title: Intracanal bisphosphonate does not inhibit replacement resorption associated with delayed replantation of monkey incisors.
abstract: Progressive replacement resorption following delayed replantation of avulsed teeth has proved to be an intractable clinical problem. A wide variety of therapeutic approaches have failed to result in the predictable arrest of resorption, with a good long-term prognosis for tooth survival. Bisphosphonates are used in the medical management of a range of bone disorders and topically applied bisphosphonate has been reported to inhibit root resorption in dogs. This study evaluated the effectiveness of a bisphosphonate (etidronate disodium) as an intracanal medicament in the root canals of avulsed monkey teeth, placed before replantation after 1 h of extraoral dry storage. Incisors of six Macaca fascicularis monkeys were extracted and stored dry for 1 h. Teeth were then replanted after canal contamination with dental plaque (negative control) or after root canal debridement and placement of etidronate sealed in the canal space. A positive control of calcium hydroxide placed 8-9 days after replantation was also included. All monkeys were sacrificed 8 weeks later and block sections were prepared for histomorphometric assessment of root resorption and periodontal ligament status. Untreated teeth showed the greatest extent of root resorption (46% of the root surface), which was predominantly inflammatory in nature. Calcium hydroxide treated teeth showed the lowest overall level of resorption (<30% of the root surface), while the bisphosphonate-treated group was intermediate (39%). Ankylosis, defined as the extent of the root surface demonstrating direct bony union to both intact and resorbed root surface, was the lowest in the untreated control group (15% of the root surface), intermediate in the calcium hydroxide group (27%) and the highest in the bisphosphonate group (41%). Bony attachment to the tooth root was divided approximately equally between attachment to intact cementum and to previously resorbed dentin. Overall, bisphosphonate resulted in a worse outcome than calcium hydroxide in terms of both root resorption and ankylosis.
authors.affiliation: Department of Conservative Dentistry, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia. thongyl@um.edu.my
authors.forename: Yo Len
authors.initials: YL
authors.lastname: Thong
authors.forename: Harold H
authors.initials: HH
authors.lastname: Messer
authors.forename: Rosnah Binti
authors.initials: RB
authors.lastname: Zain
authors.forename: Lip Hean
authors.initials: LH
authors.lastname: Saw
authors.forename: Lai Thong
authors.initials: LT
authors.lastname: Yoong
mesh_terms: D000818:Animals; D002126:Calcium Hydroxide / Q000008:administration & dosage / Q000627:therapeutic use; D003739:Dental Cementum / Q000473:pathology; D003773:Dental Plaque / Q000473:pathology; D003804:Dentin / Q000473:pathology; D004164:Diphosphonates / Q000008:administration & dosage / Q000627:therapeutic use*; D012968:Etidronic Acid / Q000008:administration & dosage / Q000627:therapeutic use; D005260:Female; D007180:Incisor / Q000293:injuries*; D008252:Macaca fascicularis; D008297:Male; D008768:Methylmethacrylates / Q000627:therapeutic use; D010513:Periodontal Ligament / Q000473:pathology; D012387:Root Canal Filling Materials / Q000627:therapeutic use*; D012389:Root Canal Obturation / Q000379:methods; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D012391:Root Resorption / Q000473:pathology / Q000517:prevention & control*; D013997:Time Factors; D020254:Tooth Ankylosis / Q000473:pathology / Q000517:prevention & control; D014084:Tooth Avulsion / Q000628:therapy*; D014090:Tooth Replantation / Q000379:methods*; D014092:Tooth Root / Q000473:pathology; D016896:Treatment Outcome; D015035:Zinc Oxide-Eugenol Cement / Q000627:therapeutic use
chemical_list: D004164:Diphosphonates; D008768:Methylmethacrylates; D012387:Root Canal Filling Materials; D015035:Zinc Oxide-Eugenol Cement; C031667:IRM cement; D012968:Etidronic Acid; D002126:Calcium Hydroxide