Micro-computed tomographic evaluation of dentinal microcracks in response to progressive taper enlargement in root canals of maxillary molars.

Aim: To investigate the development of dentinal microcracks resulting from the progressive enlargement of the buccal canals of maxillary molars with and without the MB2 canal employing instruments with the same tip and four different tapers.

Methodology: Twenty maxillary molars with (n = 10) and without (n = 10) the MB2 canal underwent micro-CT scanning. Their mesiobuccal and distobuccal canals were sequentially enlarged using nickel-titanium instruments with sizes 25/.