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Comparing Digital Reduction Guides and Free-Hand Techniques for Predoctoral Crown Preparation Accuracy
Xiaoyue Shi1, Shuncong Xu2, Chenxuan Wei1
1Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, Michigan, USA.
Journal of Dental Education
|February 11, 2026
Summary
Digitally designed, 3D-printed guides significantly improved dental students' accuracy and efficiency in crown preparation compared to freehand methods. This technology enhances preclinical training and standardizes outcomes for better dental practice.
Area of Science:
- Dental Education
- Digital Dentistry
- Prosthodontics
Background:
- Insufficient tooth reduction negatively impacts dental crown longevity and aesthetics.
- Accurate crown preparation is crucial for successful restorative outcomes.
- Digital workflows are increasingly integrated into dental education.
Purpose of the Study:
- To evaluate if digitally designed, 3D-printed reduction guides enhance crown preparation accuracy and efficiency for dental students.
- To compare student performance using guided preparation versus traditional freehand techniques.
Main Methods:
- A randomized crossover study involved 25 dental students preparing typodont teeth.
- Students used both freehand and segmented 3D-printed guides for preparation.
- Preparation quality was assessed using a rubric and digital analysis; usability was evaluated via NASA-TLX surveys.
Main Results:
- The guided preparation method significantly improved accuracy scores (p < 0.05) and reduced preparation time by 17% (p < 0.05).
- 64% of students achieved higher accuracy scores with the guide.
- Despite some perceived difficulty, the overall workload was rated as manageable, indicating good guide usability.
Conclusions:
- Custom 3D-printed reduction guides substantially enhance accuracy and efficiency in anterior crown preparation for dental students.
- Integrating these digital guides into preclinical curricula can standardize training and improve the transition to clinical practice.
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