Calcium hydroxide dressing residues after different removal techniques affect the accuracy of Root-ZX apex locator

Effectiveness of a novel chelating agent in removing calcium hydroxide using conventional and passive ultrasonic irrigation techniques

Background

The present in vitro study aimed to compare the efficacy of a 25% copolymer of acrylic acid and maleic acid [poly(AA-co-MA)] and 17% of ethylenediaminetetraacetic acid (EDTA) in removing calcium hydroxide (CH) from root canals using the master apical file (MAF) and passive ultrasonic irrigation (PUI).

Material and Methods

Fifty-eight teeth were dressed with CH. After 10 days, CH was removed using MAF+EDTA, MAF+poly(AA-co-MA), PUI+EDTA, and PUI+poly (AA-co-MA) (n=12). Ten teeth were used as controls. Residual CH was evaluated using a four-grade scoring system. Data analysis was performed using the Mann-Whitney U, Friedman, and Dunn-Bonferroni tests.

Results

In the MAF and PUI groups, there was no significant difference in the CH scores between EDTA and Poly(AA-co-MA) (p<0.083). Although EDTA and poly(AA-co-MA) had lower CH scores when used with PUI, no significant difference was found between the two agents (p<0.083).

Conclusions

Poly(AA-co-MA) did not remove significantly more CH than EDTA when used with MAF or PUI. Key words:Calcium hydroxide, Ethylenediaminetetraacetic acid, Acrylic acid, Maleic acid.

Endodontic cement penetration after removal of calcium hydroxide dressing using XP-endo finisher

We aimed to evaluate the penetration of endodontic cement following the removal of calcium hydroxide (Ca(OH)2) dressing using the XP-endo Finisher in association with different irrigating solutions. Sixty premolars were instrumented and applied with a Ca(OH)2 dressing. To remove Ca(OH)2, the teeth were divided into six groups, each with a different volume of sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA), as well as solution stirring time with XP-endo Finisher (0, 30, and 60 sec). Root canals were filled using the lateral condensation technique. Fluorescein dye was added to the cement for microscopic laser scanning analysis. In the generated images, linear measurements were taken in micrometers, and their averages were calculated. To analyze the perimeter penetration ratio of the cement, the total perimeter of the canal and the segment of the total perimeter of the canal where the endodontic cement penetrated into the dentinal tubules were measured in micrometers. We found that using an XP-endo Finisher in irrigation was more effective than using a needle and syringe during the extension and penetration of endodontic cement. Shaking with XP-endo Finisher with 17% EDTA increased the extent and perimeter of the penetration of the endodontic cement into the dentinal tubules. However, using the XP-endo Finisher with EDTA only was more efficient than using the instrument interchangeably in NaOCl and EDTA. Although XP-endo Finisher contributes to the removal of Ca(OH)2, none of the protocols or instruments used removed all Ca(OH)2 from the root system.

Influence of Apical Patency, Coronal Preflaring and Calcium Hydroxide on the Accuracy of Root ZX Apex Locator for Working Length Determination: An In Vitro Study

Aim:

One of the main steps in a successful endodontic treatment is determining the correct working length (WL) of the root canal. In this regard, electronic apex locators (EAL) have been widely used for measuring the WL. The accuracy of EALs in determining the WL may be influenced by various factors. This study is aimed to evaluate the effects of apical patency, coronal preflaring, and calcium hydroxide on the accuracy of the EAL.

Materials and Methods:

In this in vitro study, 20 central incisor single-rooted human teeth with fully formed apex were considered. Then, samples were randomly divided into two study groups, ten samples in each group. The WL was determined and recorded at 0.5 mm distance to the apex using Root ZX apex locator before and after creating patency, coronal preflaring, and calcium hydroxide administration. All WLs were measured separately for each tooth and reviewed independently by two experienced operators with extensive experience in using EALs. Paired t test and Wilcoxon signed-rank test were applied and the significant level was at .05.

Results:

Statistical analysis of the obtained data showed a significant decline in the WL after apical patency and coronal preflaring ( P < .05). Moreover, WL exhibited a significant enhancement after calcium hydroxide application ( P < .05).

Conclusion:

Apical patency and coronal preflaring increased the accuracy of apex locators in determining the WL of the teeth. Besides, calcium hydroxide residues in the root canal reduced the accuracy of the apex locator.

Efficacy of glycolic acid for the removal of calcium hydroxide from simulated internal Resorption cavities

OBJECTIVES

This study evaluated the efficacy of 5% and 10% glycolic acid solutions for the removal of calcium hydroxide medicament from artificial internal resorption cavities.

MATERIALS AND METHODS

A total of 170 human maxillary premolars were selected and artificial internal resorption cavities were prepared using round burs and 37% orthophosphoric acid in the apical third of the root halves. Entire canal and resorption cavity were filled with calcium hydroxide paste. Then, the specimens were assigned to 2 control groups or ten experimental groups according to the irrigating solutions used for medicament removal with and without activation with ultrasonic energy as following: 5% glycolic acid, 10% glycolic acid, 17% EDTA, and 10% citric acid and distilled water. The resorption cavities were examined under different magnifications using stereomicroscopy and scanning electron microscopy (SEM). The calcium hydroxide remnants in the resorption cavity were scored by 2 evaluators using a 4-scoring scale. The data were analyzed with Kruskal-Wallis H tests with 5% significance threshold.

RESULTS

There was no significant difference regarding the distribution of removal scores among non-activated solutions (P > 0.05). In activated groups, 10% glycolic acid irrigation removed significantly more amount of calcium hydroxide than EDTA and distilled water (P < 0.05). No significant difference was found between the efficacy of 10% glycolic and citric acid (P > 0.05). Citric acid, 5% glycolic acid, and EDTA showed similar removal scores (P > 0.05). Passive ultrasonic irrigation significantly improved calcium hydroxide removal scores in 10% glycolic acid, citric acid, and EDTA groups (P < 0.05). The SEM examination revealed that the specimens that were scored 0 are not entirely free of calcium hydroxide remnants.

CONCLUSION

Concentration of 10% glycolic acid removed significantly more calcium hydroxide paste from resorption cavities than EDTA when used with passive ultrasonic irrigation. Although passive ultrasonic irrigation favored medicament removal in all irrigating solutions, complete elimination of medicament remnants was unattainable.

CLINICAL RELEVANCE

This study showed the improved efficacy of ultrasonically activated 10% glycolic acid in removing the calcium hydroxide medicament from the internal resorption cavity.

Evaluation of the accuracy of different apex locators in determining the working length during root canal retreatment

Background. This study aimed to assess the accuracy of three electronic apex locators (EALs) (Dentaport ZX [J Morita, Tokyo, Japan], Propex Pixi [Dentsply Maillefer, Ballaigues, Switzerland], and iPex II [NSK, Tokyo, Japan]) during root canal retreatment. Methods. The root canal lengths of 90 extracted single-rooted human teeth were determined under a dental operating microscope at ×10 magnification. The actual working length (AWL) was 0.5 mm less than the root length. Electronic measurements were performed with the three EALs. The root canals were instrumented and filled to the actual working length using the lateral compaction technique. After seven days, the teeth were retreated until the retreatment file was applied to the root canal at the working length determined by EALs, and then, the three EALs were used for determining the retreatment working length. Data were analyzed using chi-squared and Kruskal-Wallis tests. Results. In the retreatment, the accuracy of EALs was reported at %83.3 for Dentaport ZX, %83.4 forPropex Pixi, and %80 for iPex II within a tolerance of 0.5± mm of the AWL. Conclusion. Under the limitations of this study, Dentaport ZX, Propex Pixi, and iPex II can be a useful adjunct during retreatment. Clinicians should be aware that residual materials in the root canal during retreatment can affect the accuracy of EALs.

Influence of calcium hydroxide residues after using different irrigants on the accuracy of two electronic apex locators: An in vitro study

BACKGROUND

The purpose of this study was to evaluate the effect of calcium hydroxide (Ca[OH] ₂) residues on the accuracy of two electronic apex locators (EALs) (Root ZX and Raypex 6) in the presence of different irrigants.

MATERIALS AND METHODS

In this an in vitro study Eighty single-rooted human mandibular premolars were selected. The crowns of the teeth were removed to standardize the working lengths (WLs). Actual WLs (AWLs) were recorded, and the root canals were shaped using protaper rotary instruments up to size F3. Then, the root canals were dried and filled with injectable Ca (OH) ₂ paste and the access cavities were temporarily sealed. Teeth were put into four alginate boxes, including two experimental groups (n = 30) and two control groups (n = 10). The pools of alginate were wrapped in wet gazes and stored at 37°C and 100% humidity for 7 days. Then, the root canals were exposed and Ca (OH) ₂ paste was removed by normal saline or 5.25% sodium hypochlorite irrigation followed by 17% ethylenediaminetetraacetic acid (EDTA), and the electronic WL (EWL) was measured by Root ZX and Raypex 6. Differences of EWL from AWL were calculated. Furthermore, the percentage of acceptable measurements (tolerance limit of ± 0.5 and ± 1 mm) was calculated for each apex locator. One-way ANOVA test with post hoc paired t-test and Chi-square test was used to analyze the data (P < 0.05).

RESULTS

The results showed that there was no significant difference between the accuracy of two EALs and irrigants (P > 0.05).

CONCLUSION

The present study revealed that no statistically significant differences were observed between the two apex locators after Ca(OH)₂ paste removal with different irrigants.

Evaluating the efficacy of different techniques and irrigation solutions for removal of calcium hydroxide from the root canal system: A scanning electron microscope study

Aim:

The aim of this scanning electron microscope study was to compare the efficacy of two techniques (EndoVac and EndoActivator) and two irrigating solutions (5.25% NaOCl in combination with 17% ethylenediaminetetraacetic acid vs. Savlon™) for removal of calcium hydroxide (CH) from the root canal walls.

Settings and Design:

The study was carried out in the specialty of conservative dentistry and endodontics.

Materials and Methods:

Forty single-canal human teeth were used. The specimens were de-coronated to obtain a standardized root length of 15 mm using a diamond disk. The canals were instrumented till F3 ProTaper and CH intracanal medicament placed in the root canal. One week later, teeth were randomly divided into one control group and six experimental groups according to different irrigation protocols with different techniques.

Statistical Analysis:

Kruskal–Wallis test was conducted to analyze the effect of different treatment measures with respect to three regions of tooth.

Results:

The results indicated that there was no statistically significant difference between the two irrigation solutions and two techniques.

Conclusion:

To achieve the best adaptation of filling material after root canal treatment, it is crucial to remove intracanal medication from the root canal walls. However, none of the irrigation regimens and different techniques were able to completely remove the CH from the root canal wall.

The Effect of File Size and Type and Irrigation Solutions on the Accuracy of Electronic Apex Locators: An In Vitro Study on Canine Teeth

Measurements of the root canal during endodontic treatment have a significant influence on the course of the therapeutic process as well as on its final result in both human and veterinary medicine. The apical constriction should be the termination point for the preparation and filling of the root canal. This research was conducted with the use of a Septodont kit consisting of a small chamber filled with the examined solution in which a healthy second incisor was placed. The step back method was applied for the root canal preparation and master apical file of 30 was used. The working length was 22 mm. The examination was conducted with the use of steel as well as nickel titanium hand instruments. Different irrigation solutions and two types of apex locators were used. Measurements of the working length of the root canal showed dependence on the size of the instrument. Examinations carried out in various environments showed that analogical measurements were obtained only for sodium hypochlorite solutions. In other environments the measured sections were shortened. Comparative examinations with the use of steel instruments demonstrated insignificant measurement differences. Compared to these results, the measurements in nickel titanium group were characterized by more considerable deviations.