Cutting characteristics of dental diamond burs made with CVD technology

Abstract

ABSTRACT:The aim of this study was to determine the cutting ability of chemical vapor deposition (CVD) diamond burs coupled to an ultrasonic dental unit handpiece for minimally invasive cavity preparation. One standard cavity was prepared on the mesial and distal surfaces of 40 extracted human third molars either with cylindrical or with spherical CVD burs. The cutting ability was compared regarding type of substrate (enamel and dentin) and direction of handpiece motion. The morphological characteristics, width and depth of the cavities were analyzed and measured using scanning electron micrographs. Statistical analysis using the Kruskal-Wallis test (p < 0.05) revealed that the width and depth of the cavities were significantly greater when they were prepared on dentin. Wider cavities were prepared when the cylindrical CVD bur was used, and deeper cavities resulted from preparation with the spherical CVD bur. The direction of handpiece motion did not influence the size of the cavities, and the CVD burs produced precise and conservative cutting. DESCRIPTORS: Dental cavity preparation; Ultrasonography; Diamond; Dentistry, Operative. RESUMO:O objetivo deste estudo foi determinar a habilidade de corte das pontas de diamante obtidas pelo processo de deposição química a vapor (CVD) associadas ao aparelho de ultra-som no preparo cavitário minimamente invasivo. Uma cavidade padronizada foi preparada nas faces mesial e distal de 40 terceiros molares, utilizando-se pontas de diamante CVD cilíndrica e esférica. A habilidade de corte foi comparada quanto ao tipo de substrato (esmalte e dentina) e quanto à direção do movimento realizado com a ponta. As características morfológicas, a largura e profundidade das cavidades foram analisadas e medidas em microscopia eletrônica de varredura. A aná-lise estatística pelo teste de Kruskal-Wallis (p < 0,05) revelou que a largura e profundidade das cavidades foram significativamente maiores em dentina. Cavidades mais largas foram obtidas quando se utilizou a ponta de diamante CVD cilíndrica, e mais profundas quando a ponta esférica foi empregada. A direção do movimento da ponta não influenciou o tamanho das cavidades, sendo os cortes produzidos pelas pontas de diamante CVD precisos e conservadores.

Coating and Surface Treatments on Orthodontic Metallic Materials

“…Other drawbacks include the fact that precursors can be toxic, explosive, expensive, corrosive, the by-products can be hazardous, and films need to be deposited at elevated temperatures, which restricts the types of materials that can be coated [59]. CVD has been used in endodontics to coat NiTi files [60,61] and in the coating of burs used in dentistry [62,63]. The use of this technology for coating metallic substrates in orthodontics has not been reported.…”

Evaluation of Surface Roughness of Monolithic Zirconia after Using Different Polishing Kits

“…The bur used for monolithic zirconia adjustment in this study had a surface covered with plasma deposited diamond, which ensures more uniform wear on material surface due to the higher wear resistance of this type of bur compared to conventional burs with diamond inlaid on its surface [17]. Although the group using 3 polishing tips (GPD)…”

The influence of grain size coating and shaft angulation of different diamond tips on dental cutting

“…This does not implicate the need for moving the handpiece by traction during cavity preparation because gentle movements of the tip against the tooth surface provide effective cutting of the dental substrate in any direction. [5] For better cutting efficiency, the CVDentus ® CVD-coated diamond tips should first be positioned perpendicularly to the tooth surface and then gently pressed using oscillatory or pendulum movements of small amplitude until the desired depth of penetration is reached. The custom-made apparatus used in this study to produce standardized cavities followed the manufacturer's specifications with respect to positioning of the tips and the maintenance of a constant movement during cavity preparation.…”

“…These tips are manufactured using the chemical vapor deposition (CVD) of continuous diamond coatings onto molybdenum shafts, using gases such as methane in an excess hydrogen environment. [5] After physicochemical interactions, a pure diamond film is formed on the surface of the shaft without metallic binder between the crystals, thus providing a cutting surface with thousands of microscopic edges. The CVD technology allows the diamond coating to be strongly adhered to the shaft and to withstand the vibratory oscillations from the ultrasonic cavity preparation.…”