## 4 Discussion
The equipment in the clinical context was sensitive to the patient's movement, contaminations, various tooth shapes, different angles, and the location of the probe. In addition, the integrated light source's efficiency may alter with time, changing the observed results. On the other hand, the values of L, a, and b were standard for each device and could not be used with both devices for examinations. This suggests that both the dental lab and the dentist must communicate to use the same devices [52]. Due to the scanning procedure and basic design of intraoral scanners, which are supported by a high-definition camera and LEDs, the outer source of light may have less effect on them [32; 53]. In previous research, [PERSON] et al. proved that the repeatability of the 3 Shape Trios (86.66%) had a higher level than the visual matching (75.22%) [51]. On the other hand, [PERSON] et al. carried out an in vivo study that used a Spectroshade for tooth color measurement and found the spectrophotometer to be a better referent device than an intraoral scanner and digital single lens reflex camera. The study used a spectrophotometer and a DSLR camera, which produced similar results, and an intraoral scanner produced different results [20]. Based on the results found in the present study, measurements with a spectrophotometer and the Vita classical shade guide are close to each other. On the other hand, results obtained with an intraoral scanner (3 Shape Trios) had different results. There is limited literature that compares the results of different color analysis methods. The results for the color assessment using different measuring techniques varied, as demonstrated by [PERSON] et al., who evaluated color stability using the Vita classical shade guide with a spectrophotometer [54]. The spectrophotometer device produced less accurate findings than the visual technique, although the spectrophotometer displayed far higher interrater agreement values. Nevertheless, the authors stated that to achieve an effective and reliable result, it is necessary to carefully combine both methods. One limitation was that the spectrophotometer's performance was below expectations and that during specimen measurement, the device overheated. [PERSON] et al. used a spectrophotometer to demonstrate the color stability of composite resin, although the findings of the study were limited because no finishing or polishing procedures were applied to the specimen's surfaces [23]. [PERSON] et al. demonstrated stability in tooth color selection between 3 Shape Trios with the visual methods and found that the first one provided more repeatability in the tooth coloration matching process than visual techniques. The small specimen size of 10 patients and minimal experience of the study by [PERSON] et al., since the measurements were made by students, are other limitations [55]. Despite previous publications, color stability still concerns dentists and patients. Recently, [PERSON] et al. used a spectrophotometer to evaluate the color stability of nanohybrid and microhybrid composites after immersion in tea and Coke drinks. They found that microhybrid composite had more color stability than nanohybrid composite, and tea caused more discoloration of resins [35]. Some limitations of this study must be considered since these results are only applicable to resin composites that are 2 mm thick. Therefore, it is uncertain what the outcome would be for specimens that are larger. Another limitation is that the specimens were not aged by thermocycling. Furthermore, it is important to note that further research is warranted, particularly in the form of clinical trials.