Micro-CT characterisation of the furcation area in human primary molars.

Purpose: Non-instrumentation endodontic treatment precludes that an antibiotic paste, placed on the furcation area of primary molars, will be able to heal furcation lesions and treat an infected root canal. Thus, the aim of the study was to characterise the furcation area of primary molars using micro-CT.

Methods: Primary molars, extracted due to pathological conditions, were scanned, and after reconstruction, dentine thickness at the furcation area was measured, resorption gaps and accessory canals were quantified, and mean grey values at the furcation were compared with two other areas of root dentine in each specimen using ImageJ.

Results: Twenty-five maxillary first molars, 19 maxillary second molars, 13 mandibular first molars and 28 mandibular second molars were studied. All (n = 85; 100%) had resorption gaps, and mean dentine thickness at the furcation was 2.3 mm. Nineteen teeth (22.3%) had accessory canals, and in 16 (19.5%), these communicated the pulp chamber with the furcation. Of these, eight (42.1%) were maxillary first molars. No mandibular first molars presented accessory canals. Mean grey value of root dentine was lower (153.2 ± 18.2) than values at the furcation (157.7 ± 19.54) (Wilcoxon test, p < 0.05).

Conclusion: All primary molars had resorption gaps, and in many of them, communication between the pulp chamber and the furcation area by an accessory canal was detected. Furcation areas showed higher microradiographic density values than root dentine areas.