Efficacy of flowable gel-type EDTA at removing the smear layer and inorganic debris under manual dynamic activation

Evaluation of the Efficacy of EDTA Chelation on Alveolar Bone Healing After Ultrasonic and Conventional Surgery Under Bisphosphonate Medication: A Rat Model

PURPOSE

The aims of the present study were 1) to investigate the effects of local ethylenediaminetetraacetic acid (EDTA) chelation on alveolar bone healing after systemic administration of bisphosphonates; and 2) to compare the healing in alveolar defects created with ultrasonic and conventional surgery.

MATERIALS AND METHODS

A total of 40 male Wistar rats were divided into 4 equal groups of 10 rats each (zoledronate and piezosurgery, zoledronate and bur, placebo and piezosurgery, and placebo and bur). The first 2 groups received weekly intraperitoneal injections of zoledronic acid (0.06 mg/kg), and the second 2 groups received saline solution for 4 weeks. After the last injections, horizontal defects 4 × 2 × 1 mm in size were created on the mandibular alveolar bone using piezosurgery or conventional bur surgery. The zoledronate groups received 10 minutes of local application of EDTA on 1 side and saline solution on the other side. In the placebo groups, only 1 side was treated (one half of the group with the bur and one half of the group with piezosurgery). All the rats were euthanized at 4 postoperative weeks for comparative histomorphometric evaluation of bone healing in the created defects.

RESULTS

Bone formation was found to be the greatest in the placebo groups (P < .05). Although a greater amount of bone formation was observed with piezosurgery and EDTA among the bisphosphonate-treated groups, the difference between the zoledronate groups was not statistically significant (P > .05). Similarly, no statistically significant difference was found between the use of piezosurgery and conventional bur surgery within the placebo groups (P > .05).

CONCLUSIONS

The findings of the present study revealed improved bone healing with the use of piezosurgery and EDTA chelation, although the difference did not reach statistical significance. Further research should be performed to clearly identify the role of EDTA as a chelating agent and in prevention of medication-related osteonecrosis of the jaws development.

In vitro evaluation of the contact angle formed between AH Plus, Hybrid Root Seal and mineral trioxide aggregate Plus sealer with dentin and gutta-percha

Aim:

The purpose of this study was evaluation and comparison of the contact angle of new root canal sealers – Hybrid Root Seal, mineral trioxide aggregate (MTA) Plus, and the conventional AH Plus sealer with dentin and gutta-percha.

Materials and Methods:

Two groups (Group D – dentin and Group G – gutta-percha) of 18 samples each were further randomly divided into 3 subgroups based on the type of sealer used, that is, AH Plus, Hybrid Root Seal, and MTA Plus. Contact angle measurement device (Phoenix 300) was used to measure the contact angle of the sealers on both dentin and gutta-percha. The results thus obtained were analyzed using one-way analysis of variance and Student's t-test.

Results:

MTA Plus recorded significantly higher values of contact angle on both the substrates, that is, dentin and gutta-percha when compared to AH Plus and Hybrid root canal sealer. The lowest value of contact angle in gutta-percha and dentin was shown by Hybrid root canal sealer and AH Plus, respectively.

Conclusion:

Both AH Plus and Hybrid Root Seal exhibited lower contact angle values, and hence, better wettability on both dentin and gutta-percha as compared to MTA Plus.

Influence of Mixed Additives on the Physicochemical Properties of a 5.25% Sodium Hypochlorite Solution: An Unsupervised Multivariate Statistical Approach

INTRODUCTION

This article reports for the first time the effects of multiple additives (polyethylene glycol 400, Triton X-100, benzalkonium chloride, and ethyl formate) on the surface tension, pH, and viscosity of 5.25% sodium hypochlorite (NaOCl) irrigant solution. Advanced statistical approaches based on unsupervised multivariate analysis (cluster analysis and principal component analysis) were used to quantify the variability of the physicochemical properties of the modified NaOCl solution for the first time in dentistry.

METHODS

Solutions of 5.25% NaOCl were modified with multiple additives in various concentrations, physicochemical parameters were measured at 22°C and 37°C, and the results were statistically analyzed to group the solutions and reveal the effects of additives.

RESULTS

Cluster analysis and principal component analysis revealed that pH and surface tension were the significant parameters (P < .05) for grouping the modified solutions. Four principal components, accounting for 90.6% of the total variance, were associated with flow characteristics (37.3%) determined by polyethylene glycol; the wetting property (22.5% and 10.5%), which was dependent on cationic and nonionic surfactant; and the antimicrobial effect (20.3%) influenced by ethyl formate. Varimax rotation of the principal components showed that the cationic surfactant (benzalkonium chloride) had significantly decreased surface tension compared with the nonionic surfactant (Triton-X). Although ethyl formate was introduced as an odor modifier, it had a significant effect on pH decrease and the occurrence of effervescence with O₂ and hypochlorous acid release.

CONCLUSIONS

The statistical results revealed that the 5.25% NaOCl irrigant solution should be modified with a mixture of 0.1% benzalkonium chloride, 1% ethyl formate, and 7% polyethylene glycol for obtaining a low pH and low surface tension.

Effects of EDTA gel and chlorhexidine gel on root dentin permeability

The aim of this study was to evaluate the effect of 24% ethylenediaminetetraacetic acid (EDTA) gel and 2% chlorhexidine gel (CHX) in dentin permeability and smear layer removal from root canals instrumented with NiTi rotary system using histochemical staining and scanning electron microscopy (SEM) analysis. Overall, 43 premolars were classified into two experimental groups, EDTA (n = 20) and CHX (n = 20), and a negative control (NC) (n = 3). All specimens were instrumented and the irrigant solutions were used after each file change. The EDTA group received a final rinse with 5-ml 1% NaOCl followed by a 5-ml 0.9% saline solution; the CHX group received a final rinse with 10-ml 0.9% saline solution; and the negative control group received a final rinse with only 0.9% saline solution. Fifteen teeth from each group were prepared for histochemical staining and evaluation of dentin permeability using the image-scanning software Axion Vision (v.4.8.2). Five remaining teeth were prepared for analysis using SEM for morphological analysis. The study found that 24% EDTA gel increased the permeability of dentin in all thirds evaluated and also demonstrated an increased cleaning ability, with dentinal walls free of smear layer and open dentinal tubules, as compared to 2% CHX gel. It was concluded that EDTA was efficient in cleaning the dentinal tubules and increased dentin permeability.