Minimizing Substance Removal at Regularly Calcified Teeth Using Guided Endodontics

Objectives: To evaluate success rate and the extent of tooth substance removal associated with computer-guided preparation of endodontic access cavities.
Methods: Three types of maxillary acrylic typodont teeth with root canals were selected (incisors, premolars, and molars) and distributed to a study and a control group (15 teeth per group). In the study group, the teeth were fixed in acrylic resin, and subsequently digitized with a laboratory scanner. A cone-beam computer tomography (CBCT) scan was acquired. Access cavity preparations were virtually planned, and a template was 3D-printed. In the control group, access cavities were prepared using the conventional technique. Tooth substance removal was assessed by weighing the teeth before and after preparation. Success rates and tooth substance removal was calculated using frequencies and means along with their standard deviations, respectively. Volume loss between the study groups was compared by use of t-test.
Results: The rate of successfully located root canals was 93.3% using the guided endodontics approach, compared to 100% using the conventional technique. In the control group, mean tooth substance removal was 16.1±3.7 mm^3 for incisors, 44.2±8.9 mm for premolars, and 99.3±3.1 mm^3 for molars. In the study group, significantly less tooth substance was removed (p<0.002). Here, substance loss was 10.3±1.1 mm^3 for incisors, 29.3±4.2 mm^3 for premolars, and 51.8±5.3 mm^3 for molars.
Conclusions: The use of guided endodontics allows the preservation of a significant amount of tooth substance. This advantage must be carefully balanced against a higher radiation dose, a higher risk of perforation, higher costs, and a more difficult debridement and visualization of pulp chamber and root canals.