Compatibility of digital and analog methods in assessment of gingival zeniths

The compatibility of digital and analog methods assessing the positions of gingival zenith (GZ) points has not been evaluated before. Therefore, the aim of this study was to investigate the accuracy of a digital scanner and a three-dimensional (3D) measuring tool in specifying positions of GZs by comparing it to the conventional method, an analog plaster cast and a caliper.

Both analog and digital impressions were obtained from 32 individuals. Following measurements were conducted in the anterior maxillary region from canine to canine on both the plaster casts and 3D images: (1) The distance from GZ to the corresponding vertical midline in each tooth (GZVM), (2) The distance from GZ of lateral incisor to the corresponding tangent that connects GZs of central incisor and canine (GZLI).

The intraclass correlation coefficients (ICC) of GZVM in each tooth varied between 0.366 and 0.755, demonstrating moderate to good compatibility between the two methods. The ICC of analog and digital GZLI for the right and left lateral incisors was 0.788 and 0.395, respectively.

The digital and analog methods used in this study are compatible in determining the positions of GZs. Therefore, within the limitations of the present study, the choice of method can be based on the available equipment, time, comfort, and personal preference of the researcher.

Both digital and analog methods have the capability of determining the positions of GZs in compatible way.