ABSTRACT
Objetivo: O objetivo deste estudo foi responder qual é a melhor técnica para remoção de pinos de fibra de vidro e pinos metálicos fundidos considerando tempo, preservação da estrutura dentária e custos. Métodos: Foi realizado um estudo in vitro, randomizado e cego. Sessenta dentes tratados endodonticamente foram randomizados em dois grupos de acordo com o tipo de pino. Uma segunda randomização foi realizada para cada tipo de técnica de remoção (ultrassom, broca ou combinada; n=10). One-way ANOVA foi usado para comparar o tempo de remoção do pino, teste t pareado comparou a quantidade de estrutura dentária removida e Kruskal Wallis seguido pelo teste post hoc de Mann-Whitney foram usados para análise de custo (P = 0,05). Resultados: Não houve diferença no tempo de remoção do pino considerando o tipo ou técnica do pino (P=0,630). A perda média de estrutura dentária na região cervical foi superior a 30% quando apenas uma ponta diamantada foi usada para remover pino de fibra de vidro (P<0,00001) e pino metálico fundido (P=0,008). Conclusão: De acordo com os resultados deste estudo, podemos concluir que a seleção da técnica de remoção dependerá da habilidade do operador, e sempre ocorrerá alguma perda de estrutura dentária, embora seja esperada uma perda maior quando apenas pontas diamantadas são usadas para este fim.(AU)
Objective: The aim of this study was to answer which is the best technique to removing glass fiber post and cast metal post considering time, preservation of tooth structure, and costs. Methods: An in vitro, randomized, blinded study was conducted. Sixty endodontically treated teeth were randomized into two groups according to post type. A second randomization was performed for each type of removal technique (ultrasound, drill, or combined; n=10). One-way ANOVA was used to compare the time to post removal, paired t-test compared the amount of tooth structure removed and Kruskal Wallis followed by post hoc Mann-Whitney test were used for cost analysis (P=0.05). Results: There was no difference in post removal time considering post type or technique (P=0.630). The average loss of tooth structure in the cervical region was greater than 30% when only a diamond bur was used to remove fiber glass post (P<0.00001) and cast metal post (P=0.008). Conclusion: According to the results of this study, we can conclude that the selection of the removal technique will depend on the skill of the operator, and some loss of tooth structure will always occur, although greater loss is expected when only diamond burs are used for this purpose.(AU)
Subject(s)
Humans , Post and Core Technique/economics , Device Removal/economics , Dental Pins/economics , Reference Values , Time Factors , Random Allocation , Analysis of Variance , Statistics, Nonparametric , Costs and Cost Analysis , Device Removal/methodsABSTRACT
Endodontic retreatment is a considered as a comprehensive field, divided into various categories such as coronal disassembly, removing obturation materials, locating previously missed canals, etc. This field of endodontics has its own technologies and techniques that are required to achieve clinical success. Because the field of non-surgical retreatment is comprehensive, this case report will limit its focus to the removal of the post. Removal of posts from endodontically treated teeth is a major obstacle in the retreatment of teeth having recurrent pathology, which often leads to the extraction of a tooth that might have been saved with endodontic retreatment. This case report shows the non-surgical endodontic retreatment of incompletely obturated maxillary central incisors by removal of metallic posts.
Subject(s)
Adolescent , Endodontics/instrumentation , Endodontics/methods , Humans , Incisor/therapy , Male , Metals , Post and Core Technique , Retreatment/methods , Root Canal Filling Materials , Tooth Root/therapyABSTRACT
OBJECTIVES: To evaluate the effect of different ultrasonic tip designs on intraradicular post removal. MATERIALS AND METHODS: The crowns of forty human canine teeth were removed, and after biomechanical preparation and filling, the roots were embedded in acrylic resin blocks. The post spaces were made, and root canal molding was performed with self-cured acrylic resin. After casting (Cu-Al), the posts were cemented with zinc phosphate cement. The specimens were randomly separated into 4 groups (n = 10), as follows: G1 - no ultrasonic vibration (control); G2 - ultrasonic vibration using an elongated cylindrical-shaped and active rounded tip; G3 - ultrasonic vibration with a flattened convex and linear active tip; G4 - ultrasonic vibration with active semicircular tapered tip. Ultrasonic vibration was applied for 15 seconds on each post surface and tensile test was performed in a Universal Testing Machine (Instron 4444 - 1 mm/min). RESULTS: G4 presented the highest mean values, however, with no statistically significant difference in comparison to G3 (P > 0.05). G2 presented the lowest mean values with statistically significant difference to G3 and G4 (P < 0.05). CONCLUSIONS: Ultrasonic vibration with elongated cylindrical-shaped and active rounded tip was most effective in reducing force required for intraradicular post removal.
Subject(s)
Humans , Crowns , Cuspid , Dental Pulp Cavity , Fungi , Ultrasonics , Vibration , Zinc Phosphate CementABSTRACT
This in vitro study compared different ultrasonic vibration modes for intraradicular cast post removal. The crowns of 24 maxillary canines were removed, the roots were embedded in acrylic resin blocks, and the canals were treated endodontically. The post holes were prepared and root canal impressions were taken with self-cured resin acrylic. After casting, the posts were cemented with zinc phosphate cement. The samples were randomly distributed into 3 groups (n=8): G1: no ultrasonic vibration (control); G2: tip of the ultrasonic device positioned perpendicularly to core surface and close to the incisal edge; and G3: tip of the ultrasonic device positioned perpendicularly to core surface at cervical region, close to the line of cementation. An Enac OE-5 ultrasound unit with an ST-09 tip was used. All samples were submitted to the tensile test using an universal testing machine at a crosshead speed of 1 mm/min. Data were subjected to one-way ANOVA and Tukey's post-hoc tests (α=0.05). Mean values of the load to dislodge the posts (MPa) were: G1 = 4.6 (± 1.4) A; G2 = 2.8 (± 0.9) B, and G3= 0.9 (± 0.3) C. Therefore, the ultrasonic vibration applied with the tip of device close to the core's cervical area showed higher ability to reduce the retention of cast post to root canal.
Este estudo in vitro comparou diferentes modos de vibração ultra-sônica na remoção de pinos intra-radiculares fundidos. As coroas de 24 caninos superiores foram removidas, as raízes foram incluídas em blocos de resina acrílica e tratadas endodonticamente. Os espaços para os pinos intra-radiculares foram preparados e depois moldados com resina acrílica autopolimerizável. Após a fundição, os pinos intra-radiculares foram cimentados com cimento de fosfato de zinco. As amostras foram distribuídas aleatoriamente em três grupos (n=8): G1: sem vibração ultra-sônica (controle), G2: ponta do aparelho ultra-sônico posicionada perpendicularmente à superfície do núcleo e perto da borda incisal e G3: ponta do aparelho ultra-sônico posicionada perpendicularmente à superfície do núcleo na região cervical, perto da linha de cimentação. Uma unidade de ultra-som Enac OE-5 com uma ponta ST-09 foi usada. Todas as amostras foram submetidas ao teste de tração utilizando máquina universal de ensaios a uma velocidade de 1 mm/min. Os dados foram submetidos aos testes ANOVA e Tukey post-hoc (α = 0,05). Os valores médios de carga para deslocar os pinos (MPa) foram: G1 = 4,6 (± 1,4) A; G2 = 2,8 (± 0,9), B e G3 = 0,9 (± 0,3) C. Portanto, a vibração ultra-sônica aplicada com a ponta do dispositivo perto da zona cervical do núcleo apresentou maior capacidade de reduzir a retenção de pinos metálicos fundidos no canal radicular.