This study aimed to develop resin coatings containing monocalcium phosphate monohydrate (MCPM), Sr/F-doped bioactive glass (Sr/F-BAGs), and pre-reacted glass ionomer fillers (SPG) that enhance ion release without detrimentally affecting the mechanical properties of GIC. The objective of this study was to evaluate the degree of monomer conversion (DC), biaxial flexural strength, surface microhardness, and ion release of the GICs coated with experimental coating materials compared to a commercial product (EQUIA Coat, EC). Four experimental resin coating materials containing 10-20 wt% of MCPM with Sr/F-BAGs and 5-10 wt% SPG were prepared. The DC of the coating material was determined using ATR-FTIR. The flexural strength and surface microhardness of the coated GICs were assessed. Fluoride and elemental (Ca,P,Sr,Si,Al) release were measured using fluoride-specific electrodes and ICP-OES. The DC of the experimental coating material (60-69 %) was higher than that of EC (55 %). The strength of GICs coated with experimental materials (35-40 MPa) was comparable to EC (37 MPa). However, their surface microhardness (13-24 VHN) was lower than EC (44 VHN). The experimental coating materials reduced fluoride release by ∼43 %, similar to EC (∼40 %). However, experimental coating materials promoted higher P and Sr release than EC. In conclusion, GICs coated with the experimental resin coating containing ion-releasing additives exhibited mechanical properties similar to those of the commercial product. The new coating materials promoted a higher level of ion release for GICs. These properties could potentially enhance remineralizing actions for the coated GICs.

OBJECTIVE: To investigate the effects of erbium laser pretreatment on the bond strength of dentin and enamel,as well as microleakage at the edge of tooth defects repaired with computer-aided design (CAD) and computer-assisted manufacturing (CAM) glass-ceramic restorations for repairing dental defects.
METHODS: A total of 62 fresh, nondecayed, nondiscoloration and noncracked wisdom teeth were collected from the Oral Surgery Clinic between January 2020 and January 2023. According to different pretreatment methods, they were randomly divided into two groups, erbium laser group and phosphoric acid group, with 31 teeth in each group. Each group was further divided into two subsets for bond strength testing (16 teeth) and microleakage testing (15 teeth).The shear bond strength between enamel and dentin of both groups was compared, as well as the degree and distribution of microleakage.Statistical analysis was performed with SPSS 17.0 software package.
RESULTS: The shear bond strength between enamel and dentin of the erbium laser group was significantly higher than that of the phosphoric acid group (P＜0.05); the degree and distribution of microleakage at the lateral walls and gumline of the erbium laser group were significantly lower than those of the phosphoric acid group (P＜0.05). The scores of microleakage at the lateral walls of the erbium laser group mainly concentrated in grade 1 and 2, whereas those of the phosphoric acid group mainly concentrated in grade 2. There was significant difference in the distribution of lateral wall microleakage scores between the two groups (P＜0.05). The scores of microleakage at the gumline of the erbium laser group mainly concentrated in grade 1 and 2, whereas those of the phosphoric acid group mainly concentrated in grade 2 and 3. There was significant difference in the distribution of gumline microleakage scores between the two groups (P＜0.05).
CONCLUSIONS: Erbium laser pretreatment can improve bonding strength between glass ionomer cement and dentin and enamel, reduce microleakage at the edge of CAD/CAM glass ionomer cement restorations, and enhance marginal fit.

This (in vitro) investigation was conducted to evaluate PH value and antibacterial effect of Alkasite restorative materials against important oral pathogens Streptococcus mutans and lactobacillus plantarum.
METHODS: Four groups were made of three different type ion releasing materials Cention N= group 1, Primer free Cention Forte=group 2, Primer applied Cention Forte=group 3 and Fuji IX= group 4. A total number of 72 discs in form samples (2 mm height and 5mm diameter) were constructed in polyethylene mold divided according to the evaluating parameters. 32 specimens for PH measurements (n=8) and 40 specimens were utilized for antibacterial effect (n=5) for each bacterial species. The antibacterial properties of groups were assessed by direct contact test. An adjusted diluted broth culture of each bacterium (Streptococcus mutans) and (Lactobacillus plantarum) were prepared.
RESULTS: At all intervals of time both Cention N and Primer free Cention Forte has significantly higher PH value in comparison with Fuji IX. Primer applied Cention Forte. There was no significant difference between Cention N, Primer free Cention and Fuji IX in terms of their effect in reducing viable colony count in both bacterial species.
CONCLUSIONS: Along period of (28day) Alkasite material groups (Cention N and Primer free Cention Forte) showed the ability to increase the storage solution PH value. Also, both groups have antibacterial effect against (Streptococcus mutans) and (Lactobacillus plantarum) by inhibiting their numbers. Applying Cention primer showed negative effect on both PH value and the antibacterial effect of the material.

Glass ionomer cements (GICs) are the common materials employed in pediatric dentistry because of their specific applications in class I restorations and atraumatic restoration treatments (ART) of deciduous teeth in populations at high risk of caries. Studies show a limited clinical durability of these materials. Attempts have thus been made to incorporate nanoparticles (NPs) into the glass ionomer for improving resistance and make it like the tooth structure. An in vitro experimental study was conducted using the required samples dimensions and prepared based on the test being carried out on the three groups with or without the modification of light-cured glass ionomer. Samples were grouped as follows: control group (G1_C), 2% silver phosphate/hydroxyapatite NPs group (G2_SPH), and 2% titanium dioxide NPs group (G3_TiO2). The physical tests regarding flexural strength (n = 10 per group), solubility (n = 10 per group), and radiopacity (n = 3 per group) were performed. The data were analyzed by Shapiro Wilks test, and one-way analysis of variance (one-way ANOVA), and multiple comparisons by post hoc Tukey\'s test. The p-value of < 0.05 was considered significant. No statistically significant difference was observed between the control group (G1_C) and (G2_SPH) (p = 0.704) in the flexural strength test, however differences were found between G2_SPH and G3_TiO2 groups, ANOVA (p = 0.006); post hoc Tukey\'s test (p = 0.014). Pertaining to the solubility, G2_SPH obtained the lowest among the three groups, ANOVA (p = 0.010); post hoc Tukey\'s test (p = 0.009). The three study groups obtained an adequate radiopacity of >1 mm Al, respectively. The resin-modified glass ionomer cement (RMGIC) was further modified with 2% silver phosphate/hydroxyapatite NPs to improve the physical properties such as enhancing the solubility and sorption without compromising the flexural strength and radiopacity behavior of modified RMGIC. The incorporation of 2% titanium dioxide NPs did not improve the properties studied.

UNASSIGNED: Endodontic treatment is the most common method for resolving pulpal and periapical pathology. However, various studies have reported that almost 11%-13% of all teeth that undergo extraction after endodontic treatment show the presence of cracks, craze lines, and vertical root fractures. Teeth with inadequate post endodontic restoration are more prone to fracture and coronal leakage, resulting in the diffusion of oral fluids, bacteria, bacterial products, and possibly root canal treatment failure. Furthermore, studies have advocated the use of endodontically treated teeth with restorative materials that have a similar or higher elastic modulus than the tooth for providing stiffness against forces that cause root fracture. Intraorifice barriers made of restorative materials that can bond to radicular dentin could thus be used to reinforce the radicular dentin while also preventing coronal microleakage. Although the sealing ability of intraorifice barriers has been widely compared in the literature, there have been few studies on the strengthening effect of the materials used in the study as intraorifice barriers when placed into the root canal. As a result, the current in vitro study aims to assess the effect of various materials as intraorifice barriers (Cention N, Resin modified glass ionomer cement, and short fiber reinforced flowable composite) on the force required fracture teeth after root canal treatment.
UNASSIGNED: This in vitro study will be done on extracted human mandibular premolars with single root canal where after doing root canal treatment 2-3 mm obturating material would be replaced by intra orifice barriers (Cention N, resin modified glass ionomer cement [RMGIC], and short fiber reinforced flowable composite). The force required to fracture teeth will be calculated using universal testing machine.

OBJECTIVE: To assess the fluoride and silver ion release of glass ionomer cement (GIC) restorations, including conventional GIC (CGIC) and resin-modified GIC (RMGIC) restorations, with 38 % silver diamine fluoride (SDF) solution dentin pretreatment.
METHODS: Eighty dentin blocks were allocated into 4 groups and restored with SDF+CGIC, CGIC, SDF+RMGIC and RMGIC, respectively. Each block was stored in deionized water at 37 °C for 2 years. Fluoride and silver ion concentration in storage solution was measured using ion-selective electrode and inductively coupled plasma-optical emission spectrometry for up to 2 years. The cross-sectional surfaces of restored dentin blocks were assessed by X-Ray diffraction analysis (XRD), scanning electron microscope (SEM) with energy-dispersive X-ray spectroscopy (EDS) after 1 week and 2 years, respectively.
RESULTS: The mean ± standard deviation (SD) of accumulative fluoride releasing in SDF+CGIC, CGIC, SDF+RMGIC and RMGIC for 2 years were 0.13±0.005 mg, 0.09±0.006 mg, 0.15±0.008 mg and 0.05±0.003 mg, respectively (Groups SDF+RMGIC > SDF+CGIC > CGIC >RMGIC, p < 0.05). The mean ± SD of accumulative silver releasing in SDF+CGIC, CGIC, SDF+RMGIC and RMGIC for 2 years were 0.03±0.009 mg, 0.00±0.00 mg, 0.01±0.003 mg, and 0.00±0.00 mg, respectively (Groups SDF+CGIC > SDF+RMGIC > CGIC&RMGIC, p < 0.05). Groups SDF+CGIC and SDF+RMGIC showed sustainably higher fluoride and silver releasing compared to Groups CGIC and RMGIC (p < 0.05). XRD analysis indicated the fluorapatite and silver chloride were observed only in Groups SDF+CGIC and SDF+RMGIC, but not in Groups CGIC and RMGIC. SEM images of the cross-sectional view of the dentin blocks showed silver crystals within dentinal tubules 1 week and 2-year in Groups with SDF pretreatment.
CONCLUSIONS: The 38 % SDF dentin pretreatment sustainably increased the fluoride and silver release of GIC and RMGIC restorations for up to 2 years.

To investigate the effect of decontamination procedures on the microshear bond strength (μSBS) of blood-contaminated resin-modified glass ionomer cement (RMGIC) bonded to resin composite (RC).
Eighty RMGIC disc specimens were allocated into 5 groups (n=16). All groups except Group 2 were contaminated with blood. Group 1 had no decontamination procedure, Group 3 was decontaminated by rinsing, Group 4 was decontaminated by 34% phosphoric acid etching, and Group 5 was decontaminated by 5% sodium hypochlorite application. RMGIC specimens were subsequently bonded with RC using a universal adhesive in self-etch mode. μSBS tests were conducted using a universal testing machine at a crosshead speed of 1 mm/min. Failure mode analysis was conducted on RMGIC fracture surfaces under a scanning electron microscope.
μSBS results indicated that Group 4 had the highest mean μSBS value of 6.22 ± 2.14 MPa, while Group 1 had the lowest mean μSBS value of 3.53 ±1.67 MPa. Significant differences were observed in the μSBS of Group 2 with no contamination (p=0.023) and Group 4 with decontamination by phosphoric acid-etching (p=0.003) when compared to Group 1 with blood contamination. No statistically significant differences (p>0.05) were observed between all other groups\' μSBS. For all groups, the predominant mode of failure was adhesive failure between the RMGIC-RC interface, with a few mixed failures in RMGIC for Groups 2-5.
Blood contamination before adhesive application significantly reduced the μSBS between RMGIC and RC. Phosphoric acid etching was the most effective blood decontamination procedure to improve the μSBS.

OBJECTIVE: The aim of the study was to compare and evaluate the microleakage of fiber-reinforced glass ionomer cement (GIC) and conventional glass ionomer cement restorations immersed in three different beverages.
METHODS: A total of 96 human exfoliating deciduous molars were selected which were cleaned and disinfected. Standardized Class V cavity preparations were done and buccal surface were restored with experimental fiber-reinforced glass ionomer cement (Exp-FRGIC), lingual surface were restored with Type II conventional GIC. They were divided into four groups according to the test beverage. The samples were subjected to various immersion regimes and evaluated for microleakage under stereomicroscope.
RESULTS: Intragroup comparison for (Exp-FRGIC) showed significant microleakage when immersed in fresh fruit juice at high immersion whereas intragroup comparison in conventional GIC, showed highest microleakage with soft drink. Intergroup comparison of (Exp-FRGIC) in high immersion regime, showed more microleakage with specimen immersed in soft drink followed by fresh fruit juice.
CONCLUSIONS: It can thus be concluded that the three beverages used in the study affected the microleakage of both restorative materials significantly.
CONCLUSIONS: Increasing usage of fruit juices in the pediatric diet has a definite impact on the progression of caries and it directly or indirectly affects the quality of restorations placed in the oral cavity. How to cite this article: George MA, Chandak SA, Khekade SH, et al. Comparative Evaluation of Microleakage of Fiber-reinforced Glass Ionomer Cement and Conventional Glass Ionomer Cement Restorations Immersed in Three Different Beverages: In Vitro Study. J Contemp Dent Pract 2024;25(4):346-353.

BACKGROUND: Despite the superiority of glass-ionomer cements (GICs) over composites in treating white spot lesions (WSLs), there is still a concern about their preventive and antibacterial properties. Efforts have been made to improve the strength of their bond to demineralized enamel, fluoride release and antibacterial properties by adding nanoparticles of chitosan, which seems to be a promising method.
OBJECTIVE: The aim of the present study was to assess the antibacterial effect, the microshear bond strength (μSBS) to enamel at the WSL area, and the fluoride and nano-chitosan release after modifying the polyacrylic acid liquid phase of a traditional GIC with different nano-chitosan volumes.
METHODS: A total of 120 samples were prepared, and then divided into 4 groups (n = 30): G1 - non-modified GIC, which served as a control group, while G2, G3 and G4 were modified with different nano-chitosan volumes (50%, 100% and 150%, respectively). Microshear bond strength was assessed using a universal testing machine (UTM) after storage in distilled water for 24 h. Fluoride and nanochitosan release was measured with the use of spectrophotometers at different time points (initially, and at 1 h, 24 h, 48 h, 72 h, 1 week, 2 weeks, 3 weeks, and 6 weeks) after storage in distilled water. The antibacterial effect against the Streptococcus aureus strain was assessed with the agar diffusion test. The data was statistically analyzed.
RESULTS: After 24-hour storage, G2 recorded a slight, yet non-significant, increase in the μSBS values (4.1 ±0.94 MPa) as compared to G1 (3.9 ±1.30 MPa). With regard to fluoride release, the amount recorded for G1 was significantly greater at the end of the 24-hour storage period (0.70 ±0.30 μmf/cm2) than modified nano-chitosan GIC groups; G1 was followed by G4 (0.54 ±0.34 μmf/cm2). The highest amount of nano-chitosan release after 24-hour storage was noted for G3 (0.85 ±0.00 μmf/cm2). The highest inhibition zone value was recorded for G2.
CONCLUSIONS: Glass-ionomer cement modified with 50% nano-chitosan was shown to positively affect μSBS and the antibacterial effect, while modification with 150% nano-chitosan significantly increased fluoride release.

OBJECTIVE: The aim of this study was to evaluate the effect of proanthocyanidin and C. sinensis-polyphenols on microtensile bonding properties of prepared teeth with resin-modified glass ionomer cement (GIC).
METHODS: This was an in vitro study.
METHODS: Seventy-eight maxillary premolars were selected and mounted into auto-polymerizing acrylic resin blocks. The samples were prepared and metal crowns were fabricated. The samples were randomly divided into three groups. Samples under Group 1 were not treated with any of the extracts and followed conventional bonding protocol. Samples under Group 2 and Group 3 were treated with proanthocyanidin and C. sinensis-polyphenols, respectively. After dentin treatment, these samples were luted to metal crowns using resin-modified GIC. Universal testing machine was used to measure the load at which the crowns were debonded and microtensile bond strength in MPa was calculated.
METHODS: The results were statistically analyzed using one-way ANOVA and post hoc Tukey HSD.
RESULTS: Samples treated with C. sinensis polyphenols (Group 3) had maximum bond strength followed by Group 2, where the samples were treated with proanthocyanidin.
CONCLUSIONS: C. sinensis polyphenols due to their anti-proteolytic and antioxidant properties showed improved bond strength compared to proanthocyanidin, a cross-linking agent, followed by conventional bonding protocol.