## 3 Results
### Evaluation of the Surface Chemical Composition  
With regard to the samples in question, the XPS analysis provided the spectra as images. Table 3 reports the surface chemical composition obtained from the spectra themselves.  
The data obtained can be commented as follows:  
* With regards to classic systems (Syra, Prama, and Shard), the measured composition is very satisfactory and confirms the SEM-backscattered data which suggests a significant degree of surface cleaning.
* The anodized collar of Prama has a high phosphorus value: this is expected as the anodizing process often takes place in solutions that contain phosphates, it known that phosphorus is incorporated in the oxide layer formed following the anodizing process.
* The surface composition of 3i T3 confirms and explores what had already emerged from the EDX analysis and what was claimed by the manufacturer. In addition to the topographical  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Sample** & **O** & **Ti** & **N** & **Ca** & **C** & **P** & **S** & **Si** & **Zr** & **Y** & **Al** \\ \hline Syra & 52.4 & 18.4 & 1 & - & 28.2 & - & - & - & - & - & - \\ Prama & 51 & 18.7 & 1.2 & - & 28 & - & 0.4 & 0.7 & - & - & - \\ Prama—Collar & 50.4 & 14.7 & 1.2 & - & 26.2 & 6.6 & - & 0.8 & - & - & - \\
3i T3—Apical & 40.3 & 5.4 & - & 7.9 & 37 & 9.4 & - & - & - & - & - \\
3i T3—Central & 42.1 & 7.5 & - & 7.3 & 34.2 & 8.9 & - & - & - & - & - \\
3i T3—Coronal & 38.3 & 5.3 & - & 5.8 & 40.2 & 6.4 & - & 4 & - & - & - \\ Shard & 53.4 & 19.6 & 1.7 & - & 25.3 & - & - & - & - & - & - \\ NobelPearl & 51.2 & - & - & - & 22.2 & - & - & - & 16.9 & 0.9 & 8.8 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Surface composition (atomic%) of the analyzed samples.  
Figure 7: SEM images of the NobelPearl implant. Low magnification images in backscattered mode of the implant apex (**a**) 53\(\times\) and of the implant collar (**b**) 53\(\times\) show a very clean surface. All the following images are obtained by conventional methods (secondary electrons): (**c**) 200\(\times\) area of passage between the roughened part of the implant body and the collar; (**d**) 15K\(\times\) the collar area at greater magnification; (**e**) 2.5K\(\times\) topography of the surface of the implant body; (**f**) 10K\(\times\) particular of the implant body at higher magnification.  
modification, this implant surface also has a chemical modification, highlighted by the high signal of calcium and phosphorus due to the nanocrystals deposited by DCD. Even the surface of 3i T3 appears substantially free from organic contamination, although the carbon signal is a bit higher than Syra, Prama, and Shard. This data had already emerged from the SEM analysis, highlighting a greater presence of black points on the implant surface. Note that the coronal area is subjected to double acid treatment only and has a rather high silicon signal that is not registered in other areas. It could be due to masking residue likely used in the treatment phase to protect its specific area during sandblasting. The SEM-backscattered images also showed more critical issues in this area, albeit in a largely satisfactory context. The chemical composition of the NobelPearl surface presents the expected elements and is also very clean. In this case, it was not possible to perform the comparison analysis between the roughened area and the collar because, as mentioned, a non-monochromatic source was used to reduce positioning problems. In this case, the size of the analyzed area is a few millimeters and the data must be considered as an \"average\" of the different areas. In general, therefore, the results are positive for all of the implants analyzed and indicate good care in the production processes, in the final cleaning, and in the packaging phases.