Expansion of Gutta-percha in contact with various concentrations of zinc oxide-eugenol sealer: A three-dimensional volumetric study using spiral computed tomography

Abstract

Aim:The purpose of this study was to evaluate the three-dimensional expansion of Gutta-percha (GP), at various powder/liquid ratios, of a zinc oxide-eugenol (ZOE)-based sealer using spiral computed tomography (SCT).Materials and Methods:Thirty-five freshly extracted human mandibular premolars were selected for this study. Cleaning and shaping were performed in all the teeth initially with hand K-files up to #25 and finally with RaCe rotary instruments (25/06). Teeth were randomly divided into five groups of 7 teeth each. Specimens were scanned using SCT. They were then viewed both cross-sectionally and longitudinally, with a constant thickness of 1 mm/slice. The volume of root canal in each tooth was estimated. Obturation was performed by GP points (25/04) and ZOE-based root canal sealer in all groups with different powder-liquid ratio. Groups 1, 2, 3, and 4, had powder/liquid ratio of 1:1, 1:2, 1:3, and 1:4, respectively, while in the control group, no sealer was used. The obturation was performed by sealer coated single cone GP. A second SCT scan was performed to determine the volume of GP and sealer in all four groups 1 day after obturation. The third and fourth SCT scans were taken 7 and 30 days after obturation, respectively. The mean volume of GP per group was calculated. Data were statistically analyzed using one-way ANOVA. Inter-group comparisons were done using Scheffe post hoc multiple comparisons test.Results:All groups with sealer showed expansion of GP at both 7th day and 30th day, which was statistically significant from the GP volume at 1st day. Groups 2 and 3 with powder/liquid ratio of 1:2 and 1:3 gave the highest mean volume values during 30 days period and showed significant expansion in comparison with Groups 1 and 4 with powder/liquid ratio of 1:1 and 1:4, respectively.Conclusion:Increasing the ratio of eugenol in sealer resulted in the volumetric expansion of GP. However, further studies should be performed to confirm the expansion of GP, leading to the achievement of fluid impervious seal.

The effect of four different intracanal medicaments on the push-out bond strength of root canal sealers

“…Our study recorded the highest push-out bond strength when calcium hydroxide was used as an intracanal medicament [ 13 ]. Other researchers had similar findings and stated that calcium hydroxide Ca(OH) 2 used as a treatment for 14 days showed satisfying effects on the bond strength of AH Plus to root dentin [ 14 – 18 ]. However, according to Amin et al , intracanal treatment with Ca(OH) 2 for a week showed no changes in the bond strength of AH Plus.…”

“…The reasons for the higher push-out bond strength of AH Plus might be due to a covalent linkage between an open epoxide ring and exposed amino groups in collagen protein, lower shrinkage while setting, long-term dimensional stability, and inherent volumetric expansion of AH Plus. These factors may contribute to a better AH Plus sealer bond strength [ 16 – 18 ].…”

Effect of Two Irrigants on Adaptability of Cross-Linked Gutta-Percha Core

“…Also, Gutta-core carrier appeared to offer better micromechanical retention than the ThermaFil carrier, since the gutta-core carrier is crosslinked gutta-percha [15,16] and so it is unlikely that any chemical interaction would develop between this and the alpha-phase gutta-percha of the coating so that avoid stripping of gutta-percha from the carrier during the insertion into the root canal space. This would result in reducing voids and adequate filling of the root canal space [15] . These findings were in agreement with other studies [16,18,19] which reported that gutta-core demonstrated significantly higher bond strength than ThermaFil.…”

“…Once the fit was verified, then the root canals of each subgroup were coated with a thin layer of Endofill sealer (Dentsply Maillefer, Brazil) with paper point and obturated with gutta-core. Subgroup B: Specimens were obturated with ThermaFil (Dentsply, Maillefer, USA), with a size 40 or 45 ThermaFil obturator using the same technique as in subgroup A, but the obturator was heated to 30 seconds in Therma-prep oven [15,16] .…”

A critical analysis of research methods and experimental models to study root canal fillings

“…According to them, the major limitation of this method was to differentiate the gutta‐percha from the sealer. A few other studies were published using this same tool to compare other techniques and materials (Anbu et al, 2010; Bhatt & Rajkumar, 2015; Jain & Ballal, 2019; Jindal et al, 2017; Kandaswamy et al, 2009) and to measure the expansion of gutta‐percha in contact with various concentrations of zinc oxide‐eugenol sealer (Chandrasekhar et al, 2011; Tilakchand et al, 2016). In general, voids were identified in all specimens and thermoplasticized gutta‐percha techniques resulted in better filling than cold techniques.…”