Fluorosis – Tooth staining caused by excessive fluoride intake.
What is dental fluorosis?
- Fluorosis is a type of permanent tooth stain that forms as a result of a child’s exposure to excessive systemic (internal) levels of fluoride during the time period when their teeth are forming.
- The high level of fluoride in the child’s blood serum disrupts the normal process of tooth enamel formation. As a result, areas of it are flawed by hypomineralization (a reduced amount of mineral content) and increased porosity.
- These changes in the enamel’s makeup also alter its appearance (pictures). – Color changes associated with fluorosis can range from chalky white to brown. Just isolated or widespread portions of a tooth may be involved. Tooth surface damage or pitting may occur. Usually, multiple teeth are affected.
Common sources of ingested fluoride include fluoridated toothpaste (either swallowed when brushing or eaten), and also beverages (water, juices, infant formula). A person’s systemic level of fluoride is cumulative in nature (meaning multiple exposures create an additive effect).
What does dental fluorosis look like?
With normal (unaffected) teeth …
- The tooth’s enamel will have a shiny, glass-like appearance.
- The tooth will also usually possess some degree of translucency. (Meaning light has the ability to pass into or through it.)
With affected teeth …
- The areas of fluorosis will have a dull chalky appearance due to an increase in their enamel’s opacity (loss of translucency).
- Some type of color alteration will be apparent too, ranging from a bright chalky white (most common) to brown. (See pictures below.)
What causes these changes?
The way fluorosis affects the appearance of a tooth has to do with the ways it has altered the composition of its enamel (reduced level of mineralization, increased porosity, increased fluoride content).
These changes affect both the color of the enamel and how it handles light (its degree of translucency), and possibly even its surface texture.
Fluorosis – Characteristics, examples, photos.
Slight to mild dental fluorosis.
This type of fluorosis pattern is referred to as “snow capping.”
a) Mild cases.
- The staining pattern involved is usually one where chalky-white lines, or opaque white patches or flecks, can be seen dispersed across a limited region of the tooth’s enamel.
- The staining is typically bilateral, meaning the same tooth on each side of the mouth displays a very similar pattern of discoloration (see illustration below).
- Any portion of the tooth may be the region affected. – When the staining is found right at the tooth’s biting edge, it’s often referred to as “snow capping.” (See picture.)
Severe dental fluorosis.
Extensive fluorosis staining is referred to as tooth mottling.
b) Moderate to severe cases.
- A greater percentage, or even all, of the tooth’s surface will display staining. Tooth surface abnormalities such as pitting may be evident too.
- Besides just chalky-white, severe cases may exhibit yellow, brown or even black discolorations.
Severe dental fluorosis.
The areas that are most affected have brown discoloration.
- Actually, and even with severe cases, when a tooth first erupts (comes through the gums) it’s areas of fluorosis will be white in color.
Then, due to the low mineral content and porosity of the affected areas, darker color staining will accumulate over time (due to the incorporation of metal ions into the enamel such as copper and iron).
- In severe cases, the tooth’s under-mineralized enamel may be fragile and therefore damaged relatively easily.
This might occur during events as simple as chewing hard or crunchy foods. People who clench or grind their teeth excessively may cause significant tooth wear.
Streaks of fluorosis frequently have formed during the same time period.
They lie at different levels because the teeth were at different stages of development at the time of the fluoride exposure.
c) Bilateral symmetry is the norm.
The explanation lies in the fact that the affected areas on matching pairs of teeth (left/right central incisors, lateral incisors, eyeteeth, etc…) were all at the same point of enamel formation when the exposure to the fluoride took place (see illustration).
However, the region of stain on different types of teeth can be expected to lie at different levels. That’s because at any point in time, some kinds of teeth are further along in their development (more fully formed) than others.
How severe can a child’s fluorosis be expected to be?
The extent to which fluorosis has affected any one child’s teeth will vary, according to a number of variables.
- The actual level of fluoride reached in the child’s blood serum will play a role. As will how long that status existed, and the number of repeat episodes that were experienced.
- Even after experiencing a similar fluoride exposure, each individual child will have their own personal level of risk for, and resistance to, fluorosis.
Governing factors include: the child’s genetic makeup and health status (malnutrition and renal insufficiency are known risk factors). Additional variables such as the child’s weight, level of physical activity and even their geographic altitude can also influence the level of staining that occurs.
- Since whatever effects that do take place do so during tooth formation (a point when the developing tooth is still encased in the jawbone), it’s impossible to know to what extent it has actually been affected until it has finally erupted.
▲ Section references – Nowak, Abanto
Treatments for fluorosis tooth staining.
a) Slight / Mild cases.
With cases where only minimal evidence of fluorosis is evident, no treatment is required if the person considers the appearance of their teeth acceptable. The integrity of the affected areas of enamel is seldom a concern.
b) Moderate and Severe cases.
In situations where the lesions caused by fluorosis are readily apparent and objectionable to the patient, a repair can be made by placing a dental filling (bonding), veneer or crown. Which type of restoration is deemed the most appropriate will simply need to be determined by the treating dentist.
- Bonding (dental composite) – This type of restoration tends to be most appropriate for situations where the extent of the fluorosis is somewhat limited in size. (Situations where just a portion or a few spots on each tooth require repair).
Since composite is able to bond directly to a tooth’s surface, the smaller the size of the lesion being corrected (both in terms of surface area and especially depth) the greater the likelihood that this option makes the absolute best choice.
Generally speaking, if some type of restoration must be placed (see minimally invasive alternatives below), bonding is the method of choice for making minor to minute tooth-colored repairs.
- Dental veneers – As compared to a composite restoration, porcelain veneer placement is generally chosen for cases where the extent of the fluorosis is comparatively greater (for example, a majority of the tooth’s surface).
Other considerations might be that for a particular case the treating dentist feels that a veneer will offer superior esthetics or longevity.
- Dental crowns – Both veneers and dental composite are bonded restorations, and as such require a region of normal/healthy enamel to be bonded to. (Remember, fluorosis is areas of porous, under-mineralized enamel).
Dental crowns don’t have this requirement. So in cases where the extent of a tooth’s fluorosis is very severe, placing a crown may be the only viable option that a dentist has to offer. Crowns also make the appropriate choice for cases where the structural integrity of the teeth being treated has been compromised by their condition and therefore requires strengthening.
c) Conservative treatments for Mild and possibly Moderate fluorosis.
Placing a restoration isn’t always the best solution.
A major drawback of having any type of restoration placed (bonding, veneer or crown) is that at some point in time it will ultimately require replacement.
This would be especially true for restorations placed relatively early in a person’s life, and those whose cosmetic appearance is of utmost importance. Restorations used to correct fluorosis would tend to fit both of these criteria.
You may have some minimally-invasive treatment options.
Your dentist may be able to offer one or a combination of the following “minimally invasive” procedures as a solution for your case. This term, or its synonym “conservative,” applies because compared to performing other procedures the tooth itself is little changed.
Advantages – The idea here is that nothing requires less maintenance over the long-term than a sound healthy tooth. So if your tooth with fluorosis meets that criteria, and its appearance can be corrected conservatively, then by far doing so makes the best treatment plan, not placing some type of restoration.
Disadvantages – As we discuss below, what sometimes comes with comparatively less invasive options is an outcome that’s less perfect. Or it may not be possible to know the treatment’s outcome beforehand. In either case, after undergoing the procedure you may still decide that restorations are needed to ultimately get the esthetic outcome you desire.
That’s not to say that conservative treatments never give a perfect result, because sometimes they do. You’ll simply have to rely on what your dentist tells you they feel is possible.
But for some people choosing one of these approaches is a compromise that’s selected because the value of a minimally altered tooth is understood and is important to them. And in light of that, a significantly improved, as opposed to perfect, cosmetic outcome is perfectly acceptable.
Option #1 – Teeth whitening treatments.
How fluorosis is treated via whitening treatments.
Because the body of the tooth is whiter, the areas of fluorosis staining are less obvious.
But even at short distances, results like these might be interpreted as quite normal by the eyes of others. And therefore an outcome that’s perfectly acceptable to the patient, especially considering the simplicity with which the transformation was accomplished.
Option #2 – Microabrasion treatments.
As its name implies, microabrasion technique involves a process where the stained surface of a tooth is abraded off.
The underlying problem.
Fluorosis blemishes lie in a tooth’s enamel layer. In some cases, the lesion itself may be confined to just a portion of the enamel’s full thickness.
With microabrasion technique, the surface layer of the enamel, and the imperfections it contains, are worn away using an acidic abrasive paste. The whole process isn’t terribly unlike an aggressive form of tooth polishing. (We discuss details about the procedure here.)
The end result is a tooth that’s been returned to its normal appearance, at the expense of some of its enamel thickness.
Probably the biggest problem associated with utilizing microabrasion is that the dentist never really knows for certain how deep in the enamel the fluorosis extends.
Since the dentist will always error on the side of safety (by not removing too much enamel), if the extent of the lesion is deeper than hoped only a partial rather than full resolution will be accomplished. A dental restoration, although a smaller one, may still need to be placed.
But in cases where the use of this technique has provided acceptable results, it offers the perfect solution. The tooth’s appearance has been restored. The amount of enamel it has lost should be inconsequential. No long-term maintenance of any kind is required.
Option #3 – Combined treatments.
It may be that neither teeth whitening or microabrasion treatments have been (or are expected to be) successful on their own. But using a combination of the two is able to produce acceptable results.
In most cases, the microabrasion procedure will be performed first, then the whitening treatments.
Option #4 – Resin infiltration.
This is a relatively new technique that may offer a conservative solution for mild to moderate fluorosis cases.
Using this procedure, a plastic resin is used to fill in areas of enamel porosity associated with the fluorosis. We discuss this technique’s use here as a repair for a similar type of enamel lesion.
Who’s at risk for fluorosis? – Answer: Young children.
What are the years of greatest concern?
Dental fluorosis only occurs when elevated levels of fluoride are ingested (swallowed) during that time frame when a child’s teeth are developing.
So once the crown portion of a tooth (the enamel-covered part that shows above the gum line) has completed its formation (a process that finishes long before the tooth’s root has completed its development), it’s no longer at risk.
Based on studies that have documented the usual time frames associated with tooth development, the most critical years for the risk of fluorosis lie between the child’s birth and age 6 to 7 years.
- In regard to permanent teeth that show, the greatest risk lies between the ages 1 and 4 years, with special emphasis on the period 20 to 30 months.
- Generally speaking, at around age 8 years a child would no longer be at risk.
▲ Section references – Abanto
The damage isn’t actually visible until later on.
As mentioned above, because fluorosis only forms during that period while the child’s teeth are in the process of forming (and therefore still lie embedded in the jaws), its effects aren’t visible until the affected teeth have finally erupted (broken through the gum line).
Permanent and/or baby teeth may be affected.
Fluorosis forms during tooth development, so any teeth that are forming at the time of the child’s elevated fluoride exposure may be affected. That includes both permanent (adult) and deciduous (baby) teeth.
Since deciduous teeth ultimately exfoliate (fall out), correcting their appearance usually isn’t an issue. But having baby teeth that show signs of staining is often an indication that the child’s permanent teeth will show similar defects too.
Fluorosis risk factors. / Prevention.
Studies have identified four fluoride sources that are commonly associated with a child’s risk for developing fluorosis.
They are: 1) fluoridated drinking water, 2) fluoride supplements, 3) topical fluoride (especially fluoride toothpaste, see below), and 4) formula prescribed for children. Additionally, commercially prepared (store-bought) foods and beverages sometimes play a role.
The list above reveals that with the widespread availability of fluoridated products combined with the implementation of municipal programs (water fluoridation infographic), it’s now easier than ever for a child to experience a high level of fluoride intake.
That means every child’s total exposure should be evaluated and monitored. Your dentist is in the best position to help you calculate and calibrate what their exposure/intake is and should be.
▲ Section references – Abanto
! A primary cause of fluorosis is swallowing toothpaste.
a) The underlying problem.
Small children, especially those younger than age 6, characteristically are not able to reliably spit out when brushing.
As a result, they may end up swallowing a large portion of the toothpaste that’s been placed on their brush. And if it contains fluoride, over time enough may be ingested that fluorosis forms.
- 1 to 3-year-olds may get up to 80% of their daily intake of fluoride from toothpaste. (de Almeida)
- It’s estimated that 2 to 3-year-olds ingest 48% of the amount of toothpaste dispensed, 4 year olds 42%, 5-year-olds 34% and 25% by 6-year-olds. The estimate for children between 8 and 12-years is around 10%. For adults it’s 10% or less. (SCHER).
b) Avoidance. / Prevention.
The following suggestions can help to minimize a child’s risk for fluorosis.
- Children should be given instructions about how to properly brush and rinse. They should be supervised when brushing so to help them form and practice proper brushing habits.
- In most cases, it’s the amount of product that’s used rather than the concentration of its fluoride that poses the greatest risk (Davies). Fluoridated toothpaste should always be dispensed by an adult, not the child.
Read your toothpaste’s instructions, generally only a small amount of toothpaste is needed. A common measurement for children is a dab the size of a green pea. For those younger than 3 years, just a smear or rice-size amount. Dispensing toothpaste the full length of a child’s toothbrush can correlate with an amount that’s many multiples of the proper amount.
- As a general rule, unfluoridated tooth cleansers should be used with children 2 years and under. Ask your dentist for their specific recommendation.
- Store fluoridated toothpaste out of the reach of children (some kids like the way it tastes and eat it).
- When purchasing fluoride toothpaste, look for one that has the American Dental Association’s (ADA) “Seal of Approval.” These products have been shown to be both safe and effective.
The fluoride content of commercially prepared foods must be monitored.
Bottled juices and juice-flavored drinks can be a source of high levels of fluoride. These products sometimes have a concentration that is significantly higher than the 0.7 ppm (parts per million) considered appropriate and optimal.
▲ Section references – Nowak
Page references sources:
Abanto AJ, et al. Dental fluorosis: Exposure, prevention and management.
Davies RM, et al. The rational use of fluoride toothpaste.
de Almeida BS, et al. Fluoride ingestion from toothpaste and diet in 1- to 3-year-old Brazilian children.
Dean JA, et al. McDonald and Avery’s Dentistry for the Child and Adolescent.
Nowak AJ, et al. Pediatric Dentistry: Infancy through Adolescence.
SCHER. Opinion on critical review of any new evidence on the hazard profile, health effects, and human exposure to fluoride and the fluoridating agents of drinking water.
All reference sources for topic Tooth Decay.