Contemporary Clinical Dentistry
   
  Home | About us | Editorial board | Search
Ahead of print | Current Issue | Archives | Advertise
Instructions | Online submission| Contact us | Subscribe |

 

Login  | Users Online: 1647  Print this pageEmail this pageSmall font sizeDefault font sizeIncrease font size 



 
 Table of Contents  
ORIGINAL ARTICLE
Year : 2019  |  Volume : 10  |  Issue : 3  |  Page : 423-427  

Fluoride concentration in saliva following professional topical application of 2% sodium fluoride solution


1 Oral Health Centre, Governemnt Medical College and Hospital, Chandigarh, India
2 Oral Health Sciences Centre, Department of Pedodontics and Preventive Dentistry, Post Graduate Institute of Medical Education and Research, Chandigarh, India
3 Oral Health Sciences Centre, Department of Pedodontics and Preventive Dentistry, Post Graduate Institute of Medical Education and Research, Chandigarh; Department of Pedodontics and Preventive Dentistry, ITS Dental College Ghaziabad, Uttar Pradesh, India
4 Department of Staticstics, Panjab University, Chandigarh, India

Date of Web Publication11-Mar-2020

Correspondence Address:
Dr. Manjit Talwar
Oral Health Centre, Government Medical College and Hospital, Sector 32, Chandigarh - 160 030
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ccd.ccd_681_18

Rights and Permissions
   Abstract 


Background: Topical fluoride application in moderate and high-risk individuals and in those living in low-fluoride communities has been a common practice by dental professionals. Objectives: The objective of this study was to assess fluoride concentration available in saliva after a professional 2% sodium fluoride solution application (9000 ppm), and the duration of its availability to have an evidence-based practice for application. Materials and Methods: Two percent sodium fluoride application was carried out in 45 participants residing in a boarding school. The participants were non tea drinkers and nonfluoride users. Water fluoride of the area ranged from 0.34 ppm to 0.38 ppm. Whole mixed saliva samples were collected at baseline and various time intervals postapplication of 2% sodium fluoride solution. Fluoride in saliva was estimated using the fluoride combination electrode (Orion model 94–09, 96–09) coupled to an ionanalyzer. Results: IBM SPSS statistics version 23.0 was used for the analysis. Normality of the data was assessed using the Kolmogorov–Smirnov test and box plot, and it was found to be nonnormal. Wilcoxon signed-rank test was used to compare all time intervals with baseline, and statistically significant differences were observed (P = 0.0001). Salivary fluoride according to this study showed a biphasic clearance pattern with a peak at 15 min and a rapid fall in 60 min followed by a slow, consistent decline over a 20-h period. The fluoride concentration in saliva remained elevated above baseline from 0.03 ppm to 0.076 ppm even 3 months after application. Conclusion: Findings of this study show that, in this population, the frequency of application should be between 2 and 3 months (four applications per year).

Keywords: Clearance pattern, dental practice, fluoride, saliva, sodium fluoride, topical application


How to cite this article:
Talwar M, Tewari A, Chawla H S, Sachdev V, Sharma S. Fluoride concentration in saliva following professional topical application of 2% sodium fluoride solution. Contemp Clin Dent 2019;10:423-7

How to cite this URL:
Talwar M, Tewari A, Chawla H S, Sachdev V, Sharma S. Fluoride concentration in saliva following professional topical application of 2% sodium fluoride solution. Contemp Clin Dent [serial online] 2019 [cited 2020 May 26];10:423-7. Available from: http://www.contempclindent.org/text.asp?2019/10/3/423/280410




   Introduction Top


Professional topical application of fluorides for the prevention and progression of dental caries is carried out by dentists in dental clinics at the chairside as well as in community settings with an application frequency of 2–4 times a year. Fluoride availability in the oral environment is important for the prevention and reversal of early dental caries. In communities, where water fluoridation exists the use of professional topical fluorides has been restricted to individuals who are moderate and high risk to dental caries. However, in places, where there is no water fluoridation or there is suboptimal fluoride in drinking water and due to lack of awareness, there is limited use of fluoride dentifrice, in these situations, the regular professional topical application may be considered for schoolchildren at the chairside or in a field setting. Salivary fluoride is considered an important parameter to predict the effectiveness of topical fluoride agents.[1],[2] It has been proven that low levels of fluoride 0.03–0.5 mg/L in saliva are sufficient to effectively inhibit demineralization and enhance remineralization of enamel. Cycles of demineralization and remineralization continue throughout the lifetime of the tooth constantly exposing it to at risk of developing dental caries. The preventive effect of 2% sodium fluoride solution against dental caries has been reported.[3],[4],[5] Two percent sodium fluoride solution remains in contact with teeth for a shorter duration resulting in the formation of bonds in the superficial portion of the enamel.[6],[7] Maintenance of low levels of fluoride in saliva for long-term periods can control the carious lesion progression. Salivary fluoride levels in the range of 0.1–1 ppm are of clinical importance.[8] The present investigation was carried out to assess the fluoride concentration available in saliva following a 2% NaF professional topical application and evaluate the duration of availability of fluoride in saliva post 2% NaF professional topical application to establish scientific rationale for the frequency of use.


   Materials and Methods Top


The study was carried out in a community setting in 45 schoolchildren of Chandigarh, aged 7–15 years. The participants were residing in the hostel accommodation of the school. They were nontea drinkers and were using a nonfluoridated dentifrice with more or less similar dietary intake. Water fluoride of the area ranged from 0.34 ppm to 0.38 ppm of fluoride. Students undergoing orthodontic treatment and those with any medical history were excluded from the study. The written informed consent was taken from the children and their parents along with permission to carry out the study from the school authorities. Two percent sodium fluoride solution was prepared by dissolving 20 g NaF powder in 1000 ml of deionized water. On the day of application, baseline saliva samples were taken early morning upon rising (without the participants eating, drinking, or brushing their teeth) before exposing the participants to the topical fluoride agent. After collection of the baseline saliva sample, the participants brushed their teeth with a nonfluoride dentifrice, had breakfast, following which the 2% NaF solution was applied. The participants were made to sit upright in a chair in daylight, isolation was done with gauze pieces, and standardized small plastic brushes with plastic handles were used for the application of 2.5 ml solution/participant. After application, the solution was left in the mouth for 4 min. After the removal of the gauze (6 per participant, 2 on the lingual, and 2 on the buccal side of the lower jaw and 2 in the buccal vestibule of the upper jaw), spitting was not permitted. The participants were instructed not to eat or drink anything for 1 h. Postapplication unstimulated whole saliva samples were collected at 15, 30, 45, 60 min, before lunch (5 h), before dinner (10 h), and early next morning, i.e., 20 h. As baseline levels of fluoride in saliva after 20 h from the commencement of the experiment had not reached, a time schedule for the saliva sample collection at weekly intervals was chosen. Saliva samples were collected at weekly intervals up to a period of 1 month (four samples) and then after 3 months. These samples were of unstimulated saliva collected early morning from the participants upon rising. The participants were followed till the salivary fluoride levels approximated those at baseline (up to 3 months postapplication).

Estimation of fluoride in saliva

The collected saliva samples were transported within 30 min of collection to the Department of Dentistry at PGI, Chandigarh, and stored in a refrigerator at 4°C until the analysis.[9] The saliva samples were brought to room temperature and treated with total ionic strength adjustment buffer (TISAB) III (Orion Boston, MA, USA) buffer. To 10 parts of saliva, 1 part TISAB III buffer (5 ml for 50 ml of sample) was added in a plastic vial and shaken before fluoride estimation. The addition of TISAB to saliva samples was done to liberate free fluoride ions (i.e. to break the aluminum and fluoride-ion complexes and adjust the pH between 5 and 5.5). At a pH below 5.0, H + form complexes (HF, HF 2−) that interfere in fluoride estimation. Similarly, if the pH of the solution is above 7.0, there is interference by OH - ions during fluoride estimation. The AMS P507 Multichannel ion-analyzer with fluoride combination electrode (Orion model 94–09, 96–09 Boston, MA, USA) was used for the estimation of fluoride in saliva samples. The instrument was calibrated in incremental order, i.e., 0.01, 0.03.0.1, and 0.3–1 ppm with temperature remaining constant.

Statistical analysis

Data were analyzed using IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp. The normality of the data was tested at all-time intervals using the Kolmogorov–Smirnov test and box plot, and it was found to be nonnormal. All-time intervals were compared with baseline using the Wilcoxon signed-rank test, and a statistically significant difference was observed at all-time intervals compared to baseline (P = 0.0001).


   Results Top


Fluoride concentration in saliva increased above baseline, with peak at 15-min postapplication [Table 1]. Salivary clearance according to this study showed a biphasic pattern with a peak at 15 min followed by a rapid fall in 1 h, i.e., 60 min and a slow consistent decline over a 20-h period [Figure 1]. The fluoride concentration in saliva remained elevated above the baseline from 0.03 ppm to 0.231 ppm after 20 h. A weekly follow-up was decided upon, and it was observed that fluoride concentration remained elevated to 0.076 ppm up to 3 months postapplication of 2% NaF professional topical application [Table 2] and [Table 3].
Table 1: Mean and standard deviation of fluoride concentration in saliva (ppm)

Click here to view
Figure 1: Clearance curve of fluoride postapplication of 2% sodium fluoride solution

Click here to view
Table 2: Assessment of normality of the data (Kolmogorov–Smirnov test)

Click here to view
Table 3: Comparison of fluoride concentration in saliva at various time intervals postapplication of 2% sodium fluoride solution with baseline (Wilcoxon signed-rank test)

Click here to view



   Discussion Top


Salivary fluoride levels are considered important parameters to predict the effectiveness of fluoride agents.[1],[10] The preventive effect of 2% sodium fluoride solution against initial dental caries has been reported, although it remains in contact with teeth for a short duration resulting in the formation of bonds in the superficial portion of the enamel.[6],[7],[10] Saliva has remineralizing potential [11] that is enhanced in the presence of fluoride. Any elevation of salivary fluoride concentration may prevent enamel demineralization by increasing the degree of saturation of saliva, thereby promoting remineralization of early carious lesions. The prevention of demineralization has been observed at 0.1 ppm and at even lower levels of 0.014 ppm present continuously for 72 h. Salivary fluoride levels in the range of 0.1–1 ppm are of clinical importance (Heintze and Petersson 1979). The increase in fluoride concentration in saliva from 0.01 ppm to 0.1 ppm, i.e., 5–10 fold increase for prolonged periods may be effective for caries control.[12],[13] Saliva is an important source of fluoride for concentration in plaque.[2],[14] Salivary fluoride concentration shows a biphasic clearance pattern, an initial rapid phase lasting 60 min followed by a slower decline. Similar findings have been reported by (Duckworth and Morgan 1991) following fluoride dentifrice use.[15] Findings of this study show long-term fluoride retention compared to other studies which have been carried out in fluoridated communities. A possible explanation for this is that plaque binding sites are occupied by fluoride ions largely in communities with fluoridated water but not where water contains only traces of this ion.[16] The gradual increase in the salivary fluoride concentration may be due to a reservoir effect. Soft tissues such as oral mucosa, tongue, and plaque take up fluoride where it is bound and is released in ionic form during lowering of the pH.[2]

Socioeconomic status, patient education, diet, periodic clinical examination, community where the patient resides, water fluoridation and use of fluoride dentifrice all affect the caries preventive plan and prescription.[17] Dental caries was recorded for these participants according to Moller's index 1966[18] (PGI modification), no radiographs were taken. The severity was based on ≥4 open carious lesions (Grade 3, 4, and 6) + 11 decayed, missing and filled surfaces (DMFS )+ defs-high caries activity n = 8 participants; ≥2–3 open carious lesions (Grade 3, 4, and 6) or ≥5DMFS + defs moderate caries activity n = 23 participants; and ≤1 open carious lesion (Grade 3, 4, and 6) or ≤4 DMFS + defs low caries activity n = 13; no caries n = 1.

Considering that, out of 45 participants, 31 (8 + 23) participants belonged to the high and moderate caries activity for this population, the recommended application of 2% NaF solution is every 2–3 months, approximately 4 times a year. Certain population groups who do not have access to regular dental care may benefit from topical fluoride application even in a field setting in the community.


   Conclusion Top


Clinical practice in preventive dentistry should be based on evidence. Findings of this investigation in the population studied suggess that scientific rationale of frequency of application of professional topical 2% sodium fluoride solution is between 2 to 3 months which is 4 applications yearly.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
   References Top

1.
Margolis HC, Moreno EC. Physicochemical perspectives on the cariostatic mechanisms of systemic and topical fluorides. J Dent Res 1990;69:606-13.  Back to cited text no. 1
    
2.
Vogel GL. Oral fluoride reservoirs and the prevention of dental caries. Monogr Oral Sci 2011;22:146-57.  Back to cited text no. 2
    
3.
Mühlemann HR, Rudolf ER. Fluoride retention after rinsing with sodium fluoride and amine fluoride. Helv Odontol Acta 1975;19:81-4.  Back to cited text no. 3
    
4.
Galagan DJ, Knutson JW. The effect of topically applied fluorides on dental caries experience; report of findings with two, four and six applications of sodium fluoride and of lead fluoride. Public Health Rep 1947;62:1477-83.  Back to cited text no. 4
    
5.
Knutson JW, Armstrong WD, Feldman FM. The effect of topically applied sodium fluoride on dental caries experience; report of findings with two, four and six applications. Public Health Rep 1947;62:425-30.  Back to cited text no. 5
    
6.
American Dental Association Council on Scientific Affairs. Professionally applied topical fluoride: Evidence-based clinical recommendations. J Dent Educ 2007;71:393-402.  Back to cited text no. 6
    
7.
Cho MJ, Lee HL. A study on the effect of multiapplication of fluoride on enamel remineralization. J Korean Soc Hyg Educ 2001;1:125-32.  Back to cited text no. 7
    
8.
Heintze U, Petersson LG. Accumulation and clearance of fluoride in human mixed saliva after different topical fluoride treatments. Swed Dent J 1979;3:141-8.  Back to cited text no. 8
    
9.
Zero DT, Fu J, Espeland MA, Featherstone JD. Comparison of fluoride concentrations in unstimulated whole saliva following the use of a fluoride dentifrice and a fluoride rinse. J Dent Res 1988;67:1257-62.  Back to cited text no. 9
    
10.
Al Dehailan L, Lippert F, González-Cabezas C, Eckert GJ, Martinez-Mier EA. Fluoride concentration in saliva and biofilm fluid following the application of three fluoride varnishes. J Dent 2017;60:87-93.  Back to cited text no. 10
    
11.
Head J. A study of saliva and its action on tooth enamel in reference to its hardening and softening. J Am Dent Assoc 1912;59:2118-22.  Back to cited text no. 11
    
12.
Byeon SM, Lee MH, Bae TS. The effect of different fluoride application methods on the remineralization of initial carious lesions. Restor Dent Endod 2016;41:121-9.  Back to cited text no. 12
    
13.
Featherstone JD, Zero DT. An in situ model for simultaneous assessment of inhibition of demineralization and enhancement of remineralization. J Dent Res 1992;71:804-10.  Back to cited text no. 13
    
14.
Rolla G, Ekstrand J. Fluoride in oral fluids and dental plaque. In: Fejerskov O, Ekstrand J, Burt BA, editors. Fluoride in Dentistry. 2nd ed. Copenhagen: Munksgaard; 1996. p. 215-29.  Back to cited text no. 14
    
15.
Duckworth RM, Morgan SN. Oral fluoride retention after use of fluoride dentifrices. Caries Res 1991;25:123-9.  Back to cited text no. 15
    
16.
Whitford GM, Buzalaf MA, Bijella MF, Waller JL. Plaque fluoride concentrations in a community without water fluoridation: Effects of calcium and use of a fluoride or placebo dentifrice. Caries Res 2005;39:100-7.  Back to cited text no. 16
    
17.
Weyant RJ, Tracy SL, Anselmo TT, Beltrán-Aguilar ED, Donly KJ, Frese WA, et al. Topical fluoride for caries prevention: Executive summary of the updated clinical recommendations and supporting systematic review. J Am Dent Assoc 2013;144:1279-91.  Back to cited text no. 17
    
18.
Moller IJ. The clinical criteria for diagnosis of incipient carious lesion. Adv Fluoride Res 1966;4:67-72.  Back to cited text no. 18
    


    Figures

  [Figure 1]
 
 
    Tables

  [Table 1], [Table 2], [Table 3]



 

Top
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Add to My List *
* Registration required (free)  

 
  In this article
    Abstract
   Introduction
    Materials and Me...
   Results
   Discussion
   Conclusion
    References
    Article Figures
    Article Tables

 Article Access Statistics
    Viewed335    
    Printed38    
    Emailed0    
    PDF Downloaded66    
    Comments [Add]    

Recommend this journal