|Year : 2012 | Volume
| Issue : 1 | Page : 7-12
Impact of a modified carbonated beverage on human dental plaque and salivary pH: An in vivo study
V Sardana1, AY Balappanavar2, GB Patil3, N Kulkarni4, SG Sagari3, KD Gupta1
1 Department of Pedodontics and Preventive Dentistry, Teerthanker Mahaveer Dental College and Research Center, Moradabad, Uttar Pradesh, India
2 Public Health Dentistry, Teerthanker Mahaveer Dental College and Research Center, Moradabad, Uttar Pradesh, India
3 Department of Oral Pathology, Jodhpur National University, Jodhpur Dental College General Hospital, Jodhpur, Rajasthan, India
4 Department of Orthodontics, KM Shah Dental College, Sumandeep Vidyapeeth University, Vadodara, Gujarat, India
|Date of Web Publication||3-May-2012|
A Y Balappanavar
C/o Dr. V. N. Sardana, R 5/94, New Raj Nagar, Ghaziabad - 201 002, Uttar Pradesh
| Abstract|| |
Background: To assess the plaque and salivary pH changes at different time intervals in vivo after consumption of a carbonated beverage modified with sodium fluoride and calcium phosphate. Materials and Methods: Twenty-four subjects aged 18-25 years were recruited and randomly assigned to three groups (group A, original drink sprite; group B, sprite with sodium fluoride; group C, sprite with calcium phosphate). Collection of pooled plaque and unstimulated saliva was done before and after the drinks were consumed by the subjects at 5-, 10-, 20- and 30-minute intervals. Results: The pH rise was higher with group C for plaque and group B for saliva. Conclusions: Modification of the test carbonated beverage with calcium phosphate and fluoride may exert some protective potential, especially in high caries risk candidates.
Keywords: Calcium phosphate, carbonated beverage, dental caries, erosion, fluoride, plaque pH
|How to cite this article:|
Sardana V, Balappanavar A Y, Patil G B, Kulkarni N, Sagari S G, Gupta K D. Impact of a modified carbonated beverage on human dental plaque and salivary pH: An in vivo study. J Indian Soc Pedod Prev Dent 2012;30:7-12
|How to cite this URL:|
Sardana V, Balappanavar A Y, Patil G B, Kulkarni N, Sagari S G, Gupta K D. Impact of a modified carbonated beverage on human dental plaque and salivary pH: An in vivo study. J Indian Soc Pedod Prev Dent [serial online] 2012 [cited 2013 Jun 19];30:7-12. Available from: http://www.jisppd.com/text.asp?2012/30/1/7/95563
| Introduction|| |
The consumption of soft drinks, particularly by the young, has increased dramatically over recent decades. , Surveys have indicated that dental caries and dental erosion are becoming highly prevalent and severe in both dentitions. ,, Additional factor of significance in dental caries is the concentration of calcium, phosphate, and fluoride. Fluoride has been used successfully in the prevention of dental caries. , It is, however, an open question whether fluoride can prevent, at least to some extent, erosion of enamel caused by acidic soft drinks and fruit juices.
The pH value, the calcium, and phosphate content of a drink or foodstuff are also important factors responsible for the erosive attack and formation of dental caries. , They determine the degree of saturation with respect to the tooth mineral, which is the driving force for dissolution.  A low degree of undersaturation with respect to enamel or dentine will lead to an initial surface demineralization, which is followed by a local pH rise and increased content of mineral in the fluid layer adjacent to the surface. These fluid layers will then become saturated with respect to enamel (or dentine) and not lead to further demineralization. The deposition of salivary calcium and phosphate may lead to remineralization of the initially acid softened enamel. , The remineralization process has been shown to be greatly enhanced by fluoride treatment followed by 4 hours of intraoral exposure. 
Accepting these data, very few studies in vitro and in vivo were conducted to develop soft drinks with extremely low potential to cause dental caries and enamel erosion by modifying them by adding hydrocolloids, magnesium, calcium citrate malate, fluoride, and calcium phosphate. , Hence, this study was conducted with an aim to know the effects of drinking a carbonated beverage modified with sodium fluoride and calcium phosphate on the pH of human dental plaque and saliva. The objectives were to record the baseline pH of plaque and saliva, to record the changes in pH and compare plaque and salivary pH after consumption of a carbonated beverage modified with sodium fluoride and calcium phosphate, as well as to check for the acceptance of these drinks.
| Materials and Methods|| |
The study was carried out at the Department of Preventive and Community Dentistry, VK`s KLE`s Institute of Dental Sciences, Belgaum, India. Informed consent was obtained from the subjects and approval for the study was obtained from the KLE'S Research and Ethical Committee. All the experiments were carried out in the morning (8 a.m.-10 a.m.) to minimize variations in salivary flow and composition. A table of subject characteristics including age, sex, DMFS scores, periodontal status, and sites used for pH determination was documented.
Test drink and modification compounds
Sprite (Coca-Cola Co.), a carbonated beverage, at room temperature, with a pH of 2.98, was used as the test drink. The composition of the beverage according to manufacturers is water, sugar, carbonic acid, citric acid, and sodium citrate. The constitution of calcium, fluoride, and phosphate, when analyzed, were 0.03, 0.001, and 0.81 mmol/l, respectively.
Commercially available 250 mg sodium fluoride was added to 300 ml of drink. Calcium phosphate was prepared by adding 40 mmol/l of calcium to 28 mmol/l of phosphate, and this was added to 300 ml of beverage. The pH values of the drink after modification were 3.98 and 3.76, respectively.
Initially, 30 subjects were selected from KLE'S College of Physiotherapy, Belgaum, based on the criteria of the San Antonio Conference on Methods for Assessing Cariogenic Potential of Foods and Beverages. , Subjects with at least 20 teeth present, a minimum DMFS of 12, a salivary buffering capacity of less than or equal to 5.5, and not under any medication were included in the study. However, only 24 subjects (10 female and 14 male subjects with a mean age of 20.10 and 23.7 years, respectively) who consented to refrain from oral hygiene practice procedures for 24 hours before the test and to abstain from any food or drink (except water) for 8 hours prior to the study were finally recruited. This was a double-blind study in which the subjects, the operator recording pH, and the statistician were blinded.
The subjects were randomly divided by lottery method into three groups (eight in each group). Group A subjects consumed the plain beverage without modification from a plastic glass with straw. Group B subjects were requested to consume the beverage modified by adding sodium fluoride, whereas group C subjects consumed the drink modified by adding calcium phosphate. Each subject was given 300 ml of sprite to be consumed in 5 minutes.
Saliva and plaque sampling as well as measurement
Fosdick et al.'s , method of plaque sampling and plaque measurement was followed; sample of plaque was collected each time from buccal, lingual, and approximal surfaces of selected teeth, i.e. 16, 22, 36, and 42, with a blunt probe for 3 seconds per collection. Five samples of approximately 1 mg each, representing all the quadrants, were obtained before the subjects consumed the drink. This served as baseline data. Plaque was then immediately suspended in 10 ml of distilled water in a test tube and pH was measured using a glass combination electrode. This was again carried out at 5-, 10-, 20-, and 30-minute intervals at the same designated sites. The measurement of plaque pH was performed using Autotitrator, AT-91 (Mayura analytical pvt ltd, bangalore), which was calibrated with buffers of pH 4, 5, and 7. Calibration was performed after each 60-minute run.
The patient was instructed to expectorate any pooled saliva into the collection cup. A pH test strip (Saliva-Check Buffer kit, GC corporation, belgium) was taken and placed into the sample of resting saliva for 10 seconds and then the color of the strip was compared with the standard testing chart for pH provided by the manufacturer. The color on the chart that most closely matched the color of the pH paper was found. Any color changes that continued after 30 seconds were disregarded. This was carried out before as well as after consuming the drink at 5-, 10-, 20- and 30-minute intervals.
After 1 week of the study, four subjects were selected randomly from each group. All the subjects were blinded to the type of modified drink they consumed. They were instructed to consume the plain sprite, calcium-modified sprite, and fluoride-modified sprite one after another with a gap of 2 hours and were asked to fill the questionnaire given to them. A scale was prepared ranging from 0 (not acceptable) to 10 (completely acceptable) and an open-ended question was prepared for the reason for the number marked on the taste scale.
The data were entered and analyzed using SPSS software (version 11) with a significance level set at 0.05 and confidence interval at 95%. One-way analysis of variance (ANOVA) and the post-hoc Tukey's test were used to statistically analyze the data for intergroup comparison. Paired t-test was used for intragroup comparison. Chi-square test was used for acceptability of taste perception.
| Results|| |
The mean DMFS, salivary and plaque pH levels were 12.88 ± 0.37, 4.8 ± 0.30, and 5.86 ± 0.11, respectively. [Table 1] shows the intergroup comparison of plaque pH levels in all the groups at various time intervals. At baseline, no significant difference was observed between groups (F= 0.08, P= 0.92, NS). The drop in plaque pH from the resting value at 5 minutes was lowest when calcium phosphate modified sprite (group C) was consumed, with a mean value of 5.82 ± 0.04, followed by group B (5.50 ± 0.13) (F 34.4, P<0.01, S), with the largest drop found when the original sprite was consumed (5.30 ± 0.13), and the difference was statistically significant. Also, the plaque pH values showed statistically significant differences at 10 minutes (F 13.2, P<0.01, S) and 20 minutes (F 13.3, P<0.01, S). The post-hoc test confirmed the significance at all time intervals between group A and group B, between group A and group C, as well as between group B and group C at 5- and 10-minute intervals. The Stephan's curve was plotted for all the three groups [Graph 1]. On intragroup comparison, there was significant difference (P<0.001) in all the groups and at all time intervals except in group C at 30 minutes (t=2.49, P=0.06) which was not significant.
|Table 1: The intergroup comparison of plaque pH levels at different time intervals in all the three groups|
Click here to view
The salivary pH was nonsignificant (0.33 , NS) among the three groups and decreased after 5 minutes in all the three groups, which was found to be significant (0.01, S), with the highest fall being in group A (4.22). After 10 minutes, the salivary pH increased in all the three groups, but was more in group B (4.9) followed by group C (4.8) which was found to be statistically nonsignificant (0.10, NS). The post-hoc test confirmed the significance between groups A and B (0.56, S) as well as between groups A and C (0.48) at 5 minutes [Graph 2], [Table 2].
|Table 2: The intergroup comparison of salivary pH levels at different time intervals in all the three groups|
Click here to view
Among the 12 subjects who underwent the acceptability test, 10 had replied as acceptable and no change in taste (P=0.98).
| Discussion|| |
The present study demonstrated the reduction of the acidogenic potential of carbonated beverage by calcium phosphate and sodium fluoride. The effect may be related to the ability of the drink to maintain high levels of calcium and fluoride in the plaque during the period of active acidogenesis. However, it is generally accepted that a reduction in the acidogenic response of plaque to a challenge from fermentable is beneficial. Therefore, the post-challenge plaque pH can, to some extent, be used as a measure to indicate the relative cariogenic potential of the drinks. ,,, In our study, we used glass combination electrode to measure plaque pH, as it is an established, sensitive, and accurate methodology.  Method of drinking carbonated beverage also has an impact on the pH,  and as proved by previous studies, the straw was used to consume the drink, which shows minimal drop in pH.
Some modifications to acidic beverages have been suggested to reduce the potential of carbonated drinks to demineralize and dissolve the mineral compounds of teeth. ,,,,,,,, Addition of hydrocolloids, magnesium, calcium citrate malate, fluoride, calcium/phosphate to soft drinks has been tested. Studies have shown that high amounts of calcium, phosphate, or fluoride are able to reduce the formation of erosive lesions in enamel distinctly. ,, However, a comparison between different beverages demonstrated that even low differences in phosphate, fluoride, or calcium content of beverages are responsible for distinct differences in erosive and cariogenic potentials of the beverages.  In a recent study, 1% citric acid was supplemented with different concentrations of calcium, phosphate, and/or fluoride to reduce the erosive potential of the solution and the results were positive, though with the added concentrations, enamel dissolution could not be completely prevented.  Besides the concentration of calcium, phosphate, and fluoride, the potential of soft drinks depends on various other factors such as acid type, pH, amount of titrable acid, or buffer capacity. ,
In order to prevent dental hard tissue damage because of acidic drinks completely, it would be optimal to supplement acidic beverages with high amounts of calcium phosphate and fluoride, so that the drink is saturated with respect to apatite. Lussi et al. , had also proved that minimal differences in mineral contents (calcium, phosphate, fluoride) of beverages might have an impact on the erosive potential of soft drinks. With respect to the amount of fluoride added to the drinks, it has to be noted that fluoride is able to reduce enamel dissolution when added to a demineralizing solution of pH 4.3.  Moreover, it may be speculated that by rinsing enamel with fluoridated acidic solutions, a CaF 2 like layer is formed on the enamel surface, which on exposure to artificial saliva may lead to further remineralization and protection against further erosion.
It is important to note that the levels of calcium phosphate or sodium fluoride used in this experiment did not alter the taste. Up to 83.3% of the volunteers perceived no differences in taste between the blinded original solution and modified solution, though 16.7% reported difference in taste of modified solutions, especially in the calcium phosphate group. Therefore, it can be concluded that the modification exerts minimal effect on the taste of the beverages.
All the groups tested in our study had a fall in the plaque pH, with a gradual recovery in the pH over 30 minutes. However, the drop in pH was significantly greater when subjects used the original unmodified drink, in spite of it having the same concentration of sugar. We can only speculate on this observed beneficial effect of adding a small amount of fluoride that once the acid starts to form from the plaque by the bacterial fermentation of carbohydrate present in the drinks, fluoride, if present, through enzyme inhibition could influence the amount of acid formed and thus reduce the pH drop in the plaque, as seen in our study. Fluoride is supposed to act in concert with the other ions of the apatite lattice (calcium phosphate) and in concentrations that saturate the solution with respect to fluorapatite. ,
While modifications of acidic solutions might lead to reduction of the erosive potential and anticariogenic capacity of the solutions, it is not known whether it will hold true for the commercial beverages with more complex compositions. Therefore, optimal adjustment of an acidic beverage with respect to reducing its potential for dental erosion should be individually checked for the respective beverage. , When fluoride is present, a reduction in mineral loss and fluoride uptake by the enamel happens simultaneously during the development of decalcification. The concentrations of fluoride needed may be more to nullify the acidogenic response of these drinks, which may be toxic upon continuous exposure of these drinks. Further studies with larger sample size are required taking into consideration the buffering capacity of SALIVA, the high concentration of fluoride with safety as well as toxicity and the knowledge, attitude and practices of beverage consumption study.
In conclusion, it is difficult to imagine and would be naïve to believe that the use of these drinks can ever be stopped. Hence, it is concluded that modification of the test beverage with low concentrations of fluoride and phosphate is able to reduce the cariogenic potential of the drinks. Although the addition of low levels of calcium phosphate and fluoride to beverages does not completely eliminate their cariogenicity, it does appear to reduce the acidogenic and hence possibly the cariogenic potential of these drinks, especially with respect to high caries risk individuals.
| Acknowledgments|| |
The authors would like to thank the participants without whom the study would have not been completed. Our heartfelt thanks to Dr. Bhat, Prof. and HOD, KLE's Pharmacy College, Belgaum, for technical support.
| References|| |
|1.||Lussi A. Dental erosion: Clinical diagnosis and case history taking. Eur J Oral Sci 1996;104:191-8. |
|2.||Sucrose soft drink report: UK market reading, Tale and Lyte Industries, Limca, 1998. |
|3.||Eccles JD. Jennkins WG. Dental erosion and diet. J Dent 1974;2:153-9. |
|4.||Nunn JH. Prevalence of dental erosion and the implications for oral health. Eur J Oral Sci 1996;104:156-61. |
|5.||Zero DT. Etiology of dental erosion; extrinsic factors. Eur J Oral Sci 1996;104:162-71. |
|6.||O'Brien M. children`s dental health in the United Kingdom 1993. Office of population census and surveys. London: HMSO; 1994. |
|7.||West NX, Hughes JA, Parker DM, Newcombe RG, Addy M. Development and evaluation of erosive black current juice drink. Comparison with a conventional blackcurrant drink and orange juice. J Dent 1999;27:341-344. |
|8.||Larsen MJ. Chemically induced in vitro lesions in dental enamel. Scand J Dent Res 1974;82:496-509, 10. |
|9.||Pearce EI. A microradiogrphic and chemical comparison of in vitro systems for the simulation of incipient caries in abraded bovine enamel. J Dent Res 1983;62:969-74. |
|10.||Lussi A, Jaeggi T, Schrer S. The influence of different factors on in vitro enamel erosion. Caries Res 1993;27:387-93. |
|11.||Lussi A, Jaeggi T, Jaeggi-Schrer S. Prediction of the erosive potential of some beverages. Caries Res 1995;29:349-54. |
|12.||Larsen MJ. Dissolution of enamel. Scand J Dent Res 1973;81:518-22. |
|13.||Gedalia I, Dakuar A, Shapira L, Lewinstein I, Goultschin J, Rahamim E. Enamel softening with Coca-Cola and rehardening with milk or saliva. Am J Dent 1991;4:120-2. |
|14.||Amaechi BT, Higham SM. Eroded lesion remineralization by saliva as a possible factor in the site-specificity of human dental erosion. Arch Oral Biol 2001;46:697-703. |
|15.||DT Zero, G Cavaretta Siegel, J Fu, H Li. Effect of pyrophosphate on fluoride enhanced remineralization after an erosive challenge. Caries Res 2000;34:344. |
|16.||Hughes JA, West NX, Parker DM, Newcombe RG, Addy M. Development and evaluation of a low erosive black current juice drink in vitro and in situ 1: Comparison with orange juice. J Dent 1999a;27:255-89. |
|17.||Depaola DP. Executive summary. J Dent Res 1986;65:1540-5. |
|18.||Curzon ME. Integration of methods for determining the cariogenic potential of foods. J Dent Res 1986;65:1520-4. |
|19.||Pollard MA, Duggal MS, Curzon ME. The effect of different concentrations of citrate in drinks on plaque pH. Caries Res 1993;27:191-4. |
|20.||Duggal MS, Tahmassebi F, Pollard MA. Effect of addition of 0.103% citrate to a blackcurrant drink on plaque pH in vivo. Caries Res 1995;29:75-9. |
|21.||ADA health foundation proceedings, 1986. |
|22.||Aswini YB, Tangade PS, Ankola AV, Nagesh L, Pradnya H. The effect of different methods of drinking a carbonated beverage on the pH of dental plaque: An in vivo study. Oral Health Prev Dent 2005;3:237-41. |
|23.||Sorvari R, Kiviranta I, Luoma H. Erosive effect of a sport drink mixture with and without addition of fluoride and magnesium on the molar teeth. Scand J Dent Res 1988;96:226-31. |
|24.||Sorvari R. effects of various sports drink modifications on dental caries and erosion in rats with controlled eating and drinking pattern. Proc Finn Dent Soc 1989;85:13-20. |
|25.||Rugg-Gunn AJ, Maguire A, Gordon PH, McCabe JF, Stephenson G. Comparison of erosion of dental enamel by four drinks using an intra oral appliance. Caries Res 1998;32:337-43. |
|26.||Hughes JA, Jandt KD, Baker N, Parker D, Newcombe RG, Eisenburger M, et al. Further modification to soft drinks to minimize erosion. A study in situ. Caries Res 2002;36:70-4. |
|27.||Larsen MJ, Nyvad B. Enamel erosion by some soft drinks and orange juices relative to their pH, buffering effect and contents of calcium phosphate. Caries Res 1999;33:81-7. |
|28.||West NX, Hughes JA, Parker DM. Development and evaluation of low erosive black currant juice drink. 2. Comparison with a conventional blackcurrant juice drink compared to a conventional carbonated drink. J Dent 1999; 27:341-4. |
|29.||West NX, Hughes JA, Parker DM. Development of low erosive carbonated fruit drinks. 2. Evaluation of an experimental carbonated blackcurrant drink compared to a conventional carbonated drink. J Dent 2003;31:361-5. |
|30.||Barlett DW, Bureaug P, Anggiansah A. Evaluation of the pH of a new carbonated soft drink beverage: An in vivo investigation. J Prosthodont 2003;12:21-5. |
|31.||Beiraghi S, Atkins S, Rosen S. Effect of calcium lactate in erosion and s mutans in rats when added to coca cola. Pediatr Dent 1989;11:312-5. |
|32.||Larsen MJ, Nyvad B. Enamel erosion by some soft drinks and orange juices relative to their pH, buffering effect and contents of calcium phosphate. Caries Res 1999;33:81-7. |
|33.||Lussi A, Jaeggi T, Zero D. The role of diet in the etiology of dental erosion. Caries Res 2004;38:34-44. |
|34.||Attin T, Meyer K, Hellwig E. effect of mineral supplements to citric acid on enamel erosion. Arch Oral Biol 2003;48:753-9. |
|35.||Margolis HC, Moreno EC, Murphy BJ. Effect of low levels of fluoride in solution on demineralization in vitro. J Dent Res 1986;65:23-9. |
[Table 1], [Table 2]