An investigation of accessory canals in primary molars - an analytical study

To evaluate the number, anatomical morphology and patency of accessory canals in the furcation of carious primary molar teeth and to ascertain whether these anatomic variations contribute to endodontic infection.

The accessory canals were observed under radiovisiography or RVG (Phase 1), scanning electron microscopy or SEM (Phase 2) and light microscopy (Phase 3).

The prevalence of accessory canals was 34.3% with a mean ± SD of 0.73 ± 0.980 in Phase 1, 73.3% with a mean ± SD of 3.07 ± 3.151 in Phase 2 and 64.3% with a mean ± SD of 1.68 ± 2.405 in Phase 3. The results observed were Phase 1 vs Phase 2<0.001 (highly significant), Phase 1 vs Phase 3 0.110 (ns) and Phase 2 vs Phase 3<0.001 (highly significant) employing Wilcoxon signed-rank test. The canals were predominantly oval in shape and ranged from 1 μ to 225 μ in diameter. Only 7% canals were observed to be patent.

Accessory canals may not be the primary cause of transmission of infection in the inter-radicular area of primary molars. Other factors enhancing permeability of the pulpal floor may be of more significance and need evaluation on a larger scale.