IADR Abstract Archives
Calcium-Release and Bond-Strength of New Self-Adhesive Resin-Cement Under Acidic Environment
Objectives: The purpose of this study was to evaluate bond durability and calcium-release of a calcium-releasing self-adhesive resin cement (TheraCem) and the control (RelyX UniCem2) under severely acidic condition (pH 2.4).
Methods: Yttria-stabilized zirconia ceramic was sandblasted with alumina sand, rinsed and dried. Shear bond strength was tested using the notched-edge shear bond strength test method (ISO 29022:2013). Self-adhesive cement (TheraCem, Bisco; or RelyX UniCem2, 3M Oral) was placed on the substrate surface and self-polymerized (15 minutes/37°C). The specimens were then stored in either deionized water (Control) or acidic lactic acid solution (0.1N, pH 2.3~2.4) at 37°C/7 days and tested by universal testing machine (Instron, crosshead-speed 1mm/min). The debonded surface of each cement specimen was examined under SEM. The data were analyzed statistically by one-way ANOVA and Student-t Test. Calcium releases were measured on calcium-releasing self-adhesive cement, TheraCem. Disks were prepared (2cm-diameter and 0.1cm-high) with the cement, and self-cured for 15 min/37°C. Disks were then stored in 20ml of deionized water or acidic lactic acid solution (0.1N, pH 2.3~2.4) at 37°C. Release of ions was measured on Orion Model 710A+ after 1 day, 5 days and 7 days with new deionized water or lactic acid solution being replenished after each test.
Results: Results are in showed Table 1 and Table 2. SEM showed that TheraCem had similar patterns of bonding failures in deionized water and acidic solution. UniCem2’s bonding failure in acidic solution was mainly due to the degradation of its margin.
Conclusions: Under the severely acidic condition, calcium releasing self-adhesive resin cement, TheraCem, release 5 times higher of calcium. The bond strength of TheraCem after aging under acidic condition was the same as aging in deionized water, while the control self-adhesive resin cement had 37% lower of bond strength.
Methods: Yttria-stabilized zirconia ceramic was sandblasted with alumina sand, rinsed and dried. Shear bond strength was tested using the notched-edge shear bond strength test method (ISO 29022:2013). Self-adhesive cement (TheraCem, Bisco; or RelyX UniCem2, 3M Oral) was placed on the substrate surface and self-polymerized (15 minutes/37°C). The specimens were then stored in either deionized water (Control) or acidic lactic acid solution (0.1N, pH 2.3~2.4) at 37°C/7 days and tested by universal testing machine (Instron, crosshead-speed 1mm/min). The debonded surface of each cement specimen was examined under SEM. The data were analyzed statistically by one-way ANOVA and Student-t Test. Calcium releases were measured on calcium-releasing self-adhesive cement, TheraCem. Disks were prepared (2cm-diameter and 0.1cm-high) with the cement, and self-cured for 15 min/37°C. Disks were then stored in 20ml of deionized water or acidic lactic acid solution (0.1N, pH 2.3~2.4) at 37°C. Release of ions was measured on Orion Model 710A+ after 1 day, 5 days and 7 days with new deionized water or lactic acid solution being replenished after each test.
Results: Results are in showed Table 1 and Table 2. SEM showed that TheraCem had similar patterns of bonding failures in deionized water and acidic solution. UniCem2’s bonding failure in acidic solution was mainly due to the degradation of its margin.
Conclusions: Under the severely acidic condition, calcium releasing self-adhesive resin cement, TheraCem, release 5 times higher of calcium. The bond strength of TheraCem after aging under acidic condition was the same as aging in deionized water, while the control self-adhesive resin cement had 37% lower of bond strength.