Please activate JavaScript!
Please install Adobe Flash Player, click here for download

Journal of Oral Science & Rehabilitation No. 2, 2017

P l a s m a e f f e c t o n a b u t m e n t s A very important area of research is the devel- opment of efficient high-vacuum technologies able to clean and functionalize surfaces to re- place conventional methods of cleaning metal- lic or polymeric surfaces. In this context, cold plasma technology represents an efficient alter- native and has been the subject of increasing attention. Low-temperature plasma equipment works within a vacuum chamber in which atmospher- ic gases have been evacuated typically below 0.1 torr. This low pressure allows for a relative- ly long free path of accelerated electrons and ions. Since the ions and neutral particles are at or near ambient temperatures and the elec- trons, which are at high-temperature or elec- tronvolt levels, have relatively few collisions with molecules at this pressure, the reaction remains at low temperature.With appropriate plasma parameters, argon plasma removes all chemical traces of previous treatments, in effect producing cleaner and better controlled surfaces than with conventional preparation methods.23 Furthermore, the advantages of plasma cleaning can be exploited to enhance the soft- tissue response during the prosthetic implant phase. Change in the surface wettability of com- mercial pure titanium, in fact, might determine the functional response of fibroblasts and is therefore a critical factor for the adhesion of soft tissue to the titanium abutment. In the present study, no differences were found between the test and control groups for the first time point (one month of healing). How- ever, at the second time point (two months), despite the absence of statistically significant differences, a trend showing slightly better mar- ginal bone levels in the test group, compared with the control group, was observed. This may explain why a previously published study showed statistically significantly better radio- graphic bone level maintenance in humans after two- and five-year follow-up at the treated sites.24 This may suggest that, in a longer follow- up, statistical significance could also be reached in experimental studies. Although a recently published in vitro study presented no quantitative differences in terms of cell adhesion between plasma-cleaned or only sterilized titanium disks after 8 h, the same study reported qualitative differences in terms of cell spreading.25 This may suggest that a shorter analysis time frame may only show dif- ferences at the microscopical level. It can be speculated that the differences in terms of IS–B, IS–C and PM–C between the test and control groups, although they did not reach sig- nificant levels, could be the early expression of better organization of periimplant soft tissue due to a more “proactive” abutment. This speculation could be supported by the dissimilar outcomes reported by two studies with different time points. In fact, while Canullo et al. reported an absence of histological differences after one week,26 Garcia et al. observed significantly better outcomes after two weeks in terms of connective cell adhesion and soft-tissue arrange ment around abutments cleaned by plasma compared with sterile abutments.27 For this reason, the outcomes of the present investigation should be taken with caution owing to the short follow-up that may have failed to disclose differences. Conclusion Within the limitations of the present study, al- though differences between the test and control groups failed to reach significance, a trend of better marginal bone levels was found at the test sites compared with the control sites. This might suggest that the use of argon plasma might improve the soft-tissue integration of ti- tanium abutments. Acknowledgments The authors wish to express their appreciation of the skills and commitment of Dr. Audrenn Gautier in the supervision of the study. Special thanks are given to Mr. Sebastião Bianco (Uni- versity of São Paulo, Ribeirão Preto, Brazil) for his practical support. This study was supported by a grant (number 2014/04371-6) from the São Paulo Research Foundation; nevertheless, the authors designed and executed the statistical analysis and man- uscript preparation independently, and they have sole responsibility for the writing and con- tent of this article. Competing interests The authors declare that they have no compet- ing interests. 14 Volume 3 | Issue 2/2017 Journal of Oral Science & Rehabilitation

Pages Overview