Modification of soft drinks with xanthan gum to minimise erosion: a study in situ

Addition of substances to reduce the erosive potential of acidic beverages to tooth enamel: A scoping review

OBJECTIVE

This scoping review aimed (1) to map, analyse, interpret and synthesize data from in situ studies on which substances were added to acidic beverages to reduce the erosive potential on tooth enamel and (2) to establish the level of evidence of the effectiveness of adding substances to acidic beverages to reduce the erosive potential on tooth enamel.

DESIGN

This is a scoping review, according to the methods from the Joanna Briggs Institute and PRISMA-ScR, with high-sensitivity searches in the databases PubMed (MEDLINE), Virtual Health Library, Embase (Elsevier), Scopus (Elsevier), Web of Science and ScienceDirect (Elsevier). In situ studies published in English until December 2022 were included. Studies that did not report a control group were excluded. To map and summarize the results, tables and figures were used.

RESULTS

From 895 potentially eligible articles, nine were included. Blackcurrant juices (n = 5) with the addition of calcium (n = 3) or xanthan gum (n = 2) formulations were the most tested in terms of reducing the erosive potential of the beverages on tooth enamel. The profilometer was the equipment of choice (n = 8) for evaluating the loss of enamel structure after the experimental tests.

CONCLUSIONS

Calcium and xanthan gum are among the most tested by in situ studies, offering promising results in reducing the erosive potential of fruit juices and carbonated and energy drinks.

The Effect of Food Polymers (Pectin, Alginate, and Gum Arabic) on Carbonated Drink-Induced Enamel Demineralization: An In Vitro Study

INTRODUCTION

The increased use of soft drinks leads to a high prevalence of dental erosion (DE), and the use of polymers can decrease tooth demineralization by a carbonated drink. Assessment of the effect of food-approved polymers such as highly esterified pectin (HP), propylene glycol alginate (PGA), and gum arabic (GA) on their efficiency to reduce enamel demineralization on addition with a commercially available carbonated drink was the main objective of this study.

MATERIALS AND METHODS

For this study, 300 premolar teeth were studied for enamel erosion and were divided into five groups consisting of 60 samples in each group. The teeth treated with distilled water had negative control, a commercially available carbonated drink with pH 2.7 had positive control, and food polymers were added individually to the carbonated drink in a specified quantity with minimal pH change and were taken as groups A, B, and C, respectively. The enamel erosion that occurred in study groups was measured using a laser fluorescence spectroscopic system with laser excitation at 404 nm at different treatment times (30, 60, and 120 seconds).  Results: Demineralization was less in samples treated with polymer added to carbonated drink solutions compared to samples exposed to plain carbonated drink. As the time of exposure increased up to 120 seconds, a significant decrease in demineralization occurred in polymer-treated groups of samples as against plain carbonated drink with HP showing more decreased demineralization with extended exposure periods compared to other polymers. The surface morphology of tooth samples exhibited the anti-erosive effect of polymers, and the scanning electron microscopic pictures revealed a smoother surface for the polymer-added group.

CONCLUSION

This study shows the efficacy of HP, PGA, and GA on reducing the effect of carbonated drink-induced enamel demineralization, and these polymers' addition to drinks can be an innovative way to reduce the demineralization potential of carbonated acidic drinks.

The role of calcium in the prevention of erosive tooth wear: a systematic review and meta-analysis

OBJECTIVES

The loss of hard dental tissue due to recurrent acid challenges and mechanical stresses without bacterial involvement is known as erosive tooth wear (ETW). Many studies in the literature have concentrated on variables that may affect the ETW process and prevent its occurrence or reduce its advancement. However, to date, no previous systematic review has evaluated the role of calcium in preventing ETW. Therefore, the purpose of the present systematic review was to review and critically appraise the scientific evidence regarding the role of calcium formulations in the prevention of ETW.

METHODS

The review protocol was registered in the PROSPERO international prospective register of systematic reviews (Ref: CRD42021229819). A literature search was conducted in electronic databases to identify in situ randomized controlled trials evaluating the prevention of ETW following the application of calcium formulations. The outcomes studied included mean enamel loss, surface microhardness, surface roughness, mean erosion/softening depth, mineral loss/precipitation and remineralization. Study characteristics and outcomes of included studies were summarized. Cochrane's risk-of-bias tool 2.0 was used to assess the quality of eligible studies, and meta-analysis using a random effects model was performed.

RESULTS

The search retrieved 869 studies of which 21 were considered eligible. Regarding the results of the quality assessment for potential risk of bias in all included studies, overall, 5 studies were considered as being at low risk, another 12 at unclear risk and 4 at high risk of bias. The findings of the studies showed that the addition of calcium in juice drinks led to reduced enamel loss, with blackcurrant juice presenting 2.6 times statistically significant less enamel loss compared to orange juice (p = 0.0001, I2 = 89%). No statistically significant difference in mean surface microhardness of eroded enamel was recorded between chewing gum with or without casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) (p = 0.31, I2 = 71%). Contradictory were the results regarding the effect of milk and CPP-ACP pastes on prevention of ETW.

CONCLUSIONS

Calcium formulations play an important role in ETW prevention, mainly through their addition to acidic drinks.

Film-Forming Polymers for Tooth Erosion Prevention

Different agents have been proposed to prevent the progression of acid induced dental substance losses, which are called erosive tooth wear (ETW), such as fluorides, calcium, and phosphate-based products; however, there is a need for a further increase in efficacy. Recently, the ability of polymers to interact with the tooth surface, forming acid resistant films, has come into the focus of research; nevertheless, there is still the need for a better understanding of their mode of action. Thus, this article provides an overview of the chemical structure of polymers, their mode of action, as well as the effect of their incorporation into oral care products, acid beverages, and antacid formulations, targeting the prevention of ETW. Recent evidence indicates that this may be a promising approach, however, additional studies are needed to confirm their efficacy under more relevant clinical conditions that consider salivary parameters such as flow rate, composition, and clearance. The standardization of methodological procedures such as acid challenge, treatment duration, and combination with fluorides is necessary to allow further comparisons between studies. In conclusion, film-forming polymers may be a promising cost-effective approach to prevent and control erosive demineralization of the dental hard tissue.

Impact of a simplified in situ protocol on enamel loss after erosive challenge

This study investigated the effect of the period of use and location of intraoral appliances on enamel surface loss. This randomized, single blind in situ study was conducted in 2 crossover phases based on the period of use, in which maxillary and mandibular appliances were simultaneously worn. Bovine enamel blocks (n = 120) were randomly divided among the studied groups by surface hardness. In each phase, fifteen volunteers used one maxillary appliance and two mandibular appliances for 5 days. Erosive challenge was performed 4X/day by immersion in 0.01 M HCL for 2 minutes. In the continuous phase, the intraoral appliances were worn for 20 hours. In the intermittent phase the appliances were worn for 8 hours and 30 minutes. Enamel loss was determined profilometrically. The discomfort of use of the appliances were evaluated in a questionnaire. Data were analyzed by two-way ANOVA/Tukey’s test and chi-square test (p<0.05). The maxillary appliance promoted higher enamel loss compared to the mandibular one (p<0.001). Intermittent use of appliances resulted in similar enamel loss to the continuous one (p = 0.686). All volunteers preferred to use the maxillary appliance in an intermittent regimen. The intermittent use of maxillary appliance is a simplified reliable protocol appropriated for in situ erosion studies in enamel.

Effect of different salivary exposure times on the rehardening of acid-softened enamel

This in situ study assessed the effect of different times of salivary exposure on the rehardening of acid-softened enamel. Bovine enamel blocks were subjected in vitro to a short-term acidic exposure by immersion in 0.05 M (pH 2.5) citric acid for 30 s, resulting in surface softening. Then, 40 selected eroded enamel blocks were randomly assigned to 10 volunteers. Intraoral palatal appliances containing 4 enamel blocks were constructed for each volunteer, who wore the appliance for 12 nonconsecutive hours: initial 30 min, followed by an additional 30, and then by an additional 1 hour. For the last additional 10 hours the appliances were used at night, during the volunteers' sleep. Surface hardness was analyzed in the same blocks at baseline, after erosion and after each period of salivary exposure, enabling percentage of surface hardness recovery calculation (%SHR). The data were tested using repeated measures ANOVA and Tukey's test (α = 0.05). Increasing periods of salivary action promoted a progressive increase in the surface hardness (p < 0.001). However a similar degree of enamel rehardening (p = 0.641) was observed between 2 hours (49.9%) and 12 hours (53.3%) of salivary exposure. Two hours of salivary exposure seems to be appropriate for partial rehardening of the softened enamel surface. The use of the intraoral appliance during sleep did not improve the enamel rehardening after erosion.

In vitro Efficacy of Experimental Chitosan-Containing Solutions as Anti-Erosive Agents in Enamel

The present study evaluated the effect of chitosans with different viscosities, dissolved in an AmF/SnCl2 solution, against erosion or erosion/abrasion. A total of 192 specimens were assigned to 2 × 6 groups (n = 16 specimens each): negative control, 4 chitosan solutions (groups Ch50, Ch500, Ch1000, and Ch2000, with viscosity of 50, 500, 1,000, or 2,000 mPas, respectively, 0.5% chitosan, 500 ppm F-, 800 ppm Sn2+, pH 4.4), and positive control (500 ppm F-, 800 ppm Sn2+, pH 4.3). One half of the groups was demineralized (experiment 1, E1; 10 days, 6 × 2 min/day, 0.5% citric acid, pH 2.8) and exposed to solutions (2 × 2 min/day); the other half was additionally brushed (15 s, 200 g) with non-fluoridated toothpaste before solution immersion (experiment 2, E2). Treatment effects were investigated by profilometry, energy-dispersive X-ray spectroscopy and scanning electron microscopy (SEM). In E1, all the chitosan-containing solutions reduced enamel loss by 77-80%, to the same extent as the positive control, except for Ch2000 (p ≤ 0.05), which completely inhibited tissue loss by the formation of precipitates. In E2, Ch50 and Ch500 showed best performance, with approximately 60% reduction of tissue loss compared to the negative control group (p ≤ 0.05 compared to other groups). SEM analysis showed differences between negative control and the other groups but only minor differences amongst the groups treated with active agents. In both E1 and E2, treatment with active agents resulted in surface enrichment of carbon and tin compared to negative control (p ≤ 0.001); brushing removed parts of carbon and tin (p ≤ 0.001). Chitosan shows different properties under erosive and erosive/abrasive conditions. Under erosive conditions high viscosity might be helpful, whereas lower viscosity seems to be more effective in cases of chemo-mechanical challenges.

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.

A randomised in situ trial, measuring the anti-erosive properties of a stannous-containing sodium fluoride dentifrice compared with a sodium fluoride/potassium nitrate dentifrice

OBJECTIVES

To determine if a stabilised, stannous-containing sodium fluoride dentifrice provides greater enamel protection in situ against intraoral dietary erosive challenges compared with a sodium fluoride/potassium nitrate dentifrice.

METHODS

A single-centre, investigator blind, randomised, supervised, two-treatment, non-brushing, four-period crossover in situ study was undertaken, with each test period being 15 days. Thirty-five healthy adult subjects were recruited to participate in the study, which included four erosive acid challenges per day. Subjects were randomised to product treatment, which included either: (1) a stannous-containing sodium fluoride dentifrice (Oral-B(®) Pro-Expert Sensitive) or (2) a sodium fluoride/potassium nitrate dentifrice (Sensodyne(®) Pronamel(®) ). Each study subject wore an intraoral appliance retaining two sterilised, polished human enamel samples for 6 hours/day. Subjects swished with an allocated dentifrice slurry twice a day and with 250 ml of orange juice for 10 minutes (25 ml/minute over a 10-minute period) four times per day. The primary and secondary outcomes for this study were enamel loss measured using contact profilometry at days 15 and 5, respectively, using parametric analysis methods.

RESULTS

At day 15, a 38% lower enamel loss (P < 0.0001) was observed, with estimated medians of 2.03 μm (SE 0.247) and 3.30 μm (SE 0.379), in favour of the stannous-containing dentifrice. At day 5, specimens treated with the stannous-containing sodium fluoride dentifrice demonstrated 25% less enamel loss than those treated with the sodium fluoride/potassium nitrate dentifrice. Treatment differences at day 5 were also statistically significant (P < 0.05), with estimated medians of 1.37 μm (SE 0.177) and 1.83 μm (SE 0.223), respectively.

CONCLUSIONS

Results of this in situ study suggest the stabilised, stannous-containing sodium fluoride dentifrice could be used to provide significantly greater protection to enamel from erosive acid challenge compared with that provided by conventional fluoride-containing products.

Randomised in situ study on the efficacy of a tin/chitosan toothpaste on erosive-abrasive enamel loss

Tin is a notable anti-erosive agent, and the biopolymer chitosan has also shown demineralisation-inhibiting properties. Therefore, the anti-erosive/anti-abrasive efficacy of the combination of both compounds was tested under in situ conditions. Twenty-seven volunteers were included in a randomised, double-blind, three-cell crossover in situ trial. Enamel specimens were recessed on the buccal aspects of mandibular appliances, extraorally demineralised (6 × 2 min/day) and intraorally treated with toothpaste slurries (2 × 2 min/day). Within the slurry treatment time, one-half of the specimens received additional intraoral brushing (5 s, 2.5 N). The tested toothpastes included a placebo toothpaste, an experimental NaF toothpaste (1,400 ppm F(-)) and an experimental F/Sn/chitosan toothpaste (1,400 ppm F(-), 3,500 ppm Sn(2+), 0.5% chitosan). The percentage reduction of tissue loss (slurry exposure/slurry exposure + brushing) compared to placebo was 19.0 ± 47.3/21.3 ± 22.4 after use of NaF and 52.5 ± 30.9/50.2 ± 34.3 after use of F/Sn/chitosan. F/Sn/chitosan was significantly more effective than NaF (p ≤ 0.001) and showed good efficacy against erosive and erosive-abrasive tissue loss. This study suggests that the F/Sn/chitosan toothpaste could provide good protection for patients who frequently consume acidic foodstuffs.

Primary prevention of dental erosion by calcium and fluoride: a systematic review

BACKGROUND

Overviews of the current literature only provide summaries of existing relevant preventive strategies for dental erosion.

OBJECTIVES

To perform a systematic review according to the quantitative meta-analysis method of the scientific literature on prevention of dental erosion. The focused question will address primary prevention of dental erosion by calcium and fluoride.

MATERIALS AND METHODS

Randomized clinical trials (RCTs) regarding dental erosion prevention. The search included five databases: Embase, Cochrane database of systematic reviews, PubMed (MEDLINE), FDA publication and Berman medical library of the Hebrew University. The search included data in the English language, with effect on preventing dental erosion always presented as mean enamel loss and measured by profilometer. Statistical meta-analysis was performed by StatsDirect program and PEPI statistical software. Fixed- and random-effect models were used to analyse the data. Heterogeneity tests were employed to validate the fixed-effect model assumption.

RESULTS

A total of 475 articles on dental erosion prevention were located. A four-stage selection process was employed, and 10 RCT articles were found to be suitable for meta-analysis.

CONCLUSIONS

The number of studies on prevention of dental erosion maintaining standards of evidence-based dentistry remains insufficient to reach any definite conclusions. The focused questions of this review cannot be addressed according to the existing literature.

Effect of Acidic Solution Viscosity on Enamel Erosion

The objective of this in vitro study was to investigate the effects of viscosity changes of different acidic solutions on dental erosion. Bovine enamel samples (n = 240, Ø = 3 mm) were embedded in acrylic resin and were allocated to 30 groups (n = 8). Citric acid (CA) and phosphoric acid (PA) solutions at pH 2.5, 3, and 3.5 were prepared in de-ionized water (titratable acidity to pH 5.5: 31 ± 0.6 mmol OH-/l). The kinetic viscosities of the acidic solutions were adjusted to 1.5, 3, 6, 12, and 24 mm2/sec by the addition of hydroxypropyl cellulose (HPC) at different concentrations. Solutions were pumped over the enamel surface from a reservoir with a drop rate of 1 mL/min. Each specimen was eroded for 10 min at 20°C. Erosion of enamel surfaces was measured by profilometry. Data were analyzed by analyses of variance and logarithmic regression analyses ( p < 0.05). Enamel loss was dependent on viscosity, pH, and the kind of acid. The regression analyses showed that higher viscosity caused lower enamel erosion for both acids and all pH levels. Dental erosion is dependent not only on chemical factors of the acid, like pH and acid type, but also on acid viscosity.

One-to-one dietary interventions undertaken in a dental setting to change dietary behaviour

BACKGROUND

The dental care setting is an appropriate place to deliver dietary assessment and advice as part of patient management. However, we do not know whether this is effective in changing dietary behaviour.

OBJECTIVES

To assess the effectiveness of one-to-one dietary interventions for all ages carried out in a dental care setting in changing dietary behaviour. The effectiveness of these interventions in the subsequent changing of oral and general health is also assessed.

SEARCH METHODS

The following electronic databases were searched: the Cochrane Oral Health Group Trials Register (to 24 January 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 1), MEDLINE via OVID (1950 to 24 January 2012), EMBASE via OVID (1980 to 24 January 2012), CINAHL via EBSCO (1982 to 24 January 2012), PsycINFO via OVID (1967 to 24 January 2012), and Web of Science (1945 to 12 April 2011). We also undertook an electronic search of key conference proceedings (IADR and ORCA between 2000 and 13 July 2011). Reference lists of relevant articles, thesis publications (Dissertations Abstracts Online 1861 to 2011) were searched. The authors of eligible trials were contacted to identify any unpublished work.

SELECTION CRITERIA

Randomised controlled trials assessing the effectiveness of one-to-one dietary interventions delivered in a dental care setting.

DATA COLLECTION AND ANALYSIS

Abstract screening, eligibility screening and data extraction decisions were all carried out independently and in duplicate by two review authors. Consensus between the two opinions was achieved by discussion, or involvement of a third review author.

MAIN RESULTS

Five studies met the criteria for inclusion in the review. Two of these were multi-intervention studies where the dietary intervention was one component of a wider programme of prevention, but where data on dietary behaviour change were reported. One of the single intervention studies was concerned with dental caries prevention. The other two concerned general health outcomes. There were no studies concerned with dietary change aimed at preventing tooth erosion. In four out of the five included studies a significant change in dietary behaviour was found for at least one of the primary outcome variables.

AUTHORS' CONCLUSIONS

There is some evidence that one-to-one dietary interventions in the dental setting can change behaviour, although the evidence is greater for interventions aiming to change fruit/vegetable and alcohol consumption than for those aiming to change dietary sugar consumption. There is a need for more studies, particularly in the dental practice setting, as well as greater methodological rigour in the design, statistical analysis and reporting of such studies.

Clinical in situ study investigating abrasive effects of two commercially available toothpastes

The aim of this study was to determine if the abrasive effect on dentine of two commercially available toothpastes, known to vary in their in vitro abrasive levels, can be differentiated in an in situ model after 10 days, assessed by contact profilometry. This was a single centre, single blind, randomized, split mouth, two treatment, in situ study, in 34 healthy subjects, evaluating the abrasive effects of two marketed desensitizing toothpastes, (Colgate Sensitive Multi Protection toothpaste - C; Sensodyne Total Protection - S). Subjects wore bi-lateral, lower buccal appliances, each fitted with four dentine sections which were power brushed three times a day with the treatment regimen. Each subject received two toothpaste treatments for 10 days during the treatment period. Samples were measured at baseline and day 10 by contact and non-contact profilometry and day 5 by contact profilometry. Thirty-four subjects were included in the efficacy analysis. Results from contact profilometry showed statistically significant (P < 0.0001) dentine loss compared to baseline at day 5 and 10 for both pastes. At each time point, C showed statistically significantly greater dentine loss than S, P < 0.0001. After 10 days treatment, the difference in dentine loss between the pastes was 1.4 microm. The non-contact profilometry data showed similar trends. After 10 days of treatment, C showed statistically significantly greater dentine loss than S, with treatment difference of 0.9 microm, P = 0.0057. The methodology used has successfully differentiated between the abrasivity of the two pastes in respect of dentine surface loss over time in an in situ environment.

A clinical study in situ to assess the effect of a food approved polymer on the erosion potential of drinks

OBJECTIVES

The consumption of acidic soft drinks continues to rise as do concerns regarding effects of frequent intake. The aim of the study was to determine the effect of acidic soft drinks containing food approved polymers, on dental enamel.

METHODS

The study design was a single blind, randomised, five-treatment crossover clinical trial involving 15 healthy dentate subjects. Subjects wore an upper removable acrylic appliance retaining two enamel specimens and consumed 250ml of beverage four times/day for 10 days. The following beverages were tested: (1) unmodified acidic soft drink, (2) experimental acidic soft drink with 0.02% polyphosphate, (3) experimental acidic soft drink with 0.02% polyphosphate and 0.01% calcium, (4) experimental acidic soft drink with 0.02% polyphosphate and 0.03% xanthan gum, and (5) mineral water. Tissue loss was measured at days 5 and 10 of each study leg using a profilometer.

RESULTS

The order of erosion from most to least at day 10 was unmodified acidic soft drink>experimental acidic soft drink with polyphosphate>experimental acidic soft drink with polyphosphate+gum>experimental acidic soft drink with polyphosphate+calcium>mineral water. At day 10 the unmodified acidic soft drink was significantly (p=0.001) more erosive than all other drinks.

CONCLUSIONS

Unmodified acidic soft drink with the addition of polyphosphate alone or combined with calcium or xanthan gum are all effective at reducing erosion of enamel compared with the unmodified soft acidic drink.

Soft drinks and dental health: a review of the current literature

In recent years there has been increased interest in the role of commercial soft drinks in dental diseases namely as dental caries and erosion. The objective of this paper has been to review the past and current literature to determine the present knowledge on this subject. The literature related to dental caries, erosion, drinks, soft drinks and fruit juices was reviewed. The literature shows efforts have been taken to modify soft drinks by either adding or deleting certain components so as to reduce their harmful effects on teeth. A rational protocol to encourage the sensible use of drinks and the modification of drinks to render them less harmful would be advisable.