Abstract
The purpose of this study was to determine whether or not colored fluids and microorganism is microleakage along the implant-abutment interface of Non-Hexed and externally-Hexed lock (HL) Steri-Oss implant systems. Furthermore, an attempt was made to find measures against such microleakage.
The degrees of microleakage in the implant were examined when the implant-abutment assembly was closed by 10 Ncm and 20 Ncm torques. As a tracer, a plaque disclosing solution and gram-negative anaerobic short rod-shaped bacteria (Bacilli) isolated from plaque around the apical roots of extracted teeth were used. The experiment on microleakage was carried out by immersing the implant-abutment assembly into a test tube containing the solution and a BHI (brain heart infusion) broth.
In tests using the plaque disclosing agent, microleakage from the implant-abutment interface to the implant substructure decreased significantly as the closing torque was increased from 10 Ncm to 20 Ncm. However, the difference in implant type between Non-Hexed and HL implant systems did not affect liquid leakage much. The microorganisms were seen invading the inside of the implant-abutment assembly, but no significant changes in microleakage were observed even if the closing torque was increased from 10 Ncm to 20 Ncm, the implant system was changed from the Non-Hexed to the HL system, or if ultrasound vibrations were applied to the test tube or not. While three types of sealers containing 1.8% CHX(chlorhexidene) ointment were inserted between the implant and abutment while closing the assembly by a torque of 20 Ncm, leakages of microorganisms were mostly prevented.
These results demonstrated that it is possible to prevent microleakage from the interface by using sealers in addition to tightly closing the implant-abutment assembly with the torque when the implant is connected with the abutment.
