ABSTRACT
Abstract The aim of this study was to evaluate the effect of magnification during post space preparation on root cleanness and on fiber post bond strength. Methods: Thirty human central upper incisors with similar root canal in size and shape were selected, decoronated to 15 mm and endodontically filled. The teeth were assigned into 3 groups (n=10), according to the method of magnification during post space preparation inspection: Control, using naked eye; loupe, using a dental surgical 3x magnifying glass; surgical microscope, using a 6x surgical microscope. The roots were scanned by using micro-CT before and after post space preparation for residue remnants evaluation. Fiber posts were cemented using self-adhesive resin cement (Rely X U200, 3M-ESPE). Two 1-mm-thick slices from the cervical, medium and apical thirds were submitted to a push-out test (PBS). Failures modes were classified. PBS data were analyzed by using two-way ANOVA with repeated measurement and the Tukey test. The significance level was set at 5%. The method of visualization had no effect on PBS (p=0.556). The cervical region had higher values than apical region irrespective of the inspection method (p=0.012). Adhesive failure between the resin cement and dentin was the prevalent failure mode for all groups. Micro-CT analysis showed no difference on root cleanness into the root canal after post space preparation. The use of magnification devices as loupe and microscope while performing post space do not improve the PBS and did not affect sealer remain of decoronated anterior teeth.
Resumo Avaliar o efeito do método de visualização durante o preparo do espaço do pino sobre o remanescente de material obturador endodôntico e sobre a resistência adesiva do pino de fibra de vidro. Trinta incisivos centrais superiores humanos com canal radicular circular foram selecionados, foram desobstruídos a 15 mm e obturados. Os dentes foram divididos em 3 grupos (n=10), de acordo com o método de ampliação utilizado para inspeção do preparo: Controle, usando olho nu; lupa, usando uma lupa cirúrgica 3x cirúrgica; microscópio cirúrgico, usando um microscópio cirúrgico 6x. As raízes foram digitalizadas usando micro-CT antes e após a preparação do espaço para avaliação de resíduos remanescentes. Os pinos de fibra foram cimentados com cimento resinoso autoadesivo (RelyX U200, 3M-ESPE). Duas fatias de 1 mm de espessura dos terços cervical, médio e apical foram submetidas ao teste push-out (PBS). Os padrões de falhas foram classificados. Os dados de PBS foram analisados usando análise de variância em dois fatores com medição repetida e o teste de Tukey. O nível de significância foi estabelecido em 5%. Resultados: O método de visualização não teve efeito no PBS (p=0,556). A região cervical apresentou valores maiores que a região apical, independentemente do método de inspeção (p=0,012). A falha adesiva entre o cimento resinoso e a dentina foi o modo de falha prevalente para todos os grupos. A análise de micro-CT não mostrou diferença na limpeza da raiz no canal radicular após a preparação do espaço do pino. Conclusão: O uso de dispositivos de ampliação como lupas e microscópios durante a realização de preparo não melhora o PBS e não afetou a permanência do material obturador remanescente de dentes anteriores.
Subject(s)
Humans , Post and Core Technique , Dental Bonding , Materials Testing , Dentin-Bonding Agents , Resin Cements , Dental Pulp Cavity , DentinABSTRACT
Abstract: Endodontic treatment is a common dental procedure used for treating teeth which the pulp tissue has become irreversibly inflamed or necrotic as a result of the carious process or dental trauma. This procedure which involves mechanical and chemical preparation of root canal may affect several mechanical and physical properties of the tooth structure. The endodontic treatment can also influence the longevity of the rehabilitation of endodontically treated teeth and biomechanics during the oral function. For restoring endodontically treated teeth several factor and clinical decisions should be observed. The decision of the fiberglass post usage and the restorative materials are related to several factors such as the quantity and quality of remaining dental structure, presence of ferrule, post cementation length and final coronal restoration. In this review, the authors will address the effect of the endodontic treatment procedures on canal shape and mechanical properties of a tooth, and also discuss the parameters and the biomechanical principles of root canal treated teeth.