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

ObjectiveTo discover 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.MethodsOrthodontic 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.ResultsCompared 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.ConclusionThe optimal delivery of rhsTNF-RI was local injection of 0.1 ml at 0.1 μg/ml every three days.