SECTIONAL IMPRESSIONS FOR MANDIBULAR DISTAL-EXTENSION REMOVABLE PARTIAL DENTURES

Statement of problem. Corrected impression procedures provide the best possible support to be gained from an edentulous ridge for a removabl e partial denture, but they are time-consuming and technique-sensitive . Purpose. An experimental mandibular distal extension removable parti al denture was used to measure the vertical movement of denture bases during biting. Material and methods. Five patients participated for wh om vertical movement of denture bases was measured by comparing the th ickness of plaster interocclusal records made with the denture at rest and under biting pressure. Denture bases were processed on master cas ts formed from final impressions made in full arch custom trays. Secon dly, bases were readapted using sectional relining impressions with th e same regular body polysulfide impression material. Results. Statisti cal analysis of the vertical movement of denture bases during biting a t 4 paints on the right and left denture bases showed a significant de crease in vertical movement with sectional impression. The reduction w as less than a 0.1 mm, a result that questions the routine use of sect ional impression for every distal-extension mandibular removable parti al denture. Conclusion. Supportive form of distal-extension edentulous ridges can be recorded successfully by full arch impressions in custo m trays.