Zirconia-reinforced Glass Ionomer Research Articles

In-vitro Study Comparing the Shear Bond Values of Zirconia-reinforced Glass Ionomer Cement and Conventional Glass Ionomer Cement

The goal of the current study was to compare the shear bond values of zirconia-reinforced glass ionomer cement and conventional glass ionomer cement. A collection of 20 extracted premolars with unbroken buccal or lingual surfaces was made. The whole sample was randomly split into two groups: Group A (n=10) which was Conventional Glass Ionomer Cement and Group B (n=10) which was Zirconia Reinforced Glass Ionomer Cement (Zirconomer). The process of thermocycling was used to mimic oral conditions. Using a universal testing machine, the shear bond strength (SBS) was measured after 24 hours at a crosshead speed of 0.5 mm/minute until fracture. After tabulating the results, statistical analysis was done. The findings indicated that Zirconomer exhibited a statistically significant (p ≤ 0.05) higher shear bond strength when compared to traditional glass ionomer cement.

Effect of the Different Dietary Supplements on the Average Surface Roughness and Color Stability of Direct Restorative Materials Used in Pediatric Dentistry.

Increased surface roughness and discoloration of the direct restorative materials used in pediatric patients affect the longevity of restorations and impair children's oral health. Many factors can alter these properties. One of these factors is the intake of dietary supplements. It is crucial to predict the properties of restorative materials when exposed to dietary supplements to maintain the dental care of children. Thus, this study aimed to investigate the effect of various syrup-formed dietary supplements on the average surface roughness and color stability of current restorative materials used in pediatric dentistry. Seven different restorative materials (conventional glass ionomer [Fuji IX GP], resin-modified glass ionomer, [Fuji II LC], zirconia-reinforced glass ionomer [Zirconomer Improved], polyacid-modified composite resin [Dyract®XTRA], bulk-fill glass hybrid restorative [Equia Forte HT Fill], conventional resin composite [Charisma Smart], and resin composite with reactive glass fillers [Cention N]) were tested. The specimens prepared from each type of restorative material were divided into five subgroups according to dietary supplements (Sambucol Kids, Resverol, Imunol, Umca, and Microfer). These specimens were immersed daily in supplement solution over a period of 28 days. Surface roughness and color difference measurements were performed at baseline and at the 7th and 28th days. The color difference and Ra values showed that there was an interaction among the type of restorative material, type of dietary supplement, and immersion time factors (p < 0.05). Whereas lower Ra values were found in the composite resin group, the highest Ra values were found in the conventional glass ionomer group. All supplements caused increasing color difference values, and Resverol and Umca showed higher discoloration values above the clinically acceptable threshold. The intake of dietary supplement type, the immersion time of the dietary supplement, and the restorative material type affected the surface roughness and color stability of the tested direct restorative materials. All of the experimental groups showed higher Ra values than clinically acceptable surface roughness values (0.2 µm). The color difference values also increased with the immersion time.

Clinical Performance of Zirconia Reinforced versus Conventional Viscous Glass Ionomer in Class I Cavities of Geriatric Patients: A 1-year Randomized Controlled Clinical Trial.

For the elderly population, efforts are made to simplify the restorative procedure while maintaining good clinical performance. Glass ionomer (GI) cements are showing signs to fulfill many of these qualities. With their new properties and ease of use, they can be developed further to become a useful group of materials to overcome the problems of elderly patients. The aim of the study was to evaluate the clinical performance of zirconia-reinforced versus conventional viscous GI restorations in Class I cavities of geriatric patients. The study design was in vivo randomized clinical trial, parallel-arms, allocation ratio: 1:1. A total of 28 Class I carious lesions in 21 geriatric patients were restored randomly either by zirconomer-improved or Ketac Molar Quick Aplicap (n = 14) each. Restorations were evaluated for 1 year by modified USPHS criteria. Data were analyzed with the Chi-square test and Cochran's Q-test. Survival rate was analyzed using the Kaplan-Meier and log-rank test. Twenty-four restorations were evaluated in 19 patients with a recall rate of 85.7% at 12 months. Significant differences were found in marginal integrity and marginal discoloration within both restorative materials between different time intervals (P < 0.05). However, none of the materials were superior to another regarding all assessed criteria. Both zirconia-reinforced GI and conventional highly viscous GI have acceptable clinical performance.

Clinical Performance and Wear Resistance of Highly Translucent Nano Zirconia Reinforced Glass Ionomer Filling Versus Conventional Resin Composite Restorations in Patients with Proximal Carious Teeth: Randomized Clinical Trial

Aim: This study aimed to evaluate the clinical performance and occlusal wear resistance of nano- zirconia reinforced glass ionomer restorations in comparison to nano-hybrid resin composite restorations in proximal cavities. Material and Method: This randomized clinical trial was conducted on thirty-two patients who had proximal carious lesions in posterior teeth. Participants were randomly allocated into two groups (n=16 for each group) in which they received either; Nano zirconia reinforced glass ionomer restorations (Zirconomer Improved, Shofu, Japan) or Conventional nano hybrid resin composite (Filtek Z250 XT, 3M ESPE, USA), all materials were applied according to manufacturers’ instructions. Restorations were evaluated at baseline (immediately), after six months, and after 12 months by two blinded assessors using modified USPHS criteria measuring (postoperative hypersensitivity, secondary caries, gross fracture, color match, cavo-surface marginal discoloration, marginal integrity, proximal contact and wear resistance). Data was analyzed using Medcalc software, intergroup comparisons between interventions was performed using the Chi-Squared test with statistical significance level set at (P ≤ 0.05) while intragroup at (P ≤ 0.016) after Bonferroni correction, relative risk was used to assess the clinical significance. Results: Intergroup comparison between both materials regarding USPHS criteria and wear resistance have shown no statistically significant difference within different follow up periods; baseline, 6 and 12 months respectively except for the color match shown significant difference with highly translucent nano zirconia reinforced GI. Intragroup comparison within highly translucent nano zirconia reinforced glass ionomer and within conventional resin composite regarding USPHS criteria have shown no statistically significant difference between different followup periods except for the wear resistance shown significant difference within highly translucent nano zirconia reinforced GI. Conclusion: Nano zirconia reinforced glass ionomer and Nano hybrid resin composite have a similar clinical performance and wear resistance after one year follow up.

Comparative Evaluation of Fracture Toughness and Flexural Strength of Four Different Core Build-up Materials: An In Vitro Study.

To evaluate and compare the fracture toughness and flexural strength of four different core build-up materials. A total of 60 samples were divided into four groups (n = 15) group I: dual cure composite resin reinforced with zirconia particles (Luxacore Z), group II: light cure composite resin (Lumiglass DeepCure), group III: zirconia reinforced glass ionomer cement (GIC) (Zirconomer Improved), and group IV: chemically cure composite resin (Self Comp) respectively. All the core build-up materials were manipulated according to the manufacturer's instructions and poured into the mold. A universal testing machine applied a central load to the specimen in a 3-point bending mode. Fracture of the specimen was identified and the reading was recorded by the universal testing machine. The data were analyzed statistically using one-way analysis of variance (ANOVA) and then compared. Group I showed the highest flexural strength (48.65 MPa) among all the groups while group IV showed the lowest flexural strength (17.90 MPa). Group I showed the highest fracture toughness (99.12 MPa) among all the groups while group IV showed the lowest fracture toughness (36.41 MPa.cm-0.5). When mean flexural strength and fracture toughness values of all four groups were compared by using one-way ANOVA, the compared data was highly significant. Based on the findings of this study, dual cure composite resin was the material of choice in terms of flexural strength and fracture toughness for core build-up material followed by light cure composite resin. The core buildup material serves to strengthen the tooth structure, allowing it to withstand the forces of chewing and preventing the risk of tooth fractures. This material is essential in restoring damaged or decayed teeth, as it provides a stable foundation for further dental work. By reinforcing the tooth structure, the core buildup material ensures that the tooth can function properly and remain healthy for years to come. How to cite this article: Nakade P, Thaore S, Bangar B, et al. Comparative Evaluation of Fracture Toughness and Flexural Strength of Four Different Core Build-up Materials: An In Vitro Study. J Contemp Dent Pract 2024;25(2):191-195.

A Comprehensive Evaluation of Zirconia-Reinforced Glass Ionomer Cement's Effectiveness in Dental Caries: A Systematic Review and Network Meta-Analysis.

Dental cements are in a constant state of evolution, adapting to better align with the intricacies of tooth structure and the dynamic movements within the oral cavity. This study aims to evaluate the efficacy of zirconia-reinforced glass ionomer cement-an innovative variant of modified glass ionomer cements-in terms of its ability to withstand compressive forces and prevent microleakage during dental caries reconstruction. An extensive search was conducted across various databases, encompassing PubMed-MEDLINE, Scopus, Embase, Google Scholar, prominent journals, unpublished studies, conference proceedings, and cross-referenced sources. The selected studies underwent meticulous scrutiny according to predetermined criteria, followed by the assessment of quality and the determination of evidence levels. In total, 16 studies were incorporated into this systematic review and network meta-analysis (NMA). The findings suggest that both compomer and giomer cements exhibit greater compressive strength and reduced microleakage values than zirconia-reinforced glass ionomer cement. In contrast, resin-modified glass ionomer cement (RMGIC) and high-viscosity glass ionomer cement (GIC) demonstrate less favorable performance in these regards when compared with zirconia-reinforced glass ionomer cement.

The Effect of 1% Povidone Iodine Mouthwash on The Surface Roughness of Zirconia Reinforced Glass Ionomer Cement

&#x0D; Introduction: Zirconia reinforced glass ionomer cement is a new generation glass ionomer cement restoration material with the addition of zirconia nanoparticles that is equivalent in strength to amalgam while maintaining ability to release fluoride like conventional glass ionomer cements. Surface roughness can be affected by various factors including the use of mouthwash. Mouthwash that is commonly used during pandemic COVID-19 is 1% povidone iodine. Previous study stated that povidone iodine mouthwash contains alcohol and acidic pH which can decrease the hardness of composite resins. Objective: To determine the effect of 1% povidone iodine mouthwash on the surface roughness of zirconia reinforced glass ionomer cement. Methods: This was a true experimental laboratory research with a pre test and post test control group design. The research samples consisted of 36 samples of zirconia reinforced glass ionomer cement with diameter of 10 mm and height of 2 mm. The samples were divided into two groups: the control group which was immersed in artificial saliva and the treatment group which was immersed in 1% povidone iodine mouthwash for 24 hours. Surface roughness was measured using a surface roughness tester. Data were analyzed using Paired Sample T-Test and Independent Sample T-Test. Results: Paired Sample T-test results showed no significant difference in the surface roughness of the control group between before and after immersion with p value = 0,074 (p&gt;0,05) and a significant difference in the surface roughness of the treatment group between before and after immersion with p value = 0,000 (p&lt;0,05). Independent Sample T-Test results showed significant difference in the surface roughness between the control group and the treatment group with p value = 0,000 (p &lt;0.05). Conclusion: 1% povidone iodine mouthwash has an effect on increasing the surface roughness of zirconia reinforced glass ionomer cement.

Clinical comparison of different glass ionomer-based restoratives and a bulk-fill resin composite in Class I cavities: A 48-month randomized split-mouth controlled trial

ObjectiveThe aim of this study is to compare the retention rates (primary outcome) of high-viscosity glass ionomer (GI), glass carbomer (GC), zirconia-reinforced GI (ZIR), and bulk-fill (BF) composite resin restorations. Secondary outcomes included anatomical form, marginal adaptation, marginal discoloration, color match, surface texture, post-operative sensitivity and secondary caries. MethodsTwo calibrated operators placed 128 restorations in 30 patients with a mean age of 21 years. The restorations were evaluated by one examiner at baseline and at 6, 12, 18, 24, and 48 months using the modified US Public Health Service criteria. The data were statistically analyzed using Friedman test. Differences between restorations were analyzed using Kruskal–Wallis test. ResultsAfter 48 months, 23 patients and 97 restorations (23 GI, 25 GC, 24 ZIR, and 25 BF) were evaluated. Patient recall rate was 77%. No significant difference was observed between the retention rates of the restorations (p > 0.05). GC showed significantly lower results than the other three fillings in terms of anatomical form (p < 0.05). There was no significant difference in the anatomical form and retention between GI, ZIR, and BF (p > 0.05). No significant change was observed in the postoperative sensitivity or secondary caries for any of the restorations (p > 0.05). ConclusionsGC restorations showed statistically lower anatomical form values, indicating lower wear resistance than the other materials. However, no significant difference was observed in the retention rates (as primary outcome) as well as the other secondary outcomes of the four different restorative materials after 48 months. Clinical SignificanceGI-based restorative materials and BF composite resin restorations in Class I cavities yielded satisfactory clinical performance after 48 months.

Evaluation of the Masking Effect of Different Glass Ionomer Restorations following Silver Diamine fluoride and Potassium Iodide Application: An In Vitro Study

Abstract Objectives This is an in vitro study that aimed to evaluate the ability of different glass ionomer restorations to mask the discoloration produced following silver diamine fluoride (SDF) only and after potassium iodide (KI) application. Materials and Methods Thirty-six extracted human adult posterior teeth were collected. Box-shaped cavities (4 × 2 × 2 mm3) were prepared along the cementoenamel junction. Specimens were randomly divided into two major groups according to the materials applied under the restorations group (A) 38% silver diamine fluoride (SDF) followed by immediate application of potassium iodide (KI), group (B) 38% silver diamine fluoride (SDF) only. Each group was further subdivided according to the restorative material applied as follows (n = 6): subgroup (I) zirconia reinforced glass ionomer, subgroup (II) resin-modified glass ionomer restoration, and subgroup (III) high viscous glass ionomer restoration. Color assessment of all specimens was performed using a reflective spectrophotometer. Specimens' color was assessed color of normal dentin then assessed immediately after application of SDF (group A) and after application SDF + KI (group B) with the respective restorative material used. Statistical Analysis Data showed parametric distribution and variance homogeneity and were analyzed using one-way analysis of variance followed by Tukey's post hoc test. Results Intergroup comparisons showed that for SDF and SDF + KI samples, there was a significant difference between the different restorative materials (p &lt; 0.001). For glass ionomer, SDF samples had significantly higher color change value than SDF + KI (p &lt; 0.001), while for RMGI and zirconia reinforced glass ionomer, SDF + KI samples had significantly higher value (p &lt; 0.001) although zirconia reinforced glass ionomer showed the least color change following SDF (6.00 ± 2.74). Conclusion Within the limitations of this study, we could conclude that using zirconia reinforced glass ionomer could have a good masking effect on discoloration produced by SDF. While the resin-modified glass ionomer restoration showed more discoloration and darkening effect even after using of KI. Also, using KI in combination with SDF had a good masking effect on discoloration that produced by SDF.

Assessment of Biological Properties of Zirconia Reinforced Glass Ionomer versus Glass Ionomer with Glass Hybrid Technology in Class II Cavities. Randomized Controlled Clinical Trial

Assessment of Biological Properties of Zirconia Reinforced Glass Ionomer versus Glass Ionomer with Glass Hybrid Technology in Class II Cavities. Randomized Controlled Clinical Trial

Assessment of Functional Properties of Zirconia Reinforced Glass Ionomer versus Glass Ionomer with Glass Hybrid Technology in Class II Cavities. Randomized Controlled Clinical Trial

Assessment of Functional Properties of Zirconia Reinforced Glass Ionomer versus Glass Ionomer with Glass Hybrid Technology in Class II Cavities. Randomized Controlled Clinical Trial

Comparative Evaluation of Water Sorption, Solubility, and Microhardness of Zirconia-reinforced Glass Ionomer, Resin-modified Glass Ionomer, and Type IX Glass Ionomer Restorative Materials: An In Vitro Study.

The study aimed to evaluate and compare water sorption, solubility, and microhardness of zirconia-reinforced glass ionomer, resin-modified glass ionomer, type IX glass ionomer cements. 90 specimens were prepared in total of which 45 cylindrical specimens with dimensions of (6 × 4) mm and 45 disks with (10 × 2) mm were prepared from Zirconomer, RMGIC, and Type IX GIC restorative materials, each material having 30 specimens (15 disks, 15 cylinders). After taking the initial weight (W1), the 45 cylinders (15 of each material) were immersed in artificial saliva at 37°C for 28 days after which the weights W2 and W3 were weighed. The other 45 disks (15 of each material) were subjected to microhardness test under microhardness tester. Results were subjected to ANOVA and Tuckey's post hoc test. Zirconomer showed the maximum resistance to water sorption and solubility followed by RMGIC and type IX GIC with a significant p value of < 0.001 difference. For microhardness, Zirconomer showed the highest value with a significant p value of < 0.001 difference. But, there was no significant difference between RMGIC and Type IX GIC depicting almost equal strength. Water sorption, solubility, and microhardness of Zirconomer were significantly high in comparison to the other groups and it can be used as a posterior restorative material for stress-bearing areas. As pediatric dentistry demands restorations to be completed frequently in less than ideal conditions, Zirconomer has shown to be better than RMGIC and conventional GIC probably because of the improvisation in the GIC properties. Bethapudy DR, Bhat C, Lakade L, et al. Comparative Evaluation of Water Sorption, Solubility, and Microhardness of Zirconia-reinforced Glass Ionomer, Resin-modified Glass Ionomer, and Type IX Glass Ionomer Restorative Materials: An In Vitro Study. Int J Clin Pediatr Dent 2022;15(2):175-181.

Comparative evaluation of compressive strength and fracture resistance of posterior restorative materials alkasite and newer glass ionomers with amalgam: An in vitro study

Aim: The conventional restorative materials amalgam and glass ionomer have multifarious drawbacks leading to introduction of newer materials with superior biomechanical attributes. The present study aimed to assess and compare the compressive strength of ceramic-reinforced glass ionomer cement, zirconia-reinforced glass ionomer cement, high strength glass ionomer posterior restorative material, alkasite restorative material, and amalgam when used as posterior restorative materials. Materials and Methods: Five restorative materials were evaluated: modified glass ionomer cements including ceramic-reinforced, zirconia-reinforced, and high strength glass ionomer; alkasite restorative material; and dental amalgam. Fifty cylindrical specimens were fabricated using test materials (n = 10 for each group). Class II cavities prepared on 50 intact permanent molars were restored with test materials. After thermocycling and 24 h of storing, the specimens in artificial saliva, compressive strength, and fracture resistance were tested. Data were analyzed statistically. One-way analysis of variance and post hoc Tukey test were used for intergroup comparison. Pearson’s correlation was used for correlating the maximum load by cylindrical and tooth specimens. Results: A significantly high compressive strength was displayed by specimens of group 4, followed by group 5, group 3, group 1, and least by group 2. The highest fracture resistance was displayed by teeth restored with the test materials in group 4, group 1, group 5, group 2, and least by group 3. Conclusion: Within the limitations of the present study, alkasite restorative material (Cention N) showed the highest compressive strength in cylindrical and highest fracture resistance in tooth specimens.

Evaluating fluoride uptake of dentin from different restorative materials at various time intervals – In vitro study

BackgroundGlass ionomer cement is very popular in clinical practice due to their antibacterial and cariostatic properties, which is totally dependant on the amount of fluoride release and uptake by dentine. The short-term and long-term fluoride uptake by dentine from commercially available restorative materials like nano-ionomer, zirconia reinforced glass ionomer cement and flowable composite is of clinical interest. ObjectiveTo evaluate and compare Nano-ionomer, Zirconia reinforced glass ionomer, and flowable composite resin for the fluoride uptake by dentin at different time intervals. ResultsOne–way ANOVA (Tukey-Kramer Multiple Comparison Test) was applied to test the comparison of mean values of all parameters compared together. The student's paired ‘t’ test was applied to compare groups. The fluoride uptake was evaluated at 3 days and 42 days. At 3 days dentin showed higher fluoride uptake with Zirconomer (Group Z) as compared to Ketac N100 and SDR Composite which was statistically significant. At 42 days higher fluoride uptake was seen in Ketac N100 (Group K) as compared to Zirconomer and SDR composite which was also statistically significant. ConclusionFluoride uptake by dentine was seen in all study materials. Fluoride uptake by dentine at 3 days was seen maximum in Zirconomer, whereas fluoride uptake at 42 days was more in Ketac N100.

Comparative Evaluation of Shear Bond Strength of Bioactive Restorative Material, Zirconia Reinforced Glass Ionomer Cement and Conventional Glass Ionomer Cement to the Dentinal Surface of Primary Molars: an in vitro Study.

Statement of the Problem: The success of dental restorations depends mainly on its ability to bond to dental structures and resist the multitude of forces acting on it within the oral cavity.Purpose: Therefore, the aim of this study was to evaluate the shear bond strength (SBS) of three different glass ionomer based restorative materials.Materials and Method: In this in vitro analytical study, 30 intact primary molars were sectioned buccolingually to obtain 60 sections. These sections were embedded in auto polymerizing acrylic resin and polished to obtain a flat dentin surface. Restoration cylinders were built on the dentin surface with the help of a Teflon template called bonding jig. Each group (n= 20) was restored as group A with conventional glass ionomer cement (GIC) (GC Fuji Gold Label Type 9), group B with Bioactive restorative material (ACTIVATM KIDS BioACTIVE Restorative material), and group C with Zirconia reinforced glass ionomer cement (Zirconomer). Following restoration, SBS testing was performed using Universal Testing Machine. The data obtained were statistically analyzed using One way ANOVA test and post hoc Tukey test (p= 0.05).Results: The SBS values were significantly greater in the ACTIVA KIDS group as compared to the other two groups (p< 0.05). There was no significant difference in the SBS values between group B and group C (p> 0.05).Conclusion: The SBS of the ACTIVA KIDS to primary teeth dentin was the highest as compared to Zirconomer and conventional GIC. Therefore ACTIVA KIDS may protect primary teeth against recurrent caries and failure of the restoration.

PROPERTIES OF COMPOSITE RESIN ALKASIT AND ZIRCONIA-REINFORCED GLASS-IONOMER CEMENT IN DIFFERENT STORAGE

Background: The temperature and salivary pH in a person's mouth are highly dynamic (e.g., before, during, and after eating) and so restorations in a cavity must be resilient to these variable conditions. Temperature and immersion conditions affect the mechanical properties of a restoration. This study aimed to determine the effect of environmental conditions on diametral tensile strength (DTS) and surface microhardness of a resin composite with alkaline fillers or zirconia–reinforced glass ionomer cement (Zr-reinforced GIC). Method: Thirty specimens of a resin composite with alkaline fillers (Cention-N, Ivoclar-Vivadent, Lichtenstein) and 30 specimens with zirconia-reinforced GIC (Zirconomer, Shofu, Japan) were stored at different conditions (23°C and 37°C; with and without immersion in water) for 24 hours. DTS was tested with a Universal Testing Machine (AGS-X series, Shimadzu, Japan) and surface microhardness was tested with a Vickers Microhardness tester (HMV-G Series Micro Vickers Microhardness Tester, Shimadzu, Japan). Data were analyzed statistically using a one-way ANOVA test (and Shapiro-Wilk test. Result: The values of microhardness and DTS increased significantly both for the composite resin alkasite and zirconia-reinforced GIC with increasing temperature in the groups without immersion. However, there was a significant decrease in microhardness and DTS after immersion in distilled water at 37°C for both the composite resin alkasite and zirconia-reinforced GIC. Conclusion: It can be concluded that storage conditions affect the microhardness and DTS of resin composite Alkasite and Zirconia-reinforced GIC

A COMPARATIVE EVALUATION OF MICROLEAKAGE, COMPRESSIVE STRENGTH, FLEXURAL STRENGTH AND FLUORIDE RELEASE OF ZIRCONOMER AND KETAC SILVER: AN IN VITRO STUDY.

Background: A successful restorative material forms a better adhesion, resist the microleakage and releases fluoride. However, existing glass ionomer cements cannot be used as a posterior restorative material in stress bearing areas. A new ionomer called Zirconomer, zirconia reinforced glass ionomer claims to exhibit high physical and biological properties.&#x0D; Aim: To assess and compare the microleakage, compressive strength, flexural strength and fluoride release from zirconomer with ketac silver.&#x0D; Materials &amp; Methods: On twenty caries free premolar teeth (10 per each group), a class v cavity was restored with zirconomer and ketac silver. The microleakage was assessed using dye penetration test and stereomicroscope. The compressive and flexural strengths of these materials were measured using Instron Universal testing machine. The amount of fluoride released from the modified ionomers at pH 5 and pH 7 was estimated using Orion fluoride specific electrode. The obtained data was then subjected to statistical analysis.&#x0D; Results: Data was analysed using paired t-test for intergroup comparisons and unpaired t-test for intragroup comparisons. The overall microleakage (0.5±0.48) of zirconomer was significantly less (p=0.000) compared to ketac silver (1.9±0.83). Zirconomer demonstrated a significant higher compressive strength (330.25±60.14), flexural strength (33.058±2.36) than ketac silver (p= 0.000). Zirconomer demonstrated high fluoride release from day 1 to day 7 at both pH 5 and pH 7.&#x0D; Conclusion: Zirconomer demonstrated better physical and biological properties compared with ketac silver.

Assessment of the Fracture Resistance of Novel Zirconia Reinforced Glass Ionomer in Comparison to Nano Hybrid Resin Composite Restorations

Objective: Evaluation of the influence of newly introduced Zirconia reinforced glass ionomer when used as a base or as a restorative material on fracture resistance and fracture pattern of class II restorations.Methodology: Forty extracted, intact mandibular third molars with standardized MO cavities were randomly assigned into four groups according to the type restorative material: The control group was restored using nano hybrid resin composite (RC), Zirconia reinforced restorative glass ionomer group was used for restoring Zr group, resin modified glass ionomer cement as a base material below the resin composite restorations in RC/RMGI group and Zirconia reinforced restorative glass ionomer as a base material below the resin composite restorations in group RC/Zr group. After thermal cycling fracture resistance of the specimens was tested by the application of load in a universal testing machine. Fracture pattern of each specimen was also evaluated. Mean fracture resistance values for each group were calculated and compared using one way ANOVA (P = 0.05). Results: The highest mean load necessary to fracture the specimens was found in RC/RMGI followed by RC/Zr and RC groups respectively. While the lowest mean value was found in Zr group. The highest frequency of specimens’ reparability was found in Zr group followed by RC/Zr and RC groups respectively. While the least frequency of reparability was found in RC/RMGI group.Conclusions: Within the limitations of the current study, it could be concluded that despite higher fracture strength values of RMGIC as a base material below the resin composite restorations, clinicians might prefer using of Zirconomer Improved® as either a restoration or a base material as its fracture patterns are repairable.

Effect of different beverages on microhardness of Zirconia reinforced Glass Ionomer and micro-hybrid Resin composite

Objective: This study aimed to evaluate the influence of commonly used beverages, on surface microhardness of Zirconia reinforced glass ionomer (Zirconomer improved) and microhybrid resin-based composite (Filtek Z250).Materials and methods: A total of 40 disk-shaped specimens were fabricated (20 discs from each type of material). Ten Specimens from each material were immersed in Instant Coffee and the other ten Specimens were immersed in Cola. After initial microhardness recording, each group was subject to thermocycling and then microhardness was re-assessed (n= 10). Results: It was observed that each of restorative material type, thermocycling, and immersion solution, had a statistically significant effect on mean microhardness of both tested materials irrespective of the other tested variables.Conclusion:Resin composite showed significant higher hardness values when compared to Zirconia reinforced glass ionomer. There was a significant decrease in hardness in both materials after thermocycling, with a significant influence of soft drinks more than instant coffee.

It’s not amalgam, it is white amalgam

IntroductionA new class of restorative GIC, named Zirconomer, with increased strength and durability has been developed. It shows strength of amalgam, so it is also called white amalgam. Inclusion of zirconia fillers reinforces the structural integrity of that material, imparts its outstanding posterior esthetics, completely eliminates mercury hazards, and also it is fluoride rich, especially in cases with high caries risk. It is an ideal requirement for restorative material it has a good color stability, a co-efficient of thermal expansion, biocompatibility similar to that of natural tooth, remarkable edge strength, excellent marginal seal, and the ability to adhere chemically to enamel and dentin. Glass ionomer cements are esthetically more pleasing than metallic restorations, on the contrary, their use in dentistry as a restorative material in stress-bearing areas is limited due to poor mechanical properties. New GIC formulations are being introduced every day with improved physical and mechanical properties. ObjectivesZirconomer compared to Amalgam restoration. Materials and methodsArticles found through Medline search; Pubmed, Scopus, Cochrane Library databases covering years starting from 2010 to 2018 were reviewed. Key search words “Zirconomer,” “zirconium oxide,” “non-metal restorations,” “ceramic oxides,” “veneering ceramic,” “zirconia reinforced glass ionomer cement,” “zirconiabased fixed dental prostheses” and silver amalgam were used. Both in-vivo and in-vitro studies into zirconia-based restoration behavior were included. ResultsZirconomer restorations are found to be best alternative now to both GICs with its other modifications as well as dental amalgam for teeth restorations. Some bacterial retention on final could be expected when used. ConclusionsZirconomer and its family restorations are recommended for restorations of deciduous or permanent teeth. Further in-vitro and in-vivo works are needed to confirm their remarkable behavior. Conflict of interestThe authors declared that there is no conflict of interest.