mechanical or cold lateral compaction: the incidence of dentinal defects

background: the incidence of dentinal defects may infl uence the outcome of root canal treatment. the aims of this study were to evaluate and compare the incidence of dentinal defects following root canal obturation with two different techniques. materials and methods: a total of 110 mesial roots of human mandibular fi rst molars were selected. twenty-seven roots were left unprepared as negative controls (ncs). the mesiobuccal canals of 83 roots were prepared using rotary instruments. twenty-seven roots were left unobturated as positive controls (pcs). twenty-eight roots were obturated with cold lateral compaction (clc) technique and the others were obturated with mechanical lateral compaction (mlc) technique. in the clc and mlc groups, spreader penetration depth was measured by an electromechanical testing machine in canals containing master gutta-percha cones. after root canal obturation, all the roots were sectioned horizontally at four levels from the apex and evaluated under a stereomicroscope at a magnifi cation of ×40. the presence of dentinal defects was noted. data were analyzed using the chi-square and t -tests. results: the number of defects was not signifi cantly different between the clc, mlc, and pc groups. the clc, mlc, and pc groups had signifi cantly more defects compared to the nc group. conclusion: according to the results of this study, the mlc and clc techniques were the same in producing dentinal defects. key words: dental internal fi t, dentin, gutta-percha, root canal obturation, tooth fractures