RESUMO
BACKGROUND: Paediatric rotary file systems have recently been developed for primary teeth use. AIM: To study the cleaning efficacies of two paediatric rotary endodontic files, the Prime PedoTM, and the Kedo-SG BlueTM against the standard H files. DESIGN: This in vitro study included 54 freshly extracted primary molars, which were randomised into three groups (n = 18 each) and were prepared using either Kedo-SG BlueTM, Prime PedoTM or hand H files after injecting methylene blue dye into the canals. Pre- and post-operative cone beam computerised tomography (CBCT) was performed to assess change in root canal volumes. Methylene blue dye removal from canals was assessed using stereomicroscopy, and canal cleanliness was examined by scanning electron microscopy (SEM). RESULTS: Both Prime PedoTM and Kedo-SG BlueTM files reduced significantly less dentine when compared with conventional hand filing with Prime PedoTM removing the least amount of dentine. No significant difference was found in median SEM scores among the groups in the cervical, middle and apical thirds of the roots. Stereomicroscopic assessment of root canal cleanliness using dye removal technique shows a statistically significant difference existing between Kedo-SG BlueTM and hand H files groups. CONCLUSION: Prime PedoTM removed the least amount of dentine. Kedo-SG BlueTM performed significantly better than conventional hand filing with H files when the root canal cleanliness was assessed.
Assuntos
Cavidade Pulpar , Microscopia Eletrônica de Varredura , Dente Molar , Preparo de Canal Radicular , Dente Decíduo , Humanos , Preparo de Canal Radicular/instrumentação , Preparo de Canal Radicular/métodos , Técnicas In Vitro , Instrumentos Odontológicos , Tomografia Computadorizada de Feixe Cônico , Desenho de Equipamento , Azul de MetilenoRESUMO
OBJECTIVES: The aims of this study are (i) to propose specific selection criteria related to NiTi instruments for dental practitioners and (ii) to objectively assess the NiTi instruments. MATERIALS AND METHODS: The steps of the methodology are as follows: Step 1: "Delphi method" was employed to reach a consensus on criteria defined according to the literature review and a group of panelists. Step 2: "Smart pairwise comparisons" were employed to rank the proposed criteria. Step 3: "Borda voting" was employed to determine the weights of the proposed criteria. Step 4: To determine assessment scores, "Simple Additive Weighting" was employed. Step 5: Reliability and validity checks were made by "simulation." RESULTS: Specific criteria classified under dimensions were proposed and weighted for the NiTi instrument assessment. In this context, an assessment model was proposed and validated. CONCLUSIONS: The proposed assessment model for NiTi instruments could aid to make the decision-making process as systematic, transparent, and reproducible as possible not only for dental practitioners but also for healthcare professionals. Also, this proposed model can represent a reference framework for further MCDM studies which can rank or classify materials in medical science. CLINICAL RELEVANCE: The model proposed in this study can be used to aid decision-making in clinical practice by means assessing the NiTi instrumentation system alternatives for practitioners.
Assuntos
Instrumentos Odontológicos , Níquel , Ligas Dentárias , Materiais Dentários , Odontólogos , Desenho de Equipamento , Humanos , Teste de Materiais , Papel Profissional , Reprodutibilidade dos Testes , Preparo de Canal Radicular , TitânioRESUMO
INTRODUCTION: The aim of this study was to conduct a micro-computed tomographic assessment of the effectiveness of 3 supplementary cleaning techniques in reducing the residual volume of gutta-percha and a bioceramic sealer after performing endodontic retreatment procedures in teeth with oval canals. METHODS: Thirty-six mandibular premolars were instrumented with the ProTaper Next system (instruments X1-X3; Dentsply Maillefer, Ballaigues, Switzerland) and filled with gutta-percha and Bio-C Sealer (Angelus, Londrina, PR, Brazil) using the single-cone technique. The teeth were reinstrumented with the Reciproc R40 instrument (VDW, Munich, Germany) and divided into 3 groups according to the supplementary cleaning technique used (n = 12): ultrasonic-assisted irrigation (UAI), EndoActivator (Dentsply Tulsa Dental Specialties, Tulsa, OK) irrigation (EAI), or the XP-endo Finisher R system (XPR; FKG Dentaire, La Chaux-de-Fonds, Switzerland). Micro-computed tomographic imaging was used to quantify the residual volume of filling material. One-way analysis of variance complemented by the Tukey test was used to perform the statistical analysis (P < .05). RESULTS: Significant reductions were obtained in the residual filling material after supplementary cleaning (P < .05). XPR (47.5%) led to significantly greater (P < .05) filling material removal than UAI (16.6%) or EAI (22.6%). The removal values of the 2 latter systems were not significantly different. CONCLUSIONS: XPR was more effective than UAI and EAI in removing filling material in mandibular premolars with oval canals. None of the tested supplementary cleaning techniques completely removed the residual filling material.
Assuntos
Guta-Percha , Materiais Restauradores do Canal Radicular , Brasil , Instrumentos Odontológicos , Cavidade Pulpar , Retratamento , Obturação do Canal Radicular , Preparo de Canal Radicular , Microtomografia por Raio-XRESUMO
BACKGROUND: To introduce a new method for measurement of surface roughness of the endodontic instrument, before and after instrumentation, using the Field Emission Scanning Electronic Microscope (FE-SEM) combined with the ImageJ software. METHODS: Twenty J-shape resin blocks were divided into two groups, ten blocks of each group. Simulated root canal inside the resin block was 16 mm length, 600 angle of curvature, and radius of 4.5 mm. Ten WaveOne Gold Primary and 10 Reciproc Blue R25 instruments were used for root canal instrumentation. The instruments were scanned before and after instrumentation with special molds made to ensure the same areas at the point located 3 mm from the tips of the instruments using the FE-SEM. These scanned images were analyzed using the ImageJ. The arithmetical mean roughness (Ra), root mean square roughness (Rq), and the average distance between the highest peak and lowest valley in each sampling length (Rz) were calculated by ImageJ for quantitative analyses. The paired-t test was performed to analyze the data using the SPSS 22.0 at the significance of .05. RESULTS: Almost all surface roughness values were decreased. However, these decreases were not statistically significant (P > .05). CONCLUSIONS: The FE-SEM combined with the ImageJ was the reliable and appropriate modality for measurement surface roughness of instruments.
Assuntos
Níquel , Titânio , Ligas Dentárias , Instrumentos Odontológicos , Eletrônica , Desenho de Equipamento , Teste de Materiais , Preparo de Canal RadicularRESUMO
OBJECTIVES: The purpose of the study was to examine hearing thresholds among dental personnel. The secondary aim was to evaluate sound levels among dental equipment that dental personnel are exposed to. METHODS: Two hundred forty-four dentists, dental technicians, dental assistants, and dental students participated. Sixty-two participated as a control group. Audiological thresholds for the test groups were compared to the control group. All participants were from Jordan University Hospital. Participants completed a questionnaire in addition to their audiometric testing. Otoscopy, tympanometry, and pure tone audiometry were included in their assessment. Three-factor ANOVA and t tests were utilized to assess the statistical differences of hearing thresholds among the groups and between the two ears. Pearson correlation test was used to assess the effect of age, experience, and duration of exposure on the degree of hearing loss in the test groups for both ears. RESULTS: The authors reported statistically significant differences among hearing thresholds between the control group and others. Left hearing thresholds were noted to be significantly poorer in the left versus right ear at 1000, 2000, 4000, and 8000 Hz in dental assistants. The authors also reported a significant relationship between the degree of hearing impairment among dental assistants and the daily duration of exposure to dental occupational noise, followed by age. CONCLUSION: Hearing impairment was higher among dental professionals than the control group and especially among dental assistants and technicians. The authors recommended screening guidelines and adapting hearing protection methods for dental professionals and particularly for dental assistants and technicians.
Assuntos
Instrumentos Odontológicos/efeitos adversos , Recursos Humanos em Odontologia , Odontólogos , Perda Auditiva Provocada por Ruído/etiologia , Ruído Ocupacional/efeitos adversos , Doenças Profissionais/etiologia , Adulto , Audiometria de Tons Puros , Limiar Auditivo , Feminino , Humanos , Masculino , Adulto JovemRESUMO
INTRODUCTION: The purpose of this study was to evaluate the ability of the XP-endo Shaper instrument (FKG Dentaire, La Chaux-de-Fonds, Switzerland) during the removal of root fillings from oval-shaped canals. M-Wire Reciproc and Reciproc Blue systems (VDW, Munich, Germany) were used as reference instruments for comparison, and micro-computed technology was used as an analytical tool. METHODS: Thirty mandibular incisors with oval-shaped canals were matched based on similar anatomic features of the canal (eg, volume, aspect ratio, and 3-dimensional configuration) after scanning procedures. The canals were prepared with M-Wire Reciproc R25 instruments and filled with gutta-percha and AH Plus sealer (Dentsply DeTrey, Konstanz, Germany) using the continuous wave of condensation technique. Then, the sample was allocated into 3 experimental groups (n = 10) according to the retreatment protocol used: M-Wire Reciproc, Reciproc Blue, and XP-endo Shaper. M-Wire Reciproc R25, Reciproc Blue R25, and XP-endo Shaper instruments were used to remove the root fillings. Apical enlargement was performed with M-Wire Reciproc R40, Reciproc Blue R40, and BioRace BR5 (FKG Dentaire) instruments. Each sample was scanned after each endodontic procedure. The volume of remaining root filling material was quantified before and after apical enlargement. The percentage volumes of root filling reduction in relation to the instrumented canals at both time points (before and after apical enlargement) were calculated and considered for statistical analysis. Data were analyzed statistically with a significance level of 5%. RESULTS: Reciproc Blue presented significantly lower removal of filling material compared with the XP-endo Shaper (Tukey test, P < .05). No difference was detected either between M-Wire Reciproc and Reciproc Blue (Tukey test, P > .05) or M-Wire Reciproc and XP-endo Shaper (Tukey, P > .05). The increase of apical enlargement significantly improved the removal of root fillings from the root canals (P < .05); this effect was similar for all systems (time point × file system, P > .05). CONCLUSIONS: The XP-endo Shaper instrument showed a higher percentage of root filling removal, but no differences were observed comparing M-Wire Reciproc with the XP-endo Shaper or Reciproc Blue. The increase of apical enlargement improved the removal of root fillings in all groups. None of them was able to render root canals completely free from root fillings.
Assuntos
Materiais Restauradores do Canal Radicular , Obturação do Canal Radicular , Instrumentos Odontológicos , Cavidade Pulpar , Alemanha , Guta-Percha , Humanos , Retratamento , Preparo de Canal Radicular , Microtomografia por Raio-XRESUMO
DRACES [Departamento de Regulación, Acreditación y Control de Establecimientos de Salud] Este documento tiene como objeto: "la Regulación, Autorización y Control de las Clínicas Dentales, en concordancia con el Reglamento para la Regulación, Autorización, Acreditación y Control de Establecimientos de Atención para la Salud, Acuerdo Gubernativo 376-2007." Es de carácter obligatorio, por lo que se aplica tanto al sector público, privado, social o subsector de la seguridad social, en todo el territorio nacional. Contiene además, las definiciones de los conceptos relacionados al tema principal, además de la infraestructura que deberá tener cada clínica, incluidos el equipo y recurso humano y técnico.
Assuntos
Humanos , Masculino , Feminino , Consultórios Odontológicos/legislação & jurisprudência , Consultórios Odontológicos/organização & administração , Contenção de Riscos Biológicos/normas , Equipamentos Odontológicos , Instrumentos Odontológicos/normas , Recursos Humanos em Odontologia/normas , GuatemalaRESUMO
OBJECTIVE: To determine the effectiveness of different pre-cleaning methods by determining frequency and site of contamination on the sterilised dental burs using Phloxine B dye. METHODS: The in-vitro experimental study was conducted from June to August 2017 at dental clinics of Aga Khan University Hospital Karachi. Diamond dental burs were selected and divided into two control and four test groups. The two control groups were classified as Negative (new burs) and Positive (used contaminated). The four test groups were classified as Manual (Group-1), Ultrasonic (Group-2), Manual + Enzyme (Group-3) and Manual + Ultrasonic (Group-4). Phloxine B dye was used to determine the contamination. The images of the burs were taken and enlarged at 15X before subjected to visual assessment. Association between contamination and pre-cleaning methods were determined. Data was analysed using SPSS version 22. RESULTS: A total of 210 burs were selected for the study which were divided in 6 groups of 35(16.66%) each. One (2.8%) bur in negative control group and all burs in positive control group showed contamination. In test groups, 27(77.1%), 29(82.8%), 27(77.1%) and 24(68.5%) burs showed contamination in groups 1, 2, 3 and 4, respectively. There was no association between type of pre-cleaning method with the frequency of contamination (p =0.57). The head of bur was the most frequently contaminated site (p < 0.003). CONCLUSIONS: None of the pre-cleaning method was found to be effective. Head of bur was the most frequently contaminated site.
Assuntos
Instrumentos Odontológicos , Contaminação de Equipamentos , Esterilização , Azul de Eosina I , Corantes Fluorescentes , Humanos , Paquistão , Esterilização/métodosRESUMO
OBJECTIVES: : We compared apical transportation in the WaveOne and ProTaper Next systems, which are rotary nickel-titanium systems with reciprocating and continuous rotation movements, respectively, using manual measurements obtained from resin blocks with simulated root canals and double digital radiographs of extracted teeth. MATERIALS AND METHODS: : We used 30 resin blocks with simulated root canals and 30 extracted teeth for this study. The same endodontist performed root canal shaping using the WaveOne or ProTaper Next system. We assessed apical transportation by measuring the amounts (in mm) of material lost 1 mm from the apical foramen in the resin blocks and by using double digital radiography for the extracted teeth. Significant differences between groups were assessed using t-tests. P < 0.05 was considered statistically significant. RESULTS: : The amount of apical transportation differed significantly between the two systems when resin blocks were used for assessment (P < 0.05), but there were no significant differences when extracted teeth were used (P < 0.05). CONCLUSIONS: In the current study, there was no significant difference in apical transportation between natural teeth prepared using WaveOne and those prepared using ProTaper Next. However, significant differences were observed between the two systems with resin blocks. These findings indicate that the use of resin blocks is not an accurate method for apical transportation evaluation.
Assuntos
Cavidade Pulpar/anatomia & histologia , Cavidade Pulpar/cirurgia , Dente Molar/cirurgia , Níquel/química , Preparo de Canal Radicular/instrumentação , Tratamento do Canal Radicular/instrumentação , Ligas , Instrumentos Odontológicos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Dente Molar/diagnóstico por imagem , Preparo de Canal Radicular/métodos , Tratamento do Canal Radicular/métodos , Rotação , Titânio/química , Ápice Dentário/anatomia & histologia , Extração Dentária , Meios de TransporteRESUMO
BACKGROUND: Gingivectomy is a procedure often performed in everyday clinical practice using numerous instruments. AIM: To evaluate and compare the gingival cut surface after gingivectomy with 6 different surgical instruments - a surgical scalpel, an Er:YAG laser, a CO2 laser, a ceramic bur, an electrocautery device, and a diode laser. MATERIALS AND METHODS: Gingivectomy using the above listed instruments was performed in 18 patients. The histological samples excised with a surgical scalpel were assigned as a control group and the other five types - as test groups. The following histological parameters were measured: coagulation layer thickness (in µm); presence or absence of a microscopic rupture and presence or absence of hemostasis in-depth. RESULTS: The best instrument of the above listed ones which demonstrated excellent results is the CO2 laser. The Er:YAG laser has a thin coagulation layer and lack of hemostasis in-depth. The diode laser has the widest coagulation layer which is an advantage from a clinical point of view. Electrocautery proved to be as effective as the diode laser, but it should not be used around metal restorations. The ceramic bur has less pronounced hemostasis in-depth. CONCLUSIONS: Modern dentistry uses a wide variety of methods that are designed to be applied in everyday practice. Good knowledge of the ways to use them, their advantages and disadvantages is essential to obtaining the optimal result depending on the clinical case.
Assuntos
Gengiva/patologia , Gengiva/cirurgia , Gengivectomia/métodos , Terapia a Laser/métodos , Adolescente , Adulto , Cerâmica , Instrumentos Odontológicos , Eletrocoagulação/efeitos adversos , Eletrocoagulação/instrumentação , Feminino , Gengiva/lesões , Gengivectomia/efeitos adversos , Gengivectomia/instrumentação , Hemostasia Cirúrgica/efeitos adversos , Hemostasia Cirúrgica/instrumentação , Hemostasia Cirúrgica/métodos , Humanos , Terapia a Laser/efeitos adversos , Terapia a Laser/instrumentação , Lasers de Gás/efeitos adversos , Lasers de Gás/uso terapêutico , Lasers Semicondutores/efeitos adversos , Lasers Semicondutores/uso terapêutico , Lasers de Estado Sólido/efeitos adversos , Lasers de Estado Sólido/uso terapêutico , Masculino , Adulto JovemRESUMO
The aim of this study was to retrospectively evaluate the periodontal response of periodontally healthy teeth prosthetically restored using a featheredge finish line preparation combined with a light rotary curettage (gingittage). A total of 137 restored teeth were included in the study. Mean follow-up time was 18.2 months (range: 6 to 60 months). Bleeding on probing was noted in 18% of cases, while the Plaque Index was found to be 11%. The probing depth in 99.4% of cases was ≤ 3 mm. In only 7 cases (5.1%), a slight restoration margin exposure was recorded. Although randomized controlled studies with longer follow-up are advocated, the present investigation seems to suggest that this protocol is a viable procedure.
Assuntos
Prótese Dentária , Periodonto , Curetagem Subgengival , Adulto , Idoso , Idoso de 80 Anos ou mais , Instrumentos Odontológicos , Índice de Placa Dentária , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice Periodontal , Estudos RetrospectivosRESUMO
BACKGROUND: Cleaning and shaping of the pulp canal is one of the most important steps of endodontic therapy. Serious complications occur by the apical extrusion of bacteria during the instrumentation procedures. Both crown-down (CD) and full-length linear motion (FM) techniques are routinely used as a component of taper rotary instrument procedures for achievement of thorough cleaning and shaping of the pulp canal space. Hence, we aimed for this study to assess the change in the amount of apically extruded bacteria using CD and FM instrumentation techniques produced by differences in taper between the instruments used during biomechanical preparation of root canals. MATERIALS AND METHODS: The present study included assessments of 132 extracted maxillary central incisor teeth. To achieve a uniform teeth length of 21 mm, the height of the tooth crown was reduced for preserving the coronal portion of teeth. A modified glass vial model was constructed for the estimation of amount of bacterial extrusion through the apical region. For filling of each pulp canal specimen, 20 mL of Enterococcus faecalis suspension was used followed by the use of a number 10 K-file for carrying the bacteria down the lengths of pulp canals. All the contaminated teeth specimens were divided into six study groups with groups I to III containing specimens prepared in the CD manner, while groups IV to VI contained specimens prepared in the FM manner. Six teeth were taken as negative control with three specimens with each technique, and another six specimens were taken as positive controls. Cultivable bacterial counts were determined by evaluating 100 mL saline solution from each vial followed by its inoculation on blood agar. All the colony-forming unit (CFU) values were log-transformed (base 10), and the results were analyzed by Statistical Package for the Social Sciences software. RESULTS: A significantly lower quantity of CFU values was observed during CD instrumentation procedures with 0.02 files in comparison with all other study groups. However, while comparing both the instrumentation procedures when different taper files, other than 0.02 taper, were used for biomechanical preparation of root canal, nonsignificant results were obtained. CONCLUSION: With 0.02 taper preparations, significantly less amount of extrusion of bacteria is associated when done with CD technique. CLINICAL SIGNIFICANCE: No change in the amount of apical extrusion of bacteria will be seen by changing the type of instrumentation procedures. Amount of bacteria extruded can be minimized using 0.02 taper. Key words: Bacteria, Instrumentation, Taper.
Assuntos
Preparo de Canal Radicular/instrumentação , Preparo de Canal Radicular/métodos , Ápice Dentário/microbiologia , Carga Bacteriana , Instrumentos Odontológicos , Estudos de Avaliação como Assunto , Humanos , Técnicas In VitroRESUMO
BACKGROUND: Dentists have a high prevalence of musculoskeletal (MS) pain, which is the most common symptom associated with work-related musculoskeletal disorders (WMSDs). To overcome this problem, identification of the risk factors and preventive measures for MS pain are of paramount importance to dentists in order to improve their quality of life and work. OBJECTIVES: The aims of this study were to recognize the risk factors for MS pain and their impact on dental work, as well as to identify preventive measures of MS pain among dentists. METHODS: Self-reporting questionnaire consisting of 78 questions was exclusively developed for the study and sent to 500 working active dentists in Serbia. RESULTS: Response rate was 71.2% (356 dentists). The prevalence of MS pain was 82.6% among dentists. The main risk factors for MS pain were advanced age, female dentists, presence of chronic diseases, long working hours, and high frequency of treated patients. The most effective preventive measures in preventing MS pain were massage treatments and physical activities. Followed by use of ergonomically designed equipment, correct and dynamic working positions, and an adequate workflow organization. CONCLUSION: The risk factors for MS pain and their impact on dental work should widely be disseminated among dentists. Importantly, proper implementation in everyday life of adequate preventive measures is essential for preventing MS pain and development of WMSDs.
Assuntos
Odontólogos/estatística & dados numéricos , Dor Musculoesquelética/epidemiologia , Doenças Profissionais/epidemiologia , Adulto , Fatores Etários , Instrumentos Odontológicos , Odontologia , Ergonomia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor Musculoesquelética/prevenção & controle , Doenças Profissionais/prevenção & controle , Fatores de Risco , Sérvia , Fatores Sexuais , Inquéritos e Questionários , Carga de TrabalhoRESUMO
BACKGROUND AND OBJECTIVES: Conservative caries removal has become an integral part of minimally invasive dentistry (MID). Polymer burs and chemomechanical caries removal are two feasible methods of MID. The objective of this study was to assess and compare the efficacy of polymer bur and chemomechanical caries removal agent clinically and microbiologically for selective removal of infected dentin. METHODS: A total of fifty primary second molars with occlusal decay involving dentin were selected from 25 patients aged between 5 and 9 years. They were randomly allocated to Group A (polymer bur group) and Group B (Carie-Care group) for caries removal. Completeness of caries excavation was assessed clinically with the application of caries detector dye. Dentinal samples were collected before and after caries removal and cultured in Luria-Bertani Agar, and total viable count was assessed. All the teeth after caries excavation were restored with Type 2 glass ionomer cement. The data obtained was tabulated and statistically analyzed using paired t-test and Chi-square test. RESULTS: There was a statistically significant reduction in the mean microbial count before and after treatment in polymer bur group and Carie-Care group. The reduction in mean microbial count was found significantly higher in polymer bur group compared to Carie-Care group. There was no significant association was observed between the two groups when efficacy was assessed clinically. CONCLUSIONS: Both polymer bur and Carie-Care were efficient caries removal agents when assessed clinically and microbiologically. Polymer bur was found to be more effective than Carie-Care when assessed microbiologically.
Assuntos
Carica , Cárie Dentária/terapia , Preparo da Cavidade Dentária/métodos , Instrumentos Odontológicos , Extratos Vegetais/uso terapêutico , Criança , Pré-Escolar , Preparo da Cavidade Dentária/instrumentação , Terapia Enzimática , Cimentos de Ionômeros de Vidro , Humanos , Dente Molar , Polímeros , Dente DecíduoRESUMO
AIM: To describe a new method for the assessment of nanoscale alterations in the surface topography of nickel-titanium endodontic instruments using a high-resolution optical method and to verify the accuracy of the technique. METHODOLOGY: Noncontact three-dimensional optical profilometry was used to evaluate defects on a size 25, .08 taper reciprocating instrument (WaveOne® ), which was subjected to a cyclic fatigue test in a simulated root canal in a clear resin block. For the investigation, an original procedure was established for the analysis of similar areas located 3 mm from the tip of the instrument before and after canal preparation to enable the repeatability and reproducibility of the measurements with precision. All observations and analysis were taken in areas measuring 210 × 210 µm provided by the software of the equipment. RESULTS: The three-dimensional high-resolution image analysis showed clear alterations in the surface topography of the examined cutting blade and flute of the instrument, before and after use, with the presence of surface irregularities such as deformations, debris, grooves, cracks, steps and microcavities. CONCLUSIONS: Optical profilometry provided accurate qualitative nanoscale evaluation of similar surfaces before and after the fatigue test. The stability and repeatability of the technique enables a more comprehensive understanding of the effects of wear on the surface of endodontic instruments.
Assuntos
Ligas , Instrumentos Odontológicos , Teste de Materiais/métodos , Endodontia/instrumentação , Imageamento Tridimensional , Propriedades de SuperfícieRESUMO
STATEMENT OF PROBLEM: Recently, zirconia removal diamond rotary instruments have become commercially available for efficient cutting of zirconia. However, research of cutting efficiency and the cutting characteristics of zirconia removal diamond rotary instruments is limited. PURPOSE: The purpose of this in vitro study was to assess and compare the cutting efficiency, durability, and diamond rotary instrument wear pattern of zirconia diamond removal rotary instruments with those of conventional diamond rotary instruments. In addition, the surface characteristics of the cut zirconia were assessed. MATERIAL AND METHODS: Block specimens of 3 mol% yttrium cation-doped tetragonal zirconia polycrystal were machined 10 times for 1 minute each using a high-speed handpiece with 6 types of diamond rotary instrument from 2 manufacturers at a constant force of 2 N (n=5). An electronic scale was used to measure the lost weight after each cut in order to evaluate the cutting efficiency. Field emission scanning electron microscopy was used to evaluate diamond rotary instrument wear patterns and machined zirconia block surface characteristics. Data were statistically analyzed using the Kruskal-Wallis test, followed by the Mann-Whitney U test (α=.05). RESULTS: Zirconia removal fine grit diamond rotary instruments showed cutting efficiency that was reduced compared with conventional fine grit diamond rotary instruments. Diamond grit fracture was the most dominant diamond rotary instrument wear pattern in all groups. All machined zirconia surfaces were primarily subjected to plastic deformation, which is evidence of ductile cutting. Zirconia blocks machined with zirconia removal fine grit diamond rotary instruments showed the least incidence of surface flaws. CONCLUSIONS: Although zirconia removal diamond rotary instruments did not show improved cutting efficiency compared with conventional diamond rotary instruments, the machined zirconia surface showed smoother furrows of plastic deformation and fewer surface flaws.
Assuntos
Instrumentos Odontológicos , Zircônio , Prótese Dentária , Diamante , Técnicas In Vitro , Microscopia Eletrônica de VarreduraRESUMO
The aim of this study was to evaluate the effects of preparation, filling removal material, reinstrumentation and reobturation of root canals with different Ni-Ti alloys in endodontic retreatment. Firstly, the selection and pairing of mesial root canals of mandibular molars (n = 45) were performed by computerized micro-tomography (micro-CT). After pairing, the specimens were divided into three groups (n = 15), instrumented with the Mtwo® (up to file 25.06), ProDesign Logic (25.06) and ProDesign R (25.06) systems. After this, the specimens were scanned again for root canal deviation analysis at 2, 4, 6, 8 and 10 mm from the apex and the volume increase of these root canals was evaluated through CTan Then, the root canals were filled with Endofill® with 0.1% rhodamine B and scanned in micro-CT once again. For the retreatment of the specimens, 3 groups were established according to the system used (Reciproc®, Hyflex® and ProDesign Duo Hybrid®). During the retreatment, the specimens were scanned in micro-CT in two more phases, after removal of filling material and after reinstrumentation of the root canals. All the images obtained previous and post-retreatment were compared to evaluate the capacity of removal filling material of each system through the volume of material remaining at 3mm in the apical third. Possible deviation of the root canal was assessed at 2, 4, 6, 8 and 10 mm from the apex. In addition, the times of preparation, removal filling material and reinstrumentation of these files were also evaluated. After the removal filling material and reinstrumentation of the root canals, they were refilled with AH Plus with 0.1% fluorescein. The specimens were sectioned crosswise into 2 mm slices to be analyzed by a confocal laser scanning microscope (CLSM) at 1, 3 and 5 mm from the apex, where the volume of material was evaluated through LAS X 3D and 2D software. The time of preparation, removal filling material and reinstrumentation of the root canals between the different systems was measured by a digital timer. The evaluation of canal volumetric increase and preparation time between Mtwo and ProDesign Logic systems were conducted using Student t-test analysis. Non-parametric Wilcoxon test was used to the intragroup comparison at the 2, 4, 6, 8 and 10 mm levels and non-parametric Mann-Whitney test was used to the comparison between groups in the root canal transportation in all sections of the root canal. The intra-group comparison regarding the presence or absence of root canal deviation after removal of root canal filling material and re-instrumentation was submitted to the parametric T-paired statistical test, since it had a normal distribution. The working time with the different alloys used to removal filling material an reinstrumentation was analyzed through parametric ANOVA e Tukey statistical test. The analysis of the remaining material present in the root canals was performed with nonparametric Kruskal-Wallis and Dunn tests. For the intra-group comparison between the different slices (1, 3 and 5 mm), the data were submitted to nonparametric Friedman and Dunn tests. The level of significance was established at 5% in all analysis. After the initial preparation of the root canals, the ProDesign Logic system proved to be faster than Mtwo system, with statistical difference between them (P <0.05). There was no statistical difference in root canal deviation after initial preparation and after retreatment (P> 0.05). In addition, the groups did not present a significant statistical difference to the volume increase of the root canals after the initial preparation or to the volume of filling material remaining after the retreatment (P> 0.05). The Reciproc system proved to be the fastest system for the removal filling material and reinstrumentation of the root canals (P <0.05). The present study demonstrated that the Prodesign Logic and Mtwo systems presented similar capacity of preparation of mesial root canals. The Reciproc, Hyflex and ProDesign Duo Hybrid systems are similar in the removal of filling material, preserving the original root canal shape in endodontic retreatment. However, Reciproc was the fastest compared to the other groups.(AU)
O presente trabalho teve como objetivo avaliar os efeitos decorrentes do preparo inicial, desobturação, reinstrumentação e reobturação de canais radiculares com diferentes ligas de Ni-Ti em casos de retratamento endodôntico. Primeiramente, foi realizado a seleção e o pareamento da anatomia de canais mesiais de primeiros molares inferiores (n=45) através de micro-tomografia computadorizada (micro-CT). Após o pareamento dos espécimes, os mesmos foram divididos em três grupos (n =15), instrumentados com os sistemas Mtwo® (até a lima 25.06), ProDesign Logic (25.06) e ProDesign R (25.06) sendo escaneados novamente para análise de desvio do canal radicular a 2, 4, 6, 8 e 10 mm, além do aumento de volume desses canais, avaliados através do CTan. Em seguida, os canais radiculares foram obturados com o cimento Endofill® acrescido de 0,1% de rodamina B e escaneados em micro-CT mais uma vez. Para o retratamento dos espécimes, foram estabelecidos 3 grupos, de acordo com o sistema utilizado (Reciproc®, Hyflex® e ProDesign Duo Híbrido®). Durante o retratamento, os espécimes foram escaneados em micro-CT em mais duas etapas, após a desobturação e a após a reinstrumentação dos canais. Todas as imagens obtidas referentes ao pré e pós retratamento foram confrontadas com o intuito de avaliar a capacidade de remoção de material obturador de cada sistema através do volume de material remanescente nos 3 mm apicais, além de avaliar possíveis desvios dos canais a 2, 4, 6, 8 e 10 mm do ápice. Foram avaliados também, o tempo efetivo de preparo, desobturação e de reinstrumentação desses instrumentos. Após a desobturação e reinstrumentação dos canais, os mesmos foram reobturados com cimento AH Plus acrescido de 0,1% de fluoresceína. Os espécimes foram seccionados transversalmente em fatias de 2 mm para serem analisados em microscópio confocal de varredura a laser (MCVL) a 1, 3 e 5 mm do ápice, onde foi avaliado, através do software LAS X 3D e 2D, o volume de material obturador antigo. O tempo de preparo, desobturação e reinstrumentação dos canais entre os diferentes sistemas foi marcado através de um cronômetro digital. A análise do aumento volumétrico e tempo de preparo entre os sistemas Mtwo e ProDesign Logic foi feita através do teste estatístico Student t. Para a análise do desvio do canal radicular após o preparo inicial, o teste não-paramétrico Wilcoxon foi utilizado para a comparação intra-grupos nos níveis a 2, 4, 6, 8 e 10 mm do ápice, enquanto o teste não-paramétrico Mann-Whitney foi utilizado para comparação entre os grupos nos mesmos níveis. Para a análise do desvio do canal radicular após a desobturação e reinstrumentação dos canais, os dados foram submetidos ao teste paramétrico T-pareado. O tempo de desobturação e reinstrumentação com os diferentes sistemas foi analisado através do teste ANOVA e Tukey. Os dados referentes ao remanescente de material obturador foram analisados através dos testes não-paramétrico Kruskal-Wallis e Dunn. Para a comparação intra-grupos entre os diferentes níveis (1, 3 e 5 mm) foram utilizados os testes não-paramétricos Friedman e Dunn. O nível de significância foi estabelecido a 5% em todas as análises. Após o preparo inicial dos canais, o sistema ProDesign Logic demonstrou ser mais rápido que o sistema Mtwo, havendo diferença estatística entre eles (P < 0.05). Não houve diferença estatística quanto ao desvio do canal radicular tanto após o preparo inicial quanto após o retratamento (P > 0.05). Além disso, os grupos também não apresentaram diferença estatística significante quanto ao aumento do volume dos canais após o preparo inicial, nem em relação ao volume de remanescente de material obturador após o retratamento (P > 0.05). O sistema Reciproc demonstrou ser o mais rápido dentre os sistemas quanto à desobturação e reinstrumentação dos canais (P < 0.05). O presente trabalho demonstrou que os sistemas Prodesign Logic and Mtwo apresentaram capacidade similar de preparo dos canais mesiais de molares inferiores. Os sistemas Reciproc, Hyflex e ProDesign Duo Híbrido são parecidos quanto à remoção de material obturador, preservando o formato original do canal em casos de retratamentos entodônticos. Entretanto, Reciproc foi o mais rápido comparado aos outros grupos.(AU)
Assuntos
Humanos , Instrumentos Odontológicos , Níquel/química , Retratamento/instrumentação , Obturação do Canal Radicular/instrumentação , Preparo de Canal Radicular/instrumentação , Titânio/química , Análise de Variância , Ligas Dentárias/química , Resinas Epóxi/química , Teste de Materiais , Reprodutibilidade dos Testes , Retratamento/métodos , Materiais Restauradores do Canal Radicular/química , Obturação do Canal Radicular/métodos , Preparo de Canal Radicular/métodos , Estatísticas não Paramétricas , Tomografia Computadorizada por Raios XRESUMO
The purpose of this study was to assess the ability of an off-centered rectangular design system [ProTaper Next (PTN)] to maintain the original profile of the root canal anatomy. To this end, ProTaper Universal (PTU), Reciproc (R) and WaveOne (WO) systems were used as reference techniques for comparison. Forty clear resin blocks with simulated curved root canals were randomly assigned to 4 groups (n = 10) according to the instrumentation system used: PTN, PTU, R and WO. Color stereomicroscopic images of each block were taken before and after instrumentation. All image processing and data analysis were performed with an open source program (Fiji v.1.47n). Evaluation of canal transportation was obtained for two independent regions: straight and curved portions. Univariate analysis of variance and Tukey's Honestly Significant Difference test were performed, and a cut-off for significance was set at α = 5%. Instrumentation systems significantly influenced canal transportation (p = 0.000). Overall, R induced significantly lower canal transportation compared with WO, PTN and PTU (p = 0.000). The curved portion displayed superior canal transportation compared to the straight one (p = 0.000). The significance of the difference among instrumentation systems varied according to the canal level evaluated (p = 0.000). In its straight portion, R and WO exhibited significantly lower transportation than PTN; whereas in the curved portion, R produced the lowest deviation. PTU exhibited the highest canal transportation at both levels. It can be concluded that PTN produced less canal transportation than PTU and WO; however, R exhibited better centering ability than PTN.