Straight Root Research Articles

Impact of root canal curvature and instrument type on the amount of extruded debris during retreatment.

ObjectivesThe aim of the current study was to assess whether the amount of extruded debris differs for straight and severely curved root canals during retreatment using H-files, R-Endo, Reciproc and ProTaper Universal Retreatment (PTU-R) files. Additionally, the area of residual filling material was evaluated.Materials and MethodsSeverely curved (n = 104) and straight (n = 104) root canals of maxillary molar teeth were prepared with WaveOne Primary file and obturated with gutta-percha and AH Plus sealer. Root canal filling materials were removed with one of the preparation techniques: group 1: H-file; group 2: R-Endo; group 3: Reciproc; group 4: PTU-R (n = 26). The amount of extruded material and the area of the residual filling material was measured. The data were analyzed with 2-way analysis of variance (ANOVA) and 1-way ANOVA at the 0.05 significance level.ResultsExcept for Reciproc group (p > 0.05), PTU-R, R-Endo, and H-file systems extruded significantly more debris in severely curved canals (p < 0.05). Each file system caused more residual filling material in severely curved canals than in straight ones (p < 0.05).ConclusionsAll instruments used in this study caused apical debris extrusion. Root canal curvature had an effect on extruded debris, except for Reciproc system. Clinicians should be aware that the difficult morphology of the severely curved root canals is a factor increasing the amount of extruded debris during the retreatment procedure.

A Comparative Study of the Efficacy of WaveOne and NeoEndo Retreatment File System for the Removal of Gutta Percha from the Root Canal.

Background:Teeth with apical periodontitis that either persisted or developed after initial root canal treatment is most often indicated for retreatment procedure. The present study was conducted to compare the WaveOne and NeoEndo retreatment file system for the removal of gutta-percha from the root canal.Materials and Methods:Fifty extracted mandibular first premolars with single straight roots were divided into two groups, Group I-WaveOne and Group II-NeoEndo. All samples were scanned with cone-beam computed tomography after the root filling and retreatment procedures. The decrease in the volume of filling material after each retreatment protocol was measured.Results:The mean volume of gutta-percha in Group I before retreatment was 5.6 and in Group II was 5.3, after retreatment in Group I was 2.7, and in Group II was 4.2. The mean percentage reduction in Group I was 45.2% and in Group II was 23.8%. The difference was significant (P < 0.05).Conclusion:Both systems failed to completely remove gutta-percha. WaveOne was significantly more effective than the NeoEndo retreatment system.

Removal of Calcium Hydroxide Pastes Containing N-Methyl-2-Pyrrolidone, Local Anaesthesia, Glycerine, and Methylcellulose from Artificial Radicular Grooves: An In-vitro Study.

Objective:To compare the removal of calcium hydroxide (CaOH) pastes containing N-Methyl-2-pyrrolidone (NMP), lidocaine, glycerine, methylcellulose, or water from artificially created grooves.Methods:In this study, 115 human single-rooted maxillary incisors with single and straight root canals were prepared using a rotary file up to size 40/.04 and split longitudinally. A longitudinal groove was created from 2 to 5 mm from the apex and filled with CaOH combined with different vehicles. The specimens were divided among 5 experimental groups according to the vehicle as follows: distilled water, lidocaine, glycerine, methylcellulose, and NMP. The two halves were re-attached, and the canals were flushed with 10 ml of 17% EDTA for 60 seconds. The residual amount of CaOH was scored using a stereomicroscope at 8× magnification. Statistical significance was set at P<0.05.Results:The NMP-based group exhibited significantly less residual medicament compared to the distilled water (P<0.05), while there were no statistically significant differences among the methylcellulose-, lidocaine-, and glycerine-based groups and distilled water (P>0.05).Conclusion:The vehicle is an important factor in the successful removal of CaOH medicament from the root canals. Within the limitations of the present study, the NMP-based CaOH medicament exhibited better removal efficacy than the distilled water. However, the cleaning success of the methylcellulose-, lidocaine-, and glycerine-based groups was similar to that of distilled water.

Root canal retreatment: a retrospective investigation using regression and data mining methods for the prediction of technical quality and periapical healing.

Objectives This study aimed to investigate patterns and risk factors related to the feasibility of achieving technical quality and periapical healing in root canal non-surgical retreatment, using regression and data mining methods.Methodology This retrospective observational study included 321 consecutive patients presenting for root canal retreatment. Patients were treated by graduate students, following standard protocols. Data on medical history, diagnosis, treatment, and follow-up visits variables were collected from physical records and periapical radiographs and transferred to an electronic chart database. Basic statistics were tabulated, and univariate and multivariate analytical methods were used to identify risk factors for technical quality and periapical healing. Decision trees were generated to predict technical quality and periapical healing patterns using the J48 algorithm in the Weka software.Results Technical outcome was satisfactory in 65.20%, and we observed periapical healing in 80.50% of the cases. Several factors were related to technical quality, including severity of root curvature and altered root canal morphology (p<0.05). Follow-up periods had a mean of 4.05 years. Periapical lesion area, tooth type, and apical resorption proved to be significantly associated with retreatment failure (p<0.05). Data mining analysis suggested that apical root resorption might prevent satisfactory technical outcomes even in teeth with straight root canals. Also, large periapical lesions and poor root filling quality in primary endodontic treatment might be related to healing failure.Conclusion Frequent patterns and factors affecting technical outcomes of endodontic retreatment included root canal morphological features and its alterations resulting from primary endodontic treatment. Healing outcomes were mainly associated with the extent of apical periodontitis pathological damages in dental and periapical tissues. To determine treatment predictability, we suggest patterns including clinical and radiographic features of apical periodontitis and technical quality of primary endodontic treatment.

Accuracy and stability of electronic apex locator length measurements in root canals with wide apical foramen: an ex vivo study

The aim of the current study was to determine the accuracy of electronic apex locator (EAL) measurements when using files of different sizes in roots with wide apical foramina while considering a new parameter of stability of EAL reading. Ten teeth with straight roots were subjected to a sequential widening of the apical foramen to 0.6, 0.7, and 0.8 mm. The roots were embedded after each enlargement stage in an alginate mold and subjected to EAL readings. Measurements were done using sequential K-file sizes and the self-adjusting file (SAF). Measurement stability was introduced as a new additional parameter. As the difference between the file size used and the apical diameter of the canal decreases, the results obtained were more accurate and stable. The stability and accuracy of the measurements coincided with each other in a statistically significant manner. Within the limitations of the present ex vivo study, it may be concluded that in straight canals with wide apical foramina of 0.6–0.8 mm, both SS K-files which fit snugly to the walls of apical foramen and the SAF file may offer both accurate and stable EAL measurements.

Apical extrusion of debris produced by the heat treated single-file systems XP-Endo Shaper, Reciproc Blue and ProDesign Logic

Aim: This study evaluated the apical extrusion of debris during root canal preparation produced by the single-file systems XP-Endo Shaper (FKG Dentaire, La Chaux-de-Fonds, Switzerland), Reciproc Blue (VDW GmbH, Munich, Germany), and ProDesign Logic (Easy Equipamentos Odontologicos, Belo Horizonte, MG, Brazil). Methodology: Thirty single straight root canals in mandibular premolar were prepared and randomly assigned to 3 groups (n=10), according to instrument used for root canal preparation: XP-Endo Shaper, Reciproc Blue, or ProDesign Logic. Root canal shaping technique was performed by root segments and the apically extruded debris were collected and quantified using a debris collection setup with Eppendorf tubes and agar gel. Mean values were obtained by subtracting the initial weight of the test apparatus without specimens from its weight after root canal preparation. Then, one-way analysis of variance (ANOVA) followed by Bonferroni post hoc test were applied for comparison of values. The statistical significance level was set at 5%. Results: No significant difference was observed among groups (P>0.05), but all the instruments produced debris extrusion from the apical foramen. Conclusion: The heat treated single-file systems XP-Endo Shaper, Reciproc Blue, and ProDesign Logic produce similar amounts of apically extruded debris during root canal preparation. All single-file systems evaluated promoted apical extrusion of debris.

Solubility and Sealing Ability of Recently Introduced Biocearmic Root-End Filling Materials

Purpose: the current study was conducted for evaluation of solubility and sealing ability of two recently introduced biocearmic root end filling materials (Bio MTA and Total Fill) in comparison to the gold standard Mineral Trioxide Aggregate (MTA).Materials and Methods: Regarding solubility test a total of 15 disc specimens were fabricated from the three tested materials. The discs were then divided randomly into three equal groups (n=5) according to tested root end filling materials (Pro root MTA, Bio MTA, and Total Fill biocearmic). The solubility test was done according to ISO no 6786. The amount of residue weight from each specimen was estimated and expressed as a percent of solubility. While for sealing ability testing, a total number of 15 freshly extracted human mandibular premolars with straight roots, single canal, and fully formed root apices were selected, and the crown was removed and canal was prepared and obturated, then the apical 3 mm of each root was removed. The root-end cavity with 3mm in depth and 1.5mm in width was done using diamond ultrasonic tips. The tested materials were mixed and placed inside the cavities. The specimens were sectioned by isomet for further environmental scanning electron microscopic investigation of sealing ability. Results: In both tests a significant difference was found between the control group (MTA group) and two tested groups (Total Fill group, Bio MTA group) where (p < 0.001).Moreover, the Bio MTA group and Total Fill group showed a lower solubility % and higher sealing ability in comparison to Pro root MTA group and this was explained in term of negative correlation between the solubility %and sealing ability. Conclusions: Total Fill and Bio MTA exhibits less solubility % and better sealing ability compared to the Pro root MTA. Based on improved sealing ability of both Total Fill and Bio MTA material, they could be considered as a good choice for the replacement of conventional MTA as root end filling materials

ANTIMICROBIAL EFFECTIVENESS OF PHOTON-İNDUCED PHOTOACOUSTIC STREAMING, PHOTOACTIVATED DISINFECTION AND SODIUM HYPOCHLORITE IRRIGATION IN INFECTED ROOT CANALS

Aim: This study aimed to evaluate the antibacterial and antifungal effects of different disinfection methods for infected root canals with Enterococcus faecalis or Candida albicans in vitro. Material and Methods: Hundred extracted, single-rooted human teeth with straight root canals were selected. After chemo-mechanical preparation of the root canals, except of those in the negative control group, contamination was performed using Enterococcus faecalis or Candida albicans for 7 days. The infected teeth were divided into three subgroups (n = 15) according to the disinfection method applied: photo‑activated disinfection, photon-induced photoacoustic streaming and 2.5% sodium hypochlorite irrigation. Microbial samples were collected from the root canals before and after disinfection. Hundred Colony forming units were counted, and data were statistically analysed. Results: All experimental groups showed significant reduction of Enterococcus faecalis and Candida albicans. Photon-induced photoacoustic streaming and sodium hypochlorite irrigation had similar antimicrobial effect, which was higher than photo‑activated disinfection for both microorganisms (p < 0.05). Conclusion: None of the testing methods for root canal disinfection was able to achieve complete elimination of microorganisms. However, the results of this study state that photon-induced photoacoustic streaming, photo‑activated disinfection and 2.5% NaOCl has significant antimicrobial effect against Enterococcus faecalis and Candida albicans biofilms in root canals. Key words: Candida albicans, Enterococcus faecalis, Photodynamic Therapy, Root Canal, Sodium Hypochlorite Foton ile İndüklenen Fotoakustik Dalgalanma Tekniği, Işıkla Aktive Edilen Dezenfeksiyon ve Sodyum Hipokloritin Enfekte Kök Kanallarındaki Antimikrobiyal Etkileri Öz Amaç: Bu çalışmada, Enterococcus faecalis veya Candida albicans ile enfekte edilmiş kök kanallarında farklı dezenfeksiyon yöntemlerinin antibakteriyel ve antifungal etkilerinin in vitro olarak incelenmesi amaçlanmıştır. Gereç ve yöntem: Çalışmada yüz adet çekilmiş, tek köklü, düz kanallı diş kullanıldı. Kök kanallarının kemo-mekanik preparasyonunun ardından, negatif kontrol grubu haricindeki dişler 7 gün boyunca Enterococcus faecalis veya Candida albicans ile enfekte edildi. Enfekte edilen dişler uygulanan dezenfeksiyon yöntemine göre ışıkla aktive edilen dezenfeksiyon, fotonla indüklenen fotoakustik dalgalanma tekniği veya %2.5 sodyum hipoklorit irigasyonu uygulanmak üzere üç alt gruba (n = 15) ayrıldı. Dezenfeksiyon öncesi ve sonrasında kök kanallarından mikrobiyal örnekler alındı. Koloni oluşturan birimler sayıldı ve veriler istatistiksel olarak analiz edildi. Bulgular: Tüm deney gruplarında, Enterococcus faecalis ve Candida albicans mikroorganizmalarında önemli ölçüde azalma gözlendi. Fotonla indüklenen fotoakustik dalgalanma tekniği ve sodyum hipoklorit irigasyonu benzer antimikrobiyal etkiye sahip bulunurken (p>0.05), her iki grubun gösterdiği antimikrobiyal etki ışıkla aktive edilen dezenfeksiyondan iki mikrooganizma türü için de daha yüksek bulundu (p<0.05). Sonuç: Uygulanan dezenfeksiyon yöntemlerinin hiçbiri ile mikroorganizmaların tümünün elimine edilmesi mümkün olmadı. Bununla birlikte, bu çalışmanın sonuçları; foton ile indüklenen fotoakustik dalgalanma tekniği, ışıkla aktive edilen dezenfeksiyon ve %2.5 sodyum hipokloritin kök kanallarındaki Enterococcus faecalis ve Candida albicans biofilmlerinde önemli ölçüde antimikrobiyal etkinliğe sahip olduğunu göstermektedir. Anahtar Kelimeler: Candida albicans, Enterococcus faecalis, Fotodinamik Terapi, Kök Kanalı, Sodyum Hipoklorit

The profiles and tensile strength on straight roots of plants withstand transient tensile injured after self-repair

Plants roots are severely injured during the process of withstanding transient tensile, and the injured roots can self-repair. We investigated the change law of the growth characteristics and tensile strength on straight roots withstand transient tensile injured after self-repair. The survival rate of two kinds of injured plants roots was between 60 and 89%. The test roots after self-repaired, the tensile strength reduction rate of Hippophae rhamnoides L. roots was greater than that of Salix psammophila roots. The tensile force was positively related to the power function of root diameter, the tensile strength was negatively related to the root diameter in a power function. The tensile strength of straight roots under small injured force showed an increasing trend, but the straight roots under the large injured force showed the opposite result. The survival rate of rough roots was greater than that of fine roots. The large injured force was not conducive to the repair and force again of the straight roots of two kinds of plants. The reduction rate of tensile strength after repaired with small force was less than that of large force. The self-repair ability of fine roots was weaker than that of rough roots.

The Efficacy of Rotary, Reciprocating, and Combined Non-Surgical Endodontic Retreatment Techniques in Removing a Carrier-Based Root Canal Filling Material from Straight Root Canal Systems: A Micro-Computed Tomography Analysis.

The aim of this study is to analyze and compare the efficacy of three non-surgical endodontic retreatment techniques in removing a carrier-based root canal filling material from straight root canal systems. The study was performed on 99 single-rooted extracted teeth using the ProTaper Gold endodontic rotary system up to the F2 file (Dentsply Maillefer, Baillagues, Switzerland), which were sealed with GuttaCore (Dentsply Maillefer, Ballaigues, Switzerland) and AH plus epoxy resin sealer (Dentsply DeTrey, Konstanz, Germany) and randomly assigned to the following non-surgical retreatment techniques: ProTaper Retreatment endodontic rotary instruments (D1–D3 files, Dentsply Maillefer, Ballaigues, Switzerland; n = 33, PTR), Reciproc Blue endodontic reciprocating instrument (R50, VDW, Munich, Germany; n = 33, RCB50), and a combined root canal retreatment technique between Gates-Glidden drills (sizes #3 and #2, Dentsply Maillefer, Ballaigues, Switzerland) and Hedstrom files (file size 35, 30, and 25, Dentsply Maillefer, Ballaigues, Switzerland; n = 33; H-GG). All of the teeth were submitted twice to a micro-computed tomography (micro-CT) scan, before and after non-surgical endodontic retreatment procedures. The volume of root canal filling material (mm3), volume of remaining root canal filling material (mm3), non-surgical endodontic retreatment working time (min), proportion of remaining root canal filling material (%), and efficacy of root canal filling material removal between the non-surgical endodontic retreatment techniques were analyzed using ANOVA one-way statistical analysis. Statistically significant differences were observed between the proportions of remaining root canal filling material of PTR and H-GG (p = 0.018), between the non-surgical endodontic retreatment working times (min; p < 0.001), and between the efficacies of root canal filling material removal by the non-surgical endodontic retreatment techniques (p = 0.009). However, the non-surgical endodontic retreatment systems allow for similar carrier-based root canal filling material removal.

The effect of ultrasonic file sizes on smear layer removal in passive ultrasonic irrigation

Objectives: The aim of this study was to evaluate the efficacy of CK files as an ultrasonic instrument, and to determine most efficient file size for smear layer removal. Materials and Methods: Thirty-six extracted human mandibular premolars with single, straight root canals and mature apices were mechanically prepared and randomly divided into three groups. Group 1 (Control) underwent conventional needle irrigation, Group 2 (CKS) underwent passive ultrasonic irrigation with a #20 CK file, and Group 3 (CKL) underwent passive ultrasonic irrigation with a #30 CK file. After preparation and irrigation, all teeth were dried and split with a chisel to obtain the mesial and distal half of their roots. Each sample was evaluated using a scanning electron microscope, and data were analyzed using the Kruskal-Wallis and Mann-Whitney rank sum tests (p&lt;0.05). Results: The CKS group showed less debris in the apical third than the other groups (p&lt;0.05). In this section, no significant difference was observed among the other groups. And, there was no significant difference among any groups for the middle third section. Conclusion: This study showed that PUI with #20 CK file removed more smear layer compared to using #30 CK file at the apical third of the root canal.

CaСl2 Salt Signaling in Primary Root Architecture and Lateral Root Emergence in Arabidopsis thaliana

Plant root architecture modulates during developmental stages and adjusts with the environmental condition. The cytosolic calcium which is a ubiquitous secondary messenger in all eukaryotes strongly affects the root system in Arabidopsis thaliana (L.) Heynh. We proposed that calcium chloride gradients affect PIN2 expression, which in term modulates root architecture and lateral root emergence. In the present study, the root development of PIN2 overexpressing lines of A. thaliana were investigated on different CaCl2 concentrations. This study found that the abundance of PIN2 protein has a direct effect on the root curvature with respect to CaCl2 gradient. In the presence of low concentration of CaCl2, PIN2 protein is stabilized and its subsequent accumulation lead to straight root architecture. However, as the CaCl2 concentration were increased, PIN2 protein destabilized and subsequently degraded which in turn showed a wavy root phenotype. On the other hand, different concentrations of CaCl2 did not show any effect on PIN2 gene at transcript level.

Comparison of Obturation Removal Efficiency from Straight Root Canals with ProTaper Gold or Reciproc Blue: A Micro-Computed Tomography Study.

Background: The objective was to evaluate the efficiency of ProTaper Gold (PTG) and Reciproc Blue (RB) NiTi files in obturation material removal from straight root canals assessed by micro-computed tomography. Methods: Fifty-two anterior human teeth were shaped with a PTG rotary system until F2 (25/.08). Specimens were obturated with a continuous wave of condensation technique. For retreatment, specimens were randomly distributed in two experimental groups: PTG group (F4 file) and RB (R40 file). Micro-CT scans were performed before and after retreatment procedures. The percentage of the remaining obturation material compared to the original volume was calculated, as well as the retreatment time. The presence of separated files was recorded. A descriptive analysis was carried out, and nonparametric tests were employed. Results: The mean percentages of remaining obturation material in the PTG group and the RB group were 4.14 ± 4.30% and 4.18 ± 4.29%, respectively. The mean retreatment times for the PTG and RB groups were 144 ± 51 and 163 ± 88 s, respectively. There were no statistically significant differences, neither in removal efficiency (p > 0.05) nor in retreatment time (p > 0.05), between the two groups. The coronal and middle thirds presented significantly more remaining obturation material than the apical third (p < 0.05). No file separation occurred. Conclusions: ProTaper Gold and Reciproc Blue present with comparable efficiency in removing the obturation material, with a similar mean retreatment time.

The effects of alternate irrigation of root canals with chelating agents and sodium hypochlorite on the effectiveness of smear layer removal.

After the mechanical preparation of a root canal, the canal walls are covered with a smear layer. In order to deeply clean the dentinal tubules, removal of the smear layer is recommended. There is no consensus on the length of time of rinsing with chelating agents or irrigation with alternating chelating agents and sodium hypochlorite (NaOCl). The aim of the study was to evaluate the effectiveness of smear layer removal using 4 irrigation protocols. We prepared 42 straight root canals to size ISO40/04 and assigned them into 4 study groups (n = 10) and a control group (n = 2). The root canals were irrigated as follows: in the control group, 180 s with 5.25% NaOCl; in group 1, 60 s with 40% citric acid (CA) and 120 s with NaOCl; in group 2, 120 s with CA and 120 s with NaOCl; in group 3, 30 s CA, 30 s with NaOCl, 30 s CA and 120 s with NaOCl; and in group 4, 60 s with CA, 30 s with NaOCl, 60 s with CA, and 120 s with NaOCl. The roots were split longitudinally and the root canals were observed under ×200-500 magnification. The root canal walls were analyzed in areas 2 mm, 6 mm and 10 mm from the apex. In the apical and medial sections, the best effects were achieved in groups 3 and 4. In coronal sections, no significant differences between experimental groups were found. Within the limitations of this study, it can be concluded that irrigation with alternating NaOCl and CA was the most effective at smear layer removal, regardless of the irrigation time.

Evaluation of Cleaning Efficacy of S-One and WaveOne File Systems Using Scanning Electron Microscopy Analysis: An In Vitro Study

The aim of this study is to compare the canal cleaning ability of S-One file (AF BLUE) system with WaveOne Gold single file system, using scanning electron microscopy (SEM). In the present study, 40 freshly extracted permanent mandibular premolars with a single-root canal and straight roots were selected. The teeth were randomly divided into three groups. The canals were prepared by crown-down technique. Buccolingual sectioning of the samples were done followed by SEM evaluation. Data were statistically analyzed using Kruskal-Wallis test. The statistical significance level was set at p value <0.05. The analysis of the results demonstrated that WaveOne presented higher cleaning capacity of root canals with a statistically significant difference, when compared to S-One file system (p value < 0.05). Both the file systems showed significant cleaning efficacy in the coronal and middle-thirds of the root canals when compared to the apical thirds. Also, the WaveOne showed better results than S-One (AF BLUE), and the results were statistically significant. With the limitation of the study, the cleaning ability of rotary file system is high in coronal and middle-third followed by apical third. In this study, the WaveOne showed better results than S-One (AF BLUE), and the results were statistically significant. The aggressive cutting of dentin during canal preparation is less in WaveOne file than S-One file system. The cleaning efficiency is good in reciprocating file system (WaveOne) than continuous rotary file system (S-One).

Influence of obturation technique on penetration depth and adaptation of a bioceramic root canal sealer.

Aim:Evaluation of the impact of three different obturation techniques on the penetration depth and adaptation of a bioceramic root canal sealer(BioRoot RCS) to root dentin using scanning electron microscope and confocal laser scanning microscope.Materials and Methods:Recently extracted ninety mandibular premolar teeth of similar dimensions (±0.2 mm) with single canals and straight roots were segregated into three experimental groups (n = 30 each) based on the method of obturation used, i.e., lateral compaction technique, warm vertical compaction technique, and injectable thermoplasticized technique. After obturation, half of the root samples (n = 15) in each group were sectioned horizontally by hard tissue microtome at 3, 6, and 9 mm, respectively, from root apex for measuring sealer penetration depth with a confocal laser scanning microscope. Longitudinal sections of the samples (n = 15) were used for measuring the adaptation of sealers to radicular dentin using a scanning electron microscope.Statistical Analysis:Intergroup comparison of sealer penetration depth and adaptation to root dentin was analyzed using one-way ANOVA, and pairwise comparisons were made using Tukey's post hoc test.Results:Warm vertical condensation technique showed deeper root dentin penetration of the sealer. Better adaptation of the sealer to apical root dentin with minimal voids (P ≤ 0.05) was achieved with warm vertical condensation in comparison to the injectable gutta-percha method and lateral condensation obturating techniques.Conclusion:At all three root levels (coronal, middle, and apical), warm vertical condensation technique exhibited more sealer penetration with minimum gaps, whereas lateral condensation technique exhibited more gaps and less sealer penetration.

In Vitro comparison of the microbial leakage of obturation systems: Epiphany with resilon, guttaflow, and ah plus with gutta percha.

To compare the microbial leakage of three root canal filling materials: AH Plus with Gutta-percha, Epiphany with Resilon, and Guttaflow using Enterococcus faecalis as the bacterial marker. In total, 30 caries free, human maxillary incisors with straight roots were used. The teeth were de-coronated with a diamond disc and the length was standardized for all specimens. Access opening was done through the coronal portion and the working length was determined. All the teeth were prepared to a standardized size apically and coronally. The teeth were then randomly divided into three experimental groups each. After obturation of the root canals, the outer surfaces of the teeth were coated with two layers of nail enamel except the apical 2 mm. The teeth were then subjected for bacterial leakage test using E. faecalis as a bacterial marker in dual chamber bacterial leakage model for a period of 30 days. Chi-square test. Results showed that Resilon/Epiphany (Group-2) demonstrated less leakage and Gutta-percha/AH Plus (Group-1) showed maximum leakage with the statistically significant difference between the two (P < 0.05). Guttaflow (Group-3) also showed less leakage than Gutta-percha/AH Plus (Group-1) with the statistically significant difference between the two (P < 0.05). There was no statistically significant difference between Resilon/Epiphany (Group-2) and Guttaflow (Group-3). Resilon/Epiphany and Guttaflow groups demonstrated less microbial leakage than Gutta-percha/AH Plus group.

Incidences of Root Microcracks Caused by Hand and Rotary File System at Different Lengths

OBJECTIVES: The present research was conducted to assess incidences of root microcracks caused by hand and rotary file system at different lengths MATERIAL AND METHODS: This in-vitro study was undertaken to assess incidence of root microcracks caused by hand and rotary file system at different lengths In total, 100 the mandibular premolar with straight roots determined with intact, fully formed apices were taken. Samples were randomly distributed into 5 groups based on the file system used: a) Group A: Control, b) Group B: Reciproc, c) Group C: WaveOne, d) Group D: One Shape and e) Group E: ProTaper. Pearson Chi-square test was used to determine the differences between groups. The dentinal defects were expressed as percentage of samples with microcracks in each group. Level of statistical significance was set at p-value less than 0.05. RESULTS: The chi square test was used to compare the Distribution of the number of teeth in which cracks were observed on the horizontal sections. It was found to be significant with group ProTaper showing maximum cracks at 3,6,9 mm level as compared to other file systemCONCLUSION: Nickel-titanium instruments causes cracks on the apical root surface or in the root canal wall. ProTaper causes maximum dentinal cracks as compared to other file systems

Debris Apically Extruded by Two Reciprocating Systems: A Comparative Quantitative Study.

Objective The objective of this study was to quantify the amount of debris apically extruded after instrumentation with two reciprocating systems. Materials and Methods Forty-two single-rooted mandibular premolars with only one straight root canal and apical diameter compatible with a no. 15 K-file were randomly divided into two groups ( n = 21) according to the instrument used: ProDesign R (Easy Equipamentos; Belo Horizonte, Minas Gerais, Brazil) and Reciproc Blue (VDW; Munich, Germany). Dry Eppendorf tubes were weighed three consecutive times for the initial mean weight. A silicone stopper was then fitted into the mouth of the tube. Each tooth was inserted through the stopper up to the cementoenamel junction and instrumented with one of the two systems to the predetermined working length (18 mm). The root canals were instrumented per root thirds. At each instrumented root third, the canal was irrigated with 3 mL of double-distilled water, followed by patency control. Each stopper was then separated from the tube and tubes were incubated at 70°C for 5 days. Tubes were again weighed, and the amount of extruded debris was calculated by subtracting the initial mean weight from the final mean weight. Statistical Analysis Results were analyzed using the Mann–Whitney test at a 5% significance level. Results No significant difference was observed in debris extrusion between the ProDesign R and Reciproc Blue systems ( p = 0.7557). Conclusions The two reciprocating systems tested produced similar amounts of postinstrumentation apically extruded debris.

The differences in root canal smear layer removal between 6,25% pineapple (Ananas comocus L. Merr.) peel extract and 17% Ethylene diamine tetra-acetic acid

Background: The smear layer is attached to dentine and occludes the orifice and, consequently, must be removed in order to improve the success of inroot canal treatment. The ideal irrigation material removes both the organic and inorganic smear layers. Ethylene diamine tetra-acetic acid (EDTA) is one of the most commonly used root canal irrigation materials, but removes only inorganic smear layer. To overcome this problem, Pineapple (Ananas comosus L. Merr.) peel extract, which contains saponins, bromelain, polyphenol and flavonoid, is used during root canal irrigation. Purpose: The study aimed to analyze the difference in smear layer removal between the use of 6.25% pineapple peel extract and 17% EDTA. Methods: 27 samples of mandibular premolar teeth with straight root canals were divided randomly into three groups (n = 9) and subsequently prepared using protaper. Irrigation was performed on the control group (aquadest), group I (17% EDTA) and group II (6.25% pineapple peel extract). The samples were dried, temporarily compressed and cut horizontally from the apical to the coronal. Samples were fixed with holder before the smear layer was observed through a scanning electron microscope (SEM). The resulting data was analyzed by means of an ANOVA test. Results: The highest score of root canal hygiene was recorded by group II, followed by group I and, finally, the control group. There were significant differences between the groups (p&lt; 0.000). Conclusion: 6.25% pineapple peel extract produces a higher smear layer removal effect than 17%EDTA on the apical 1/3 of the root canal.