In vitro caries inhibition at the enamel margins of glass ionomer restoratives developed for the ART approach
Introduction
Recently, several hand-mixed conventional glass ionomer cements (GICs) have been manufactured specifically for the atraumatic restorative treatment (ART) technique or approach [1]. Minimal cavity preparations using hand instruments and newer more-viscous aesthetic GICs are part of the ART approach, which has been developed to provide urgently needed treatment for dental caries where conventional methods of dental care are either not available or are too costly. However, the newer GICs also have a role in dental care for patients in industrialized countries.
Fluoride was initially incorporated into early GIC glasses to modify the setting reaction [2], but it was subsequently demonstrated by many workers that the leaching of fluoride ions from the cements was associated with an in vitro reduction in enamel demineralization. Reports have shown that the newer more-viscous GICs release substantially less cumulative fluoride ions than less-viscous aesthetic restorative GICs and resin-modified GICs [3], [4], [5], [6], [7], [8], [9], [10], [11]. The effect of the lower fluoride ion release on the ability of the more-viscous GICs to inhibit dental caries in adjacent tooth tissues is not known, and several in vitro studies have shown variations among different restorative materials in their inhibition of caries-like lesions in enamel. Generally, non-fluoride ion releasing restorative materials have had no or minimal inhibition and, although the degree of inhibition associated with fluoride ion releasing materials may not necessarily be directly related to the levels of release, any significant effect is usually restricted to the immediate vicinity of the restoration margins, and the findings can be confounded by the direction of the enamel prisms [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23].
Part of the requirements of a restorative material used with the ART approach is its ability to remineralize carious tissue remaining after hand excavation [24] and to prevent secondary caries [25], [26]. This in vitro study examines the ability of two GIC restoratives manufactured for use with the ART approach to inhibit the demineralizing effects on enamel from an artificial caries challenge.
Section snippets
Artificial caries challenge
Human permanent premolar teeth, recently extracted as part of orthodontic treatments, were stored in 0.1% thymol phosphate buffered saline solution. Soft tissues and deposits were removed with hand scaling and with pumice slurry in a rotating brush. The cleaned buccal and lingual enamel surfaces were examined at 12× magnification with a stereoscopic SMZ microscope (Nikon, Tokyo, Japan) to choose sites without caries, cracks or intrinsic staining, particularly from fluorosis and tetracyclines.
Surface loss of restorative material
The overall mean depth of surface loss of material adjacent to the cavity walls was 27±40(SD) μm, as shown in Table 2. This overall loss was fairly similar at the cervical and coronal margins of the preparations. However, as shown in Table 3, the erosion for the hand-mixed Fuji IX and the encapsulated Fuji IX GP was significantly greater than that for the encapsulated Ketac-Molar and Compoglass p<0.0001.
Inhibition of enamel demineralization adjacent to cavity margins
All sites showed some birefringence patterns in the
Surface loss of restorative material
All restorative materials showed some surface loss due to erosion from the demineralizing solution. However, the effects were significantly less for Ketac-Molar and Compoglass, Table 3. Other in vitro studies have also shown the deleterious effects of moisture and acidic solutions on GIC solubility [4], [7], [27]. However, surface hardening of Fuji IX GP has been shown to occur when the cement was stored in human saliva [28], which may reduce its surface erosion in vivo. Resistance by GICs to
Conclusions
Within the limits of this in vitro study it was found that:
- 1.
The two viscous aesthetic conventional GICs marketed for use with the ART approach, and the compomer, conferred some protection to the adjacent enamel against an artificial caries challenge.
- 2.
The GICs showed more instances (20.5–25.0%) of inhibition of demineralization than did the compomer (13.0%) immediately adjacent to the restorations. However, there was considerable variation among the materials in the widths of the inhibition zones
Acknowledgements
Dr M.S. Gale is gratefully acknowledged for writing and testing the image analysis software. Financial assistance from a Hong Kong RGC award (10201736323) and a University of Hong Kong award (10201736324) are also gratefully acknowledged, as was the supply of commercial materials from the manufacturers, and the assistance of Dr W.T.C. Lam, Prince Philip Dental Hospital.
References (34)
Composition and characteristics of glass ionomer cements
J Am Dent Assoc
(1990)- et al.
Artificially formed caries-like lesions around restorative materials
J Am Dent Assoc
(1989) - et al.
Caries inhibition by a resin-modified and a conventional glass ionomer cement in vitro
J Dent
(1996) - et al.
In vitro caries inhibition by polyacid-modified composite resins (‘compomers’)
J Dent
(1998) - et al.
In vitro secondary caries inhibition around fluoride releasing materials
J Dent
(1998) - et al.
The orientation and direction of rods in dental enamel
J Prosthet Dent
(1991) Relationship between human enamel structure and the formation of caries-like lesions in vitro
Arch Oral Biol
(1984)- et al.
Manual for the atraumatic restorative treatment approach to control dental caries
(1997) - et al.
Fluoride release from Fuji IX and other fast-setting GICs
J Dent Res
(1995) - Lam WTC, Smales RJ, Yip HK. In vitro fluoride release and weight loss from ionomer cements. In: First European Union...
The assessment of the fluoride uptake and release from resin-modified glass-ionomer restorative materials and fissure sealants
J Dent Res
Release of fluoride from Fuji II LC, Fuji IX and Compoglass, immersed in acetate buffer solutions
J Dent Res
Fluoride release and weight loss from ART technique GICs
J Dent Res
ART technique: comparison between three glass ionomeric cements
J Dent Res
Fuji IX glass ionomers: fluoride release
J Dent Res
The release of fluoride from five conventional glass-ionomer cements
J Dent Res
Comparison of fluoride release from five conventional glass ionomer cements
J Dent Res
Cited by (45)
Effect of conditioning and 1 year aging on the bond strength and interfacial morphology of glass-ionomer cement bonded to dentin
2021, Dental MaterialsCitation Excerpt :GIC is one example of a dental bioactive material. It has both remineralization and anti-microbial ability [10–13] and has been used for dental restoration and the Atraumatic Restorative Treatment (ART) technique reliably for a long time [14,15]. Although resin composite is the major dental restorative material used nowadays, GICs are often used in clinical situations because of their technique simplicity, cost effectiveness and relative tolerance in the moist oral environment.
Mineral loss on adjacent enamel glass ionomer cements restorations after cariogenic and erosive challenges
2011, Archives of Oral BiologyCitation Excerpt :These cements are indicated specially for performing Atraumatic Restorative Treatment (ART) and favourable results with respect to their physical properties have been documented.6 Nevertheless, reports have suggested that the newer more-viscous GICs and resin-modified GICs release considerably less cumulative fluoride ions than less-viscous aesthetic restorative.7 Although remineralization ability to surrounding enamel has been confirmed by GIC under an acidic attack after cariogenic challenge,8 there is little evidence about the influence of their properties with respect to an erosive challenge.9,10
Fluoride release and absorption at different pH from glass-ionomer cements
2006, Dental MaterialsChanges in Gloss Alteration, Surface Roughness, and Color of Direct Dental Restorative Materials after Professional Dental Prophylaxis
2024, Journal of Functional BiomaterialsSealing of carious lesions in deciduous molars
2023, Arquivos em Odontologia