René Martínez-celorio | Universidad de Guanajuato (original) (raw)

Papers by René Martínez-celorio

Research paper thumbnail of Effects of endodontic treatment on apparent Young’s modulus of human teeth: in vitro study using speckle interferometry

Journal of Biomedical Optics, 2012

The introduction of new techniques for endodontic procedures requires the analysis of the biomech... more The introduction of new techniques for endodontic procedures requires the analysis of the biomechanical behavior of dental structures. Digital speckle shearing pattern interferometry (DSSPI) is a nondestructive optical measuring technique that allows one to directly quantify deformations in teeth that are subjected to stress. DSSPI technique was applied to measure small deformations caused by flexion in different types of teeth. The test was carried out both before and after endodontic treatment with the ProTaper method in order to evaluate the variation of dental elasticity, taking into the account the type of tooth and the endodontic treatment. The results obtained show that dental elasticity, established by means of the apparent Young's modulus, before and after the endodontic treatment, differs between incisors and premolars. The endodontic process does not affect dental elasticity (p>0.7). Specifically, 57.1% of central incisors and 56.3% of second premolars slightly increase their elasticity after the endodontic process. In turn, 42.9% of central incisors and 43.7% of second premolars slightly decrease elasticity. The endodontic treatment especially affects the "neutral fibre"; therefore, there is little influence on elasticity by flexion. However, after finishing the process, the channel was restored with material, which can slightly increase tooth elasticity in some cases.

Research paper thumbnail of Interferometric method for characterizing the smile of laser diode bars

Optics Communications, 2007

We propose an interferometric method for the characterization of the smile of laser diode bars (L... more We propose an interferometric method for the characterization of the smile of laser diode bars (LDBs). The LDB is placed in a Lloyd's mirror set-up. The beams coming from the LDB and its virtual image produce Young's fringes, which are captured by a charge-coupled-device array, digitised and saved in a computer as an irradiance matrix. The irradiance matrix is processed in the computer and the smile parameter extracted. The theoretical basis of the method is discussed and simulated fringe patterns of practical situations are presented. A device based on the described interferometric method was mounted and the smile of a commercially available LDB was characterised. Ó 2007 Published by Elsevier B.V.

Research paper thumbnail of "IN-VITRO" STUDY OF PIG BONE SAMPLES USING ELECTRICAL IMPEDANCE SPECTROSCOPY (EIS)

In this paper, an "in-vitro" study of bone samples using electrical impedance spectroscopy (EIS) ... more In this paper, an "in-vitro" study of bone samples using electrical impedance spectroscopy (EIS) is presented. The study was conducted using 30 samples prepared following a pathological procedure that eliminated Ca+2 ions from the samples and altered their porosity. The prepared samples were placed in a capacitor cell to measure the electrical impedance response in relation to the frequency through an HP4294A impedance bridge. These measurements were used to obtain Bode and Nyquist diagrams with which the equivalent RC circuit could be calculated for each of the samples using the Z-view software. The results indicate that there exist significant differences in the values of the electrical impedance module depending on the porosity levels and the loss of minerals in the samples studied. Additionally, the resulting equivalent electrical circuit made it possible to determine the average central frequency values to study the maximal sensitivity of porosity and mineral loss phenomena in our samples. These values were 1.81 MHz and 560 Hz, respectively. The significance of this study lies in the possibilities it presents to use the proposed technique to build non-invasive equipment to detect diseases such as osteoporosis. Advantages and disadvantages of the method used are discussed.

Research paper thumbnail of IN-VITRO STUDY OF BONE SAMPLES USING ELECTRICAL IMPEDANCE SPECTROSCOPY

In this paper an "in-vitro" study of bone samples using the electrical impedance spectroscopy (EI... more In this paper an "in-vitro" study of bone samples using the electrical impedance spectroscopy (EIS) is presented. The study was conducted using 30 samples prepared following a pathological procedure that eliminated Ca +2 ions from the samples and altered their porosity. The prepared samples were placed in a capacitor cell to measure the electrical impedance response in relation the frequency through an HP4294A impedance bridge. These measurements were used to obtain Bode and Nyquist diagrams with which the equivalent RC circuit could be calculated for each of the samples using the Z-view software. The results indicate that there exist significant differences in the values of the electrical impedance module depending on the porosity levels and the loss of minerals in the samples studied. Additionally, the resulting equivalent electrical circuit made it possible to determine the average central frequency values to study the maximal sensitivity of porosity and mineral loss phenomena in our samples, which were 1.81 MHz and 560 Hz, respectively. The significance of this study lies in the possibilities it presents to use the proposed technique to build non-invasive equipment to detect diseases such as osteoporosis. Advantages and disadvantages of the method used are discussed.

Research paper thumbnail of Effects of endodontic treatment on apparent Young’s modulus of human teeth: in vitro study using speckle interferometry

Journal of Biomedical Optics, 2012

The introduction of new techniques for endodontic procedures requires the analysis of the biomech... more The introduction of new techniques for endodontic procedures requires the analysis of the biomechanical behavior of dental structures. Digital speckle shearing pattern interferometry (DSSPI) is a nondestructive optical measuring technique that allows one to directly quantify deformations in teeth that are subjected to stress. DSSPI technique was applied to measure small deformations caused by flexion in different types of teeth. The test was carried out both before and after endodontic treatment with the ProTaper method in order to evaluate the variation of dental elasticity, taking into the account the type of tooth and the endodontic treatment. The results obtained show that dental elasticity, established by means of the apparent Young's modulus, before and after the endodontic treatment, differs between incisors and premolars. The endodontic process does not affect dental elasticity (p>0.7). Specifically, 57.1% of central incisors and 56.3% of second premolars slightly increase their elasticity after the endodontic process. In turn, 42.9% of central incisors and 43.7% of second premolars slightly decrease elasticity. The endodontic treatment especially affects the "neutral fibre"; therefore, there is little influence on elasticity by flexion. However, after finishing the process, the channel was restored with material, which can slightly increase tooth elasticity in some cases.

Research paper thumbnail of Interferometric method for characterizing the smile of laser diode bars

Optics Communications, 2007

We propose an interferometric method for the characterization of the smile of laser diode bars (L... more We propose an interferometric method for the characterization of the smile of laser diode bars (LDBs). The LDB is placed in a Lloyd's mirror set-up. The beams coming from the LDB and its virtual image produce Young's fringes, which are captured by a charge-coupled-device array, digitised and saved in a computer as an irradiance matrix. The irradiance matrix is processed in the computer and the smile parameter extracted. The theoretical basis of the method is discussed and simulated fringe patterns of practical situations are presented. A device based on the described interferometric method was mounted and the smile of a commercially available LDB was characterised. Ó 2007 Published by Elsevier B.V.

Research paper thumbnail of "IN-VITRO" STUDY OF PIG BONE SAMPLES USING ELECTRICAL IMPEDANCE SPECTROSCOPY (EIS)

In this paper, an "in-vitro" study of bone samples using electrical impedance spectroscopy (EIS) ... more In this paper, an "in-vitro" study of bone samples using electrical impedance spectroscopy (EIS) is presented. The study was conducted using 30 samples prepared following a pathological procedure that eliminated Ca+2 ions from the samples and altered their porosity. The prepared samples were placed in a capacitor cell to measure the electrical impedance response in relation to the frequency through an HP4294A impedance bridge. These measurements were used to obtain Bode and Nyquist diagrams with which the equivalent RC circuit could be calculated for each of the samples using the Z-view software. The results indicate that there exist significant differences in the values of the electrical impedance module depending on the porosity levels and the loss of minerals in the samples studied. Additionally, the resulting equivalent electrical circuit made it possible to determine the average central frequency values to study the maximal sensitivity of porosity and mineral loss phenomena in our samples. These values were 1.81 MHz and 560 Hz, respectively. The significance of this study lies in the possibilities it presents to use the proposed technique to build non-invasive equipment to detect diseases such as osteoporosis. Advantages and disadvantages of the method used are discussed.

Research paper thumbnail of IN-VITRO STUDY OF BONE SAMPLES USING ELECTRICAL IMPEDANCE SPECTROSCOPY

In this paper an "in-vitro" study of bone samples using the electrical impedance spectroscopy (EI... more In this paper an "in-vitro" study of bone samples using the electrical impedance spectroscopy (EIS) is presented. The study was conducted using 30 samples prepared following a pathological procedure that eliminated Ca +2 ions from the samples and altered their porosity. The prepared samples were placed in a capacitor cell to measure the electrical impedance response in relation the frequency through an HP4294A impedance bridge. These measurements were used to obtain Bode and Nyquist diagrams with which the equivalent RC circuit could be calculated for each of the samples using the Z-view software. The results indicate that there exist significant differences in the values of the electrical impedance module depending on the porosity levels and the loss of minerals in the samples studied. Additionally, the resulting equivalent electrical circuit made it possible to determine the average central frequency values to study the maximal sensitivity of porosity and mineral loss phenomena in our samples, which were 1.81 MHz and 560 Hz, respectively. The significance of this study lies in the possibilities it presents to use the proposed technique to build non-invasive equipment to detect diseases such as osteoporosis. Advantages and disadvantages of the method used are discussed.