Differential bonds degradation of two resin-modified glass-ionomer cements in primary and permanent teeth
Introduction
There are substantial microstructural differences between permanent and deciduous dentin. Primary dentin has higher tubule density and diameter, resulting in a reduced area of intertubular dentin available for bonding.1 Chemically, primary dentin seems to be more reactive to the acidic conditioners,2, 3 which could be explained by the reduced degree of mineralization observed in primary dental hard tissues.4, 5 Due to these differences, most of the used protocols for dentin bonding are not as effective when applied to primary dentin as they are on permanent dentin.6, 7
Glass ionomer cements are usually selected for restoring primary teeth. The application of weak acids is required, in order to clean the tooth surface, remove the smear layer, and expose collagen fibrils, allowing glass-ionomer components to inter-diffuse and establish a micro-mechanical entanglement with dentin.8 Furthermore, chemical bonding may be attained, by ionic interaction of the carboxyl groups of the polyalkenoic acid with calcium ions of remnant hydroxyapatite that remain attached to the collagen fibril.9, 10, 11 Resin-modified glass-ionomer cements (RMGIC) are particularly promising for restorative indications.12 Chemical and/or hydrolytic degradation has been previously reported for resin–dentin bonded interfaces.13, 14, 15, 16, 17, 18 If RMGIC–dentin bonded interfaces are also prone to these degradation processes remains to be ascertained.19
The purpose of this study was to ascertain RMGICs–dentin bonds resistance to degradation. The null hypothesis to be tested is that there are no differences in bond strength resistance to degradation when using two different RMGICs on primary or on permanent dentin.
Section snippets
Specimens preparation
Twelve of each primary and permanent non-carious human molars were used in this study. The human molars were obtained after the institutional informed consent from all donators. The research was approved by the Research Ethics Commission. The teeth were cleaned with pumice/water slurry, rinsed and stored in distilled water in a refrigerator (4 °C) until use. The pulp chambers of crowns were sealed with composite resin and their cusps flattened with 220-grit abrasive paper. Occlusal Class I
Results
Mean bond strength values (MPa), obtained for primary and permanent dentin, are shown in Table 2. Bond strength was affected by dentin type (F = 71.00; p < 0.001) and NaOCl challenge (F = 33.21, p < 0.001). Interaction between RMGIC and NaOCl immersion was also significant (F = 11.95, p = 0.001).
At 24 h evaluation, dentin bond strengths were similar for both materials in permanent dentin. Bond strength values to primary dentin were higher than to permanent dentin when restored with Fuji II LC; while using
Discussion
In vitro dentin bond strength studies commonly use flat surfaces to test the bonding effectiveness of dental materials. Clinically, however, restorative materials are inserted into cavities. Two major considerations should be taken into account when using cavities instead of flat surfaces: (1) tensions are created at the material/dentin interfaces due to high polymerization contraction stress; such pre-stressed interfaces may be more susceptible to failure and degradation20, 21; and (2) the
Conclusions
Vitremer–dentin bonds are prone to degradation. Restoring primary dentin with Fuji II LC is preferred due to the particular tolerance to major water presence of this substrate. Chemical degradation of Fuji II LC–dentin bonds did not occur.
Acknowledgments
This investigation was supported by Grants CICYT/FEDER #MAT 2008-02347\MAT, JA P07-CTS-2568, JA P08-CTS-3944.
References (37)
- et al.
Micro-mechanical characterization of the properties of primary tooth dentine
Journal of Dentistry
(2003) - et al.
A comparison of microtensile bond strengths of several dentin bonding systems to primary and permanent dentin
Dental Materials
(2002) - et al.
Bonding efficacy of polyalkenoic acids to hydroxyapatite, enamel and dentin
Biomaterials
(2003) - et al.
The clinical performance of adhesives
Journal of Dentistry
(1998) - et al.
Degradation of resin–dentin bonds using NaOCl storage
Dental Materials
(2003) - et al.
Effect of cavity configuration and aging on the bonding effectiveness of six adhesives to dentin
Dental Materials
(2005) - et al.
Resistance to degradation of resin-modified glass-ionomer cements dentine bonds
Journal of Dentistry
(2009) - et al.
Durability of resin–dentin bonds: effects of direct/indirect exposure and storage media
Dental Materials
(2007) - et al.
Interaction of resin-modified glass-ionomer cements with moist dentin
Journal of Dentistry
(2004) - et al.
An FTIR study on the setting mechanism of resin-modified glass ionomer restoratives
Dental Materials
(1996)
Effect of region and dentin perfusion on bond strengths of resin-modified glass ionomer cements
Journal of Dentistry
Effect of surface treatments on the bond strength of glass ionomers to enamel
Dental Materials
Dental adhesion review: aging and stability of the bonded interface
Dental Materials
Resin-modified glass ionomer cements: bonding to enamel and dentin
Dental Materials
Failure of resin-modified glass-ionomers subjected to shear loading
Journal of Dentistry
Sorption and solubility of resin-based restorative dental materials
Journal of Dentistry
Microstructure of primary tooth dentin
Pediatric Dentistry
Dentin bonding: SEM comparison of the resin–dentin interface in primary and permanent teeth
Journal of Dental Research
Cited by (14)
Ethanol-wet bonding technique: Clinical versus laboratory findings
2015, Dental MaterialsCitation Excerpt :The longevity of the resin–dentin bonds produced with the ethanol-wet bonding technique has been observed only in laboratory studies [18,19,21] and further clinical studies are needed to validate or negate the in vitro findings. Although the present study was conducted in primary dentition, it is likely that the findings of the present study may also be applicable to permanent teeth, as it was already demonstrated that similar bond strength values could be obtained in both substrates [58–63]. The immediate benefits of the ethanol-bonding observed in the laboratory setting was not confirmed when the same protocol was performed in vivo.
Glass ionomer cements bond stability in caries-affected primary dentin
2014, International Journal of Adhesion and AdhesivesCitation Excerpt :This is in agreement with the results of a previous study that investigated the resistance to degradation of bonded interfaces produced by resin-modified GIC to caries-affected primary dentin, after pH- and load-cycling [24] and can explain the good retention rates of GIC restorations [29]. Although, Marquezan et al. [30] reported that interfaces produced by the resin-modified GIC are prone to degradation by 10% NaOCl, this chemical aging protocol is much more challenging than what occurs clinically. In this study, half the teeth of each group were stored in water, resembling better what happens in clinical settings.
Microhardness and chemical analysis of high-viscous glass-ionomer cement after 10 years of clinical service as ART restorations
2011, Journal of DentistryCitation Excerpt :Under high magnification, a zone of interaction between HVGIC and enamel could be observed along the interface in all the three samples with enamel presence (Fig. 3). This observation was similar to that reported by Ngo et al.26 and probably represents the ion-exchange or absorption layer.26–31 This ion-exchange layer is currently considered a significant feature in material classification.32
Towards a better understanding of the adhesion mechanism of resin-modified glass-ionomers by bonding to differently prepared dentin
2010, Journal of DentistryCitation Excerpt :Besides promoting a more intimate contact of the RMGI with the underlying dentin, the (partial) removal of surface smear by the polyalkenoic-acid conditioner may also increase dentin permeability and thus provide an important (additional) source of water to the direct benefit of the glass-ionomer acid-base setting reaction.25 This may promote GI maturation at the interface, rendering the bond of the RMGI to dentin more resistant to degradation over time.26 On the other hand, the use of Cavity Conditioner seems to be unimportant in absence of a smear layer.
Bond strength and nanoroughness assessment on human pretreated cementum surfaces
2010, Journal of DentistryDeep margin elevation with resin composite and resin-modified glass-ionomer on marginal sealing of CAD-CAM ceramic inlays: An in vitro study
2021, American Journal of Dentistry