direct filling as metal inlays are more superior in strength. It is also indicated when placement of direct restoration may be challenging to achieve satisfactory parameters (shape, margin, occlusion). They are usually reserved for larger cavities as tooth conservation is paramount in current practice and small cavities can be restored with direct composites instead. Onlays are indicated when there is a need to protect weakened tooth structure without additional removal of tooth tissue unlike a crown, e.g. restoring teeth after root canal treatment to give cuspal coverage. It can also be used if there is minimal contour of remaining coronal tooth tissue with little retention. Contraindications Poor Oral Hygiene Contraindications to providing Onlays and Inlays include plaque and active caries. It is important to ensure adequate oral hygiene before providing any indirect restoration as failure to manage the caries risk of an individual may result in recurrent caries. Caries risk is defined as “a prediction as to whether a patient is likely to develop new caries in the future”. The restoration itself does not alter the risk, which allows subsequent caries to develop around the indirect restoration placed. This may be caused by plaque retentive features of the restoration, or if the restoration is poorly bonded to the tooth. However, in the main the subsequent caries around a restoration is because the caries risk has not been reduced. Reducing the patients risk of further disease prior to treatment provides predictable results and helps prevent further restorative procedures.1 Parafunctional habits and heavy occlusal forces Inlays and Onlays are contraindicated in patients with parafunctional habits and heavy occlusal forces. A Parafunctional habit refers to abnormal functioning of oral structures and associated muscles, for example patients who clench or grind their teeth. Occlusal forces are greater on molars when compared to premolars. Evidence (Fuzzi and Rapelli) has shown greater failure of Onlays and Inlays in molars than premolars over an 11.5 year period. The most common cause for failure was porcelain fracture. To ensure longevity it is beneficial to avoid heavy occlusal forces. If a cuspal coverage onlay is required porcelain should be used as cuspal coverage with composite is contraindicated. Patients under 16. Indirect restorations are contraindicated in patients under 16 as the pulp chamber is still large and wide dentinal tubules increase the stress on the pulp. When preparing a cavity to retain an indirect restoration there is a risk of