Accuracy of Digital Photography and Intraoral Scanning for Tooth Shade Selection in Digital Prosthodontics: A Comparative Clinical Study Using Spectrophotometry as Reference

Background: The integration of digital technologies into prosthodontics has significantly improved clinical workflows, from intraoral data acquisition to restoration design and fabrication. Accurate tooth shade selection remains a critical step in achieving optimal aesthetic outcomes, with spectrophotometry considered the gold standard. However, alternative digital methods such as intraoral scanners and digital photography are increasingly used in clinical practice. Objective: This study aimed to evaluate the accuracy of intraoral scanning and standardized digital photography for tooth shade selection within a digital prosthodontic workflow, using spectrophotometric measurements as reference. Methods: Twenty participants were included in this clinical study. Tooth color was recorded using a spectrophotometer (reference method), an intraoral scanner (Medit i700), and standardized digital photography, which was analyzed with a Digital Color Meter. Color differences (ΔE) were calculated using the CIELAB formula. Statistical analysis included one-sample and independent-samples t-tests, as well as Bland–Altman analysis to assess agreement between methods. Results: Digital photography showed significantly higher ΔE values (19.37 ± 2.45) compared to the clinical acceptability threshold (ΔE = 3.3; p < 0.001), indicating poor accuracy. The intraoral scanner demonstrated lower ΔE values (5.53 ± 0.62; p < 0.001) but still exceeded the acceptable limit. Bland–Altman analysis confirmed poor agreement for digital photography and a reduced, though still suboptimal, agreement for the intraoral scanner relative to spectrophotometry. Nonetheless, the intraoral scanner demonstrated significantly better agreement than digital photography, supporting its preferential use in digital prosthodontic workflows. Conclusions: Within the context of digital prosthodontics, digital photography cannot be considered a reliable method for shade matching. Intraoral scanners provide improved consistency but do not achieve clinically acceptable accuracy compared to spectrophotometry. Spectrophotometry remains the gold standard, while intraoral scanning may serve as a complementary tool in digital workflows. Future studies with larger samples are needed to confirm these findings.