Wear of primary teeth caused by opposed all-ceramic or stainless steel crowns

PURPOSE: This study was conducted to evaluate the effects of full-coverage all-ceramic zirconia, lithium disilicate glass-ceramic, leucite glass-ceramic, or stainless steel crowns on antagonistic primary tooth wear. MATERIALS AND METHODS: There were four study groups: the stainless steel (Steel) group, the leucite glass-ceramic (Leucite) group, the lithium disilicate glass-ceramic (Lithium) group, and the monolithic zirconia (Zirconia) group. Ten flat crown specimens were prepared per group; opposing teeth were prepared using primary canines. A wear test was conducted over 100,000 chewing cycles using a dual-axis chewing simulator and a 50 N masticating force, and wear losses of antagonistic teeth and restorative materials were calculated using a three-dimensional profiling system and an electronic scale, respectively. Statistical significance was determined using One-way ANOVA and Tukey's test (P.05). CONCLUSION: Leucite glass-ceramic and lithium disilicate glass-ceramic cause more primary tooth wear than stainless steel or zirconia.

Malignant Hyperthermia under General Anesthetic Operation: A Case Report

Malignant hyperthermia is an inherited disorder of skeletal muscle, characterized by temperature elevation, muscle destruction, muscle rigidity and high oxygen consumption. It is triggered by anesthetic agents, usually potent inhalation anesthetics and succinylcholine. It is fatal in the majority of cases unless early diagnosis and treatment are performed. We experienced one case of malignant hyperthermia incidentally. She had post burn scar contracture on anterior chest and abdomen and local flap was prepared for releasing scar contracture under general anesthesia. Approximately 3 hours after induction, tachycardia developed followed by severe arrhythmia with unstable blood pressure, temperature elevation and cyanosis. Anesthesia was stopped immediately and aggressive emergency management was performed with Dantrolene. About 4 hours after induction, the patient was recovered to normal state with intensive care.