Evaluation of Occlusal Adjustment Material Removal on Monolithic Zirconia Blocks: An In Vitro Study

This study aims to improve understanding of the amount of tooth-replacement material removed during a single grinding "stroke" performed in the adjustment of a zirconia crown. Zirconia is a highly durable ceramic material commonly used for dental restorations, and accurate adjustment is essential for achieving proper occlusion. However, existing literature does not provide quantitative data regarding material removal per stroke during chairside adjustment, resulting in reliance on individual clinical experience. In this study, standardized zirconia specimens will be prepared and assigned to three operator groups: dental students, dental interns, and experienced clinicians. Each participant will perform a controlled number of grinding strokes on the specimens using a commonly used dental grinding stone. Specimens will be scanned before and after grinding using a three-dimensional scanner to precisely quantify material removal. Hypothesis The hypotheses of this study are: Each grinding stroke results in a measurable and relatively consistent amount of zirconia material removal. Experienced clinicians demonstrate more controlled and predictable material removal per stroke compared with students and interns.

NCT Number	NCT07280130
Lead Sponsor	National Taiwan University Hospital
Conditions	Dental Occlusion, Occlusal Wear of Teeth, Fixed Dental Prosthesis
Enrollment	120 participants
Start Date	2026-02-01
Primary Completion	2027-06-01 (estimated)
Study Completion	2027-12-31 (estimated)
Updated on ClinicalTrials.gov	2025-12-30