Parosteal osteosarcoma (POS) is the most common form of surface osteosarcoma. Its symptoms are insidious and its duration prior to diagnosis is considerably longer than that of other types of osteosarcoma. We report a case of POS with a growing mass but no evidence of metastasis. This tumor, which was diagnosed as calcified hematoma with benign characteristics, was incompletely resected in our hospital 21 years before the diagnosis of recurrence. The patient underwent a wide en bloc resection in our hospital and was free of symptoms, with no signs of tumor recurrence or metastasis during a 53-month follow-up.
Adult ; Bone Neoplasms ; diagnosis ; pathology ; surgery ; Diagnostic Errors ; Follow-Up Studies ; Humans ; Humerus ; Magnetic Resonance Imaging ; Male ; Neoplasm Recurrence, Local ; Osteosarcoma, Juxtacortical ; diagnosis ; pathology ; surgery ; Radiopharmaceuticals ; Technetium Tc 99m Medronate ; Tomography, Emission-Computed ; Tomography, X-Ray Computed

PURPOSE: This study aimed to compare the microshear bond strength (µSBS) of dual-cure resin cement in CAD-CAM zirconia after different cleaning techniques. MATERIALS AND METHODS: Fifty discs of zirconia-based ceramic from Ivoclar Vivadent were embedded in acrylic resin. The discs were divided into five groups according to the cleaning methods: used: Group 1: drying with spraying + sandblasting with Al2O3 ; Group 2: washed with water and dried with spraying + sandblasting with Al2O 3 ; Group 3: washed with distilled water and dried with spraying + sandblasting with Al2O3 + zirconium oxide (Ivoclean); Group 4: washed with distilled water and dried with spraying + sandblasting with Al2O3 + potassium hydroxide (Zirclean); and Group 5: washed with distilled water and dried with spraying + sandblasting with Al2O3 + 1% NaClO. All of the groups were contaminated with artificial saliva for 1 minute and then cleaned. Statistical analyses were performed using ANOVA and Tukey’s tests. RESULTS: There were statistically significant differences among all groups for µSBS (P < .05). The group treated with zirconium oxide (Group 3) showed the highest µSBS (18.75 ± 0.23 MPa). CONCLUSION When applied to zirconia, the cleaning methods affected the bonding with resin cement differently.

PURPOSE: This study aimed to compare the microshear bond strength (µSBS) of dual-cure resin cement in CAD-CAM zirconia after different cleaning techniques. MATERIALS AND METHODS: Fifty discs of zirconia-based ceramic from Ivoclar Vivadent were embedded in acrylic resin. The discs were divided into five groups according to the cleaning methods: used: Group 1: drying with spraying + sandblasting with Al2O3 ; Group 2: washed with water and dried with spraying + sandblasting with Al2O 3 ; Group 3: washed with distilled water and dried with spraying + sandblasting with Al2O3 + zirconium oxide (Ivoclean); Group 4: washed with distilled water and dried with spraying + sandblasting with Al2O3 + potassium hydroxide (Zirclean); and Group 5: washed with distilled water and dried with spraying + sandblasting with Al2O3 + 1% NaClO. All of the groups were contaminated with artificial saliva for 1 minute and then cleaned. Statistical analyses were performed using ANOVA and Tukey’s tests. RESULTS: There were statistically significant differences among all groups for µSBS (P < .05). The group treated with zirconium oxide (Group 3) showed the highest µSBS (18.75 ± 0.23 MPa). CONCLUSION When applied to zirconia, the cleaning methods affected the bonding with resin cement differently.