All ETDs from UAB

Advisory Committee Chair

John O Burgess

Advisory Committee Members

Michael McCracken

Amjad Javed

Mark Litaker

Document Type

Thesis

Date of Award

2011

Degree Name by School

Master of Science (MS) School of Dentistry

Abstract

CAD/CAM units are becoming increasingly popular for milling all ceramic restorations from ceramic blocks. The solution used to spray the diamond cutting instrument also improves cutting effectiveness and also lubricates the diamond, which may not only prolong the cutting life of the diamond instrument but also provide smoother cuts on the ceramic block. The purpose of this study is to evaluate cutting efficacy of diamond burs with three solutions and to compare roughness produced by each solution on the glass-ceramic block. Material and methods: 15 Empress CAD blocks, 30 fine diamond burs, two solutions and distilled water were used. Each bur was made four, 4 mm deep cuts in the ceramic blocks for five minutes per cut. The burs were placed in an E4D milling head operating at 40,000 rpm. The blocks were mounted in a testing apparatus that pulled a moveable table at a load of 200g against the diamond bur. The blocks and burs were weighed before and after each cut and after acetone ultrasonic cleaning between cuts (OHAUS digital scale, OHAUS Corporation, NJ, USA). The length of each cut was measured by Keyence 3D digital microscope (Keyence VHX 6000 Series, KEYENCE America, USA). The surface roughness of cuts and burs were measured with a 3D noncontact profilometer (Proscan 2000, Scantron Industrial Products Ltd, England). All statistical analyses were performed using one- and three-way ANOVA. All statistical tests were performed at the 1% significance level and p-values less than or equal to 0.001. LinesTM Micrylium produced significantly longer cut length followed by KNK (p<0.001).LinesTM Micrylium produced significantly higher weight loss followed by KNK (p<0.001). According to a significance level of (α = 0.001), surface roughness and solution interaction is not significant (p > 0.001) for post manufacturing and post cut 4. LinesTM Micrylium and KNK produced less roughness on the edge of blocks, but they were not significantly different from the one using distilled water. (p>0.001)

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