A Study of mechanical properties of oxide layer removed Co-Cr-Mo abutments

Ryu,  Jae-ho; Huh,  Jung-Bo; Ro,  Jung-Hoon; Yun,  Mi-Jung; Jeong,  Chang-Mo

J Korean Dent Assoc > Volume 53(11); 2015 > Article

The Journal of The Korean Dental Association 2015;53(11):804-816.
Published online November 30, 2015.

A Study of mechanical properties of oxide layer removed Co-Cr-Mo abutments

Jae-ho Ryu¹, Jung-Bo Huh², Jung-Hoon Ro³, Mi-Jung Yun⁴, Chang-Mo Jeong⁵

¹Department of Interdisciplinary Program in Biomedical Engineering, Pusan National University
²Department of Prosthodontics, School of Dentistry, Dental Research Institute, Pusan National University Dental Hospital, Pusan National University
³Department of Interdisciplinary Program in Biomedical Engineering, Pusan National University
⁴Department of Prosthodontics, School of Dentistry, Dental Research Institute, Pusan National University Dental Hospital, Pusan National University
⁵Department of Prosthodontics, School of Dentistry, Dental Research Institute, Pusan National University Dental Hospital, Pusan National University

Abstract

PURPOSE
The aim of this study was to evaluate the influence of the oxide layer removal process in the Co-Cr-Mo (CCM) abutment after casting procedure on the prosthesis settlement and screw stability. MATERIALS AND METHODS: CCM abutments of four different interface conditions (CCM-M; machined, CCM-O; oxide layer formed, CCM-B; blasted, CCM-P; polished after blasted) and gold abutment (Gold-C; Cast with type III Gold alloy) were used. The initial settling values of abutments were evaluated according to the difference of implant-abutment length when the tightening torques were applied at 5 Ncm and 30 Ncm, and the settling values of abutments caused by loading were evaluated according to the difference of implant-abutment length before and after loading with 250 N, 100000 cycle. The loss ratios of removal torque for abutment screws were evaluated according to the difference in value of removal torques under 30 Ncm tightening torque applied before and after cyclic loading. RESULTS: The CCM-P and CCM-B group showed a higher initial settling value compared with the Gold-C group (P<.05), while the Gold-C group showed the highest settling values caused by loading (P<.05) and no significant differences were observed for between CCM groups (P>.05). The loss ratio of removal torque values for the CCM-B, CCM-P groups did not differ significantly from that of the Gold-C group (P>.05). CONCLUSION: Even though the oxide layer was removed by different methods, CCM abutment with internal conical connection structure showed lower abutment settling and similar screw loosening after cyclic loading compared with gold abutment.

Key Words: UCLA abutment;Gold abutment;CCM abutment;Oxide layer;Settling: Screw loosening;