Comparison Of Effect Between Ibuprofen And Chinese Herbal Medicine Duyiwei On Root Resorption Associated With Orthodontic Movement In Rats

Objective:The aim of this study was to provide referrence for the prevention and treatment of the orthodontic root resorption during clinic by comparing the effect between Ibuprofen and Duyiwei on root resorption.Methods:In this study,35 adult healthy male Wistar rats selected were randomly divided into three experimental groups:Saline group, comprised of 9 rats, saline gavage; Ibuprofen group, comprised of 13 rats, prepared Ibuprofen suspension gavage; Duyiwei group, comprised of 13 rats, prepared Duyiwei suspension gavage. After the rats were general anesthetized with 3% chloral hydrate, an initiate force of 100 grams was applied beween the right maxillary first molars and the incisors in all the animals, then the orthodontic root resorption animal model was established. All the animals were killed after two weeks. Histological examinations were performed on all the above samples. Some sections were stained with hematoxylin and eosin to observe the morphology change of the periodontium. An image analysis system was used to measure the number, length and depth of the root resorption lacunaes, tartrate-resistant acid phosphatase staining was used to quantify mature and committed clast cells, Scanning Electron Microscope examinations were used to observe the microcosmic change on the root surface. The data was analyzed with the statistics software SPSS 13.0.Result:1. Observation of periodontium on HE stained histological sectionSaline group:the periodontium on the pressure side became narrow and the fiber arranged disordered; the resorption area on the root was distinct, some areas appeared deep and broad resorption lacunaes with large area of cementum stripping, the deepest resorption area can reach the half depth of dentin; the root resorption area concentrated a large number of multi-nucleated odontoclasts; there were a large number of bone resorption lacunaes on the vicinity alveolar bone area, osteoclasts were distributed in the resorption lacunaes or along the trabecular.Ibuprofen group and Duyiwei group:the periodontium on the pressure side slightly narrowed, the fibers arranged without rule; the root resorption was light compared with Salin group, the resorption area was small and shallow, there was plum osteoblast-like matrix at the bottom of the resorption lacunaes; the surrounding alveolar bone resorption lacunas were less, neonatal line around showed the repair of the new bone; odontoclasts on the root surface and osteoclasts at adjacent alveolar bone were less than the Saline group.2. Image AnalysisImage analysis measurements showed that on the pressure side of the experimental roots:There was no statistic difference about the lacunae number among the three groups (P>0.05)There was statistic difference about average length among three groups (P<0.05) After q-test, there was statistic difference between each two groups (P<0.05)There was statistic difference about average depth among three groups (P<0.05) After q-test, there was statistic difference between Saline and Ibuprofen group or Duyiwei group (P<0.05), while not between Ibuprofen and Duyiwei group (P>0.05).There was statistic difference about length index among three groups (P<0.05) After q-text, there was statistic difference between Saline and Ibuprofen group or Duyiwei group (P<0.05), while not between Ibuprofen and Duyiwei group (P>0.05).3. TRAP staining and osteoclast counting:TRAP positive cell around the root and alveolar bone counting results showed that: There was statistic difference of the number of TRAP positive cell between Ibuprofen group and Saline group, Duyiwei group and Saline group (P<0.05). But there was no statistic difference beween Ibuprofen group and Duyiwei group (P>0.05) 4. Result of observation with Scanning electron microscopyThere were clearly root resorption lacunas among the three groups, with the Saline group most severe. The root resorption lacunas of the Saline group showed a more room-like changes with clear border. It can be seen dentinal tubules at the bottom of resorption lacuna in some severe areas, indicating resorption has been deeply up to dentin. Ibuprofen group showed that small and isolated resorption lacunas scattered on the root surface, Duyiwei group showed that small and isolated pits integrated into the larger pits, without obvious dentinal tubules at the bottom.Conclusion:1. It is succeeded to establish an animal model of orthodontic root resorption like that:using the central incisor as anchorage, an improved orthodontic appliance applying a force of 100g to draw the rats'right maxillary first molar medially, with stripping groove and gluing to reinforce retention.2. Ibuprofen and Duyiwei have an inhibitory effect on orthodontically induced root resorption.3. There is no difference of the inhibitory effect between Ibuprofen and Duyiwei on orthodontically induced root resorption.