Conventional Glass Ionomer Cement Research Articles

Comparative Evaluation of Antimicrobial Effectiveness and Compressive Strength in Neem and Lemongrass-Modified Glass Ionomer Cement: An In Vitro Study.

Background Glass ionomer cement (GIC) demonstrates biocompatibility and fluoride ion release, indicating their potential to inhibit a wide range of bacteria, although this remains uncertain. Lemongrass and neem are recognized for their potent antimicrobial activity against numerous pathogenic microorganisms. The objective of the study is to evaluate the antimicrobial effectiveness and compressive strength of GIC modified with neem and lemongrass. Methodology Lemongrass and neem were incorporated into conventional GIC at varying concentrations. Group I - neem-modified GIC (0.5%, 1%, 2%), group II - lemongrass-modified GIC (0.5%, 1%, 2%), and group III (non-modified GIC as a control group). The disk-shaped specimens were then compared to unmodified GIC (control). Antimicrobial effectiveness was assessed using the minimal inhibitory concentration (MIC) assay against Streptococcus mutans and Lactobacillus. Compressive strength was assessed using a Universal Testing Machine, with a crosshead speed set to 0.5 mm per minute. Statistical analysis was conducted with a significance level set at p < 0.05. Results Neem modification displayed superior antimicrobial effectiveness against both Streptococcus mutans and Lactobacillus at all concentrations when compared to the control, with 2% showing the least mean value of 0.262. In contrast, lemongrass modification exhibited a significant difference in effectiveness against Streptococcus mutans but no difference against Lactobacillus. Neem modification demonstrated superior performance compared to lemongrass (p < 0.05). Both modified groups showed no significant impact on compressive strength. Conclusions Neem-modified GIC demonstrated the highest antimicrobial efficacy against Streptococcus mutans and Lactobacillus without altering its compressive strength. This suggests its potential as a promising alternative material in restorative dentistry. Additional in vivo investigations are needed to assess the extended-term effectiveness of the material.

Assessing the Influence of Thermocycling on Compressive Strength, Flexural Strength, and Microhardness in Green-Mediated Nanocomposite-Enhanced Glass Ionomer Cement Compared to Traditional Glass Ionomer Cement.

Background and objective Glass ionomer cement (GIC), also known as polyalkenoate cement, has been extensively used in dentistry for both luting and restorative purposes. Despite being the first choice for aesthetic restorations due to their chemical bonding ability to teeth, GICs have faced challenges such as low mechanical properties, abrasion resistance, and sensitivity to moisture, leading to the search for improved materials. This study aims to assess the effects of thermocycling on the compressive, flexural strength, and microhardness of green-mediated nanocomposite-modified GIC in comparison to traditional GIC. Methodology Green-mediated nanoparticles, consisting of chitosan, titanium, zirconia, and hydroxyapatite (Ch-Ti-Zr-HA), were synthesized using a one-pot synthesis technique to form nanocomposites. These nanocomposites were then incorporated intoGICspecimens in varying concentrations (3%, 5%, and 10%), denoted as Group I, Group II, and Group III, respectively. Group IV served as the control, consisting of conventional GIC. To assess the performance of the novel restorative materials over an extended period, compressive strength, flexural strength, and microhardness were measured before and after thermocycling using a universal material testing machine. Furthermore, scanning electron microscopy (SEM) analysis was carried out following the thermocycling process. The collected data were subjected to statistical analysis through one-way analysis of variance (ANOVA) and paired t-tests. Results The findings demonstrated that, in comparison to the control group, both the mean compressive strength and flexural strength, as well as hardness, were notably higher for the 10% and 5% nanocomposite-modified GIC specimens before and after thermocycling (P< 0.05). Notably, there was no notable difference observed between the 5% and 10% concentrations (P > 0.05). These results suggest that incorporating green-mediated nanocomposites (Ch-Ti-Zr-HA) modified GIC at either 5% or 10% concentration levels leads to improved mechanical properties, indicating their potential as promising alternatives in dental restorative materials. Conclusions Based on our findings, it can be inferred that the 10% and 5% concentrations of green-mediated (Ch-Ti-Zr-HA) modified GIC exhibit superior compressive and flexural strength compared to conventional GIC. Additionally, analysis of the scanning electron microscope (SEM) morphology revealed that green-mediated GIC displays smoother surface characteristics in contrast to conventional GIC. These results underscore the potential advantages of utilizing green-mediated nanocomposite-modified GIC in dental applications, suggesting enhanced mechanical properties and surface quality over conventional.

A Comparative In Vitro Analysis of Antimicrobial Effectiveness and Compressive Strength of Ginger and Clove-Modified Glass Ionomer Cement.

Background Glass ionomer cement (GIC) is widely recognized for its self-adhesive characteristicsand biocompatibility, making it commonly used as a restorative material. However, challenges related to limited antibacterial effectiveness and relatively low mechanical properties have hindered its widespread clinical use. Cloveand ginger are recognized for their potent antimicrobial activity against numerous pathogenic microorganisms. The present study aims to enhance the clinical applicability of GIC by modifying it with clove and ginger extract. Aim The objective of the study is to assess the antimicrobial effectiveness and compressive strength of GIC modified with ginger and clove extract. Materials and methods Ginger and clove extracts were prepared and incorporated into conventional GIC at three concentrations for each, creating ginger-modified GIC groups (Group A, Group B, and Group C) and clove-modified GIC groups (Group D, Group E, and Group F), with Group G as the control (conventional GIC without modification). The antimicrobial assessment was conducted on disc-shaped GIC specimens (3.0 mm height x 6.0 mm diameter) prepared using molds. Bacterial strains were used to evaluate antimicrobial properties, with minimum inhibitory concentration (MIC) assays conducted at intervals of one to four hours for both modified and unmodified groups. Compressive strength specimens were prepared using cylindrical molds (6.0 mm height × 4.0 mm diameter), according to the ISO (International Organization for Standardization) guidelines. The evaluation was conducted using a Zwick universal testing machine (ElectroPuls®E3000, Instron, Bangalore, India), with the highest force at the point of specimen fracture recorded to determine compressive strength. Statistical analysis was conducted utilizing a one-way analysis of variance (ANOVA) alongside Tukey's post hoc test, with a significance threshold set at p < 0.01. Results The antimicrobial effectiveness of clove and ginger-modified GIC was assessed through a MIC assay, revealing a statistically significant improvement in antimicrobial potency against Streptococcus mutans and Lactobacillus within the modified groups compared to the control group (p < 0.01). Increased extract concentration correlated with enhanced antimicrobial activity. Clove-modified GIC exhibited superior antimicrobial efficacy compared to ginger extract. Compressive strength was higher in clove-modified GIC groups (p < 0.01), with Group F showing a maximum value of 175.88 MPa, while other modified groups demonstrated similar results to the control, with a value of 166.81 MPa (p > 0.01). Conclusion The study concludes that both clove-modified GIC and ginger-modified GIC exhibited antimicrobial activity against Streptococcus mutans and Lactobacillus species. The antimicrobial activity was notably higher in clove-modified GIC compared to ginger-modified GIC. Additionally, the compressive strength of clove-modified GIC surpassed all other groups. Thus, clove-modified GIC emerges as a promising restorative material for addressing recurrent caries. Future investigation is necessary to assess the long-term durability of the material.

The Impact of Nano- and Micro-Silica on the Setting Time and Microhardness of Conventional Glass-Ionomer Cements.

The objective of this study was to investigate the effect of the incorporation of 2, 4 or 6 wt% of amorphous nano- or micro-silica (Aerosil® OX 50 or Aeroperl® 300 Pharma (Evonik Operations GmbH, Essen, Germany), respectively) on the net setting time and microhardness of Ketac™ Molar (3M ESPE, St. Paul, MN, USA) and Fuji IX GP® (GC Corporation, Tokyo, Japan) glass-ionomer cements (GICs) (viz. KM and FIX, respectively). Both silica particles were found to cause a non-linear, dose-dependent reduction in setting time that was within the clinically acceptable limits specified in the relevant international standard (ISO 9917-1:2007). The microhardness of KM was statistically unaffected by blending with 2 or 4 wt% nano-silica at all times, whereas 6 wt% addition decreased and increased the surface hardness at 1 and 21 days, respectively. The incorporation of 4 or 6 wt% nano-silica significantly improved the microhardness of FIX at 1, 14 and 21 days, with no change in this property noted for 2 wt% addition. Micro-silica also tended to enhance the microhardness of FIX, at all concentrations and times, to an extent that became statistically significant for all dosages at 21 days. Conversely, 4 and 6 wt% additions of micro-silica markedly decreased the initial 1-day microhardness of KM, and the 21-day sample blended at 4 wt% was the only specimen that demonstrated a significant increase in this property. Scanning electron microscopy indicated that the nano- and micro-silica particles were well distributed throughout the composite structures of both GICs with no evidence of aggregation or zoning. The specific mechanisms of the interaction of inorganic nanoparticles with the constituents of GICs require further understanding, and a lack of international standardization of the determination of microhardness is problematic in this respect.

Investigating the Potential of Acacia nilotica-Enriched Glass Ionomer Cement: An Analysis of Antimicrobial Activity and Compressive Strength.

Background According to existing literature, introducing natural antibacterial agents into glass ionomer cement (GIC) has been associated with potential negative impacts on their strength properties. Hence, this study aims to explore the antibacterial effectiveness of glass ionomer cement enriched with Acacia nilotica and subsequently assess its compressive strength characteristics. Aim The objective of the study is to assess the antimicrobial effectiveness and compressive strength of glass ionomer cement modified with Acacia nilotica. Materials and methods The plant extract was incorporated into the conventional glass ionomer cement in three different proportions (powder GIC: extract: liquid GIC), divided into group I, group II, and group III with ratios of 2:1:1, 3:1:2, and 3:2:1 respectively. Additionally, a control group denoted as group IV was included without any modifications. Subsequently, the specimens were prepared, and their chemical structure was analyzed using Fourier transform infrared spectroscopy (FTIR), followed by testing for antimicrobial activity using the minimum inhibitory concentration (MIC) assay against Streptococcus mutans and Lactobacillus. The assessment of compressive strength was conducted following ISO 9917-1:2007 standards, and the recorded values represent the maximum force the specimen could withstand before fracturing. Results The antimicrobial effectiveness against Streptococcus mutans and Lactobacillus exhibited a notable increase in all modified specimens compared to the control group, with a significance level of p<0.05. Additionally, significant improvements in compressive strength were observed in group III (183.49±2.99) when compared to the remaining groups. The higher concentrations of the plant extract resulted in superior outcomes. Conclusion Therefore, the incorporation of Acacia nilotica into GIC shows promising potential as a restorative material. These investigations can provide valuable insights into the material's performance and durability, contributing to its potential application in dental restorations. Future research is needed to thoroughly investigate the bonding chemistry between Acacia nilotica and GIC, as well as to assess the extent of microleakage.

Comparative Evaluation of the Microleakage of Glass Ionomers as Restorative Materials: A Systematic Review of In Vitro Studies

This study aimed to perform a qualitative synthesis of the available in vitro evidence on the microleakage of commercially available conventional glass ionomer cements (GICs), resin-modified glass ionomer cements (RMGICs), and modified glass ionomer cements with nano-fillers, zirconia, or bioactive glasses. A systematic review was conducted according to the PRISMA 2020 (Preferred Reporting Items for Systematic Review and Meta-Analysis) statement standards. The literature search was performed in Medline (via PubMed), Embase, Web of Science, and Scopus to identify relevant articles. Laboratory studies that evaluated microleakage of GICs, RMGICs, and modified glass ionomer cements with nano-fillers, zirconia, or bioactive glasses were eligible for inclusion. The QUIN risk of bias tool for the assessment of in vitro studies conducted in dentistry was used. After the study selection process, which included duplicate removal, title and abstract screening, and full-text assessment, 15 studies were included. A qualitative synthesis of the evidence is presented, including author data, year of publication, glass ionomer materials used, sample characteristics, microleakage technique and values, and main outcome measures for primary and permanent teeth. Although no statistically significant differences were found in numerous studies, most results showed that RMGICs exhibited less leakage than conventional GICs. All studies agreed that leakage was significantly higher at dentin margins. It was also higher at the gingival margin than at the occlusal margin. Nano-filled RMGICs Ketac N100, Equia Forte, and Zirconomer appear to have less microleakage than conventional GICs and RMGICs. Further investigations using a standardized procedure are needed to confirm the results.

Comparative Analysis of Color Stability and Its Impact on Artificial Aging: An In Vitro Study of Bioactive Chitosan, Titanium, Zirconia, and Hydroxyapatite Nanoparticle-Reinforced Glass Ionomer Cement Compared With Conventional Glass Ionomer Cement.

Background Discoloration affects glass ionomer cement (GIC) color stability due to its brittle nature and microporosity. To counter this, incorporating alternative materials is essential for maintainingcolor stability. Aim This study aims to determine the color stability and gloss of GIC modified with bioactive chitosan, titanium, zirconia, and hydroxyapatite nanoparticles before and after artificial aging. Materials and methods The study was conducted at Saveetha Research Centre, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, located in Chennai, India. Green-mediated chitosan, titanium, zirconia, and hydroxyapatite (Ch-Ti-Zr-HA) nanoparticles were synthesized using the one-pot synthesis technique. Forty-eight disc-shaped specimens were prepared by incorporating the obtained nanoparticles (nanocomposite) into the GIC, with a diameterof 5 mm and thicknessof 2 mm. The specimens were prepared in different concentrations (3%, 5%, and 10%) designated as group I, group II, and group III, respectively. Group IV, serving as the control, consisted of conventional GIC without any modifications. Following preparation, scanning electron microscopy (SEM) and energy-dispersive X-ray(EDX)microanalysisconfirmed sample elements, and the specimens were submerged in distilled water for a duration of 24 hours prior to the commencement of testing. Subsequently, the specimens underwent artificial aging (thermocycling),between temperatures of 5°C and 55°C, for a total of 30,000 cycles, with a 30-second dwell time. Color change and gloss characteristics were assessed both after 24 hours and following thermocycling using a spectrophotometer and glossometer, respectively. The average color change parameter (ΔE)was measured using Adobe Photoshop. The data obtained were subjected to statistical analysis using an unpaired t-test. Results Significant color stability variations were observed post thermocycling (P = 0.001). Group 2 (5%) exhibited minimal delta E difference (0.508 ± 0.105), indicating superior color stability, while group 4 (control) had maximum difference (1.15 ± 0.187), indicating lower stability. Gloss tests confirmed GIC's polishability, where there were significant differences among all the groups. Conclusion It can be concluded that 5% nanoparticle-modified GIC has better color stability and gloss than conventional GIC. Further studies are needed to analyze the color stability and gloss through dentifrices and other beverages.

Total rehabilitation in case of amelogenesis imperfecta

The aim of the treatment of this case was to restore the form, function and aesthetics of all teeth in a patient with amelogenesis imperfecta within the age limit of the disability insurance (IV). Single-tooth zirconia crowns were selected as the treatment of choice and cemented with a conventional glass ionomer cement. For the maintenance of the oral rehabilitation and the protection of the reconstructions a michigan splint was produced and instructed to be carried over night.

A comparative evaluation of fluoride release and rechargeability in conventional GIC (type II), pediatric GIC (type IX), and Cention-N: an in vitro study

A comparative evaluation of fluoride release and rechargeability in conventional GIC (type II), pediatric GIC (type IX), and Cention-N: an in vitro study

Miswak-Infused Glass Ionomer Cement: A Comparative In Vitro Analysis of Antibacterial Efficacy and Compressive Strength.

Glass ionomer cement (GIC) restorations are commonly used in primary dentition, due to their aesthetic appeal, self-adhesive nature, and biocompatibility. However, the material's limited antibacterial activity and inadequate mechanical strength highlight the necessity for modifying the material. The study aims to evaluate and compare the antimicrobial potency and compressive strength of GIC-incorporated Miswak extract with that of conventional GIC. After obtaining the Miswak extract, a modified GICwas formulated by combining the extract with the conventional GIC powder and liquid components, in three different ratios (Powder: Extract and Liquid), Group I (2:1:1), Group II (3:1:2), Group III (3:2:1), and the Group IV as control, which consist of unmodified/conventional GIC. To evaluate and compare the antibacterial efficacy of the modified and unmodified GIC, standard strains of Streptococcus mutans and Lactobacillus were utilized. For each group, the minimal inhibitory concentration (MIC) assay was tested. For the evaluation of compressive strength, cylindrical moulds were utilized in compliance with ISO 9917-1:2007 standards and tested using the universal testing machine (Instron, ElectroPuls®, Bangalore, IND). The highest force exerted at the point of specimen fracture was recorded to calculate the compressive strength values in MPa. The data obtained were analyzed using the StatisticalPackage for the Social Sciences (IBMSPSSStatisticsforWindows,IBMCorp., Version 24.0, Armonk,NY)software. The statistical analysis was conducted utilizing repeated measures of analysis of variance (ANOVA) to calculate the mean MICvalues and compressive strength, with pairwise comparisons assessed using Tukey's post hoc test. The results provedthat the antimicrobial properties of Miswak containing GIC performed better against S. mutans and Lactobacillus with a statistically significant difference when compared with group IV (p<0.05), it has been found that an increase in the concentration of extract increased the antimicrobial potency. Significant results were obtained in compressive strength where GroupII (41.49±3.6) and Group III (15.23±4.96) proved to be weaker than the control (62.69±2.58), while Group I showed no differences from the control group (p>0.05). It can be concluded that Group I was found to be better in terms of both antimicrobial properties and compressive strength, where no significant difference in compressive strength was identified when comparing Group I with Group IV. Thus, the overall study depicts that a lesser concentration of extract can be the best option in terms of good antimicrobial properties without altering its strength. Hence, the Miswak containing GIC could be a promising restorative material; further studies should include considering intraoral variables such as masticatory stress, moisture levels and in-vivo tests of this combination.

Shear bond strength of calcium silicate-based cements to glass ionomers

BackgroundA shear bond strength between the biomaterial and restorative material is crucial for minimizing bacterial microleakage and ensuring a favorable long-term prognosis for vital pulp therapy. This study aimed to conduct a comparative evaluation of the shear bond strength between calcium silicate-based biomaterials utilized in vital pulp treatment and various glass ionomer cement materials, both with and without the application of adhesive agents.MethodsA total of 270 acrylic blocks, each featuring cavities measuring 4 mm in diameter and 2 mm in depth, were prepared. Calcium silicate-containing biomaterials (ProRoot MTA, Medcem Pure Portland Cement, and Medcem MTA), following manufacturers’ instructions, were placed within the voids in the acrylic blocks and allowed to set for the recommended durations. The biomaterial samples were randomly categorized into three groups based on the restorative material to be applied: conventional glass ionomer cement, resin-modified glass ionomer cement, and bioactive restorative material. Using cylindrical molds with a diameter of 3.2 mm and a height of 3 mm, restorative materials were applied to the biomaterials in two different methods, contingent on whether adhesive was administered. After all samples were incubated in an oven at 37 °C for 24 h, shear bond strength values were measured utilizing a universal testing device. The obtained data were statistically evaluated using ANOVA and post-hoc Tukey tests.ResultsThe highest shear bond strength value was noted in the Medcem MTA + ACTIVA bioactive restorative material group with adhesive application, while the lowest shear bond strength value was observed in the ProRoot MTA White + Equia Forte HT Fil group without adhesive application (P < 0.05).ConclusionActiva Bioactive Restorative may be considered a suitable restorative material in combination with calcium silicate-based biomaterials for vital pulp treatment. The application of adhesives to calcium silicate-based biomaterials can effectively address the technical limitations.

Enhancing the durability and antibacterial activity of glass ionomer restorative material enriched by l-arginine and nano-titanium for pit and fissure sealing

BackgroundSealing teeth’ pits and fissures is of prime importance in preventing caries. Despite the evidenced bioactivity of glass-ionomer cements (GICs), they still fail to totally inhibit caries. This partially might be due to their insufficient antibacterial and strength properties. l-arginine (Arg) has superior caries-preventive potential thanks to its prebiotic-based biofilm-modulating effect. Titanium dioxide (TiO2) on the other hand, has well-known antibacterial characteristics, and being in nano size is supposed to improve strength. Therefore, this study aims to improve the antibacterial efficiency and the mechanical properties of conventional GICs using 1% Arg and 3% TiO2 nanoparticles for pit and fissure sealing.MethodsEtched enamel surfaces of 100 extracted human third molars were randomly divided into two groups; a control group, where teeth were restored using glass ionomer Ionofil Plus, and an experiment group, where teeth were restored using glass ionomer Ionofil Plus incorporating Arg–TiO2. Specimens of both groups were tested for microleakage, enamel shear bond strength, and fluoride ion release using a stereo microscope, universal testing machine, and ion chromatography ICs 5000+ SP respectively. Surface analysis was conducted through scanning electron microscopy coupled with energy-dispersive X-ray analysis (SEM–EDX) and atomic force microscope (AFM). Furthermore, specimens of both groups were incubated with Streptococcus mutans, Lacticaseibacillus rhamnosus, and Actinomyces viscous for quantitative antibacterial evaluation, compared to a specimen-free control using adherent/planktonic bacterial count test.ResultsThe experimental group had statistically lower microleakage percentage, higher shear bond strength, and constant fluoride release compared to the control group at P = 0.01, 0.002, and < 0.001 respectively. SEM of the experimental group revealed hybrid particles of the Arg–TiO2 incorporating GIC with clusters of uniformly distributed TiO2 nanoparticles. AFM showed lower surface roughness for the experimental group indicating its homogeneity. The adherent probiotic L. rhamnosus bacterial count had the highest count in Arg–TiO2 (IP) GIC group (P < 0.001) with lack of adherent pathogenic S. mutans bacterial count compared to planktonic/adherent S. mutans bacterial count in the control group and (IP) GIC group (P < 0.05).ConclusionsIncorporating 3% TiO2 nanoparticles and 1% Arg in GICs can enhance their mechanical properties, fluoride release, and antimicrobial efficiency.

Shear Bond Strength of Chemical and Light Cured Glass Ionomer Cements Bonded to Resin Composite

The purpose of this study was to compare the shear bond strength of chemically cured (Conventional) glass ionomer cement and light cured (Resin modified) glass ionomer cement to resin composite and to evaluate the effect of acid etching of the glass ionomer cements on the shear bond strength.Forty acrylic molds were prepared, a hole (6×2) mm was prepared in each mold to retain the glass ionomer cements (GICs). The samples were divided into two main groups. The first group were filled with Conventional GIC and the second group were filled with Resin modified glass ionomer cement (RMGIC), then each group were subdivided into two subgroups, the first subgroup were acid etched and the second subgroup were left without etching. The bonding agent applied to the demarcated bond area on the GIC surface, the composite resin cylinders were built up over the GIC base. The samples were stored for one week in deionized water then thermocycled. The samples then tested for shear bond strength (SBS) using universal testing machine.The result shows that Independent samples T-test used for statistical analysis. The result showed that RMGIC significantly had higher SBS than conventional GIC. No statistical difference was shown in SBS between subgroup etched and without etching for RMGIC, but the conventional GIC showed significantly higher SBS in subgroup without etching than with etching.This study Conclude that the SBS of RMGIC to resin composite was significantly higher than that of conventional GIC. Acid etching the GIC surface did not improve the SBS of GICs to resin composite.

Compressive Strength and Surface Roughness of Nanoparticles Enriched Glass Ionomer Cement

Aim: This study was assumed to investigate the effect of incorporation of nanoparticles “Titanium Dioxide Nanoparticles (TiO2)” in two different percentages which are 3% and 5% (by weight) on compressive strength and surface roughness of glass ionomer cement (GIC) so to improve the conventional glass ionomer cement properties.Materials and Methods: the powder of GIC was incorporated with TiO2 nanoparticles at two concentrations: 3% and 5% (w/w). An unmodified conventional GIC used as the control group. Ten specimens of each GIC group were used to study the compressive strength using a Universal Testing Machine. Also, 10 discs from each GIC group were used for surface roughness measurement by using profilometer. one way analysis of variance ANOVA test and Tukey’s test were used to analyze data. Results: Nanoparticles incorporation to GIC lead to improve its compressive strength for both percentages 3% and 5%, Tukey’s test showed a significant increase in compressive strength between nanoparticles incorporated and conventional group. The surface roughness measurement also show significantly improvement in both 3% and 5% nanoparticles groups (p&lt;0.05). Conclusion: GIC with TiO2 nanoparticles.

The effect of the static magnetic field on some of the mechanical properties of glass ionomer cements

Objective. The objective of this study was to investigate the impact of storing two distinct types of glass ionomer cement (GIC) in a static magnetic field (SMF) on their mechanical characteristics, namely compressive strength, microhardness and degree of conversion. Methods. In the current investigation, 10 samples of each GIC type were utilized for each test. The entire tube of the resin modified type was preserved in a (SMF) for a duration of 48 hours, whereas just the powder of the conventional type was retained in SMF for the same time period. The SMF was calibrated to a value of 225 Gauss. Special identical molds were prepared for each test. All the tests were performed after 24 incubation period at 37 degrees in deionized water. The final data were analyzed using Wilcoxon Rank test (p ≤0.05). Results. The compressive strength of the conventional type and resin modified type that used in this study were significantly increased after exposed to the SMF from 195.33 (29.6) to 209.286 (11.78) 317.29 (55.4) to 523.38 (13.07) MPa respectively. The degree of conversion was also improved significantly after exposed to SMF, as the conventional type increased from 37.03 to 45.00, while the resin modified type from 42.2 to 59.3, the conventional type improved significantly for microhardness test but the resin modified type improved non-significantly. Conclusion. Storing the GIC in a 225 gauss SMF enhances the mechanical characteristics and the degree of conversion of resin modified and conventional GIC.

In Vitro Investigation of Shear Bond Strength of Titanium Alloy Bonded to Monolithic Zirconia Prepared Via Different Surface Roughening Methods Using Different Cements

Objective: To evaluate the shear bond strength (SBS) of yttrium-stabilized tetragonal zirconia polycrystals bonded to titanium alloys via different surface treatment methods using four different cements.&#x0D; Methods: Eighty titanium and monolithic zirconia discs were prepared with computer-aided design/manufacturing (CAD/CAM) technology. All titanium discs and 40 of monolithic zirconia discs were polished by using silicon carbide paper and sandblasted with 50 μm aluminum oxide (Al2O3). Tribochemical silica coating was applied to remaining 40 monolithic zirconia discs. The monolithic zirconia discs were divided into eight groups after surface treatment (n=10). Titanium discs were cemented using conventional glass ionomer cement (GIC), resin-modified GIC, self- adhesive resin cement, and dual-cure resin cement. The SBS test was performed using a universal testing machine. The failure patterns were examined by using a scanning electron microscope (SEM). Data were statistically analyzed with one-way analysis of variance (ANOVA), two-way ANOVA and Tukey’s test (α

Effect of ethanolic extract of propolis on antibacterial and microshear bond strength of glass-ionomer restorations to dentin

ObjectivesThis study was conducted to evaluate the effect of ethanolic extract of propolis on antibacterial and microshear bond strength of glass ionomer restorations to dentin. Materials and methodsConventional glass ionomer cement (Equia forte, GC Tokyo, Japan), resin-modified glass ionomer (Fuji II LC, GC Tokyo, Japan) and propolis powder (dried extract from honey bees) materials were used in this study. Both conventional glass ionomer and resin-modified glass ionomer were modified by two different concentrations of ethanolic extract of propolis (10 % and 25 % EEP). For antibacterial test, Streptococcus mutans strain was spread on agar petri dishes using a sterile swab. Discs of both glass ionomer restorative materials (without adding EEP, with 10 % EEP and with 25 % EEP) were fabricated within the agar plates. Antibacterial activity was evaluated by measuring the inhibition zones around each disc. For microshear bond strength test, 60 healthy human permanent molars were prepared by cutting occlusal surface and expose the dentin at the height of contour of all teeth then conditioned using poly acrylic acid conditioner, both glass ionomer restorative materials (without adding EEP, with 10 % EEP and with 25 % EEP) were mixed and applied on conditioned dentin surface by using tygon tube. Microshear bond strength was evaluated by the universal testing machine. ResultsTwo-way ANOVA test revealed that both glass ionomer type and different concentrations of EEP had significant effect on the antibacterial test results and microshear bond strength values (p < 0,05). Glass ionomer restorative material with 25%EEP had the highest antibacterial values whereas glass ionomer restorative material without modifications (control groups) had the lowest values. Resin-modified glass ionomer without any modification (control group) had the highest bond strength while resin-modified glass ionomer with 25%EEP had the lowest bond strength. ConclusionsIncorporation of ethanolic extract of propolis to glass ionomer restorative material increases the antibacterial effects of both conventional GIC and RMGI. Inspite of this advantage, it seems that it has deleterious effect on microshear bond strength to dentin.

Effects of Incorporation of Titanium Dioxide Nanoparticles on Mechanical Properties of Conventional Glass Ionomer Cement

Background: Due to the poor mechanical properties of Glass Ionomer Cement (GICs), their use is limited to low stress-bearing areas. This study aimed to assess the effect of the addition of Titanium Dioxide (TiO2) nanoparticles on the flexural strength and surface hardness of GIC.&#x0D; Methods: In this in vitro study, 3, 5, and 10 wt.% TiO2 nanoparticles were added to Fuji II conventional GIC powder. The purity and composition of the as-synthesized titania were investigated by using XRD and FT-IR tools. The homogeneity of powder particles within the used matrix was evaluated under a Scanning Electron Microscope (SEM).&#x0D; Results: The SEM micrographs confirmed the homogenous mixing of TiO2 nanoparticles with GIC powder.&#x0D; Conclusion: Nevertheless, the flexural strength of experimental groups was not significantly different from that of the control group (p=0.384). However, the surface hardness of experimental groups was decreased in comparison with that of the control group (p&lt;0.001).

Systematic review and network meta-analysis of restorative therapy and adhesive strategies in root caries lesions

AimThis systematic review and network meta-analysis (NMA) aimed to establish a clinically relevant hierarchy of the different adhesive and/or restorative approaches to restore cavitated root caries lesions through the synthesis of available evidence. Materials and methodsA systematic search was conducted in Medline/Web of Science/Embase/ Cochrane Library/Scopus/grey literature. RCTs investigating ≥2 restorative strategies (restorative /adhesive materials) for root caries lesions in adult patients were included. Risk of bias within studies was assessed (Cochrane_RoB-2) and the primary outcome was survival rate of restorations at different follow-up times (6-/12-/24-months). Network meta-analyses were conducted using a random effects model stratified by follow-up times. I2-statistics assessed the ratio of true to total variance in the observed effects. All available combinations of adhesives (1-SE: one-step self-etch; 2–3ER: two-/three-step etch-and-rinse) and restorative materials (conventional composite (CC) as well as conventional and resin-modified glass ionomer cements (GIC, RMGIC)) were included. Risk of bias across studies and confidence in NMA (CINeMA) were assessed. Results547 studies were identified and nine were eligible for the NMA. In total, 1263 root caries lesions have been restored in 473 patients in the included clinical trials. Patients involved were either healthy (n = 6 trials), living in nursing homes (n = 1 trial) or received head-and-neck radiotherapy (n = 2 trials). There was statistically weak evidence to favour either of material/material combination regarding the survival rate. A tendency for higher survival rate (24-months) was observed for 2–3ER/CC (OR24mths 2.65; 95%CI=1.45/4.84) as well as RMGIC (OR24mths 2.05; 95%CI=1.17/3.61) compared to GIC. These findings were though not statistically significant and confidence of the NMA was low. ConclusionAn evidence-based choice of restorative strategy for managing cavitated root caries lesions is currently impossible. There is a clear need for more standardised, well-designed RCTs evaluating the retention rate of root caries restoration approaches.

Depth of Porosity of Glass Ionomer Cement with the Addition of Nano-Sized Gourami Scale Powder

Background: Glass ionomer cement (GIC) contains higher porosity than other restorative materials. Porosity can cause the GIC surface to become rough and reduce the material's mechanical properties. Gourami fish scales powder (GFSP) contains hydroxyapatite, which can potentially reduce the porosity of GIC. This research aimed to analyze the porosity depth of conventional GIC by adding 1.5%, 2.5%, and 3.5% GFSP nanoparticles (nGFSP). Materials and Methods: This type of research is an experimental laboratory with a post-test-only control group design. Twelve samples were disc-shaped diameter of 5 mm and a height of 2 mm which were divided into four groups: G0:GIC, G1: GIC+1,5% nGFSP, G2: GIC +2,5% nGFSP, and G3: GIC+3,5% nGFSP). Samples were cut into two parts and observed by Scanning Electron Microscopy (SEM). The results were analyzed by One Way ANOVA and Least Significant Difference (α = 0,05). Result: The average value of the porosity depth from the highest to the lowest is G0, G1, G2, G3. There was a significant difference between all sample groups (p = 0.000). Conclusion: The addition of nanoparticles GFSP reduced the porosity depth of conventional GIC; the addition of 3.5% nanoparticles GFSP showed the shallowest porosity depth.