Incidence and configuration of canal systems in the mesiobuccal root of Maxillary first and second molars

Canal morphology of maxillary molars: Clinical observations of canal configurations

“…With the advent of newer designs of ultrasonic instruments designed for more efficiency (Ruddle CPR), combined with dependable ultrasonic units (Spartan), the trough-ing process has become faster and cleaner. In most teeth, the location of MB2 canal orifices agree with the findings of several authors (2,3,7,8). The MB2 orifice openings were usually found mesial to an imaginary line between the MB 1 and palatal orifices, and commonly, about 2 to 3 mm palatal to the MB 1 orifice.…”

“…In approximately 16% of the teeth, the MB2 canal systems could not be fully instrumented and were thought to be a rudimentary canal that did not exist in the apical one-half of the root (9), have an acute angle, or be blocked by stones or other debris in the canal system (10). It is of interest to note the studies utilizing microscopes have reported a significantly higher percentage of MB2 canal system occurrences (3,8,11) than studies using other means of determination (1,(12)(13)(14).…”

“…The presence of a second (mesiobuccal (MB)) (MB2) canal in the MB root of the maxillary molars has been the subject of many discussions and studies (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). Hess and Zurcher's (1) landmark study in 1925 showed the mesial root of the lower first molar, and the MB root of the upper molars had the most ramifications of any teeth.…”

“…The results of these studies have shown from 18.6% (2) to 96.1% (3) occurrence of the fourth (MB2) canal in maxillary first molars, depending on which method was used. The literature shows both clinical (in vivo) and laboratory (in vitro) results (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) and that more MB2 canals can be found in the laboratory than were found clinically (4). In short, the incidence varies widely, depending on the method used: whether done with or without dye penetration, radiographically, various sectioning tech-niques, record reviews, different social groups, different age groups, with or without magnification, etc.…”

Frequência do quarto canal radicular em primeiros molares superiores tratados endodonticamente: estudo retrospectivo

“…Os resultados obtidos no presente estudo, quando comparados com a literatura científica [6][7][8] , apresentaram baixa frequência de constatação do quarto canal. Isso pode ser explicado pela ausência de meios auxiliares na prática clínica que contribuam na procura pelo quarto canal e também pela diferença no delineamento dos estudos.…”