How to improve root canal filling in teeth subjected to radiation therapy for cancer

Braz Oral Res. 2018 Nov 29:32:e121. doi: 10.1590/1807-3107bor-2018.vol32.0121.

Abstract

The aim of this study was to evaluate the influence of radiation therapy on root canal sealer push-out bond strength (BS) to dentin and the sealer/dentin interface after different final irrigation solutions (NaOCl, EDTA, and chitosan). Sixty-four maxillary canines were distributed into two groups (n=30): non-irradiated and irradiated with 60 Gy. Canals were prepared with Reciproc-R50 and subdivided (n=10) for final irrigation (NaOCl, EDTA, chitosan) and filled. Three dentin slices were obtained from each root third. The first slice of each third was selected for BS evaluation, and the failure mode was determined by stereomicroscopy. SEM analysis of the sealer-dentin interface was performed in the remaining slices. Two-way ANOVA and Tukey's tests (α=0.05) were used. Lower BS (P<0.0001) was obtained after irradiation (2.07±0.79 MPa), regardless of the final irrigation solution used. The NaOCl group (P<0.001) had the lowest BS in the irradiated (1.68±0.72) and non-irradiated (2.39±0.89) groups, whereas the EDTA (irradiated: 2.14±0.77 and non-irradiated: 3.92±1.54) and chitosan (irradiated: 2.37±0.73 and non-irradiated: 3.51±1.47) groups demonstrated a higher BS (P<0.05). The highest values were observed in the coronal third (3.17±1.38) when compared to the middle (2.74±1.36) and apical ones (2.09±0.97)(P<0.0001). There were more cohesive failures and more gaps in irradiated specimens, regardless of the final solution. The present study showed that radiation was associated with a decrease in BS, regardless of the final solution used, whereas chitosan increased BS in teeth subjected to radiation therapy.

Publication types

  • Evaluation Study

MeSH terms

  • Analysis of Variance
  • Chitosan / chemistry
  • Dental Bonding / methods*
  • Dental Restoration Failure
  • Dentin / drug effects*
  • Dentin / radiation effects*
  • Edetic Acid / chemistry
  • Epoxy Resins / chemistry
  • Epoxy Resins / radiation effects*
  • Head and Neck Neoplasms / radiotherapy
  • Humans
  • Materials Testing
  • Microscopy, Electron, Scanning
  • Reproducibility of Results
  • Root Canal Filling Materials / chemistry
  • Root Canal Filling Materials / radiation effects*
  • Root Canal Irrigants / chemistry
  • Root Canal Irrigants / radiation effects*
  • Sodium Hypochlorite / chemistry
  • Statistics, Nonparametric
  • Surface Properties / drug effects
  • Surface Properties / radiation effects
  • Tooth Root / drug effects
  • Tooth Root / radiation effects

Substances

  • Epoxy Resins
  • Root Canal Filling Materials
  • Root Canal Irrigants
  • epoxy resin-based root canal sealer
  • Chitosan
  • Edetic Acid
  • Sodium Hypochlorite