Histologic Assessment of Mineral Trioxide Aggregate as a Root-End Filling in Monkeys

By Torabinejad M, Pitt Ford TR, McKendry DJ, Abedi HR, Miller DA, Kariyawasam SP

Date: 01/1997
Journal: IEJ

Purpose:

  • To examine the periradicular response to MTA and amalgam as root-end fillings

Materials/Methods:

  • N= 12 maxillary incisors from 3 Cynomolgus monkeys
  • Rubber dam isolation. Cleaned and shaped and obturated with lateral condensation; access closed with amalgam. At 1 week, resection of apices between apical and middle thirds and 2 mm retropreparation completed. ½ of the  incisors were randomly selected to be restored with zinc-free amalgam, and ½ with MTA. Animals were given post-procedural Penicillin injection & 3 days of analgesics.
  • At 5 months, the  animals were sacrificed for histologic examination; 2 independent investigators reviewed the samples for concentration & predominant inflammatory cell type, extent and severity of inflammation, presence of bacteria and fibrous capsule, cementum deposition, and new bone formation adjacent to root end and filling material

Results:

  Dominant inflamm cell type Periradicular tissue inflam Fibrous capsule Bacteria presence (root end or canal) Cementum Bone formation
Amalgam -Lymphocytes-PMNs adjacent to amalgam 6/6 moderate to severe 6/6 0/6 6/6 over root end 0/6 over amalgam 6/6
MTA Lymphocytes 1/6 severe 0/6 0/6 6/6 over root end 5/6 over MTA (6th partially formed) 6/6

Clinical Significance:

Amalgam causes inflammation in the periradicular tissues and does not allow regeneration of dentoalveolar structures. MTA exhibits many favorable characteristics as a root-end filling material and should be chosen over amalgam, if available.