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| Author(s): |
Fabio Roberto Dametto
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Piracicaba, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba |
| Defense date: | 2006-01-23 |
| Examining board members: |
Caio Cezar Randi Ferraz;
Welingtom Dinelli;
Alexandre Augusto Záia;
Francisco José de Souza Filho
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| Advisor: | Caio Cezar Randi Ferraz |
| Abstract | |
Most of the endodontic treatment failure cases are directly related to inadequate or absent restoration, which leads to coronal microleakage and root canal system recontamination. Hence, the aim of this research was to evaluate the influence of chemical substances auxiliary to the endodontic treatment on the adhesive system adherence to the deep pulp chamber dentin. Crowns of intact molars were transversally sectioned at 3 mm above the enamel-cement junction, so that the pulp chamber floor was exposed. The teeth were divided in 6 groups according to the auxiliary chemical substance used during the treatment, G1- physiologic solution, G2 17% EDTA, G3 5.25%NaOCl, G4- 5.25% NaOCl + 17% EDTA, G5- 2% Chlorhexidine gel and G6- 2% Chlorhexidine solution. All specimens of all groups were immersed in the respective chemical substance for 30 minutes. Afterwards, 4 mm of the pulp chamber were filled with adhesive system Single Bond® (3M, St. Paul, MN, USA) and the compound resin Z250® B2 shade (3M, St. Paul, MN, USA). Twenty teeth of each group were serially cut from mesial to distal into 1.0 mm slices. These slices were trimmed to an hourglass shape cuts with a cross-sectional area of 1.0 mm2 on the dentin of the pulp chamber floor or in the dentin-resin bond interface of the pulp chamber floor. Microtensile tests were used on the slices to evaluate cohesive resistance alterations on dentin and resistanc e of the dentin-resin bond. Ten teeth were submitted to coronary nanoleakage tests with silver nitrate. The results were statistically analyzed and showed that there are no statistical significant differences between groups regarding the cohesive resistance of the dentin. However, the dentinresin bond was lower (p<0.05) in the 17% EDTA group. All groups showed a typically mixed fracture pattern. The nanoleakage test did not show different patterns between groups evaluated on the SEM, as the infiltration occurred only on the pathways of tubules exposed to the marker. Moreover, there was no correlation between union resistance and nanoleakage. In conclusion, the auxiliary chemical substances tested, except the 17% EDTA, did not influence the dentin-resin bond mechanism on the pulp chamber floor (AU) | |