Effect of cariogenic challenge on the stability of dentin bonds

Abstract

ObjectiveThe oral environment is subject to biofilm accumulation and cariogenic challenge, and few studies exist on the effect of these factors on the bond strength of adhesive systems. The aim of this study was to test if the exposure of adhesive interfaces to cariogenic challenge under biofilm accumulation could promote higher degradation than the exposure to biofilm accumulation alone. Material And MethodsFive molars were ground until exposure of medium dentin and then restored (Single Bond 2 and Z250 3M ESPE). The tooth/resin sets were cut to obtain beam-shaped specimens, which were distributed according to the aging conditions (n=20): water for 24 h (control); biofilm under cariogenic challenge for 3, 5 or 10 days; biofilm without cariogenic challenge for 10 days; and water for 3 months. Microcosm biofilms were formed from human saliva and grown in a saliva analogue medium, supplemented or not with sucrose to promote cariogenic challenge. Specimens were tested for microtensile bond strength, and failure modes were classified using light microscopy. Bond strength data were analyzed using ANOVA and failure modes were analyzed using ANOVA on ranks (α=0.05). ResultsNo significant differences in bond strength were detected among the aging methods (P=0.248). The aging period was associated with an increase in the frequency of adhesive failures for the groups aged for 10 days or longer (P<0.001). ConclusionAging leads to a higher prevalence of interfacial adhesive failures, although this effect is not associated with cariogenic challenge or reduction in bond strengths.

Wall-lesion development in gaps: The role of the adhesive bonding material

“…This finding highlights the fragility of the adhesive interface and that the interaction between the adhesive monomer and the etched dentin is an instable structure when exposed to a cariogenic challenge. 18,19 However, in this study caries wall lesions only developed when there was a defect/gap on the adhesive interface. The presence of a perfect bonding prevented wall lesions, confirming earlier reports that the presence of a gap is a crucial factor in wall lesion development.…”

Influence of the Inoculum Source on the Cariogenicity of in vitro Microcosm Biofilms

“…Our results also show that depending on the research purpose of a microcosm study, that is, to test the effect of antibacterial material in a high cariogenic challenge environment [Zhang et al, 2012;Peralta et al, 2013;Borges et al, 2014], the choice of the type or source of inoculum is not a major factor that will influence the outcome of the study. In such cases a methodology for easier handling should be chosen.…”

“…In addition, the dental plaque samples were collected from specific sites, that is, from the surfaces of active white-spot caries lesions and from the correspondent locations in sound surfaces. The current methodology has been widely used in caries-related studies Peralta et al, 2013;Azevedo et al, 2014;Borges et al, 2014;Kuper et al, 2014;Maske et al, 2014]. Therefore the retrieved results contribute to the understanding of the influence of the inoculum source on the cariogenicity of biofilms grown under standardized conditions in a biofilm model.…”

Behavior of failed bonded interfaces under in vitro cariogenic challenge

“…Both ageing methods resulted in a similar decrease in the bond strength values. Water-storage is a popular artificial ageing and well-validated method to assess bond durability, showing decreasing in bond strength results long time [22]. The mechanical aging protocol with the Rub&Roll device has already been shown to decrease the bond strength values [12].…”