O propósito deste estudo foi avaliar a influência de protocolos de secagem do canal na resistência de união (RU) e no selamento apical (SA) de obturações com AH Plus, Sealapex e MTA Fillapex. Cento e cinquenta e seis raízes de caninos superiores foram submetidas à biomecânica com sistema Reciproc (R50) e distribuídas de acordo com o protocolo de secagem (PS): GI- cones de papel; GII- álcool isopropílico 70% + aspiração com pontas NaviTips; GIII- etanol 95% + cones de papel; GIV- EndoVac + cone de papel. Cada grupo foi dividido em subgrupos conforme o cimento obturador: A- AH Plus; B- Sealapex; C- MTA Fillapex. Utilizou-se para todos os espécimes técnica de obturação do cone único. As raízes de cada subgrupo foram destinadas à avaliação do SA (n=8) e RU (n=5), por meio do método de filtração de fluidos (FF) e push-out (PO), respectivamente. Para o PO as raízes foram seccionadas e um slice de cada terço submetido ao teste e à análise do tipo de falha. Os dados foram submetidos aos testes Anova two-way e three-way e Tukey por meio dos software SPSS 15.0 e SigmaStat 3.5 (α=5%). Os resultados da FF mostraram diferença significante entre os cimentos MTA e Sealapex (p<0,05). O SA não sofreu influência dos protocolos. Na RU não houve diferença entre os terços do canal (p>0,05), mas houve entre os cimentos (p<0,05), protocolos (p<0,05) e na interação cimentos/protocolos (p<0,05). O AH Plus (1,39±0,60) apresentou os maiores valores de RU em relação ao Sealapex (0,83±0,33) e MTA (0,76±0,34). Espécimes secos com álcool isopropílico proporcionaram aos cimentos testados maior resistência de união que quando secos com etanol (p=0,005) e EndoVac (p=0,002). Canais secos com etanol não influenciaram os cimentos. O uso de cones de papel, EndoVac e álcool isopropílico e obturação com AH Plus apresentaram os maiores valores RU que os demais cimentos. Concluiu-se que a infiltração ocorrida com o AH Plus foi semelhante a dos demais cimentos. O AH Plus apresentou os maiores valores de RU. No terço cervical houve predominância de falhas coesivas e de mistas nos demais terços.

The purpose of this study was to evaluate the influence of drying protocols in the bond strength (BS) and in the apical sealing (AS) of teeth filled with AH Plus, Sealapex and MTA Fillapex. One hundred and fifty-six roots of maxillary canines were subjected to biomechanical preparation with Reciproc (R50) and hand out according to the drying protocol (DP): GI-paper points; GII-70% isopropyl alcohol + aspiration with NaviTip points; GIII-95% ethanol + paper points; GIV-EndoVac + paper points. Each group was divided into subgroups according the used sealer: A- AH Plus; B- Sealapex; C- Fillapex MTA. The single cone obturation technique was used for all the samples. The roots of each subgroup were intended for the evaluation of the AS (n = 8) and the BS (n = 5) by using the fluid filtration (FF) and the push-out (PO) methods, respectively. Regarding the PO, the roots were sectioned and a single slice from each third was subjected to testing and also analysed for the type of failure. Data was submitted to the Tukey, two-way and the three-way variance analysis (ANOVA) resorting the SPSS 15.0 and the SigmaStat 3.5 (α= 5%) software. The results of the FF revealed a statistical significant difference between the MTA and the Sealapex (p <0.05) sealers. The AS showed no influence of the protocols. When it comes to the BS there was no statistical significant difference between the canal thirds (p> 0.05), but there was between the sealers (p <0.05), the protocols (p <0.05) and in the interaction between the sealers and the protocols (p <0.05). AH Plus (1.39 ± 0.60) revealed the highest BS comparing with Sealapex (0.83 ± 0.33) and MTA (0.76 ± 0.34). The specimens in which the isopropyl alcohol was used, had the highest bond strength results for the sealers, comparing with ethanol (p = 0.005) and EndoVac (p = 0.002). In the canals that ethanol was used, no alteration of the sealer was noticed. The use of paper points, EndoVac and isopropyl alcohol and filling with AH Plus revealed the highest BS values comparing with the other sealers. It was concluded that the infiltration that occurred with AH Plus was similar with the other sealers. AH Plus showed the highest BS. In the cervical third there was preponderance of cohesive failures, and in the other thirds the mixed type of failure.