[The centric relation. I. Contribution to the study of the reliability of 3 materials for interocclusal registration]

Three materials commonly used for interocclusal registrations are tested under habitual conditions. The wax-type samples are softened in hot water to the optimal temperature, and then cooled off for hardening either in ice water, or room temperature water, or at room temperature air. These materials are stored for one month. Measurements are taken: - prior to any treatment - after hardening - after storage. The results are statistically analyzed. The least distorsion of material is obtained with the softer wax and vice versa. The room temperature air cooling has given best results. Time does not seem to modify measurements made on heat treated materials which may be accurately stored at room temperature.