This paper treats the improvement of the dental treatment training system proposed by the authors. Dental course students have to pay much money for their dental treatment training because the training needs expensive dentures that are discarded after that. If dental course students can use a training system that provides teeth as 3D CG models virtually, they can reduce their training costs drastically because such 3D CG models can be used repeatedly and there are not any physical losses. Therefore, the authors have already proposed a dental treatment training system using a haptic device called Phantom that works as a dental drill. In this first system, the polygonal mesh subdivision was adopted for making a accurate shaved tooth shape. However, there were several problems so that the authors proposed new system that solved these problems. Indeed, there were still other problems in this previous system. In this paper, the authors also propose new system that solved these previous problems. This paper describes how the authors improved the system and also shows evaluation results by three dental course students to justify the improvement.