RESUMEN
PURPOSE@#The purpose of this study was to investigate changes in retention and wear pattern of Locator® and ADD-TOC attachments on a digital milled bar by performing chewing simulation and repeated insertion/removal of prostheses in fully edentulous models. @*MATERIALS AND METHODS@#Locator (Locator®; Zest Anchors Inc., Escondido, CA, USA) was selected as the control group and ADD-TOC (ADDTOC; PNUAdd Co., Ltd., Busan, Republic of Korea) as the experimental group. A CAD-CAM milled bar was mounted on a master model and 3 threaded holes for connecting a bar attachment was formed using a tap. Locator and ADD-TOC attachments were then attached to the milled bar. Simulated mastication and repeated insertion/removal were performed over 400,000 cyclic loadings and 1,080insertions/removals, respectively. Wear patterns on deformed attachment were investigated by field emission scanning electron microscopy. @*RESULTS@#For the ADD-TOC attachments, chewing simulation and repeated insertion/removal resulted in a mean initial retentive force of 24.43 ± 4.89 N, which were significantly lower than that of the Locator attachment, 34.33 ± 8.25 N (P < .05). Amounts of retention loss relative to baseline for the Locator and ADD-TOC attachments were 21.74 ± 7.07 and 8.98 ± 5.76 N (P < .05). @*CONCLUSION@#CAD-CAM milled bar with the ADD-TOC attachment had a lower initial retentive force than the Locator attachment. However, the ADD-TOC attachment might be suitable for long-term use as it showed less deformation and had a higher retentive force after simulated mastication and insertion/removal repetitions.
RESUMEN
Purpose@#The aim of this study was to evaluate the effects of four surface treatment methods to improve zirconia roughness and three types of resin cement on the shear bond strength (SBS). @*Materials and methods@#A total of 120 zirconia blocks were randomly divided into four surface treatments: non-treatment (Control), airborne-particle abrasion (APA) with 50 μm Al2O3 (APA50), APA with 125 μm Al2O3(APA125), and ZrO2 slurry (ZA). Three resin cements (Panavia F 2.0, Superbond C&B, and Variolink N) were applied to the surface-treated zirconia specimens. All specimens were subjected to SBS testing using a universal testing machine. The surface of the representative specimens of each group was observed by scanning electron microscope (SEM). SBS data were analyzed with oneway ANOVA, two-way ANOVA test and post-hoc Tukey HSD Test (α=.05). @*Results@#In the surface treatment method, APA125, APA50, ZA, and Control showed high shear bond strength in order, but there was no significant difference between APA125 and APA50 (P >.05). Also, ZA showed significantly higher shear bond strength than Control (P <.05). In the resin cement type, Panavia F 2.0, Superbond C&B, and Variolink N showed significantly higher shear bond strength in order (P <.05). In SEM images, the zirconia surfaces of the APA50 and APA125 showed quite rough and irregular shapes, and the zirconia surface of the ZA was observed small irregular porosity and rough surfaces. @*Conclusion@#APA and ZrO 2 slurry were enhanced the surface roughness of zirconia, and Panavia F 2.0 containing MDP showed the highest shear bond strength with zirconia.
RESUMEN
Purpose@#The aim of this study was to evaluate the effects of four surface treatment methods to improve zirconia roughness and three types of resin cement on the shear bond strength (SBS). @*Materials and methods@#A total of 120 zirconia blocks were randomly divided into four surface treatments: non-treatment (Control), airborne-particle abrasion (APA) with 50 μm Al2O3 (APA50), APA with 125 μm Al2O3(APA125), and ZrO2 slurry (ZA). Three resin cements (Panavia F 2.0, Superbond C&B, and Variolink N) were applied to the surface-treated zirconia specimens. All specimens were subjected to SBS testing using a universal testing machine. The surface of the representative specimens of each group was observed by scanning electron microscope (SEM). SBS data were analyzed with oneway ANOVA, two-way ANOVA test and post-hoc Tukey HSD Test (α=.05). @*Results@#In the surface treatment method, APA125, APA50, ZA, and Control showed high shear bond strength in order, but there was no significant difference between APA125 and APA50 (P >.05). Also, ZA showed significantly higher shear bond strength than Control (P <.05). In the resin cement type, Panavia F 2.0, Superbond C&B, and Variolink N showed significantly higher shear bond strength in order (P <.05). In SEM images, the zirconia surfaces of the APA50 and APA125 showed quite rough and irregular shapes, and the zirconia surface of the ZA was observed small irregular porosity and rough surfaces. @*Conclusion@#APA and ZrO 2 slurry were enhanced the surface roughness of zirconia, and Panavia F 2.0 containing MDP showed the highest shear bond strength with zirconia.