In vitro analysis of thermocompaction time and gutta-percha type on quality of main canal and lateral canals filling

The aim of this study was to evaluate the quality of filling in main and lateral root canals performed with the McSpadden technique, regarding the time spent on the procedure and the type of gutta-percha employed. Fifty simulated root canals, made with six lateral canals placed two apiece in the cervical, middle and apical thirds of the root, were divided into 5 groups. Group A: McSpadden technique with conventional gutta-percha, performed with sufficient time for canal filling; Group B: McSpadden technique with conventional gutta-percha, performed in twice the mean time used in Group A; Group C: McSpadden technique with TP gutta-percha, performed with sufficient time for canal filling; Group D: McSpadden technique with TP gutta-percha, performed in twice the mean time used in Group C; Group E: lateral condensation technique. Images of the filled root canals were taken using a stereomicroscope and analyzed using the Leica QWIN Pro software for filling material flow, gutta-percha filling extension and sealer flow. Data were analyzed by analysis of variance (ANOVA) and Tukey test (p < 0.05). The best values of penetration in lateral canals in the middle third occurred in the groups where TP gutta-percha was used. However, in the apical third, group B showed the best values. Although a longer time of compactor use allows greater penetration of the filling material into the lateral canals, the presence of voids resulted in bad quality radiographic images, suggesting porosity. The best quality of filling material was observed in Group A (McSpadden technique with conventional Gutta-Percha, performed with sufficient time for root canal filling)

Seal capability of interim post and core crown with temporary cements

The purpose of the present study was to evaluate the in vitro seal capability of interim post and core crown restorations. Eighty teeth were selected and divided into 8 groups. Four experimental groups received interim posts and core crowns. Half of each group was decoronated at the cementum-enamel junction, groups PCCH and PCZO. The other half was sectioned 2 mm coronal to the cementum-enamel junction, groups PCrZO and PCrCH. The interim post and core crowns were luted with Rely X Temp NE, groups PCrZO and PCZO; Hydro C was used for Groups PCrCH and PCCH. The control groups, PC and PCr, received uncoated post and core crowns; groups OTg and OT were left without interim post and core crowns and were totally open. Infiltration was accessed by dye exposure followed by demineralization of the teeth. The length of the infiltration was measured using digital images taken from the specimens. The images were inserted into the Image Tool 3.0 software. Kruskal-Wallis analysis of variance and Dunn's multiple comparison method were used to test for significant differences among test groups (P < .05). Groups PCrZO and PCrCH showed the least dye penetration, followed by groups PCZO and PCCH. Teeth restored with interim post and core crowns will be subject to leakage. Ethics Committee: 095/2008