Efficacy of different irrigation and activation systems on the penetration of sodium hypochlorite into simulated lateral canals and up to working length: an in vitro study.

Apical Extrusion of Debris Using Self-Adjusting File, Reciprocating Single-file, and 2 Rotary Instrumentation Systems

Aim To investigate the impact of sequential irrigation procedures on accumulated hard tissue debris (AHTD) levels in canal systems in mesial roots of human mandiblar molars after instrumentation.

Methodology  Based on pre-scans in a micro-computed tomography (μCT) system, 20 extracted human mandibular molars with joining mesial root canals and an isthmus between these were selected. Canals were instrumented using the ProTaper rotary system until the F3 instrument reached working length. A 1% NaOCl solution was applied during instrumentation, followed by a final 5-mL flush to working length. Subsequently, canals were irrigated with 5 mL of 17% EDTA. Thereafter, passive ultrasonic irrigation (PUI) was performed using 1% NaOCl on three occasions each for 20 s. Percent values of total canal system volume filled with AHTD were calculated based on high-resolution scans after each irrigation step. Data was compared using repeated measure anova followed by paired t-test for individual comparisons. Bonferroni’s correction was applied for multiple testing; the alpha-type error was set at 1%.

Results  Instrumentation of the root canals in conjunction with 1% NaOCl irrigation left 6.9 ± 4.2 vol.% of the total canal system volume filled with AHTD. This value was significantly (P < 0.01) reduced to 4.9 ± 3.6 vol.% after EDTA irrigation. Subsequent PUI resulted in a further significant (P < 0.01) reduction to 3.7 ± 2.8 vol.%.

Conclusions  In this quantitative study on AHTD reduction, a significant effect of EDTA and PUI was shown. However, approximately half of the debris that accumulated during instrumentation remained in the canal system.

http://www.endoexperience.com/documents/ZenderIrrigation2010Paque-2.PDF

Accumulated hard tissue debris levels in mesial roots of mandibular molars after sequential irrigation steps.

Study on the influence of refreshment/activation cycles and irrigants on mechanical cleaning efficiency during ultrasonic activation of the irrigant

Aim
To evaluate the efficacy of four final irrigation protocols on the reduction of hard-tissue debris accumulated within the mesial root canal system of mandibular first molars using micro-CT analysis.

Methodology
Forty mesial roots of mandibular molars with a single and continuous isthmus connecting the mesiobuccal and mesiolingual canals (Vertucci's Type I configuration) were selected and scanned at a resolution of 8.6 μm. Canals were enlarged sequentially using WaveOne Small and Primary instruments activated in reciprocating motion without intracanal irrigation to allow debris to accumulate within the mesial root canal system. Then, specimens were anatomically matched and distributed into four groups (n = 10), according to the final irrigation protocol: apical positive pressure (APP), passive ultrasonic irrigation (PUI), Self-adjusting File (SAF) and XP-endo Finisher (XPF). The final irrigation procedures were performed over 2 min using a total of 5.5 mL of 2.5% NaOCl per canal. Reconstructed data sets were coregistered, and the mean percentage reduction of accumulated hard-tissue debris after the final irrigation procedures was compared statistically between groups using the anovapost hoc Tukey test with a significance level set at 5%.

Results
Reduction of accumulated hard-tissue debris was observed in all groups after the final irrigation protocol. Overall, PUI and XPF groups had higher mean percentage reductions of accumulated hard-tissue debris (94.1% and 89.7%, respectively) than APP and SAF groups (45.7% and 41.3%, respectively) (P   0.05) or APP and SAF groups (P > 0.05).

Conclusions
The PUI technique and XP-endo Finisher instrument were associated with significantly lower levels of AHTD compared with conventional irrigation and the modified SAF system protocol in mesial root canals of mandibular molars.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1111/iej.12630

Ex vivo evaluation of four final irrigation protocols on the removal of hard‐tissue debris from the mesial root canal system of mandibular first molars

AIM: To evaluate whether passive ultrasonic irrigation (PUI) of 2.5% NaOCl would dissolve necrotic pulp tissue from simulated accessory root canals (SACs) better than passive placement of the irrigant, when temperature was equilibrated between the two treatments. METHODOLOGY: Transparent root canal models (n = 6) were made from epoxy resin. SACs of 0.2 mm diameter were placed at defined angles and positions in the mid-canal and apical area. SACs were filled with necrotic bovine pulp tissue. PUI was performed five times for 1 min each with irrigant replenishment after every minute. Main canal temperature was measured after each minute, and a digital photograph was taken. In control experiments, mock treatments were performed with the same set-up without activation of the file using heated NaOCl to mimic the temperature created by PUI. Experiments were repeated five times. Digital photographs were analysed for the distance of dissolved tissue into the SACs in mm. Overall comparison (sum of dissolved tissue from all five accessory canals) between treatments was performed using paired t-test. Differences between SAC angulation and position after PUI were investigated using anova/Bonferroni (alpha < 0.05). RESULTS: Passive ultrasonic irrigation caused a rise in irrigant temperature in the main canal to 53.5 +/- 2.7 degrees C after the fifth minute. PUI dissolved a total of 6.4 +/- 2.1 mm, mock treatment controlled for heat: 1.4 +/- 0.6 mm (P < 0.05). No significant influence of SAC position or angulation was found. CONCLUSIONS: Passive ultrasonic irrigation promotes positive tissue-dissolving effects beyond a rise in irrigant temperature.

/pdf/necrotic-pulp-tissue-dissolution-by-passive-ultrasonic-1se057rcjo.pdf

Necrotic pulp tissue dissolution by passive ultrasonic irrigation in simulated accessory canals: impact of canal location and angulation

https://www.zora.uzh.ch/id/eprint/25303/3/29303.pdf

Acoustic Hypochlorite Activation in Simulated Curved Canals

Paque F, Al-Jadaa A, Kfir A. Hard-tissue debris accumulation created by conventional rotary versus self-adjusting file instrumentation in mesial root canal systems of mandibular molars. International Endodontic Journal, 45, 413–418, 2012.



Abstract

Aim  To evaluate the accumulation of hard-tissue debris when using the Self-adjusting File (SAF) system in mesial roots of mandibular molars with isthmuses and to compare it with that occurring when the ProTaper file system was used.



Methodology  Forty extracted human mandibular molars with joining mesial root canals and an isthmus between the two canals were randomly assigned to two experimental groups and scanned using micro-computed tomography. Root canals in the control group (N = 20) were instrumented using the ProTaper rotary system until F3. Irrigation with 1 mL of 3% NaOCl solution was applied after each instrument. Root canals in the experimental group (N = 20) were prepared using the SAF for 4 min, with continuous irrigation (3% NaOCl, 4 mL min−1). After rescanning, canals in both groups were further irrigated with 5 mL of 17% EDTA for 2 min. After final scanning, the per cent value of total canal system volume filled with hard-tissue debris was calculated. Statistical analysis was performed using Mann–Whitney U-test; the alpha-type error was set at 1%.



Results  Instrumentation of the root canals with ProTaper left 10.1% (IQR 5.2) of the total canal system volume filled with hard-tissue debris while preparation with the SAF left 1.7% (IQR 1.6). This difference was highly significant (P < 0.0001). After subsequent EDTA irrigation, these values were significantly reduced (P < 0.01) to 7.9% (IQR 4.1) and 1.3% (IQR 0.8) in the ProTaper and SAF groups, respectively.



Conclusion  Preparation with the SAF system resulted in less hard-tissue debris accumulation in isthmus-containing root canal systems compared with instrumentation with ProTaper rotary files.

Hard-tissue debris accumulation created by conventional rotary versus self-adjusting file instrumentation in mesial root canal systems of mandibular molars.

https://www.zora.uzh.ch/id/eprint/102269/1/35_Ibrahim_Journal_of_Endodontics_2014.pdf

Three Root Canals in the Mesiobuccal Root of Maxillary Molars: Case Reports and Literature Review

AIMS: To assess the accuracy and sensitivity in detecting implants leakage with a gas-enhanced permeation test (GEPT) and to compare with a molecular- and a bacterial-based leakage tests.
MATERIALS AND METHODS: Three implants systems were tested (n = 20 per group): Nobel Biocare (NB), Astra Tech (AT) and Biomet 3i (B3i). Implants were mounted in PVC disks and were first tested for gas pressure change and infiltrated saline volume over 40 min. The same implants were then subjected to a molecular leakage evaluation using fluorescent Dextran for 28 days. After cleaning and sterilization, bacterial permeation (E. faecalis) was evaluated by selective media turbidity for another 28 days. Slopes in the pressure change and the perfused saline rate were used as a measure of leakage in the GEPT model and the times of positive events, that is, color change, after molecular and bacterial tests were recorded. Data were analyzed using Kolmogorov-Smirnov/Shapiro-Wilk, Kruskal-Wallis H and Spearman's Rho tests (P < 0.05).
RESULTS: The gas and saline (ml) leakage values accounted for 0.85 ± 0.71 and 0.56 ± 0.50 ml (AT), 0.23 ± 0.030 and 0.12 ± 0.20 ml (NB) and 0.01 ± 0.01 and 0 ± 0 ml (B3i), respectively, and were significantly different from each other (P < 0.001). Slope in the pressure change over time showed a significant positive correlation with the collected saline solution (r = 0.91; P < 0.001). Molecular and bacterial leakage was positive at the same implants, which also showed increased leakage values in the GEPT setup. The development of positive events in the timeline of the bacterial leakage evaluation corresponded well to the GEPT leakage model.
CONCLUSION: The GEPT proved to be a reliable method to quantify leakage. The B3i showed the best sealing among the tested systems.

Anas Al-Jadaa

Papers

Necrotic pulp tissue dissolution by passive ultrasonic irrigation in simulated accessory canals: impact of canal location and angulation

Acoustic Hypochlorite Activation in Simulated Curved Canals

Hard-tissue debris accumulation created by conventional rotary versus self-adjusting file instrumentation in mesial root canal systems of mandibular molars.

Three Root Canals in the Mesiobuccal Root of Maxillary Molars: Case Reports and Literature Review

Comparison of three in vitro implant leakage testing methods