The effect of surface texture on the retention of single implant-supported crowns cemented on wide-platform abutments

OBJECTIVE: This in vitro study evaluated the retention of copings cemented with a provisional cement and a permanent cement on wide-platform short abutments with different surface texture.METHODS: Two wide-platform abutments (height 4.0 mm) with machined (original) or modified surface (air-blasted with 50-µm aluminum oxide) were connected to two implant replicas under torque of 35 N.cm. Ten copings were cast in Cr-Co alloy from calcinable cylinders. Each coping was luted on the abutment under an axial force of 5 kg for 10 min, and the specimen was stored in a humid environment at 37°C for 20 h. After mechanical cycling simulating masticatory fatigue for 7 days (5754 cycles, 60 cycles/min, 200 N, 37°C), the specimens were subjected to a uniaxial tensile test at 0.5 cm/min, and the maximum retention strength (N) was recorded. After testing, the surfaces were cleaned, and the procedures were repeated for each coping in the experimental group. Data were analyzed by Student t test for paired samples. RESULTS: For the temporary cement, the mean retention (SD) was 36.1 (10.7) N for the machined surface and 49.6 (2.7) N for the blasted surface (P=0.004) (37% increase). For the zinc phosphate cement, the values were 292.0 (89.8) N and 440.6 (48.1) N, (P<0.001) (42% increase).CONCLUSION: The results suggest that the air-blasting of short and wide abutments increases the retention of the cast coping cemented with temporary or permanent cement.