Effect of immediate intracanal placement of Ledermix Paste 1 on healing of replanted dog teeth after extended dry times Up to16% of all traumatic injuries to the permanent dentition result in avulsion (1).The prognosis of the replanted teeth depends on several factors, most importantlythelengthoftimebetweenexarticulation and replantation, as well as the storage conditions of the avulsed tooth (1^3). Damage sustained by the periodontalligament(PDL),whetherduetomechan- ical trauma, dehydration, or other causes a¡ecting the viability of the PDL cells, worsens the prognosis of the reimplanted tooth. Cell damage as a result of thetraumastimulatesanin£ammatoryresponsethat often results in an osteoclast-mediated external root resorption.The active resorptive process can rapidly degrade cementum and dentin with variable healing patterns. The¢rstreactionafterreplantationofatoothwitha damaged root surface is in£ammation. This in£am- matory response includes osteoclast-mediated root resorption in proportion to the initial damage. If the in£ammation is localized to a small area of the root and no additional in£ammatory stimulus is present, the damaged root surface will heal with cementum. On the other hand, if the damage to the root covers alargearea,directbone-to-rootfusionwilltakeplace in these areas and osseous replacement of the root will eventually result. Many avulsed teeth heal with Dental Traumatology 2002; 18: 316–321 Copyright # Blackwell Munksgaard 2002 Printed in Denmark. All rights reserved DENTAL TRAUMATOLOGY ISSN 1600–4469 316 Bryson EC, Levin L, Banchs F, Abbott PV,Trope M. E¡ect of immediate intracanalplacementof Ledermix Paste 1 on healing of replanted dog teeth after extended dry times. DentTraumatol 2002; 18: 316^321. # Blackwell Munksgaard,2002. Abstract ^ LedermixPaste 1 is apaste containing triamcinolone anddemeclocyclinewithdemonstratedanti-in£ammatoryactivity that may slow down resorptive processes after severe traumatic injuriestothe dentition. Atotalof 29 premolar roots of six mongrel dogs were extracted and instrumented with rotary nickeltitanium ¢les. Fifteen of these roots were then ¢lled with a calcium hydroxide (Ca(OH) 2 ) slurry and14 roots were ¢lled with LedermixPaste 1 paste. All accesses were sealed with glass ionomer and the roots replanted after an extraoral dry time of 60min. After 4months, the dogs were killed andthe roots prepared for histological evaluation. Five-micrometer thick cross-sectionsoftherootandsurroundingtissuetakenevery90 mm were evaluated forhealing. In addition, residual root masswas also measured to determine the extent of root structure loss for each treatment method.The Ledermix Paste 1 -treated roots had statisticallysigni¢cantly morehealingand less resorptionthanthe rootstreatedwith Ca(OH) 2 . Root ¢lling with Ledermix Paste 1 alsoresulted in signi¢cantlyless loss in root mass duetoresorption comparedtothose roots ¢lledwith Ca(OH) 2 . Immediate intracanalplacementof Ledermix Paste 1 atthe emergency visit afteranavulsioninjuryappearstodecreaseresorptionandincrease favorablehealing. E. C. Bryson 1 ,L.Levin 1 , F. Banchs 1 , P.V. Abbott 2 ,M.Trope 1 1 Department of Endodontics, School of Dentistry,UNC at Chapel Hill, Chapel Hill, NC 27955, USA; 2 Oral Health CentreofWAandSchoolofDentistry,TheUniversityof Western Australia,Perth, Australia Key words: dental trauma; periodontal healing; tooth avulsion; Ledermix Paste 1 Dr MartinTrope, Department of Endodontics,UNC at Chapel Hill,Chapel Hill, NC 27599, USA Tel: þ19199662707 Fax: þ19199666344 e-mail: martin_trope@dentistry.unc.edu Accepted 13 June, 2002