title: Physical properties of root cementum: part 20. Effect of fluoride on orthodontically induced root resorption with light and heavy orthodontic forces for 4 weeks: a microcomputed tomography study.
abstract: BACKGROUND
  The major side effect of orthodontic treatment is orthodontically induced inflammatory root resorption. Fluoride was previously shown to reduce the volume of the root resorption craters in rats. However, the effect of fluoride on orthodontically induced inflammatory root resorption in humans has not yet been investigated. The aim of this study was to investigate the effect of high and low amounts of fluoride intake from birth on orthodontically induced inflammatory root resorption under light (25 g) and heavy (225 g) force applications.
  
  
  METHODS
  Forty-eight patients who required maxillary premolar extractions as part of their orthodontic treatment were selected from 2 cities in Turkey with high and low fluoride concentrations in the public water of ≥ 2 and ≤ 0.05 ppm, respectively. The patients were randomly separated into 4 groups of 12 each: group 1, high fluoride intake and heavy force; group 2, low fluoride intake and heavy force; group 3, high fluoride intake and light force; and group 4, low fluoride intake and light force. Light or heavy buccal tipping orthodontic forces were applied on the maxillary first premolars for 28 days. At day 28, the teeth were extracted, and the samples were analyzed with microcomputed tomography.
  
  
  RESULTS
  Fluoride reduced the volume of root resorption craters in all groups; however, this effect was significantly different with high force application (P = 0.015). It was also found that light forces caused less root resorption than heavy forces. There was no statistical difference in the amount of root resorption observed on root surfaces (buccal, lingual, mesial, and distal) in all groups. However, the middle third of the roots showed the least root resorption. With high fluoride intake and heavy force application, less root resorption was found in all root surfaces and root thirds.
  
  
  CONCLUSIONS
  Fluoride may reduce the volume of root resorption craters. This effect is significant with heavy force applications (P <0.05). The cervical and apical thirds of the root showed significantly greater root resorption after the application of buccal tipping force for 4 weeks.
authors: Department of Orthodontics, University of Sydney, Sydney, Australia.
authors: Ersan Ilsay
authors: EI
authors: Karadeniz
authors: Carmen
authors: C
authors: Gonzales
authors: Oyku
authors: O
authors: Nebioglu-Dalci
authors: Dennis
authors: D
authors: Dwarte
authors: Tamer
authors: T
authors: Turk
authors: Devrim
authors: D
authors: Isci
authors: Aynur M
authors: AM
authors: Sahin-Saglam
authors: Huseyin
authors: H
authors: Alkis
authors: Selma
authors: S
authors: Elekdag-Turk
authors: M Ali
authors: MA
authors: Darendeliler
mesh_terms: D000293:Adolescent; D000497:Alloys / Q000737:chemistry; D001641:Bicuspid / Q000601:surgery; D001696:Biomechanical Phenomena; D002327:Cariostatic Agents / Q000008:administration & dosage*; D002648:Child; D003722:Dental Alloys / Q000737:chemistry; D003739:Dental Cementum / Q000187:drug effects* / Q000473:pathology; D005260:Female; D005457:Fluoridation; D005459:Fluorides / Q000008:administration & dosage*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D012391:Root Resorption / Q000209:etiology* / Q000473:pathology / Q000517:prevention & control; D012690:Serial Extraction; D013314:Stress, Mechanical; D013997:Time Factors; D019227:Tooth Apex / Q000187:drug effects / Q000473:pathology; D019237:Tooth Cervix / Q000187:drug effects / Q000473:pathology; D014087:Tooth Movement Techniques / Q000295:instrumentation / Q000379:methods*; D014092:Tooth Root / Q000187:drug effects* / Q000473:pathology; D055114:X-Ray Microtomography / Q000379:methods*; D055815:Young Adult
chemical_list: D000497:Alloys; D002327:Cariostatic Agents; D003722:Dental Alloys; C525450:titanium molybdenum alloy; D005459:Fluorides