Dental inlays and onlays, otherwise known as custom made fillings, are restorations used to repair mild and moderate decay, cracked or fractured teeth where the damage is not big enough to require a crown. This allows the dentist to conserve more of the patient’s original tooth structure. Inlays and onlays are durable, hard-wearing materials which can last over 10 years. Dental inlays are also used when an old filling needs to be replaced.