Pil Son Dental

Cosmetic Dentistry

White Fillings

White fillings have become the standard when it comes to fillings on the front teeth, and in many offices, in the back teeth as well. Their major advantages, that they can blend into the natural teeth and absence of mercury (see silver fillings) means that many patients have come in specifically to have older fillings replaced with white fillings.

What are they?

White fillings are made of composite resins, also called plastic! This particular kind is engineered for use in your mouth. It is basically composed of long strands of polymers that are free-flowing, so that the dentist can pack and mold it to your teeth. They then shine an intense blue light on the material to harden it. The light activates single binding units that begin to link all the strands together, making the material very rigid. Isn't science wonderful!

Today

While composite resins have been around for over 30 years, the technology has constantly evolved, and today's resins can mimic most natural tooth structure with incredible accuracy. We are understanding more and more about this versatile material and just how long it lasts. Today's resins have an average lifespan approaching that of silver fillings, and so are increasingly used in all types of restorative situations.

Should you Replace those Old Silver Fillings?

This is a question that is often asked, and the answer can vary depending on the situation. In general, however, I tend to err towards the conservative. Removing an old silver filling inevitably results in removal of more natural tooth structure as well, resulting in a bigger hole and a weaker tooth overall. Silver fillings have a long track record of durability, and are perfectly safe, so unless the patient is absolutely insistent on their removal, I always recommend leaving them in place. If it chips or a cavity develops necessitating their replacement, then a while filling can be placed.

Crowns

"You need to get a crown on that tooth." Hmm, you think to yourself, is he just trying to pad the bottom line here, or do I really need this crown? Well, here is a rough guide to the criteria dentists go through to determine the necessity for a crown.

Indications for a Crown

First of all, a crown is a porcelain or metal cap, or sleeve, that fits over the tooth and essentially protects it from fracture. It's like fitting a reinforced band around a fragile wooden post to make it stronger. Why would a tooth need to be reinforced? Well, there are several reasons:

• Root canal on a back tooth (see Afterwards on root canal section)
• There is a large filling increasing the risk of fracture
• You have just come in with a fracture in your tooth already
• Esthetics (lots of large, ugly fillings on your tooth)

Large fillings essentially scoop out the dentin (the softer, supportive tooth material under that thin layer of enamel), which increases the risk of fracturing the overlying enamel. An unfortunate bite into those tasty toasted almonds can mean a quick trip to the dentist!

Types of Crowns

As mentioned above crowns can be made from 2 main groups of materials: metal, porcelain, or a combination of the two (porcelain fused to metal - PFM). While metal crowns have fallen out of favour for obvious esthetic reasons, it should be noted that they have advantages which porcelain has yet to duplicate. These include:

• Metal crowns do not have to be as thick, so not as much tooth structure needs to be ground down
• They are very good at adapting to the margins of the tooth, so there is less chance of open gaps
• They are very strong and not as brittle, so they won't chip like porcelain sometimes can.

Porcelain fused to metal is a compromise. While metal margins will ensure a good fit, the porcelain will allow a natural look to the crown. However, in very esthetic areas, like the front teeth, PFM crowns can look dull, or flat, without the translucence of natural teeth.

Today, porcelain crowns can be fabricated with a base of zirconia, a type of metal that is white and quite strong, enabling us to make esthetic crowns that can bear the force of chewing in the back teeth, without compromising on esthetics. They also look very natural in the front as well!

Veneers

You've seen those bright white smiles on TV, but can't seem to duplicate them even after bleaching. What gives? Well, chances are those actors are sporting nice white veneers over their natural teeth. So, what are veneers, and how do you get them?

Veneers are thin porcelain coverings that are bonded onto the front part of your tooth. Unlike crowns, porcelain veneers require the removal of only a thin layer of enamel (approximately 0.3mm to 0.5mm) on the front surface or the tooth to allow space for the veneer. In fact, depending on the position of the teeth, it may even be possible to forgo tooth removal completely before placing a veneer! Veneers work by bonding to the tooth surface both chemically and through microretention. This means that the bond strengths of veneers are about the same as the structural integrity of the tooth itself. In fact, there have been cases when failed veneers have been due to the tooth breaking, not the failure of the bond.

Veneers are useful as conservative treatment for:

• Gap closures
• Misaligned teeth
• Colour changes

It should be noted that the same procedures can be performed with white fillings, and will look just as good. The only downside with white fillings is that they do not last last long, and the colour does tend to change over time. Still, they will generally hold for five or more years, depending on usage.

Tooth Bleaching

Tooth bleaching has become one of the most popular ways to brighten and lighten one's teeth, and there has followed an exponential growth of advertisements and products out on the marketplace. So, how does the smart consumer (that's you!) figure out what's what, and what's not? Well, here is a primer on what to look for.

How Does It Work?

When you read bleaching or whitening labelled on toothpaste, strips, gels, brushes........gum(!?), it generally involves a product that does one of two things: either the teeth are oxidized with peroxide, or the product contains abrasives that remove surface stains from your teeth.

Abrasives

This method is exclusively found in toothpastes, and generally labelled whitening. Toothpaste in itself is a mild abrasive (composed of silica ie. glass, fluoride, and fillers), but the whitening label is placed on toothpastes with stronger abrasives. While it will be better at surface stain removal, care should be taken in their use, as there is an increasing prevalence of patients with gum recession, and these toothpastes can exacerbate that condition.

Some of these toothpastes also contain peroxide (look for the ingredient carbamide peroxide or hydrogen peroxide), but they are present in very low doses that it's difficult to see how much bleaching they could actually do.

Peroxides

Everyone has that one friend who is constantly changing his or her hair colour. Brunette one day, blond the next. Well, the product that he/she uses is peroxide, the very same used in tooth bleaching!

Hydrogen peroxide's tooth bleaching properties were first discovered because they are used as an antiseptic as well. Peroxide was prescribed as a rinse to control bacterial levels in patients with gum disease, and it dentists noted it's effects on lightening teeth as well. Nowadays, peroxides can found in over the counter (OTC) products and through your dentist. They work by oxidizing the staining compounds, changing their shape and making them more reflective to light.

You may have noticed that the products offered at the dental office are significantly higher in cost. Why does it cost so much more with your dentist, anyways?

The reason for the higher cost is because they simply work better. Peroxide's bleaching effects are dependent on two factors: concentration, and duration of contact with teeth. The higher the concentration, and the longer it stays on your teeth, the better it will work. There's just one problem. Higher concentrations of peroxide can actually burn your gum tissue, a side effect most are unwilling to suffer for (except hollywood actors). Thus, over the counter products have a limit in terms of concentration. Also, because OTC products are made for one size fits all, the peroxide has a tendency to leak out and get diluted by saliva, limiting it's duration of action.

At the dentist's office, there are two ways to get your teeth bleached: with a take-home kit, or have it done at the office. With the take-home kit, the dentist fabricates a custom tray that snugly fits your teeth. This way, the concentration of the bleach can be increased as the gel will be less likely to leak out, and it stays longer on your tooth.

In-office tooth bleaching makes use of the highest concentrations of bleach available, as the dentist will ensure full coverage of your gums. This way, your teeth will be bleached in the shortest amount of time possible.

Which method you choose depends on how much you want to lighten your teeth. The OTC products will work, but may not lighten your teeth as much as the products offered at the dentist's office.

Contraindications

While tooth bleaching is a safe procedure with many years of use and few side effects, there are some situations where bleaching is not recommended:

• Very sensitive teeth
• Oral pathology (ulcers), xerostomia (no saliva flow)
• Children
• Pregnancy/Lactation
• Exposed Dentin