Direct composite veneers–more commonly known as tooth bonding–is a simple but effective procedure for repairing a tooth by applying a composite resin that “bonds” to the tooth while covering up the cosmetic damage. It’s a quick, pain-free technique that requires little prep and usually no anesthesia and can be completed in a single visit.  

Here’s how the process works and what it can be used to treat…

What Can Bonding Be Used For?

Dental bonding is a simple way to fix dental issues that aren’t too serious from either a cosmetic or functional perspective. 

For example, it’s commonly used to fill in small cavities, which virtually everyone will deal with at some point in their lives.

Bonding can also be used to repair minor cracks and chips in teeth, to close gaps between adjacent teeth, and to lengthen short teeth so that the smile is symmetrical. 

Your dentist will determine if dental bonding can be applied to resolve any of these issues during a consultation.

Step 1: Preparation

Very little prep work is needed to get you ready for tooth bonding. 

The dentist may clean your teeth to make sure the area is free from plaque and tartar, but often this will have already been done as part of a routine cleaning appointment. 

If the dentist has identified a cavity that needs to be filled before being bonded, you may require anesthesia if the cavity will be drilled to remove decayed material. 

Other cases that would necessitate anesthesia include dramatic reshaping of the tooth to be bonded, or bonding work on a chip that’s near the tooth nerve, which could be painful if jostled during bonding. 

But in the majority of bonding sessions, anesthesia will not be necessary.   

Step 2: The Bonding Procedure

If you’ve ever done woodworking or coated a floor with epoxy, you know that roughing or etching the surface to be glued helps open up the pores and make a better attachment. 

The same is true with teeth, so the dentist begins a bonding procedure by roughing it. 

He may start by roughing the tooth with a fine-grit diamond bur or coarse paper, which creates an extremely thin layer of tooth debris on the enamel and the dentin beneath it called a smear layer. By fading out the etching as it approaches the edges of the tooth, the dentist can create a seamless transition from natural tooth to the bonding. 

He can then either remove the smear layer with a mild solution of diluted phosphoric acid, or use a bonding agent that penetrates the smear layer and incorporates it into the bond with the resin. 

If an acid solution is used, after 20 seconds it’s rinsed away. Teflon tape, also known as plumber’s tape, may be used on adjacent teeth to protect them from coming in contact with the solution.  

Next the dentist applies the bonding agent or “bonderizer” with a brush before curing it with LED light for 10-20 seconds. This thin layer of resin will ensure a firm hold between the enamel and dentin and the composite bonding material. 

There are many different bonding agents available on the market–your dentist may choose one that prioritizes reliability, speed, applicability with a particular etching technique, or other feature. 

Then the dentist will apply the composite resin to the tooth in a shade of white that color-matches your natural teeth. 

Some dentists will do this entirely by hand, while some will use a lingual stent, or a basic mold to assist them in crafting the shape of the bonded tooth. But because this stent isn’t customized to the patient’s mouth, there is still artistry involved in shaping the resin into a convincing replica tooth.

What Is Composite Resin?
The material used in a bonding procedure is made up of a mixture of plastic and glass combined into a putty-like resin through a process called free radical polymerization. The monomers used to create the resin are chosen based on their hardness, flexural strength, and resistance to water absorption and swelling, and ongoing development of new monomers continues to improve performance in these areas.   

Still, for all its impressive abilities to resemble natural teeth, it’s important to note that composite resin can’t be whitened, so once it’s applied, you would have to redo the bonding with a whiter shade to achieve a whiter color. This is why it’s recommended to have teeth whitening done before a bonding procedure if that is something you’re interested in.

The dentist will use the shape of the corresponding tooth on the opposite side of your mouth as a go-by to ensure symmetry with the bonded tooth. 

To achieve the desired shape, he’ll make fine trims and cuts to the resin to produce realistic contours and grooves in the tooth. This can even be done painlessly long after the resin has been hardened with a UV light or laser, so if he needs to, he can go back in at any point and make more refinements. 

The composite bonding is hardened with a UV light or laser.

The dentist may go through the process of adding resin and curing it several times if the repair is a significant one, as it’s too difficult to cure a large amount of resin all at once. 

The dentist also must pay attention to the translucency of your teeth and whether they are monochromatic or polychromatic, which he can mimic by layering the composite with different shades and using a wheel or brush to polish the tooth, and finishing with an aluminum oxide glaze. 

Very Few Risks

There are very few risks with dental bonding because it’s not surgery and only rarely involves anesthesia. You could theoretically have an allergic reaction to the bonding resin used, although this is very rare. 

However, it is known that while none of them contain the endocrine disruptor Bisphenol A in them directly, many dental composite resins in common use contain compounds that turn into BPA when they come in contact with saliva and/or contain BPA derivatives

But most experts believe the benefits far outweigh the risks, and studies show scrubbing and rinsing sealants and fillings after they’re applied removes up to 95% of the compounds that can become BPA.  

After the Procedure

Just as there’s very little pre-bonding activity that must be done, tooth bonding has virtually no after-care protocols that need to be followed. 

Unless you had anesthesia, you can immediately return to your normal routine of eating, working, driving, etc. You might have a little tooth sensitivity or different “mouth feel” for a couple days, but these will pass quickly.  

How Long Does Bonding Last?

The lifespan of your bonding will depend on several different factors. 

How well you take care of your teeth is probably the biggest factor, but where in the mouth you had bonding done can also make a difference. 

Brushing and flossing daily and visiting the dentist regularly can make bonding last longer, sometimes well over a decade, but on average bonding lasts five to 10 years.  

Keep in mind that bonding isn’t as tough as natural enamel and while it can chip or break, it’s just as likely to need replacement down the road due to staining or discoloration as breaking. 

Please visit our page on how long dental bonding lasts for more information. 

Learn More About Bonding at Bunker Hill Dentistry

As we’ve shown, the results of direct composite bonding can be affected by your dentist’s skill with resin. 

At Bunker Hill Dentistry, we have an experienced dentist who is also an artist, which means he’s able to transform your cracked or chipped tooth into a beautiful finished product that no one would ever guess is not 100% natural. 

View Our Bonding Services