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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Avaliação do desvio apical em molares inferiores após emprego dos sistemas Waveone® e Reciproc® por meio da tomografia computadorizada

Meireles, Daniely Amorim de 24 January 2014 (has links)
Submitted by Geyciane Santos (geyciane_thamires@hotmail.com) on 2015-06-11T14:42:40Z No. of bitstreams: 1 Dissertação -Daniely Amorim de Meireles.pdf: 13588025 bytes, checksum: 907abba7b19235b598e2c627358f9b82 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-11T18:30:35Z (GMT) No. of bitstreams: 1 Dissertação -Daniely Amorim de Meireles.pdf: 13588025 bytes, checksum: 907abba7b19235b598e2c627358f9b82 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-11T20:33:35Z (GMT) No. of bitstreams: 1 Dissertação -Daniely Amorim de Meireles.pdf: 13588025 bytes, checksum: 907abba7b19235b598e2c627358f9b82 (MD5) / Made available in DSpace on 2015-06-11T20:33:35Z (GMT). No. of bitstreams: 1 Dissertação -Daniely Amorim de Meireles.pdf: 13588025 bytes, checksum: 907abba7b19235b598e2c627358f9b82 (MD5) Previous issue date: 2014-01-24 / FAPEAM - Fundação de Amparo à Pesquisa do Estado do Amazonas / The aim of this study was to evaluate, by means of tomographic exam, the occurrence and direction of apical deviation, capacity of centralization and percentage of area after root canal instrumentation with the Reciproc® and WaveOne® systems. Twenty-six mandibular molars with a degree of curvature of 20°≤40° and radius ≤10 mm, root length of 16 mm, apical diameter with reference to file K #15 and independent foramina were used. After embedment in self-polymerizing acrylic resin, the teeth were randomly distributed into two groups (n=13): WOG system – biomechanical preparation of mesial canals with WaveOne® and RG systems - biomechanical preparation of mesial canals with Reciproc® system. The apical deviation and its direction were evaluated using the formula D=(X1-X2)-(Y1-Y2). The capacity of centralization was analyzed by means of the formula CC=(X1-X2/Y1–Y2 or Y1– Y2/X1-X2), and the percentage increase in area was calculated from the difference between the area of the instrumented canal and that of the non-instrumented canal. RG presented the highest apical deviation values, however without statistically significant difference in comparison with WOG (P > .05). Both systems showed greater tendency towards transport in the mesial direction. None of the groups presented perfect centralization, with statistically similar values (p = 0.05). While the percentage increase in post instrumentation area presented no significant difference between the groups (P >.05). Both systems promoted minimal alteration in the root canal morphology. / O objetivo deste estudo foi avaliar por meio de exame tomográfico a ocorrência e direção do desvio apical, a capacidade de centralização e a porcentagem de aumento de área após instrumentação de canais radiculares com sistemas do Grupo Reciproc® (GR) e do Grupo WaveOne® (GWO). Vinte e seis molares inferiores com grau de curvatura de 20°≤40° e raio ≤10 mm, comprimento radicular de 16 mm, diâmetro apical referente a lima K #15 e forames independentes foram utilizados. Após inclusão em resina acrílica autopolimerizável, os dentes foram separados aleatoriamente em dois grupos (n=13): GWO - preparo biomecânico dos canais mesiais com sistema WaveOne® e GR - preparo biomecânico dos canais mesiais com sistema Reciproc®. O desvio apical e a sua direção foram avaliados a partir da fórmula D=(X1-X2)-(Y1-Y2). A capacidade de centralização foi analisada por meio da fórmula CC=(X1-X2/Y1–Y2 ou Y1–Y2/X1-X2), e o aumento percentual da área foi calculado a partir da diferença entre a área do canal instrumentado e não instrumentado. GR apresentou os maiores valores de desvio apical, no entanto, sem diferença estatisticamente significante em relação a GWO (P > .05). Ambos os sistemas proporcionaram maior tendência de transporte no sentido mesial. Ambos os grupos não apresentaram perfeita centralização, com valores similares estatisticamente (P >.05). Já o aumento percentual da área pós-instrumentação não apresentou diferença significante entre os grupos (P > .05). Ambos os sistemas promoveram alteração mínima da morfologia do canal radicular.
2

Comparative Analysis of WaveOne and LightSpeed LSX for the Residual Dentin Thickness of the Bifurcated Maxillary First Premolar Buccal Root Utilizing Limited Field Cone Beam Computed Tomography

Sarao, Manpreet Singh 02 May 2013 (has links)
The purpose of this study was to compare the thickness of dentin removed from the buccal root of bifurcated maxillary first premolars (BMFP) in the area of furcation groove after instrumentation with WaveOne and LightSpeed LSX files utilizing limited field cone beam computerized tomography. All data was analyzed using repeated-measured mixed-model ANOVA and differences were described using Tukey’s multiple comparison procedure. The thickness of dentin removed with LightSpeed LSX files (0.1 mm) was significantly less than the thickness of dentin removed with WaveOne files (0.2 mm). To conclude, LSX files remove a more predictable and consistent thickness of dentin from the buccal root of BMFP, irrespective of the pre-instrumentation thickness of dentin and the file size when compared to WO files that remove a more variable thickness of dentin.
3

The influence of glide path preparation on the failure rate of nickel-titanium reciprocating instruments

Jonker, Casper Hendrik January 2013 (has links)
Introduction: The aim of this in vitro study was to determine the influence of two glide path preparation methods on the fracture rate of the Primary 25/08 WaveOne reciprocating instrument. The number of simulator Endo-Training-Blocks in each group were calculated at the time of instrument fracture and compared to determine the influence of glide path preparation on the failure rate of the Primary 25/08 WaveOne reciprocating instrument. Preparation times for different glide path methods and total time for root canal preparation, with or without glide path, was also calculated. Materials and Methods: Simulator Endo-Training-Blocks (n = 300) were selected and randomly divided into 3 groups (n = 100). The 3 groups were then sub-divided into 5 smaller groups (n = 20). Root canal preparation was done with new primary 25/08 WaveOne instruments allocated to each group (5 in total for each group, 1 for each sub-group) following different methods for glide path preparation. Group 1: no glide path (control); Group 2: glide path preparation with stainless-steel hand files (size 10 K-File followed by size 15 K-File and finally size 20 K-File until loose fitting); and Group 3: glide path preparation with rotary PathFiles (size 10 K-File until loose fitting followed by PathFile no.1 (ISO 13 tip), PathFile no.2 (ISO 16 tip) and finally PathFile no. 3 (ISO 19 tip)). The Primary 25/08 WaveOne reciprocating instrument was used with the WaveOne endodontic motor in “WaveOne All “mode with a brushing motion on the outstroke. Simulated root canals were irrigated with sterile water and Glyde was used as lubricating agent. The outcome was measured by recording how many simulators could be prepared with one instrument before instrument breakage occurred. The preparation protocol was repeated 5 times. The time it took to prepare the glide path and the total preparation time was also calculated. The data of the different parts of the project were collected and statistically analysed using the ANOVA / Bonferroni test. Results: Glide path preparation with PathFiles was significantly faster (13.3 s ± 2.60 s) than with hand files (25.1 s ± 1.70 s) (P < 0.001). The highest number of simulators could be prepared after glide path preparation was performed with PathFiles (19.2 ± 0.84) (P < 0.001). Pairwise comparisons at the Bonferroni adjusted significance level of 0.017 demonstrated that there were statistical significant differences (P < 0.001) when PathFiles (19.2 ± 0.84) and hand files (17.6 ±1.14) were compared to the no glide path group (7.4 ± 0.89). There was no statistical significant difference between PathFiles and hand files groups. Total Preparation time was significantly shorter (P < 0.001) when an initial glide path was prepared with PathFiles (12.7 ± 0.22 s). The longest preparation time (P < 0.001) was calculated in group 1 where no glide path (21.2 ± 0.20 s) was present and the Endo-Training-Blocks were left undisturbed. Conclusion: Initial glide path preparation with PathFiles resulted in shorter preparation time (glide path and total preparation) and allowed a higher number of simulators prepared before failure of the WaveOne instrument. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Odontology / unrestricted
4

Utilization of a new web-based application for case difficulty assessment as a predictor for procedural errors in nonsurgical root canal treatment

Hasanat, Watraat Unmona 01 January 2021 (has links)
Introduction: There are currently no established guidelines to determine which cases general practitioners should refer to an endodontist for root canal treatment. The American Association of Endodontists (AAE) has developed the EndoCase mobile application (ECA), which utilizes either a full or abridged rubric to assign case difficulty level and provide referral guidelines to general practitioners and dental students. Objective: The objective of this study was to determine whether the abridged criteria of the EndoCase application can help predict the incidence of procedural errors in nonsurgical root canal treatment of mandibular molars in an undergraduate dental clinic based on the difficulty level. Methods: A list of patients who received primary root canal treatment on mandibular first molars in the undergraduate dental clinic from 2015-2020 was obtained. Ninety patients qualified for inclusion. Case difficulty level was assessed using the ECA by three providers with differing levels of experience. Incidence of procedural errors was determined from post-operative radiographs by two calibrated independent observers. Results: The most common endodontic mishaps were errors during access cavity preparation followed by the presence of voids in the root filling, with an incidence of 54.4% and 45.6%, respectively. There were no significant differences regarding case difficulty level and the incidence of total procedural errors nor number of treatment visits. Of the individual error types, the presence of obturation >2mm short of the radiographic apex was weakly correlated with case difficulty level (r = 0.226, pConclusion: There is minimal correlation between the difficulty level of mandibular molars determined by the ECA and the number of treatment visits or overall incidence of procedural errors.

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