Gutta-percha Points Research Articles

Effect of ionizing radiation on the microstructure and physical properties of endodontic gutta-percha points.

Patients undergoing radiotherapy for head or neck cancer often require root canal treatments, which can be compromised by the effects of radiation. This investigation aimed to determine whether ionizing radiation (IR), in doses similar to those used in conventional therapy, affects the surface and physicomechanical properties of various brands of endodontic gutta-percha points (EGPs). One hundred and twenty-three EGPs from three brands (Meta-Biomed, Dentsply, and Hygenic) were divided into groups and either exposed or not exposed to IR at a total dose of 50 Gy, divided into 25 fractions. Tensile strength and microhardness tests were performed on all EGPs. Scanning electron microscopy was utilized to identify possible microstructural surface changes due to IR exposure. The proportion of organic to inorganic components in each brand was also determined. Exposure to IR resulted in significant changes only in the EGPs from the Meta-Biomed brand, including a notable decrease in tensile strength and an increase in microhardness. Furthermore, the surface microstructure of these EGPs displayed dark lines and striations over a large area, with some lines deeply embedded in the center and cavities of variable depths and extensions observed, leading to irregular and non-smooth surfaces. This brand had the highest proportion of organic components. The physicomechanical properties and surface microstructure of Meta-Biomed brand EGPs were significantly affected by IR at doses used in conventional therapy for head or neck cancer, while the other brands were less affected or unaffected.

Degree of Contamination of Gutta-Percha Points by Staphylococcus aureus (MRSA/MSSA) Strains.

We performed an in vitro analysis of the contamination of GP points, regarding the strains of Methicillin-resistant (MRSA) and Methicillin-sensitive (MSSA) Staphylococcus aureus, using classical microbiology methods and molecular biology techniques. Gutta-Percha points of two different brands from opened packages (already in use for 1 month) were collected for analysis. The assessment involved incubating the GP points in Brain Heart Infusion (BHI) medium to detect microbial growth. Growing microorganisms were plated on a selective and differential chromogenic medium for MRSA/MSSA strains, and the identification of isolates was confirmed by Polymerase Chain Reaction (PCR). In the case of microbial growth, the GP point was submitted to a disinfection protocol. From the 315 collected GP points, only 6 (1.9%) resulted in being positive for microbial growth. After confirmation by PCR, only one sample of the six GP points was contaminated by MRSA, and the remaining five were MSSA-contaminated. The disinfection protocol was effective in all contaminated GP points. The Gutta-Percha points from opened pre-sterilized packages showed a very low degree of contamination by MRSA/MSSA. However, the detection of MSSA and MRSA strains raises concerns about potential contamination in dental clinic environments, and this risk cannot be considered negligible.

Optical microscopy evaluation of root canal filling removal by beginner operators in posterior teeth.

This study analyzed the effectiveness of root canal filling removal in lower molars performed by beginner operators using optical microscopy. A total of 55 mandibular first and second molars with mesial roots exhibiting an average curvature of 10-20° were selected based on preoperative radiographs. Instrumentation was done with ProTaper Gold (Dentsply Sirona) up to F2 (25/.08), using 2ml of 2.5% NaOCl irrigation solution after each file. Root canal obturation was performed using gutta-percha points with cold lateral condensation and Sealapex (Kerr Dental). Coronal fillings were made with composite resin and stored in distilled water for two years. Removal of the root canal fillings was performed with AF Retreatment Rotary (AFRR) and AF Blue R3 (AFBR3) (Fanta Dental Materials) under reciprocating motion with 2.5% NaOCl irrigation. Cross-sections of the coronal, middle, and apical thirds were analyzed at 40x magnification using a STEINDORFF POL microscope with a digital camera. Image analysis was conducted using Image J software, version 1.54, to determine the efficiency of root canal filling removal by percentage. Statistical analysis via one-way ANOVA revealed significant differences between distal and mesial roots (P < 0.05). Specifically, for mesial roots, the removal efficiency was 70.65% in the coronal third, 54.66% in the middle third, and 21.32% in the apical third. Significant difficulties were noted due to fractured files, calcifications, and debris accumulation in the isthmuses. The study concluded that the protocol using Fanta files demonstrated significant differences in removal efficiency correlated with root curvature, compounded by the inexperience of beginner operators. The findings highlight the challenges faced by novice practitioners in achieving effective root canal filling removal.

Size accuracy of the greater taper gutta-percha points – preliminary report

Size accuracy of the greater taper gutta-percha points – preliminary report

Comparative Analysis of Interfacial Adaptation and Depth Penetration of Recent HiFlow versus Regular Bioceramic Sealers in Conjunction with BC Gutta-Percha Points Using Two Different Obturation Techniques-A Preliminary Report of an Ex Vivo Study.

This study aimed to assess the adaptability and penetration depth capacity of recent bioceramic systems, including regular EndoSequence (BC) versus HiFlow (BCH) sealers in the presence of BC points. A total of 54 single-rooted teeth were instrumented and obturated with either the cold or warm compaction technique (n = 9), using either BC, BCH, or AH Plus (AHP) combined with BC points. The adaptation, film thickness, and gaps/voids were evaluated by scanning electron microscopy. The sealer/dentin interface was evaluated by Raman spectroscopy, and depth penetration was evaluated by a confocal laser scanning microscope. According to the normality test, the data were statistically analyzed by ANOVA or Kruskal-Wallis and Mann-Whitney U tests at p < 0.05. BCH sealer showed the significantly thinnest film with the greatest flow (p > 0.001), with further improvement when subjected to the warm compaction technique. Moreover, it exhibited close adaptation with deep penetration into radicular dentin, forming a tag-like structure. The Raman spectra also indicated close contact with the dentin surface. The use of BC sealer with BC points exhibited homogenous, single-unit obturation, either with a cold or warm technique. Furthermore, the use of the warm compaction technique with BCH sealer achieved a gap-free interface associated with tag-like structures, which exhibit the monoblock phenomenon.

Comparative Analysis of the Efficacy of Various Retreatment File Systems in the Removal of Gutta-Percha in Retreatment Cases and Time Taken During the Procedure: An In Vitro Cone Beam CT Study.

Background Removing gutta-percha manually can be a challenging task, especially when addressing densely packed root-filling material, particularly in cases where resin-based sealers are employed for obturation. The use of nickel-titanium (NiTi) rotary instruments not only effectively shapes the root canal but also efficiently removes the endodontic filling from the curved canal during retreatment. Hence, incorporating rotary NiTi instruments in retreatment cases can alleviate fatigue for both patients and operators. Objectives This study aims to compare the efficacy of Neo-Endo retreatment files, R-Endo retreatment files, and K and H files in the removal of endodontic filling material. Additionally, the remnants of gutta-percha in root canals are evaluated using cone beam computed tomography (CBCT). Materials and methods A total of 60 extracted first maxillary molar teeth were selected for this study. Canal preparation was conducted using the step-back method up to an apical size of 40 K-file. The obturation process involved the use of gutta-percha points and AH Plus sealer in a lateral compaction technique. Post-operative CBCT scans were taken. The samples were randomly divided according to the retreatment files used: group I included Neo-Endo retreatment files, group II included R-Endo retreatment files, and group III included conventional K-files and Hedstroem files (H-Files). The retreatment procedure was considered complete when the last instrument easily reached the working-length range and was physically clean. A stopwatch was used to record the time taken by each file to remove the obturating material. T1 represented the total time (including irrigation and change of file) required to reach the apex, while T2 indicated the complete removal of materials from the canal with the last instrument. The overall time recorded (TT) was calculated as T1 + T2. The removal process was analyzed with CBCT scans. Results The Neo-Endo retreatment files removed the filling materials better and more quickly than the other files. Conclusions Despite the presence of residual filling material in all samples, the Neo-Endo retreatment files left the least amount of residual filling material and achieved the shortest completion time.

Comparative Evaluation of the Efficacy of Different Ni-Ti Rotary Instruments in Removal of Gutta-Percha During Root Canal Retreatment: An in vitro Study

Aim: An assessment and comparison of three retreatment files was conducted to determine their effectiveness in the retrieval of gutta-percha. Materials and Method: In the investigation, 60 extracted single-rooted human teeth having straight canals and complete apices were used. The ProTaper Universal file system was used to prepare teeth and obturated using gutta-percha with sealant AH Plus utilizing down pack and backfill obturation technique. Removal was performed with ProTaper, D-RaCe files, MTwo, and R-Endo retreatment files. Using a stopwatch, the time needed to take out the GP was also calculated in seconds. We used ANOVA along with the post hoc Tukey’s test to analyze the quantity of obturating material in apical, middle, and coronal third following decoronation and longitudinal splitting. Results: The average percentage of gutta-percha points removed across root levels varied significantly among the ProTaper, D-RaCe MTwo, and R-Endo groups. With the exception of the ProTaper group, when the middle level displayed the most removal, the coronal level showed much higher removal than the mid-root level, while the apical level often exhibited the highest removal. Conclusion: ProTaper retreatment files outperformed MTwo, D-RaCe, and R-Endo among the four groups in terms of removing root canal filling material. However, none of the experimental groups removed gutta-percha completely from root canals.

Cleaning Efficiency of Different Irrigation Techniques in Simulated Severely Curved Complex Root Canal Systems

IntroductionTo compare the biofilm-mimicking hydrogel removal efficiency of laser-activated irrigation (LAI) with five other irrigation techniques in simulated curved root canals with lateral canals. MethodsThree-dimensional–printed root canal models (60°-curvature, radius 5 mm; dimension 25/.06) with a total length of 20 mm and lateral canals in all directions at 2, 5, and 8 mm (diameter 0.2 mm) from the apex were filled with a colored biofilm-mimicking hydrogel. The following protocols (each 3 × 20 seconds continuous irrigation with distilled water 3 ml/20 seconds; n = 20) were carried out: conventional needle irrigation; manual agitation ([MA], gutta-percha point 25/.06); EndoActivator (=sonically-activated irrigation EndoActivator, 25/.04); EDDY (=sonically-activated irrigation EDDY [SAI-E]; 25/.04); ultrasonically-activated irrigation and LAI (Erbium-doped Yttrium Aluminum Garnet laser; P400FL tip at canal entrance; 25 pps, 50 mJ, 300 μs). Standardized photos were taken with a microscope and the removal of the hydrogel was determined as a percentage for the entire system, the main canal and the lateral canals. Statistical analysis was performed using analysis of variance and Scheffé test (P = .05). ResultsLAI (89.3% ± 5.9%) showed the greatest hydrogel removal followed by SAI-E (65.5% ± 3.3%) and ultrasonically-activated irrigation (59.1% ± 4.7%), with significant differences between these groups (P < .05). Needle irrigation, MA, and sonically-activated irrigation EndoActivator performed equally (P > .05) and obtained the significantly lowest values (P < .05). LAI and SAI-E showed the significantly best hydrogel removal from the main canal (P < .05). At all three levels, LAI removed significantly more hydrogel from the lateral canals than all other techniques (P < .05). ConclusionsLAI was superior to other techniques in both the entire system and the lateral canals in removing the hydrogel. SAI-E achieved comparable results in the main canal.

Evaluation of the standardisation of gutta-percha points

1. Salles AA, Cord CB, Sonnemann TS, at al. Comparative analysis of the diameter of MTwo® system gutta-percha points in relation to their corresponding instruments. RSBO (Online). 2013;10(1):49–55. Google Scholar

Comparative SEM study of the marginal adaptation of MTA and Biodentine after apical resection (in vitro study)

Successful periapical surgery requires appropriate root resection, preparation, and adequate sealing. The aim of the present study was to assess the marginal adaptation of MTA and Biodentine after apical resection with an Er:YAG laser and a diamond turbine bur using a scanning electron microscope (SEM). The crown part of forty-eight extracted single-root human teeth was removed, and the root canal length of 15mm was standardized. The root canals were prepared using rotary Ni-Ti Revo-S files up to an apical stop - AS40 and filled with MTA Fillapex and gutta-percha points (cold lateral condensation). The teeth are divided into 2 main groups: group 1 (n=24) after apical resection with a turbine bur, ultrasonic preparation of the retrograde cavity at 3mm depth and retrograde obturation with Biodentine and MTA; group 2 (n=24) after apical resection with an Er:YAG laser, ultrasonic preparation of the retrograde cavity at a depth of 3mm and retrograde obturation with MTA and Biodentine. A SEM was used for assessment of the marginal adaptation of the material to the root dentin. The data was entered into and analyzed with IBM SPSS Statistics 22.0. In the group with apical resection with a turbine bur, a statistically significant difference in the gap size between the material and dentin was found in both materials we studied (MTA and Biodentine). The higher mean value was in MTA (1.72µm), in Biodentine it was 1.08µm. In the group with apical resection with Er:YAG laser, no statistically significant difference in the gap size between the material and dentin was found in both studied materials: MTA - 1.88µm, Biodentine - 1.32µm. In the present study, MTA and Biodentine showed good sealing capabilities after apical resection. Biodentine displayed better marginal adaptation when resecting the root tip using a turbine bur. The Er:YAG laser-assisted apical resection shows sealing of the open dentinal tubules around the resected root surface.

Canal pretreatment using cold atmospheric argon plasma, chitosan and Chlorine p6 activated by photodynamic therapy with EDTA as a final irrigant on the pushout bond strength of fiber post

AimsTo evaluate the effect of contemporary root canal irrigants i.e., Cold atmospheric argon plasma (CAAP), Chlorine p6 (Clp6), and chitosan on the push-out bond strength (PBS) of glass fiber post (GFP) and marten hardness (MH) of root canal dentin compared to NaOCl+EDTA. Materials and methodsThe anatomic crown of sixty human mandibular premolars was removed by transversal section till cement-enamel junction (CEJ). Root canals were prepared and canals were dried and obturated using gutta-percha points and AH plus sealer. Post space was prepared and specimens were arbitrarily divided into four groups based on the post-space irrigation. (n = 15) Group 1: 5.25% NaOCl + 17% EDTA, Group 2: CAAP + 17% EDTA, Group 3: Chitosan + 17% EDTA and Group 4: Clp6 + 17% EDTA. For MH evaluation five samples from each disinfected group were taken and MH was assessed with the help of an ultra microhardness tester. GFP was cemented using self-etch dual cure cement on the remaining 10 samples from each group. Samples were vertically planted in acrylic resin blocks 1 mm thick slices were subjected to push-out testing and failure mode analysis using a universal testing machine and Stereomicroscope. ANOVA and Tukey multiple comparison tests were used to compare the means of bond integrity attained (p = 0.05). ResultsThe maximum values of PBS and MH were displayed in group 1 (5.25% NaOCl + 17% EDTA) specimens. However, group 3 exhibited the minimum values of bond strength and MH scores. Intergroup comparison analysis revealed that group 2, group 3, and group 4 displayed comparable outcomes of PBS and MH (p > 0.05). The cervical and middle third of group 1 specimens displayed a cohesive type of failure. However, the apical section of group 1 and other tested groups exhibited the adhesive type of failure. ConclusionCanal irrigation with 5.25% NaOCl and 17% EDTA appears to be better in terms of improving the bond integrity of fiber posts with no compromise in MH of the dentin as compared to the contemporary irrigant used.

Effective management of mandibular second premolar with root anomalies

The enigma of successful treatment of mandibular second premolars with taurodontism has been explored for very long due to its rarity of occurrence. This case report aimed to enumerate the successful nonsurgical endodontic management of left mandibular second premolar #35 with three roots and taurodontism. A 34-year-old Saudi male patient with a noncontributory medical history was referred from the prosthodontic department for nonsurgical root canal treatment of tooth #35. Clinical examination revealed rotated clinical crown with caries related to tooth #35. Pulp sensibility cold test of the tooth showed no response, with the absence of pain on percussion and/or visible pocket depth. Radiographic examination showed long and deep pulp chamber and rotated and curved roots with broken apical lamina dura. The tooth was diagnosed with necrotic pulp and asymptomatic apical periodontitis. After making an access to the pulp chamber, two orifices were easily detected while the third one was found by the aid of surgical microscope. The canals were cleaned and shaped using ProTaper Gold file and then obturated with BioCeram Sealer and Gutta-Percha points, using hydraulic bonded obturation technique. Tooth immediately received the final crown. Clinical and radiographical examination after a 3-month follow-up revealed successful peri-apical healing with no symptoms. A literature search was organized to review the past publications about management of mandibular second premolar with taurodontism or anomalies in the root canal system. The search was focused on cases reported in Medline, Scopus, and Google Scholar databases. The conclusion of the seven selected studies and reported cases revealed that proper visualization with advanced microscopes or computer imaging radiographs, negotiation of the root canals, and efficient instrumentation and obturation enhance endodontic success.

Tip and taper compatibility of accessory gutta-percha points with rotary and reciprocating instruments.

This study was conducted to evaluate and compare the tip and taper compatibility of accessory gutta-percha points (AGPs) with various rotary and reciprocating instruments. Using a profile analyzer, tip and taper measurements were taken of 10 AGPs of each of the 14 models available from Odous de Deus and the 4 models available from Dentsply-Maillefer. Diameter measurements were taken at 1-mm intervals, from 3 mm from the tip (D3) to 16 mm. Based on the mean values obtained, 3-dimensional (3D) models of the AGPs were drawn in Autodesk Fusion 360 and superimposed on 3D models of each instrument selected (Mtwo, Reciproc, RaCe, K3, and ProDesign Logic) to determine the compatibility between the instrument and the AGP. Data corresponding to the tips and tapers of the various AGPs, as well as the tip and taper differences between the AGPs and the instruments, were analyzed using descriptive statistics. The tapers of the AGPs were subject to the American National Standards Institute/American Dental Association No. 57 standard. The Odous de Deus extra-long medium and extra-long extra-medium AGPs were shown to be compatible with Mtwo, K3, and ProDesign Logic instruments with taper 0.06 and tip sizes 25 and 30, while the Dentsply fine and fine medium cones were compatible with Mtwo, RaCe, and K3 instruments with conicity of 0.04 and tip sizes 35 and 40. Both the Odous de Deus and Dentsply commercial brands included 2 AGP models with tip (D3) and taper compatibility with Mtwo, RaCe, K3, and/or Prodesign Logic instruments.

Investigation of the thermal and physicochemical behavior of two types of gutta-percha cones for back-filling the root canal.

Gutta-percha (Gp) is an inert thermoplastic polymer used as a filling to replace the dental pulp space, which has been reformulated to improve its three-dimensional sealing properties. Therefore, this study aimed to analyze the physical, chemical and thermal properties of two types of gutta-percha filling. As well as measuring the temperature distribution along the cone at the time of cutting through an in-situ test. Two commercially available brands of gutta-percha point were investigated: Conform Fit TM Gutta-Percha for ProTaper Gold® (PTG) (Dentsply Sirona), and Hygenic Gutta-Percha (Coltene whaledent). Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were selected for the thermal characterization of materials, and Fourier Transform Infrared Spectroscopy (FT-IR) for the chemical analysis of Gp cones. Regarding temperature distribution, it was evaluated using a thermographic camera (FLIR ONE® PRO by MicroUSB P/N 435-0011-01) at 0 to 20 s after the cutting process (n=11/group). Both materials have three fusion endotherms associated with the three crystalline phases of Gp, with similar temperatures but enthalpies that differ by 60%, the fusion enthalpy being higher for Conform Fit. In the chemical characterization, elements such as Zn, C, O, Ba, S and Si were found in both materials but in different proportions. Regarding the content of fillers, the Conform Fit presented around 30% of Gp polymer and 25% for the Hygenic. The morphological characterization shows a microtexturized coating in the form of bars on a micrometric scale for the Conform Fit, which could favor a better three-dimensional seal. In addition to that, in heat transfer studies they showed greater temperature control. The characterization of the materials allowed us to see the variation in terms of their composition and configuration to the Gp cones of two commercial brands. These variations directly modify the thermal behavior of the material. Key words:Gutta-percha, Conform Fit, Infrared thermography, Differential Scanning Calorimetry, Infrared Spectroscopy.

Evaluation of the efficacy of a novel disinfecting material on the surface topography of gutta-percha: An in vitro study.

The effect of chemical disinfection on gutta-percha (GP) has to be closely studied whether it affects surface topography and thereby causes leakage and reinfection of canals. The purpose of the study is to assess the surface topography of GP cones after disinfecting with a novel disinfecting material, graphene oxide (GO), and compare the same with other disinfecting materials, including sodium hypochlorite (NaOCl) and silver nanoparticles (AgNps). After determining the power (0.84) of the study, 48 GP cones were taken and categorized into four different groups based on disinfecting agents. Forty-eight GP cones (ISO size 30 6% taper, DIADENT) were taken and are randomly selected and grouped as follows according to the disinfecting agents: Group 1 - control (untreated GP points, n = 12), Group 2 - NaOCl (n = 12), Group 3 - AgNPs (n = 12), and Group 4 - GO (n = 12), respectively. After treating with the above disinfecting materials, the surface topography of samples was evaluated using atomic force microscopy. The data were analyzed statistically using one-way ANOVA and post hoc (Tukey's honestly significant difference) tests. IBM SPSS (version 21.0) software was used. The tests performed were one-way ANOVA and post hoc. Statistically, significance was set at a P ≤ 0.05. The root means square values and surface roughness values were lesser for the GO group and AgNPs when compared with the NaOCl group, which were statistically significant. Within the limitations of the study, this study had shown lesser surface topography deterioration of GP cones when treated with GO and AgNPs, whereas more deterioration was observed with NaOCl.

Evaluation of CPoint obturation system for voids &amp; gaps using digital microscope

ABSTRACT&#x0D; Aim: This study was aimed to evaluate the quality of CPoint obturation system by calculating the percentage of surface area of voids and gaps in different levels in comparison with Guttapercha point/GuttaFlow 2 and Guttacore/Endofill.&#x0D; Method: Sixty palatal roots of extracted upper first molars were prepared and divided into three groups of 20 samples each, the first group was obturated with CPoint/BC sealer, the second one was obturated with Guttapercha point/ GuttaFlow2 and the third was obturated with GuttaCore/Endofil. Each root sectioned into four sections at 8 mm, 6 mm, 4 mm, and 2 mm levels from the W.L and transferred to be photographed under digital microscope, the canal cross sectional area, and the area of voids and gaps were measured then surface area percentages of unfilled areas were calculated. Data then analyzed statistically using ANOVA and LSD tests.&#x0D; Results: Higher percentages of unfilled areas were observed in Group1 (p &lt; 0.01) in comparison to Group2 and Group3 except with S2 of Group3 (p &gt; 0.05). And there was no significant difference between Group2 and Group3 except at S2. The results of comparison among different&#x0D; &#x0D; sections within each group showed that there is a highly significant difference (p &lt; 0.01) between S2and (S8, S6, S4) within Group 1, in Group 2 the results showed that there is a highly significant difference between S8 and the other sections, and also showed a significant difference (p &lt; 0.05) between S2 and (S4, S6).&#x0D; Within Group 3 the results revealed significant difference between the (S4, S6) and the (S8, S2) sections.&#x0D; Conclusion: All systems showed voids and gaps and CPoint obturation system showed the highest percentage of unfilled areas and level of root section had an effect on voids and gaps distribution.

To Evaluate the Accuracy Between Two Different Electronic Apex Locators to Detect the Root Canal Perforation During Retreatment - An Ex-Vivo Study

Objectives: To evaluate the accuracy between two different electronic apex locators in detecting the root canal perforation in the middle and apical portion during retreatment. Methods: Sixty freshly extracted mandibular premolars were taken in to this study, which were divided into three groups of twenty each. Group I: Control Group, Group II: Positive control without perforation, Group III: Negative control with perforation. In all the groups, access cavity preparation was done followed by cleaning and shaping using X smart Endomotor and Protaper Gold file system (Dentsply Maillefer, Switzerland). The specimens were prepared such that perforation was made in group III on the mesial side of the root at middle portion approximately 5mm from the apex after determining working length by direct visualization and stored for the database. All the specimens were obturated by using AH plus sealer and F3 Protaper gold gutta percha points and later stored in incubator at temperature of 37°C for 7days. After 7 days, gutta percha was removed from group III samples using gutta percha solvent (Xylene), Neo-Endo retreatment files. These teeth were mounted on Protrain Endodontic training kit (Simit Dental, Italy) and perforation were detected using apex locators Dentaport Root ZX (J,Morita) and Propex Pixi (Dentsply Maillefer, Switzerland). The apical perforation were made at a distance 2mm from apex after the middle perforation were restored by using Type II GIC by keeping the 35 K file inside the canal and apical perforations were detected and the reading were recorded and stored for the database. Statistical Analysis: The data obtained were analyzed by using descriptive statistics, ANOVA (Analysis of Variance), Paired t test through SPSS for window (version 22.0). Findings: In case of middle third perforation of the root canal Dentaport Root ZX showed accuracy of 87.37% and Propexpixi 82.89%. In apical perforations the accuracies of Root ZX and Propex Pixi are 89.28% and 79.76% respectively. In the both the perforations, there was a statistically significant difference (P < 0.05). In both the perforations, Dentaport Root ZX showed more accuracy in detecting the perforation when compared with Propex Pixi apex locator. Novelty : This study provides a novel approach as it compares the accuracy between the Dentaport Root Zx and Propex Pixi in detection of middle and apical perforation during retreatment in Ex Vivo study. Keywords: Dentaport root ZX; Electronic apex locator (EAL); Propex pixi; Protrain endodontic training kit; Root canal perforation

Effects of chitosan-containing silver nanoparticles or chlorhexidine as the final irrigant on the bond strength of resin-based root canal sealers.

Background. This study evaluated the combined effects of silver nanoparticles (AgNPs) and chitosan on the dentin bond strength of resin-based root canal sealers using the push-out test and scanning electron microscopy (SEM). Methods. This in vitro study was conducted on 72 extracted mandibular premolar teeth. All the teeth were decoronated perpendicular to the long axis to leave a 13-mm root length. The root canals were prepared, and the samples were randomly divided into seven experimental groups and one control group based on final irrigation solutions. All the final irrigation procedures were performed for one minute. The root canals were dried using paper points and filled with a resin-based sealer and gutta-percha points using a lateral condensation technique. Sections measuring 2 mm in thickness were taken from the apical, middle, and coronal thirds of each root using a cutting machine. The push-out test was performed using a universal testing machine. Results. The solution of AgNPs combined with 0.4% chitosan showed higher bond strength in the coronal region than a combination with 0.2% chitosan. Samples treated with 0.4% chitosan solution exhibited a higher bond strength than the 0.2% chitosan group. There were no significant differences between chlorhexidine (CHX) solution alone and in combination with 0.2% or 0.4% chitosan solution. Conclusion. The combination of chitosan and AgNPs was as effective as CHX in improving the bond strength of resin-based sealers.

Biological Evaluation of the Effect of Root Canal Sealers Using a Rat Model.

Gutta-percha points and root canal sealers have been used for decades in endodontics for root canal obturation. With techniques such as single cone methods, the amount of sealer is larger, making their properties more critical. However, relatively few reports have comprehensively evaluated their biological effects. To this end, we evaluated three types of sealers, zinc oxide-fatty acid-, bio-glass- and methacrylate resin-containing sealers were considered. Their biological effects were evaluated using a rat subcutaneous implantation model. Each sealer was loaded inside a Teflon tube and implanted subcutaneously in the backs of rats. Inflammatory cells were observed around all samples 7 days after implantation and reduced after 28 days. Our results revealed that all samples were in contact with the subcutaneous tissue surrounding the sealer. Additionally, Ca and P accumulation was observed in only the bio-glass-containing sealer. Furthermore, each of the three sealers exhibited unique immune and inflammatory modulatory effects. In particular, bio-glass and methacrylate resin sealers were found to induce variable gene expression in adjacent subcutaneous tissues related to angiogenesis, wound healing, muscle tissue, and surrounding subcutaneous tissue. These results may help to understand the biological impacts of root canal sealers on surrounding biological tissues, guiding future research and comparisons with new generations of materials.

Healing Assessment of Osseous Defects after Surgical Removal of Periapical Lesions in the Presence of Hydroxyapatite, Nanohydroxyapatite, and a Combination of Nanohydroxyapatite and Platelet-rich Fibrin: A Clinical Study

Abstract: Aim: to evaluate the bone healing in failed endodontically treated teeth after surgical removal of periapical lesions and placement of hydroxyapatite (HA), nanohydroxyapatite (nHA) and a combination of nanohydroxyapatite with platelet rich fibrin (PRF) periapically. Subjects and methods: the study was conducted on twenty-four patients having periapical radiolucency in single rooted teeth. The selected teeth were divided into three groups: Group A, Group B, and Group C; of 8 teeth each. All the teeth were retreated in two visits. In the first visit the old filling was removed using Protaper retreatment files (Dentsply Sirona®) then irrigation with sodium hypochlorite 2.5% was done. All canals were dried and filled with Di-antibiotic paste (metronidazole and ciprofloxacin). In the second visit the canals were obturated with Pro Taper gutta-percha points and root canal sealer (Adseal resin sealer) followed by surgical intervention in the same day. A periapical curettage along with apicoectomy were established. In all the groups, root end cavity was prepared and filled with MTA (ProRoot MTA; DENTSPLY Tulsa Dental Specialties). In Group A, hydroxyapatite powder was packed in the curetted periapical defect. In Group B, nanohydroxyapatite powder was packed in the curetted periapical defect. In Group C, nanohydroxyapatite with PRF were mixed and packed in the curetted periapical defect. In all groups, patients recall visits were scheduled at 1, 3, and 6 months’ time intervals for clinical and radiological evaluation. Results: after one month; there was a statistically significant difference between the median percentage changes in lesions size in the three groups. Pair-wise comparisons between groups revealed that there was no statistically significant difference between group B (nHA) and group C (PRF and nHA) groups. Both showed statistically significantly higher median percentage reduction in lesions size than group A (HA group). After three as well as six months; there was no statistically significant difference between the median percentage decreases in lesions size in the three groups. Conclusion: It was concluded that nHA combination with PRF produced faster periapical healing (bone regeneration) in the first three months than nHA alone. However, HA produce periapical healing (bone regeneration) after six months.