Are referred inaccessible human primary molar teeth really inaccessible?

Comparison of two pediatric rotary file systems and hand instrumentation in primary molar: An ex vivo cone-beam computed tomographic study

Background

Pulpal involvement, secondary to dental caries, is not uncommon and is a challenging task for pediatric dentists. Morphological differences in root canal of deciduous teeth increases the complexity of management. The aim of this study was to compare two rotary file systems and hand instrumentation for root canal preparation in regard to canal transportation, centering ability ratio, and dentin thickness using cone-beam computed tomography (CBCT).

Methods

A total of 72 canals from 24 freshly extracted mandibular deciduous second molars were divided into a set of 8 teeth, then prepared using 2 rotary files systems: the Kedo-S pediatric file system (Group A) and Pro AF Baby Gold file system (Group B) were compared to hand instrumentation (Group C). CBCT scans before and after root canal preparation were used to evaluate tested parameters. Instrumentation time for all three techniques was also measured using a chronometer.

Results

Although rotary file systems have shown superior results in root canal preparation as compared to hand instrumentation, no significant differences were observed between all the groups for canal transportation and dentin thickness at all three levels of prepared canals. A comparison of centering ability ratio between all the groups was found to be statistically significant only at the cervical level. A significant difference was observed between hand instrumentation using K-files (117.3 s) and both rotary systems (Kedo-S (81 s) and Pro AF Baby Gold (81.5 s)) in terms of canal preparation time (P < 0.001).

Conclusions

Both tested rotary systems and hand instrumentation demonstrated comparable canal preparation results, with differences that were statistically non-significant in most tested parameters, without shaping errors. However, both the rotary systems were more efficient and faster than hand instrumentation.

Root canal morphology of primary maxillary second molars: a micro-computed tomography analysis

AIM

Successful endodontic treatment of primary teeth requires comprehensive knowledge and understanding of root canal morphology. The purpose of this study was to investigate the root canal configurations of primary maxillary second molars using micro-computed tomography.

METHODS

Extracted human primary maxillary second molars (n = 57) were scanned using micro-computed tomography and reconstructed to produce three-dimensional models. Each root canal system was analysed qualitatively according to Vertucci's classification.

RESULTS

22.8% (n = 13) of the sample presented with the fusion of the disto-buccal and palatal roots; of these, Type V was the most prevalent classification. For teeth with three separate roots (n = 44), the most common root canal type was Type 1 for the palatal canal (100%) and disto-buccal canal (77.3%) and Type V for the mesio-buccal canal (36.4%). Overall, 7% (n = 4) of mesio-buccal canals were 'unclassifiable'.

CONCLUSION

The root canal systems of primary maxillary second molars were not only complex but had a range of configurations that may contribute to unfavourable clinical outcomes after endodontic treatment.