Efficacy of three different irrigation techniques in the removal of smear layer and organic debris from root canal wall: a scanning electron microscope study

Evaluation of smear layer removal of radicular Dentin in comparison with different irrigation devices: An in vitro study

Aim:

The aim of this study was to evaluate the efficacy of smear layer removal from the root canals using 2 ml of 5.25% sodium hypochlorite passive ultrasonic irrigation, EndoVac, and diode laser during endodontic therapy.

Materials and Methods:

Forty single-rooted human teeth were selected. Access cavity preparation was done. Working length was determined. Instrumentation was initiated with ISO hand files number 15 k file, followed by ProTaper rotary files size F3. Two milliliters of 5.25% NaOCl was used as an irrigant after every instrumentation, with a final flush of 17% EDTA, followed by a rinse with 3 ml of distilled water. Teeth samples were divided into four groups – Group I (n = 10) conventional irrigation with 5.25% NaOCl, 17% EDTA for 1 min, Group II (n = 10) instrumented and irrigated with ultrasonic activation for 1 min, Group III (n = 10) instrumented and irrigated with EndoVac for 1 min, Group IV (n = 10) (analyzed with irradiation of 2 W continuous wave of 910 nm diode laser). Teeth samples were then sectioned longitudinally. Scanning electron microscope examination of canals was done for evaluating smear layer at different levels. Statistical data analysis was done by one-way ANOVA test to evaluate the smear layer score at a significance level of P ≤ 0.05.

Results:

Group III and Group IV have a minimal amount of smear layer at the apical third when compared to Group I and Group II which was statistically significant with a P < 0.05.

Conclusion:

Diode laser and EndoVac performed better in removing the smear layer when compared with 2 ml of 5.25% sodium hypochlorite and ultrasonic irrigation.

Evaluating In Vitro Performance of Novel Nickel-Titanium Rotary System (TruNatomy) Based on Debris Extrusion and Preparation Time from Severely Curved Canals

INTRODUCTION

This laboratory-based study aimed to investigate the quantitative amount of apically extruded debris from severely curved root canals and the preparation time for the novel rotary system TruNatomy (TN; Dentsply Sirona, Charlotte, NC) compared with Reciproc Blue (RCB; VDW Dental, Munich, Germany), HyFlex (HyFlex Controlled Memory [HCM; Coltene/Whaledent, Altstatten, Switzerland] and HyFlex EDM [HEDM, Coltene/Whaledent]), and ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland) rotary systems.

METHODS

One hundred mandibular molar human teeth with severe curvature of the mesiobuccal canal (25°-45°) were included in the present study. The specimens were randomly distributed into 5 balanced groups (n = 20): TN, RCB, HCM, PTN, and HEDM. The amount of extruded debris for each group during instrumentation at body temperature was collected in an Eppendorf tube. After desiccation, the mean debris weights for each group were calculated. The total preparation time for each group was also recorded. Data were statistically analyzed using the Kruskal-Wallis test at a significance level of P < .05.

RESULTS

The HCM and HEDM groups extruded a significantly higher amount of debris than the other tested groups (P < .001). TN extruded the least amount of debris, but it was not significantly different compared with the RCB and PTN groups (P > .05). In terms of preparation time, the TN group did not show any significant difference compared with the other groups.

CONCLUSIONS

All instrumentation systems extruded debris. TN was among the groups that produced the lowest amount of apically extruded debris that is clinically acceptable. The amount of apically extruded debris using the TN system was equal to 2 popular systems and statistically significantly less than 2 other popular systems studied.

Comparison of efficacy of ozonated water, normal saline, and povidone-iodine after surgical removal of impacted mandibular third molars: A cross-sectional study

Background:

Surgical extraction of mandibular third molars is an important and one of the most frequently performed operative procedures in dentistry. There are a variety of postoperative complications that may follow this procedure. These include pain, trismus, infection, dry socket, or alveolar osteitis. Numerous techniques have been used for reducing these morbid conditions. These range from flap designs, suture placement, use of various irrigating solutions, etc.,

Aim:

The present study aimed to compare the effectiveness of three irrigating solutions: Ozonated water, normal saline, and povidone-iodine in reducing postoperative complications following surgical removal of impacted mandibular third molars.

Materials and Methods:

A total of 100 study participants formed the sample size of this study. Study subjects were categorized into three groups: Group I (third molar surgeries using ozonated water), Group II (third molar surgeries with normal saline irrigation), and Group III (third molar surgeries using povidone-iodine irrigation). Parameters studied postoperatively were alveolar osteitis (dry socket), pain, trismus, and infection after a week interval. All data obtained were entered in Microsoft Excel 2007 worksheets and Analysis of Variance (ANOVA) as a statistical tool was employed. A P value of < 0.01 was considered statistically significant.

Results:

It was found that ozonated water provided the best statistically proven results with comparison to normal saline and povidone-iodine in reducing the incidence of alveolar osteitis or dry socket and pain. No statistically significant difference was observed in the incidence of trismus and infection rate among three studied groups.

Conclusion:

Ozonated water is the best irrigating solution when compared to normal saline and povidone-iodine in terms of reduction in pain and dry socket after a 1-week duration.

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) 87Sr/86Sr isotope data from scythian Iron age barrows in Altai, Russia

This paper reports LA-ICP-MS ⁸⁷Sr/⁸⁶Sr isotopic data collected from archaeological human remains uncovered in Manzherok region, Altai Republic, Russian Federation ("Mobility of nomads in central Asia: chronology and ⁸⁷Sr/⁸⁶Sr isotope evidence from the Pazyryk barrows of northern Altai, Russia" [1]. The skeletal remains derive from Scythian barrows dated to 6th - 3rd century BC located at Chultukov Log 1 cemetery. The Chultukov Log cemetery, located approximately 470km south of Novosibirsk, is considered the biggest nomadic burial ground in the Upper Altai and the Sayan Mountains. To enrich the information on prehistoric mobility of ancient nomadic populations in Central Asia, strontium isotopic data were collected using a Nu plasma (II) MC-ICP-MS equipped with ESI NWR193-based laser ablation system from premolar teeth of 8 adult individuals (4 males and 4 females), associated mainly with the Pazyryk culture. Additionally, we report bioavailable strontium data from single Equus caballus specimen (found at Chultukov Log 9 settlement) from Manzherok territory. In this study we have successfully applied and tested new in-depth decontamination protocol for total (<95%) removal of contaminants, necrotic tissue and dental calculus in archaeological materials based on a clinical irrigation procedure with NaOCl and EDTA. Strontium LA-ICP-MS ⁸⁷Sr/⁸⁶Sr isotopic data presented in this paper were obtained from prehistoric human teeth previously decontaminated according to this method. These data will provide valuable resources for isotopic analyses of prehistoric transportation systems in Central Asia, including residential mobility of ancient nomads inhabiting steppe zone, Mongolia and NW China.

Antibiofilm Activity of Three Different Irrigation Techniques: An in Vitro Study

The microbial infection of the endodontic space occurs in a necrotic tooth as a result of dental caries, trauma, periodontal disease, or previous root canal therapy. The disruption of the biofilms and the reduction of the bacterial load inside root canals are crucial for the success of root canal therapy. The aim of this study was to compare, in vitro, the antibiofilm efficacy of a novel passive sonic irrigation (PSI) device with passive ultrasonic irrigation (PUI) and conventional needle irrigation (CNI). Forty-four single-rooted human teeth were inoculated with a culture of E. faecalis for 28 days. The specimens were randomly divided into three groups: PUI, CNI, and PSI (n = 12). The activation protocols were performed using both 17% EDTA and 5.25% NaOCl. Residual bacterial biofilm was taken by means of a canal brush and colony-forming unit (CFU) were counted. The data were analyzed using one-way ANOVA and Games-Howell's post hoc tests. A major reduction in CFU was observed in the PSI and PUI groups, in comparison with the CNI group. No difference was found (p > 0.05) in terms of CFU reduction between PSI and PUI. PSI could be as effective as PUI in the removal of bacterial biofilms from straight root canals.

Efficacy of irrigant activation techniques in removing intracanal smear layer and debris from mature permanent teeth: a systematic review and meta-analysis

AIMS

To establish whether irrigant activation techniques (IATs) result in greater intracanal smear layer and debris removal than conventional needle irrigation (CNI).

METHODOLOGY

Six electronic databases were searched to identify scanning electron microscopy studies evaluating smear layer and/or debris removal following the use of manual dynamic activation (MDA), passive ultrasonic irrigation (PUI), sonic irrigation (SI) or apical negative pressure (ANP) IATs in mature permanent teeth. Meta-analyses were performed for each canal segment (coronal, middle, apical and apical 1 mm) in addition to subgroup analyses for individual IATs with respect to CNI. Outcomes were presented as standardized mean differences (SMD) alongside 95% confidence intervals (95% CI) and chi-squared analysis.

RESULTS

From 252 citations, 16 studies were identified. The meta-analyses demonstrated significant improvements in coronal (SMD: 1.15, 95% CI: 0.72-1.57 / SMD: 0.54, 95% CI: 0.29-0.80), middle (SMD: 1.30, 95% CI: 0.59-2.53 / SMD: 0.8, 95% CI: 0.58-1.13) and apical thirds (SMD: 1.22, 95% CI: 0.83-1.62 / SMD: 1.86, 95% CI: 0.76-2.96) for smear layer and debris removal, respectively. In the apical 1 mm IATs improved cleanliness; however, differences were insignificant (SMD: 1.15, 95% CI: -0.47-2.77). Chi-squared analysis revealed heterogeneity scores of 79.3-92.8% and 0.0-93.5% for smear layer and debris removal, respectively.

CONCLUSIONS

IATs improve intracanal cleanliness across a substantial portion of the canal, and therefore, their use is recommended throughout root canal preparation. However, current data is too heterogeneous to compare and identify superiority of an individual technique highlighting the need to standardize experimental protocols and develop a more representative research model to investigate the in vivo impact of IATs on clinical outcomes and periapical healing following root canal treatment.

Core-Shell Silver Nanoparticles in Endodontic Disinfection Solutions Enable Long-Term Antimicrobial Effect on Oral Biofilms

To achieve effective long-term disinfection of the root canals, we synthesized core-shell silver nanoparticles (AgNPs@SiO₂) and used them to develop two irrigation solutions containing sodium phytate (SP) and ethylene glycol-bis(β-aminoethyl ether)N,N,N',N'-tetraacetic acid (EGTA), respectively. Ex vivo studies with instrumented root canals revealed that the developed irrigation solutions can effectively remove the smear layer from the dentinal surfaces. Further in vitro experiments with single- and multispecies biofilms demonstrated for the first time that AgNPs@SiO₂-based irrigation solutions possess excellent antimicrobial activities for at least 7 days, whereas the bare AgNPs lose the activity almost immediately and do not show any antibacterial activity after 2 days. The long-term antimicrobial activity exhibited by AgNPs@SiO₂ solutions can be attributed to the sustainable availability of soluble silver, even after 7 days. Both solutions showed lower cytotoxicity toward human gingival fibroblasts compared to the conventionally used solution (3% NaOCl and 17% EDTA). Irrigation solutions containing AgNP@SiO₂ may therefore be highly promising for applications needing a long-term antimicrobial effect.