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George T J Huang - One of the best experts on this subject based on the ideXlab platform.
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nanobubble enhanced antimicrobial agents a promising approach for regenerative endodontics
Journal of Endodontics, 2020Co-Authors: George T J Huang, Misako Nakashima, Hassan Shawli, Koichiro Iohara, Mohamed Tarrosh, Adham A AzimAbstract:Abstract Introduction In this study, we investigated the properties of nanobubble (NB) water and its effect on smear layer removal and strengthening the efficiency of disinfecting agents used in regenerative endodontic treatment. Methods NB water was generated in a NB Generator. The NB size, concentration, and pH were measured. Porcine teeth were enlarged to size 60 by using hand-files and irrigated with either NB water or 17% EDTA or received no further irrigation. The ability of irrigants to remove the smear layer was evaluated by using a scanning electron microscope (9 Roots/group). Other samples (6 Roots/group) were subjected to Vickers hardness test to determine the dentin microhardness. Autofluorescent tetracycline mixed with distilled water or NB water was placed inside the Root Canal Space of porcine teeth, and the depth of medicament penetration into the dentinal tubules was visualized by using fluorescent stereomicroscope (5 Roots/group). For the disinfection experiment, human Roots were prepared, autoclaved, and inoculated with Enterococcus faecalis for 3 weeks. Canals were then disinfected by (1) standard needle irrigation (SNI) with 5.25% NaOCl, (2) 5.25% NaOCl with ultrasonication (US), (3) 5.25% NaOCl + XP finisher (XP), (4) SNI with 1.5% NaOCl, or (5) SNI with 1.5% NaOCl in NB water (5 Roots/group). Teeth were split open and stained with LIVE/DEAD BackLight and visualized by using confocal laser scanning microscope (CLSM) at the coronal, middle, and apical thirds of the Canal. The ratio of dead/total bacteria in the dentinal tubules at various depth levels (50, 100, and 150 μm) was calculated. Results NB water was more effective in removing smear layer than 17% EDTA and could allow infiltration of tetracycline into the dentinal tubule more than 1 mm. NB water did not alter the dentin microhardness compared with 17% EDTA (P .05), ie, these groups had stronger bacterial killing than 1.5% NaOCl (P .05). Conclusions NB water can allow smear layer removal and enhance tubular penetration of medicaments without changing dentin microhardness. In large Canal models, NB water appears to improve the tubular disinfection capacity of lower concentration of NaOCl up to 50 μm. On the other hand, the use of irrigation activation (US or XP) did not provide any added disinfection into the dentinal tubules compared with SNI. These results suggest that NB water may be a promising adjunct to endodontic irrigants and medicaments.
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the coming era of regenerative endodontics what an endodontist needs to know
Alpha Omegan, 2011Co-Authors: George T J HuangAbstract:Recently, two new clinical concepts have emerged for the management of endodontically compromised immature permanent teeth. One involves a revitalization approach to achieve tissue generation and regeneration in the Root Canal system. In this method, new living tissue is expected to form in the cleaned Canal Space allowing continued Root development in terms of both length and thickness. The other is the active pursuit of pulp/dentine regeneration via tissue engineering technology to implant or re-grow pulps. Although the technology is still at its infancy, it has potential to benefit immature pulpless teeth by allowing continued growth and maturation. Evidence has shown that using dental stem cells, pulp and dentin can be regenerated in the Root Canal Space. It is foreseeable that a decade or two from now, regenerative endodontics is likely to be an alternative treatment modality for clinical endodontics. It is therefore important for us to understand stem cells and tissue regeneration and be prepared for this clinical practice.
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stem progenitor cell mediated de novo regeneration of dental pulp with newly deposited continuous layer of dentin in an in vivo model
Tissue Engineering Part A, 2010Co-Authors: George T J Huang, Takayoshi Yamaza, Lonnie D Shea, Farida Djouad, Nastaran Z Kuhn, Rocky S Tuan, Songtao ShiAbstract:The ultimate goal of this study is to regenerate lost dental pulp and dentin via stem/progenitor cell–based approaches and tissue engineering technologies. In this study, we tested the possibility of regenerating vascularized human dental pulp in emptied Root Canal Space and producing new dentin on existing dentinal walls using a stem/progenitor cell–mediated approach with a human Root fragment and an immunocompromised mouse model. Stem/progenitor cells from apical papilla and dental pulp stem cells were isolated, characterized, seeded onto synthetic scaffolds consisting of poly-D,L-lactide/glycolide, inserted into the tooth fragments, and transplanted into mice. Our results showed that the Root Canal Space was filled entirely by a pulp-like tissue with well-established vascularity. In addition, a continuous layer of dentin-like tissue was deposited onto the Canal dentinal wall. This dentin-like structure appeared to be produced by a layer of newly formed odontoblast-like cells expressing dentin sialophosphoprotein, bone sialoprotein, alkaline phosphatase, and CD105. The cells in regenerated pulp-like tissue reacted positively to anti-human mitochondria antibodies, indicating their human origin. This study provides the first evidence showing that pulp-like tissue can be regenerated de novo in emptied Root Canal Space by stem cells from apical papilla and dental pulp stem cells that give rise to odontoblast-like cells producing dentin-like tissue on existing dentinal walls.
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stem progenitor cell mediated de novo regeneration of dental pulp with newly deposited continuous layer of dentin in an in vivo model
Tissue Engineering Part A, 2010Co-Authors: George T J Huang, Takayoshi Yamaza, Lonnie D Shea, Farida Djouad, Nastaran Z Kuhn, Rocky S TuanAbstract:The ultimate goal of this study is to regenerate lost dental pulp and dentin via stem/progenitor cell–based approaches and tissue engineering technologies. In this study, we tested the possibility of regenerating vascularized human dental pulp in emptied Root Canal Space and producing new dentin on existing dentinal walls using a stem/progenitor cell–mediated approach with a human Root fragment and an immunocompromised mouse model. Stem/progenitor cells from apical papilla and dental pulp stem cells were isolated, characterized, seeded onto synthetic scaffolds consisting of poly-D,L-lactide/glycolide, inserted into the tooth fragments, and transplanted into mice. Our results showed that the Root Canal Space was filled entirely by a pulp-like tissue with well-established vascularity. In addition, a continuous layer of dentin-like tissue was deposited onto the Canal dentinal wall. This dentin-like structure appeared to be produced by a layer of newly formed odontoblast-like cells expressing dentin sialophos...
Ali Nosrat - One of the best experts on this subject based on the ideXlab platform.
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regenerative endodontic treatment as a biologically based approach for non surgical retreatment of immature teeth
Journal of Endodontics, 2019Co-Authors: Jerome J Cymerman, Ali NosratAbstract:Abstract Introduction The goal of regenerative endodontic treatment (RET) is to regenerate the pulp-dentin complex in immature teeth with pulp necrosis. There is no consensus in using RET in previously treated teeth. This article reports on long-term outcomes of RET in previously treated immature teeth. Methods Previously treated immature teeth with signs/symptoms of failure were included. After local anesthesia and rubber dam isolation, the Root Canal filling material was removed without the use of chemical solvents. The Root Canals were irrigated with 6% sodium hypochlorite using an EndoVac (Kerr Endodontics, Culver City, CA), and a creamy mix of metronidazole and ciprofloxacin was placed in the Canals for 4 weeks. At the second visit, the antibiotic dressing was removed using 17% EDTA. Bleeding was induced into the Root Canal Space, and SynOss Putty (Collagen Matrix Inc, Oakland, NJ) was placed. Bioceramic putty was placed over the SynOss Putty, and the teeth were restored at a subsequent visit. Results Five teeth in 4 patients were included. The patients’ ages ranged from 14–46 years. Recall examinations were performed from 20 to 72 months with an average of 54.4 months. The apical openings of the teeth ranged from 1–3.7 mm. All teeth were functional and asymptomatic at the recall visits. All periapical lesions resolved with partial or complete mineralization of the Root Canals, and all teeth showed partial to complete apical closure at the follow-up visits. Conclusions RET can be a viable option for nonsurgical retreatment of immature teeth. This article adds a new perspective to the field of regenerative endodontics.
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conservative management of class 4 invasive cervical Root resorption using calcium enriched mixture cement
Journal of Endodontics, 2016Co-Authors: Saeed Asgary, Ali NosratAbstract:Class 4 invasive cervical Root resorption (ICRR) presents a treatment dilemma in endodontics. The widely accepted treatment options for a class 4 ICRR are to leave these teeth untreated for as long as they are asymptomatic or extraction. This report presents a conservative approach for the management of class 4 ICRR. A 28-year-old woman was referred for Root Canal treatment of tooth #26. The patient had a history of orthodontic treatment. Radiographic evaluation showed class 4 ICRR that had perforated the Root Canal Space, a radiolucent crestal bony defect, and a periapical lesion. Clinically, a deep (6-mm) probing area was found on the mesial side of the tooth that bled on probing. The tooth was sensitive to percussion. After the treatment options were discussed with the patient, she chose to save the tooth. After complete chemomechanical preparation of the Root Canal, the entire Canal Space and perforation area were filled with calcium-enriched mixture cement. No attempt was made to mechanically remove the resorptive lacuna. Twenty four months after treatment, the tooth was functional and asymptomatic, and probing was within normal limits (<3 mm) with no bleeding during probing. Radiographic examination revealed no progression of resorption, osseous healing of the crestal bony defect, and healing of the periapical lesion. Obturation of the Root Canal Space with calcium-enriched mixture cement may be a viable treatment option for an otherwise non-treatable tooth with class 4 invasive cervical Root resorption.
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is pulp regeneration necessary for Root maturation
Journal of Endodontics, 2013Co-Authors: Ali Nosrat, Kunwar Vir, Lamar M Hicks, Ashraf F FouadAbstract:Abstract Introduction True regeneration of the dental pulp-dentin complex in immature teeth with necrotic pulps has not been shown histologically. It is not known to what extent this true tissue regeneration is necessary to achieve clinically acceptable outcomes. Methods This case report describes the treatment of a patient with an immature maxillary right central incisor with a history of impact trauma and enamel-dentin crown fracture. A diagnosis of pulp necrosis with acute apical abscess was established. A regenerative endodontic protocol that used a paste containing Augmentin for 5 weeks as an intraCanal medicament was used. Results Follow-ups at 9, 12, 17, and 31 months revealed complete osseous healing of the periapical lesion and formation of the Root apex, but without increase in Root length. Clinically, the tooth was functional, asymptomatic, and nonresponsive to pulp vitality tests. The crown discolored over time. On reentering the Root Canal, no tissues were observed under magnification inside the Root Canal Space. The Root Canal treatment was completed with mineral trioxide aggregate obturation. Conclusions Augmentin might be an acceptable choice for Root Canal disinfection in regenerative endodontic procedures. The protocol for regenerative endodontic treatment is not predictable for pulp-dentin regeneration. Formation of the Root apex is possible without pulp regeneration.
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pulp regeneration in previously infected Root Canal Space
Endodontic Topics, 2013Co-Authors: Ashraf F Fouad, Ali NosratAbstract:Contemporary pulp revascularization procedures have been successful in achieving endodontic infection control and promoting the Root mineralization process. However, there is still no agreement on the methods to produce predictable clinical outcomes or optimal disinfection protocols. Furthermore, there is no evidence for actual pulp regeneration in humans or in in situ animal models. This review will outline the various factors involved in undertaking this procedure, with a special emphasis on the antimicrobial strategies employed and the available information on their efficacy. Areas in which information is lacking and research is needed will also be presented.
Adham A Azim - One of the best experts on this subject based on the ideXlab platform.
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nanobubble enhanced antimicrobial agents a promising approach for regenerative endodontics
Journal of Endodontics, 2020Co-Authors: George T J Huang, Misako Nakashima, Hassan Shawli, Koichiro Iohara, Mohamed Tarrosh, Adham A AzimAbstract:Abstract Introduction In this study, we investigated the properties of nanobubble (NB) water and its effect on smear layer removal and strengthening the efficiency of disinfecting agents used in regenerative endodontic treatment. Methods NB water was generated in a NB Generator. The NB size, concentration, and pH were measured. Porcine teeth were enlarged to size 60 by using hand-files and irrigated with either NB water or 17% EDTA or received no further irrigation. The ability of irrigants to remove the smear layer was evaluated by using a scanning electron microscope (9 Roots/group). Other samples (6 Roots/group) were subjected to Vickers hardness test to determine the dentin microhardness. Autofluorescent tetracycline mixed with distilled water or NB water was placed inside the Root Canal Space of porcine teeth, and the depth of medicament penetration into the dentinal tubules was visualized by using fluorescent stereomicroscope (5 Roots/group). For the disinfection experiment, human Roots were prepared, autoclaved, and inoculated with Enterococcus faecalis for 3 weeks. Canals were then disinfected by (1) standard needle irrigation (SNI) with 5.25% NaOCl, (2) 5.25% NaOCl with ultrasonication (US), (3) 5.25% NaOCl + XP finisher (XP), (4) SNI with 1.5% NaOCl, or (5) SNI with 1.5% NaOCl in NB water (5 Roots/group). Teeth were split open and stained with LIVE/DEAD BackLight and visualized by using confocal laser scanning microscope (CLSM) at the coronal, middle, and apical thirds of the Canal. The ratio of dead/total bacteria in the dentinal tubules at various depth levels (50, 100, and 150 μm) was calculated. Results NB water was more effective in removing smear layer than 17% EDTA and could allow infiltration of tetracycline into the dentinal tubule more than 1 mm. NB water did not alter the dentin microhardness compared with 17% EDTA (P .05), ie, these groups had stronger bacterial killing than 1.5% NaOCl (P .05). Conclusions NB water can allow smear layer removal and enhance tubular penetration of medicaments without changing dentin microhardness. In large Canal models, NB water appears to improve the tubular disinfection capacity of lower concentration of NaOCl up to 50 μm. On the other hand, the use of irrigation activation (US or XP) did not provide any added disinfection into the dentinal tubules compared with SNI. These results suggest that NB water may be a promising adjunct to endodontic irrigants and medicaments.
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comparison between single file rotary systems part 1 efficiency effectiveness and adverse effects in endodontic retreatment
Journal of Endodontics, 2018Co-Authors: Adham A Azim, Mohamed Tarrosh, Katharina A Azim, Howard H Wang, Lucila PiaseckiAbstract:Abstract Introduction The aim of this study was to evaluate in vitro the performance of 3 single-file systems: WaveOne Gold Primary (WOG; Dentsply Sirona, Ballaigues, Switzerland), Hyflex EDM “one file” (EDM; Coltene/Whaledent, Alstatten, Switzerland), and XP Shaper (XP; FKG, La Chaux de Fonds, Switzerland), for nonsurgical endodontic retreatment on mandibular anterior teeth in regard to the amount of remaining filling material inside the Canal, debris extrusion, and operation time. Methods Sixty extracted standardized mandibular incisors presenting with a single oval Canal were prepared to size 30.04 and obturated using warm vertical condensation. After 30 days (37°C, 100% humidity), teeth were randomly divided into 3 groups (n = 20) according to the file used for retreatment (WOG, EDM, or XP operated at 3000 rpm). During the retreatment procedures, preweighed vials were used to collect apically extruded debris, and the time required to remove the filling material was recorded in seconds. Cone-beam computed tomographic scans were taken before and after the retreatment to determine the amount of remaining filling material inside the Root Canal Space. Statistical analysis was performed using the Kruskal-Wallis test, 1-way analysis of variance, and the Pearson test at a 5% significance level. Results There was a statistically significant difference among the groups regarding the instrumentation time (P .05). Conclusions XP was the most efficient in gutta-percha removal from the Canals when operated at a higher speed (3000 rpm) followed by EDM and WOG.
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a miniature swine model for stem cell based de novo regeneration of dental pulp and dentin like tissue
Tissue Engineering Part C-methods, 2018Co-Authors: Jie Liu, Xiaofei Zhu, Chaoan Chen, Hacer Aksel, Adham A AzimAbstract:The goal of this study was to establish mini-swine as a large animal model for stem cell-based pulp regeneration studies. Swine dental pulp stem cells (sDPSCs) were isolated from mini-swine and characterized in vitro. For in vivo studies, we first employed both ectopic and semi-orthotopic study models using severe combined immunodeficiency mice. One is hydroxyapatite-tricalcium phosphate (HA/TCP) model for pulp-dentin complex formation, and the other is tooth fragment model for complete pulp regeneration with new dentin depositing along the Canal walls. We found that sDPSCs are similar to their human counterparts exhibiting mesenchymal stem cell characteristics with ability to form colony forming unit-fibroblastic and odontogenic differentiation potential. sDPSCs formed pulp-dentin complex in the HA/TCP model and showed pulp regeneration capacity in the tooth fragment model. We then tested orthotopic pulp regeneration on mini-swine including the use of multi-Rooted teeth. Using autologous sDPSCs carried by hydrogel and transplanted into the mini-swine Root Canal Space, we observed regeneration of vascularized pulp-like tissue with a layer of newly deposited dentin-like (rD) tissue or osteodentin along the Canal walls. In some cases, dentin bridge-like structure was observed. Immunohistochemical analysis detected the expression of nestin, dentin sialophosphoprotein, dentin matrix protein 1, and bone sialoprotein in odontoblast-like cells lining against the produced rD. We also tested the use of allogeneic sDPSCs for the same procedures. Similar findings were observed in allogeneic transplantation. This study is the first to show an establishment of mini-swine as a suitable large animal model utilizing multi-Rooted teeth for further cell-based pulp regeneration studies.
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xp shaper a novel adaptive core rotary instrument micro computed tomographic analysis of its shaping abilities
Journal of Endodontics, 2017Co-Authors: Adham A Azim, Lucila Piasecki, Ulisses Xavier Da Silva Neto, Alessandra Timponi Goes Cruz, Katharina A AzimAbstract:Abstract Introduction The aim of this study was to investigate the shaping abilities of the XP Shaper (FKG, La Chaux-de-Fonds, Switzerland) and compare the findings with Vortex Blue (Dentsply Tulsa Dental Specialties, Tulsa, OK) using micro–computed tomographic imaging. Methods Twenty matched, extracted, mandibular, central incisors with a single, oval Canal were scanned preoperatively at 25-μm resolution and postoperatively after instrumentation with either Vortex Blue in a crown-down manner up to size 30.04 or XP Shaper. The percent of untouched walls, changes in Canal volume and surface area, the amount of dentin removed, debris remaining in the Canal, and the preparation taper were determined. The total time required for instrumentation using each technique was calculated in seconds. Statistical analysis was used to compare between both groups using repeated measures multivariate analysis of variance with Bonferroni correction for post hoc comparison and independent sample t tests. Results The XP Shaper significantly increased the Canal volume ( F = 77.948, P F = 5.543, P = .030), and amount of dentin removed ( F = 10.044, P = .001) and had significantly less untouched walls (38.6% ± 8.1%) compared with VB (58.8% ± 8.5%). There was less debris at all levels of the Canal in the XP Shaper group. Results were almost significant ( P = .059). The XP Shaper was also significantly faster in completing the mechanical preparation of the Root Canal Space by almost 1 minute ( t = 6.216, P Conclusions The XP Shaper can expand beyond its core size to adapt to the anatomy of the Root Canal Space. The XP Shaper can prepare and touch more Canal walls in oval-shaped Canals compared with Vortex Blue. However, the final preparation taper will vary according to the anatomy of the treated tooth.
Rocky S Tuan - One of the best experts on this subject based on the ideXlab platform.
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stem progenitor cell mediated de novo regeneration of dental pulp with newly deposited continuous layer of dentin in an in vivo model
Tissue Engineering Part A, 2010Co-Authors: George T J Huang, Takayoshi Yamaza, Lonnie D Shea, Farida Djouad, Nastaran Z Kuhn, Rocky S Tuan, Songtao ShiAbstract:The ultimate goal of this study is to regenerate lost dental pulp and dentin via stem/progenitor cell–based approaches and tissue engineering technologies. In this study, we tested the possibility of regenerating vascularized human dental pulp in emptied Root Canal Space and producing new dentin on existing dentinal walls using a stem/progenitor cell–mediated approach with a human Root fragment and an immunocompromised mouse model. Stem/progenitor cells from apical papilla and dental pulp stem cells were isolated, characterized, seeded onto synthetic scaffolds consisting of poly-D,L-lactide/glycolide, inserted into the tooth fragments, and transplanted into mice. Our results showed that the Root Canal Space was filled entirely by a pulp-like tissue with well-established vascularity. In addition, a continuous layer of dentin-like tissue was deposited onto the Canal dentinal wall. This dentin-like structure appeared to be produced by a layer of newly formed odontoblast-like cells expressing dentin sialophosphoprotein, bone sialoprotein, alkaline phosphatase, and CD105. The cells in regenerated pulp-like tissue reacted positively to anti-human mitochondria antibodies, indicating their human origin. This study provides the first evidence showing that pulp-like tissue can be regenerated de novo in emptied Root Canal Space by stem cells from apical papilla and dental pulp stem cells that give rise to odontoblast-like cells producing dentin-like tissue on existing dentinal walls.
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stem progenitor cell mediated de novo regeneration of dental pulp with newly deposited continuous layer of dentin in an in vivo model
Tissue Engineering Part A, 2010Co-Authors: George T J Huang, Takayoshi Yamaza, Lonnie D Shea, Farida Djouad, Nastaran Z Kuhn, Rocky S TuanAbstract:The ultimate goal of this study is to regenerate lost dental pulp and dentin via stem/progenitor cell–based approaches and tissue engineering technologies. In this study, we tested the possibility of regenerating vascularized human dental pulp in emptied Root Canal Space and producing new dentin on existing dentinal walls using a stem/progenitor cell–mediated approach with a human Root fragment and an immunocompromised mouse model. Stem/progenitor cells from apical papilla and dental pulp stem cells were isolated, characterized, seeded onto synthetic scaffolds consisting of poly-D,L-lactide/glycolide, inserted into the tooth fragments, and transplanted into mice. Our results showed that the Root Canal Space was filled entirely by a pulp-like tissue with well-established vascularity. In addition, a continuous layer of dentin-like tissue was deposited onto the Canal dentinal wall. This dentin-like structure appeared to be produced by a layer of newly formed odontoblast-like cells expressing dentin sialophos...
Gustavo Dedeus - One of the best experts on this subject based on the ideXlab platform.
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safe mechanical preparation with reciprocation movement without glide path creation result from a pool of 673 Root Canals
Brazilian Dental Journal, 2016Co-Authors: Evaldo Rodrigues, Gustavo Dedeus, Erick Miranda Souza, Emmanuel Joao Nogueira Leal SilvaAbstract:The aim of the present study was to prospectively assess the frequency of teeth in which the Reciproc instruments were able to reach the full working length (WL). This case series study enrolled 277 consecutive teeth requiring primary endodontic treatment performed with the Reciproc system (VDW) without a previous glide path by 3 experienced endodontists. Instruments R25, R40 or R50 were selected, respectively, for narrow, medium and large Canals, according to the preoperative radiographs, as per manufacturer recommendation. Canals were instrumented and classified as reaching the full WL (RFWL) and not reaching the full WL (NRFWL), according to the ability of the Reciproc instrument to reach without a glide path the full electronically determined WL. Finally, Canals were filled using a single matched cone technique. Pearson's squared-chi test compared the frequency distributions of Canals classified as RFWL and NRFWL. From a total pool of 673 Root Canals, Reciproc instruments reached the FWL in 96.28% of cases and 3 fractures occurred. For narrow Canals the percentage of RFWL was 95.37% with 3 fractures. For medium and large Canals, the R40 or R50 instruments reached the FWL in 98.51% and 97.62% of the cases respectively, with no fracture. Enlarging of Root Canals using the Reciproc instruments up to the FWL without a glide path is successful in a great percentage of cases. This case series suggests the possibility of using a single instrument to enlarge the Root Canal Space of teeth by a simpler approach without an a prioriglide path procedure.
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exploiting the potential of free software to evaluate Root Canal biomechanical preparation outcomes through micro ct images
International Endodontic Journal, 2015Co-Authors: Aline De Almeida Neves, Haimon Diniz Lopes Alves, R T Lopes, Sidnei Paciornik, Emmanuel Joao Nogueira Leal Silva, J M Roter, F G Belladona, Gustavo DedeusAbstract:Aim To propose an automated image processing routine based on free software to quantify Root Canal preparation outcomes in pairs of sound and instrumented Roots after micro-CT scanning procedures. Methodology Seven mesial Roots of human mandibular molars with different Canal configuration systems were studied: (i) Vertucci's type 1, (ii) Vertucci′s type 2, (iii) two individual Canals, (iv) Vertucci′s type 6, Canals (v) with and (vi) without debris, and (vii) Canal with visible pulp calcification. All teeth were instrumented with the BioRaCe system and scanned in a Skyscan 1173 micro-CT before and after Canal preparation. After reconstruction, the instrumented stack of images (IS) was registered against the preoperative sound stack of images (SS). Image processing included contrast equalization and noise filtering. Sound Canal volumes were obtained by a minimum threshold. For the IS, a fixed conservative threshold was chosen as the best compromise between instrumented Canal and dentine whilst avoiding debris, resulting in instrumented Canal plus empty Spaces. Arithmetic and logical operations between sound and instrumented stacks were used to identify debris. Noninstrumented dentine was calculated using a minimum threshold in the IS and subtracting from the SS and total debris. Removed dentine volume was obtained by subtracting SS from IS. Results Quantitative data on total debris present in the Root Canal Space after instrumentation, noninstrumented areas and removed dentine volume were obtained for each test case, as well as three-dimensional volume renderings. Conclusion After standardization of acquisition, reconstruction and image processing micro-CT images, a quantitative approach for calculation of Root Canal biomechanical outcomes was achieved using free software.
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assessing accumulated hard tissue debris using micro computed tomography and free software for image processing and analysis
Journal of Endodontics, 2014Co-Authors: Gustavo Dedeus, Marco Aurelio Versiani, Juliana Marins, Aline De Almeida Neves, Claudia Reis, Sandra Rivera Fidel, Haimon Diniz Lopes Alves, R T Lopes, Sidnei PaciornikAbstract:Abstract Introduction The accumulation of debris occurs after Root Canal preparation procedures specifically in fins, isthmus, irregularities, and ramifications. The aim of this study was to present a step-by-step description of a new method used to longitudinally identify, measure, and 3-dimensionally map the accumulation of hard-tissue debris inside the Root Canal after biomechanical preparation using free software for image processing and analysis. Methods Three mandibular molars presenting the mesial Root with a large isthmus width and a type II Vertucci's Canal configuration were selected and scanned. The specimens were assigned to 1 of 3 experimental approaches: (1) 5.25% sodium hypochlorite + 17% EDTA, (2) bidistilled water, and (3) no irrigation. After Root Canal preparation, high-resolution scans of the teeth were accomplished, and free software packages were used to register and quantify the amount of accumulated hard-tissue debris in either Canal Space or isthmus areas. Results Canal preparation without irrigation resulted in 34.6% of its volume filled with hard-tissue debris, whereas the use of bidistilled water or NaOCl followed by EDTA showed a reduction in the percentage volume of debris to 16% and 11.3%, respectively. The closer the distance to the isthmus area was the larger the amount of accumulated debris regardless of the irrigating protocol used. Conclusions Through the present method, it was possible to calculate the volume of hard-tissue debris in the isthmuses and in the Root Canal Space. Free-software packages used for image reconstruction, registering, and analysis have shown to be promising for end-user application.
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micro computed tomography study of oval shaped Canals prepared with the self adjusting file reciproc waveone and protaper universal systems
Journal of Endodontics, 2013Co-Authors: Marco Aurelio Versiani, Graziela Bianchi Leoni, Liviu Steier, Gustavo Dedeus, Simone Tassani, Jesus Djalma Pecora, Manoel Damiao SousanetoAbstract:Abstract Introduction The newly developed single-file systems claimed to be able to prepare the Root Canal Space with only 1 instrument. The present study was designed to test the null hypothesis that there is no significant difference in the preparation of oval-shaped Root Canals using single- or multiple-file systems. Methods Seventy-two single-Rooted mandibular canines were matched based on similar morphologic dimensions of the Root Canal achieved in a micro–computed tomographic evaluation and assigned to 1 of 4 experimental groups ( n = 18) according to the preparation technique (ie, Self-Adjusting File [ReDent-Nova, Ra’anana, Israel], WaveOne [Dentsply Maillefer, Ballaigues, Switzerland], Reciproc [VDW, Munich, Germany], and ProTaper Universal [Dentsply Maillefer] systems). Changes in the 2- and 3-dimensional geometric parameters were compared with preoperative values using analysis of variance and the post hoc Tukey test between groups and the paired sample t test within groups (α = 0.05). Results Preparation significantly increased the analyzed parameters; the outline of the Canals was larger and showed a smooth taper in all groups. Untouched areas occurred mainly on the lingual side of the middle third of the Canal. Overall, a comparison between groups revealed that SAF presented the lowest, whereas WaveOne and ProTaper Universal showed the highest mean increase in most of the analyzed parameters ( P Conclusions All systems performed similarly in terms of the amount of touched dentin walls. Neither technique was capable of completely preparing the oval-shaped Root Canals.
