A Study on the DLC Film Coating for Improving Loosening Torque of Dental Implant Screw

치과 임플란트 스크루 풀림토크 개선용 DLC 박막 코팅에 관한 연구

  • Jeong, Woon-Jo (Dept. of Information Telecommunications, Chosun College of Science & Technology) ;
  • Cho, Jae-Cheol (Dept. of Electrical Engineering, DongShin University)
  • Received : 2018.07.02
  • Accepted : 2018.09.11
  • Published : 2018.10.01


In this paper, we studied coatings of the DLC thin film for improving loosening torque of dental implant screw. We used a filtered arc ion plating process which can realize the most dense DLC layer by coating the DLC thin film on the surface of the dental abutment screw. It showed both hardness comparable to diamond and low friction coefficient similar to graphite, and to improve the loosening phenomenon by increasing the screw tightening force Cr/CrN, Ti/TiN or Ti/TiN/Cr/CrN buffer layers were deposited for 5 to 10 minutes to improve the adhesion of the DLC thin film to the surface of the Ti (Gr.5), and then the DLC thin film was coated for about 15 minutes. As a result, the Cr/CrN buffer layer exhibited the highest hardness of 29.7 GPa, the adhesion of 18.62N on average, and a very low coefficient of friction of less than 0.2 as a whole. And we measured loosening torque after one million times with masticatory movement simulator. As a result, the values of the coated screw loosening torque were clearly higher than those of the uncoated screw. From this, it was found that the DLC coating was effective methods improving the loosening torque. In addition, it was confirmed that the cytotoxicity test and cell adhesion test showed high biocompatibility.


DLC;Loosening torque;Implant;Abutment screw;Filtered arc ion plating


Supported by : 동신대학교


  1. A. Khraisat, O. Abu-Hammad, N. Dar-Odeh, A.M.Al-Kayed, "Abutment Screw Loosening and Bending Resistance of External Hexagon Implant System after Lateral Cyclic Loading", Clinical Implant Dentistry and Related Research, Vol. 6, Issue 3 (2004), pp. 157-164.
  2. S. C. Kano, G. Bonfante, D. A. Curtis, "Effect of Casting Procedures on Screw Loosening in UCLA-Type Abutments", Journal of Prosthodontics, Vol. 15, Issue 2 (2006), pp. 77-81.
  3. D. Bordin, P.G. Coelho, E.T.P. Bergamo, E.A. Bonfante, L.Witek, A.Cury, "The Effect of DLC-Coating Deposition Method on the Reliability and Mechanical Properties of Abutment's Screws", Dental Materials, Vol. 34, Issue 6, (2018), pp. e128-e137.
  4. M.M. Olmedo, F.J.I. Godino, P.F. Lietor, F.A.C. Iglesias, "Corrosion and Fracture Analysis in Screws of Dental Implants Prostheses. New Coatings", Engineering Failure Analysis, Vol. 82, (2017), pp. 657-665.
  5. Y.Xie, J.Zhou, Q.Wei, Z.M.Yu, Z.G.Tang, "Improving the Long-Term Stability of Ti6Al4V Abutment Screw by Coating Micro/Nano-Crystalline Diamond Films", J. of the Mechanical Behavior of Biomedical Materials, Vol. 63, (2016), pp. 174-182.
  6. C.N. Elias, D.C. Figueira, P.R. Rios, "Influence of the Coating Material on the Loosing of Dental Implant Abutment Screw Joints", Materials Science and Engineering C, Vol. 26, Issue 8, (2006), pp. 1361-1366.
  7. H.C. Choe, C.H. Lee, Y.H. Jeong, Y.M. Ko, M.K. Son, C.H.Chung, "Fatigue Fracture of Implant System Using TiN and WC Coated Abutment Screw", Procedia Engineering, Vol. 10 (2011), pp. 680-685.
  8. D. Croccolo, M. De Agostinis, S. Fini, G. Olmi, "Tribological Properties of Bolts Depending on Different Screw Coatings and Lubrications:An Experimental Study", Tribology International, Vol. 107, (2017) pp. 199-205.
  9. D. Kapsokalyvas, M. V. Hoof, S. Wigren, T. Chimhanda, H. J. Kuijipers, F. C. S. Rmaekers, R. J. Stokroos, M. A. M. J. Zandv-oort, "Investigating the Race for the Surface and Skin Integration in Clinically Retrieved Abutments with Two-Photon Microscopy", Colloids and Surfaces B: Biointerfaces, Vol. 159 (2017), pp. 97-107.