In vitro comparison of different reciprocating systems used during endodontic retreatment

Abstract

The present study evaluated the effectiveness of two reciprocating systems for the removal of root-filling material during endodontic retreatment. One hundred extracted mandibular premolars were prepared and root-filled with gutta-percha and sealer. Root fillings were removed with K-files according to the following techniques: Group A--hand instrumentation; Group B--Endo-Gripper system driven by compressed air; Group C--INTRAmatic 29CH + INTRA-LUX 3LD driven by compressed air; Group D--Endo-Gripper system driven by electric engine; Group E--INTRAmatic 29CH + INTRA-LUX 3LD driven by electric engine. The amount of filling debris on root canal walls was assessed radiographically and analysed using Auto CAD 2000 software. One-way anova and Duncan's test revealed statistically significant differences only in the middle third (P = 0.01); the best results being reached in group D. The apical third displayed the greatest amount of filling material debris, regardless of the technique used.

Effectiveness of rotary or manual techniques for removing a 6-year-old filling material

“…This is consistent with the findings of other studies (4,5,15,19) and was observed in both radiographic and microscopic analysis of samples. The apical third is a critical zone, requiring a considerable enlargement when cleaning and shaping the canals (20).…”

“…The choice of using a solvent in this study considered the existing literature (1,2,7,9,10,18) and the clinical relevance as it attempted to mimic genuine clinical situations that demand solvation. Some studies reported favorable results with the use of solvents to remove gutta-percha (17,19).…”

Removal of Gutta-percha from Root Canals Using the Self-Adjusting File

“…The consistently lower number of completely clean root canals at 2 mm compared with the other levels of the root may be explained by the difficulty of both instruments to work efficiently beyond the curvature of the root canal. This is in agreement with many studies that found that the apical part is the most difficult to clean (16)(17)(18).…”

Heat Release, Time Required, and Cleaning Ability of Mtwo R and ProTaper Universal Retreatment Systems in the Removal of Filling Material

“…For the NiTi instruments, filling removal in the cervical third was facilitated by dental anatomy in this region and speed of rotary instruments. Perhaps plasticization of gutta-percha caused by the temperature increase produced by the automated systems facilitated its removal from the coronal third, which is the area that concentrates the greatest filling volume (27). However, several studies have found that NiTi instruments are not more effective than hand instruments in removing filling material from the canal walls (19-22, 28, 29).…”