ABSTRACT
Abstract The aim of this study was to evaluate root canal preparation with nickel titanium rotary instruments and complementary preparation with ultrasonic tip in curved canals of mandibular molars with isthmus. Twenty-eight mesial roots of mandibular molars with curvature between 20° and 40° and presence of isthmus throughout the entire extension of the root canals were prepared using ProDesign Logic CM (PDL) up to size 40.05, or HyFlex EDM (HFEDM) up to size 40.04. Complementary preparation was performed in the isthmus region using the ultrasonic insert E18D (Helse, Istmo Diamantada). The root canals were scanned using micro-CT (SkyScan 1176) at 9 µm voxel size before and after each preparation step. Transportation, percentage of increase in volume, debris and uninstrumented surface (UNS) were evaluated. Mann Whitney, Wilcoxon, paired and non-paired t-tests were used for statistical analysis (α = 0.05). The canals prepared with PDL and HFEDM obtained similar results for all the variables assessed before using E18D (p > 0.05). E18D significantly decreased the percentage of debris and UNS values in both Groups (p < 0.05). The complementary preparations with E18D caused a smaller quantity of debris in the isthmus of the canals previously prepared with PDL in comparison with HFEDM (p < 0.05). PDL and HFEDM provided similar root canal preparation. PDL promoted a smaller quantity of Debris in the isthmus than HFEDM after using E18D. E18D significantly improved cleaning, and reduced Debris and UNS.
ABSTRACT
Abstract Objective The aim of this study was to evaluate the root canal preparation and apical enlargement of molar root canals with rotary or reciprocating heat-treated nickel-titanium (NiTi) instruments, by using micro-computed tomography (micro-CT). Methodology Mesial root canals (n=48) of mandibular molars, with a curvature between 20° and 40°, were prepared with ProDesign Logic (PDL) 25.01 and 25.06 in rotary motion, or ProDesign R (PDR) 25.06 in reciprocating motion (PDR). Apical enlargement was performed with PDL35.01 and PDL35.05 or PDR35.05. Scanning with 9 µm resolution was performed before and after preparation, and, after apical enlargement, by using micro-CT. The percentage of volume increase, debris and untouched root canal surface, transportation, centralization and preparation time were analyzed. ANOVA and Tukey or Kruskall-Wallis and Dunn statistical tests were conducted (α=.05). Results PDL promoted a higher apical percentage of volume increase, and lower percentage of debris and untouched root canal surface than PDR 25.06 preparation in entire canal and in all thirds (P<.05). Apical enlargement with PDL 35.05 and PDR 35.05 produced a higher percentage of volume increase in the apical region in relation to the initial preparation (P<.05). PDR 35.05 and PDL 35.05 showed similar results in relation to percentage of debris and untouched root canal surface in entire canal and in all thirds (P>.05). Centralization and transportation showed no difference (P>.05). PDR required less time to perform preparation and apical enlargement (P<.05). Conclusions The apical enlargement 35.05 with CM heat-treatment instruments using reciprocating and rotary motion reduced the percentage of debris and untouched root canal surface, without causing deviations or procedural errors. The protocol of greater apical enlargement favors the cleaning of the root canals in both kinematics. Preparation by the reciprocating system was faster than by the rotary system.
Subject(s)
Humans , Titanium , Root Canal Preparation/instrumentation , Dental Instruments , Dental Pulp Cavity/diagnostic imaging , Nickel , Reference Values , Surface Properties , Materials Testing , Reproducibility of Results , Analysis of Variance , Statistics, Nonparametric , Dental Pulp Cavity/anatomy & histology , Equipment Design , X-Ray Microtomography , Hot TemperatureABSTRACT
PURPOSE: To revise and systematize scientific knowledge of the experimental model for cutaneous burns in rats. METHODS: A bibliographical review from 2008 up to January 2011 in PubMed, EMBASE and LILACS was undertaken. Were used the keywords: animal models, burns and rats. 221 studies were identified, and 116 were selected. RESULTS: It was found that: 54/86 (62.7%) had third degree burns; 55/73 (75.3%) studied the back; 45/78 (57.6%) used heated water and 27/78 (35.9%) incandescent instruments; 39/78 (50%) studied systemic effects; 22/71 (31%) used ketamine associated with xylazine; 61/64 (95.3%) performed depilation with appropriate equipment; 36/72 (50%) used microscopy; more than 50% did not describe analgesia or antibiotics during the postoperative period; in 42/116 (36.2%) postoperative fluid therapy was performed; and the time interval after the burn, up to the beginning of the results analysis varied from 7s up to four weeks. Legislation issues on burn experiments are discussed. CONCLUSION: The hot water was the main method to induce burns those of third degree on the back, with anesthesia using ketamine and xylazine, after depilation. These were evaluated microscopically, without using analgesia or an antibiotic during the postoperative period. The studies were not very reproducible.
OBJETIVO: Revisar e sistematizar o conhecimento científico do modelo experimental em queimadura da pele em ratos. MÉTODOS: Revisão da literatura foi realizada de 2008 a Janeiro de 2011 na PubMed, EMBASE e LILACS. Os descritores usados foram: modelo animal, queimadura e ratos. 221 estudos foram identificados e 116 foram selecionados. RESULTADOS: Foi encontrado que: 54/86 (62,7%) tinham queimadura de terceiro grau; 55/73 (75,3%) estudaram o dorso; 45/78 (57.6%) usaram líquido aquecido e 27/78 (35,9%) usaram instrumento incandescente; 39/78 (50%) estudaram efeitos sistêmicos; 22/71 (31%) usaram ketamina associada a xilazina; 61/64 (95,3%) realizaram depilação com equipamento apropriado; 36/72 (50%) usaram microscopia; mais de 50% não descreveram uso de analgésicos ou antibióticos durante o período pós-operatório; em 42/116 (36,2%) foi realizada reposição hídrica pós-operatória; e o intervalo de tempo após a queimadura e a análise variou de 7s a quatro semanas. Aspectos legais sobre experimentos em queimaduras foram discutidos. CONCLUSÃO: Líquido aquecido foi o principal método para induzir queimadura de terceiro grau no dorso do animal, com anestesia usando quetamina e xilazina, após depilação, avaliados por microscopia, sem uso de analgesia ou antibióticos. Os estudos não são reprodutíveis.
Subject(s)
Animals , Rats , Burns/pathology , Disease Models, Animal , Skin/pathology , Burns/physiopathology , Burns/therapy , Postoperative Period , Research DesignABSTRACT
Abordou-se a experiência do Servico de Cirurgia Plástica do Centro de Referência da Mulher e Hospital das Clínicas, na reparaçäo de areas cruentas em torax, após mastectomia radical por cancer mamário avançado (T3/T4). Analisaram-se 15 pacientes de junho /1994 a junho/1995, em que foram utilizados retalhos toraco-abdominal de rotaçäo pós-mastectomia. Todas as pacientes foram submetidas a radio/quimioterapia no pós-operatório, com seguimento de 6 meses em média. Ocorreram precocemente epidermolise (4 casos-26,6 por cento) e necrose distal do retalho (2 casos-13,3 por cento). Tardiamente observaram-se infecçäo local (1 caso), erisipela no membro superior ipsilateral (1 caso) e recidiva do tumor (2 casos). Estas intercorrencias nao interferiram na reintroduçäo do tratamento radio/quimioterápico