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Dental Onlay vs Crown - Your Dentist in Fort Lauderdale explains the difference

When dental decay or wear is too large for the remaining tooth structure to be properly supported by a regular dental filling, your Fort Lauderdale dentist may recommend an onlay or a crown.   The primary difference between these treatment options is the amount of natural tooth that is preserved.  When your dentist discusses with you which option to use, an important consideration is the amount of tooth structure missing due to decay or wear.

The following photo is an excellence example of various amounts of remaining tooth structure left due to decay.  Each of your natural teeth has pointed or rounded projections on its chewing surface called cusps.  Molars normally have four or five cusps, premolars have two and canine teeth have only one cusp.   When deciding whether to restore your tooth with a filling, an onlay or a crown,  your dentist's decision depends on whether one or more of the cusps need to be restored.  A crown is placed (as on the first tooth from left) when a large portion of the tooth has been lost due to decay or if the tooth is fractured.  The crown covers the entire remaining tooth giving it the most protection and strenghtening the remaining tooth.  An onlay can be placed when one or more cusps are lost or weakened while other cusps remain strong.  In this example, on the middle tooth, one cusp was removed due to decay and an onlay was placed to restore the remaining tooth.   The decay in the right most tooth in the photo below did not extend to the cusps and the tooth was restored with a white filling, or a composite filling.


A dental onlay, sometimes referred to as a three-quarter crown or partial crown, is a type of restoration between a dental filling and dental crown.  An onlay, usually made of porcelain or gold,  is used to restore your tooth when a dental filling will not be strong enough but enough of the tooth structure remains intact that a crown is not warranted.  Your cosmetic dentist on Commercial Blvd may suggest this conservative approach to repair your tooth if it has a large filling or if it has sustained damage due to decay or fracture.  An advantage of an onlay is that less of your remaining tooth structure is removed during preparation for the onlay compared to preparation for a crown.  The onlay is made to fill the space left when decay is removed and to cover the biting surface of your tooth.  A disadvantage of a dental onlay is that not all insurances cover this procedure. Onlays typically last around 10 years.


Crowns, sometimes called "dental caps," are placed both in restorative dentistry as well as cosmetic dentistry. A dental crown is a restoration that covers the entire tooth and offers the greatest protection and strength for your remaining tooth structure.  In cosmetic dentistry, crowns are placed to improve the aesthetics of your smile. One advantage of having a dental crown is that it is a commonly covered procedure by all insurance companies. Dental crowns can last between 5 and 20 years depending on your at home oral routine and regular visits to your dental hygienist for dental cleanings. 

Whether you need a dental filling, an onlay or a full dental crown, call Excellence in Dentistry at 954-928-1666. Dr. Nancy Rotroff and Dr. Gerard Wasselle provide the highest quality dental restorations for their patients in Fort Lauderdale and Lauderdale by the Sea. Our office is conveniently located at 2480 E. Commercial Boulevard between Bayview Drive and Federal Highway.  We are in network for many dental insurance companies.

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