Methods: This study was a cross-sectional study based on the evaluation of periapical radiographs of maxillary second premolars which were endodontically treated in 2001-2002 academic year. A total of 253 teeth were randomly selected from patients' files that had undergone endodontic treatment performed by undergraduate students in Yeditepe University Dental Clinics. The patients were divided into two groups and forty years was the age limit for dividing. Group Ia included the teeth of patients who were younger than 40 years and had one canal and Group Ib were including the teeth which had two canals at the same group of age.Group IIa had those of patients' teeth that were older than 40 years of age and had one canal configuration while Group IIb had teeth with double canal configurations. Chi-Square test was performed.
Results:The results were statistically significant ( p<0.02 ) There were 75 teeth (60 %) in group Ia while there were 50 teeth ( 40 %) in group Ib. However, in patients over 40, the ratio of one canal configuration was rose up to 92 ( 78 %) in grop IIa , while only 36 ( 22 %) teeth had two canal configuration in group IIb. There was no teeth displayed three canals that called molarization.
Conclusion:It can be concluded that age is a determining factor in the root canal morphology of maxillary second premolars. One of the main reasons of obtaining contradictory results in studies concerning the root canal morphology of maxillary second premolars may be not to regard the age during study design