1.Biomechanical behavior of CAD/CAM cobaltchromium and zirconia full-arch fixed prostheses
Thaís BARBIN ; Letícia Del Rio SILVA ; Daniele Valente VELÔSO ; Guilherme Almeida BORGES ; Anna Gabriella Camacho PRESOTTO ; Valentim Adelino Ricardo BARÃO ; Francisco Carlos GROPPO ; Marcelo Ferraz MESQUITA
The Journal of Advanced Prosthodontics 2020;12(6):329-337
PURPOSE:
To verify the influence of computer-aided design/computer-aided manufacturing (CAD/CAM) implantsupported prostheses manufactured with cobalt-chromium (Co-Cr) and zirconia (Zr), and whether ceramic application, spark erosion, and simulation of masticatory cycles modify biomechanical parameters (marginal fit, screw-loosening torque, and strain) on the implant-supported system.
MATERIALS AND METHODS:
Ten full-arch fixed frameworks were manufactured by a CAD/CAM milling system with Co-Cr and Zr (n=5/group). The marginal fit between the abutment and frameworks was measured as stated by single-screw test. Screw-loosening torque evaluated screw stability, and strain analysis was explored on the implant-supported system. All analyses were performed at 3 distinct times: after framework manufacturing; after ceramic application in both materials’ frameworks; and after the spark erosion in Co-Cr frameworks. Afterward, stability analysis was re-evaluated after 10 6 mechanical cycles (2 Hz/150-N) for both materials. Statistical analyses were performed by Kruskal-Wallis and Dunn tests (α=.05).
RESULTS:
No difference between the two materials was found for marginal fit, screwloosening torque, and strain after framework manufacturing (P>.05). Ceramic application did not affect the variables (P>.05). Spark erosion optimized marginal fit and strain medians for Co-Cr frameworks (P<.05). Screwloosening torque was significantly reduced by masticatory simulation (P<.05) regardless of the framework materials.
CONCLUSION
Co-Cr and Zr frameworks presented similar biomechanical behavior. Ceramic application had no effect on the biomechanical behavior of either material. Spark erosion was an effective technique to improve Co-Cr biomechanical behavior on the implant-supported system. Screw-loosening torque was reduced for both materials after masticatory simulation.
2.Biomechanical behavior of CAD/CAM cobaltchromium and zirconia full-arch fixed prostheses
Thaís BARBIN ; Letícia Del Rio SILVA ; Daniele Valente VELÔSO ; Guilherme Almeida BORGES ; Anna Gabriella Camacho PRESOTTO ; Valentim Adelino Ricardo BARÃO ; Francisco Carlos GROPPO ; Marcelo Ferraz MESQUITA
The Journal of Advanced Prosthodontics 2020;12(6):329-337
PURPOSE:
To verify the influence of computer-aided design/computer-aided manufacturing (CAD/CAM) implantsupported prostheses manufactured with cobalt-chromium (Co-Cr) and zirconia (Zr), and whether ceramic application, spark erosion, and simulation of masticatory cycles modify biomechanical parameters (marginal fit, screw-loosening torque, and strain) on the implant-supported system.
MATERIALS AND METHODS:
Ten full-arch fixed frameworks were manufactured by a CAD/CAM milling system with Co-Cr and Zr (n=5/group). The marginal fit between the abutment and frameworks was measured as stated by single-screw test. Screw-loosening torque evaluated screw stability, and strain analysis was explored on the implant-supported system. All analyses were performed at 3 distinct times: after framework manufacturing; after ceramic application in both materials’ frameworks; and after the spark erosion in Co-Cr frameworks. Afterward, stability analysis was re-evaluated after 10 6 mechanical cycles (2 Hz/150-N) for both materials. Statistical analyses were performed by Kruskal-Wallis and Dunn tests (α=.05).
RESULTS:
No difference between the two materials was found for marginal fit, screwloosening torque, and strain after framework manufacturing (P>.05). Ceramic application did not affect the variables (P>.05). Spark erosion optimized marginal fit and strain medians for Co-Cr frameworks (P<.05). Screwloosening torque was significantly reduced by masticatory simulation (P<.05) regardless of the framework materials.
CONCLUSION
Co-Cr and Zr frameworks presented similar biomechanical behavior. Ceramic application had no effect on the biomechanical behavior of either material. Spark erosion was an effective technique to improve Co-Cr biomechanical behavior on the implant-supported system. Screw-loosening torque was reduced for both materials after masticatory simulation.
3.The neuroprotective effect of traditional Chinese medicinal plants-A critical review.
João MOREIRA ; Mariana MACHADO ; Mónica DIAS-TEIXEIRA ; Ricardo FERRAZ ; Cristina DELERUE-MATOS ; Clara GROSSO
Acta Pharmaceutica Sinica B 2023;13(8):3208-3237
Neurodegenerative and neuropsychiatric diseases are increasingly affecting individuals' quality of life, thus increasing their cost to social and health systems. These diseases have overlapping mechanisms, such as oxidative stress, protein aggregation, neuroinflammation, neurotransmission impairment, mitochondrial dysfunction, and excitotoxicity. Currently, there is no cure for neurodegenerative diseases, and the available therapies have adverse effects and low efficacy. For neuropsychiatric disorders, such as depression, the current therapies are not adequate to one-third of the patients, the so-called treatment-resistant patients. So, searching for new treatments is fundamental. Medicinal plants appear as a strong alternative and complement towards new treatment protocols, as they have been used for health purposes for thousands of years. Thus, the main goal of this review is to revisit the neuroprotective potential of some of the most predominant medicinal plants (and one fungus) used in traditional Chinese medicine (TCM), focusing on their proven mechanisms of action and their chemical compositions, to give clues on how they can be useful against neurodegeneration progression.