The Effect of Dehydration on Tooth Color: A Prospective In Vivo Study

Abstract

Introduction The influence of dehydration on tooth shade constitutes a significant aspect, making it a pivotal area of study, particularly within the field of restorative dentistry. This prospective study was done to analyze, using a spectrophotometer, how dehydration affects the shade of the teeth. Materials and methods Twenty-five participants were recruited in this prospective study that took place in the Dental Care Center of Saint Joseph University of Beirut (Lebanon) between October 2022 and January 2023. The inclusion criteria for this study primarily comprised four intact maxillary incisors. On the other hand, damage, cavities, restorations, and staining served as exclusion criteria. The VITA Easyshade Advance (Vident, Brea, CA) spectrophotometer was used to record the measurements. The measures of L (which represents darkness to lightness), a (which represents greenness to redness), and b (which represents blueness to yellowness) were registered at the center of each tooth's labial surface at baseline and then at 10-minute intervals for 30 minutes while the teeth were dehydrating due to the placement of a rubber dam. The color difference (ΔE) was later calculated using L*a*b* measures, with the perceptibility threshold set at ΔE00=0.8. Statistical analyses were performed using the Friedman test, the Bonferroni post hoc test, and the Wilcoxon signed-rank test. Results The different color changes represented by ΔE (ΔE1, ΔE2, and ΔE3) were found to be significantly higher than the perceptibility threshold of 0.8 (p<0.001). A statistically significant difference was found between ΔE1 and ΔE3 (p<0.05). Moreover, a statistically significant difference was found between L0, L10, L20, and L30 (p<0.001). Statistically significant differences (p<0.05) exist between the means of L0 and L20, the means of L0 and L30, the means of L10 and L20, and the means of L10 and L30. Conclusion This study showed that dehydration affected the shade of the teeth: Lightness increased, and therefore, the teeth appeared whiter. Dentists should consider the hydration status of the teeth when evaluating color for treatments, as dehydration can significantly affect shade matching: the more the dehydration time elapses, the more the color difference compared to the baseline increases.

In‐vivo evaluation of the effects of short‐term dehydration and rehydration on the color differences of immature permanent incisor teeth

“…Methodological differences create challenges in directly comparing the results of the study with other research. Participant numbers in the studies, their presence in different age groups, color measurements from different teeth, the use of different color measurement devices, and the limited number of in‐vivo studies are among the other variations in this study 9–17 …”

“…There are two primary methods to assess tooth color clinically: subjective visual determination using tooth shade guides and employing spectrometers. Spectrophotometers, spectroradiometers, and colorimeters are instruments used in such measurements 9–17 . Visual color selection using a guide is a quick and cost‐effective method, but it is considered inconsistent and subjective.…”

“…In light of this information, it has been anticipated that enamel/dentin dehydration might differ based on the changes in blood circulation within the tooth (pulp). In the literature, color changes in teeth with completed root development after dehydration, and their rehydration processes have been evaluated based on different parameters 9–16 . As far as we know, there is no research on how the dehydration‐rehydration process progresses at different root development stages of teeth with open apices, how the optical properties of the tooth crown change, and how they compare with teeth with closed apices.…”

“…Spectrophotometers, spectroradiometers, and colorimeters are instruments used in such measurements. [9][10][11][12][13][14][15][16][17] Visual color selection using a guide is a quick and cost-effective method, but it is considered inconsistent and subjective. Many factors, such as proper lighting, color acuity, and eye fatigue, can affect this color selection method.…”

“…In the literature, color changes in teeth with completed root development after dehydration, and their rehydration processes have been evaluated based on different parameters. [9][10][11][12][13][14][15][16] As far as we know, there is no research on how the dehydration-rehydration process progresses at different root development stages of teeth with open apices, how the optical properties of the tooth crown change, and how they compare with teeth with closed apices. This study's objective is to determine how root apex opening levels impact color parameters during dehydration and rehydration processes in immature permanent upper incisor teeth with different level unclosed apices.…”