Comparison of the marginal fit of digital and conventional crowns with different prosthetic materials

Abstract

The marginal adaptation of dental crowns is a key factor in the clinical success of prosthetic restorations, as it influences the prevention of secondary caries, periodontal inflammation, and loss of retention. This study aimed to compare the marginal adaptation of crowns fabricated using conventional and digital techniques with various prosthetic materials. It was a relational-comparative level investigation with a quantitative and cross-sectional design, conducted under controlled laboratory conditions at the Dentolux clinic in Ibarra (Ecuador) between May and September 2023. A non-probabilistic convenience sample of five standardized dental models was used, in which crowns were fabricated from five different materials (metal-ceramic, lithium disilicate, zirconia, wax, and resin) using both conventional and digital techniques, resulting in a total of 50 crowns distributed across ten experimental groups. Marginal adaptation was measured in microns using a calibrated micrometric spacer and stereomicroscopic observation at 57× magnification. Data were analyzed using SPSS v.26 software, applying the Chi-square test with a significance level of 0.05. The results showed that crowns fabricated using the digital technique exhibited better marginal adaptation than those produced by the conventional method, especially with materials such as zirconia and lithium disilicate. Although the differences were not statistically significant, a consistent trend favoring the digital workflow was observed. It is concluded that the manufacturing method significantly influences marginal precision and that the digital workflow offers greater clinical predictability.