Dimensional changes of processed denture bases after relining with two direct and indirect methods

Relining is a common technique for maintenance and improvement of denture base fit with underlying mucosa. Some dimensional changes might occur in denture base due to relining procedures. The aim of the present study was to evaluate dimensional changes of denture bases after relining with two direct and indirect methods. An acrylic model of maxillary edentulous arch was selected in this in vitro study. Four reference points were placed on canines (A and B) and second molars (C and D). A 1.5-mm wax layer was placed on the model to make room for relining material. An impression was then made of the model. This impression was poured and 20 casts were poured. A 2-mm wax layer was placed on all the casts and the acrylic were stored in water for two weeks. Relining procedures were carried out directly with GC-Reline material and indirectly with Acrosoft TC material in two separate groups. The created lines were exactly measured by digital caliper three times on each base and the original model and their means were computed. Independent t-test was used for statistical analysis (α=0.05). The maximum discrepancy between the two techniques was observed at AC distance. The minimum discrepancy with the direct and indirect techniques was observed in the BD and AB distances, respectively. The differences between the two techniques and the main model were not significant (p value > 0.05) except for the CD distance in the indirect technique (p value = 0.006). Under the limitations of the present study, the dimensional changes in denture base in both direct and indirect reline were acceptable. Selecting one of these methods would depend on patient’s condition, dentist’s preference and some other factors.