Effectiveness of CAD/CAM technology: A self-assessment tool for preclinical waxing exercise.

INTRODUCTION: This study assessed the utility of CAD/CAM technology as a self-assessment tool for preclinical waxing compared to traditional student self-assessment to evaluate preclinical work. MATERIAL AND METHODS: Thirty-seven students completed the wax-up of the maxillary left central incisor with the goal of recreating original anatomy and completed a traditional self-assessment. The original, unreduced cast and waxings were scanned with an intraoral scanner (E4D, Planmeca). Using CAD/CAM software (Compare, Planmeca), each waxing was superimposed over the original. Tolerance (250 µm) was set to illustrate under- and over-contoured areas, enabling visualisation of the waxing compared to original in three dimensions. Students then completed another self-assessment and an exit survey. RESULTS: Twenty-four per cent of self-assessment responses changed after using Compare Software. 20% changed from satisfactory to unsatisfactory. Four per cent changed from unsatisfactory to satisfactory. Greatest change in response occurred in the Incisal Edge (49%) rubric category. Interproximal Contact Area (3%) demonstrated least change in response. Seventy per cent strongly agreed that Compare Software enabled more effective assessment of Lingual Contour. Eight per cent strongly disagreed that Compare Software enabled more effective assessment of finishing. DISCUSSION: CAD/CAM software can improve student's critical self-assessment. Different rubric categories demonstrated differing rates of response change, indicating more critical of certain aspects of the waxing. Majority strongly agreed that the software enabled more effective self-assessment. CONCLUSION: CAD/CAM technology enhances student's learning in dental wax-up through improving self-assessment. This technology may improve teacher-student communication, reduce one-on-one teaching time and allow higher student-teacher ratio.

In Vivo Tooth-Supported Implant Surgical Guides Fabricated With Desktop Stereolithographic Printers: Fully Guided Surgery Is More Accurate Than Partially Guided Surgery.

PURPOSE: Desktop stereolithographic printers combined with intraoral scanning and implant planning software promise precise and cost-effective guided implant surgery. The purpose of the present study was to determine the overall range of accuracy of tooth-supported guided implant surgery using desktop printed stereolithographic guides. MATERIALS AND METHODS: A cross-sectional study comparing fully and partially guided implant surgery was conducted. Preoperative cone beam computed tomography (CBCT) and intraoral scans were used to plan the implant sites. Surgical guides were then fabricated using a desktop stereolithographic 3-dimensional printer. Postoperative CBCT was used to evaluate the accuracy of placement. Deviations from the planned positions were used as the primary outcome variables. The planning software used, implant systems, and anterior/posterior positions were the secondary outcome variables. The differences between the planned and actual implant positions in the mesial, distal, buccal, and lingual dimensions and buccolingual angulations were determined, and the accuracy was compared statistically using the 1-tail F-test (P = .01), box plots, and 95% confidence intervals for the mean. RESULTS: Sixteen partially edentulous patients requiring placement of 31 implants were included in the present study. The implant deviations from the planned positions for mesial, distal, buccal, and lingual dimensions and buccolingual angulations with the fully guided protocol (n = 20) were 0.17 ± 0.78 mm, 0.44 ± 0.78 mm, 0.23 ± 1.08 mm, -0.22 ± 1.44 mm, and -0.32° ± 2.36°, respectively. The corresponding implant deviations for the partially guided protocol (n = 11) were 0.33 ± 1.38 mm, -0.03 ± 1.59 mm, 0.62 ± 1.15 mm, -0.27 ± 1.61 mm, and 0.59° ± 6.83°. The difference between the variances for fully and partially guided surgery for the distal and angulation dimensions was statistically significant (P = .006 and P < .001, respectively). No statistically significant difference was found between the software programs. Anterior implants had less variation in deviation than posterior implants. CONCLUSIONS: Fully guided implant surgery is more accurate than partially guided implant surgery. Implant positional deviation is influenced by implant location but not implant systems or software. If possible, clinicians should use guided surgery protocols that allow placement of implants through a surgical guide.