Predentine is not a reliable barrier against internal root resorption in the presence of inflammation

Abstract

Introduction: Predentine has traditionally been perceived as a protective barrier against internal resorption in dental tissues. However, recent observations suggest that this barrier may be compromised under pathological conditions, particularly in the presence of inflammation. The present study explored the histological changes in teeth affected by internal resorption, and examined the role of predentine in resisting resorptive activity.

Methods: The study utilised 44 extracted human teeth with varying degrees of caries involvement and pulpal inflammation. Longitudinal serial sections were prepared for histological examination. Haematoxylin and eosin staining was used to observe tissue morphology, while a modified Brown and Brenn staining technique was employed to identify bacteria and their infiltration status. The focus was on identifying resorptive lacunae, odontoclast activity, and the integrity of the predentine layer.

Results: Histological analysis revealed resorptive activity in 23 out of 44 teeth. Odontoclasts were frequently observed in close contact with predentine, particularly in areas of inflammation. Despite the presence of predentine, resorption extended into the underlying mineralised dentine, challenging the notion of predentine as an impermeable barrier. Bacterial colonisation was evident in necrotic areas, correlating with regions of active resorption.

Conclusion: The findings suggest that predentine may not be as effective a barrier against internal resorption as previously thought, particularly in inflamed conditions. Future research should aim to elucidate the mechanisms underlying odontoclast activity and develop strategies to prevent or mitigate internal resorption in clinical practice.

Clinical significance: This study highlights the need for early intervention in cases of dental inflammation to prevent internal resorption, as predentine may not provide sufficient protection in compromised conditions.

Keywords: Internal root resorption; Odontoclasts; Predentine; Pulp inflammation; Root canal infection.