A micro-computed tomographic evaluation of dentine thicknesses of first molar roots: A review of the literature with illustrative cases

Thin dentinal walls of first molars can significantly impact the success and outcomes of endodontic procedures, including root canal treatment. Root canal treatment is commonly performed on first molars, which are prone to decay due to their early eruption and complex occlusal structure. The treatment entails a series of mechanical and chemical disinfection techniques where the root canal spaces are enlarged and can be compromised by perforations leading to infection, inflammation, and eventual tooth loss. The thinner the dentine, the greater the likelihood of perforation. ‘Danger zones’ have been identified as the distal aspect of mesial/mesiobuccal roots and the mesial aspect of distal roots. Knowledge of dentine thickness patterns in dental roots and understanding factors that influence dentine thickness can help reduce the risk of perforation and improve treatment outcomes. This literature review gives an overview of various aspects of the dentine thickness of the maxillary and mandibular first permanent molar. The content is supported by illustrative micro-CT images and clinical cases. Treating physicians should take note that variations in dentine thicknesses have been reported between sexes, with aging and among populations, but unfortunately no studies on dentine thickness could be found specifically for the South African context.