Matrix Metalloproteinase Expression in Teeth with Apical Periodontitis Is Differentially Modulated by the Modality of Root Canal Treatment

Paula-Silva, Francisco Wanderley Garcia; da Silva, Léa Assed Bezerra; Kapila, Yvonne Lorraine

doi:10.1016/j.joen.2009.10.030

« Previous Next »Journal of Endodontics
Volume 36, Issue 2 , Pages 231-237, February 2010

Matrix Metalloproteinase Expression in Teeth with Apical Periodontitis Is Differentially Modulated by the Modality of Root Canal Treatment

Francisco Wanderley Garcia Paula-Silva, DDS, MSc, PhD
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, Michigan
- Department of Pediatric Clinics, Preventive and Social Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
Léa Assed Bezerra da Silva, DDS, MSc, PhD
- Department of Pediatric Clinics, Preventive and Social Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
Yvonne Lorraine Kapila, DDS, PhD
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, Michigan
- Address requests for reprints to Yvonne L. Kapila, DDS, PhD, Associate Professor, Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, 1011 N University Ave, Ann Arbor, MI 48109-1078.

Abstract

Introduction

The objective of this study was to investigate the expression of matrix metalloproteinases (MMPs) in apical periodontitis and during the periapical healing phase after root canal treatment.

Methods

Apical periodontitis was induced in dog teeth, and root canal treatment was performed in a single visit or by using an additional calcium hydroxide root canal dressing. One hundred eighty days after treatment the presence of inflammation was examined, and tissues were stained to detect bacteria. Bacterial status was correlated to the degree of tissue organization, and to further investigate molecules involved in this process, tissues were stained for MMP-1, MMP-2, MMP-8, and MMP-9. Data were analyzed by using one-way analysis of variance followed by Tukey test or Kruskal-Wallis followed by Dunn test.

Results

Teeth with apical periodontitis that had root canal therapy performed in a single visit presented an intense inflammatory cell infiltrate. Periapical tissue was extremely disorganized, and this was correlated with the presence of bacteria. Higher MMP expression was evident, similar to teeth with untreated apical periodontitis. In contrast, teeth with apical periodontitis submitted to root canal treatment with calcium hydroxide presented a lower inflammatory cell infiltrate. This group had moderately organized connective tissue, lower prevalence of bacteria, and lower number of MMP-positive cells, similar to healthy teeth submitted to treatment.

Conclusions

Teeth treated with calcium hydroxide root canal dressing exhibited a lower percentage of bacterial contamination, a lower MMP expression, and a more organized extracellular matrix, unlike those treated in a single visit. This suggests that calcium hydroxide might be beneficial in tissue repair processes.

Key Words: Apical periodontitis, calcium hydroxide, matrix metalloproteinases, root canal treatment, single visit