IADR Abstract Archives
Retention of zirconia copings luted with self-adhesive resin cements
Objectives: To measure the tensile strength of zirconia copings cemented with different cements following thermocycling.
Methods: 60 extracted non-carious mandibular premolar teeth were mounted in acrylic filled cylinders. The teeth were prepared to uniform dimensions (20° total taper) and 3.5mm preparation height using a flat-end tapered diamond bur (846.11.025HP, Brasseler). The surface area of the prepared surface was calculated with digital microscopy. The teeth were scanned with a True Definition Scanner (3M). Zirconia crowns (Lava Plus, 3M) were milled and sintered following manufacturers recommendations. The intaglio surfaces were sandblasted with 30 micron alumina at 2 bar for 10 seconds. The crowns (n=10) were then cemented with either an Experimental Cement (3M), RelyX Unicem 2 (3M), Panavia SA Cement Plus (Kuraray), Maxcem Elite Chroma (Kerr), Calibra Universal (Dentsply), or SpeedCEM Plus (Ivoclar) cement. No primers were used on the crowns or teeth. Crowns were allowed to self-cure under a 2.5 kg weight, stored in a moist bag for 24 hours at 37°C and then thermocycled for 10,000cycles from 5-500C with a 30 second dwell time. The specimens were placed in a custom fixture in a universal testing machine and loaded in tension at a crosshead speed of 5mm/min until debonding. The tensile strength (MPa) at debonding was calculated using the maximum recorded tensile force and surface area of the preparation. Data were compared with a 1-way ANOVA and Tukey analysis (alpha=0.05).
Results: Significant differences between cements were noted with 1-way ANOVA (p<.01). Materials can be categorized into significantly different groups with Tukey analysis as represented by the letters in the chart below.
Conclusions: Experimental Cement and Panavia SA Cement Plus showed significantly higher tensile strength/retention than Maxcem Elite Chroma, Calibra Universal and SpeedCEM Plus. RelyX Unicem 2 shared the same statistical group with the Experimental Cement, Panavia SA Cement Plus and with SpeedCEM Plus.
Methods: 60 extracted non-carious mandibular premolar teeth were mounted in acrylic filled cylinders. The teeth were prepared to uniform dimensions (20° total taper) and 3.5mm preparation height using a flat-end tapered diamond bur (846.11.025HP, Brasseler). The surface area of the prepared surface was calculated with digital microscopy. The teeth were scanned with a True Definition Scanner (3M). Zirconia crowns (Lava Plus, 3M) were milled and sintered following manufacturers recommendations. The intaglio surfaces were sandblasted with 30 micron alumina at 2 bar for 10 seconds. The crowns (n=10) were then cemented with either an Experimental Cement (3M), RelyX Unicem 2 (3M), Panavia SA Cement Plus (Kuraray), Maxcem Elite Chroma (Kerr), Calibra Universal (Dentsply), or SpeedCEM Plus (Ivoclar) cement. No primers were used on the crowns or teeth. Crowns were allowed to self-cure under a 2.5 kg weight, stored in a moist bag for 24 hours at 37°C and then thermocycled for 10,000cycles from 5-500C with a 30 second dwell time. The specimens were placed in a custom fixture in a universal testing machine and loaded in tension at a crosshead speed of 5mm/min until debonding. The tensile strength (MPa) at debonding was calculated using the maximum recorded tensile force and surface area of the preparation. Data were compared with a 1-way ANOVA and Tukey analysis (alpha=0.05).
Results: Significant differences between cements were noted with 1-way ANOVA (p<.01). Materials can be categorized into significantly different groups with Tukey analysis as represented by the letters in the chart below.
Conclusions: Experimental Cement and Panavia SA Cement Plus showed significantly higher tensile strength/retention than Maxcem Elite Chroma, Calibra Universal and SpeedCEM Plus. RelyX Unicem 2 shared the same statistical group with the Experimental Cement, Panavia SA Cement Plus and with SpeedCEM Plus.