A atorvastatina e o alendronato interferem na movimentação dentária induzida em ratos via redução das atividades inflamatória e reabsortiva e aumento de anabolismo ósseo

Abstract

The induced tooth movement (MDI) depends on inflammatory and bone remodeling processes in sites of compression and traction. During orthodontic treatment, drugs can modulate the movement´s rate. In this context, we investigated the influence of atorvastatin (ATV), alendronate (ALD), or combination of these drugs (ATV+ALD) on MDI in rats. First, groups of animals (n=6/group) were euthanized at the 6th hour, and on the 1st, 4st, 7st, 11st, 14st and 21st days, and they had their hemimaxillas analyzed for the distance between molars and incisors, histomorphometry of periodontal ligament (PL) of distobuccal, intermediate and distolingual roots, and myeloperoxidase activity (MPO; x 103 U/mg of tissue). For pharmacological approach, the animals received by gavage during 28 d distilled water (H2Od, 2 ml/kg/d), ATV (1, 3 and 9 mg/kg/d), ALD (1 and 7 mg/kg/wk), or the combination of lower doses of these drugs (ATV+ALD). Then, the rats were submitted to MDI 11 days prior to euthanasia. The distance between molars and incisors, histomorphometry, MPO, IL-1β levels (pg/mg of tissue), immunostaining for RANKL, OPG and TRAP, and serum levels of bone alkaline phosphatase (BALP; U/l) were evaluated. This study was approved by the Ethical aspects: Ethics Committee on Animal Research-UFC No. 21/14. The time course showed a reduction of the distance between molars and incisor, becoming significant from the 11th day, when compared to the 1st day. In the compression side, there was significant reduction in the PL and increased hyaline areas and traction areas in the 6th hour and on the 1st and 4th days. The LP returned to normal on the 7th day and the hyaline areas disappeared after the 14th day. MPO peaked between 6th hour and 1th days. Untreated animals showed decreased the distance between molars and incisors and had severe bone and root resorption, formation of hyaline areas in LP, an increase of MPO and IL-1β levels, greater immunostaining RANKL and TRAP, and lower for OPG, and reducing BALP on the 11th days post MDI. ATV, ATV+ALD and ALD reduced MDI, and the highest doses prevented it. The treatments did not alter histomorphometry LP (p>0.05) and caused greater bone and root preservation. ATV, ATV+ALD and ALD7 reduced the hyaline areas (p<0.05) vs H2Od. ATV9 reduced MPO activity and IL-1β levels (p<0.05) vs H2Od. ALD1 and ATV+ALD reduced the levels of IL-1β (p<0.05) vs H2Od. All doses of the treatments reduced immunostaining for RANKL and TRAP, and increased the immunostaining for OPG. Furthermore, ATV, ALD and ATV+ALD reduced the BALP, when compared to non-treated animals. However, ATV3 and 9, ALD1 and ATV+ALD increased BALP vs H2Od, while ALD7 protected this reduction. In conclusion, ATV and ALD showed anti-inflammatory and antiresorptive effects by reducing MPO levels and/or IL-1β, immunostaining for RANKL and TRAP, and interfere in the bone anabolism, by increasing OPG immunostaining and serum BALP.