Evaluation of potential apex locator induced electrophoresis.

INTRODUCTION: In 1890, Breuer applied an electrical field concept to root canals in an attempt at sterilization. Recently, Balson and Dovgan have renewed interest in the use of electricity to aid in canal disinfection. The purpose of this investigation is to determine if the use of the apex locator or apex locator in conjunction with low speed handpiece causes a previously unreported electrophoretic effect. MATERIALS: Forty low-fat, dried sirloin steak cubes separated into four groups of 10 and immersed in 5.25% sodium hypochlorite for two minutes while connected to 1) an apex locator with no batteries, 2) one with batteries, or an apex locator and low speed handpiece set at either 3) zero or 4) 800 rotations per minute. Samples were dried and percentage of weight loss was calculated. ANOVA and Tukey Multicomparison tests were performed for statistical significance of α ≤ 0.05. RESULTS: ANOVA test and Tukey Multicomparison tests showed that there was a significant difference (α ≤ 0.05) between the groups. They revealed statistically significant differences between 800 rotations per minute and all other groups. This study showed that there were no significant differences between an apex locator with no batteries, one used with batteries and one used in conjunction with the low speed handpiece at zero rotations per minute. However, it was shown that there was significantly more tissue dissolution with an apex locator with low speed handpiece at 800 rotations per minute compared to the first three groups. CONCLUSION: These results did not support the original hypothesis that the apex locator with or without the low speed handpiece has an electrophoretic effect. However, the results do support the use of sodium hypochlorite agitation for increased tissue dissolution.

Comparison of cone-beam computed tomography and periapical radiography in predicting treatment decision for periapical lesions: a clinical study.

Objectives. To compare the ability of endodontists to determine the size of apical pathological lesions and select the most appropriate choice of treatment based on lesions' projected image characteristics using 2 D and 3 D images. Study Design. Twenty-four subjects were selected. Radiographic examination of symptomatic study teeth with an intraoral periapical radiograph revealed periapical lesions equal to or greater than 3 mm in the greatest diameter. Cone-beam Computed tomography (CBCT) images were made of the involved teeth after the intraoral periapical radiograph confirmed the size of lesion to be equal to greater than 3 mm. Six observers (endodontists) viewed both the periapical and CBCT images. Upon viewing each of the images from the two imaging modalities, observers (1) measured lesion size and (2) made decisions on treatment based on each radiograph. Chi-square test was used to look for differences in the choice of treatment among observers. Results. No significant difference was noted in the treatment plan selected by observers using the two modalities (χ(2)(3) = .036, P > 0.05). Conclusion. Lesion size and choice of treatment of periapical lesions based on CBCT radiographs do not change significantly from those made on the basis of 2 D radiographs.

Cytotoxicity comparison of three current direct pulp-capping agents with a new bioceramic root repair putty.

INTRODUCTION: The purpose of this in vitro study was to compare the cytotoxicity of white mineral trioxide aggregate cement (AMTA, MTA-Angelus), Brasseler Endosequence Root Repair Putty (ERRM), Dycal, and Ultra-blend Plus (UBP) by using human dermal fibroblasts and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. METHODS: Cultured adult human dermal fibroblasts were exposed to multiple concentrations of material elutes. The test material samples were immersed and incubated in the culture medium for 2, 5, or 8 days at 37°C. The cytotoxic effects were recorded by using an MTT-based colorimetric assay. Positive and negative controls were used. The results were statistically examined by one-way analysis of variance and Tukey post tests. RESULTS: The cell viability of cultures exposed to all dilutions of AMTA, ERRM, and UBP was statistically similar to the negative control at 2 and 5 days. Only the Dycal-exposed specimens exhibited a statistically significant increase in cytotoxicity at the 2 initial evaluation periods. After exposure to the 8-day elutes, the respective percentage of cell survivability was 91% (Brasseler), 88% (MTA-Angelus), 76% (Ultra-blend Plus), and 37% (Dycal). CONCLUSIONS: From the data in this in vitro study, AMTA, ERRM, and UBP had statistically similar adult human dermal fibroblast cytotoxicity levels. Relative to the negative control, only Dycal was shown to have a statistically significant cytotoxic effect to adult human dermal fibroblasts at all tested intervals.

Cytotoxicity comparison of mineral trioxide aggregates and EndoSequence bioceramic root repair materials.

INTRODUCTION: The purpose of this bench top evidence level 5 in vitro study was to compare the cytotoxic effect of 2 brands of white mineral trioxide aggregate cement (ProRoot MTA and MTA-Angelus), Brasseler EndoSequence Root Repair Material, and Brasseler EndoSequence Root Repair Putty by using human dermal fibroblasts. METHODS: The cells were cultured in recommended culture conditions and exposed to the tested materials. The cytotoxic effects were recorded at an observation period of 24 hours by using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-based colorimetric assay. Results were analyzed by using one-way analysis of variance with significance of p < .05. RESULTS: All materials tested demonstrated cell viability ≥ 91.8%. Overall, there was no statistically significant difference in cell viability of ProRoot MTA, MTA-Angelus, and Brasseler EndoSequence Root Repair Material. However, there was a statistically significant difference negatively associated with the cell viability of human dermal fibroblasts in association with the Brasseler EndoSequence Root Repair Putty. CONCLUSIONS: The Brasseler EndoSequence Root Repair Materials were shown to have similar cytotoxicity levels to those of ProRoot MTA and MTA-Angelus.

Identify and determine the metrics, hierarchy, and predictive value of all the parameters and/or methods used during endodontic diagnosis.

A Consensus Conference on Terminology was convened by the American Association of Endodontists in Chicago on Oct 3, 2008 to review solicited papers on focused questions. This paper addressed the question: Identify and determine the metrics, hierarchy, and predictive value of all the parameters and/or methods used during endodontic diagnosis. The best available clinical evidence was used to determine the sensitivity, specificity, and predictive value of pulpal and periapical testing methods and imaging technologies. Diagnosis of dental pulp diseases suffers from operator's inability to test/image that tissue directly due to its location within dentin. In general, current pulp tests are more valid in determining teeth that are free of disease, but less effective in identifying teeth with pulp disease. Radiographic imaging is probably the most commonly used diagnostic tool to determine the status of root-supporting tissue, although interpretation of structural changes in the periradicular tissues is still considered unreliable.

Accuracy of film-based, digital, and enhanced digital images for endodontic length determination.

OBJECTIVE: This study compared the accuracy of D- and F-speed intraoral radiographs and digital and enhanced digital radiographic images for endodontic file length determination. STUDY DESIGN: Size 15 K-files were bonded in 51 canals of 34 human cadaver teeth. The distance from file tip to root apex was measured on D- and F-speed film and on unenhanced and enhanced digital images. The quality of the images was rated by the observers. Overlying cadaver bone and root structure were subsequently removed to expose the file tip for actual measurement to the apex. The distance measured on each image was compared with the actual measurement. ANOVA, Kruskal-Wallis, sign test, and Pearson correlation statistical analyses were applied. RESULTS: There were no significant differences in measurement accuracy among the 4 image types (P < or = .05). Subjective ratings showed a preference for the quality of enhanced digital images. Conclusion All 4 image types were similar in accuracy of file measurement. The image quality of enhanced digital images was subjectively superior to the others.

An endodontic perspective of contemporary infection control procedures.

This article reviews infection control procedures from an endodontic-specific perspective and offers comments and recommendations in context with the recently updated CDC Guidelines. Infection control implications for the following topics are reviewed: endodontic diagnosis, nonsurgical treatment, surgical treatment, and educational considerations. In areas of controversy, it is recommended that additional evidenced-based clinical research is needed to support the 2003 CDC Guidelines.

Evaluation of single-use rotary nickel-titanium instruments.

The purpose of this study was to analyze the number and types of defects observed in single-use, rotary nickel-titanium instruments. Every ProFile Series 29.04 taper nickel-titanium instrument used during a 4-week period in an endodontic specialty practice was collected. All instruments were new and were used by experienced clinicians during a single patient visit. The instruments were routinely used in a crown-down manner with RC Prep lubrication and copious irrigation. The instruments were used in a MicroMega 324 air motor in a 6:1 gear reduction contra-angle at 333 rpm. The instruments were collected, ultrasonically cleaned, sterilized, and inspected at x16 magnification. Torsional, flexural, and fracture defects were recorded and statistical analysis was performed using the Kruskal-Wallis one-way analysis of variance. A total of 786 ProFile Series 29 nickel-titanium rotary instruments were evaluated; 115 (14.63%) showed some type of defect after one clinical use. Size 3 instruments had the highest defect rate (22.66%) followed by size 5 (17.30%), size 2 (17.24%), and size 4 instruments (16.10%). However, there was no statistically significant difference. The size 6 and size 7 instruments showed minimal defects (2.38% and 4.76%, respectfully). Seven of 786 files had fractured (0.891%). There was no statistically significant difference in the type of failure seen within each file size. This study does show that defects can occur even with new files in the hands of experienced endodontists, and for absolute safety a single-use approach should be followed.

Contemporary endodontic retreatments: an analysis based on clinical treatment findings.

A prospective in vivo investigation was conducted to determine radiographic and clinical factors associated with contemporary nonsurgical endodontic retreatments. Approximately 1,100 failing endodontically treated teeth were screened to determine an appropriate treatment plan. Using magnification, 337 consecutive retreatment cases were evaluated and treated. The vast majority of the retreated cases involved multiple factors. Eighty-five percent of the cases presented with periradicular radiolucencies. Sixty-five percent of the cases demonstrated poor radiographic obturation quality. Associated pain was noted 51% of the time. Forty-two percent of the teeth had untreated canal space. It was statistically significant (Chi-square, p < or = 0.05) that additional canal space was located and treated in 89% of the cases that had previous radiographic asymmetrical obturations. Evidence of coronal leakage was noted in 13% of the retreated teeth. Tooth number, obturation materials, overfills, and previous surgical retrofillings were also recorded. Recommendations were made that might improve the rate of clinical success.