## 4 Discussion
Several reports concluded that silane treatment, in a separate stage and prior to the application of a universal adhesive, significantly improved bond strength [10; 42; 43; 44; 45; 46]. Regarding the content of silane within the composition of universal adhesives, the literature indicated that it is not of importance, and results showed the same bond strength and quality between silane and silane-free adhesives [44; 45; 46]. As far as it concerns the intention of the acid-etching stage, [PERSON] et al. [47] claimed that the sole application of Monobond Etch & Prime provides comparable SBS values to those with a separate HF-acid-etching stage, while [PERSON] et al. [48] argued that the exclusion of the acid-treatment stage before silane application results in lower \(\mu\)-SBS values. In the positive control group F, all tested materials and surface treatments were sequentially implemented in a logical order. As expected, this resulted in the highest SBS values measured in this study. It could be assumed that any potential voids or imperfections in the silane monolayer formation on the ceramic surface left by Monobond Etch & Prime are filled or repaired by the application of pure silane solutions, such as Monobond Plus, and the possible addition of silane-containing universal adhesives. This way, the multiple silanization stages may complement each other, enhancing bonding. In this study, the influence of two recently introduced materials from the same manufacturer, Ivoclean and Monobond Etch & Prime, was evaluated in an in-vitro experimental environment. Ivoclean is meant to be applied on the ceramic surface after the try-in of the restoration and contamination by saliva. Most relevant published work focused on contaminated ceramic surfaces to evaluate the decontamination potential of the material [19; 21; 29; 34]. In this experiment, the research question was whether there was any influence, either positive or negative, on bond strength of possible surface modification or Ivoclean remnants that was not linked to cleaning ability or residual contaminants. The findings of the study did not indicate any positive or negative effect on SBS values of Ivoclean treatment. Demonstrating a potential negative influence on bond strength would raise skepticism regarding its use in clinical conditions. In such cases, the cumulative result should be taken into consideration. Hence, it could be assumed that the results of the current study are in agreement with those studies that demonstrated a positive influence of Ivoclean on SBS after contamination. For Monobond Etch & Prime, the main outcome arising from these results was that it significantly improved bond strength, even if used in a single-step treatment on the ceramic surface. The present study, like all in vitro studies, has its limitations. In this context, to draw conclusions applicable to clinical scenarios, clinical trials and retrospective studies are necessary. The absence of contaminants in this experiment provides a repeatable experimental protocol with reliable results; however, it overlooks the influence of ceramic surface contamination, a crucial factor that may affect clinical outcomes. Using a rubber dam and sandblasting prior to try-in might reduce ceramic surface contamination. Alternatively, cleaning agents seem to offer a reliable surface decontamination treatment. Another limitation of the current study is that SBS values were obtained 24 h after bonding procedures. Artificial aging in such cases may provide more information on the bond between the restorative material and the resin cement. Additionally, more restorative materials and resin cements should be investigated in future studies to enrich data on the behavior of these materials during bonding procedures.