Onlay Restorations

What is an Onlay?

An onlay restoration is a custom made filling made of composite material, gold, or tooth-coloured porcelain. An onlay is sometimes also referred to as a partial crown. Porcelain onlays are made by a professional dental laboratory and is permanently cemented onto the tooth by your dentist.

Onlays are essentially identical to inlays with the exception that one or more of the chewing cusps have also been affected and need to be included in the restoration.

What have an Onlay?

Porcelain onlays are popular because they resemble your natural tooth. Onlays can be utilized to conservatively repair teeth that have large defective fillings or have been damaged by decay or trauma. Onlays are an ideal alternative to crowns (caps) because less tooth structure is removed in the preparation of onlays.

As with most dental restorations, onlays are not always permanent and may someday require replacement. They are highly durable and will last many years, giving you a beautiful long lasting smile.

Reasons for onlay restorations:

  • Broken or fractured teeth
  • Cosmetic enhancement
  • Decayed teeth
  • Fractured fillings
  • Large fillings

What does getting an onlay involve?

An onlay procedure usually requires two appointments. Your first appointment will include taking several highly accurate impressions (moulds) that will be used to create your custom onlay and a temporary restoration.

While the tooth is numb, the dentist will remove any decay and/or old filling materials. The space will then be thoroughly cleaned and carefully prepared, shaping the surface to properly fit an onlay restoration. A temporary filling will be applied to protect the tooth while your onlay is made by a dental laboratory.

At your second appointment, your new onlay will be carefully and precisely cemented into place. A few adjustments may be necessary to ensure a proper fit and that your bite is comfortable.

You will receive care instruction at the conclusion of your treatment. Good oral hygiene practices, a proper diet, and regular dental visits will aid in the life of your new onlay.

Are amalgam (silver) fillings safe?

Over the years there has been some concern as to the safety of amalgam (silver) fillings. An amalgam is a blend of copper, silver, tin and zinc, bound by elemental mercury. Dentists have used this blended metal to fill teeth for more than 100 years. The controversy is due to claims that the exposure to the vapor and minute particles from the mercury can cause a variety of health problems.

According to the Australian Dental Association (ADA), up to 76% of dentists use silver containing mercury to fill teeth. The ADA also states that silver fillings are safe and that studies have failed to find any link between silver containing mercury and any medical disorder.

The general consensus is that amalgam (silver) fillings are safe. Along with the ADA’s position, the Center for Disease Control (CDC), the World Health Organization, the FDA, and others support the use of silver fillings as safe, durable, and cost effective. The U.S. Public Health Service says that the only reason not to use silver fillings is when a patient has an allergy to any component of this type of filling. The ADA has had fewer than 100 reported incidents of an allergy to components of silver fillings, and this is out of countless millions of silver fillings over the decades.

Although studies indicate that there are no measurable health risks to patients who have silver fillings, we do know that mercury is a toxic material when we are exposed at high, unsafe levels. For instance, we have been warned to limit the consumption of certain types of fish that carry high levels of mercury in them. However, with respect to amalgam fillings, the ADA maintains that when the mercury combines with the other components of the filling, it becomes an inactive substance that is safe.

There are numerous options to silver fillings, including composite (tooth-colored), porcelain, and gold fillings. We encourage you to discuss these options with your dentist so you can determine which is the best option for you.

What can be done about old unattractive or discoloured fillings?

Most of us have fillings in our mouths that date back many years and some may have even been placed during our childhood. These fillings may now be old, dark, and unattractive, making us feel self-conscious when we smile, laugh, and talk. Old fillings are not only unattractive, they may also be defective. When a filling is old, the margins (space between the tooth and filling) may eventually open and allow bacteria and food debris to enter, potentially causing dental decay.

Your dentist can check your fillings and evaluate if they are defective and need replacement. Also, if you simply want to replace fillings that are unattractive, you and your dentist can decide which ones should be replaced first and what replacement options would best suit you. There are many state-of-the-art dental filling materials and procedures available today that are quick, painless, and cost effective for replacing old, unattractive or defective fillings.

Options for replacing old, unattractive, or discolored fillings:

Composite (bonding) fillings – These are tooth-colored fillings that can be closely matched to the color of your existing teeth. They are particularly well suited for use in front teeth or visible parts of teeth and are one of the best ways to improve the health and beauty of your smile.

Crowns (Caps) – These types of restoration are used when a tooth is too damaged and cannot be repaired with a filling or other type of restoration. A crown is a covering that encases the entire tooth surface restoring it to its original shape and size. A crown protects and strengthens the remaining tooth structure and can be made of gold, porcelain, and other tooth-colored materials.

Inlays/Onlays – These restorations are custom made fillings. They can be made of composite resin, porcelain or gold and are made by a dental laboratory and placed by a dentist. Inlays/onlays are usually best for the posterior chewing surfaces of teeth and are utilized to conservatively repair teeth that have large defective/unattractive fillings or have been damaged by decay or trauma.

Porcelain veneers – Used primarily in the front teeth, veneers are very thin shells of tooth-shaped porcelain that are individually crafted and permanently cemented to the front surface of teeth. They are a great solution for fixing discolored, pitted, shipped, malformed, or slightly crooked teeth. Veneers are also used if you have unwanted spaces. Veneers are very durable, natural looking, and do not stain. This makes veneers a very popular solution for restoring a smile impaired by old, unattractive fillings.

As you can see, there are various options for replacing old, unattractive fillings. These treatments will provide strong, natural, and long-lasting replacement solutions to enhance the health and beauty of your smile.