ABSTRACT
OBJECTIVES: The objectives of this study were to evaluate and compare the time-dependent chemical and ultramorphologic effects of ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) in young and old dentin. METHODS: Sixty-four teeth scheduled for extraction were collected from young (<30 years) and old (>60 years) patients. In 48 teeth, the dentin was reduced to a powder state and treated with EDTA or EDTA + NaOCl for 1 and 10 minutes, respectively. X-ray diffraction analysis was used to determine the changes in the composition of dentin through dissolution of hydroxyapatite (HAp). In the remaining teeth (n = 16), the root canals were prepared, bisected, and subjected to the same time-dependent treatment regimens. The changes in the number and area of dentinal tubules were calculated by image analysis. The data were analyzed statistically by paired t test and one-way analysis of variance, followed by Tukey honestly significant difference test at P = .05. RESULTS: In both young and old dentin, EDTA significantly decreased the HAp intensity at 1 and 10 minutes, whereas EDTA + NaOCl only decreased that of old dentin at 10 minutes. Pair-wise comparisons revealed that in old dentin, the reduction in HAp intensity after treatment with EDTA and EDTA + NaOCl was significantly greater at 10 minutes than at 1 minute, whereas in young dentin, a significant decrease was only observed in the EDTA/10-minute subgroup. Compared with their 1-minute counterparts, 10-minute treatment with EDTA + NaOCl significantly increased the tubular diameter and tubular area of old dentin. In young dentin, the tubular area and diameter values were not affected by treatment time (P > .05). CONCLUSIONS: In young root dentin, 10-minute treatment with EDTA + NaOCl does not significantly alter the chemical and ultramorphologic structure and thus appears to be unnecessary. In old dentin, extended treatment time with EDTA + NaOCl should be avoided owing to excessive demineralization and erosion. In both types of dentin, EDTA was not effective in complete removal of the smear layer.
Subject(s)
Chelating Agents/pharmacology , Dental Pulp Cavity/drug effects , Dentin/drug effects , Edetic Acid/pharmacology , Root Canal Irrigants/pharmacology , Sodium Hypochlorite/pharmacology , Adult , Age Factors , Dental Pulp Cavity/ultrastructure , Dentin/ultrastructure , Durapatite/analysis , Humans , Image Processing, Computer-Assisted , Microscopy, Electron, Scanning , Middle Aged , Smear Layer , Time Factors , X-Ray DiffractionABSTRACT
OBJECTIVE: The aim of this study was to compare the apical seal of the Single-cone ProTaper gutta-percha technique and the lateral compaction technique in combination with 3 sealers (AH-26, Apexit, and Sealite-Ultra). STUDY DESIGN: Seventy extracted single-root teeth were used. Root canals were prepared with ProTaper rotary instruments. Six groups were formed: (I) Single-cone ProTaper gutta-percha with AH-26; (II) lateral compaction technique with AH-26; (III) Single-cone ProTaper gutta-percha with Apexit; (IV) lateral compaction technique with Apexit; (V) Single-cone ProTaper gutta-percha with Sealite-Ultra; and (VI) lateral compaction technique with Sealite-Ultra. The fluid conductance of each specimen was measured after the 7th and 30th days using a fluid filtration method. RESULTS: When lateral compaction was performed, all sealers showed similar levels of leakage (P > .05). Using the single-cone technique, Sealite-Ultra showed more leakage than the others (P < .05). Comparing filling techniques, there was a significant difference only in the Sealite-Ultra groups (P < .05). CONCLUSION: Single-cone ProTaper gutta-percha and lateral compaction techniques showed similar sealing effect.
