title: Healing of the roots and surrounding structures after intentional damage with miniscrew implants.
abstract: BACKGROUND
  In this study, we evaluated the healing potential of the roots and surrounding periodontium (cementum, periodontal ligament [PDL], and bone) after intentional damage during miniscrew implant (MSI) placement.
  
  
  METHODS
  A randomized split-mouth design was used to evaluate healing 6 and 12 weeks after intentional root damage. Seven skeletally mature male beagle dogs had MSIs placed into the roots of 8 mandibular teeth (6 premolars, 2 first molars). After root contact had been verified by using insertion torques and radiographs, the MSIs were immediately removed, and the sites were allowed to heal for 6 or 12 weeks. Sequential point labeling was performed at 6-week intervals with tetracycline and calcein. Demineralized and undemineralized sections were stained, and healing was histologically evaluated.
  
  
  RESULTS
  The placement torque was twice as high with root contact than without contact (23.8 vs 50.7 Ncm). Damage to the roots and periodontium ranged from cementum interruption to pulp invasion. New bone, PDL, and cementum were observed in 64.3% of the teeth, with significant (P <0.05) increases in the percentages of cementum over time. Sequential labeling confirmed healing at both 6 and 12 weeks. Abnormal healing was found in 35.7% of teeth; it included lack of PDL and bone regeneration, bone degeneration in the furcation area, ankylosis, and no healing associated with inflammatory infiltrate or pulpal invasion.
  
  
  CONCLUSIONS
  Under favorable conditions (no inflammatory infiltrate or pulpal invasion), healing can occur when root damage caused by MSIs is limited to the cementum or the dentin. Increased resistance should be used as an indicator of possible root contact during MSI placement.
authors.affiliation: Orthodontic Department, Baylor College of Dentistry, Texas A&M Health Science Center, Dallas, TX 75246, USA.
authors.forename: Carmen E
authors.initials: CE
authors.lastname: Brisceno
authors.forename: P Emile
authors.initials: PE
authors.lastname: Rossouw
authors.forename: Roberto
authors.initials: R
authors.lastname: Carrillo
authors.forename: Robert
authors.initials: R
authors.lastname: Spears
authors.forename: Peter H
authors.initials: PH
authors.lastname: Buschang
mesh_terms: D016301:Alveolar Bone Loss / Q000209:etiology / Q000473:pathology; D000539:Alveolar Process / Q000293:injuries / Q000473:pathology; D000818:Animals; D001641:Bicuspid / Q000293:injuries; D001863:Bone Screws / Q000009:adverse effects*; D004396:Coloring Agents; D003739:Dental Cementum / Q000293:injuries / Q000473:pathology; D003782:Dental Pulp / Q000293:injuries / Q000473:pathology; D003804:Dentin / Q000293:injuries / Q000473:pathology; D004285:Dogs; D005456:Fluorescent Dyes; D017823:Furcation Defects / Q000209:etiology / Q000473:pathology; D008297:Male; D008963:Molar / Q000293:injuries; D052280:Orthodontic Anchorage Procedures / Q000009:adverse effects / Q000295:instrumentation*; D010513:Periodontal Ligament / Q000293:injuries / Q000473:pathology; D010519:Periodontium / Q000293:injuries* / Q000473:pathology; D011897:Random Allocation; D013997:Time Factors; D020254:Tooth Ankylosis / Q000209:etiology / Q000473:pathology; D014092:Tooth Root / Q000293:injuries* / Q000473:pathology; D019415:Torque; D014945:Wound Healing / Q000502:physiology
chemical_list: D004396:Coloring Agents; D005456:Fluorescent Dyes