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Biomedical subjects

N X West

Publications and source records attributed to N X West.

At least 19 recordsLinked to original sources

Dentine hypersensitivity.

Dentine hypersensitivity is a common oral complaint, affecting the teeth of many individuals. The aetiology is multifactorial; however, over recent years the role of erosion has become more and more important. For dentine hypersensitivity to occur, the lesion must first be localised on the tooth surface and then initiated to exposed dentine tubules which are patent to the pulp. The short, sharp pain symptoms are thought to be derived from the hydrodynamic theory of pain. This episodic pain condition is likely to become a more frequent dental complaint in the future due to the increase in longevity of the dentition and the rise in tooth wear. However, conclusive evidence of successful treatment regimens still eludes us despite a multitude of products available for treatment. In explanation, pain studies are notoriously difficult to conduct due to the subjective nature of pain and the complexity of pain assessment. The basic principles of treatment are altering fluid flow in the dentinal tubules with tubule occlusion or modifying or blocking pulpal nerve response, chemically with agents like potassium or physically.

Dental Materials↗

A methodology for testing the erosive potential of sports drinks.

OBJECTIVES: The aim of the study was to develop and test a methodology in situ, which simulated the consumption of sports drinks. A secondary aim was to assess the acceptability of the method to sedentary participants. METHODS: To select the sports drink for the study in situ, five commercially available sports drinks were examined for erosive potential in vitro. The study in situ was a single centre, 2-period, 2-treatment crossover study to compare the erosive effect of a commercially available sports drink (Test), with that of mineral water (Control), over 10 day periods on 10 healthy volunteers. Subjects wore upper removable appliances containing two human enamel specimens from 9 a.m. to 5 p.m. The regimen of intake of the drinks was 350 ml in 10, 5-min rest, 650 ml in 25, 5-min rest, 500 ml in 10 and 5-min rest. Measurements of enamel loss were made on samples after 5 and 10 days by profilometry. RESULTS: The in situ study showed a statistically significant difference in erosive potential between the test and control beverages. No specimen exposed to the control beverage displayed appreciable erosion. Erosion occurred with the test drink, but to a variable degree between subjects. The subjects unanimously found the drinking regimen unpleasant. CONCLUSIONS: The sports drink caused significantly more erosion in situ than water and as seen in other studies, there was marked variation in susceptibility to erosion between subjects. The new drinking regimen was designed to simulate pre, during and post-exercise intake. Although all the sedentary subjects participating in this study reported that they found the volume of fluids consumed over a short period of time excessive it is unlikely that this would prove problematic in the exercise environment.

Adult↗

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

OBJECTIVE: To compare the erosive effect of a new blackcurrant/calcium drink with xanthan gum, on enamel in situ, with a low erosive product, a conventional fruit beverage and water. DESIGN: The study was single centre, randomised, single blind, 4 treatment crossover design. SETTING: This study, conducted in 2000, employed volunteers working at the Bristol Dental Hospital, UK. SUBJECTS, MATERIALS AND METHODS: 16 subjects (>or=18 years) wore two enamel samples in a removable acrylic appliance. The drinks tested were (A) New blackcurrant/calcium/gum drink (test product), (B) Original blackcurrant/calcium drink, (C) Conventional blackcurrant drink (positive control) and (D) Water (negative control), for 15 day study periods. Drinking was supervised, with 250 ml imbibed four times/day between 9.00am-5.00pm. Profile measurements of specimens were made at baseline, 5, 10 and 15 days. MAIN OUTCOME MEASURES: Paired t-tests compared erosion by surfometry with selected pairs of formulations. RESULTS: Of 16 screened subjects (3 male, 13 female), mean age 34.2 years, 1 subject failed to complete the study. A caused significantly less enamel loss than C, with no statistically significant differences from B at any time points measured. Of 43 treatment emergent adverse events, none were considered related to the study formulations. CONCLUSIONS: A retained low erosive properties similar to B, with additional benefits of taste flexibility and beverage stability.

Adolescent↗

A comparison of enamel erosion by a new sports drink compared to two proprietary products: a controlled, crossover study in situ.

OBJECTIVE: The aim of the study was to measure the erosive potential of a prototype sports drink on enamel in a model in situ. METHODS: The study was a single centre, single blind, randomised crossover design balanced for residual effects involving 18 subjects. The drinks were the prototype formulation containing calcium and maltodextrin (test), two sports drink products containing sugars (drink with calcium and positive control) and water (negative control). During each 15-day study period, subjects wore a palatal removable appliance carrying two flat human enamel specimens. Drinks were imbibed as 250 ml volumes over 10 min 4 times per day. Loss of enamel was measured on days 5, 10 and 15 using a contacting profilometer. RESULTS: Very little erosion occurred with the test, drink with calcium and negative control drinks and differences between the test and negative control only reached significance at day 15. The positive control produced progressive erosion over time and significantly more than the test or negative control at all time points. CONCLUSION: The technology of adding calcium with appropriate pH adjustment, which has been applied previously to soft and carbonated drinks to markedly reduce erosive potential, can be applied to sports drinks to the same end. Significant variation in the carbohydrate composition does not influence this outcome.

Adult↗

The protective effect of fluoride treatments against enamel erosion in vitro.

Fluoride is known to reduce enamel solubility during the caries process. The aim of this investigation was to determine whether fluoride preparations affect erosion attributed to citric acid and citric acid-based soft drinks. Flat enamel specimens embedded in epoxy resin were prepared from caries free, human third molar teeth extracted from patients aged 18-35 years. Specimens were polished to have a profile within a tolerance of +/-0.3 microm measured on a profilometer. Specimens were taped to leave a 2 mm window of exposed enamel. Groups of specimens were exposed to citric acid and soft drinks with and without the addition of sodium fluoride or exposed to the same solutions after pre-treatment with fluoride products. Enamel loss was measured by profilometer after 10, 20 and 30 min of acid exposure. The different acidic solutions varied significantly in the amount of erosion produced both with and without the addition of fluoride. In addition, the different fluoride products differed significantly in the protective effect afforded. Both fluoride application methods reduced in mean terms, enamel erosion at all time points and by all acidic solutions. The majority of differences were <25% and as the study was powered to show differences as significant at or above this level few reached statistical significance. Fluoride applied to enamel either in acidic solutions or as a pre-treatment, reduces enamel erosion; however, the actual clinical benefit appears low. More studies are required, including investigations in situ.

Adolescent↗

Development of low erosive carbonated fruit drinks. 1. Evaluation of two experimental orange drinks in vitro and in situ.

OBJECTIVES: To determine the in vitro erosive potential and in situ erosive effect of two new formulation low calorie carbonated orange drinks with that of two conventional diet products and water. METHODS: In the in vitro study, six specimens of deciduous and permanent enamel were randomly allocated to each of the five products and a '4h' protocol employed. In the in situ study, 15 healthy volunteers participated in a single centre, single blind, 5-phase crossover study, conducted according to Good Clinical Practice, and employing a validated model. RESULTS: The in vitro erosive potential of the experimental formulations was less than that of the comparators at all time points. Conversely, the observed erosive potential of both experimental formulations was greater than that of the control. Consistent statistically significant differences were found in relation to permanent enamel only. Unfortunately, the in situ study did not produce results entirely consistent with those of the in vitro study. Notably, a generally progressive loss of enamel was observed in specimens exposed to the control. CONCLUSIONS: The data from the in vitro study show the experimental formulations to have low comparative erosivity. However, the methodologies in vitro and in situ somewhat unusually do not correlate in ranking the erosivity of drinks. The results of this study should therefore be viewed with caution, further research being clearly warranted.

Adolescent↗

Development of low erosive carbonated fruit drinks 2. Evaluation of an experimental carbonated blackcurrant drink compared to a conventional carbonated drink.

OBJECTIVE: Previous studies demonstrated that a non-carbonated blackcurrant juice drink with added calcium produced little erosion of enamel in vitro and in situ by comparison with other low pH fruit drinks. The aim of this study is to evaluate the erosive effects in situ of an experimental formulation carbonated drink with added calcium, compared to a conventional carbonated drink over a 20 day period using a similar design as in previous studies. METHOD: The study was a single centre, single blind, randomised placebo controlled three cell crossover design involving 15 volunteers. The test drinks were an experimental carbonated ready-to-drink (RTD) blackcurrant drink, a conventional carbonated RTD orange drink and water. Two enamel samples were retained in situ, in the midline of the hard palate on an upper removable acrylic appliance. Drinks were 250 ml volumes consumed four times per day during 20 working days. Measurements of enamel loss were made on enamel samples after days 2, 5, 10, 15 and 20 by profilometry. RESULTS: The experimental carbonated blackcurrant drink caused significantly less enamel loss than the conventional carbonated orange drink at all time points measured, but was not significantly different from water at days 2, 5 and 20. CONCLUSIONS: This study has shown that it is possible to modify carbonated soft drinks in a manner similarly shown with non-carbonated soft drinks, to minimise dental erosion.

Adult↗

Investigation of erosion and abrasion on enamel and dentine: a model in situ using toothpastes of different abrasivity.

BACKGROUND: Studies in vitro suggest that abrasion and erosion may act synergistically to produce wear of enamel and dentine. Methods in situ are recently available to study separately erosion and abrasion of dental tissues. The aim of this study was to combine two in situ protocols to study the interplay between erosion and abrasion of enamel and dentine. METHOD: The study was a single-blind, randomised, five-treatment cross-over design involving 15 healthy volunteers. During each 10-day study period, subjects wore from 0900 to 1700 h an upper removable acrylic appliance holding one polished enamel and one polished dentine specimen. The specimen treatment regimens were: 1. Drinking water and brushing with toothpaste A. 2. Drinking water and brushing with toothpaste B. 3. Drinking orange juice. 4. Drinking orange juice and brushing with toothpaste A. 5. Drinking orange juice and brushing with toothpaste B. Drinking and brushing times were around 0900, 1100, 1300 and 1500 h. Drinks were consumed as 250 ml over 10 min and brushing ex vivo for 1 min to each specimen. Measurement of tissue loss was made on days 5 and 10 of each period using a profilometer. RESULTS: All treatments produced increasing tissue loss over time, which was considerably greater for dentine than enamel. For enamel, the data at days 5 and 10 showed a significant effect for erosion (i.e. orange juice was significantly more erosive than water), but no significant effect for abrasion (i.e. no significant difference between the two toothpaste treatments). The combined orange juice and toothpaste effects were directional for synergy but did not reach significance. For dentine at day 10, many specimens exceeded the 50 microm set limit of the profilometer and only day 5 data were considered. There were significant effects for erosion (orange juice produced significantly more erosion than water) and for abrasion (paste A was significantly more abrasive to dentine than paste B). The synergy effect could not be examined for dentine due to the truncation effect as the set limit of the profilometer was exceeded. CONCLUSIONS: Erosion increases the susceptibility of enamel to toothpaste abrasion. Dentine is considerably more susceptible than enamel to erosion and abrasion alone or combined. Dentine loss appears to correlate with toothpaste abrasivity (RDA value).

Adolescent↗

Dentine hypersensitivity: the effects of brushing toothpaste on etched and unetched dentine in vitro.

Although many people have exposed dentine, only a percentage exhibit symptoms of dentine hypersensitivity. This has been ascribed to opening and closing of the dentinal tubules by for example, smear layer changes or tubular occlusion. The aims of this study were to examine the surface morphological changes of etched and unetched dentine in vitro, attributed to the effects of toothbrushing with and without toothpastes designed for the alleviation of dentine hypersensitivity. A total of 96 etched and 96 unetched human dentine specimens were brushed with various toothpastes and water for 1, 2, 5 or 10-min periods in a toothbrushing machine and subsequently examined under scanning electron microscopy for surface changes. Analyses of brushed etched specimens demonstrated that time and treatment were significant variables (P < 0.05) for tubule occlusion. Further, the interaction between time and treatment was significant (P < 0.05). The artificial silica based paste was significantly better for all time intervals at occluding the dentine tubules. All toothpastes investigated caused dynamic changes to the smear layer of the unetched dentine, opening tubules. However, the artificial silica based paste resulted in occluded rather than patent tubules. All of the pastes evaluated had the capacity to remove the smear layer but some could then occlude tubules through the contained abrasives.

Acid Etching, Dental↗

The effect of pH on the erosion of dentine and enamel by dietary acids in vitro.

The reported incidence of tooth erosion caused by acidic soft drinks has been increasingly documented. Citric and phosphoric acids are the two main dietary acids present in these soft drinks. Many variables need to be determined in order to assess risk factors for dental erosion caused by beverage consumption including pH, titratable acidity, pKa, buffering capacity, hence the aim of these in vitro investigations. Methodologies included profiling flat enamel and dentine samples (< +/- 0.3 microm profile) from unerupted human third molars. Groups of five specimens were placed in acidic solutions adjusted with alkali over the available pH range; citric, phosphoric and hydrochloric acid were adjusted with sodium hydroxide and citric acid with trisodium citrate. Tissue loss was calculated by profilometry. Results showed that under these conditions citric acid caused far more erosion over the pH range employed than phosphoric acid for both tissue types. Citric acid compared with hydrochloric acid highlighted dissolution and chelation effects. Phosphoric acid caused minimal erosion over pH 3 for enamel and pH 4 for dentine. These factors could be considered in order to reduce the erosivity of acidic soft drinks.

Adult↗

Effects of pH and concentration of citric, malic and lactic acids on enamel, in vitro.

OBJECTIVE: Dental erosion associated with soft drink consumption probably results from the contained dietary acids in the formulations. The pH value of any formulation is an important variable in acid erosion but not necessarily the only important factor. The aim of this study was to measure enamel erosion by citric, malic and lactic acids at pH values and acid concentrations representative of a range found in soft drink formulations and to determine the effect of adding calcium to citric acid. METHODS: Flat ground enamel samples were prepared from unerupted human third molar teeth. Groups of five specimens were placed in citric, malic and lactic acid solutions of different pH and acid concentration for three by 10 min exposures at 35 degrees C. Enamel loss was measured by profilometry. Enamel specimens were also exposed to citric acid solutions containing calcium at different pH values and at the same pH with different concentrations of calcium. RESULTS: Numerical data and contour plots for each acid showed a similar pattern for increasing erosion with decreasing pH and increasing acid concentration and vice versa for decreasing erosion. Increasing the concentration of calcium in a fixed pH citric acid solution resulted in decreased erosion. This effect was most marked at higher pH. CONCLUSIONS: This study has shown that under highly controlled conditions the erosion of enamel by solutions of dietary acids is influenced by the interplay of pH, acid concentration and presence of calcium. These variables and in particular the concentration of calcium could be manipulated to produce soft drinks with reduced erosivity to enamel.

Beverages↗

Relative susceptibility of deciduous and permanent dental hard tissues to erosion by a low pH fruit drink in vitro.

OBJECTIVES: The objectives of this study were two-fold: (1) to determine (by surfometry) loss of deciduous and permanent enamel and dentine following 15days' exposure to a single low pH orange drink; and (2) to determine (by surfometry) loss of deciduous and permanent enamel and dentine following exposure to the product 2 versus 4 times per day for 15days. METHODS: This in vitro study employed the validated methodology described by West and co-workers [Journal of Dentistry, 1998;26:329-335.] RESULTS: In all four tissues, erosion was progressive over time, though this pattern was more linear in enamel than in dentine. In general, erosion of enamel was greater in the deciduous tissue, while erosion of dentine was greater in the permanent tissue. However, these differences were rarely of statistical significance. Increasing frequency of exposure resulted in a non-proportional increase in tissue loss. CONCLUSIONS: Differences in susceptibility of deciduous and permanent tissues to erosion by a low pH drink in vitro appear to exist, though these may not be of statistical significance. Care may be indicated in the delivery of dietary advice, since reduced frequency of exposure to a low pH drink does not appear to result in a proportional reduction in tissue loss.

Adolescent↗

Erosion of deciduous and permanent dental hard tissue in the oral environment.

OBJECTIVES: The objectives of this study were two-fold: (1) to determine (by surfometry) loss of deciduous and permanent enamel and dentine following consumption of a single low pH orange drink for 15days; and (2) to determine (by surfometry) loss of deciduous and permanent enamel and dentine following consumption of the product 2 versus 4 times per day for 15days. METHODS: Sixteen healthy volunteers participated in a single centre, single blind, 2-phase crossover study, conducted according to Good Clinical Practice, and employing the validated model described by West and co-workers (Journal of Dentistry 1998; 26:329-335). RESULTS: In all tissues, erosion was progressive over time, the pattern being more linear in enamel than in dentine. In general, erosion of deciduous enamel was greater than that of permanent enamel, though this difference was significant only for those specimens exposed to 4 drinks per day. Conversely, erosion of dentine was generally greater in the permanent tissue, though differences rarely reached conventional levels of statistical significance. Increasing frequency of consumption resulted in increased loss of tissue, but this difference was neither proportional nor consistently statistically significant. CONCLUSIONS: It is concluded that statistically significant differences in susceptibility of deciduous and permanent enamel to erosion appear to emerge over time and with increasing frequency of consumption. This is of importance clinically given the reduced dimensions of the deciduous dentition and the element of 'abuse' of soft drinks by the child population. Further development of soft drinks with low erosive potential is recommended.

Adult↗

Erosion of dentine and enamel in vitro by dietary acids: the effect of temperature, acid character, concentration and exposure time.

Sales of soft drinks has been increasing by 56% over the last 10 years and are estimated to keep rising at about 2-3% a year. Further, the reported incidence of tooth erosion has been increasingly documented. Whilst these factors could well be linked, many individuals with erosive diets are not presenting with erosion. This would suggest the effects of many variables, hence the aim of these investigations. Methodologies included preparing enamel and dentine samples from unerupted human third molars. Groups of five specimens were placed in citric acid over a temperature range of 5-60 degrees C for 10-min exposures; placed in citric, lactic, malic or phosphoric acid (0.05, 0.1, 0.5, and 1% (w/v)) for 10-min exposures; and placed in the same three organic hydroxy acids at 0.3% (w/v) or phosphoric acid at 0.1% (w/v) for 3 x 10-min exposures. Tissue loss was determined by profilometry. Results showed that increasing temperature, concentration and exposure time increased the erosion of dentine and enamel. This study has shown that under highly controlled conditions, erosion of dentine and enamel by dietary acids can be greatly influenced in vitro by temperature, concentration, type of acid and exposure time. These factors could be employed in order to reduce the erosivity of soft acidic drinks.

Adolescent↗

Development and evaluation of a low erosive blackcurrant juice drink. 3. Final drink and concentrate, formulae comparisons in situ and overview of the concept.

OBJECTIVE: Two previous studies demonstrated that a blackcurrant juice drink with added calcium produced little erosion of enamel in vitro and in situ by comparison with other low pH fruit drinks. The primary aim of this study was to demonstrate that the final formulation drink and concentrate were of similar low erosivity. Secondary aims were to provide more data on the erosivity of other fruit drink concentrates and whether erosion was influenced by anterior and posterior palate siting of enamel specimens. METHOD: The study was a single centre, single blind, randomised placebo controlled 5 cell crossover design involving 15 volunteers. The test drinks were blackcurrant juice/calcium concentrate, blackcurrant juice/calcium drink, proprietary apple & blackcurrant juice concentrate, proprietary orange drink concentrate and water. Four enamel samples were retained in situ, 2 anterior palate and 2 mid/posterior palate, on upper removable acrylic appliances. Drinks were 250 ml volumes consumed 4 times per day during 15 working days. Concentrates were diluted 50 ml in 200 ml water. Measurements of enamel loss were made on one anterior and one posterior sample on days 2, 5, 10 and 15 by profilometry. RESULTS: One subject approached the 20 microns erosion limit by day 10 on the orange drink and was withdrawn from that cell. Differences in mean erosion between anterior and posterior sites were variable and small. By day 15 the mean losses of enamel averaged over anterior and posterior were blackcurrant/calcium concentrate 0.28 micron, blackcurrant/calcium drink 0.35 micron, apple & blackcurrant concentrate 2.04 microns. orange concentrate 8.29 microns and water 0.08 micron. Except at day 15 for the blackcurrant/calcium drink the erosion by the blackcurrant/calcium formulations was not significantly different from water at any time point. Erosion by the apple & blackcurrant and orange concentrate drinks was highly significantly greater than the blackcurrant/calcium drinks at all but the 2 day time point for the apple & blackcurrant concentrate drink compared to the blackcurrant/calcium drink. CONCLUSIONS: All data thus far indicate that dependant on tooth site susceptibility and the specific drink, the consumption of standard low pH fruit drinks could result in 1 mm loss of enamel in periods ranging from as little as 2 years to 20 years. Similar erosion by the low pH blackcurrant drinks with added calcium would take in excess of 100 years.

Adult↗

Development and evaluation of a low erosive blackcurrant juice drink in vitro and in situ. 1. Comparison with orange juice.

OBJECTIVE: The aim of this study was to determine whether an experimental blackcurrant juice drink with added calcium was less erosive to enamel both in vitro and in situ compared with a proprietary orange juice product. METHODS: The study was a single centre, blind, randomised, placebo controlled three cell crossover design. An intra oral appliance capable of retaining one enamel sample in situ was constructed and worn by 12 volunteers. The drinks under test were orange juice, the experimental blackcurrant juice drink with calcium and water. Drinks were consumed as 250 ml volumes four times during the working day under supervision for 15 days. The same methodology was modelled in vitro. Measurements of enamel loss were made by profilometry. RESULTS: Water, the experimental blackcurrant juice drink and orange juice produced 0.19, 0.41 and 2.54 microns loss of enamel respectively in situ and 0.0, 5.2 and 22.18 microns loss of enamel respectively in vitro. All differences between pairs of drinks in situ and in vitro were statistically significant. CONCLUSIONS: Data using this model in situ were only available for orange juice and this was therefore considered as a positive control with water a placebo control. The results have demonstrated that the experimental blackcurrant juice drink with calcium is markedly less erosive than orange juice, particularly and importantly in situ. The experimental blackcurrant juice drink has limited erosive potential to teeth and deserves further comparative investigation and development as a low pH fruit drink for public consumption.

Adult↗

Development and evaluation of a low erosive blackcurrant juice drink. 2. Comparison with a conventional blackcurrant juice drink and orange juice.

OBJECTIVE: A previous study demonstrated that an experimental low pH blackcurrant juice drink with calcium was markedly less erosive to enamel both in situ and in vitro than orange juice. Further development of the experimental blackcurrant juice drink formula has occurred and the aims of the present studies were two fold. Firstly, to confirm the low erosivity of the modified formulation and secondly, to provide more comparative data with other acidic fruit drink products. METHOD: The study was a single centre, single blind, randomised placebo controlled 4 cell crossover design involving 12 healthy volunteers. The test drinks were orange juice, water, experimental blackcurrant juice drink with calcium and a proprietary blackcurrant juice drink. Enamel samples were retained in situ at the mid palatal regions using intraoral appliances and exposed to 250 ml volumes of the drinks 4 times per day during 15 working days. Measurements of enamel loss were made by profilometry. The same method was modelled in vitro. RESULTS: By day 15 the mean losses of enamel in situ for orange juice, water, experimental blackcurrant juice drink with calcium and blackcurrant juice drink were 1.70, 0.05, 0.44 and 2.75 microns respectively. At all bar one measurement, the loss of enamel was significantly greater for all fruit drinks compared to water. Losses caused by the blackcurrant juice drink with calcium were significantly less than the other two fruit drinks at all time points. Losses of enamel by day 15 in the study in vitro were 13.02, 0.00, 1.78 and 39.02 microns respectively. The blackcurrant juice drink with calcium was not significantly different from water at days 3 and 6, otherwise all pairwise comparisons for differences between the 4 drinks at each time period were significant. CONCLUSIONS: The methodologies in situ and in vitro again appear to correlate in ranking the order of erosivity of drinks. The data particularly from the study in situ allude to the very low comparative erosivity of the further modified experimental blackcurrant juice drink with calcium and support the further development of such drinks for public consumption.

Adult↗

A method to measure clinical erosion: the effect of orange juice consumption on erosion of enamel.

OBJECTIVE: Acidic soft drinks are frequently implicated in dental erosion, but there are limited supporting data. Research is problematic due to the insidious nature of erosion and accuracy in assessing tissue loss. The aim of this study was to develop and validate, using a negative control, a model to accurately measure erosion in situ due to a single aetiological agent over a relatively short time period. METHODS: An intra-oral appliance capable of retaining an enamel sample was designed in order to assess the effect of orange juice consumption on enamel. The study was a single centre, randomized, placebo controlled, blind, crossover design. RESULTS: Ten subjects, each consuming 11 of orange juice per day for 15 days, showed significantly more erosion on the enamel specimens than the same subjects consuming 11 of water per day over the same time period, measurements undertaken with surfometry. The same investigation was performed in vitro. Again, orange juice was significantly more erosive; indeed, it was in the order of 10 times that produced in situ. Surface microhardness testing in situ and in vitro demonstrated statistically significant differences between exposed and unexposed areas after orange juice treatment. CONCLUSIONS: Changes produced by water either in situ or in vitro were always well within the baseline measurement parameters (+/- 0.3 micron) set down for the method and hence validated the clinical model in terms of reproducibility and accuracy in measurement. It is concluded that this method has confirmed the erosive potential of orange juice in situ. The method could have many applications to study dental erosion under highly controlled conditions and over realistic time periods.

Adult↗