From Caries Progression and Restoration Failures to Periapical Lesions in the Era of Precision.

KNOWLEDGE TRANSFER STATEMENT: Dental research can be thought of as a continuum of clinical observations that are dissected in the laboratory with answers that can be brought back to the clinic to change patient management. We believe this is the case for the use of adhesive systems and outcomes of dental treatment. Clinical observations related to negative outcomes have been tested in the laboratory and solutions have been proposed, with more precise implementation of these solutions possible when genomic approaches are added. Here we elaborate on this process based on the observations that lead to an attempt to inactivate metalloproteinase activity by dentin crosslinking.

Effectiveness of ProTaper, D-RaCe, and Mtwo retreatment files with and without supplementary instruments in the removal of root canal filling material.

AIM: To assess the efficacy of different retreatment rotary files in removing gutta-percha and endodontic sealer from canals. METHODOLOGY: Ninety straight single-rooted premolars were prepared up to a size 30 and filled with gutta-percha and sealer and then randomly assigned to six retreatment groups (n = 15). Groups I, III, and V were retreated using rotary systems ProTaper Universal Retreatment (PTUR), D-RaCe, and Mtwo Retreatment, respectively. Groups II, IV, and VI were retreated using the additional instruments F4, size 40, .04 taper RaCe, and size 40, .04 taper Mtwo, respectively. The roots were split vertically, and images of the halves were obtained using a high-resolution scanner and evaluated with AutoCAD software to calculate the percentage of residual material. Data were analyzed with Kruskal-Wallis and Student-Newman-Keuls tests using a 5% significance cutoff (P < 0.05). RESULTS: There were no statistically significant differences (P > 0.05) between groups when additional instruments were used. The percentage of residual material was lowest in the PTUR group and was statistically significant only when compared to the D-RaCe system (P = 0.0038). CONCLUSIONS: All root canals had residual filling material after retreatment even when additional instruments were used.