Cosmetic Dentistry

Inlays and Onlays

        Inlays and onlays are indirect restorations used to restore teeth when optimal esthetics and strength are required by the type of dental case being restored or desired by the esthetic demands of the patient. Indirect restorations are those that are fabricated in the dental laboratory so the optimal esthetics can be achieved and the strongest longest lasting materials can be used, because these restorations are not restricted to what can be done directly in a patient’s mouth. This allows for a multiple number of materials and shades to be combined and fired to extremely high temperatures in a dental furnace, usually in excess of 2000 degrees Fahrenheit. The flexibility of the indirect restoration makes it a much superior restoration than the direct composite restoration that is done directly in the patient’s mouth, what most patients call a filling, in both durability (longevity) and esthetics.

Before        After

        Inlays and onlays also require multiple visits in the dental office before they are completed, unlike direct composite restorations that are completed in just one dental visit. At the initial restorative dental visit the dentist will remove and caries, dental decay, that is present in the tooth, establish the shape and size of the cavity preparation, place any base or other medicaments the clinical situation dictates, take an impression of the cavity preparation the adjacent teeth and the opposing teeth, and place a temporary restoration in the cavity preparation so that the patient can function comfortably until the final restoration is received back form the dental laboratory. Once the final inlay or onlay restoration is received back from the dental laboratory the patient is rescheduled for a second dental visit and the final inlay or onlay restoration is placed in the cavity preparation in the patient’s mouth. In the second visit the inlay or onlay restoration is chemically treated, acid etched and a chemical bond enhancer applied. The patient’s tooth is chemically treated, again it is acid etched with a different acid than the indirect restoration is etched with and a bonding agent applied to the tooth surfaces. Then a bonding luting agent or bonding cement is used between the indirect inlay or onlay restoration and the tooth. Dental luting agents or bonding cements come in a wide verity of colors or shades so that they will match the patient’s tooth and the inlay or onlay.

Before        After

        In the dental laboratory the laboratory technician will pour up a stone model from the dental impression that was taken of the patient’s mouth. This will enable the laboratory technician to very accurately reproduce the patient’s mouth in the laboratory. This model will very accurately represent the cavity preparation, the patient’s adjacent teeth and the patient’s opposing teeth. All of this information is critical to the laboratory technician in fabricating an indirect restoration that fits extremely well. The dentist will also send the laboratory technician pictures of the patient’s mouth, often with a reference shade guide so the laboratory technician can get an accurate impression for the colors required to match the patient’s natural teeth, along with the dentist’s impression of the colors required to match the patient’s teeth. The dentist will also instruct the laboratory technician in what material the inlay or onlay should be fabricated out of depending on the clinical situation in the patient’s mouth. Today there are a number of porcelains and other glass like materials that match the color, translucency, hardness and strength of natural tooth structure incredibly well and are improving all the time.

        Inlays on onlay as well as other indirect dental restorations are more expensive than direct composite restorations initially, but are more cost effective over time. Most direct composite restorations need to be replaced every five to seven years because they wear out and become discolored, while a laboratory fabricated indirect restoration can last a life time and has an expected average life span of twenty-five to thirty years. In most cases the inlay and onlay don’t fail the reason they need to be replaced is that the tooth structure around them becomes carious, has dental decay. Indirect dental restorations are therefore more cost effective over time and reduce the number of dental treatments a tooth will require over its life-time, which makes them the better dental bargain all around compared to direct composite dental restorations.