According to (GPT-9) the action of pouring or injecting a flowable material into a refractory mold. The object formed is also referred to as “a casting”. There are various steps of fabrication of a simple full metal crown. Casting failures of alloys in dental technology should be the exception, not the rule. They have to be detected in time and associated with possible causes. For the experimental part base metal alloys single tooth restorations were achieved using the conventional lost wax process for casting in order to be evaluated. Some casting defects obtained during the experimental part are exemplified: incomplete castings, absence of the castings, voids, distorsions, nodules, porosities. Selecting the appropriate casting techniques for each alloy and dental restoration and accurate following of the technologycal steps are essential to avoid casting defects.