Incidence of Dentinal Defects and Vertical Root Fractures after Endodontic Retreatment and Mechanical Cycling

• Published in: Iranian endodontic journal Vol. 12; no. 4; pp. 502 - 507
• Main Authors: De Carlo Bello, Mariana, Pillar, Rafael, Mastella Lang, Pauline, Michelon, Carina, Abreu da Rosa, Ricardo, Souza Bier, Carlos Alexandre
• Format: Journal Article
• Language: English
• Published: Iran Iranian Center for Endodontic Research 01.01.2017
• Subjects: Original; Retreatment; Endodontics; Root Canal; Defects
• ISSN: 1735-7497; 2008-2746
• DOI: 10.22037/iej.v12i4.16587

The aim of this study was to evaluate the incidence of dentinal defects and vertical root fractures (VRFs) after endodontic retreatment and mechanical cycling (MC). Two hundred mandibular premolars were selected. Forty teeth were left unprepared (control group). The remaining 160 root canals were prepared with ProTaper instruments and filled by using two different techniques [eighty with lateral compaction (LC) and eighty with single-cone (SC)]. Forty canals from each group (LC and SC) received no further treatment. The remaining eighty teeth were divided into two groups (LCR and SCR) ( =40) in order to undergo the removal of the root filling, re-preparation and refilling with lateral compaction and single-cone, respectively. All of the teeth were subjected to MC (1000000 cycles, 130 N, 2.2 Hz and 37 C). The roots were sectioned at 3, 6 and 9 mm from the apex and observed under 20× magnification. The defects were classified as: and . Statistical analysis was performed using the Fisher's Exact test and the -Squared tests ( =0.05). MC alone did not promote any other defects or VRFs. Experimental groups presented higher dentinal defects than the control group ( =0.021). Retreatment groups did not present a higher amount of dentinal defects than the groups that were subjected to the first treatment ( >0.05). Endodontic treatment and retreatment, regardless of the filling technique and MC, did not influence the occurrence of dentinal defects or VRFs in the human premolars.