بررسی تاثیرخشونت سطحی اباتمنت بر میزان استحکام گیر رستوریشنهای سمان شونده متکی بر ایمپلنت با سمان موقتی

 Background and Objective: Surface roughness can increase the retention of castings by sandblast that are micro retentive. This study compared the retention of implant-supported crowns when used with 3 different surface roughness abutments and one temporary cement.  Materials and Methods: Thirty abutments (DIO implant- Cemented abutment,SAC 4814N(II)) were divided in three groups, first group was standard machine surface, second group sandblasted with 25 micron aluminum oxide particles and third group was sandblasted with 50 micron than ten regular diameter implant analogs were embedded in resin acrylic block and provisional cement kerr Temp bond NE was used for cementation.90 metal coping were fabricated and after cementation the aging processing was done than the retentive strength was tested with universal testing machine at cross head speed of 0.5 mm/min, results were analyzed using One way ANOVA and Tukey test.   Results: Retentive strength of temp bond kerr with 50 micro sanbblasted abutment was statistically different than two other groups(P<0.001) .and between all the group standard abutment was weakest.   Conclusion: Surface modification of implant abutment by sandblast may be an effective method to increase retention of crown when provisional luting cement is used.