OBJECTIVETo compare the effects of pamidronate and ibandronate on orthodontic root resorption.

METHODSSeventy-two 6-week-old female specific pathogen free (SPF) Wistar rats were selected to establish models for orthodontic tooth movement. The rats were randomly divided into three groups: the control group (C group), pamidronate group (Pm group) and ibandronate group (Ib group). 0.9% normal saline,0.5 mmol/L pamidronate and 0.5 mmol/L ibandronate were injected every 3 days. The rats were executed in batch on the 3rd, 7th and 14th day to make tissue sections. All statistical analysis was performed using the PASW Statistics 18 software package.

RESULTSOn the 7th and 14th day, the amount of cementoclast, the expression of osteoclast differentiation factor (ODF) and root resorption index were significantly lower in Pm group [the 7th day: (2.675 ± 0.002), (0.1683 ± 0.0007), (0.103 ± 0.003); the 14th day: (3.886 ± 0.048), (0.1873 ± 0.0014), (0.283 ± 0.001)] and Ib groups[the 7th day: (2.601 ± 0.001), (0.1634 ± 0.0010), (0.099 ± 0.002); the 14th day: (3.754 ± 0.019), (0.1818 ± 0.0016), (0.281 ± 0.001)] than in C group[the 7th day: (2.810 ± 0.001), (0.1792 ± 0.0008), (0.120 ± 0.001); the 14th day: (4.800 ± 0.001), (0.2060 ± 0.0007), (0.401 ± 0.001)] (P < 0.05). However, no significant difference was found between Pm and Ib groups on the 3rd, 7th and 14th day (P > 0.05).

CONCLUSIONSBoth pamidronate and ibandronate could inhibit orthodontic root resorption.