We are using cookies to implement functions like login, shopping cart or language selection for this website. Furthermore we use Google Analytics to create anonymized statistical reports of the usage which creates Cookies too. You will find more information in our privacy policy.
OK, I agree I do not want Google Analytics-Cookies
The International Journal of Oral & Maxillofacial Implants
Login:
username:

password:

Plattform:

Forgotten password?

Registration

Int J Oral Maxillofac Implants 31 (2016), No. 4     22. July 2016
Int J Oral Maxillofac Implants 31 (2016), No. 4  (22.07.2016)

Page 813-819, doi:10.11607/jomi.4173, PubMed:27447147


Removal Torque and Biofilm Accumulation at Two Dental Implant-Abutment Joints After Fatigue
Pereira, Jorge / Morsch, Carolina S. / Henriques, Bruno / Nascimento, Rubens M. / Benfatti, Cesar A. M. / Silva, Filipe S. / López-López, José / Souza, Júlio C. M.
Purpose: The aim of this study was to evaluate the removal torque and in vitro biofilm penetration at Morse taper and hexagonal implant-abutment joints after fatigue tests.
Materials and Methods: Sixty dental implants were divided into two groups: (1) Morse taper and (2) external hexagon implant-abutment systems. Fatigue tests on the implant-abutment assemblies were performed at a normal force (FN) of 50 N at 1.2 Hz for 500,000 cycles in growth medium containing human saliva for 72 hours. Removal torque mean values (n = 10) were measured after fatigue tests. Abutments were then immersed in 1% protease solution in order to detach the biofilms for optical density and colony-forming unit (CFU/cm2) analyses. Groups of implant-abutment assemblies (n = 8) were cross-sectioned at 90 degrees relative to the plane of the implant-abutment joints for the microgap measurement by field-emission guns scanning electron microscopy.
Results: Mean values of removal torque on abutments were significantly lower for both Morse taper (22.1 ± 0.5 μm) and external hexagon (21.1 ± 0.7 μm) abutments after fatigue tests than those recorded without fatigue tests (respectively, 24 ± 0.5 μm and 24.8 ± 0.6 μm) in biofilm medium for 72 hours (P = .04). Mean values of microgap size for the Morse taper joints were statistically signicantly lower without fatigue tests (1.7 ± 0.4 μm) than those recorded after fatigue tests (3.2 ± 0.8 μm). Also, mean values of microgap size for external hexagon joints free of fatigue were statistically signicantly lower (1.5 ± 0.4 μm) than those recorded after fatigue tests (8.1 ± 1.7 μm) (P < .05). The optical density of biofilms and CFU mean values were lower on Morse taper abutments (Abs630nm at 0.06 and 2.9 × 104 CFU/cm2) than that on external hexagon abutments (Abs630nm at 0.08 and 4.5 × 104 CFU/cm2) (P = .01).
Conclusion: The mean values of removal torque, microgap size, and biofilm density recorded at Morse taper joints were lower in comparison to those recorded at external hexagon implant-abutment joints after fatigue tests in a simulated oral environment for 72 hours.

Keywords: biofilms, dental implants, fatigue, implant-abutment, removal torque