Damages to Radicular Dentin during Root Canal Filling and Retreatment Procedures: Analysis, Evaluation Methods and Methodological Issues

This review article focuses on some of the factors leading to damages of radicular dentin in the course of different root canal filling techniques and retreatment procedures. Conflicting results in literature exist regarding the effect of single-cone obturation, cold lateral condensation and thermomechanical compaction of gutta-percha in terms of stress generation onto the root canal wall. Experimental data is inconsistent concerning the incidence of root cracks after retreatment procedures performed with specifically designed nickel-titanium rotary systems. These contradictory statements are likely due to the methodological issues and sample selection utilized in the laboratory experiments. An attempt is made to summarize and analyse the existing data concerning various observational methods used for microcrack detection, pointing out their advantages, disadvantages and limitations.