Composite fillings a combination of resins and fine particles designed to mimic the color of natural teeth. Composite resins need to be bonded to the tooth surface to allow for adhesion. Inlays and onlays are indirect dental restorations, which means they are made outside of your mouth in a laboratory. An inlay or onlay is usually used when a cavity is too large for a simple filling.

Thus, Inlay is a ceramic dental restoration used for restoring natural dental crown when only the upper surface of the tooth is damaged, and it cannot be restored by a filling either cast into shape with gold or milled into shape with porcelain, whereas Onlay is a ceramic restoration is used for bigger dental crown damages, where along with the upper surface of the tooth we need to restore the lateral surface as well.

They are more resistant to fractures and damage than traditional cavity fillings, have the ability to improve the natural aesthetic and appearance of teeth. Besides them, it develops the natural aesthetic and appearance of teeth. They are stain-resistant and may depend on the patient’s cavity and rupture risk, they can last up to 30 years.
First, if there is an existing filling in your tooth, your dentist will remove it prior to placement. So, cavity filling removal is done. Then, a mold is taken of the cavitated or damaged tooth. So, impression of the tooth is done by inlay or onlay mold with custom-made. Then, inlay or onlay is being prepared, a temporary filling is placed to seal the cavity. After the restoration is made, you will set up one more appointment with us to have the inlay or onlay placed.
The process of caring for inlays and onlays is very simple and does not require careful maintenance routines. Brush and floss regularly to keep your tooth’s health in shape. 
Inlay and onlay have a substantially longer life span than a composite filling and combined with quality oral hygiene they can last a long time.
We will completely anesthetize the area, before eradicating decay and damaged tooth material. If you do experience mild discomfort after the procedure, over-the-counter pain relievers should take care of it.