<P> Restorative materials include dental amalgam, composite resin, porcelain, and gold . Composite resin and porcelain can be made to match the color of a patient's natural teeth and are thus used more frequently when aesthetics are a concern . Composite restorations are not as strong as dental amalgam and gold; some dentists consider the latter as the only advisable restoration for posterior areas where chewing forces are great . When the decay is too extensive, there may not be enough tooth structure remaining to allow a restorative material to be placed within the tooth . Thus, a crown may be needed . This restoration appears similar to a cap and is fitted over the remainder of the natural crown of the tooth . Crowns are often made of gold, porcelain, or porcelain fused to metal . </P> <P> For children, preformed crowns are available to place over the tooth . These are usually made of metal (usually stainless steel but increasingly there are aesthetic materials). Traditionally teeth are shaved down to make room for the crown but, more recently, stainless steel crowns have been used to seal decay into the tooth and stop it progressing . This is known as the Hall Technique and works by depriving the bacteria in the decay of nutrients and making their environment less favorable for them . It is a minimally invasive method of managing decay in children and does not require local anesthetic injections in the mouth . </P> <P> In certain cases, endodontic therapy may be necessary for the restoration of a tooth . Endodontic therapy, also known as a "root canal", is recommended if the pulp in a tooth dies from infection by decay - causing bacteria or from trauma . In root canal therapy, the pulp of the tooth, including the nerve and vascular tissues, is removed along with decayed portions of the tooth . The canals are instrumented with endodontic files to clean and shape them, and they are then usually filled with a rubber - like material called gutta percha . The tooth is filled and a crown can be placed . Upon completion of root canal therapy, the tooth is non-vital, as it is devoid of any living tissue . </P> <P> An extraction can also serve as treatment for dental caries . The removal of the decayed tooth is performed if the tooth is too far destroyed from the decay process to effectively restore the tooth . Extractions are sometimes considered if the tooth lacks an opposing tooth or will probably cause further problems in the future, as may be the case for wisdom teeth . Extractions may also be preferred by people unable or unwilling to undergo the expense or difficulties in restoring the tooth . </P>

Area of tooth having least resistant to caries