Surface treatments and coatings of hybrid glass ionomer cement to improve mechanical and physical properties

Q: Which surface treatments were tested for the hybrid glass ionomer cement in this study?

Six treatments were evaluated, including a proprietary light-cured coat, a bonding agent, light curing alone for 20s or 60s, petroleum jelly, and an untreated control.

Q: How were flexural strength and fluoride release measured over time?

Flexural strength was measured using a three-point bend test (ISO 4049:2019). Fluoride release was assessed at 24, 48, 96 hours and 28 days, with sorption and solubility measured at 28 days.

Q: What treatments most improved minimum required strength and fluoride release?

The proprietary coat and bonding agent reached the minimum required strength (MRS = 80 MPa) fastest (under 2 days). The control showed the highest fluoride release initially, while 60s light curing released the most fluoride at 28 days.

Q: Did the study find differences in water sorption or solubility among treatments?

No significant differences in water sorption or solubility were found across the tested surface treatments.

Sep 30, 2026

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In vitro evaluation of a high-viscosity hybrid glass ionomer cement (HVGIC, Equia Forte HT) over 28 days assessed flexural strength, fluoride release, water sorption, and solubility after six surface treatments. Specimens were stored in artificial saliva at 37°C, with flexural strength measured by three-point bending (ISO 4049:2019) and fluoride release tracked at 24, 48, 96 h and 28 days; sorption and solubility were measured at 28 days. Proprietary coat and bonding agent achieved the fastest minimum required strength, control showed the highest early fluoride release, and 60s light-curing released most fluoride at day 28. No significant differences were observed for sorption or solubility, supporting coatings or prolonged curing to improve HVGIC performance and restoration longevity.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages11

Reading Time28 min

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Surface treatments and coatings of hybrid glass ionomer cement to improve mechanical and physical properties

Experimental design and outcome measures

Effects of different surface treatments on strength and fluoride release

Background on glass ionomer cements and moisture-related limitations

Rationale for protective coatings and delayed moisture exposure

[www. nature.com/scientificreports](www. nature.com/scientificreports) OPEN Surface treatments and coatings of hybrid glass ionomer cement to improve mechanical and physical properties G. Zambon1,2􀀍, M. G. Cagetti1, S. Cirio1, G. De Bortoli1,2, A. Allam1 & A. C. Ionescu2,3 This in vitro study evaluated the flexural strength, fluoride release, water sorption, and solubility of a high-viscosity hybrid glass ionomer cement (HVGIC, Equia Forte HT, GC Europe) over 28 days following six surface treatments: Equia Forte Coat (light-cured, 20s), bonding agent (Clearfil SE Universal Bond, 20s), light-curing alone as thermal treatment (20s or 60s), petroleum jelly, and untreated control. Specimens were stored in artificial saliva at 37 °C. Flexural strength (three-point bend test, ISO 4049:2019) and fluoride release were assessed at 24, 48, 96 h and 28 days. Sorption and solubility were measured at 28 days. Statistical analysis included bivariate tests, Kaplan-Meier survival curves, Tukey’s post-hoc, and Weibull regression. Proprietary coat and bonding agent reached the minimum required strength (MRS = 80 MPa) fastest (< 2 days), followed by petroleum jelly (2.5 days), 60s light curing (3 days), 20s (4 days), and control (5.5 days). Control showed the highest fluoride release initially, while at 28 days, 60s light-curing released the most fluoride. Proprietary coat and bonding agent showed minimal release. No significant differences in water sorption or solubility were found. These findings suggest that specific coatings or prolonged light curing can improve HVGIC performance and longevity of restorations. First introduced in 19721, glass-ionomer cements (GICs) are still widely used in restorative dentistry. Application of GIC include full restorations for both primary and permanent teeth, fissure sealants, liners and bases, luting agents, and adhesives for orthodontic brackets2. Their properties of simple handling, good biocompatibility to pulp and surrounding tissue3, downregulating bacterial acidic metabolism4, adhesion to the tooth surface5, and fluoride release & recharge6,7 have contributed to their popularity. All GICs are the result of a chemical setting reaction that occurs between glass ions (silica, alumina, fluoride, aluminum fluoride, strontium, together with minimal percentages of sodium, calcium, and others) and an aqueous solution of carboxylic acids. Upon mixing the liquid and powder components, a rapid acid-base reaction is initiated, lasting approximately 2–10 min and resulting in the formation of an ionically crosslinked polysalt matrix8. Subsequently, a secondary acid-base reaction phase ensues, characterized by the gradual release of cations (mainly calcium, aluminum, strontium) into the matrix, which continues for up to 24 h9. During the initial setting phase, the material exhibits high susceptibility to water sorption. Early contact with moisture causes loss of ions from the surface of the material, leading to surface erosion10. In the following maturation phase, the material becomes particularly vulnerable to dehydration. These moisture-related sensitivities can adversely affect the material’s mechanical properties, resulting in decreased flexural strength and increased wear of the restorations11, 12. Also, water loss can cause microcracks, volume variations and adhesion deficiency. More modern GIC restorative materials, including hybrid GICs, incorporate finer, highly-reactive glass particles and an increased length of the polyacrylic acid chains13. This formulation optimized the mechanical performance of the material, improving the well-known drawbacks ofthe material such as its flexural strength, wear resistance, and aesthetic properties14–16. Even so, the long-term mechanical performance of hybrid GICs remains significantly inferior to that of resin-based composites, particularly in terms of durability and resistance to occlusal stresses17. 1Department of Biomedical, Surgical, and Dental S

FAQs

Which surface treatments were tested for the hybrid glass ionomer cement in this study?

Six treatments were evaluated, including a proprietary light-cured coat, a bonding agent, light curing alone for 20s or 60s, petroleum jelly, and an untreated control.

How were flexural strength and fluoride release measured over time?

Flexural strength was measured using a three-point bend test (ISO 4049:2019). Fluoride release was assessed at 24, 48, 96 hours and 28 days, with sorption and solubility measured at 28 days.

What treatments most improved minimum required strength and fluoride release?

The proprietary coat and bonding agent reached the minimum required strength (MRS = 80 MPa) fastest (under 2 days). The control showed the highest fluoride release initially, while 60s light curing released the most fluoride at 28 days.

Did the study find differences in water sorption or solubility among treatments?

No significant differences in water sorption or solubility were found across the tested surface treatments.

Sep 30, 2026

Upload by Levi