Relationship between Roughness and Wettability of Nine Types of Implant Surfaces and Potential Interference of Surface Oxygen and Carbon: In Vitro Evaluation

Aim: To assess the roughness and hydrophilicity of nine types of dental implant surfaces, while also examining the presence of contaminants carbon and oxygen on these surfaces. Furthermore, the study investigated potential correlations between these characteristics across the analyzed surfaces. Materials and Methods: The surfaces analyzed were as follows: MI: machined (turned), Implacil implant; TOI: blasted with titanium oxide, Implacil implant; TOAEI: blasted with titanium oxide and acid-etched, Implacil implant; ZAED: blasted with zirconia and acid-etched, DSP implant; CPD: coated with calcium phosphate, DSP implant; XD: subjected to an experimental treatment (patent pending), DSP implant; DAEHAS: double acid-etched and activated with hydroxyapatite nano-crystals, SIN implant; DAES: double acid-etched, SIN implant; and AMP: untreated surface of the Plenum implant, produced by additive manufacturing. Four and five disc-shaped specimens were used in the hydrophilicity and roughness assessments, respectively. Roughness was evaluated by optical profilometry and scanning electron microscopy; hydrophilicity was determined using the sessile-drop technique; and the chemical analysis was performed using X-ray photoelectron spectroscopy. The Kruskal- Wallis, Mann-Whitney, and Spearman correlation tests were employed to analyze the data (p < 0.10). Results: Significant differences were observed among the analyzed surfaces in terms of both roughness and hydrophilicity (p < 0.001). The surface exhibiting the highest roughness was AMP, whereas the greatest hydrophilicity was exhibited by CPD. Correlations between roughness and hydrophobicity were observed for MI (r = 0.936, p = 0.009), ZAED (r = 0.957, p = 0.004), and DAES (r = 0.964, p = 0.005). The carbon concentration observed on the CPD surface was lower than that observed on the other surfaces, whereas the oxygen concentrations were similar. No correlations were observed between the presence of contaminants and the roughness or hydrophilicity characteristics. Conclusion: Roughness and hydrophilicity values exhibited considerable variation among the tested surfaces. Aside from the CPD surface, comparable concentrations of carbon and oxygen were detected. Although correlations between roughness and hydrophilicity were observed only for the ZAED, DAES, and MI surfaces, these correlations were inadequate to establish a causal relationship between the two surface characteristics.