Inlays and onlays are also known as ‘indirect fillings’ and are useful for repairing slight tooth decay damage. However they are both different and have different uses for different individual cases. Here we will look at the differences between the two.
What Are Inlays and Onlays?
Inlays and onlays as mentioned are both used to repair decay – specifically to fill cavities which are the slight holes on the inside of the teeth (the chewing surface). It is important to fill these to cover up exposed nerves, to prevent food from getting stuck, and to prevent further decay.
Both inlays and onlays are placed in one visit to the dentist and this makes them non-invasive and very rapid solutions. However there will be some associated pain and as such the patient will be given a local anaesthetic and often provided with nitrous oxide and oxygen. The decay on the tooth will also need to be removed before the inlays and onlays are applied.
These are not quite as permanent a solution as regular fillings, but can last several decades depending on the nature of the case as well as the material used. The materials they can be made from include: gold, composite resin, ceramics or plastic and they will normally be cemented into the cusps on the top of the teeth.
What Is the Difference?
The difference between inlays and onlays then is that an inlay is placed inside the cusp or the bumps on the top/bottom of the teeth. In other words it only covers a very small area and is placed essentially in the holes you can feel with your teeth. However onlays are slightly larger – larger than regular fillings in fact – and these cover the whole chewing area and overlap the edge of the teeth so that they cover slightly the outward and inwards facing surfaces. In some cases this will then mean that they also cover neighbouring teeth slightly. Onlays are similar to crowns and cover more of the tooth making them more extensive in terms of coverage than inlays, but will not always be necessary when the damage is only very minor in which case inlays will be used.