Linear Dimensional Accuracy in Maxillomandibular Records: A Comparative Study of Scannable and Transparent Materials

BACKGROUND Maxillomandibular relationship records facilitate patient stomatognathic information transfer to dental laboratories, but new bite registration materials (BRMs) lack scientific evidence on linear dimensional accuracy. This in vitro investigation compared linear dimensional accuracy of 6 commercial scannable and transparent BRMs with a typical BRM at 1 h. MATERIAL AND METHODS Seven American Dental Association (ADA)-approved BRMs were categorized into 1 control and 2 experimental groups: control: Occlufast Rock; scannable group: Occlufast CAD, Virtual CADBite, and Flexitime Bite; and transparent group: Maxill Bite, Charmflex Bite, and Defend ClearBite. The study used modified ADA specification no. 19 to standardize bite registration record samples, which were examined using a stereomicroscope to compare with control group and standard die measurements. Median, interquartile range, and median rank scores were used for statistical interpretation. One-way ANOVA (Kruskal-Wallis rank test) and multiple-comparison Dunn test with Bonferroni correction compared between and within group differences at the probability P value ≤0.05. RESULTS The median linear differences varied in scannable, -0.06 (0.24%) to -0.11mm (0.44%), and transparent, -0.06 (0.24%) to -0.07 (0.28%), BRMs, with transparent BRMs showing more linear accuracy than scannable BRMs. A statistically significant difference from control at 1 h was observed for 3 different commercial brands. All transparent BRMs exhibited markedly reduced linear discrepancies, compared with the standard BRM (P<0.05). CONCLUSIONS All BRMs at 1 h showed a reduced linear dimensions, indicating shrinkage. All investigated BRMs demonstrated clinically acceptable linear discrepancies, with transparent BRMs exhibiting less change than scannable BRMs.