Chemical vapour deposition of diamond coatings onto molybdenum dental tools

Abstract

The growth of polycrystalline diamond films onto molybdenum rods and dentalburrs by using a new hot filament chemical vapour deposition (CVD) system hasbeen investigated. Negative dc bias voltage relative to the filament was appliedto the molybdenum substrate prior to deposition. This led to much improvedfilm adhesion and increased nucleation density. There was a factor of fourimprovement in the adhesive force from 20 to 80 N when a bias voltage of−300 Vwas employed to the substrate.The CVD coated molybdenum dental burr was found to give much improvedperformance and lifetime compared to the conventional sintered diamond burr. TheCVD diamond burr showed no signs of deterioration even after 1000 operationswhereas the conventional sintered diamond burrs were ineffective after between 30and 60 operations. This represents a 30-fold improvement when CVD is applied.CVD diamond growth onto dental burrs has the potential for replacing excitingtechnology by achieving better performance and lifetime in a cost-effective manner.