Glass Ionomer Cements (GIC) have been widely used in clinical practice since they have a wide range of positive characteristics: chemical bonding to the tooth surface, fluoride release, a heat-expansion coefficient similar to the tooth, do not require an absolutely dry working area, less volumetric contraction, good color stability. Physical properties can be improved by using external energy such as ultrasound and radiant heat (thermo-curing), which also accelerates chemical curing. Objectives: The aim of this study was to determine the most effective polishing technique and to compare the surface roughness of two Glass Ionomer Cements after treatment with heat (thermo-curing), and without heat treatment during the setting process. Materials and methods: Two polishing systems (Tungsten carbide burs and Sof-Lex discs) were used on two types of GIC (Equia Fil and Ketac Molar Universal). Bluephase 16i LED (Vivadent, Schaan Liechtenstein) light was used for the specimens treated with heat (thermo-curing). Samples without heat treatment are left for 10 minutes to chemically cure. Surface profilometar was used for measuring the mean surface roughness value (Ra). Results: Group with Mylar strip (control group) of each material showed the lowest (Ra) value. The Equia Fil material samples treated with heat (thermo-curing) achieved lower surface roughness values (Ra), and showed lower surface roughness values (Ra) after polishing with a Sof-Lex discs (p0.05) between polishing with Sof-Lex discs and Tungsten carbide burs. Conclusion: Based on the obtained results, it can be concluded that the smoothest surface roughness is achieved by the Mylar strip. Some types of Glass Ionomer Cements can obtain better surface polishing with heat treatment (thermo-curing).
Background: The microleakage of a self-adhesive composite, a glass ionomer fissure sealant and a conventional resin-based fissure sealant were compared. Materials and methods: Fifty intact human molars with well-delineated pits and fissures were used and divided into 5 groups (n = 10). Group 1 specimens were etched (37% phosphoric acid) and sealed with conventional resin-based sealant (Helioseal F, Ivoclar Vivadent). Both Group 2 and 3 specimens were sealed with self-adhesive composite (Constic, DMG), but in Group 3, specimens were also etched (37% phosphoric acid). In Groups 4 and 5, specimens were sealed with a GIC sealant (Equia Fill, GC Company), but Group 5 was also exposed to thermo-light curing (TLC) with a LED polymerization unit (60 s). Subsequently, specimens were thermocycled (1800 cycles, dwelling time of 10 s), immersed in 50% silver nitrate solution (45 min), placed in a photo-developing solution (Kodak) under a lamp (120 W, 6 h), and cut into 3–4 slices. Marginal leakage (dye penetration depth) was evaluated under a light microscope and the worst score of each specimen was recorded (0–3). Results: Constic showed the lowest microleakage (Constic: 80% scored 0 or 1), followed by Helioseal (30% scored 0 or 1) (p = 0.037). Microleakage in groups sealed with Constic (with and without etching) were not different (p = 0.473). The quality of seal deteriorated after etching when Constic was used. However, TLC improved the seal when GIC sealant was used (p = 0.016) and also in comparison to Helioseal (p = 0.004). The TLC GIC sealant (Equia Fill, 90% scored 0 or 1) performed well, similar to self-adhesive composite (Constic, 80% scored 0 or 1) (p = 0.206). Conclusion: The present findings suggest that the self-adhesive sealant and the GIC sealant that were exposed to TLC had comparable sealing ability and superior sealing characteristics compared to the conventional resin-based sealant. A long-term clinical trial is needed to assess the intra-oral performance.
This aim of this study was to investigate surface gloss changes of different composite dental materials after chemical degradation or polishing. Five different composites were used (Evetric, GrandioSO, Admira Fusion, Filtek Z550, Dynamic Plus). The gloss of the tested material was measured with a glossmeter before and after chemical degradation in different acidic beverages. Statistical analysis was performed using a t-test for dependent samples, ANOVA, and a post hoc test. For comparison between groups, a level of significance was set at 0.05. Initial gloss values ranged from 51 to 93 at baseline to 32 to 81 after chemical degradation. The highest values were obtained for Dynamic Plus (93.5 GU) and GrandioSO (77.8 GU), followed by Admira Fusion (82 GU) and Filtek Z550 (70.5 GU). Evetric showed the lowest initial gloss values. After acidic exposures, the gloss measurements revealed different patterns of surface degradation. The results showed that the gloss of the samples decreased with time regardless of the treatment. The interaction between chemical-erosive beverages and the composite could lead to a decrease in the surface gloss of the composite restoration. The nanohybrid composite showed less gloss changes under acidic conditions, suggesting that it is more suitable for anterior restorations.
The application of the Glass Ionomer Cements in clinical dentistry is recommended due to properties such as fluoride release, chemical adhesion to tooth, negligible setting shrinkage, and coefficient of thermal expansion close to tooth, low creep, and good color stability. However, the cement is vulnerable to early exposure to moisture due to slow setting characteristics. The uses of external energy such as ultrasound and radiant heat (Thermo-curing) have been reported to provide acceleration of the setting chemistry and enhance physical properties. Aim: The aim of this in vitro study was to analyze temperature changes in the pulpal chamber when using radiant heat to accelerate the setting of GICs. Material and Methods:The encapsulated GIC Equia Forte was used for this study. The temperature changes in the pulp were measured using thermocouple in the cavities which were 2,6 and 4,7mm deep with and without filling. Results:The results showed that a temperature rise (ΔT) in the pulp chamber was 3,7°C. ΔT for the 2.6mm and 4.7mm deep cavity and without placing any restoration the temperature was 4,2°C and 2,6°C respectively. After the restoration has been placed, the ΔT range in the pulp chamber was lower ranging from 1.9°C to 2.4°C. Conclusion: It could be concluded that Thermo-curing of the GIC during the setting is safe for the pulp and can be recommended in clinical practice.
The results of orthodontic therapy largely depend, among other factors, on the preparation of the tooth enamel itself and the choice of material used to bond orthodontic brackets. The aim of this in vitro study was to determine the shear bond strength (SBS) and adhesive remnant index (ARI) score of thermo-cured glass–ionomers on different pretreated enamel, in comparison with the commonly used composite cement. Three commercially available nano-ionomer or highly viscous glass–ionomer cements (EQUIA Forte® Fil, EQUIA Fil, Ketac Universal) and two types of compo-sites (Heliosit Orthodontic, ConTec Go!) were investigated in this study. The research involved two hundred human premolars. The teeth were cleaned and polished, then randomly divided into five groups according to the enamel preparation method and the type of material. The enamel was treated in three different ways: polyacrylic acid, phosphoric acid, 5% NaOCl + etching with phosphoric acid, and a control group without treatment. Glass–ionomer cement was thermo-cured with heat from a polymerization unit during setting. Statistical analysis was performed using a Chi-square test and one-way ANOVA for independent samples. Spearman’s Rho correlation coefficient was used to examine the relationship. Regardless of the material type, the results indicated that the weakest bond between the bracket and tooth enamel was found in samples without enamel pretreatment. The majority of the materials stayed on the brackets in samples without enamel preparation, according to ARI scores. The study’s findings demonstrated that the strength of the adhesion between the bracket and enamel is greatly influenced by enamel etching and glass–ionomer thermo-curing. Clinical investigations would be required to validate the outcomes.
Aim: The increasing popularity of do-it-yourself (DIY) tooth whitening using natural products has raised concerns regarding their effectiveness and potential adverse effects on enamel. This in vitro study aimed to compare the colour changes produced by selected commercially available household products and preparations promoted for DIY tooth whitening and to evaluate their influence on enamel surface roughness. Materials and Methods: Thirty extracted human teeth were stained with coffee and black tea and randomly assigned to five groups (n = 6): activated charcoal, baking soda, coconut oil, turmeric, and a lemon juice–baking soda mixture. Specimens were brushed twice daily for 14 days using an electric toothbrush. Tooth colour was measured at baseline (T0), after 7 days (T1), and after 14 days (T2) using a digital spectrophotometer (CIE Lab* system). Colour change (ΔE), bleaching index, and enamel surface roughness (Ra) were assessed. Data were analysed using ANOVA with Tukey post hoc tests and Pearson correlation analysis (p < 0.05). Results: All tested agents produced perceptible colour changes (ΔE > 3.3) after 7 and 14 days. Significant differences in colour parameters and the bleaching index were observed among groups over time (p ≤ 0.001). Activated charcoal produced the largest overall colour change; however, none of the tested agents fulfilled the directional criterion for true whitening (increased L* with decreased b*). Enamel surface roughness increased significantly over time; however, no statistically significant agent-specific effect was demonstrated. Likewise, no statistically significant correlations were found between post-treatment surface roughness and the evaluated colour parameters or the bleaching index.