available at www.jstage.jst.go.jp/browse/islsm
ORIGINAL ARTICLES
The effect of CO2 and Nd:YAP lasers on CAD/CAM Ceramics: SEM, EDS and thermal studies. Ahmed EL GAMAL 1, Carlo FORNAINI 1,4, Jean Paul ROCCA 1,2,3, Omid H MUHAMMAD 1, Etienne MEDIONI 1,2,3, Annamaria CUCINOTTA 4, Nathalie BRULAT-BOUCHARD 2,3
1: Micoralis laboratoy EA 7354, University of Nice Sophia Antipolis, Nice, France 2: Restorative Dentistry and Endodontics Department, Faculty of Dentistry, University of Nice-Sophia Antipolis, Nice, France 3:Pôle Odontologie, CHU Nice Saint Roch, Nice, France 4: Group of Applied ElectroMagnetics, Information Engineering Department, University of Parma, Italy
Background and aims: The objective of this study was to investigate the interaction of infrared laser light on Computer Aided Design and Computer Aided Manufacturing (CAD/CAM) ceramic surfaces. Material and Methods: Sixty CAD/CAM ceramic discs were prepared and divided into two different groups: lithiumdisilicate ceramic (IPSe.maxCADs) and Zirconia ceramic (IPSe.maxZirCADs). The laser irradiation was performed on graphite and non-graphite surfaces with a Carbon Dioxide laser at 5W and 10W power in continuous mode (CW mode) and with Neodymium Yttrium Aluminum Perovskite (Nd:YAP) laser at 10W. Surface textures and compositions were examined using Scanning Electron Microscopy (SEM), and Energy Dispersive Spectroscopy (EDS). Thermal elevation was measured by thermocouple during laser irradiation. Results: The SEM observation showed a rough surface plus cracks and fissures on CO2 10W samples and melting areas in Nd:YAP samples; moreover, with CO2 5W smooth and shallow surfaces were observed. EDS analysis revealed that laser irradiation does not result in modifications of the chemical composition even if minor changes in the atomic mass percentage of the components were registered. Thermocouple showed several thermal changes during laser irradiation. Conclusion: CO2 and Nd:YAP lasers modify CAD/CAM ceramic surface without chemical composition modifications. Key words: CAD/CAM Ceramics • Laser • SEM • EDS • Thermocouple.
Introduction The demand of ceramic restorations has become increasingly popular in dentistry and the continuous need of precision is still a challenge to be achieved. With the improving the Computer Aided Design and the Computer Aided Manufacturing (CAD/CAM) ceramic technology, one of the most important challenges is to integrate it with the other new technologies. The internal surface of the ceramic restoration Addressee for Correspondence: Ahmed EL GAMAL BDS, MSc Micoralis Laboratory EA 7354 University of Nice-Sophia Antipolis Nice, France E-Mail: [email protected] ©2016 JMLL, Tokyo, Japan
must be prepared with the aim to increase the micromechanical retention of the cement. Surface treatment of CAD/CAM ceramic increases the surface in contact with the tooth structure creating micro-porosities and enhancing the potential for mechanical retention of the cement 1, 2). Different surface treatment methods have been proposed to provide roughness and promote micromechanical retention 3, 4). The identification of non-destructive methods to treat inert ceramics and modify their mechanical and chemical properties may result a good help to produce an activated surface. Received date: December 8th, 2015 Accepted date: February 9th, 2016
Laser Therapy 25.1: 27-34
27
ORIGINAL ARTICLES Surface treatment (laser irradiation) has been involved in the industrial field using high power lasers and represents a controllable and flexible technique aiming to modify the surface properties of different materials 5, 6). Laser processing parameters during such surface modifications are expected to influence the surface microstructure 7) and the hypothesis developed was that Carbon dioxide (CO 2 , 10,600nm) and Neodymium Yttrium Aluminum Perovskite (Nd: YAP, 1340nm) lasers could modify the CAD/CAM surface ceramic specimens (E.maxCAD, Emax ZirCAD). These modifications could be linked to laser-target tissue interaction and also thermal elevation.
Aim of the study The aim of this study was to characterize ceramic specimens (Emax CAD, Emax ZirCAD) irradiated with a CO2 (10,600nm) or Nd:YAP lasers (1340nm). The characterization of the surfaces before and after laser irradiation by using Scanning Electron Microscopy associated with Energy Dispersive Spectroscopy (EDS) allowed to observe the morphological changes and chemical modifications. Moreover, the effect of thermal treatment during laser irradiation was evaluated for both ceramics (Emax CAD, Emax ZirCAD) by using thermocouple device.
Materials and Methods A) Tested ceramics 1) Lithiumdisilicate (EmaxCAD) This material is composed of a lithium silicate with micron-size lithiumdisilicate crystals in between, which are submicron lithium orthophosphate crystals creating a highly filled glass matrix. Lithiumdisilicate is modified by increasing the crystal content to approximately 70% and by refining the crystal size, thus improving the flexural strength to approximately 360 MPa 8-12).
available at www.jstage.jst.go.jp/browse/islsm
Corp., Korea, 10,600nm wavelength) was used with two different output power values (5W and 10W) corresponding to two different power densities (1592.3 W/cm2, 3184.7 W/cm2). Irradiation was conducted in non-contact and continuous mode (working distance 2 mm, spot size of the aiming beam 0.1mm). 2) Nd:YAP laser Nd:YAP laser (Nd:YAP Lokki, Lobel Medical, France, wavelength 1340nm), previously proposed for surface modification with the aim to form a glazed surface layer on the ceramics 14), was used. A 320 µm diameter fibber and output power of 10W corresponding to a power density of 14185 W/cm² were used. Due to the high absorption level of this wavelength in black chromophores, the ceramic surfaces
Table 1: Composition and physical properties of tested ceramics Lithium Disilicate Composition SiO2 57.0–80.0 (wt %) Li2O 11.0–19.0 ZrO2 0.0–8.0 MgO 0.0–5.0 K2O 0.0–13.0 P2O5 0.0–11.0 ZnO 0.0–8.0 Al2O3 0.0–5.0 Coloring oxides 0.0–8.0
ZrO2 87.0–95.0
Physical properties
Flexural strength (biaxial) 360 ± 60 Mpa
Flexural strength (biaxial) 900 x 50 Mpa
Chemical solubility 40 ± 10 µg/cm2
Chemical solubility
ORIGINAL ARTICLES
The effect of CO2 and Nd:YAP lasers on CAD/CAM Ceramics: SEM, EDS and thermal studies. Ahmed EL GAMAL 1, Carlo FORNAINI 1,4, Jean Paul ROCCA 1,2,3, Omid H MUHAMMAD 1, Etienne MEDIONI 1,2,3, Annamaria CUCINOTTA 4, Nathalie BRULAT-BOUCHARD 2,3
1: Micoralis laboratoy EA 7354, University of Nice Sophia Antipolis, Nice, France 2: Restorative Dentistry and Endodontics Department, Faculty of Dentistry, University of Nice-Sophia Antipolis, Nice, France 3:Pôle Odontologie, CHU Nice Saint Roch, Nice, France 4: Group of Applied ElectroMagnetics, Information Engineering Department, University of Parma, Italy
Background and aims: The objective of this study was to investigate the interaction of infrared laser light on Computer Aided Design and Computer Aided Manufacturing (CAD/CAM) ceramic surfaces. Material and Methods: Sixty CAD/CAM ceramic discs were prepared and divided into two different groups: lithiumdisilicate ceramic (IPSe.maxCADs) and Zirconia ceramic (IPSe.maxZirCADs). The laser irradiation was performed on graphite and non-graphite surfaces with a Carbon Dioxide laser at 5W and 10W power in continuous mode (CW mode) and with Neodymium Yttrium Aluminum Perovskite (Nd:YAP) laser at 10W. Surface textures and compositions were examined using Scanning Electron Microscopy (SEM), and Energy Dispersive Spectroscopy (EDS). Thermal elevation was measured by thermocouple during laser irradiation. Results: The SEM observation showed a rough surface plus cracks and fissures on CO2 10W samples and melting areas in Nd:YAP samples; moreover, with CO2 5W smooth and shallow surfaces were observed. EDS analysis revealed that laser irradiation does not result in modifications of the chemical composition even if minor changes in the atomic mass percentage of the components were registered. Thermocouple showed several thermal changes during laser irradiation. Conclusion: CO2 and Nd:YAP lasers modify CAD/CAM ceramic surface without chemical composition modifications. Key words: CAD/CAM Ceramics • Laser • SEM • EDS • Thermocouple.
Introduction The demand of ceramic restorations has become increasingly popular in dentistry and the continuous need of precision is still a challenge to be achieved. With the improving the Computer Aided Design and the Computer Aided Manufacturing (CAD/CAM) ceramic technology, one of the most important challenges is to integrate it with the other new technologies. The internal surface of the ceramic restoration Addressee for Correspondence: Ahmed EL GAMAL BDS, MSc Micoralis Laboratory EA 7354 University of Nice-Sophia Antipolis Nice, France E-Mail: [email protected] ©2016 JMLL, Tokyo, Japan
must be prepared with the aim to increase the micromechanical retention of the cement. Surface treatment of CAD/CAM ceramic increases the surface in contact with the tooth structure creating micro-porosities and enhancing the potential for mechanical retention of the cement 1, 2). Different surface treatment methods have been proposed to provide roughness and promote micromechanical retention 3, 4). The identification of non-destructive methods to treat inert ceramics and modify their mechanical and chemical properties may result a good help to produce an activated surface. Received date: December 8th, 2015 Accepted date: February 9th, 2016
Laser Therapy 25.1: 27-34
27
ORIGINAL ARTICLES Surface treatment (laser irradiation) has been involved in the industrial field using high power lasers and represents a controllable and flexible technique aiming to modify the surface properties of different materials 5, 6). Laser processing parameters during such surface modifications are expected to influence the surface microstructure 7) and the hypothesis developed was that Carbon dioxide (CO 2 , 10,600nm) and Neodymium Yttrium Aluminum Perovskite (Nd: YAP, 1340nm) lasers could modify the CAD/CAM surface ceramic specimens (E.maxCAD, Emax ZirCAD). These modifications could be linked to laser-target tissue interaction and also thermal elevation.
Aim of the study The aim of this study was to characterize ceramic specimens (Emax CAD, Emax ZirCAD) irradiated with a CO2 (10,600nm) or Nd:YAP lasers (1340nm). The characterization of the surfaces before and after laser irradiation by using Scanning Electron Microscopy associated with Energy Dispersive Spectroscopy (EDS) allowed to observe the morphological changes and chemical modifications. Moreover, the effect of thermal treatment during laser irradiation was evaluated for both ceramics (Emax CAD, Emax ZirCAD) by using thermocouple device.
Materials and Methods A) Tested ceramics 1) Lithiumdisilicate (EmaxCAD) This material is composed of a lithium silicate with micron-size lithiumdisilicate crystals in between, which are submicron lithium orthophosphate crystals creating a highly filled glass matrix. Lithiumdisilicate is modified by increasing the crystal content to approximately 70% and by refining the crystal size, thus improving the flexural strength to approximately 360 MPa 8-12).
available at www.jstage.jst.go.jp/browse/islsm
Corp., Korea, 10,600nm wavelength) was used with two different output power values (5W and 10W) corresponding to two different power densities (1592.3 W/cm2, 3184.7 W/cm2). Irradiation was conducted in non-contact and continuous mode (working distance 2 mm, spot size of the aiming beam 0.1mm). 2) Nd:YAP laser Nd:YAP laser (Nd:YAP Lokki, Lobel Medical, France, wavelength 1340nm), previously proposed for surface modification with the aim to form a glazed surface layer on the ceramics 14), was used. A 320 µm diameter fibber and output power of 10W corresponding to a power density of 14185 W/cm² were used. Due to the high absorption level of this wavelength in black chromophores, the ceramic surfaces
Table 1: Composition and physical properties of tested ceramics Lithium Disilicate Composition SiO2 57.0–80.0 (wt %) Li2O 11.0–19.0 ZrO2 0.0–8.0 MgO 0.0–5.0 K2O 0.0–13.0 P2O5 0.0–11.0 ZnO 0.0–8.0 Al2O3 0.0–5.0 Coloring oxides 0.0–8.0
ZrO2 87.0–95.0
Physical properties
Flexural strength (biaxial) 360 ± 60 Mpa
Flexural strength (biaxial) 900 x 50 Mpa
Chemical solubility 40 ± 10 µg/cm2
Chemical solubility
