Effect of Immersion in 0.12% Chlorhexidine Solution on Corrosion and Unloading Force of Rhodium Coated NiTi Archwires The types of orthodontic archwires commonly used in orthodontic treatment are NiTi non-coated and rhodium-coated. Corrosivity and unloading force on the wires may undergo changes due to the use of mouthwash, specifically chlorhexidine 0.12%. The aim of this study was to investigate the effect of immersing NiTi non-coated and rhodium-coated with a diameter of 0.014” in chlorhexidine 0.12% solution on their corrosivity and unloading force after immersion for 1, 7, and 14 days. A total of 48 NiTi non-coated and rhodium-coated archwires were divided into 12 groups (n = 4 each) cut to a length of 30 mm. They were grouped based on immersion media (chlorhexidine 0.12% and artificial saliva) and immersion time (1, 7, 14 days). In the chlorhexidine immersion group, the wires were immersed and shaken for one minute twice a day, then rinsed and immersed in artificial saliva. Samples were tested using atomic absorption spectrophotometry (AAS) and a three-point bending test. Statistical analysis was performed using two-way ANOVA, DMRT 5%, and linear regression. The NiTi non-coated archwires immersed in chlorhexidine exhibited high corrosivity of 0.0083 ppm and unloading force of 2.0275 N after 14 days. SEM analysis of NiTi non-coated archwires revealed a rougher surface with larger porosities, while rhodium-coated archwires showed peeling of the coating and pitting. The immersion of non-coated NiTi archwire and rhodium-coated archwire in chlorhexidine solution on the 14th day has the highest corrosivity and unloading force compared to immersion durations on days 1 and 7.

ABSTRACT The goal of this study was to investigate differences in alkaline phosphatase (ALP) levels in young and old rabbits after administering the soybean isoflavone genistein during orthodontic tooth movement. Twelve rabbits were used and assigned to four groups (n = 3); OG (old rabbits), OGS (old rabbits + soybean), YG (young rabbits), and YGS (young rabbits + soybean). The rabbit mandibulary incisors were distalised using a nickel-titanium open coil spring (50 g force). Genistein was administered from the initial orthodontic force delivery until day 21, at a dose of 1.2 mg/kg BW once a day. ALP levels (U/mg) were measured on days 1, 7, 14, 21 after orthodontic force delivery using a UV-Vis 6300 spectrophotometer at a 405 nm wavelength. The results were analysed by one-way analysis of variance followed by Tukey’s Honest Significant Difference (HSD) test (p < 0.05). The ALP levels between the young and old age groups were significantly different. ALP levels were highest in the YGS group, and significantly lowest in the OG group (p < 0.05). Moreover, the ALP level of the OGS group was significantly higher than that in the OG group (p < 0.05). In conclusion, daily consumption of soybean isoflavone genistein could enhance ALP levels during orthodontic tooth movement, particularly in older rabbits.
Alkaline Phosphatase ; Tooth Movement Techniques ; Rabbits