An Evaluation of Dental Operative Simulation Materials

Objective: To evaluate the properties of different materials used in dental operative simulation and compare them with those of natural teeth. Methods: Phantom teeth (model A5A-500, Nissin Dental Products Inc., Japan), laminated plates (Columbia Dentoform Corp., USA), and prototype ceramic blocks (VITA Zahnfabrik, Germany) were compared with extracted permanent teeth. All samples were cut and polished, then tested with a nano-based indentation system (Ultra Micro-Indentation System, UMIS-2000, CSIRO, Australia). Sixty-four second year dental students and fifteen registered dentists evaluated the drilling sensation of the materials. The tool life (machinability) of new cylindrical diamond burs (ISO 806 314 107524 010) (Komet, GEBR. BRASSELER GmbH & Co. KG, Germany) cutting the three sample materials was tested and the burs were observed using a field emission scanning electron microscope (JEOL 6700 FESEM, JEOL, USA). Results: Nissin teeth and Dentoform plates both had a lower elastic modulus (E) and hardness (H) than the natural enamel, by a factor of ten. VITA blocks were softer than enamel but had higher E and H than dentine. Student and dentist evaluations were widely scattered and inconclusive. VITA ceramic allowed the longest tool life, followed by Dentoform plates and Nissin teeth. Conclusion: The sensation of drilling is a reflection of cutting force and power consumption. An ideal material for dental simulation should be able to generate similar drilling resistance to that of natural tooth. The factors to be considered when choosing a material for simulation teaching include the mechanical properties and, more importantly, the machinability of the material.