Aim Endocrown restorations are commonly used to rehabilitate endodontically treated posterior teeth and their use is well-founded in these cases. However, to date, there is little scientific evidence of their behavior in anterior teeth. The aim of this in vitro study was to evaluate the compressive strength of upper central incisors teeth, restored with glass-ceramic total crowns by the conventional anatomical core technique, and compare them to teeth restored with endocrowns with and without the presence of ferrule. Methods Thirty teeth were randomly distributed into three groups: GE2 - endocrown group with 2 mm ferrule, GE0 - endocrown group without a ferrule, and GC - conventional crown with intraradicular post group. Crowns were cemented and teeth submitted to the 45o compression test until the fracture happened. Fractured specimens were analyzed to determine the fracture pattern. Descriptive analysis of the variables was performed and one-way analysis of variance was utilized to analyze the data for significant differences at p < 0.05. Results The results of the control group (284.5 ± 201.05N) showed the highest fracture resistance value, followed by the 2mm group (274.54 ± 199.43N) and by the 0mm group (263.81 ± 80.05N). There was no statistically significant difference between all the groups (p = 0.964). Conclusions The absence of a cervical enamel necklace favored a debonding of the pieces and endodontically treated anterior teeth could be restored with endocrown, which could be considered a conservative and viable treatment option.

Avaliou-se a infiltração marginal apical em obturações endodônticas utilizando dois tipos de cimentos após a aplicação do laser Nd:YAG ou solução de EDTA nas paredes do canal radicular. Utilizou-se sessenta e dois dentes pré-molares inferiores humanos que tiveram seus canais radiculares instrumentados por técnica mecanizada. Em seguida, as superfícies externas radiculares foram impermeabilizadas, exceto o forame apical. As raízes foram, então, divididas em 4 grupos de 15, de acordo com o tipo de tratamento realizado nas paredes dos canais radiculares e o tipo de cimento utilizado para a obturação. Grupo I - aplicação do laser Nd:YAG e obturação com cimento AH Plus; Grupo II - aplicação do laser Nd:YAG e obturação com cimento Endofill; Grupo III - aplicação de EDTA por 5 minutos e obturação com cimento AH Plus; Grupo IV - aplicação de EDTA por 5 minutos e obturação com cimento Endofill. Dois dentes serviram como controles positivo e negativo. Em seguida, as raízes foram imersas em solução de azul-de-metileno a 2%, durante 48 horas. Após remoção da impermeabilização foi realizado o desgaste das raízes para leitura da magnitude das infiltrações, por meio de um microscópio óptico pela técnica da planimetria. Os resultados indicaram que o cimento AH Plus foi o que permitiu menor infiltração apical, assim como a aplicação do laser Nd:YAG, quando utilizado no tratamento das paredes dos canais radiculares, anteriormente à obturação.

Marginal apical leakage was evaluated in root canal filling performed with two sorts of cements after applying Nd:YAG laser or an EDTA solution in the root canal walls. Sixty-two human lower premolars had their canals instrumented through mechanical technique. Afterwards the external root surfaces were impermeabilized, except for the foramen. The roots were then divided into 4 groups of 15, according to the type of treatment performed on the root canal walls and the type of cement utilized in the filling. Group I - application of Nd:YAG laser and filling with AH Plus cement; Group II - application of Nd:YAG laser and filling with Endofill cement; Group III - application of EDTA for 5 minutes and filling with AH Plus cement; Group IV - application of EDTA for 5 minutes and filling with Endofill cement. Two teeth served as negative and positive controls. Afterwards, the roots were immersed in a 2%-methylene blue dye, for 48 hours. Wearing of the roots took place following the removal of impermeabilization for the reading of leakage magnitude, by means of a light microscope through planimetry technique The results indicated AH Plus cement as the one to allow the least apical leakage, as well as Nd:YAG laser application, when utilized in the treatment of root canal walls, prior to filling.