INAC PROJECT'13

HELLO! WELCOME TO OUR BLOG :)

INAC PROJECT'13

Project Title:

Fluoride Concentration in Various Brands of Toothpaste

What Is It About?

Toothpaste that contains fluoride can help to prevent cavities. However, too much fluoride might not be good for our health.

This blog will talk about the pros and cons of using fluoridated toothpaste, and also on how fluoride concentrations of various brands of toothpaste are determined.

Conclusion

Monday, 29 July 2013

Fluoride is important in dentistry because of its ability to inhibit dental caries. It is incorporated into various products such as mouthwashes and toothpaste etc for human use. Thus it is crucial to determine the fluoride content level in these products as it will affect the public health.

The method of using Fluoride Ion Selective Electrode to determine the fluoride concentrations in various brands of toothpaste is simple and inexpensive, but may not be readily available in undeveloped or developing countries. This may cause the problem of inaccuracy results or no analysis when other less sensitive instruments/methods are used for determination of fluoride concentration.

Discussion

According to the National Agency for Food and Drug Administration and Control (NAFDAC) and Standards Organisation of Nigeria (SON), the recommended permissible levels of fluoride for adult toothpaste is between 825-1250ppm, while for paediatric toothpaste is between 425-625ppm.

Point 1

The NAFDAC and SON are organisations in Nigeria.

The toothpaste samples are manufactured from different countries.

Thus it is highly possible that different countries have different recommended permissible levels of fluoride for both paediatric and adult toothpaste.

Point 2
- There may be errors from the procedures which will cause inaccuracy in the analysis.
- The concentration of fluoride in toothpaste depends on various factors:
- Presence of ingredients which react with the fluoride to form insoluble compounds and thus affect the analysis of fluoride content.

- Inappropriate storage could lead to hydrolysis of free fluorides especially for samples that contain Sodium monofluorophosphate which hydrolyses to free fluoride and phosphate ions.

Point 3

Samples 3, 4 and 5 could have been exposed to temperature as high as 32 degrees celsius which could have led to degradation of some of these sample.

Results

The results table from the orignal scientific paper.
The highlighted ones are the ones we will be looking at.

To make it easier for you to see, we have created a table.

For adult toothpaste, Sample 1 and 2 has sufficient fluoride levels as the total fluoride content is within the range given by NAFDAC and SON.

Sample 3 and 4 has insufficient fluoride content. Their total fluoride content is much lower than the minimum level of 825ppm.

For paediatric toothpaste, both samples did not conform to the approved standard.

Sample 5 has total fluoride content of 349.105ppm which is lower than the minimum level of 425ppm for paediatric toothpaste.

Sample 6 has total fluoride content of 726.19ppm which is higher than the maximum level of 625ppm.

Risk Assessment

Limitations of The Method

There are several limitations for the Ion Selective Electrode method.

Interference from other ions in solution

Ionic strength of the solution reducing the measured activity relative to the true concentration at high concentrations

Potential drift

Materials and Methods

List of Materials

Orion Bench Top pH/ISE meter with fluoride ion-selective electrode(ISE)
Analytical-reagent grade chemicals
Distilled water
Sodium fluoride (NaF; USP reference standard)
Na4EDTA.2H2O tetra sodium ethylene diamine tetra acetic acid
Sodium hydroxide
Sodium acetate tridydrate
Concentrated HCl
6 toothpaste samples (Sample 1, Sample 2, Sample 3, Sample 4, Sample 5, Sample 6)
Desiccator (an airtight box or jar containing a desiccant, used to dry chemicals and protect them from the water vapour in the atmosphere)
Plastic volumetric flask
Plastic funnel
Plastic beaker
Stirrer

Methods (Chemicals Preparation)

1. Prepare 1000µg/ml Fluoride stock solution. Dry Sodium fluoride (USP Reference Standard) for 4 hours at 150°C and then cool it in a desiccator before use. Store the fluoride stock solution in a plastic volumetric flask.

2. A first stock standard solution of approximate F- concentration of 100ppm was prepared from which 1, 5, 50ppm working standards were made for the standardization of the ISE.

3. A check standard of 5ppm was then prepared from a second 100ppm stock standard.

4. Ionic strength(IS) diluent was prepared from 100g of Na4EDTA.2H2O tetra sodium ethylene diamine tetra acetic acid 15g of sodium hydroxide and 100g of sodium acetate tridydrate in a volume of 1000ml.

5. The pH of the IS diluent was adjusted to pH7.25[± 0.03] using concentrated HCl. When the IS reagent is used, the concentration of fluoride rather than its activity is measured.

Methods (Sampling)

6. 6 samples of toothpaste (both adult and paediatric) from different manufacturers and countries are selected in this experiment.

7. Accurately weigh 5g of Sample 1 into a 150ml plastic beaker and add 39.0ml of water.

8. Add 11.0ml of concentrated HCl. Cover the beaker and stir for at least 1 hour.

9. Cool the solution to room temperature and then transfer the mixture to a 250ml plastic volumetric flask with a plastic funnel.

10. Dilute mixture to mark with the NAIS Diluent.

11. Repeat Steps 7 to 10 for the other 5 samples.

**THINGS TO NOTE**

Check the pH of the sample prepared. The pH value should fall within 0.5 unit of that of the 5ppm working standard solution. The sample must be re-prepared if its pH is not within the range of 6.5 to 8.0.

The reading (R) in ppm for each sample was determined in duplicate with the ion-meter and the total fluoride concentration in ppm was calculated using the formula:

[F-] = R x 250/W

Where [F-] is the total fluoride concentration (ppm)

R is the reading for sample off the instrument (ppm)

W is the weight of sample (g)

Selected Method For This Task

The method we have selected to determine the fluoride content in the various brands of toothpaste is the...

Ion Selective Electrode

Photo of ISE

Simple Schematic Diagram of ISE

It measures the activity of an ion in a solution by measuring the electric potential formed across a membrane when the electrode is submerged in the solution.

It is...

- Sensitive to fluoride

- Unaffected by sample colour & turbidity

- Relatively inexpensive and simple to use

- Wide concentration range

Introduction

Thursday, 18 July 2013

http://www.imaginenation.org/sites/default/files/inline-images/dental_health_day.jpg

Fluoride (F-) is an important anion present in various environments, clinical and food samples. In many countries, fluoride is purposely added to toothpastes in 0.1% (1000 ppm) concentration as sodium monofluorophosphate (MFP) (Na₂PO₃F) , Tin difluoride (SnF₂) or sodium fluoride (NaF).

Iodent Fluoride

Sensodyne

Colgate PRO Clinical White

In order to determine fluoride concentrations in various samples, very sensitive methods have to be used. Although there are many methods that can be used to determine fluoride levels, the most recent one is the ion-selective electrode (ISE) method.

In this study, the fluoride concentrations of 6 samples of toothpastes were determined using a fluoride ion selective electrode (F-ISE). Despite the claimed role of fluoride in preventing tooth decay, it can also react with other ingredients in toothpaste and therefore is unavailable to perform this role. Hence, the purpose of this article is to determine the concentrations of fluoride in toothpastes so that we can ascertain whether the fluoride concentration obtained from sample analysis conform to the permissible values given by the World Health Organization (WHO) so that people would not use toothpastes that contain fluoride concentrations which harms them instead.

The Pros and Cons of Using Toothpaste that Contains Fluoride

Tuesday, 9 July 2013

Most of us know that fluoride helps to prevent dental cavities. But do you know that too much fluoride will cause adverse health effects on our body?

Many different brands of toothpaste sold in the market currently contains fluoride. However, only certain brands of toothpaste will contain fluoride, others fluoride-free.

Toothpaste with fluoride content

Toothpaste without fluoride content

Why do some companies manufacture toothpaste with fluoride while some don't?

This brings us to the main part of this post -- The Pros and Cons of using toothpaste with fluoride content.

The PROS:

Fluoride toothpaste

Aids in preventing dental decay by preventing bacteria in plaque to generate tooth-weakening acids
Helps to re-mineralize the teeth in the areas affected by the teeth-weakening acids
Keeps the tooth enamel sturdy by thwarting the loss of crucial minerals from the enamel

The CONS:

Too much fluoride causes discoloured and crumbling teeth
Fluoride increases the absorption of aluminum in the brain. Aluminum is what is found in the brains of patients with Alzheimer’s
Excess fluoride has had detrimental effects on the musculoskeletal and nervous systems. This has lead to limited joint mobility, muscular degeneration, ligament calcification, and neurological deficits
Men who are exposed to fluoride in the long term will develop a higher chance of suffering from bone cancer.

Consumers will choose whether they want to use toothpaste with fluoride content or not, after considering the benefits and impacts of fluoride toothpaste. Hence companies will manufacture different types of toothpaste for them.