Bur wear ceramics

BACKGROUND: This study aimed to assess the effect of polishing versus glazing of computer-aided design-computer-aided manufacturing (CAD-CAM) ceramics on depth of wear and surface roughness of opposing composite resin. MATERIALS AND METHODS: This in vitro study was conducted on 40 Z250 composite and 40 CAD-CAM ceramic specimens including Celtra Duo, Vita Mark II, e.max CAD, and Vita Suprinity ceramics. All ceramic specimens were roughened by a fine-grit bur after primary glazing to simulate an adjusted surface in the clinical setting...

INTRODUCTION: Adjustments with diamond burs on the ceramic surface can affect its roughness and decrease flexural strength. This study evaluated the effect of polishing or glazing on the surface roughness and biaxial flexural strength of a zirconia-reinforced lithium silicate glass-ceramic upon adjustment with diamond burs. METHODS: Seventy disks were prepared according to ISO 6872 and divided into seven groups (n = 10) according to different adjustments and finishing processes...

BACKGROUND: During the debonding phase every clinician has to take care of preserving the enamel structure and tooth temperature. The objective of this study is to analyze in vitro the increase of the pulp chamber temperature and the wearing of enamel surface, during adhesive removal after debonding. METHODS: 60 extracted human teeth were selected. An orthodontic bracket was bonded on each tooth and after bracket removal, intraoral scanner pictures were used to evaluate ARI for each tooth...

PURPOSE: Various surface roughness parameters are utilized to describe the surface in the tooth to ceramics abrasion and to assess the resulting wear. The use of three-dimensional parameters may offer a better estimation for wear and an improved deduced clinical surface treatment. The aim of this study was to determine the influence of various surface roughness parameters of zirconia and lithium disilicate ceramics on the wear of steatite antagonists. MATERIAL AND METHODS: Forty zirconia specimens with a diameter of 7 mm and a thickness of 3 mm and 40 lithium disilicate specimens with the dimensions 10×10×4 mm were each divided into five subgroups...

OBJECTIVES: This study evaluated the surface integrity of two types of diamond burs and their effect on the roughness of different CAD/CAM materials. MATERIALS AND METHODS: CAD/CAM materials, Vita Mark II (VM), IPS e.max CAD (EM), Celtra Duo (CD), G-Ceram (GC), and Lava Ultimate (LU) blocks were milled with CEREC MCXL. Five pairs of pointed cylinder burs (CB) and step burs (SB) were used repeatedly. The wear rate of burs was analyzed before and after milling with a scanning electron microscope (SEM) and weighing the burs...

Background: Dental ceramics are known for their natural appearance and their durable chemical and optical properties, and their uses mainly reflect their excellent aesthetic properties, biocompatibility and resistance to wear. In addition, dental ceramics are considered to be chemically inert restorative material with large differences in the chemical compositions and microstructures. Although ceramics exhibit excellent physical properties and biocompatibility, the oral environment presents a series of external factors that affect its physical and mechanical properties in its long term function...

OBJECTIVES: This laboratory study aimed to assess the effect of successive crown millings on the marginal misfit of monolithic full-ceramic restorations obtained from two lithium disilicate systems, with a single diamond bur set used for each material in a chairside computer-aided design/computer-aided manufacturing (CAD/CAM) unit. METHODS AND MATERIALS: Initially, 36 standardized composite resin dies were produced by additive manufacturing from a three-dimensional model of a right mandibular first molar with full-crown preparation generated in CAD software...

OBJECTIVES:  The aim of this study was to evaluate the bonding strength of self-adhesive luting cement to zirconia under different surface treatments. MATERIALS AND METHODS:  Thirty-two zirconia samples were randomly divided into eight experimental groups based on the surface treatment employed (Control: no surface treatment; PMM: wear with diamond bur; JAT: blasting with glass beads; PMA: wear with a medium-roughness milling machine; Primer: primer application on the surface without treatment; PMM +Primer: PMM treatment plus primer application; JAT+Primer: JAT treatment plus primer application; and PMA+Primer: PMA treatment plus primer application)...

OBJECTIVES: The aims of this study were to test the hypotheses that (1) a laser scanner used for measuring maximum depth and volume loss will yield the same results as a surface profilometer; (2) the surface roughness will affect the maximum depth and volume loss measured with the laserscanner; (3) analytical results using the laserscanner from multiple operators have no more than 10% inter-rater difference; (4) replicating samples using either stone or impression material is an accurate method for measuring wear using the laserscanner...

The aim was to investigate the effect of machining instruments on machinability of dental ceramics. Four dental ceramics, including two zirconia ceramics were machined by three types (SiC, diamond vitrified, and diamond sintered) of wheels with a hand-piece engine and two types (diamond and carbide) of burs with a high-speed air turbine. The machining conditions used were abrading speeds of 10,000 and 15,000 r.p.m. with abrading force of 100 gf for the hand-piece engine, and a pressure of 200 kPa and a cutting force of 80 gf for the air-turbine hand-piece...

STATEMENT OF THE PROBLEM: Porcelain laminate veneer is an esthetic restoration used as an alternative to full veneer crowns and requires minimal tooth preparation. In restoration with porcelain laminate veneers, both the longevity of the laminate and conservation of the sound tooth structure are imperative. PURPOSE: The present study aimed to investigate the shear bond strength of porcelain laminates to prepared- and unprepared- anterior teeth in order to compare their longevity and success rate...

PURPOSE: Polishing procedures might alter monolithic zirconia (MZ) surface resulting in phase changes that can be deleterious for clinical performance and antagonist tooth wear. This study investigated the topographical features and phase transformation in MZ after polishing with different regimens simulating the clinical workflow. ​ MATERIALS AND METHODS: MZ specimens (Katana Zirconia HT, Kuraray-Noritake) (12×12×1.8 mm(3)) were grinded and polished using one of the five systems assessed: BG: Silicone carbide polishers (Brownie, Greenie, Super Greenie); CG: Diamond impregnated ceramic polisher kit (Ceragloss); EV: Synthetically bonded grinder interspersed with diamond (EVE Kit); SL: Urethane coated paper with aluminium oxide grits (Soflex Finishing and Polishing System Kit) and DB: Diamond bur (8 µm)...

Esthetic high-strength lithium disilicate glass ceramics (LDGC) are used for monolithic crowns and bridges produced in dental CAD/CAM and oral adjusting processes, which machinability affects the restorative quality. A machinability study has been made in the simulated oral clinical machining of LDGC with a dental handpiece and diamond burs, regarding the diamond tool wear and chip control, machining forces and energy, surface finish and integrity. Machining forces, speeds and energy in in vitro dental adjusting of LDGC were measured by a high-speed data acquisition and force sensor system...

The aim of this study was to evaluate the efficacy of different surface conditioning methods on the microtensile bond strength of a restorative composite repair in three types of dental ceramics: lithium disilicate-reinforced, leucite-reinforced and feldspathic. Twelve blocks were sintered for each type of ceramic (n=3) and stored for 3 months in distilled water at 37 °C. The bonding surface of ceramics was abraded with 600-grit SiC paper. Surface treatments for each ceramic were: GC (control) - none; GDB - diamond bur #30 µm; GHF - hydrofluoric acid (10%); GT- tribochemical silica coating (45-μm size particles)...

OBJECTIVE: Recently there has been talk of the use of full-contour solid zirconia crowns or bridge restorations with no porcelain overlay. This could be a useful solution for patients with bruxism or limited interocclusal space. However, the hardness of zirconia could affect the opposite natural dentition. The aim of this in-vitro study was to investigate the role of surface treatments on the wear of a zirconia material and its antagonist. MATERIALS AND METHODS: Fifty plates (10 × 10 × 1 mm) made of zirconia (LavaMulti(™) ZrO2, 3M ESPE), divided into five equal groups, were sandblasted and ground under standardized conditions with a fine-grit diamond bur (Komet Brasseler, Germany) to simulate clinical conditions...

OBJECTIVE: To investigate the effects of polishing techniques on the surface roughness of Y-TZP ceramic and on the wear behavior of synthetic hydroxyapatite (HA). METHODS: Thirty-two full-contour Y-TZP (Diazir(®)) sliders (φ=2 mm × 1.5 mm in height) were manufactured using CAD/CAM, embedded in acrylic resin using brass holders, and randomly allocated into four groups (n=8): according to the finishing/polishing procedure: G1-as-machined, G2-glazed, G3-diamond bur finishing and G4-G3+OptraFine(®) polishing kit...

PURPOSE: The aim of this study was to establish the wear and cutting efficiency of tungsten carbide burs from different manufacturers by performing cutting tests with machinable glass ceramic. MATERIALS AND METHODS: Cutting tests were performed with 70 tungsten carbide burs from seven manufacturers: (A) Coltene/Whaledent, (B) CEI, (C) Meisinger, (D) Axis, (E) Komet, (F) Kerr, (G) Edenta. All groups were examined under scanning electron microscope (SEM) before and after the cutting efficiency test for similarities and differences...

OBJECTIVE: To correlate different laboratory wear simulation protocols for three denture tooth materials with clinical wear results of the same materials. METHODS: Three denture tooth materials were evaluated for which clinical wear data of posterior denture teeth were available: DCL (double cross-linked PMMA with organic fillers; Ivoclar Vivadent), experimental material EM (double cross-linked PMMA with organic fillers; Ivoclar Vivadent), and NFC (PMMA with inorganic nanofillers, Candulor)...

The favourable mechanical properties and high biocompatibility of the newly developed mixed ceramics composed of zirconium oxide and aluminium oxide have continuously extended the scope of their application. Rotating instruments on a zirconium oxide basis are regarded as superior to metal burs in dentoalveolar surgery in terms of favourable temperature effects on the surrounding bone tissue and the economic advantage that they wear slowly, enabling them to be used repeatedly. In this study ten round burs made of zirconium oxide and aluminium oxide mixed ceramics were used for typical dental-alveolar preparation types on an explanted pig jaw...

STATEMENT OF PROBLEM: Amid increasing use of preparable ceramic implant abutments, there is a lack of quantitative data to show which abrasive particle size of diamond bur yields the fastest reduction and provides the smoothest surface. PURPOSE: The research aim was to determine the effects of diamond bur abrasive particle size and abutment material composition on preparation efficiency, prepared surface roughness, and surface deterioration of diamond burs. MATERIAL AND METHODS: Fifteen alumina (Cera Base) and 15 zirconia (ZiReal) implant abutments were each machined using a high-speed hand piece with a diamond bur having 1 of 3 abrasive particle sizes (150, 100, or 30 microm) (n=5)...