Chemical and Topographic Analysis of Eight commercially Available Dental Implants

Surface bio-functionalization using plasma of argon could alter microbiological and topographic surface analysis of dental implants?

BACKGROUND

Plasma of argon was demonstrated to improve protein and cell adhesion on implant surface. On the other hand, increased surface energy and hydrophilicity could potentially amplify the risks of implant surface contamination during clinical phases, risks that have not yet been evaluated in Literature. The aim of the present in vitro study was to verify if Plasma treatment could alter the implant surface characteristics and its ability to remain sterile.

MATERIALS AND METHODS

Implants from 9 brands were collected (n=11). One implant for each company was used for SEM surface analysis. To perform the microbiological analysis, ten implants from each company were used and randomly split by allocation either in test or control group. To replicate the surgical work flow, both test and control samples were left 60s in clinical environment. Bacterial growth analysis was performed. Optical density at 600nm was measured as readout of bacterial growth and colony forming unit (CFU) after 24h was evaluated. Statistical analysis was performed by using the Wilcoxon Mann Whitney test. A p-value lower than 0.05 was considered significant.

RESULTS

SEM analysis revealed different categories of implant surface roughness. The optical density confirmed a readout of bacterial growth between 4 and 7 with no significant differences within groups. The number of CFU/ml for each measured sample (test and control) was lower than 102 and failed to present significant differences.

CONCLUSION

Surface activation using plasma of argon did not affect the degree of implant contamination, allowing to maintain a substantial sterility of the implant independently of its morphology. This may allow in the next future the use of bioactivation through plasma of argon to exploit the superhydrophilicity deriving from this biophysical process.

Changes in surface characteristics of titanium and zirconia after surface treatment with ultraviolet light or non-thermal plasma

Positive effects of irradiation with ultraviolet (UV) light or treatment with non-thermal plasma on titanium and zirconia surfaces have been described in various studies. The aim of this study was to assess and compare the changes in the physicochemical surface conditions of titanium and zirconia surfaces after a short treatment with UV light or with non-thermal plasmas of argon or oxygen. Titanium and zirconia samples with moderately rough surfaces were treated for 12 min either in a UV-light oven or in a non-thermal plasma reactor that generates non-thermal plasmas of oxygen or argon. Changes in surface conditions were assessed by confocal microscopy, dynamic contact angle measurement, and X-ray photoelectron spectroscopy (XPS). No changes in roughness occurred. Ultraviolet irradiation and non-thermal plasma significantly increased the wettability of the titanium and zirconia surfaces. X-ray photoelectron spectroscopy showed an increase of oxygen and a significant decrease of carbon after treatment with either method. Thus, ultraviolet light and non-thermal plasma were found to be able to improve the chemical surface conditions of titanium and zirconia following a short exposure time. However, further in vitro and in vivo studies are needed to determine the relevance of the results.

Early Bone Formation around Immediately Loaded Transitional Implants Inserted in the Human Posterior Maxilla: The Effects of Fixture Design and Surface

Aim. To evaluate the effects of fixture design and surface on the early bone formation around immediately loaded implants inserted in the human posterior maxilla. Materials and Methods. Ten totally edentulous subjects received two transitional implants: one tapered implant with knife-edge threads/nanostructured calcium-incorporated surface (test: Anyridge®, Megagen, Gyeongbuk, South Korea) and one cylindrical implant with self-tapping threads/sandblasted surface (control: EZPlus®, Megagen). The implants were placed according to a split-mouth design and immediately loaded to support an interim complete denture; after 8 weeks, they were removed for histologic/histomorphometric analysis. The bone-to-implant contact (BIC%) and the bone density (BD%) were calculated. The Wilcoxon test was used to evaluate the differences. Results. With test implants, a mean BIC% and BD% of 35.9 (±9.1) and 31.8 (±7.5) were found. With control implants, a mean BIC% and BD% of 29.9 (±7.6) and 32.5 (±3.9) were found. The mean BIC% was higher with test implants, but this difference was not significant (p = 0.16). Similar BD% were found in the two groups (p = 0.9). Conclusions. In the posterior maxilla, under immediate loading conditions, implants with a knife-edge thread design/nanostructured calcium-incorporated surface seem to increase the peri-implant endosseous healing properties, when compared to implants with self-tapping thread design/sandblasted surface.