Full text
| |
| Author(s): |
Patrícia Almada Sacramento
Total Authors: 1
|
| Document type: | Doctoral Thesis |
| Press: | Piracicaba, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba |
| Defense date: | 2010-12-14 |
| Examining board members: |
Regina Maria Puppin Rontani;
José Carlos Pettorossi Imparato;
Roberta Caroline Bruschi Alonso;
Mário Alexandre Coelho Sinhoreti;
Luís Roberto Marcondes Martins
|
| Advisor: | Regina Maria Puppin Rontani |
| Abstract | |
The objective of this Thesis, presented in two chapters, was to evaluate the effect of chlorhexidine-CHX and the antibacterial monomer 12-metacriloxydodecylpiridinium-MDPB on the bond strength and bonding degradation of the resin/demineralized dentin interface over twelve months of storage time. Chapter 1: The objective of this in vitro study was to evaluate the effect of CHX and/or different adhesive systems, in the penetration of monomers in demineralized dentin, as well as on the formation and thickness of the hybrid layer using Confocal Laser Scanning Microscopy (CLSM). Three adhesive systems were used: Clearfil SE Bond- (Kuraray), Clearfil Protect Bond - PB (Kuraray) and Adper Single Bond 2 - SB (3M/ESPE), and an antibacterial agent: 2% chlorhexidine solution (FGM) used for cavity disinfectant. Thirty sound third molars were randomly distributed into 6 groups according the adhesive systems SE, PB and SB, with or without previous CHX application. The middle dentin was exposed and the artificial caries lesion was developed with a carboxymethylcellulose acid gel previously the bonding procedure. CLSM images were analysed by the Analysis of Variance and Tukey's post hoc tests (P<0.05). The CHX and the MDPB did not interfere with the penetration of the adhesive systems in demineralized dentin. All the groups presented a hybrid layer formation, with significantly thicker and lower homogeneity in the SB groups, regardless of the CHX application. It was concluded that the CHX and the different adhesive system did not affect the penetration of monomers in the demineralized dentin. Only the adhesive system affected the thickness and homogeneity of hybrid layer. Chapter 2: The objective of this in vitro study was to evaluate the influence of CHX, MDPB and storage time in regard to the bond strength and the bonding degradation of resin/demineralized dentin interface by microshear (µSBS) and nanoleakage evaluation.Two adhesive systems were used: Clearfil SE Bond- SE (Kuraray), Clearfil Protect Bond- PB (Kuraray). One hundred twenty sound third molars were randomly distributed into 12 groups according to the adhesive systems, SE and PB, with or without previous CHX application on the bonding surface, and storage time of 24h, 6 and 12 months. The middle dentin was exposed and a artificial caries lesion was developed artificially. After 24h of storage, the SE groups presented the lower µSBS values, but they did not have statistical significant differences after 6 and 12 months of storage. The failure mode and the nanoleakage were evaluated descripitivelly. The nanoleakage of the resin/dentin interface was verified in all the groups, having a greater silver deposit in the CHX groups. An increase in the silver deposit and decrease in the µSBS values were noticed in all the groups after 6 months of storage. The CHX and the MDPB were not able to inhibit the nanoleakage and a decrease in bond strength. It was concluded that the CHX did not affect the penetration of the adhesive systems in the demineralized dentin, affected the hybrid layer formation, but it did not affect the imediate values of the bond strength, which were modified with the storage time, as was the nanoleakage in bonding interface, after 6 and 12 months. (AU) | |