Reaction of the lateral periodontium of dogs’ teeth to contaminated and noncontaminated perforations filled with mineral trioxide aggregate

By Holland R, Bisco Ferreira L, de Souza V, Otoboni Filho JA, Murata SS, Dezan E Jr

Date: 07/2007
Journal: JOE

Purpose: to evaluate the repair of noncontaminated and contaminated lateral root perforations sealed with MTA and the effect of temporary filling of the contaminated perforations with a bactericidal agent (calcium hydroxide– based dressing) before MTA sealing.

N= 30 premolars ( 2 dogs )

Materials and methods:

•After isolation, access cavity then pulp tissue was extirpated and root prepared biomechanically.

•Obturation was done using Sealapex sealer and lateral condensation of GP. •Perforation was made on the lateral surface of each premolar ( between the coronal and middle root thirds toward the bone )

•Teeth were divided into 3 groups equally:

Group 1 :  Perforations were sealed immediately with MTA after controlling the bleeding

Group 2:  The pulp chamber was left exposed to the oral cavity for 7 days then sealed with MTA

Group 3 : same as group 2, then filled with calcium hydroxide paste and cavit for 2 weeks, then repaired with MTA

•After 90 days the animals were killed and the mandibles were removed then mounted on microscope glass slides for histomorphologic analysis.

Most highlighted results:

Group 1: New cementum formation close to the perforation, PDL was partially organized with chronic inflammatory cell infiltrate, no microorganisms were present.

Group 2:  Most of the cases had no new cementum formation close to the wall of perforation, gram +ve microorganisms were observed

Group 3:  Newly formed cementum, presence of a chronic inflammatory cell infiltrate of great intensity and extension was observed, no microorganisms were present.

Clinical significance:

Immediate seal of perforations will result in better seal, thus better prognosis.