질화타이타늄 코팅된 어버트먼트 나사를 사용한 임플란트 고정체의 피로파절 현상

Abstract

The purpose of this study was to investigate fatigue fracture phenomena of dental implant fixture used titanium nitride coated abutment screw under cyclic load. For the research of the fatigue fracture phenomena of dental fixture, TiN coated abutment screw(ShinHeung MST: TiN Screw RP/Luna), the fixture(Luna φ4.0 x 11.5mm), abutment(Duo Abut. φ4.5G/H2.0 H5.5 Hex) of internal hex type were prepared the each part of implant system used in this study for fatigue test after repeated loosening and tightening 5 times. After loosening and tightening, implant system was cut by diamond cutter for observation of fitness between fixture and abutment screw. The abutment surface and cross-sectional surface were observed using EDS and FE-SEM. For investigating of fatigue fracture of dental fixture, the fatigue test was carried out according to ISO 14801:2003(E) using tensile and compression tester (AG–10kNX, Shimadzu, Japan) with repeated load from 30% to 80% of static fracture force. And then fracture surface was observed by FE-SEM for fracture phenomena of dental fixture. 1. The fitness between abutment screw and fixture was improved in the case of TiN-coated abutment screw compared to non-coated abutment screw.

2. The fracture cycle drastically decreased as repeated load increased. Especially, in the case of TiN-coated abutment screw, fracture cycle increased compared to non-coated abutment screw.

3. The fatigue crack was propagated fast as repeated load increased, the step of striation increased from 0.5㎛/cycle to 2.0㎛/cycle for TiN-coated abutment screw, from 1.0㎛/cycle to 2.0㎛/cycle for non-coated abutment screw, as repeated load increased.

4. The plastic deformation region decreased, whereas, cleavage fracture region increased as repeated load increased. Especially, the plastic deformation region of TiN-coated abutment increased compared to non-coated abutment screw, whereas, cleavage fracture region decreased as repeated load increased.

In conclusion, it is considered that the fatigue characteristics and fitness between abutment screw and fixture can be improved by performing coating with TiN film on the surface of abutment screws.