IADR Abstract Archives
Wear resistance of CAD/CAM glass ceramic blocks
Objectives: CAD/CAM ceramic blocks have become popular as materials for dental restoration, and used widely. High physical properties and chemical durability are required for the restorative materials because such properties affect longevity of restorations. Recently, a new lithium-disilicate glass-ceramic CAD/CAM block, Initial LiSi block, was developed by GC Corporation. The aim of this study was to evaluate the wear resistance of the glass-ceramic blocks for CAD/CAM.
Methods: Specimen (φ2.1 mm) were made by two kinds of materials, Initial LiSi block: LIS (GC) and IPS e.max CAD: EMA (Ivoclar Vivadent). The specimens of EMA were heat-treated for crystallization following the manufacturer’s instructions. All specimens were polished with Cera Shine (GC). They were attached to the testing machine and contacted with Hydroxyapatite (HAp) as antagonist in water. Two-body wear test was performed with sliding movement to the contact surface of the specimen for 10,000 cycles. Wear amount of the materials was calculated from height measurement of the specimen before and after the test. The data was analyzed by one-way ANOVA and t-test (p< 0.01). After the wear test, surface properties were observed with laser microscope and scanning electron microscope (SEM).
Results: Results of the wear test were shown in Table. After the test, abrasion loss of the materials for both glass-ceramic blocks was confirmed. However, the wear amount of LIS was significantly lower than that of EMA. The abrasion depth of HAp (vs LIS) was also shallower than that of HAp (vs EMA) (p< 0.01).
Conclusions: In this study, it is suggested that Initial LiSi block has high wear resistance property and low risk of damage to antagonistic tooth.
Methods: Specimen (φ2.1 mm) were made by two kinds of materials, Initial LiSi block: LIS (GC) and IPS e.max CAD: EMA (Ivoclar Vivadent). The specimens of EMA were heat-treated for crystallization following the manufacturer’s instructions. All specimens were polished with Cera Shine (GC). They were attached to the testing machine and contacted with Hydroxyapatite (HAp) as antagonist in water. Two-body wear test was performed with sliding movement to the contact surface of the specimen for 10,000 cycles. Wear amount of the materials was calculated from height measurement of the specimen before and after the test. The data was analyzed by one-way ANOVA and t-test (p< 0.01). After the wear test, surface properties were observed with laser microscope and scanning electron microscope (SEM).
Results: Results of the wear test were shown in Table. After the test, abrasion loss of the materials for both glass-ceramic blocks was confirmed. However, the wear amount of LIS was significantly lower than that of EMA. The abrasion depth of HAp (vs LIS) was also shallower than that of HAp (vs EMA) (p< 0.01).
Conclusions: In this study, it is suggested that Initial LiSi block has high wear resistance property and low risk of damage to antagonistic tooth.
