Free-hand dental procedures are typically repetitive, time-consuming and require high precision and manual dexterity. Robots can play a key role in improving procedural accuracy and safety, enhancing patient comfort, and reducing operator workload. However, robotic solutions for free-hand procedures remain limited or completely lacking. To address this gap, we develop a haptic bilateral teleoperation system (HBTS) for free-hand dental procedures (FH-HBTS). The system includes a mechanical end-effector, compatible with standard clinical tools, and equipped with an endoscopic camera for improved visibility of the intervention site. By ensuring motion and force correspondence between the operator's and the robot's actions, monitored through visual feedback, we enhance the operator's sensory awareness and motor accuracy. Furthermore, to ensure procedural safety, we limit interaction forces by scaling the motion references provided to the admittance controller based solely on measured contact forces. This ensures effective force limitation in all contact states without requiring prior knowledge of the environment. The proposed FH-HBTS is validated both through a technical evaluation and an in-vitro pre-clinical study conducted on a dental model under clinically representative conditions. The results show that the system improves the naturalness, safety, and accuracy of teleoperation, highlighting its potential to enhance free-hand dental procedures.

翻译：徒手牙科手术通常具有重复性、耗时性，并且要求极高的精度和手工灵巧性。机器人可以在提高手术精度与安全性、增强患者舒适度以及减轻操作者工作负荷方面发挥关键作用。然而，针对徒手手术的机器人解决方案仍然有限或完全缺失。为填补这一空白，我们开发了一种用于徒手牙科手术的触觉双边遥操作系统（FH-HBTS）。该系统包含一个机械末端执行器，与标准临床工具兼容，并配备了一个内窥镜摄像头，以提高手术部位的可见性。通过确保操作者动作与机器人动作之间的运动和力对应关系（通过视觉反馈进行监控），我们增强了操作者的感官意识和运动精度。此外，为确保手术安全性，我们通过仅基于测量的接触力对标提供给导纳控制器的运动参考值，从而限制了交互力。这确保了在所有接触状态下都能实现有效的力限制，而无需环境先验知识。所提出的FH-HBTS通过技术评估和在具有临床代表性条件下于牙科模型上进行的体外临床前研究得到了验证。结果表明，该系统提高了遥操作的自然性、安全性和准确性，凸显了其提升徒手牙科手术的潜力。