Rule-based planning for automated endodontic treatment: From dental radiography, three-dimensional computer modeling to tool selection and path control

More than 24 million teeth receive endodontic (root canal) treatment annually. Traditional techniques are to a great extent relying on the skill (e.g. tactile sense and accumulated experience) and judgment of the clinician, and root canal treatment is often time consuming and prone to human error. The objective of this study is to apply advanced engineering and computer aided technology to modernize the traditional way to science-based automation to improve the quality of care during endodontic treatment.; Before a clinician's inspection of the inner dental anatomy, a destructive access preparation by removing teeth crown is usually needed. In this study, a less invasive technique and a computer program are developed to assess internal tooth geometry by building 3-D tooth models from 2-D radiographs, in a clinically feasible way. This model reveals the dimensions and geometry of the root canal, and displays the location of canal orifice and canal curvature in 3-D computer graphics. Three cases have been investigated to verify and test the usability of the 3-D modeling computer program. The experiments have been designed and conducted to obtain measured root canal results by slicing method, in order to evaluate the accuracy of root canal geometry described by the 3-D model. The measured results and modeled data have been compared accordingly.; According to both dental and engineering requirements, a rule-base has been set. The tool and process database has also been established for the automated root canal treatment. Based on the rules, and with the information provided by 3-D root canal model and by tool and process database, a computer-aided process planning system for endodontic treatment has been developed. The system chooses and positions the treatment tools, controls the tool paths and motions, and outputs the standard numerical controlled program. This computer program is also applied to three different kinds of teeth in this study. From the testing, it is concluded that computer-aided rule-based process planning is feasible and will be useful in the future endodontic therapy.