Journal article
Damage tolerance of indirect restorative materials (including PICN) after simulated bur adjustments.
- Coldea A Research and Development Department, VITA Zahnfabrik, Ballyweg 6, 79713 Bad Saeckingen, Germany; Department of Oral Rehabilitation, School of Dentistry, University of Otago, PO Box 647, Dunedin, New Zealand. Electronic address: a.coldea@vita-zahnfabrik.com.
- Fischer J Research and Development Department, VITA Zahnfabrik, Ballyweg 6, 79713 Bad Saeckingen, Germany; Institute for Material Sciences and Engineering, University of Basel, Hebelstrasse 3, 4056 Basel, Switzerland.
- Swain MV Department of Oral Rehabilitation, School of Dentistry, University of Otago, PO Box 647, Dunedin, New Zealand; Biomaterials Unit, Faculty of Dentistry, University of Sydney, Sydney, NSW, Australia.
- Thiel N Research and Development Department, VITA Zahnfabrik, Ballyweg 6, 79713 Bad Saeckingen, Germany.
- 2015-04-11
Published in:
- Dental materials : official publication of the Academy of Dental Materials. - 2015
Adjustments
Damage tolerance
Dental ceramics
Grinding
Interpenetrating phase composite
Mechanical properties
Aluminum Oxide
Ceramics
Computer-Aided Design
Dental Equipment
Dental Materials
Dental Porcelain
Dental Prosthesis Design
Diamond
Elastic Modulus
Hardness
Materials Testing
Surface Properties
English
OBJECTIVE
To analyze the damage tolerance of indirect restorative materials after grinding with diamond burs to simulate adjustments by clinicians and technicians.
METHODS
Seven commercially available restorative materials (Mark II, ENAMIC, In-Ceram Alumina, VM 9, In-Ceram YZ, IPS e.max CAD) and an experimental one (PICN) were analyzed. Forty bending bars per material were fabricated according to manufacturer's instructions and lapped with 15 μm diamond suspension. The initial flexural strength was determined in three-point-bending on 10 specimens. Additionally the elastic modulus and Poisson's ratio were determined by the resonant frequency method. The remaining bending bars were divided into six groups (n=5) and subjected to standardized grinding with three different diamond grit burs (coarse, 151 μm; medium, 107 μm and extra fine 25 μm) and two grinding directions (transversal and longitudinal). The ground specimens were subsequently loaded to fracture and analyzed by SEM.
RESULTS
Except for the YTZP bending bars, the initial materials strength of all tested materials decreased significantly with all diamond burs upon adjustments in both transversal and longitudinal grinding directions. The resistance of the ground materials to strength reduction follow the order from highest to least damage tolerant material: PICN>ENAMIC>Mark II>VM 9>In-Ceram Alumina>IPS e.max CAD. The loss in strength of all examined materials after longitudinal grinding is generally less compared to transversal grinding. The lowest loss in strength occurred for VM 9 (7.79%) and ENAMIC (9.18%) upon longitudinal grinding direction with extra fine and medium diamond grit bur, respectively.
SIGNIFICANCE
The damage tolerance of restorative materials upon adjustments depends on specific mechanical properties and the adjustment procedure. The outcomes of the simulated grinding protocols of this study can be adopted clinically in terms of the selection of appropriate materials, burs and adjustment parameters.
To analyze the damage tolerance of indirect restorative materials after grinding with diamond burs to simulate adjustments by clinicians and technicians.
METHODS
Seven commercially available restorative materials (Mark II, ENAMIC, In-Ceram Alumina, VM 9, In-Ceram YZ, IPS e.max CAD) and an experimental one (PICN) were analyzed. Forty bending bars per material were fabricated according to manufacturer's instructions and lapped with 15 μm diamond suspension. The initial flexural strength was determined in three-point-bending on 10 specimens. Additionally the elastic modulus and Poisson's ratio were determined by the resonant frequency method. The remaining bending bars were divided into six groups (n=5) and subjected to standardized grinding with three different diamond grit burs (coarse, 151 μm; medium, 107 μm and extra fine 25 μm) and two grinding directions (transversal and longitudinal). The ground specimens were subsequently loaded to fracture and analyzed by SEM.
RESULTS
Except for the YTZP bending bars, the initial materials strength of all tested materials decreased significantly with all diamond burs upon adjustments in both transversal and longitudinal grinding directions. The resistance of the ground materials to strength reduction follow the order from highest to least damage tolerant material: PICN>ENAMIC>Mark II>VM 9>In-Ceram Alumina>IPS e.max CAD. The loss in strength of all examined materials after longitudinal grinding is generally less compared to transversal grinding. The lowest loss in strength occurred for VM 9 (7.79%) and ENAMIC (9.18%) upon longitudinal grinding direction with extra fine and medium diamond grit bur, respectively.
SIGNIFICANCE
The damage tolerance of restorative materials upon adjustments depends on specific mechanical properties and the adjustment procedure. The outcomes of the simulated grinding protocols of this study can be adopted clinically in terms of the selection of appropriate materials, burs and adjustment parameters.
- Language
-
- English
- Open access status
- closed
- Identifiers
-
- DOI 10.1016/j.dental.2015.03.007
- PMID 25858782
- Persistent URL
- https://sonar.ch/global/documents/92005
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