The three-dimensional printing systems commercially available for dentistry are already capable of producing dental restoration devices more efficiently, accurately, and precisely than those made by traditional methods. Such a system can already print out in about fifteen minutes one unit of dental inlay or of artificial crown ready for a dentist to install in the patient the device was customized for. Nevertheless, different kinds of risks with a certain period of time, from short to long term and with severities from painful to lethal still exist among the processes starting from photographing a patient and diagnosing him/her to decide the most appropriate type of restoration device, and as well as to designing, producing, and installing the device. In Taiwan practicing any one of the professional works in the aforementioned processes requires licenses issued by the Ministry of Health and Welfare. This article categorized the types of aforementioned works as those of 'the dental laboratory works' and of 'the practices of medicine.' Practicing business of the former type bears the strict liabilities imposed by the Consumer Protection Act. A trader who injures a patient when practicing business shall bear no-fault liability in tort for damages and additional punitive liability with the level of severity varies with seriousness of the trader's fault. Practicing business of the later type bears the duties imposed by the Physicians Act, the Medical Care Act, and the Civil Code. A natural person and legal person who injure a patient when practicing business shall bear fault liability in tort for damages and presumed fault liability in tort for damages. Furthermore, the Civil Code imposes the following two types of joint liabilities for both types of practicing: the employer shall be jointly liable to make compensation for any injuries which the employee has wrongfully caused to the rights of another in the performance of his duties, and if several persons have wrongfully damaged the rights of one another, they are jointly liable for the injury arising therefrom. This article also analyzed and discussed different types of potential damages which might happen during any of the aforementioned processes, and different associated liabilities for damages caused by different natural persons and legal persons when they legally and illegally conduct different types of work. With the results analyzed and discussed by this article, hopefully, the dental professionals and institutions in our country could evaluate more clearly the potential benefits and legal liabilities for damages resulting from the use of three-dimensional printing systems in dental restoration.