Bacterial microleakage at the implant-abutment interface in Morse taper implants

Abstract

Aim: To evaluate the microleakage at the implant-abutment (I-A) interface of Morse tapered implants inoculated with different volumes of bacterial suspension. Methods: Morse tapered I-A sets were selected and divided in two groups depending on the type of abutment: passing screw (PS) and solid (S), and then subdivided into four subgroups (n=6) according to the suspension volume: PS1: 0.1 µL; PS3: 0.3 µL; PS5: 0.5 µL; PS7: 0.7 µL; S1: 0.1 µL; S3: 0.3 µL; S5: 0.5 µL and S7: 0.7 µL. A control test was performed to verify the presence of external contamination during the inoculation and the implants were incubated for microbiological analysis. The microleakage was evaluated every 24 h for 7 days by the clarity of solution. After this period, the implants were disassembled for confirmation of bacterial viability. Results: All the specimens with 0.7 µL and one sample of S5 presented turbidity in the control test indicating external contamination, and were excluded from the study. After 7 days of observation, none of the specimens presented positive results for microleakage and the bacterial viability was confirmed in all specimens. The 0.1 µL and 0.3 µL volumes did not present bacterial microleakage, meaning that these volumes may be inadequate for analysis. Conclusions: None of the sets evaluated showed bacterial microleakage at the I-A interface and the volume of 0.7 µL exceeded the internal capacity of the implants.

Overview of Nanoparticle Coating of Dental Implants for Enhanced Osseointegration and Antimicrobial Purposes

“…Frequent failures in dental implants therapy are related to lack of stability or misfit at the implantabutment interface (5). Indeed, micro-gap on the interface of two-piece implants with variable fluid flow at this interface (6,7) leads to the occurrence of bacterial infiltration and inflammatory cells that result in bone loss around this area (8).…”

“…Such complication leads to studies on reduction of bacterial penetration by increasing the accuracy and stability of the jointed pieces through fabricating very high precision mechanical parts. Internal conical joints have superior mechanical stability of the I-A interface and have revealed no crest bone loss (5,16). This has been explained by the stress distribution of the implant's long axis through function.…”

“…This has been explained by the stress distribution of the implant's long axis through function. The greater stability of the soft tissues provided by the tapered abutment design and its reduced diameter compared with the platform, as well as lack of abutment micromobility by the self-locking feature reduces bacterial leakage at the interface or even prevents it (5,17). However, in vitro bacterial studies at the I-A interface of the implants have attempted to evaluate the actual benefit of mechanical locking of these joints; however, variable results have been obtained in this regard.…”

Morse taper internal connection implants: would abutment reseating influence retention?

“…As a result, surface oxide layers break down, a phenomenon known as cold welding 11 . Therefore, there is less risk of gaps between the implant and abutment, producing a seal proven to delay or even prevent bacterial invasion [12][13][14] and to be clinically reliable 15 . A recent study on implant components stability demonstrated that loosening in sets with internal tapered connections is less frequent than in sets with other connection types 16 .…”