- Authors: Tanzilli JP, Nevins AJ, Borden BG.
- Title: A histologic study comparing Hydron and gutta-percha as root canal filling materials in monkeys.
- Journal: J Endod
- Date: Sep 1981
- Citation: 7(9):396-401
- Category: Obturation
- Evidence-based Ranking: 5
- Purpose/Objectives: To evaluate the histological response in the periapical tissues of monkeys to Hydron (a hydrophilic methacrylate based plastic) and gutta-percha.
Materials & Methods: 26 max. and mand. incisors in monkeys were prepared and placed into 4 groups. Group 1 - 10 teeth were over-instrumented and overfilled with Hydron; Group 2 - 4 teeth were over-instrumented and overfilled with gutta-percha and sealer; Group 3 - 7 teeth were under-instrumented and under-filled with Hydron; Group 4 - 5 teeth were under-instrumented and under-filled with gutta-percha and sealer. After 6 months the monkeys were euthanized and bone sections were prepared for histological examination. The analysis included the following criteria apical radiolucency, apical resorption, pulpal apical calcification, resorption of material within canal, presence of lymphocytes, and presence of macrophages.
Results: The most significant finding was the presence of a severe inflammatory reaction with a predominance of macrophages in the lesion in the Hydron overfill group. This is possibly the start of a self-perpetuating lesion in that the macrophages that had engulfed the foreign material were not being removed from the lesion. The gutta-percha overfill group also had a severe inflammatory reaction but the predominate cells were lymphocytes which is less suggestive of a self perpetuating lesion.
Authors Conclusion: While more studies need to be done Hydron is probably not a suitable obturation material.
Validity of Conclusion: No statistics but based on the study the conclusion is valid.