Computer‐aided design of anterior guidance with a modified patient‐specific motion technique in anterior implant‐supported single crowns: A multicenter crossover trial

PURPOSE: To compare the clinical effects of computer-aided design (CAD) anterior guidance using a modified patient-specific motion (PSM) technique with the digital articulator in implant-supported crowns. MATERIALS AND METHODS: Sixty-three patients with a missing maxillary incisor scheduled for implant-supported crowns were enrolled from three hospitals. Modified PSM facilitating dynamic occlusion recording was utilized during intraoral scanning by attaching landmarks to the buccal surface of canines or first premolars. For each participant, two crowns were fabricated, differing only in the anterior guidance design. Test and control groups utilized modified PSM and a digital articulator to design anterior guidance, respectively. Crowns were delivered in a randomized sequence, while intraoral scanning and occlusal evaluation were performed. Occlusal adjustment indicators were calculated. Paired t-test and Wilcoxon signed-rank test were primarily used for statistical analysis. RESULTS: Compared with the control group, the test group showed significantly lower maximum occlusal adjustment distance (263.4 [269.6] µm vs. 362.2 [252.0] µm, p = 0.001) but similar mean and root mean square (p > 0.050). The test group demonstrated significantly reduced adjustment time, adjustment area, and lateroprotrusive interferences and higher patient (before/after adjustment) and dentist (before adjustment) satisfaction than the control group (p < 0.050). More test group crowns were selected (42 vs. 21, p = 0.008). The groups had similar occlusal clearance and occlusion scores (p > 0.050). CONCLUSIONS: Compared with a digital articulator, CAD anterior guidance using modified PSM for implant-supported single crowns reduces maximum adjustment distance, adjustment time and area, and occlusal interferences, and improves patient/dentist satisfaction.