\begin{summary}

Acquiring practical skills in periodontal treatment procedures within dental education traditionally requires extended training periods, numerous clinical applications, and exposure to real patients. In this study, an interactive virtual reality simulation system named \textit{DentClear} was developed for teaching the dental calculus cleaning (scaling/detertraj) procedure.

The system was initially designed based on a Mixed Reality (MR) architecture, integrating a real phantom jaw model and a physical dental scaler instrument into a virtual environment via HTC Vive trackers. However, through iterative testing, critical technical deficiencies were systematically documented: tracking interference between proximal trackers, signal occlusion, positional drift ($\pm$8~mm), rotational instability, and ergonomic incompatibility caused by tracker mass added to the scaler instrument. Based on these findings, the MR-based architecture was determined to be unsustainable, and the system was strategically pivoted to a fully VR-native architecture.

In the final system, the user physically holds only two 6DoF SteamVR trackers, while complete jaw anatomy and the dental scaler are simulated within Unity Engine. Tracker position and rotation data are transmitted in real time to the Unity transform system via OpenXR and the SteamVR Plugin. The system incorporates novel engineering modules including: collision-based interaction, a scaler angle analysis algorithm, dynamic material blending for visual surface state transitions, and a dual-tip scaler interaction mechanism.

The developed in-VR feedback panel presents procedural training metrics in real time, including instantaneous scaler angle, cleaning completion percentage, optimal angle ratio, and a composite performance score. User evaluations ($n=20$) demonstrated 74.3\% average cleaning success, a SUS usability score of 76.2, and 90\% of participants endorsing integration of the system into dental curricula, confirming the educational efficacy of the simulation.

\end{summary}
