Your dentist may be giving you more fillings than you need.
|A recent study
led by Wendell Evans at the University of Sydney supports growing evidence
that early tooth decay, before a cavity forms, can often be arrested and
reversed with simple
treatments that restore minerals in the teeth,
rather than the more typical drill-and-fill approach.
controlled trial followed 19
dental practices in Australia for three years,
then researchers checked up on the patients again four years later. The
result: After seven years, patients receiving
treatment needed on average 30% fewer fillings.
“This is quite important,” Mary Hayes, a clinical spokeswoman for the
Dental Association, says about the study,
published in December in the journal Community Dentistry and Oral
Epidemiology. “We have traditionally taken a surgical approach, removing
decay and replacing it with a filling,” says Dr. Hayes, a dentist in
Chicago. “You’re changing the paradigm to give ground to therapeutic
Tooth decay, or caries, is caused by bacteria that thrive
on sugars in the mouth and produce acids. Left in contact with a tooth, the
acids draw out minerals, creating microscopic pores. Decay progresses
slowly, and it may take years for a full-blown hole, or cavity, to form;
until that point, it can still be reversed. Mineral-containing saliva is
constantly working to replenish the teeth, and
fluoride aids remineralization.
After a filling, more than 60% of people will return to
the dentist with new decay within the next two years.
In the study, patients in the experimental group with early decay received a
fluoride varnish to
the site. Dentists also gave those patients fluoride
varnish preventively two to four times a year, and encouraged them to
brush well and avoid sugary snacks between meals.
Tooth decay, or caries, is caused by bacteria
that thrive on sugars in the mouth and produce
acids. Left in contact with a tooth, the
acids draw out minerals,
creating microscopic pores. Decay progresses
slowly, and it may take years for a full-blown hole, or
cavity, to form; until that point, it can still be reversed.
Mineral-containing saliva is constantly working to
replenish the teeth, and fluoride aids
After a filling, more than 60% of people will return to the dentist with new
decay within the next two years, says John Featherstone, dean at the University
of California, San Francisco, School of Dentistry.
“Two-thirds of the population. That’s huge,” Dr. Featherstone says. “So you need
to build into the
treatment plan a therapeutic regimen.” He says
dentistry’s traditional drill-and-fill response to tooth
decay is similar to a doctor who, upon seeing a patient with a red,
swollen arm, recommends cutting the arm off.
treatments to arrest tooth decay that researchers
have investigated is Xylitol 1, a
natural sweetener used in some candies that has been shown to help prevent
bacteria from making the acids that cause tooth
decay. Prescription antibacterial rinses seem to
help but need further study, researchers say. For biting surfaces prone to
decay, plastic sealants applied by a dentist
prevent nutrients that would feed bacteria from
getting into grooves on tooth surfaces.
The advantages of fewer fillings go beyond
avoiding the dreaded anesthetic injection and
drill. Fillings don’t
last forever and eventually need to be replaced, says Mark Wolff, chair of
cariology at New York University College of Dentistry.
Each successive filling is going to be bigger than
the last, progressively weakening the tooth. “The key is avoiding the first
one,” he says.
Dr. Wolff recalls a time his two children came home from college, one with
four areas of decay and the other with one. “I looked at the X-rays and was
quite horrified,” he says. “They’d gone off to college with not the slightest
evidence of decay. We put them on fluoride, a calcium-containing toothpaste, and
Xylitol,” he says, and the teeth
remineralized over the next two years. “Neither of
my children have any fillings,” he says.
An excessive amount of fluoride is toxic,
but research has shown that in the amounts used in dentistry and found in water
is safe and helps prevent cavities, Dr. Wolff says.
There is a substantial body of research supporting
remineralization as a
treatment for early tooth decay, and little
opposition in the
dental profession, says Margherita Fontana, a
professor of cariology at the University of Michigan
School of Dentistry. Tradition, however, has been an obstacle to
widespread use of the
treatment. “For older generations [of dentists], it
just feels wrong to leave decay and not remove it,”
Dr. Fontana says. “That’s how they were trained.”
Reimbursement is another obstacle. Insurance
typically covers application of fluoride varnish
in children, but not adults. The cost ranges from $25 to $55, according to the
Dental Association’s Health Policy Institute.
treatments also generally aren’t covered.
Dr. Featherstone says he advises patients at high risk for
decay to seek preventive
treatment. “For $100 a year you can have the
therapy and save yourself a crown for $1,000,” he says. Over-the-counter
fluoride rinses also provide some benefit. “If
you have new decay every so often, you’re high
risk, it’s as simple as that,” says Dr. Featherstone. According to the
National Institutes of Health, 20% of the U.S.
population gets 60% of all caries.
In a study, Dr. Featherstone and two colleagues, Benjamin Chaffee and Jing
Cheng, looked at the effectiveness of nonsurgical therapies for tooth
decay in a retrospective analysis of more than
2,700 patients’ records at the
dental clinic at UC, San Francisco. All patients
were at high risk for tooth decay.
The findings, published in September in the journal BMC
Oral Health, showed patients who took home
anti-caries agents at two or more
dental visits had 20% to 40% fewer new
decayed teeth over 18 months.
Dr. Featherstone led a randomized clinical trial of 231 adults, with about
half of them treated by dentists prescribing both
antibacterial and fluoride
treatments for any tooth decay before a
cavity had formed. The rest of the patients were
treated by dentists who continued their usual care. The need for
fillings after two years in the new
treatment group was 24% less than in the regular-treatment
group, according to the study, published in 2012 in the journal
1 Some research concludes thta XYLITROL simply
allows the saliva to circulate with the associated chewing.
Will Dentists help you grow new
BBC Tiffanie Wen 22 September 2016
- We may never evolve to grow a third set of teeth, but that hasn’t stopped
scientists from attempting to find a way to replace
extracted teeth with new, live replacements. One lab at
King’s College London has successfully implanted
bio-teeth into mice. Using gum tissue from humans and tooth forming cells
in mice, they were able to grow teeth with dentin
and enamel in mice. “What’s incredible is that the researchers can implant this developing tooth germ and it’s able to
re-orientate itself to form and recruit blood vessels from surrounding tissue
to make a live tooth,” Tucker says.
One of the challenges of using the therapy in humans, she says, comes from
culturing stem cells in-vitro, which tends to
make them lose their potency.
- Other recent approaches have focused on finding ways to get our teeth to
heal themselves. Ruchi Sahota, a dentist in
California and a spokesperson for the
American Dental Association, suggests visualising the anatomy of a tooth
like an apple. “They have a thin enamel shell, like the skin of an apple, that
protects the inner core, which is the dentin of the tooth. And just like the
seeds of an apple, we have the nerve of our tooth,” she said. “A cavity tends
to form in the enamel. When it gets into the dentin, you need to fill it at
the dentist. When it gets to the nerve, that’s
when you need a root canal.”
- A company called Reminova
is already working to bring a new approach to market. Also based on research
King’s College London, the technique uses painless
electric currents to encourage re-mineralisation of the enamel
healing tooth decay at the earliest signs of
- Other approaches use the cells that are in our teeth to heal cavities
that have already penetrated the enamel, by
stimulating the creation of dentin, the calcified tissue that makes
up the inner portion of our teeth. Recent research published in the journal
Translational Medicine for example, found that treating exposed tooth
pulp in rats with low-power laser light before filling
the cavity could induce stem cells to
create dentin in the tooth.
- In another approach, researchers from the
University of Nottingham and Harvard University
developing a therapeutic biomaterial that can work to heal a cavity, and
intervene before a root canal is necessary. The material can stimulate a
particular type of stem cells in the pulp
tissue to interact with other material that forms a new kind of
“This material can be injected in contact with pulp tissue and hardened with
UV light to form a plastic,” says Adam Celiz, a
postdoctoral fellow that is working on its development. “The native cells
interact with the plastic and differentiate into a different kind of cell
that produces dentin. So we’re hoping to
restore that dentin layer to return vitality to the tooth, which means
the pulp tissue wouldn’t have to be removed by a root
Researchers discover new natural tooth repair method
using Alzheimer's drug
Published on January 9, 2017
A new method of stimulating the renewal of living stem cells in tooth
pulp using an Alzheimer's drug has been discovered by a team of researchers
at King's College London.
Following trauma or an infection, the inner, soft pulp of a tooth can
become exposed and infected. In order to protect the tooth from infection, a
thin band of dentine is naturally produced and this seals the tooth pulp,
but it is insufficient to effectively repair large cavities.
|Currently dentists use man-made cements or
fillings, such as calcium and silicon-based products, to treat these larger
cavities and fill holes in teeth. This cement remains in the tooth and fails
to disintegrate, meaning that the normal mineral level of the tooth is never
However, in a paper published today in Scientific
Reports, scientists from the Dental Institute at King's College London
have proven a way to stimulate the stem cells contained in the pulp of the
tooth and generate new dentine - the mineralised material that protects the
tooth - in large cavities, potentially reducing the need for fillings or
The novel, biological approach could see teeth use their natural ability
to repair large cavities rather than using cements or fillings, which are
prone to infections and often need replacing a number of times. Indeed when
fillings fail or infection occurs, dentists have to remove and fill an area
that is larger than what is affected, and after multiple treatments the
tooth may eventually need to be extracted.
As this new method encourages natural tooth repair, it could eliminate
all of these issues, providing a more natural solution for patients.
Significantly, one of the small molecules used by the team to stimulate
the renewal of the stem cells included
Tideglusib, which has previously been used in clinical trials
to treat neurological disorders including Alzheimer's disease. This presents
a real opportunity to fast-track the treatment into practice.
Using biodegradable collagen sponges
to deliver the treatment, the team applied low doses of
small molecule glycogen synthase kinase (GSK-3)
to the tooth. They found that the sponge degraded over time and that new
dentine replaced it, leading to complete, natural repair.
Collagen sponges are commercially-available and
clinically-approved, again adding to the potential of the treatment's swift
pick-up and use in dental clinics.
Lead author of the study, Professor Paul Sharpe from King's College
London said: "The simplicity of our approach makes it ideal as a clinical
dental product for the natural treatment of large cavities, by providing
both pulp protection and restoring dentine.
"In addition, using a drug that has already been tested in clinical
trials for Alzheimer's disease provides a real opportunity to get this
dental treatment quickly into clinics."
Cavity Prevention is key
Of course, dentists will tell you that preventing cavities from forming in
the first place is the key to your dental longevity, starting with good oral
hygiene—brushing twice a day with fluoridated toothpaste, flossing once a day
and making regular trips to the dentist – and eating the right kind of foods.
“The most important food and thing for us to
keep in mind in terms of prevention is water
– especially fluoridated water,” says Sahota.
“Not only does the fluoride help mineralise and regenerate
tooth structures that may have become infected by a cavity, the physical motion
of drinking water helps to flush away food, bacteria and any debris that may be
stuck in your teeth as well.” She adds that dairy
is also great because it’s high in calcium and that
lean protein helps strengthen and
Even if we can rebuild this material in our mouths, we still
have to fend off a modern menace in our industrialised diets – refined
sugar. That’s because bacteria secrete acid
when it breaks sugar down, and that acid can cause decay
in our teeth.
So what type of candy is best avoided? Sahota says hard
candies like lollipops are especially bad since they give you a constant
exposure to sugar, while sticky candies get stuck in your teeth for long periods
At least she has good news for the chocoholics among us.
“Chocolate after lunch or dinner is a better choice than a lot of other candy
because it can get flushed out more easily. So go ahead and enjoy a bite after
If you don’t like going to the dentist, you’re not alone. Most
people have some anxiety about visiting the dentist, with one study in the
that 24% of adults feared the dentist. Moreover, significant amounts of people
who fear the dentist
avoid visiting until they really need to. That could help explain why
92% of American adults have tooth decay in their permanent teeth.
But there is good news on the horizon as well—recent research
also suggests that we might soon be able to refill the
holes in our teeth with healthy, living tissue, giving our permanent teeth a
Compared to other species, you may think we humans are
extraordinarily unlucky to have to depend on the same set of adult teeth for the
majority of our life. Shark enthusiasts are
familiar with the fact that sharks have unlimited sets of teeth during their
lifetimes. Galeophobes in particular might be terrified to learn that sharks
have rows of baby teeth underneath the skin waiting to replace the functional
ones, and shed and replace teeth as often as every three weeks, causing experts
to believe that the sea floor is littered with the teeth of sharks.
So if sharks, and most reptiles
and amphibians can replace their teeth over a lifetime, why do humans and most
mammals only get two sets of teeth?
Abigail Tucker, a professor of development and evolution at
King’s College London says that there is a trade-off between the complexity of
the teeth and the amount of sets the species gets. Since
mammals have the ability to chew, meaning they can grind their teeth
sideways (think of the movement a cow or
horse makes) we have developed complex sets of
teeth with multiple cusps, the bumps and mounds that define the shape of our
teeth. While our pointy canine teeth (cuspids) each have only one cusp, our
premolars (bicuspids) each have two cusps and our molars each have four or five
“The complexity is linked to diet, with bamboo eaters having
the most complex teeth,” she says. “Something like a giant
panda or a bamboo eating lemur have complex
back teeth with lots of cusps so they can really chew and grind the hard tissue.
So their teeth look similar even though they’re completely unrelated to [other]
There are other fascinating examples of animals with unique
Piranhas have teeth that are fused together to make large teeth that
resemble a type of sharp knife. When they shed teeth, they lose an entire
quadrant all at once, and rely on the other three quadrants to survive while the
new teeth come in.
While mammals are typically restricted to two sets of teeth –
a set of deciduous teeth and a set of permanent teeth – some mammals have
retained the ability to create more teeth or have evolved to have the ability
Manatees for example keep forming new teeth in the back their mouths over
the course of their entire lives.
Other animals only get one set of teeth, but they continuously
grow, including the aye aye lemur and
rodents like rats and
mice. “Rodents and
rabbits typically have a stem cell population at
the base of the tooth that keeps growing dentin and enamel. It’s an adaptation
to the hard foods that they’re eating,” says Tucker.
It’s unlikely that humans will ever evolve to have more than
two sets of teeth, since evolution requires that differences influence whether
or not offspring survive. But it is true that we are still evolving in a way –
experts believe that fewer and fewer people are now getting
wisdom teeth, the third
molars that arrive in early adulthood, when our jaw is fully grown.
“We’re cooking our food and it’s more tender so there’s no need to have the
third molar. In addition, our jaws are getting smaller so there’s less space,”
Tucker says. “Because of that we’re seeing a higher percentage of people who are
missing their third molars. About 20% of the population doesn’t have