Removable partial denture (RPD) planning traditionally involves the conventional assessment of the definitive cast using a dental surveyor. With technological advancements, digital workflows for RPDs have become more prevalent and are enhanced by digital planning software programs that allow digital surveying. However, comparisons of conventional and digital survey techniques are lacking.

The purpose of this cross-sectional study was to compare the retentive areas on the buccal surfaces of abutment teeth obtained through digital and conventional survey methods.

Thirty-five abutment teeth were selected from 10 diagnostic casts for partially dentate individuals, encompassing all Kennedy classifications of both arches. A single examiner surveyed each diagnostic cast using digital and conventional techniques. The conventional surveys were performed with a mechanical surveyor using the Applegate method.

For the digital survey, the stone casts were scanned using a laboratory scanner, and the exocad DentalCAD planning software program was used. The retentive areas located apical to the survey lines obtained with both methods were calculated using the Rhinoceros 3D engineering software program and were superimposed for comparison. Data normality was verified using the Shapiro–Wilk test, and the results were analyzed using the paired Student t test. The effects of the Kennedy classification of the partially edentulous dental arch casts, the tooth type, and the tooth position were tested for overlap of the methods using ANOVA (α=.05).

The retentive areas on abutment teeth obtained with the conventional method were greater than those obtained digitally (P<.001). All digitally defined retention areas were contained within the greater conventionally defined areas.

Conventional and digital surveying methods provide different retentive areas. As areas acquired by the digital survey were smaller and restrained by those of the conventional method, the digital technique should be more able to accurately locate the RPD’s retentive clasp terminus. Further studies are needed to verify such an assumption.