Influence of apical patency and filling material on healing process of dogs' teeth with vital pulp after root canal therapy

Roberto Holland,Arnaldo Sant'Anna Júnior,Mauro Juvenal Nery,Pedro Felício Estrada Bernabé,Eloi Dezan Junior,Valdir De Souza,José Arlindo Otoboni Filho,Sueli Satomi Murata

doi:10.1590/s0103-64402005000100002

Abstract

The purpose of this study was to investigate the periapical healing process of dogs' teeth with or without apical patency and after root canal filling with two types of sealers. Forty roots of premolars and incisors were utilized. The root canals were over-instrumented and dressed with a corticosteroid-antibiotic solution for 7 days to obtain ingrowth of periapical connective tissue into the canals. After this period, the tissue was removed in half of the specimens (groups with patency) and preserved in the other half (groups without patency). Canals were filled by lateral condensation technique with gutta-percha points and either a calcium hydroxide-based sealer (Sealer Plus) or a Grossman's cement (Fill Canal). The animals were killed by anesthetic overdose 60 days after the endodontic treatment and anatomic pieces were obtained and prepared for histologic examination. Data were evaluated in a blind analysis on the basis of several histomorphologic parameters. The groups without patency had better results (p=0.01) than those in which the ingrown connective tissue was removed. Comparing the sealers, Sealer Plus had significantly better results (p=0.01) than Fill Canal. In conclusion, both the apical patency (presence or absence) and the type of root canal filling material influenced the periapical healing process in dogs' teeth with vital pulp after root canal treatment. The use of a calcium hydroxide-based sealer in teeth without apical patency yielded the best results among the experimental conditions proposed.

Highlights

According to Ricucci and Langeland [1], many studies agree that partial pulpectomy may be preferred to total pulp removal in root canal treatment of teeth with vital pulp
The periodontal ligament (PDL) was well organized in 3 cases and partial organization was seen in the other specimens
Sealer Plus is a calcium hydroxide-based cement indicated for root canal filling

Summary

Introduction

According to Ricucci and Langeland [1], many studies agree that partial pulpectomy may be preferred to total pulp removal in root canal treatment of teeth with vital pulp. The findings of an in vitro investigation [5] showed that in 33.3% of the specimens evaluated, transportation of the apical foramen started with the use of a #10 K-file. According to these authors, it should be taken into consideration that the foramen normally emerges laterally to the apex, which means that the patency file will frequently act on one wall of the apical foramen, regardless of the file size or the motion applied to the handle of the instrument. Lambrianidis et al [6] analyzed the amount of extruded debris before and after enlargement of the apical constriction of root canals and observed that greater extrusion occurs when the constriction remains intact

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Conclusion