 4 groups (N=10) and submitted to erosive cycling for 15 days, being exposed 2X/day in the following children’s active agents mouthwash solutions: G1- cetylpyridinium chloride, G2- xylitol and triclosan and G3 - Malva sylvestris and xylitol. Prior to cycling, the specimens were submitted to the surface roughness measurement. After erosive cycling, the specimens were reanalyzed, and calculated the increase of roughness (∆Ra). Additionally, it was adopted distilled water as a negative control (G4). As an extra analysis, the mouthwashes had their pH values measured. The results were submitted to T-test and ANOVA followed by Tukey test at 5%.

Results

In relation to pH values, G2 presented the most acidic pH value (pH = 6.83) in comparison to other substances. Regarding the comparison of the final roughness values (R) among the groups, it was verified that the mouthwashes showed significant roughness increase in comparison to control group, especially to G3 group (Rf = 1.67 ± 0.14) as well the ΔRa values with statistical difference in comparison to distilled water. Still, with exception of control group outcome, an increase of roughness of each mouthwash was verified after the studied period.

Conclusions

Active agents present in infant mouthwashes were capable of roughness increased of glass ionomer cement surface, demonstrating an erosive potential of this material largely used in pediatric dentistry.

Key words:Dental erosion, dental cements, mouthwash.

In vitro effects of alcohol-containing mouthwashes on human enamel and restorative materials

The objective of this study was to evaluate the in vitro effects, including surface morphological characteristics and chemical elemental properties, of different mouthwash formulations on enamel and dental restorative materials, simulating up to 6 months of daily use. Human enamel samples, hydroxyapatite, composite resin, and ceramic surfaces were exposed to 3 different mouthwashes according to label directions - Listerine® Cool Mint®, Listerine® Total Care, and Listerine® Whitening - versus control (hydroalcohol solution) to simulate daily use for up to 6 months. The samples were analyzed using scanning electron microscopy (SEM), infrared spectrophotometry (µ-Fourier transform infrared microscopy), energy-dispersive X-ray (EDX) spectroscopy, and color analysis before and after exposure. No relevant changes were observed in the morphological characteristics of the surfaces using SEM techniques. The physical and chemical aspects of the enamel surfaces were evaluated using mid-infrared spectroscopy, and EDX fluorescence was used to evaluate the elemental aspects of each surface. There was no variation in the relative concentrations of calcium and phosphorus in enamel, silicon and barium in composite resin, and silicon and aluminum in the ceramic material before and after treatment. No relevant changes were detected in the biochemical and color properties of any specimen, except with Listerine® Whitening mouthwash, which demonstrated a whitening effect on enamel surfaces. Long-term exposure to low pH, alcohol-containing, and peroxide-containing mouthwash formulations caused no ultra-structural or chemical elemental changes in human enamel or dental restorative materials in vitro.

Efficacy of different strategies in protecting enamel against demineralization during fixed orthodontic treatment

BACKGROUND AND OBJECTIVE

Sealant application is a common strategy for preventing enamel demineralization during multibracket treatment. The aim of this study was to assess the efficacy in enamel demineralization prevention of two fluoride-containing enamel varnishes compared to a non-fluoride varnish, weekly fluoride gel application, and a non-treated control group.

MATERIALS AND METHODS

Enamel specimens obtained from 75 human upper permanent incisors were randomly allocated to five trial groups (each n = 15): A), ProSeal (Reliance), B), Maximum Cure® (Reliance), C), CervitecPlus (Ivoclar Vivadent, Schaan, Liechtenstein), D) elmex® gelée (GABA, Lörrach, Germany), and E), a non-treated control group. Groups A-C received a baseline varnish application, whereas group D specimens received a once weekly gel application for 2 min. Six demineralization cycles per day were carried out for 5 min each using 0.05 M citric acid, with the specimens stored in remineralization solution between cycles. Lesion depth expressed in percentage fluorescence loss (Δ-F in %) compared to baseline (T0) was assessed quantitatively with light-induced fluorescence (QLF) after 3 (T1), 7 (T2), 14 (T3), and 30 (T4) days globally and for each time point, and analyzed for compounds using the Kruskal-Wallis test (α = 5%), and additional one-sample Wilcoxon tests for each time/compound combination (Bonferroni-corrected α-levels α* = 0.05/4 = 0.0125).

RESULTS

Significant fluorescence loss revealing greater lesion depth was detected in the untreated controls (E) at T3, and in groups A (ProSeal) and C (CervitecPlus) at T4. No significant Δ-F changes were seen in the specimens from groups B (Maximum Cure®) and D (elmex® gelée).

CONCLUSION

Maximum Cure® sealant seems to offer efficient protection against demineralization during fixed orthodontic treatment, as does weekly application of elmex® fluoride gel.

Fiber optic backscatter spectroscopic sensor to monitor enamel demineralization and remineralization in vitro

In this study, a Fiber Optic Backscatter Spectroscopic Sensor (FOBSS) is used to monitor demineralization and remineralization induced changes in the enamel. A bifurcated fiber optic backscatter probe connected to a visible light source and a high resolution spectrophotometer was used to acquire the backscatter light spectrum from the tooth surface. The experiments were conducted in two parts. In Part 1, experiments were carried out using fiber optic backscatter spectroscopy on (1) sound enamel and dentine sections and (2) sound tooth specimens subjected to demineralization and remineralization. In Part 2, polarization microscopy was conducted to examine the depth of demineralization in tooth specimens. The enamel and dentine specimens from the Part-1 experiments showed distinct backscatter spectra. The spectrum obtained from the enamel-dentine combination and the spectrum generated from the average of the enamel and dentine spectral values were closely similar and showed characteristics of dentine. The experiments in Part 2 showed that demineralization and remineralization processes induced a linear decrease and linear increase in the backscatter light intensity respectively. A negative correlation between the decrease in the backscatter light intensity during demineralization and the depth of demineralization determined using the polarization microscopy was calculated to be p = -0.994. This in vitro experiment highlights the potential benefit of using FOBSS to detect demineralization and remineralization of enamel.

Effect of selected mouthwashes on the surface roughness of resin modified glass-ionomer restorative materials

OBJECTIVES

It is known that the use of mouthwashes and toothbrushing can affect some restorative dental materials. The purpose of this laboratory study was to investigate the effect of four commercially available mouthwashes on the surface roughness of a number of resin modified glass-ionomer restorative materials when used with and without tooth brushing.

METHODS

Specimens of the restorative materials in the study (Vitremer, Compoglass and Dyract) were prepared. Half of the specimens were only exposed to a mouthwash (Plax, Macleans, Listerine, Corsodyl or deionised water as control). The remaining specimens were exposed to one of the mouthwashes in conjunction with tooth brushing. The initial surface roughness and the subsequent changes in surface roughness were assessed by scanning electron microscopy (SEM) and profilometry. The assessment times were: baseline, 4, 12 and 24 weeks.

RESULTS

Initial SEM observations of the surface morphology of the specimens revealed a rougher surface for Vitremer in comparison to the other two materials. Assessments at increasing time intervals showed that specimens exposed to a mouthwash only appeared to become rougher. The appearance of specimens exposed to mouthwash and brushing seemed to become even rougher with increasing time. The results of the profilometric assessment showed that at 24 weeks, specimens exposed to mouthwash only, had an overall increase in the surface roughness values for all three materials investigated. The differences between groups allocated to different mouthwashes were not however statistically significant (P>0.05). Exposure to mouthwash and toothbrushing over the same time period resulted in an increase in roughness values in all groups. The differences between mouthwash groups were not statistically significant at this stage (P>0.05).

SIGNIFICANCE

Exposure of the materials investigated to the mouthwashes included in the study had adverse effects on surface roughness. The adverse effects were more pronounced with tooth brushing.

Drug-induced disorders of teeth

It is essential that every health care professional who is involved with the prescription or recommendation of drugs be fully aware of any resultant disorders that may arise as a side-effect. A range of drugs can affect the teeth. In this review article, drugs that have the potential to induce changes in teeth have been classified as those leading to tooth discoloration (intrinsic and extrinsic), physical damage to tooth structure (enamel, dentin, and cementum), and alteration in tooth sensitivity.

Method to Detect Minimal Amounts of Calcium Dissolved in Acidic Solutions

The study describes the application of the Arsenazo III method for detection of minimal amounts of calcium 12.4-49.4 micromol/l in different acidic solutions (hydrochloric acid, oxalic acid, maleic acid, phosphoric acid, tartaric acid, citric acid, lactic acid and acetic acid) adjusted to pH 2.0, 2.3 and 3.0. A mixture of the respective calcium concentrations with distilled water served as control. The experiments were run with ten repeats in series. Assessment of intra- and interassay coefficient of variation, and lower limit of quantification revealed that depending on the acid used, the Arsenazo III method is a reliable tool to quantify minimal calcium contents in acidic solutions.

Suitability of a malachite green procedure to detect minimal amounts of phosphate dissolved in acidic solutions

The study describes the suitability of a colorimetric method (malachite green procedure) for detection of minimal amounts of phosphate (7.3-29.1 micromol/L) in different acidic solutions (hydrochloric acid, oxalic acid, maleic acid, perchloric acid, tartaric acid, citric acid, lactic acid and acetic acid) adjusted to pH 2.0. A mixture of the respective phosphate concentrations with distilled water served as control. The experiments were run with ten repeats in series. Assessment of intra- and interassay coefficient of variation and lower limit of quantification revealed that depending on the acid used, the applied method is a reliable and suitable tool to detect and quantify minimal phosphate contents in small samples of acidic solutions that have the potential to cause erosive dental lesions.

The laboratory assessment of enamel erosion: a review

OBJECTIVES

To review the various methods and techniques available to assess enamel erosion in vitro.

DATA

Peer reviewed scientific articles.

SOURCES

Medline and Web of Science searches and manual searching.

STUDY SELECTION

Laboratory based assessments only included.

CONCLUSIONS

A number of macroscopic and microscopic techniques have been used to assess enamel erosion in vitro and in situ. This review examines techniques which are either well established or comparatively novel techniques that are being explored for their potential.

The validation of Quantitative light-induced fluorescence to quantify acid erosion of human enamel

OBJECTIVE

The purpose of this study was to validate the Quantitative light-induced fluorescence (QLF) device against transverse microradiography (TMR) with regard to the quantification of enamel erosion in vitro.

DESIGN

Longitudinal in vitro.

METHODS

Thirty previously extracted, caries free, human premolars were selected and prepared by gentle pumicing and coating in an acid-resistant nail-varnish save for an exposed window on the buccal surface. QLF baseline images were taken and the teeth then exposed to an erosive solution, 0.1% citric acid (pH 2.74). Teeth were removed at 30min intervals, air-dried and QLF images taken. At this time one tooth was randomly selected, removed from solution and sectioned through the lesion at three sites. The polished sample (100microm) was subjected to TMR and analysed for erosive mineral loss using proprietary software, with the DeltaZ values noted. QLF images were analysed by a blinded examiner with DeltaF and DeltaQ values recorded. Data were entered into SPSS and the correlation between the DeltaZ and DeltaF, and DeltaZ and DeltaQ values calculated.

RESULTS

A wide range of erosive lesions was produced, with a steady increase in both DeltaZ and DeltaF over time; DeltaZ (24.0 (S.D. 1.2)-6114.3 (S.D. 1177.57)); DeltaF (1.8-11.2), DeltaQ (2.5-202.6). The results were scatter plotted and a regression line calculated. A positive correlation between DeltaZ and DeltaF of 0.91 was found, and for DeltaZ and DeltaQ; 0.87.

CONCLUSIONS

The ability for QLF to detect and longitudinally monitor in vitro erosion has been shown. The strong positive correlation of DeltaF with DeltaZ suggests that percentage fluorescence loss as measured by QLF could be of great value in the development of a non-destructive, longitudinal tool for use in vitro, in situ and possibly in vivo.