IADR Abstract Archives
Optical Coherence Tomography for Monitoring of Fatigue Damage in CAD/CAM-crowns
Objectives: Today, several materials are available for the manufacturing of monolithic posterior computer-aided-designed/computer-aided-manufactured (CAD/CAM) crowns. Previous studies showed different fatigue damage of CAD/CAM-materials after artificial ageing in a mouth-motion-simulator. However, most methods go along with the destruction of test specimen, so that only a single examination is possible. Thus, it was the aim of this in vitro study, to use a method, which allows a monitoring of fatigue damage over time such as optical coherence tomography (OCT).
Methods: Therefore, forty-eight CAD/CAM-manufactured crowns (8x Lava Plus (LP), 8x Pritidenta multidisc (PM), 8x Prettau anterior (PA), 8x Celtra Duo (CD), 8x Vita Enamic (VE), 8x Brilliant Crios (BC)) were adhesively luted on CAD/CAM-milled human molars with their corresponding luting system. Following, specimens were loaded in a mouth-motion-simulator (50-500N, 2Hz, 37°C) for 1 million cycles. Before loading and every 250,000 cycles, specimens were analysed with a spectral domain (SD)-OCT (RS-3000). For the investigation the maximum vertical damage were measured with imaging-processing-software (ImageJ). In addition specimens were sliced and the length of damage area [µm] was assessed with a light microscope (Zeiss). Results of the new OCT method were compared to the established light microscope method. Statistical analysis was performed by ANCOVA and 2x4-ANOVA.
Results: All specimens (except for LP and PM) showed a linear increase and a significant difference of fatigue damage over time (p< .05). CD showed the highest damage (mean, confidence interval: 380µm, 290-420µm) followed by VE (120µm, 88-130µm), BC (80µm, 55-88µm) and PA (.0µm, .0-5.6µm). Furthermore, damage was found in PA specimen only after 750,000 cycles mouth-motion-simulation, while in all others damage already occurred after 250,000 cycles.
Conclusions: Overall, the results demonstrate that OCT is a feasible analyzation method for monitoring of fatigue damage over time in different CAD/CAM-materials.
Methods: Therefore, forty-eight CAD/CAM-manufactured crowns (8x Lava Plus (LP), 8x Pritidenta multidisc (PM), 8x Prettau anterior (PA), 8x Celtra Duo (CD), 8x Vita Enamic (VE), 8x Brilliant Crios (BC)) were adhesively luted on CAD/CAM-milled human molars with their corresponding luting system. Following, specimens were loaded in a mouth-motion-simulator (50-500N, 2Hz, 37°C) for 1 million cycles. Before loading and every 250,000 cycles, specimens were analysed with a spectral domain (SD)-OCT (RS-3000). For the investigation the maximum vertical damage were measured with imaging-processing-software (ImageJ). In addition specimens were sliced and the length of damage area [µm] was assessed with a light microscope (Zeiss). Results of the new OCT method were compared to the established light microscope method. Statistical analysis was performed by ANCOVA and 2x4-ANOVA.
Results: All specimens (except for LP and PM) showed a linear increase and a significant difference of fatigue damage over time (p< .05). CD showed the highest damage (mean, confidence interval: 380µm, 290-420µm) followed by VE (120µm, 88-130µm), BC (80µm, 55-88µm) and PA (.0µm, .0-5.6µm). Furthermore, damage was found in PA specimen only after 750,000 cycles mouth-motion-simulation, while in all others damage already occurred after 250,000 cycles.
Conclusions: Overall, the results demonstrate that OCT is a feasible analyzation method for monitoring of fatigue damage over time in different CAD/CAM-materials.