Accuracy of freely adapted resin record bases

Forty autopolymerizing resin record bases were made; 10 bases were adapted by finger pressure on tray resin material dough, 10 bases by sprinkling orthodontic resin, and 10 of repair material by either of the two previous techniques. Stone casts and acrylic resin bases were sectioned at canine, premolar, and molar coronal planes. Width of the gap between base and cast and the thickness of the base were measured at the buccal sulcus, ridge crest, lateral palatal slope, and palatal midpoint. Measurements were made through the eyepiece of a microhardness tester. Statistical analysis of 760 pairs of measurements revealed that (1) sprinkled bases fit better than finger-adapted dough bases; (2) specifically formulated materials fit better than repair material with either technique; (3) gap widths differed at different areas of the same base; and (4) gap width was not related to base thickness at any point.