## 4 Discussion  
The findings of this study provide valuable insights into the effects of different air-polishing powders on the surface roughness of the 3M Filek(tm) Supreme XTE composite resin and the Fuji(tm) IX glass ionomer cement. Surface roughness is a critical factor in restorative dentistry as it influences not only the esthetic outcome but also the material's \begin{table}
\begin{tabular}{c c c} \hline
**Description** & **Difference between Means** & \(p\)**-Value** \\ \hline Erythntitol/Bicarbonate & \(-0.245\) & \(0.129\) \\ Glycine/Bicarbonate & \(-0.497\) & \(0.004\) \\ Glycine/Erythritol & \(-0.252\) & \(0.117\) \\ \hline \end{tabular}
\end{table} 
Table 6: [PERSON]’s post hoc test results. Figure 9: 3M Filek SEM images at 500 and 200 magnification. resistance to bacterial colonization and wear [10]. The results demonstrate that the type of abrasive powder and the duration of exposure have significant impacts on the surface characteristics of these dental materials. This study reveals that sodium bicarbonate consistently produces higher surface roughness values compared with erythroid and glycine, regardless of the material or exposure time. This outcome is consistent with previous research indicating that sodium bicarbonate, due to its relatively larger particle size and higher abrasiveness, tends to create a more uneven surface [17]. The increased surface roughness associated with sodium bicarbonate may be detrimental in clinical scenarios, where a smooth finish is crucial for minimizing plaque accumulation and enhancing the longevity of restorations [9]. This study's findings align with earlier research that has shown the roughening effect of sodium bicarbonate on enamel and restorative materials. [PERSON] et al. [18] note that the frequent use of sodium bicarbonate in air polishing could exacerbate surface wear, especially on materials that are less resilient to mechanical stress, such as glass ionomer cements. These findings highlight the need for caution when using sodium bicarbonate, particularly in patients with restorations made from materials that are more susceptible to surface roughening. Conversely, erythroid and glycine, both of which are characterized by finer particle sizes, result in significantly lower surface roughness. These findings align with studies that have highlighted the gentler action of these powders on dental surfaces, making them suitable for procedures where minimal surface alteration is desired [19; 20]. Glycine, in particular, shows the lowest roughness values across all groups, corroborating its use in subgingival applications where surface preservation is paramount. This suggests that glycine could be the preferred choice in situations where maintaining the integrity of the restorative surface is essential. The clinical implications of these findings are substantial. Glycine, with its minimal impact on surface roughness, is increasingly being recognized as a safe and effective option for both supra- and subgingival polishing [21]. Its gentle action reduces the risk of damaging restorative surfaces while still providing effective biofilm removal. This balance between efficacy and safety makes glycine particularly useful in maintenance therapies for patients with complex restorative cases, such as those involving multiple types of restorations or areas prone to wear [22]. Interestingly, the effect of exposure time is more pronounced with sodium bicarbonate than with erythroid or glycine. Specifically, extending the polishing time from 5 to 10 s leads to a substantial increase in surface roughness for sodium bicarbonate, while the changes are less significant for the other powders. This observation underscores the importance of controlling exposure time, especially when using more abrasive powders, to prevent excessive roughening of the restoration surface [23]. It also suggests that, while longer exposure times may be necessary for effective cleaning, they must be balanced against the potential for increased surface damage.