Examination of tooth discoloration during retention period in patients using different retention devices

The aim of this study is to comparatively examine the in-vivo effects of different retention devices used to prevent relaps after orthodontic treatment on tooth discoloration. A total of 120 teeth, including maxillary central, lateral and canine teeth, of 60 individuals who had completed orthodontic treatment in Bolu Abant University Faculty of Dentistry Department of Orthodontics were included in the study. Individuals were divided into 3 groups of 20 as those using a lingual retainer and vacuum-formed thermoplastic clear plaque, using only vacuum-formed thermoplastic clear plaque, and using Hawley appliance. Vita EasyShade Advance (Vita Zahnfabrik, H. Rauter GmbH&Co, Germany) was used to evaluate color changes in teeth. Measurements were made from the middle third of the buccal surfaces of the teeth on the day of removal of the brackets after fixed orthodontic treatment and in the 1st, 3rd, and 6th months of the retention phase. To determine the tooth color, the Commission Internationale de l'Echairage L* a* b* system, which expresses the color coordinates with the symbols L*, a* and b*, was used and the ΔE values between the time periods were calculated. The Friedman Halton test was used to compare the changes over time, and the Wilcoxon Signed Rank test was used to determine the measurement differences between values. Kruskal Wallis test was used for group measurements of 3 and above, and Mann Whitney U test was used to determine the differences in groups. Significance was evaluated at p<0.01 and p<0.05 levels. The color changes (ΔE) of all tooth types measured in the three groups were found to be 1.53 to 1.82 ΔE units in Group 1, 1.33 to 1.81 ΔE units in Group 2, and 1 in Group 3 after orthodontic treatment. It was determined that between .38 and 1.95 ΔE units and clinically acceptable visible color change occurred. KEYWORDS: Retention Period, Color Change, Hawley, Essix, Lingual Retainer.