Comparative evaluation of the dimensional compatibility of ISO #30/.06 gutta-percha cones from four different manufacturers using an endodontic gauge

Abstract

Aim: Gutta-percha is the most commonly used biocompatible obturation material in endodontics for the three-dimensional and hermetic sealing of the root canal system. However, despite the dimensions defined in the ISO 6877 standard, dimensional discrepancies between gutta-percha cones and endodontic files have been reported. The aim of this study was to comparatively evaluate the dimensional variability of ISO #30/.06 gutta-percha cones from four different manufacturers using an endodontic gauge.

Methodology: A total of 240 ISO #30/.06 gutta-percha cones (n = 60 per brand) from four manufacturers (ProTaper Ultimate, MetaBiomed, Diadent, and EndoArt) were evaluated. Cone diameters were measured at the D0, D5, D10, and D15 levels using a Woodpecker R1 Plus endodontic gauge. Based on the ISO 6877 nominal dimensions, measurements were categorized as undersized, within the nominal range, or oversized. Statistical analysis was performed using Pearson's chi-square and Fisher's exact tests with Bonferroni correction (p < 0.05).

Results: Dimensional discrepancies from the nominal ISO values were observed across all measurement levels, with statistically significant differences among the brands (p < 0.05). ProTaper Ultimate and MetaBiomed showed the highest compatibility with nominal dimensions, whereas EndoArt exhibited a consistently high proportion of undersized cones (57.1–67.2%) across all regions. Diadent showed a notably high proportion of oversized cones at the D15 level (66.7%). Effect sizes for between-brand comparisons were large at every level (Cramer's V = 0.386–0.503).

Conclusion: ISO #30/.06 gutta-percha cones from different manufacturers did not show complete dimensional compatibility. These discrepancies may adversely affect apical adaptation, particularly in single-cone obturation techniques, potentially reducing clinical success. The use of an endodontic gauge provides a practical means of objectively verifying cone–canal adaptation in clinical practice, helping to prevent microleakage and obturation errors.