Frequency of two canals in maxillary second premolar tooth.

Objective: To determine the frequency of two canals in relation to age and gender as well as role of shift cone angle radiographic technique in maxillary second premolar tooth.

Design: A cross-sectional study.

Place And Duration Of Study: The study was conducted in Operative Department (Endodontic Department), Hamdard University Dental Hospital, Karachi, from January 2004 to February 2005.

Patients And Methods: One hundred and twenty patients were selected for the study, based on non-probability purposive sampling technique. Twenty patients were dropped out of the study and the data was analyzed for 100 patients. All patients were examined clinically as well as radiographically. Then the canals were opened to further confirm and treat the tooth. The findings were noted on a performa and then cross-tabbed for the significant difference.

Results: One hundred patients {43 males (43%) and 57 females (57%)} whose mean age was 36.2 (SD +/- 7.3} were treated. Forty (40) years was the age limit for dividing the patients into two groups. Out of 43 males, 27 (63%) were below 40 years and out of 57 females, 38 (67%) were below 40 years. Statistical analysis with Chi-square revealed no significant difference. Out of 43 males, 27 (63%) had two canals and out of 57 females, 30 (53%) had two canals with no significant difference between the two groups. Results of parallel X-ray were cross tabbed with shift cone angle technique and the difference was highly significant (Chi-square value 9.61 and p-value 0.002).

Conclusion: Frequency of two canals was high is not age or gender dependant. Shift cone angle technique should be used as radiographic support for the clinical examination to identify the number of canals. The second canal became apparent with shift cone technique in 78% cases where additional periapical radiographs with shift cone angle technique were taken.