## 4 Discussion
Given its limited daily wear time, integrating electronic reminders is not a practical or effective strategy for this specific type of aligner. In the present study, the data demonstrated a consistent and statistically significant correlation between aligner wear duration and RGB value reduction, reflecting a progressive loss of whiteness. This decline was directly proportional to the level of discoloration: as RGB values decreased, the material assumed a more yellowish hue. Specifically, aligners worn for 12 h per day exhibited significantly greater reductions in RGB values compared to those worn for 7 h per day (\(p<0.001\)). These findings allow us to reject the null hypothesis, which posited no difference in discoloration between the two protocols. However, variables such as differences in salivary flow or composition, pH levels, and dietary habits may alter the chemical reactions involved in the thermos-oxidative degradation of polyamide, potentially affecting the outcomes of colorimetric assessments. [30; 31]. Parallel findings from other materials research support our observations: [PERSON] et al. investigated the color stability of polyamide-12, a material used in dental prosthetics after immersion in staining agents such as coffee and red wine [32]. The authors employed the CIE \(L\)**\(\ast\)**\(\ast\)**\(\ast\)** chromaticity system and their findings confirmed that exposure to pigmented substances significantly affected the chromatic stability of polyamide. Although not directly focused on patient compliance, their study highlights the relevance of color changes as an indicator of material aging and external exposure. Importantly, their results also suggest that factors such as oral hygiene and patient behavior may play substantial roles in the extent of discoloration. The results of the present study underscore the potential of colorimetric evaluations as a diagnostic tool for patient compliance monitoring. Future directions should include the refinement and standardization of chromatic indicators as adjunctive tools in aligner therapy. With continued development, this approach may enable more precise, real-time, and non-invasive monitoring. Furthermore, the use of mobile applications instead of more advanced equipment, such as spectrophotometers or colorimeters, would make this tool more accessible and user-friendly for clinicians. Indeed, integrating RGB-based data collection with remote health platforms or mobile applications could allow clinicians to track aligner use remotely, reducing the need for frequent in-office visits and enabling timely intervention when non-compliance is detected. Another promising avenue for future research could be the investigation of changes in material porosity and surface roughness following intraoral use. Surface characteristics such as increased roughness may potentially influence the extent of discoloration by facilitating the retention of staining agents or altering light reflection. These changes could serve as confounding variables in the interpretation of colorimetric data. Nonetheless, in the case of polyamide aligners, the discoloration observed in this study appears to be primarily driven by thermo-oxidative degradation, as evidenced by the consistent and homogeneous patterns of color change observed under controlled cleaning protocols [23,25]. Additionally, it is important to note that the NOXI Aligner is designed for 10-12 h of wear per day, primarily during the night. This limited wear time results in significantly less exposure to staining agents, cigarette smoke, and contact with oral fluids, reducing this exposure by almost 50% compared to aligners worn for 22 h a day. Further studies employing advanced characterization techniques such as scanning electron microscopy (SEM) or surface profilometry could elucidate the relationship between surface morphology and chromatic stability, thereby providing a more comprehensive understanding of material aging mechanisms in the oral environment.