In vitro study on high rotation deep removal of ceramic prostheses in dental surgery

Abstract

In vitro study on high rotation (up to over 300,000 rpm) deep removal (up to 150 microm) of ceramic prostheses, made of a machinable ceramic, Vita Mark II, was performed in dental surgery using a high-speed dental handpiece. Dental clinical removal relevance, including tangential and normal grinding forces, specific grinding energy, and surface roughness, was investigated to establish the relationships among the surgery parameters, chip geometry, and fracture mechanism. The results show that both the tangential and normal grinding forces increased with increases in both depth of cut and maximum undeformed chip thickness, but decreased with an increase in grinding speed. Specific grinding energy decreased with increase in the depth of cut and the maximum undeformed chip thickness, but increased with an increase in grinding speed. Surface roughness and morphology appeared to be independent of the increases in depth of cut, grinding speed, and maximum chip thickness. The limitation for deep removal using the dental handpiece was found that the operation at the depth of cut of 150 microm or beyond resulted in a huge normal force exertion of 3 N with a great variation. The microfracture, the lateral fracture, and the ductile microcutting were found to occur simultaneously in dental surgery to remove the ceramic prostheses.

Property–process relations in simulated clinical abrasive adjusting of dental ceramics

“…In clinical adjusting, the depths of cut are approximately 10-50 mm although deep adjusting at up to 150 mm depth of cut can be conducted (Yin et al, 2007). These depths of cut are in the same range applied in engineering grinding of ceramics with diamond wheels.…”

Radiation grafting of acrylic acid/N‐vinyl pyrrolidone binary mixture onto poly(ethylene terephthalate) fabric and growth of human mesenchymal stem cell

“…To simulate the intraoral resurfacing process, the in vitro dental resurfacing operations were performed on a computer‐assisted experimental apparatus in the straight surface resurfacing mode. A detailed description on the in vitro experimental setup and testing methodology can be found in the previous study 40. Figure 1(a) shows the image of resurfacing a specimen using a dental handpiece (CST61; Shanghai Medical Instruments, China) and a bur (SF‐21, ISO 110523014; Mani, Japan).…”

“…Water was applied from a water spray nozzle in the dental handpiece to the removal area at a constant flow rate of 30 mL/min to clean any adhered chips. For the given operational parameters, the tangential and normal resurfacing forces were measured to be 0.13–1.84 N and 0.40–3.6 N, respectively; the peripheral speeds V s of the bur were measured to be 21.73–23.04 m/s 40…”

Cracking of Porcelain Surfaces Arising from Abrasive Grinding with a Dental Air Turbine

“…Previous researchers have demonstrated that surface and subsurface damage can arise from diamond bur machining of ceramic under simulated dental operatory conditions 1–4 . To date, most of this damage has been characterized in terms of the mode of machining damage, specifically the brittle and ductile modes of material removal 5 …”