Properties of New Glass-Ionomer Restorative Systems Marketed for Stress-Bearing Areas

Abstract

SUMMARY Objectives: The purpose of this study was to evaluate the properties (fracture toughness, surface hardness) of newer conventional glass-ionomer restorative materials that are marketed for posterior stress-bearing areas compared with more traditional glass-ionomer restorative materials marketed for non–load-bearing areas and composite-resin restorative materials. Methods and Materials: Notched-beam fracture toughness specimens were created in a mold with each tested material (Equia Forte, GC America, with and without a surface coating of Equia Forte Coat; Ketac Universal, 3M/ESPE; ChemFil Rock, Dentsply; Fuji IX GP Extra, GC; Ionostar Molar, VOCO; Filtek Z250, 3M/ESPE; Filtek Supreme Ultra, 3M/ESPE) and fractured using a universal testing machine after 24 hours of storage. Hardness values were determined on the surface of the fracture toughness specimens using a hardness tester. Data were analyzed with a one-way ANOVA and Tukey's post hoc test per property (alpha=0.05). Results: The composite-resin restorative materials had significantly greater fracture toughness than the glass-ionomer materials. There was no significant difference in fracture toughness between the glass-ionomer materials. The use of a resin coating significantly increased the surface hardness of the newer glass ionomer marketed for stress-bearing areas. Conclusions: Fracture toughness was not improved with the newer glass-ionomer restorative materials marketed for stress-bearing areas compared to the conventional glass-ionomer materials, however a resin coating provided greater surface hardness.

Bulk-Fill Direct Restorative Materials: An In Vitro Assessment of Their Physio-Mechanical Properties

“…Among the coating strategies, Hotta et al found that the application of light-polymerised bonding agents helped to limit water movement across cement surface, especially within the first month of maturation [21]. This clear, self-adhesive, light-cured resin EQUIA Forte coat has single dispersion nanofillers in the matrix and a new cross linking monomer chemistry, rendering improved polymerisation, producing a tougher resin matrix [12]. This coating is speculated to toughens and protects the EQUIA Forte restorative system by infiltrating the GIC surface, thus filling cracks and porosities [35].…”

“…Unfortunately, their use was limited, due to their relatively low tensile strength, abrasion resistance, hardness and poor aesthetics [11]. A recently enhanced version of high viscosity glass ionomer cement, known as EQUIA Forte Fil (GC Corporation, Tokyo, Japan), was promoted for use as a bulk-fill restorative material in class I and II cavity design in the posterior region [12]. EQUIA Forte consists of higher molecular weight polyacrylic acid to create a high strength material, resulting in a bulk-fill glass hybrid restorative structure with improved aesthetics and physical properties [11].…”

Quality of approximal surfaces of posterior restorations in primary molars

“…This sensitivity to water contamination and dehydration is restricted by the application of a resin coating [22,30]. However, in the case of Ketac Universal, no benefit has been reported [21,22]. Moreover, when the matrices were removed, remnants of the cement could be observed attached to them.…”

“…They can also be placed in one increment and offer an alternative to resin composite when it is difficult to properly isolate teeth, as they are less sensitive to humidity [7]. Unlike, early glass ionomer cements, new reinforced formulations have been developed by modifying the powder/liquid proportion and powder particle size distribution [19,20], and it is claimed that they can be used for restricted stress-bearing Class I and II restorations [10,21]. In this regard, some of the recently launched high-viscosity glass ionomer cements (HVGICs) do not require conditioning of the dental tissues prior to their placement, or protective varnishes to improve their mechanical properties [22].…”

Application of Texture and Fractal Dimension Analysis to Evaluate Subgingival Cement Surfaces in Terms of Biocompatibility

“…Glass ionomers were first introduced in 1978 as aluminosilicate poly acrylic cement (ASPA), which can be specifically applied in atraumatic treatment [ 6 ]. The most valuable features of glass ionomer cement include fluoride release [ 14 ], the coefficient of thermal expansion compatible with tooth tissues [ 15 ], the possibility to use them in cavities without the need for bonding agents [ 16 ], and the formation of direct chemical adhesion to the tooth structure [ 17 ]. On the other hand, the lack of sufficient strength and toughness seem to constitute the most important disadvantages of glass ionomers [ 18 ].…”