Suppressive effects of saliva against enamel demineralization caused by acid beverages

Shoji Takahashi, Shigeru Watanabe, Takashi Ogihara, Koji Watanabe, Kun Xuan, Xiaojing Wang

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DOI: 10.4236/health.2011.312123                

Abstract

This study aimed to clarify the ability of the buffer systems of saliva to inhibit enamel demineralization after intake of an acid beverage. In the first experiment, titrable acidity tests were carried out. Ten milliliters of saliva stimulated by chewing gum base was obtained from 10 healthy adult subjects and the pH of each saliva sample was measured. The beverages used for the experiment were a carbonated soft drink (pH 2.2), a sports drink (pH 3.5), and 100% orange juice (pH 3.8). Distilled water adjusted to the pH of each saliva sample was used as a control. In the second experiment, the suppressive ability of saliva against enamel demineralization was quantitatively analyzed using quantitative light- induced fluorescence (QLF). Aliquots of stimulated saliva obtained from a subject were mixed with 15 ml of 100% orange juice in saliva:orange juice ratios of 1/30, 1/15, 1/10 and 1/5, and bovine teeth were soaked for 24 hours in the solutions. The △Q of the QLF analyses of the enamel was then measured. The lowest titrant volume which reduced the pH of the initial saliva (7.7 on average) to pH 5.4 was that of the orange juice. No relationship was found between the buffer capacity and the pH of the acid beverages. From the QLF measurement, the saliva-orange juice group showed a significantly decreased amount of enamel demineralization (p < 0.01 at 20% level) compared with the distilled water-orange juice group. In conclusion, saliva acts as a buffer to suppress enamel demineralization caused by low-pH beverages.

Keywords

Erosion; Acid Beverage; Saliva; Buffering Capacity; QLF

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	ten Cate, J.M. and Imfeld, T. (1996) Dental erosion, summary. European Journal of Oral Sciences, 104, 241-244. doi:10.1111/j.1600-0722.1996.tb00073.x
[2]	Vissink, A., Burlage, F.R., Spijkervet, F.K., Jansma, J. and Coppes, R.P. (2003) Prevention and treatment of the consequences of head and neck radiotherapy. Critical Reviews in Oral Biology & Medicine, 14, 213-225. doi:10.1177/154411130301400306
[3]	Watanabe, S. and Dawes, C. (1988) The effects of different foods and concentrations of citric acid on the flow rate of whole saliva in man. Archives of Oral Biology, 33, 1-5. doi:10.1016/0003-9969(88)90089-1
[4]	Watanabe, S. and Dawes, C. (1988) A comparison of the effects of tasting and chewing foods on the flow rate of whole saliva in man. Archives of Oral Biology, 33, 761-764. doi:10.1016/0003-9969(88)90010-6
[5]	Dawes, C. (1983) A mathematical model of salivary clearance of sugar from the oral cavity. Caries Research, 17, 321-334. doi:10.1159/000260684
[6]	Dawes, C., Watanabe, S., Biglow-Lecomte, P. and Dibdin, G.H. (1989) Estimation of the velocity of the salivary film at some different locations in the mouth. Journal of Dental Research, 68, 1479-1482. doi:10.1177/00220345890680110201
[7]	Lilienthal, B. (1955) An analysis of the buffer systems in saliva. Journal of Dental Research, 34, 516-530. doi:10.1177/00220345550340040701
[8]	Larsen, M.J., Jensen, A.F., Madsen, D.M. and Pearce, E.I.F. (1999) Individual variations of pH, buffer capacity, and concentrations of calcium and phosphate in un-stimulated whole saliva. Archives of Oral Biology, 44, 111-117. doi:10.1016/S0003-9969(98)00108-3
[9]	Bardow, A., Moe, D., Nyvad, B. and Nauntofte, B. (2000) The buffer capacity and buffer systems of human whole saliva measured without loss of CO2. Archives of Oral Biology, 45, 1-12. doi:10.1016/S0003-9969(99)00119-3
[10]	Moritsuka, M., Kitasako, Y., Burrow, M.F., Ikeda, M. and Tagami, J. (2006) The pH change after HCl titration into resting and stimulated saliva for a buffering capacity test. Australian Dental Journal, 51, 170-174. doi:10.1111/j.1834-7819.2006.tb00422.x
[11]	Ando, M., Hall, A.F., Eckert, G.J., Schemehorn, B.R., Analoui, M. and Stookey, G.K. (1997) Relative ability of laser fluorescence techniques to quantitate early mineral loss in vitro. Caries Research, 31, 125-131. doi:10.1159/000262387
[12]	de Josselin de Jong, E., Sundstrom, F., Westerling, H., Tranaeus, S., ten Bosch, J.J. and Angmar-Mansson, B. (1995) A new method for in vivo quantification of changes in initial enamel caries with laser fluorescence. Caries Research, 29, 2-7. doi:10.1159/000262032
[13]	Edgar, W.M. (1992) Saliva: Its secretion, composition and functions. Brazilian Dental Journal, 172, 305-312. doi:10.1038/sj.bdj.4807861
[14]	Owens, B.M. (2007) The potential effects of pH and buffering capacity on dental erosion. General Dentistry, 55, 527-531.
[15]	Edwards, M., Creanor, S.L., Foye, R.H. and Gilmour, W.H. (1999) Buffering capacities of soft drinks: the potential influence on dental erosion. Journal of Oral Rehabilitation, 26, 923-927. doi:10.1046/j.1365-2842.1999.00494.x
[16]	Larsen, M.J. and Nyvad, B. (1999) Enamel erosion by some soft drinks and orange juice relative to their pH, buffering effect and contents of calcium phosphate. Caries Research, 33, 81-87. doi:10.1159/000016499
[17]	Zero, D.T. and Lussi, A. (2005) Erosion-chemical and biological factors of importance to the dental practitioner. International Dental Journal, 55, 285-290.
[18]	Jensdottir, T., Holbrook, P., Nauntofte, B., Buchwald, C. and Bardow, A. (2006) Immediate erosive potential of cola drinks and orange juice. Journal of Dental Research, 85, 226-230. doi:10.1177/154405910608500304
[19]	Pretty, I.A., Edgar, W.M. and Higham, S.M. (2002) Detection of in vitro demineralization of primary teeth using quantitative light-induced fluorescence(QLF). International Journal of Paediatric Dentistry, 12, 158-167. doi:10.1046/j.1365-263X.2002.00357.x
[20]	Larsen, M.J., Pearce, E.I.F. and Jensen, S.J. (1993) Notes on the dissolution of human dental enamel in dilute acid solutions at high solid/solution ratio. Caries Research, 27, 87-95. doi:10.1159/000261523
[21]	Meurman, J.H. and Frank, R.M. (1991) Scanning electron microscopic study of the effect of salivary pellicle on enamel erosion. Caries Research, 25, 1-6. doi:10.1159/000261335
[22]	Hannig, M., Fiebiger, M., Guntzer, M., Dobert, A., Zimehl, R. and Nekrashevych, Y. (2004) Protective effect of the in situ formed short-term salivary pellicle. Archives of Oral Biology, 49, 903-910. doi:10.1016/j.archoralbio.2004.05.008