Fillings are a common way to repair teeth that are affected by tooth decay. Tooth decay is caused by plaque, a sugary diet, poor oral hygiene and happens over an extended period of time. When decay gets through the hard enamel layer of the tooth, it can progress rapidly and reach the nerve of the tooth, causing pain and eventually tooth death. It is critical to treat tooth decay as quick as possible to protect the nerve and stop decay from progressing. Patients often feel a cavity or hole in their teeth often caused by tooth decay. They can develop symptoms such as cold or hot sensitivity and pain as well as food being stuck within this cavity. In many instances we are able to detect a developing cavity (through an x-ray or via visual inspection) and quickly address it with a tooth filling. The other important function of a filling, is that a filling can also be used to replace the decaying tooth structure. The procedure is typically simple and easy where in the dentist will often anesthetise or numb up the area with local anaesthetic, remove the decay and clean the tooth leaving it decay free, and then fill the space with a tooth coloured restorative material typically called a composite resin restoration (white plastic filling). In the past dentist were restricted to silver fillings which often required over prepping the tooth in order to have sufficient retention and bulk to withstand the forces generated in the mouth. As technology and new materials have developed dentist have an array of restorative materials that not only have an advantage by being matched to the tooth colour, but also requires minimal preparation only confined to the decayed area. The aim is to preserve healthy tooth structure and minimise trauma to the health of the tooth.