Influence of dose, dose interval and administration route of recombinant human soluble tumour necrosis factor receptor type I on orthodontic tooth movement in rats

Objective cover the optimal dose, dose interval, and more advantageous administration route of recombinant human soluble tumour necrosis factor receptor type I (rhsTNF-RI) on orthodontic tooth movement. s ontic tooth movement (OTM) models were established in Sprague-Dawley rats. The maxillary left first molars were given local injections of phosphate-buffered saline (PBS) and four different concentrations of rhsTNF-RI. On day 14, the amount of tooth movement was registered, and tissue sections were stained with haematoxylin–eosin and tartrate-resistant acid phosphatase. After obtaining the optimal dose, the same models were used to investigate the optimal dose interval and more advantageous route of administration. s ed with the control group, the amount of OTM and the number of TRAP-positive cells in the 0.04 μg/ml group showed no significant changes, whilst were greatly reduced in the other three groups. In the experiment of finding the optimal dose interval, no significant differences were observed in every-two-day and every-three-day injection groups compared to the control. However, every-four-day injection group showed significant difference in the amount of OTM and histological changes. There was no significant difference between local and systemic application of rhsTNF-RI. sion timal delivery of rhsTNF-RI was local injection of 0.1 ml at 0.1 μg/ml every three days.