Dental Onlays: The Process From Start to Finish

by | Nov 22, 2018 | Uncategorized

Fillings or onlays: Which should you choose?

You would need a dental onlay when the cavity in your tooth is too big for a regular filling but not severe enough for a dental crown.

Dental onlays are one way to repair teeth damaged by cavities. They are custom-made restorations placed where the decayed dental tissue used to be. They have an external part that is bonded onto the chewing surface and sides of the outer tooth.

Like dental crowns, dental onlays protect the tooth from breakage and infection. Unlike crowns, onlays are designed to leave the structure of the tooth intact, which means minimal removal of the enamel. The process of putting in a dental onlay takes two dentist's visits. It goes like this:

How the dentist puts in dental onlays

For patients with medical conditions, the dentist takes precautions because the procedure of putting in dental onlays requires them to use a drill to remove decayed tissue in the tooth.

For people with conditions like a weak immune system or medical implants, the dentist will prescribe a protective course of antibiotics prior to the procedure.

Preparation of the tooth

During the first of two procedures, the dentist cleans the tooth and prepares its surface for the fitting of the dental onlay:

1. The dentist uses a topical anesthetic to numb the gum and injects the gum with an anesthetic to numb the tooth.

2. The dentist then makes a mold of the teeth before proceeding with the rest of the procedure. The impression is used to make a temporary dental onlay for the patient as they wait for a permanent one. At this point, the dentist also chooses the color of the permanent onlay, which should match the patient's teeth.

3. Using a rubber dam, the dentist isolates the tooth from the rest of the mouth.

4. Any existing restoration is removed from the tooth.

5. Using a drill or dental file, the dentist dislodges and removes decayed tissue from the tooth.

6. If a large part of the outer tooth structure has been removed, the dentist rebuilds the tooth. First, the dentist places small pins in the tooth. The pins act as frames to support the filling material that the dentist uses to rebuild the tooth.

7. The outer surfaces of the tooth are filed down to reduce the tooth's dimensions. This is done to make space for the onlay to fit over the prepared tooth. It will also ensure that all the teeth are the same height and have good spacing between them.

8. An impression of the prepared tooth is taken. It will be used to fabricate the onlay at a dental lab.

9. The dentist then places the temporary onlay onto the prepared tooth.

Fabrication of the onlay

At a dental lab, the permanent onlay is fabricated using the impression of the prepared tooth. The onlay is made in four steps:

1. Dental stone is poured into the impression of the prepared tooth and is left to solidify into a cast.

2. After the cast is tested and checked for imperfections, it is used to make a wax pattern that will be used in the sculpting of the permanent onlay.

3. Using the pattern, the dental onlay is fabricated using porcelain, metal alloy or whatever material the patient chooses.

4. The fabricated onlay is then polished and in the case of porcelain onlays, stained to match the color of the patient's teeth.

Fitting of the permanent onlay

The patient makes a second dental visit where the tooth is numbed and the temporary onlay removed. The tooth is then cleaned.

Next, the dentist bonds the onlay onto the tooth, seals the perimeter of the onlay and makes any adjustments necessary to prevent a bad bite. The onlay is polished, and the patient goes home with a fully restored tooth.

Dental onlays last

If you want to fill a cavity using a long-lasting treatment, dental onlays are a safe bet. They make the structure of the tooth stronger and can last more than 30 years. Dental onlays are worth every penny. When done by a skilled dentist, they have all the advantages of dental crowns without the downside of having to thin the enamel. 

Need a restoration?

Looking for dental onlays near the 85283 area? Call South Mountain Family Dental at (602) 438-9245.