Shaping ability of novel nickel-titanium systems in printed primary molars

Background Manual or mechanized instruments can be used for root canal preparation. Manual instrumentation using K-files is widely used in primary teeth, but there are many limitations. Mechanized root canal preparation can lead to easy access to all canals, decrease instrumentation time, and result in more funnel-shaped root canals, resulting in a more predictable uniform paste fill. Aim This study aimed to evaluate the shaping ability and instrumentation time of VDW.ROTATE (TM) and EdgeTaper Platinum (TM) during the preparation of resin-printed primary molars. Hand K-files were used as a reference for comparison. Design Sixty-six resin-based maxillary second primary molars, obtained from extracted tooth cone-beam computed tomography (CBCT) image and printed on a three-dimensional printer, were divided into three groups: VDW.ROTATE (TM), EdgeTaper Platinum (TM), and K-files. The specimens were scanned using CBCT imaging before and after root canal preparation. Images were registered using a dedicated software, and changes (Delta) in the canal area, volume, and untouched canal surface were calculated. Instrumentation time was evaluated. Data were statistically analyzed using the SPSS program. Results There was no significant difference among the tested file systems for Delta canal volume and area (p > .05). VDW.ROTATE (TM), however, showed significantly lower untouched canal surface area than other systems in all roots (p < .001). The VDW.ROTATE (TM) was found to be significantly faster (6.47 +/- 0.39 min) than EdgeTaper Platinum (TM) (7.71 +/- 0.73 min) and K-files (8.22 +/- 0.72 min), (p < .05). Conclusions The shaping ability and the instrumentation time were directly influenced by the root canal instrumentation system used during the preparation of resin-printed primary molars, with VDW.ROTATE (TM) being the faster system and associated with the lower amount of untouched canal surface area.Afyonkarahisar Health Sciences University Scientific Research Project Management Uni

Detection of Procedural Errors with Stainless Steel and NiTi Instruments by Undergraduate Students Using Conventional Radiograph and Cone Beam Computed Tomography

Introduction: This study investigated procedural errors made during root canal preparation using stainless steel and nickel-titanium (NiTi) instruments by undergraduate students, using two diagnostic imaging methods. Materials and Methods: Sixty human molars were divided into three groups (n=20; group 1: K-Flexofile, group 2: K3, and group 3: BioRace). The root canals were filled with gutta-percha and AH Plus. Periapical radiographs and cone beam computed tomography (CBCT) images were obtained to detect procedural errors made by undergraduate students during root canal preparation. Two examiners evaluated the presence or absence of fractured instruments, perforations and canal transportations. The agreement between observers was assessed using the kappa coefficient. The Kolmogorov-Smirnov, Fisher exact, ANOVA and Tukey tests were used for statistical analysis. The level of significance was set at 5%. Results: There were no significant differences in detecting procedural errors between two- and three-dimensional diagnostic imaging methods. There were no significant differences in procedural errors between stainless steel and NiTi instruments. Mean preparation time was recorded in minutes, and results were significantly different between the three groups. NiTi instruments had the lowest mean preparation time. Conclusion: Both periapical radiographs and CBCT identified procedural errors, however, three-dimensional images offered more diagnostic resources. The frequency of procedural errors was low for any of the endodontic instruments despite being used by inexperienced operators

Development of a model to assess cleaning and disinfection of complex root canal systems

The remaining debris and biofilm in the anatomical complexities of root canal systems can affect treatment outcomes. Files with asymmetric cross-section design may improve debris and biofilm removal from these difficult spaces during canal preparation. Tooth opacity and different densities of the remaining materials prevent the direct systematic assessment of the preparation process. The present study assessed remaining debris and biofilm using a novel transparent root canal model with novel approaches. Natural and simulated root canal samples with isthmus space were evaluated. Canal preparation by ProTaper Next and Revo-S asymmetric systems was evaluated in comparison to the standard ProTaper Universal symmetric system. The root canals were investigated by microcomputed tomography (micro-CTL confocal laser scanning microscopy (CLSML and optical coherence tomography (OCT) imaging tools. Data analysis was undertaken with SPSS (V. 24). Files with asymmetric cross-section and constant taper removed more debris and biofilm from the complex root canal system. The model allowed direct assessment of remaining materials and confirmed the novel imaging approach with the OCT. In conclusion, the asymmetric design improves debris and biofilm removal especially when used with a constant taper. The model was verified as an ideal system for assessing root canal treatment in vitro

Micro-computed tomographic evaluation of dentinal defects after root canal preparation with hyflex edm and vortex blue rotary systems

To evaluate the incidence of dentinal microcracks formation after root canal shaping procedures with HyFlex EDM and Vortex Blue rotary systems comparing with that of hand instrumentation using micro-computed tomography. Mandibular first molar teeth (n=60) having 50 to 200mesial root curvature were scanned using high resolution micro-CT imaging before root canal preparation to identify the presence of dentinal defects. Post-instrumentation cross-sectional images were taken and increased number and type of root defects were assessed and recorded. The data was statistically analysed by using chi-square test and McNemar?s test at a significance level of 5%. HyFlex EDM has shown greater increase in post instrumentation dentinal defects. Both rotary systems exhibited increased dentinal defects formation at coronal, middle regions which is statistically significant (P=0.042) when compared to apical region. HyFlex EDM has shown greater increase in post instrumentation dentinal defects followed by Vortex Blue rotary system and hand instrumentation resulted minimal defects

A comparison of root canal transportation and centering ability between WaveOne® Gold and Protaper Next® files, using microcomputed tomography

This study compared the transportation and centering ability of ProTaper Next (PTN) and WaveOne Gold (WOG) files in curved permanent teeth using micro-computed tomography (μCT). Twenty-four molar teeth with curved roots were divided randomly into two equal groups. The root canals of one group was prepared using PTN files, and the other using WOG files. Pre-instrumentation and post-instrumentation μCT imaging were taken for all the teeth. The dentine thickness of the pre-and the post-instrumentation cross sections was measured at eight different points at three levels: 3, 5 and 7mm from the apex, by two dentists using image analysis software. The data were analysed using one-way ANOVA, at a 5% significance level. The transportation in both groups was within the range accepted in the literature. The WOG file exhibited significantly less root canal transportation compared with the PTN file (p=0.001). The WOG file showed a significantly (p&lt;0.001) higher mean centering ratio of 0.4286 when compared to that of PTN at 0.2448. Using a novel technique to measure canal transportation, this study found that the WOG and PTN systems were both suitable for preparation of curved molar root canals, but the WOG showed significantly less canal transportation and better centering ability than the PTN system

Dentistry

The specialty of Dental Surgery has progressed from the "blood and acrylic" of the early seventies. Dentistry has undergone a quantum leap over the past twenty-five years, with improvements in both technique and technology, bringing us the sophisticated procedures used in today's practice.peer-reviewe

Nanodiamond-Gutta Percha Composite Biomaterials for Root Canal Therapy.

Root canal therapy (RCT) represents a standard of treatment that addresses infected pulp tissue in teeth and protects against future infection. RCT involves removing dental pulp comprising blood vessels and nerve tissue, decontaminating residually infected tissue through biomechanical instrumentation, and root canal obturation using a filler material to replace the space that was previously composed of dental pulp. Gutta percha (GP) is typically used as the filler material, as it is malleable, inert, and biocompatible. While filling the root canal space with GP is the standard of care for endodontic therapies, it has exhibited limitations including leakage, root canal reinfection, and poor mechanical properties. To address these challenges, clinicians have explored the use of alternative root filling materials other than GP. Among the classes of materials that are being explored as novel endodontic therapy platforms, nanodiamonds (NDs) may offer unique advantages due to their favorable properties, particularly for dental applications. These include versatile faceted surface chemistry, biocompatibility, and their role in improving mechanical properties, among others. This study developed a ND-embedded GP (NDGP) that was functionalized with amoxicillin, a broad-spectrum antibiotic commonly used for endodontic infection. Comprehensive materials characterization confirmed improved mechanical properties of NDGP over unmodified GP. In addition, digital radiography and microcomputed tomography imaging demonstrated that obturation of root canals with NDGP could be achieved using clinically relevant techniques. Furthermore, bacterial growth inhibition assays confirmed drug functionality of NDGP functionalized with amoxicillin. This study demonstrates a promising path toward NDGP implementation in future endodontic therapy for improved treatment outcomes

Effect of time lapse on the diagnostic accuracy of cone beam computed tomography for detection of vertical root fractures

Accurate and early diagnosis of vertical root fractures (VRFs) is imperative to prevent extensive bone loss and unnecessary endodontic and prosthodontic treatments. The aim of this study was to assess the effect of time lapse on the diagnostic accuracy of cone beam computed tomography (CBCT) for VRFs in endodontically treated dog’s teeth. Forty-eight incisors and premolars of three adult male dogs underwent root canal therapy. The teeth were assigned to two groups: VRFs were artificially induced in the first group (n=24) while the teeth in the second group remained intact (n=24). The CBCT scans were obtained by NewTom 3G unit immediately after inducing VRFs and after one, two, three, four, eight, 12 and 16 weeks. Three oral and maxillofacial radiologists blinded to the date of radiographs assessed the presence/absence of VRFs on CBCT scans. The sensitivity, specificity and accuracy values were calculated and data were analyzed using SPSS v.16 software and ANOVA. The total accuracy of detection of VRFs immediately after surgery, one, two, three, four, eight, 12 and 16 weeks was 67.3%, 68.7%, 66.6%, 64.6%, 64.5%, 69.4%, 68.7%, 68% respectively. The effect of time lapse on detection of VRFs was not significant (p>0.05). Overall sensitivity, specificity and accuracy of CBCT for detection of VRFs were 74.3%, 62.2%, 67.2% respectively. Cone beam computed tomography is a valuable tool for detection of VRFs. Time lapse (four months) had no effect on detection of VRFs on CBCT scans. © 2016, Associacao Brasileira de Divulgacao Cientifica. All rights reserved

The Effect of Intra-Canal Posts on Diagnostic Accuracy of Cone Beam Computed Tomography and Digital Radiography in Detection of Vertical Root Fractures

Objective: Diagnosis of vertical root fractures (VRFs) is critical in endodontics. Cone Beam Computed Tomography (CBCT) has significantly enhanced image quality compared to digital radiography (DR) and greatly aids the diagnosis of VRFs but, metal artifacts has remained as a problem in VRF detection. This study evaluated the effect of intra canal posts on the diagnostic accuracy of CBCT and DR for detection of VRFs.Methods: In this experimental in vitro study eighty extracted human premolar teeth were cut at the cement-enamel junction .After root canal preparation, the casting posts were made. Samples were randomly divided into 2 groups of 40; group one with induced fracture and group 2 as the control group. Radiographs were taken for all specimens with and without posts with both imaging systems. Three observers assessed the presence or absence of VRF. Accuracy of the two imaging systems and the effect of post on VRF detection were assessed, using two-way ANOVA test and inter observer coefficient agreement was calculated.Results: Absolute diagnostic sensitivity and specificity of CBCT and absolute sensitivity of DR in the group with intracanal posts were significantly lower than those in the group without posts (p=0.023, p=0.034 and p=0.034 respectively). Absolute specificity of DR in the group with posts was significantly higher than that of the CBCT (p=0.014). The absolute and complete specificity of CBCT in the group without posts was significantly higher than those of DR (p=0.024, p=0.04). No statistically significant difference was found in inter observer agreement coefficient in presence or absence of posts or between the two imaging systems (p=0.119).Conclusion: Intra canal posts decreased the diagnostic accuracy of CBCT and DR for detection of VRFs and this reduction was greater in CBCT. However, absolute specificity of DR in the group with posts was significantly higher than that of the CBCT, where as CBCT images of teeth without posts still had higher diagnostic accuracy than DR

Effect of Metal Artifacts on Detection of Vertical Root Fractures Using Two Cone Beam Computed Tomography Systems

Introduction: Vertical root fracture (VRF) is common in endodontically treated teeth. Conventional and digital radiographies have limitations for detection of VRFs. Cone-beam computed tomography (CBCT) offers greater detection accuracy of VRFs in comparison with conventional radiography. This study compared the effects of metal artifacts on detection of VRFs by using two CBCT systems. Methods and Materials: Eighty extracted premolars were selected and sectioned at the level of the cemento-enamel junction (CEJ). After preparation, root canals were filled with gutta-percha. Subsequently, two thirds of the root fillings were removed for post space preparation and a custom-made post was cemented into each canal. The teeth were randomly divided into two groups (n=40). In the test group, root fracture was created with Instron universal testing machine. The control teeth remained intact. CBCT scans of all teeth were obtained with either New Tom VGI or Soredex Scanora 3D. Three observers analyzed the images for detection of VRF. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for VRF detection and percentage of probable cases were calculated for each imaging system and compared using non-parametric tests considering the non-normal distribution of data. The inter-observer reproducibility was calculated using the weighted kappa coefficient. Results: There were no statistically significant differences in sensitivity, specificity, PPV and NPV between the two CBCT systems. Conclusion: The effect of metal artifacts on VRF detection was not significantly different between the two CBCT systems.Keywords: Cast Post; CBCT; Cone-Beam Computed Tomography; Vertical Root Fractur