Abstract
In preparation of complete denture fabrication, it is an important work for dental technicians to precisely recreate the original maxillomandibular relation assessed through dentist's examination and diagnosing by mounting and produce a prosthesis that allows its application only with a little occlusal adjustment. However, it is known that mounting with dental plaster, an easily expanding material might cause a lifting of anterior guide pin. In this study, we investigated whether the lifting of anterior guide pin produces some discrepancy in the upper and lower jaw relation on the articulator or not. Furthermore, a plaster model experiment was made to reduce such lifting of guide pin. The results showed that lifting of the anterior guide pin was produced by setting expansion and hygroscopic setting expansion of dental plaster used for mounting (MT plaster). The plaster model experiment to examine the upper and lower relation on the articulator showed that there was some significant discrepancy in the upper and lower relation on the articulator, of which mechanism was markedly different from that in the original maxillomandibular relation. Here, we described that the work of mounting so as to inhibit the expansion of mounting plaster was a key step to recreate the original maxillomandibular relation of oral cavity and the reason why the step was thought most important for dental technicians.
