Comparison of the effectiveness of the protaper system versus hand instrumentation in endodontic retreatment: a scanning electron microscopy study

Introduction: Several rotary systems have been evaluated for removal of endodontic filling materials from the canal. Moreover, studies focusing on the comparison of the effectiveness of rotary systems versus hand instrumentation have yielded mixed results in terms of the efficacy and amount of time required by each technique. Objective: To compare the effectiveness of a nickel-titanium rotary system and of hand instrumentation using stainless steel files and Gates-Glidden burs in the removal of gutta-percha from root canals, as well as the time required to complete the procedure by each method. Material and methods: Forty single-rooted teeth were prepared and obturated then divided in two groups, according to the method employed for removal of the gutta-percha: ProTaper Universal rotary retreatment system (rotary instrumentation) and stainless steel hand files with Gates-Glidden burs (hand instrumentation). The time required to remove gutta-percha by each method was recorded. Roots were then sectioned lengthwise and the apical, middle, and coronal thirds were analyzed by SEM under two magnifications: x400 and x1,000. Results: Rotary instrumentation promoted better cleansing compared with hand instrumentation. The apical third was less clean than the coronal and middle thirds (Kruskal-Wallis p < 0.05). Rotary instrumentation was faster than hand instrumentation (Tukey p < 0.05). Conclusion: Although none of the methods promoted complete cleanliness of the canal walls, ProTaper Universal system showed better results and was faster than hand instrumentation.

The importance of microsonics concept for optimization of endodontic retreatment outcome: a case report

Introduction: During the past few decades, the endodontic treatment has benefited from the development of new techniques and devices, which have improved the outcome and predictability. Important attributes such as the operating microscope and ultrasonics have found indispensable applications in a number of dental procedures in endodontics. Objective and case report: This study describes a case of endodontic retreatment of a maxillary first molar in which the second mesiobuccal canal could be located by extending the access to the mesial direction further than usual and by a closer inspection of the pulp chamber floor. Conclusion: The "microsonics concept" has enhanced the quality of endodontic treatment and retreatment, becoming increasingly more useful in applications such as localization of root canal orifices.