International Journal of Clinical Pediatric Dentistry

Register      Login

VOLUME 15 , ISSUE 6 ( November-December, 2022 ) > List of Articles


Evaluation of Fluoride Uptake of Two Fluoride Varnishes into and onto the Enamel Surface at Different Temperatures: An In Vitro Study

Aruna P Vishwakarma, Prashant Bondarde, Prashanthkumar Vishwakarma, Arun S Dodamani, Shoeb Mujawar, Sandesh Bansal

Keywords : Enamel surface remineralization, Fluoride uptake, Fluoride varnish, Potassium hydroxide insoluble fluoride, Potassium hydroxide soluble fluoride, Temperature

Citation Information : Vishwakarma AP, Bondarde P, Vishwakarma P, Dodamani AS, Mujawar S, Bansal S. Evaluation of Fluoride Uptake of Two Fluoride Varnishes into and onto the Enamel Surface at Different Temperatures: An In Vitro Study. Int J Clin Pediatr Dent 2022; 15 (6):672-679.

DOI: 10.5005/jp-journals-10005-2449

License: CC BY-NC 4.0

Published Online: 14-02-2023

Copyright Statement:  Copyright © 2022; The Author(s).


Background: Fluoride (F) is an effective anticaries agent and can be delivered through various mediums at different concentrations. The ability to increase the enamel resistance to acid by decreasing solubility through the incorporation of F into the enamel apatite structure is the primary function of these agents. The efficacy of topical F can be determined by measuring the amount of F incorporated in and on human enamel. Aim: To compare the F uptake into and onto the enamel surface of two different F varnishes at different temperatures. Materials and methods: In this study, 96 teeth were divided equally and randomly (n = 48) into two experimental groups (group I and group II). Each group was further divided into four equal subgroups (n = 12); depending on the temperature (25°, 37°, 50°, and 60°C) they were subjected to Fluor-Protector® 0.7% and Embrace® 5% F varnishes were allocated to experimental groups I and II, respectively, and every sample was individually treated with the assigned F varnish. After the varnish application, two specimens from each subgroup, the group I and group II (n = 16), were mounted for hard tissue microtome sectioning for scanning electron microscope (SEM) analysis. The remaining 80 teeth underwent potassium hydroxide (KOH) soluble and KOH-insoluble F estimation. Results: Group I and group II, both, showed maximum F uptake of 2817.07 ppm and 1626.8 ppm at 37°C temperature and the lowest of 1168.9 ppm and 1068.93 ppm at 50°C, respectively. The intergroup comparison was carried out using an unpaired t-test and the intragroup comparison was done using one-way analysis of variance (ANOVA) univariate analysis. Post hoc Tukey test was performed for pairwise comparison between different temperature groups. In group I (Fluor-Protector®), the difference in F uptake was statistically significant when the temperature was increased from 25° to 37° C (mean difference = −9.90, p = 0.016). In group II (Embrace®), a statistically significant difference in F uptake was observed when the temperature was increased from 25° to 50°C (mean difference = 10.00, p = 0.003) and 25° to 60°C (mean difference = 13.38, p = 0.001), respectively. Conclusion: Fluor-Protector® varnish proved to have better F uptake in comparison to Embrace® varnish on human enamel. Topical F varnishes were most effective at 37°C, which is close to the standard human body temperature. Thus, the application of warm F varnish ensures more uptake of F in and onto the enamel surface for greater protection against dental caries.

PDF Share
  1. Al-Darwish M, EL Ansari W, Bener A. Prevalence of dental caries among 12-14 year old children in Qatar. Saudi Dent J 2014;26(3):115–125. DOI: 10.1016/j.sdentj.2014.03.006
  2. Zero DT, Marinho VC, Phantumvanit P. Effective use of self-care fluoride administration in Asia. Adv Dent Res 2012;24(1):16–21. DOI: 10.1177/0022034511431262
  3. American Dental Association Council on Scientific Affairs. Professionally applied topical fluoride: evidence-based clinical recommendations. J Am Dent Assoc 2006;137(8):1151–1159. DOI: 10.14219/jada.archive.2006.0356
  4. Okuno A, Nezu T, Tanaka M. A warmed topical fluoride solution enhances KOH-soluble and -insoluble fluoride formation on tooth surfaces in vitro. Pediatr Dent J 2014;24(1):22–26. DOI: 10.1016/j.pdj.2013.12.003
  5. VanRijkom HM, Truin GJ, van't Hof MA. A meta-analysis of clinical studies on the caries-inhibiting effect of fluoride gel treatment. Caries Res 1998;32(2):83–92. DOI: 10.1159/000016436
  6. Petersson LG, Twetman S, Pakhomov GN. Fluoride varnish for community-based caries prevention in children. WHO 1997;1:1–15.
  7. Mellberg JR, Loertscher KL. Fluoride acquisition in vitro by sound human tooth enamel from sodium fluoride-and ammonium silicofluoride-phosphate solutions. Arch Oral Biol 1972;17(7):1107–1116. DOI: 10.1016/0003-9969(72)90185-9
  8. Scheinin A. Studies on the acid solubility and fluorine content of sodium-fluoride-treated powdered dental enamel; effects of concentration, temperature, time and ultrasound. Suom Hammaslaak Toim 1954;50(Suppl. 2):53–64.
  9. Putt MS, Beltz JF, Muhler JC. Effect of temperature of SnF2 solution on tin and fluoride uptake by bovine enamel. J Dent Res 1978; 57(7–8):772–776. DOI: 10.1177/00220345780570070301
  10. Caslavaska V, Moreno EC, Brudevold F. Determination of calcium fluoride formed from in vitro exposure of human enamel to fluoride solutions. Archs Oral Biol 1975;20(5–6):333–339. DOI: 10.1016/0003-9969(75)90023-0
  11. Dijkman AG, De Boer P, Arends J. In vivo investigation on the fluoride content in and on human enamel after topical applications. Caries Res 1983;17(5):392–402. DOI: 10.1159/000260693
  12. Kadoma Y, Kojima K, Masuhara E. Studies on dental fluoridereleasing polymers. IV: fluoridation of human enamel by fluoride-containing sealant. Biomaterials 1983;4(2):89–93. DOI: 10.1016/0142-9612(83)90046-7
  13. Attin T, Grieme R, Paqué F, et al. Enamel fluoride uptake of a novel water-based fluoride varnish. Arch Oral Biol 2005;50(3):317–322. DOI: 10.1016/j.archoralbio.2004.09.003
  14. Belser U, Sporri S, Muhlemann HR. Uptake and retention of fluoride by intact and etched enamel. Helv Odontol Acta 1975;19(2):69–71.
  15. Beltran Aguilar ED, Goldstein JW, Lockwood SA. Fluoride varnishes. A review of their clinical use, cariostatic mechanism efficacy and safety. J Am Dent Assoc 2000;131(5):589–596. DOI: 10.14219/jada.archive.2000.0232
  16. Dijkman AG, Tak J, Arends J. Fluoride deposited by topical applications in enamel. KOH solutions and acquired fluoride. Caries Res 1982;16(2):147–155. DOI: 10.1159/000260591
  17. Caslavaska V, Moreno EC, Brudevold F. Determination of CaF2 resulting from fluoride topical treatments on enamel. J Dent Res 1974;53:21.
  18. Retief DH, Sorvas PG, Bradley EL, et al. In vitro fluoride uptake, distribution and retention by human enamel after 1- and 24-hour application of various topical fluoride agents. J Dent Res 1980;59(3):573–582. DOI: 10.1177/00220345800590030401
  19. Barrancos RJ. Effects of temperature on the uptake of topical fluorides, Master of Sciences Thesis, The University of Michigan.1966.
  20. Stookey GK, Stahlman DB. Enhanced fluoride uptake in enamel with a fluoride-impregnated prophylactic cup. J Dent Res 1976;55(3):333–341. DOI: 10.1177/00220345760550030801
  21. Rölla G, Saxegaard E. Critical evaluation of the composition and use of topical fluorides, with emphasis on the role of calcium fluoride in caries inhibition. J Dent Res 1990;69:780–785. DOI: 10.1177/00220345900690S150
  22. Cruz RA, Rölla G. The importance of calcium fluoride as fluoride reservoir on enamel surfaces. Rev Odont USP 1991;5:134–139.
  23. Hellwig E, Klimek J, Albert G. In vivo retention of KOH soluble and firmly bound fluoride in demineralized dental enamel. Dtsch Zahnarztl Z 1989;44(3):173–176.
  24. Petersson LG. In vivo fluorine uptake in human enamel following treatment with a varnish containing sodium fluoride. Odontol Revy 1975;26(4):253–266.
  25. Mellberg JR, Laakso PV, Nicholson CR. The acquisition and loss of fluoride by topically fluoridated human tooth enamel. Archs Oral Biol 1966;11(12):1213–1220. DOI: 10.1016/0003-9969(66)90014-8
  26. Brudevold F, McCann G, Nilsson R, et al. The chemistry of caries inhibition problems and challenges in topical treatments. J Dent Res 1967;46(1):37–45. DOI: 10.1177/00220345670460013801
  27. Takagi S, Liao H, Chow LC. Effect of tooth-bound fluoride on enamel demineralization/remineralization in vitro. Caries Res 2000;34(4):281–288. DOI: 10.1159/000016603
  28. Buzalaf MA, Pessan JP, Honório HM, et al. Mechanisms of action of fluoride for caries control. Monogr Oral Sci 2011;22:97–114. DOI: 10.1159/000325151
  29. Øgaard B, Rølla G, Ruben J, et al. Microradiographic study of demineralization of shark enamel in a human caries model. Scand J Dent Res 1988;96(3):209–211. DOI: 10.1111/j.1600-0722.1988.tb01545.x
  30. Subramaniam P, Telegeti S. Effect of different concentrations of fluoride varnish on enamel surface microhardness: an in vitro randomized controlled study. J Indian Assoc Public Health Dent 2016;14(3):344–347. DOI: 10.4103/2319-5932.187172
  31. Kamarudin A, Anderson P, Hill R. The effect of different fluoride varnishes on the release of calcium ions from hydroxyapatite discs: an ion-selective electrodes study. Padjadjaran J Dent 2020;32(2):82–90. DOI: 10.24198/pjd.vol32no2.26444
  32. Cruz R, Ogaard B, Rölla G. Uptake of KOH-soluble and KOH-insoluble fluoride in sound human enamel after topical application of a fluoride varnish (Duraphat) or a neutral 2% naf solution in vitro. Scand J Dent Res 1992;100(3):154–158. DOI: 10.1111/j.1600-0722.1992.tb01732.x
  33. Jeng YR, Lin TT, Wong TY, et al. Nano-mechanical properties of fluoride-treated enamel surfaces. J Dent Res 2008;87(4):381–385. DOI: 10.1177/154405910808700414
  34. Holmen L, Ogaard B, Rölla G, et al. A polarized light and scanning electron microscope study of the effect of Duraphat treatment on in vivo caries. Scand J Dent Res 1986;94(6):521–529. DOI: 10.1111/j.1600-0722.1986.tb01795.x
  35. Arends J, Christoffersen J. Nature and role of loosely bound fluoride in dental caries. J Dent Res 1990;69(2 Suppl):634–636. DOI: 10.1177/00220345900690S118
PDF Share
PDF Share

© Jaypee Brothers Medical Publishers (P) LTD.