COMPARISON OF OCCLUSAL CONTACTS IN MAXIMUM INTERCUSPATION FOR 2 IMPRESSION TECHNIQUES

Statement of problem. At the insertion of a fixed prosthesis, occlusal interferences in maximum intercuspation are often present. Purpose. T his study investigated and compared the accuracy of interocclusal rela tionships in maximum intercuspation for mounted casts obtained from a quadrant dual-arch impression technique and conventional full-arch imp ression techniques. Material and methods. Comparisons were made betwee n an intraoral interocclusal record and interocclusal records made on mounted casts. Irreversible hydrocolloid, reversible hydrocolloid, pol ysulfide, polyether, and polyvinyl siloxane were used for the full-arc h impression technique. For the quadrant dual-arch impression techniqu e, rigid polyvinyl siloxane and light-body polyvinyl siloxane injectio n materials were used. Results. Statistical analysis revealed a statis tically significant difference (p = 0.0017) in the median values among treatment groups. All pairwise multiple comparison procedures (Studen t-Newman-Keuls) indicated the average error of the quadrant dual-arch records was significantly different from the average error of each gro up of records produced with the full-arch techniques (p < 0.05). Compa rison of the records of the full-arch impressions did not reveal any s tatistically significant differences. The average error of tile full a rch records was 72 +/- 33 mu m and the quadrant dual-arch average erro r was 5 +/- 5 mu m. Conclusion. The quadrant dual-arch impression tech nique produced mounted casts with significantly more accurate maximal intercuspal relationships than mounted casts from full-arch impression s.