Trueness of Intaglio Surface of Milled Digital Dentures Designed from Intraoral Scans

Purpose: To asses trueness of the intaglio surface of milled dentures fabricated according to a fully digital protocol starting from intraoral scans in a clinical study by means of 3-dimensional (3D) digital analysis. Materials and Methods: Ten maxillary and 10 mandibular dentures, designed from intraoral scans and milled in-house, were studied. Intraoral scans were compared with the scans of intaglio surface of milled dentures. To this end, they were aligned, trimmed and used in a metrology software to measure their mean 3D distance, absolute mean deviation, and other parameters. Measured differences for all parameters were statistically investigated. Subgroup analysis for the maxillary and mandibular dentures was performed using independent samples t-test or, in case of non-normal distribution, by means of Mann-Whitney test. Results: Using a mean of 24.9 ±2.8 measurement points/mm2, a mean 3D distance of 0.0006 ±0.007 mm between intraoral scans and the scans of the intaglio surface of milled dentures was measured. The corresponding absolute mean deviation was 0.055 ±0.032 for maxillary dentures and 0.061 ±0.016 for mandibular dentures; such a difference between arches was statistically significant (p = 0.035). Conclusions: Milled dentures fabricated using a fully digital protocol and intraoral scans have accurate intaglio surfaces. It is reasonable to assume that they may achieve an adequate fit.