RESUMEN
AIM: To evaluate in a laboratory setting the performance of two reciprocating glide path systems, WaveOne Gold Glider (WO) and R-Pilot (RP), to create a glide path in mesial root canals of mandibular molars and to assess the torsional resistance of instruments after performing the glide path. METHODOLOGY: A total of 60 mesial root canals of extracted human mandibular molars were divided into two groups (n = 30) according to the glide path system to be used. The data from the volume of each canal, acquired by microcomputed tomography (micro-CT), were validated statistically for the anatomical pairing of the groups. Preparation time, frequency in gaining apical patency, plastic deformation rate of instruments, and canal transportation and centring ability were recorded and compared statistically. The torsional fatigue of the instruments after use was also evaluated. Data were analysed using Fisher's exact test and Mann-Whitney U-test with a 5% significance level. RESULTS: No significant differences were found between groups regarding the time required to perform the glide path, the frequency distributions of the canals classified as patent and the instruments with plastic deformation after use (P > 0.05). No significant differences were found between groups regarding the degree of canal transportation and centring ability at the cervical, middle and apical thirds (P > 0.05). The RP groups had significantly greater maximum torsional strength values compared with the WO groups (P < 0.05). The used WO group had greater angular deflection to fracture when compared to the new WO group (P < 0.05). A significant difference was also found in the percentage of loss of angular deflection in a comparison of the WO group with the RP group (P < 0.05). CONCLUSIONS: The WO and RP instruments performed the same in terms of preparation time, plastic deformation, gaining apical patency, degree of canal transportation and centring ability. The RP instruments had greater torsional strength, less angular deflection and lower percentage of loss in angular deflection than the WO. The used WO group had the greatest angular deflection values.
Asunto(s)
Cavidad Pulpar , Laboratorios , Instrumentos Dentales , Cavidad Pulpar/diagnóstico por imagen , Diseño de Equipo , Humanos , Diente Molar/diagnóstico por imagen , Diente Molar/cirugía , Preparación del Conducto Radicular , Estadísticas no Paramétricas , Titanio , Microtomografía por Rayos XRESUMEN
AIM: This prospective clinical study evaluated the incidence of instrument fracture observed after single-file root canal treatment of molars using WaveOne Gold instruments. METHODOLOGY: Three standardized, experienced and calibrated specialists treated 750 maxillary and mandibular molars with curvatures less than 45° (2691 root canals) over a 12-month period. All the treatments were performed in a single session. A total of 1104 WaveOne Gold instruments were used, including 38 small, 750 primary, 228 medium and 88 large instruments. Intracanal procedures were performed according to the manufacturer's recommendations, and each instrument was used in a single clinical case. The instruments were examined after their removal from the canal, under an operating microscope at 8× magnification. RESULTS: No fractures were observed in any of the 1104 instruments used. CONCLUSIONS: No fractures of WaveOne Gold reciprocating instruments occurred during root canal preparations performed in maxillary and mandibular molars with curvatures less than 45° when used strictly according to the manufacturer's recommendations and applied in a single clinical case.
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Oro , Preparación del Conducto Radicular , Cavidad Pulpar , Diseño de Equipo , Incidencia , Diente Molar , Estudios ProspectivosRESUMEN
AIM: To compare the shaping ability of four instrumentation systems in curved molar root canals, using computerized microtomography (micro-CT). METHODOLOGY: Forty mesial roots of mandibular molars were submitted first to radiographic examination to determine their curvature and then to a micro-CT scan to analyse other initial morphological characteristics. The specimens were distributed into four experimental groups, according to the endodontic instrumentation system used (n = 10): Group R, Reciproc; Group PTN, ProTaper Next; Group WOG, WaveOne Gold; Group PDL, ProDesign Logic. After root canal instrumentation, the specimens were submitted to a second micro-CT scan, and the pre- and postoperative data were examined to evaluate the following parameters: volume of dentine removed (DR), increase in root canal volume (VI), untouched root canal surface area (UA), volume of accumulated hard tissue debris (AD) and structure model index (SMI). The data observed for these parameters after instrumentation were analysed using generalized linear models. R software was used for the analyses, and the level of significance adopted was 5%. RESULTS: There were no significant differences among the instrumentation systems regarding the DR, VI, UA and AD parameters (P > 0.05). PTN and WOG systems were associated with greater increases in SMI than the PDL system (P < 0.05). CONCLUSIONS: The four systems evaluated were similar regarding the parameters analysed, with the exception of the SMI, with the rate of variation of this parameter being greater after using the PTN and WOG systems than after using the PDL system. These results indicate that the four systems perform similarly in terms of their shaping ability, but that the PTN and WOG systems produced more rounded preparations than the PDL system.
Asunto(s)
Cavidad Pulpar , Preparación del Conducto Radicular , Instrumentos Dentales , Diente Molar , Microtomografía por Rayos XRESUMEN
AIM: To compare the efficacy of reciprocating and rotary techniques with that of hand files for removing gutta-percha and sealer from root canals. METHODOLOGY: The root canals of fifty-four human extracted maxillary central incisors were cleaned and shaped using a crown-down technique to a size 40 and filled with gutta-percha and a zinc oxide-eugenol-based sealer using a lateral compaction technique. Teeth were divided into three groups according to the technique used for removing the root filling material: group I - Gates-Glidden burs and stainless steel hand files up to size 50; group II - rotary technique with NiTi Mtwo R files and additional Mtwo files to size 50, 0.04 taper; group III - reciprocating technique with the Reciproc instrument R50, size 50, 0.05 taper. Chloroform was used as a solvent in all groups. Teeth were then split longitudinally and photographed under 8× magnification. The images were transferred to a computer, and the total canal space and remaining filling material were quantified. The ratio of remaining filling material to root canal periphery was computed with the aid of Image Tool 3.0 software. The mean percentages of remaining filling material and time required to remove it were compared using the Kruskal-Wallis and Mann-Whitney tests (P < 0.05). RESULTS: The mean percentage of remaining filling material was significantly higher (P < 0.05) in group II, with Mtwo rotary files (12.17%), than in group I, with the hand file technique (7.19%), and group III, with Reciproc instruments (4.57%), which were statistically similar (P > 0.05). The time required to remove filling material was significantly shorter (P < 0.05) in group III (194 s), followed by group II (365 s) and group I (725 s) (P < 0.05). CONCLUSION: Remaining endodontic filling material was observed on the canal walls of all teeth regardless of the technique used. Hand files combined with Gates-Glidden burs (group I) and the reciprocating technique (group III) removed more filling material from the canal walls than the Mtwo R files. The reciprocating technique was the most rapid method for removing gutta-percha and sealer, followed by the rotary technique and the hand file technique.
Asunto(s)
Gutapercha/aislamiento & purificación , Materiales de Obturación del Conducto Radicular/aislamiento & purificación , HumanosRESUMEN
AIMS: To evaluate whether white mineral trioxide aggregate (MTA) or white Portland cement with 15% bismuth oxide were able to induce genetic damage and cellular death ex vivo. METHODOLOGY: Aliquots of 1 × 10(4) murine fibroblasts were incubated at 37 °C for 3 h with MTA (white) or white Portland cement with 15% bismuth oxide, at final concentrations ranging from 10 to 1000 µg mL(-1) individually. Data of three independent repeats from the comet assay and the trypan blue exclusion test were assessed by the one-way anova followed by Tukey's test. RESULTS: Mineral trioxide aggregate or Portland cement containing bismuth oxide did not produce genotoxic effects with respect to the single-cell gel (comet) assay data for all concentrations evaluated. Furthermore, no cytotoxicity was observed for MTA or Portland cement. CONCLUSION: White MTA or white Portland cement containing 15% bismuth oxide were not genotoxic and cytotoxic.
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Células 3T3-L1/efectos de los fármacos , Compuestos de Aluminio/toxicidad , Compuestos de Calcio/toxicidad , Cementos Dentales/toxicidad , Mutágenos/toxicidad , Óxidos/toxicidad , Materiales de Obturación del Conducto Radicular/toxicidad , Silicatos/toxicidad , Animales , Bismuto/toxicidad , Técnicas de Cultivo de Célula , Muerte Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Colorantes , Ensayo Cometa , Daño del ADN , Combinación de Medicamentos , Ensayo de Materiales , Ratones , Temperatura , Factores de Tiempo , Azul de TripanoRESUMEN
AIM: To report the endodontic treatment of an immature maxillary central incisor with dens invaginatus. SUMMARY: Dens invaginatus is a rare malformation of teeth, probably resulting from an infolding of the dental papilla during tooth development. The present case describes the complex endodontic treatment of a type III dens invaginatus in an immature maxillary central incisor with a necrotic pulp and abscess formation. The initial treatment goal was to achieve apexification of the pseudocanal root and conservative root canal treatment in the main canal. Following 1-year of treatment with calcium hydroxide dressings, radiography revealed a healing response, but no sign of a hard tissue barrier at the apex. Periapical surgery with the placement of a zinc oxide cement (IRM) root-end filling was considered successful at the 4-year follow-up. KEY LEARNING POINTS: The complexity of the canal system and open apex in dens invaginatus present a challenge to endodontic treatment. Correct diagnosis and treatment planning are fundamental to treatment of dens invaginatus. Periapical surgery is indicated in cases of unsuccessful apexification in immature teeth with dens invaginatus and nonvital pulp.
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Dens in Dente/complicaciones , Necrosis de la Pulpa Dental/terapia , Incisivo/patología , Tratamiento del Conducto Radicular/métodos , Apicectomía , Hidróxido de Calcio/uso terapéutico , Niño , Cavidad Pulpar/patología , Estudios de Seguimiento , Humanos , Masculino , Metilmetacrilatos/uso terapéutico , Absceso Periapical/terapia , Obturación Retrógrada/métodos , Materiales de Obturación del Conducto Radicular/uso terapéutico , Ápice del Diente/patología , Cemento de Óxido de Zinc-Eugenol/uso terapéuticoRESUMEN
Mechanical ventilation with high tidal volumes (V(T)) has been shown to induce lung injury. We examined the hypothesis that this procedure induces lung injury with inflammatory features. Anesthetized male Wistar rats were randomized into three groups: group 1 (N = 12): V(T) = 7 ml/kg, respiratory rate (RR) = 50 breaths/min; group 2 (N = 10): V(T) = 21 ml/kg, RR = 16 breaths/min; group 3 (N = 11): V(T) = 42 ml/kg, RR = 8 breaths/min. The animals were ventilated with fraction of inspired oxygen of 1 and positive end-expiratory pressure of 2 cmH2O. After 4 h of ventilation, group 3, compared to groups 1 and 2, had lower PaO2 [280 (range 73-458) vs 517 (range 307-596), and 547 mmHg (range 330-662), respectively, P<0.05], higher wet lung weight [3.62 +/- 0.91 vs 1.69 +/- 0.48 and 1.44 +/- 0.20 g, respectively, P<0.05], and higher wet lung weight/dry lung weight ratio [18.14 (range 11.55-26.31) vs 7.80 (range 4.79-12.18), and 6.34 (range 5.92-7.04), respectively, P<0.05]. Total cell and neutrophil counts were higher in group 3 compared to groups 1 and 2 (P<0.05), as were baseline TNF-alpha concentrations [134 (range <10-386) vs 16 (range <10-24), and 17 pg/ml (range <10-23), respectively, P<0.05]. Serum TNF-alpha concentrations reached a higher level in group 3, but without statistical significance. These results suggest that mechanical ventilation with high V T induces lung injury with inflammatory characteristics. This ventilatory strategy can affect the release of TNF-alpha in the lungs and can reach the systemic circulation, a finding that may have relevance for the development of a systemic inflammatory response.
Asunto(s)
Neumonía/etiología , Respiración Artificial/efectos adversos , Animales , Análisis de los Gases de la Sangre/métodos , Concentración de Iones de Hidrógeno , Pulmón/fisiopatología , Mediciones del Volumen Pulmonar , Masculino , Neumonía/fisiopatología , Ratas , Ratas Wistar , Volumen de Ventilación Pulmonar , Factores de Tiempo , Factor de Necrosis Tumoral alfa/análisisRESUMEN
Mechanical ventilation with high tidal volumes (V T) has been shown to induce lung injury. We examined the hypothesis that this procedure induces lung injury with inflammatory features. Anesthetized male Wistar rats were randomized into three groups: group 1 (N = 12): V T = 7 ml/kg, respiratory rate (RR) = 50 breaths/min; group 2 (N = 10): V T = 21 ml/kg, RR = 16 breaths/min; group 3 (N = 11): V T = 42 ml/kg, RR = 8 breaths/min. The animals were ventilated with fraction of inspired oxygen of 1 and positive end-expiratory pressure of 2 cmH2O. After 4 h of ventilation, group 3, compared to groups 1 and 2, had lower PaO2 [280 (range 73-458) vs 517 (range 307-596), and 547 mmHg (range 330-662), respectively, P<0.05], higher wet lung weight [3.62 ± 0.91 vs 1.69 ± 0.48 and 1.44 ± 0.20 g, respectively, P<0.05], and higher wet lung weight/dry lung weight ratio [18.14 (range 11.55-26.31) vs 7.80 (range 4.79-12.18), and 6.34 (range 5.92-7.04), respectively, P<0.05]. Total cell and neutrophil counts were higher in group 3 compared to groups 1 and 2 (P<0.05), as were baseline TNF-alpha concentrations [134 (range <10-386) vs 16 (range <10-24), and 17 pg/ml (range <10-23), respectively, P<0.05]. Serum TNF-alpha concentrations reached a higher level in group 3, but without statistical significance. These results suggest that mechanical ventilation with high V T induces lung injury with inflammatory characteristics. This ventilatory strategy can affect the release of TNF-alpha in the lungs and can reach the systemic circulation, a finding that may have relevance for the development of a systemic inflammatory response
Asunto(s)
Animales , Masculino , Ratas , Pulmón , Respiración Artificial , Análisis de los Gases de la Sangre , Recuento de Células , Concentración de Iones de Hidrógeno , Inflamación , Mediciones del Volumen Pulmonar , Neutrófilos , Ratas Wistar , Volumen de Ventilación Pulmonar , Factores de Tiempo , Factor de Necrosis Tumoral alfaRESUMEN
PURPOSE: This article describes a clinically-diagnosed case of relapsing polychondritis (RP), attended at the Hospital São Paulo, and presents a literature review of the subject. SOURCE OF RESEARCH: The literature review was made via Medline (1990-96). Lilacs (1980-96), textbooks of rheumatology, and some articles about the history of the disease. In Medline, 113 articles from 1990 to 1996 were found, and there were 23 articles from 1980 to 1996 in Lilacs. RESEARCH PROCEDURE: We reviewed the articles available at BIREME (Biblioteca Regional de Medicina) with the primary focus being on the disease in question. SUMMARY: RP is a rare disease of unknown etiology described initially by Jackson-Wartenhorst in 1923 and characterized by a recurrent and acute inflammatory process that causes the collapse of the cartilaginous structures and their subsequent replacement by fibrous connective tissue. The cartilage most commonly attacked is that of the auricle of the ear and nasal septum, while the cartilage of the trachea, larynx, epiglottis, ribs, and articulations may also be involved. Ocular inflammations and systemic reactions with fever are also described. In 1976, McAdam presented a complete prospective study of 23 patients, reviewed the 136 cases described up until that time, and then proposed diagnostic criteria which were later expanded by Damiani and Levine. Currently, more than 550 cases have been described. CONCLUSION: Although a rare disease, better knowledge of it is needed, as RP may be lethal with tracheal collapse and obstruction of respiratory pathways, making precise diagnosis and adequate therapeutic intervention necessary.
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Policondritis Recurrente/diagnóstico , Adulto , Humanos , Masculino , Policondritis Recurrente/complicacionesRESUMEN
A 42 year-old woman with terminal chronic lung disease underwent to left lung transplantation. Extracorporeal membrane oxigenation (ECMO) was required because dysfunction of transplanted organ occurred and was non-responsive to conventional therapy. The time of assistance was 47 hours and after this, the dysfunction of the transplanted lung reversed and the patient was weaned from the oxigenator. During hospital stay, she developed sepsis and died. In conclusion, ECMO was decisive to the treatment of pulmonary dysfunction, allowing time to the resolution of lung lesion.