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Interproximal Cavities: The Inside Story

March 12th, 2026

Time to brush! So, you make sure you gently brush the plaque off the outside surfaces of your teeth. You want to present a gleaming smile to the world, after all. And you make sure to brush the inside surfaces as well, because who wants to feel a fuzzy patch of plaque every time their tongue hits their teeth? And, naturally, you remember to clean the tops of your molars, because those crevices make them more cavity-prone than any other surface.

Done? Not quite!

You might be surprised to learn that no matter how well you’ve brushed all the visible surfaces of your teeth, you’ve left quite a bit of enamel untouched—the adjoining, or touching, surfaces of the teeth that sit next to each other.

You’ve probably noticed that your bristles can’t . . . quite . . . reach all the enamel between your teeth (especially between your molars!) when you’re brushing. This means that food particles and plaque have an easier time sticking around. And when the bacteria in plaque are left undisturbed, especially with a banquet of food particles available, they produce acids which gradually eat away at the enamel covering our teeth, creating a cavity.

Here’s where we work in some specific dental vocabulary. “Interproximal” means between the adjoining, or touching, surfaces of the teeth. And an interproximal cavity is a cavity that develops on one of those side surfaces of your teeth.

  • Preventing Interproximal Cavities

Fortunately, prevention is about as basic as it can be—brushing and flossing effectively. Dentists recommend brushing for two minutes at least twice a day and flossing once each day. While most of us are good about keeping up with brushing, sometimes that daily flossing is more a goal than a reality.

But it’s flossing which really does the trick when it comes to interproximal cleaning. If you floss correctly, food particles and plaque are removed from between the teeth and around the gum line—places where bristles just can’t reach.

When you wear braces, though, flossing isn’t quite so basic. Getting that floss just where it needs to be in between brackets and wires and in between teeth can be a challenge!

The good news is there are many products designed just to make flossing easier while you’re in orthodontic treatment:

  • Floss threaders are flexible hoops that help you thread floss behind your wires easily.
  • Precut floss strands use a stiff tip at one end for threading floss through wires.
  • Interproximal brushes are tiny, cone-shaped brushes which can fit between your teeth and braces for precise cleaning.
  • Water flossers eliminate floss altogether, using a pulsing stream of water to clean between and around teeth and braces.

During your next visit to our Chicago office, Dr. Iwei Huang can give you tips on how to use any of these tools effectively for cleaner teeth and cleaner braces.

Preventing cavities on the exterior surfaces of your teeth is probably pretty much automatic by now, but don’t forget the potential for stealth decay! If we find signs of erosion on the sides of your teeth, or if your hygienist lets you know that you’ve got a lot of interproximal plaque buildup, work with your dental team to make sure “interproximal cavity” doesn’t become a working part of your dental vocabulary.

Can Toothpaste Repair Tooth Decay?

March 5th, 2026

It seems like the ads are everywhere these days—repair your enamel and reverse tooth decay with a tube of toothpaste! Are these claims too good to be true? Let’s dive into the science of tooth decay—how decay develops and how (and if!) it can be reversed.

Teeth can stand up to the powerful pressures of biting and chewing because over 95% of our enamel is made up of minerals. Calcium and phosphate ions in our teeth bond to form a crystal structure called hydroxyapatite. Because of the strength of this crystalline design, tooth enamel is the hardest substance in our bodies, even stronger than our bones. 

But bones, like most other parts of our bodies, are living tissue, which means that they can create new cells to replace old or damaged cells. Tooth enamel can’t regenerate new cells to repair itself. This means that when a cavity has made a hole in the tooth, the enamel can’t grow back. And, while enamel structure is very strong, it’s also vulnerable to damage—specifically, damage from acids. 

Our teeth are exposed to acids throughout the day, whether they are acids created by plaque bacteria or the acidic foods and drinks we consume. Acids dissolve mineral bonds, stripping calcium and phosphate minerals from the enamel and leaving weak spots in the tooth surface. This process is called demineralization. Demineralization is the first stage of tooth decay.

The good news? Our bodies are designed with a built-in defense mechanism to prevent demineralization from causing lasting damage. All through the day, saliva helps wash away acids in the mouth and bathes our teeth with new calcium and phosphate ions. These ions bond with the calcium and phosphate in our enamel, restoring enamel strength. This protective repair process is called remineralization. 

Now for the bad news. In the tug of war between demineralization and remineralization, saliva can only do so much. If your diet is heavy with acids, if you don’t brush away acid-producing plaque bacteria regularly, if you eat a lot of the sugars and starches which feed plaque bacteria, the remineralizing effects of saliva can’t keep up with the demineralizing effects of acids.

The first visible sign of demineralization is often a white spot on the tooth where minerals have been stripped from enamel. Studies have shown that enamel-strengthening toothpaste can be effective in this very first stage of tooth decay. Toothpastes which advertise enamel repair generally contain one or more of these ingredients:

  • Calcium Phosphate
  • Hydroxyapatite
  • Fluoride 

Toothpastes with calcium phosphate or hydroxyapatite contain calcium and phosphate minerals, the building blocks of tooth enamel. Studies have suggested that these minerals can replace the calcium and phosphate ions stripped from enamel. These toothpastes may or may not contain fluoride, which is something you should discuss with your dentist before deciding on a specific toothpaste.

Fluoride toothpastes remineralize enamel—and more! Fluoride ions are attracted to the tooth’s surface, and, when fluoride ions join with the calcium and phosphate ions there, they form fluorapatite. Fluorapatite crystals are larger, stronger, and more resistant to acids than hydroxyapatite crystals. And, once bonded with tooth enamel, fluoride attracts the calcium and phosphate ions in saliva to remineralize the teeth more quickly. 

Why consider enamel-repair toothpaste? 

Once enamel is gone, it’s gone for good. If excess demineralization isn’t treated, a weak spot on the tooth surface will continue to erode, growing bigger and deeper until it becomes a hole in the enamel. This is a cavity, and your dentist will need to treat and repair your tooth to prevent the cavity from growing and potentially exposing the tooth’s pulp to bacteria and infection. 

If you wear braces, you want to be especially careful about excess demineralization. Because it can be hard to brush and floss effectively with braces, white spots and discolored patches are a common concern for those with braces, especially on the enamel around brackets.  

Talk to Dr. Iwei Huang at our Chicago office about which toothpastes can help restore a healthy balance between the ongoing cycles of demineralization and remineralization when you have braces. While tooth-repair toothpaste can’t fix cavities, these products can often strengthen demineralized enamel and reverse this earliest stage of tooth decay.

The Twin Block Appliance

February 26th, 2026

Orthodontic treatment involves a lot more than just straightening your teeth. For a healthy smile, your bite must be healthy as well! This means that the upper and lower jaws need to fit together properly and comfortably.

If your bite is out of alignment because of jaw misalignment, orthodontic treatment can help correct the shape and position of your jaws with devices called functional appliances. These appliances are most often used for young patients whose bones are still growing, and are designed to treat malocclusions, or bite problems.

Common malocclusions such as overbites and overjets can occur when the upper teeth protrude further than they should, or the lower jaw is positioned too far back, or both. The Twin Block appliance can be used in such cases to help move your lower jaw and teeth into alignment with your upper jaw.

Why “Twin”? Because the Twin Block appliance is two separate pieces, each made of wire and smooth acrylic. Both pieces are crafted to fit precisely over your upper and lower arches and can be adjusted as your treatment progresses. The top plate can also be adjusted, if necessary, to widen the upper palate.

Why “Block”? Acrylic blocks cover the biting surfaces of several of your upper and lower teeth. These blocks fit together like a 3D puzzle. When you bite down, the upper blocks interlock with the lower blocks, pushing the lower blocks forward just a bit before you can bite down completely. Over time, bit by bit (and bite by bite), the Twin Block appliance advances your lower jaw and teeth to create a balanced, comfortable bite.

For the quickest and best results, you should wear your Twin Block appliance as directed. It’s made to be worn comfortably while you sleep, eat, and otherwise go about your day. (It’s a good idea to check with our Chicago orthodontic team to see about removing it when you’re active, especially for swimming and contact sports.) When it’s time to brush, the Twin Block appliance is removable. This means that you can clean your teeth and your appliance easily.

And, while it’s made to work hard for you, it’s not indestructible. Don’t expose your appliance to heat or hot water, as the plastic may warp. Use the cleaning methods we recommend. Finally, when your appliance is out of your mouth, keep it in its case! You don’t want your appliance to end up carefully wrapped in a napkin in the nearby recycling bin. Or, even worse, in your dog’s mouth instead of yours.

The Twin Block appliance might fit together like a puzzle, but there’s nothing puzzling about how to achieve your best and fastest results. Your success really depends on you. Follow Dr. Iwei Huang and our team’s advice, wear your appliance as directed, and you’ll be on your way to a healthy, comfortable bite and an attractive, confident smile!

Xylitol: A significant factor for improving your oral health

February 18th, 2026

Xylitol is a naturally occurring sweetener found in tree bark, plants, fruits, and vegetables. The human body also produces it in small amounts. It looks and tastes like sugar, so as part of a health regimen, most people require no willpower to use it.

Xylitol is safe (approved by the World Health Organization) because only a small amount is needed for health benefits. With a glycemic index of seven, it is safe for diabetics. It has less than three calories per gram and 40% fewer calories than other carbohydrates. If eaten in extremely large amounts too quickly, it has a laxative effect in humans.

Tooth decay happens when bacteria in your mouth consume the sugars you eat. When you eat food that contains ordinary sugar, it gives energy to the bacteria on your teeth, allowing them to multiply and start making acids that destroy the enamel on the teeth.

Since xylitol is a natural sweetener derived from the fibrous parts of plants, it does not break down like sugar, so it helps maintain a neutral pH level in the mouth. Xylitol also prevents bacteria from sticking to the teeth because they are unable to digest it. That is how it protects the teeth from cavities.

With xylitol, the acid attack is diminished. With less bacteria and acid, your teeth stay healthier. The frequency of xylitol ingestion is important: aim for five grams a day, or one gram every three hours.

Studies of xylitol use as either a sugar substitute or a small dietary addition have demonstrated a dramatic reduction in new cavities. It has also stopped and even reversed some existing cavities. This effect is long lasting and possibly permanent. Low cavity rates persist even years after the trials have been completed.

Xylitol needs to be one of the first ingredients in a product to be effective. It is convenient and easy to use. You can find it in health food stores and specialty grocery stores. Xylitol can be delivered to your teeth in chewing gum, tablets, or even candy and mints.

It also comes in toothpaste, mouth rinse, baby oral wipes, gel and pacifiers, nasal wash, dry mouth spray, a granulated form for cooking, granulated packets to add to drinks, and commercially prepared foods. It can replace sugar on a one-to-one ratio.

Sweet rewards in xylitol are good for the body and the teeth! If you have specific questions please feel free to contact Gold Coast Orthodontics. We look forward to seeing you soon!