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1.
Dent Mater ; 38(12): 1947-1955, 2022 12.
Article in English | MEDLINE | ID: mdl-36402644

ABSTRACT

OBJECTIVES: The aim of this study was to investigate the effect of thermal energy induced by a diode laser (445 nm) on the setting reactions of conventional glass ionomer cements (GICs) by using Fourier transform infrared spectroscopy (FTIR) and to compare it with that induced by a LED device. METHODS: Four GICs were investigated in this study (GlassIonomer FX Ultra, Ketac Universal Aplicap, Equia Fill, and Riva Self Cure). The experimental groups of the study were as follows (n = 5): Group 1 (control) - the specimens after mixing were left to set without any treatment; Group 2 - the specimens were irradiated for 60 s using a LED (Valo™) at 1400 mW/cm2 (fluence ∼ 1.4 J/cm2); Group 3 - the specimens were also irradiated for 60 s using a diode laser (SIROLaser Blue), which emits at 445 ± 5 nm with average output power of 0.7 W (fluence ∼ 1.4 J/cm2). FTIR analysis of the GIC specimens was followed to assess the changes in the COO-/CO ratios of the setting reaction and its progress in time. RESULTS: Both laser and LED treatments improved the setting reactions of the GICs compared to the control group (p < 0.05). However, this phenomenon was not observed in all materials implying that it may be material dependent. SIGNIFICANCE: Radiant heat treatments using diode laser or LED may be beneficial for the rate and progress of setting reaction of the conventional GICs. The composition and handling of the materials may be crucial for their final properties and the overall clinical behavior.


Subject(s)
Glass Ionomer Cements , Lasers, Semiconductor , Spectroscopy, Fourier Transform Infrared , Hot Temperature
2.
Int J Clin Pediatr Dent ; 15(3): 350-355, 2022.
Article in English | MEDLINE | ID: mdl-35991795

ABSTRACT

Objective: The objective of the study was to determine and compare flexural strength and microhardness of Cention N with Glass ionomer cement (GIC) (GC Gold Label Type IX Extra) and Zirconomer improved at a distinctive time period in artificial saliva. Materials and methods: Cention N, GC Gold Label Type IX Extra, Zirconomer improved for the fabrication of samples. To determine the physical properties such as flexural strength and microhardness, test samples (n-30) of dimensions 12 mm (length)*4 mm (breadth)*2 mm (thickness) were made and divided into three groups. Every sample was dipped for 28 days in a plastic tube containing 5 mL of artificial saliva. Statistical analysis was done using one-way ANOVA with a post hoc test, intergroup and intragroup analyses were carried out. Results: In an intergroup analysis, flexural strength and microhardness of Cention N were substantially higher than Zirconomer improved and GIC (GC Gold Label Type IX Extra), respectively. In intragroup analysis found that there was a significant decrease (p < 0.001) in the level of flexural strength as well as microhardness after samples were immersed in artificial saliva of group A (Cention N), group B (GC Gold Label Type IX Extra), and group C (Zirconomer improved) from 1st day to 28th day in artificial saliva. Conclusion: It can be concluded that Cention N had the highest flexural strength and microhardness of the three materials tested. Zirconomer improved can be used as a basic filling material in various restorative procedures due to good comparable mechanical properties and is economical for patients. How to cite this article: Adsul PS, Dhawan P, Tuli A, et al. Evaluation and Comparison of Physical Properties of Cention N with Other Restorative Materials in Artificial Saliva: An In Vitro Study. Int J Clin Pediatr Dent 2022;15(3):350-355.

3.
Braz. dent. sci ; 23(1): 1-11, 2020. ilus, tab
Article in English | LILACS, BBO - Dentistry | ID: biblio-1049834

ABSTRACT

Objective: to evaluate the marginal fit and microleakage of monolithic zirconia crowns cemented by bio-active cements (Ceramir) compared to that cemented with glass ionomer cement, and to evaluate the effect of thermocycling on marginal fit. Material and Methods: Twenty sound human molar teeth were prepared to receive monolithic zirconia crowns. Teeth were divided randomly into two equal groups according to the type of luting cement: Group I (glass ionomer cement) and group II (Ceramir cement). After cementation, the vertical marginal gap was assessed using stereomicroscope before and after thermocycling. Twenty equidistant measurement points were taken for each crown. Leakage assessment was carried out using Fuchsin dye penetration followed by digital photography under a stereomicroscope. Data were analyzed by Mann-Whitney U test to compare between the two luting cements. Wilcoxon signed-rank test was used to evaluate the effect of thermocycling on the marginal fit (P ≤ 0.05). Results: Whether before or after thermocycling, the results showed no significant difference between the marginal gap values of the two tested groups. For both groups, there was a significant increase in marginal gap values after thermocycling. Also, there was no significant difference between leakage scores of the two tested groups. Conclusion: Similarity in the physical properties and chemical composition of the two cements resulted in a nonsignificant effect on the vertical marginal fit and the extent of microleakage of translucent zirconia crowns. Thermocycling had a negative impact on the vertical marginal gap of the two tested luting agents. (AU)


Objetivo: avaliar a adapatação marginal e a microinfiltração de coroas monolíticas de zircônia cimentadas com cimentos bioativos (Ceramir) em comparação com o cimento de ionômero de vidro e avaliar o efeito da termociclagem na adaptação marginal. Material e Métodos: Vinte molares humanos sadios foram preparados para receber coroas monolíticas de zircônia. Os dentes foram divididos aleatoriamente em dois grupos iguais, de acordo com o tipo de cimento: Grupo I (cimento de ionômero de vidro) e grupo II (cimento Ceramir). Após a cimentação, a adaptação marginal vertical foi avaliada com estereomicroscópio antes e após a termociclagem. Vinte pontos de medição equidistantes foram obtidos para cada coroa. A avaliação da infiltração foi realizada utilizando a penetração do corante de fucsina, seguida de fotografia digital sob estereomicroscópio. Os dados foram analisados pelo teste de Mann-Whitney para comparação entre os dois cimentos. O teste de Wilcoxon foi usado para avaliar o efeito da termociclagem na adaptação marginal (P ≤ 0,05). Resultados: Antes ou depois da termociclagem, os resultados não mostraram diferença significativa entre os valores de fenda marginal dos dois grupos testados. Para ambos os grupos, houve um aumento significativo nos valores de fenda marginal após a termociclagem. Além disso, não houve diferença significativa entre os escores de infiltração dos dois grupos testados. Conclusão: A similaridade nas propriedades físicas e na composição química dos dois cimentos resultou em um efeito não significativo na adaptação marginal vertical e na extensão da microinfiltração de coroas translúcidas de zircônia. A termociclagem teve um impacto negativo na fenda marginal vertical dos dois agentes de cimentação testados. (AU)


Subject(s)
Humans , Zirconium , Dental Marginal Adaptation , Crowns , Dental Cements , Dental Leakage , Temperature , In Vitro Techniques , Random Allocation , Glass Ionomer Cements , Molar
4.
J Indian Soc Pedod Prev Dent ; 37(3): 265-270, 2019.
Article in English | MEDLINE | ID: mdl-31584026

ABSTRACT

PURPOSE: The study aimed to evaluate and compare the compressive strength and surface microhardness of EQUIA Forte, light cure, and conventional glass-ionomer cement (GIC). METHODOLOGY: Fifty-four pellets of G-Coat (GC) Gold Label 2, GC Gold Label light-cured universal restorative material, and EQUIA Forte GIC were prepared of dimensions (6 × 4) mm and were divided into three groups (18) each and were stored at 37°C for 1 h and then immersed in 20 ml of deionized water, artificial saliva, and lactic acid six each, respectively, over 30 days. Samples were subjected to surface microhardness and compressive strength test on the 1st day, 7th day, and 30th day. Results were subjected to ANOVA and Bonferroni post hoc test. RESULTS: Comparing the compressive strength of EQUIA Forte from day 1 to 30 when placed in artificial saliva, there was a significant increase on day 30 (P = 0.007); compared to other groups. The surface microhardness of EQUIA Forte from day 1 to 30 when placed in artificial saliva nonsignificantly decreased comparing to other groups. CONCLUSION: Surface microhardness and compressive strength of EQUIA Forte were significantly high in comparison to the other groups.


Subject(s)
Dental Materials , Glass Ionomer Cements , Compressive Strength , Materials Testing , Saliva, Artificial
5.
J Conserv Dent ; 22(5): 420-424, 2019.
Article in English | MEDLINE | ID: mdl-33082655

ABSTRACT

AIM: The aim of this study is to evaluate and compare the fracture resistance of endodontically treated teeth using four intraorifice barriers. MATERIALS AND METHODS: Fifty extracted single-rooted mandibular premolars were selected, decoronated, and prepared with rotary Protaper universal system and obturated with gutta-percha and AH Plus sealer. Samples were divided into five groups (n = 10) on the basis of intraorifice barrier material used. Group 1: Biodentine, Group 2: Conventional glass ionomer cement (GIC), Group 3: Resin-modified glass ionomer cement (RMGIC), Group 4: Nanohybrid composite, Group 5: No barrier (control).Except for control specimens, coronal 3-mm gutta-percha was removed and filled with different intraorifice barrier materials in respective groups. Fracture resistance of specimens was tested using universal testing machine. STATISTICAL ANALYSIS USED: One-way analysis of variance test and Post hoc Tukey's test. RESULTS: Mean fracture resistance of all experimental groups (with intraorifice barriers placed) were higher than control group (no intraorifice barrier placed). Biodentine showed the highest mean fracture resistance while RMGIC showed the least and the difference between their mean fracture resistance was statistically significant. There was no statistically significant difference among other experimental groups. CONCLUSION: Placement of intraorifice barriers in endodontically treated teeth can significantly increase fracture resistance and this increase in fracture resistance is material dependent.

6.
Indian J Dent Res ; 29(6): 744-748, 2018.
Article in English | MEDLINE | ID: mdl-30589002

ABSTRACT

AIM: The aim of this in vitro study was to evaluate and compare the effect of protective coating G-Coat Plus on microleakage of conventional glass ionomer cement (CGIC) and resin-modified glass ionomer cement (RMGIC) in primary molars. MATERIALS AND METHODS: A total of 120 samples were divided into four groups with 30 samples in each group. Group A - teeth restored with CGIC. Group B - teeth restored with CGIC coated with G-Coat Plus. Group C - teeth restored with RMGIC. Group D - teeth restored with RMGIC coated with G-Coat Plus. Microleakage was tested using 2% basic fuschin dye penetration and measured at ×40 original magnification under the stereomicroscope. RESULTS: The results of this in vitro study showed that coating with G-Coat Plus showed a reduction in microleakage in CGIC and complete absence of microleakage in RMGIC when compared to the noncoated groups, which was statistically significant. CGIC without G-Coat Plus showed highest microleakage followed by RMGIC without G-Coat Plus, followed by a relatively less microleakage in CGIC with G-Coat Plus. CONCLUSION: Significant reduction in microleakage was seen in conventional GIC and RMGIC with G-Coat Plus when compared to conventional GIC and RMGIC without G-Coat Plus.


Subject(s)
Dental Leakage/prevention & control , Glass Ionomer Cements , Molar , Resins, Synthetic , Tooth, Deciduous , Humans , In Vitro Techniques
7.
ACS Appl Mater Interfaces ; 10(12): 9904-9915, 2018 Mar 28.
Article in English | MEDLINE | ID: mdl-29504390

ABSTRACT

Hydrogen dynamics in a time range from hundreds of femtoseconds to nanoseconds can be directly analyzed using neutron spectroscopy, where information on the inelastic and quasi-elastic scattering, hereafter INS and QENS, can be obtained. In this study, we applied these techniques to understand how the nanoscale mobility of the aqueous solution of polyacrylic acid (PAA) used in conventional glass ionomer cements (GICs) changes under confinement. Combining the spectroscopic analysis with calorimetric results, we were able to separate distinct motions within both the liquid and the GICs. The QENS analysis revealed that the self-diffusion translational motion identified in the liquid is also visible in the GIC. However, as a result of the formation of the cement matrix and its setting, both translational diffusion and residence time differed from the PAA solution. When comparing the local diffusion obtained for the selected GIC, the only noticeable difference was observed for the slow dynamics associated with the polymer chain. Additionally, over short-term aging, progressive water binding to the polymer chain occurred in one of the investigated GICs. Finally, a considerable change in the density of the GIC without progressive water binding indicates an increased polymer cross-linking. Taken together, our results suggest that accurate and deep understanding of polymer-water binding, polymer cross-linking, as well as material density changes occurring during the maturation process of GIC are necessary for the development of advanced dental restorative materials.

8.
J Dent ; 69: 102-109, 2018 02.
Article in English | MEDLINE | ID: mdl-29253621

ABSTRACT

OBJECTIVES: This work aimed (1) to develop polyacid formulations by the one-step photoreduction of silver nanoparticles (AgNP) in a polyacrylate solution of conventional glass ionomer cement (GIC), imparting antibacterial activity; and (2) to evaluate handling and mechanical properties of experimental ionomers in comparison to a commercially available conventional GIC. METHODS: Formulations with increasing sub-stoichiometric amounts of AgNO3 were monitored during continuous UV light exposure by UV-vis spectroscopy and analyzed by transmission electron microscopy. The resulted synthesis of formulations containing small and disperse spherical nanoparticles (∼6 nm) were used to design the experimental nano-silver glass ionomer cements (NanoAg-GIC). The cements were characterized as to net setting time and compressive strength according to ISO 9917-1:2007 specifications. The antibacterial activity of these cements was assessed by Ag+ diffusion tests on nutritive agar plates (E. coli) and by MTT assay (S. mutans). RESULTS: The higher concentration of silver (0.50% by mass) in the matrix of NanoAg-GIC allowed viable net setting time and increased in 32% compressive strength of the experimental cement. All groups containing AgNP induced statistically significant E. coli growth inhibition zones (p-value <.05), indicating diffusion of Ag+ ions on the material surroundings. Metabolic activity of S. mutans grown on NanoAg-GIG with higher concentration of silver was significantly affected compared to control (p-value <.01). CONCLUSIONS: Silver nanoparticles one-step preparation in polyacrylate solution allowed the production of highly bioactive water-based cements within suitable parameters for clinical use and with large potential of dental and biomedical application.


Subject(s)
Anti-Bacterial Agents/pharmacology , Compressive Strength , Glass Ionomer Cements/chemistry , Metal Nanoparticles/chemistry , Silver/chemistry , Silver/pharmacology , Disk Diffusion Antimicrobial Tests , Escherichia coli/drug effects , Kinetics , Materials Testing , Microbial Viability/drug effects , Nanocomposites/chemistry , Particle Size , Silver Nitrate/chemistry , Streptococcus mutans/drug effects , Time Factors
9.
ARS med. (Santiago, En línea) ; 43(2): 33-41, 2018. Tab
Article in Spanish | LILACS | ID: biblio-1022877

ABSTRACT

Las lesiones cervicales no cariosas son condiciones patológicas no bacterianas localizadas en el límite amelocementario de los dientes. Los principales biomateriales descritos para el tratamiento restaurador de estas lesiones son: vidrios ionómeros, vidrios ionómeros modificados con resinas, compómeros y resinas compuestas. El objetivo de este protocolo, consiste en establecer los elementos metodológicos de una revisión sistemática que evaluará el comportamiento clínico de restauraciones cervicales realizadas con estos biomateriales. Métodos: El protocolo fue diseñado, y será reportado, en línea con Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P 2015). Se realizará una búsqueda sensible en MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials y ClinicalTrials.gov, sin restricción por lenguaje o publicación, para identificar ensayos controlados aleatorizados que comparen dos o más tratamientos restauradores en lesiones cervicales no cariosas. Los desenlaces a evaluar serán la retención de las restauraciones y caries secundaria, según criterios RYGE/USPHS. Al menos dos investigadores realizarán de manera independiente la selección de los ensayos y la extracción de los datos. El riesgo de sesgo será evaluado utilizando la herramienta recomendada por la colaboración Cochrane. Si es posible, se realizará un metanálisis y los datos serán presentados en tablas de resúmenes de resultados mediante el método Grading of Recommendations Assesment, Development and Evaluation (GRADE). Fortalezas y debilidades: Esta revisión sistemática entregará evidencia actualizada sobre el comportamiento de cuatro biomateriales en el tratamiento de lesiones cervicales no cariosas. La principal limitación proviene de la baja cantidad o deficiencias metodológicas de los estudios primarios. Número de registro (PROSPERO): CRD42017071114.(AU)


Non-carious cervical lesions constitute a group of non-bacterial pathological conditions of the dental structure located at amelocementary junction. The main dental materials that have been described for the restorative treatment of these lesions are: ionomer glass, resin modified ionomer glass, compomers and composite resins. The objective of this protocol, is to establish the methodological elements of a systematic review, that will evaluate the clinical behavior of cervical restorations performed with four dental biomaterials. Methods: The protocol was designed, and will be reported, in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyzes Protocols (PRISMA-P 2015). We will conduct a sensitive search in MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov, without language or publication restrictions, in order to identify randomized controlled trials comparing two or more restorative treatments in non-carious cervical lesions. The evaluated outcomes will be retention of restorations and secondary caries, according to RYGE/USPHS criteria. At least two reviewers will independently select studies and extract data. The risk of bias will be assessed using the tool recommended by the Cochrane Collaboration. If possible, a meta-analysis will be performed and the data will be presented in summary tables of results using the Grading of Recommendations Assesment, Development and Evaluation (GRADE) approach. Strength and Limitations: This systematic review will provide updated evidence on the behavior of four different dental biomaterials in the treatment of non-carious cervical lesions. The main limitation might arise from the low number or methodological limitations of primary studies. Register number (PROSPERO): CRD42017071114.(AU)


Subject(s)
Humans , Male , Female , Neck Injuries , Glass , Meta-Analysis , Composite Resins , Compomers
10.
J Clin Diagn Res ; 10(4): ZC73-5, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27190957

ABSTRACT

INTRODUCTION: Glass Ionomer Cement (GIC) is well known for its fluoride releasing property but has its own drawbacks of poor mechanical properties, sensitivity to initial desiccation and moisture contamination. To overcome these, search led to the reinforcement of hydroxyapatite and application of surface coating agent but their effect on fluoride release is still not clear. AIM: To evaluate and compare the release of fluoride from Hydroxyapatite Reinforced Glass Ionomer (HA-GIC) with and without protective coating. MATERIALS AND METHODS: Specimens were prepared as follows- Eight percent by weight conventional glass ionomer was replaced by hydroxyapatite powder (HA) and an indigenous product was prepared (HA-GIC). This powder was mixed with liquid of conventional GIC and allowed to set, then G coat plus coating agent was applied in surface coated group and light cured. Fluoride release of the sample was measured every 24 hrs for seven days and weekly from 7(th) to 21(st) day using combination ion selective electrode. RESULTS: Mean values clearly reveal a significant decrease in the fluoride release from day 1 to day 21 for both the groups. Results of repeated measure ANOVA revealed statistically significant difference between two groups (p <0.001). CONCLUSION: Coating the hydroxyapatite reinforced glass ionomer will allow for slow and steady release of fluoride for a long period of time into oral environment.

11.
J Dent (Shiraz) ; 17(1): 1-6, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26966701

ABSTRACT

STATEMENT OF THE PROBLEM: In the sandwich technique, the undesirable bond between the composite resin and glass-ionomer cement (GIc) is one of the most important factors which lead to the failure of restoration. Total-etch and self-etch adhesives may improve the bond strength based on their pH. PURPOSE: The purpose of this study was to evaluate the shear bond strength between the nanofilled composite resin and GIc using different adhesives. MATERIALS AND METHOD: In this experimental study, 40 specimens (6×6mm) in 4 groups (n=10) were prepared in acrylic mold. Each specimen contained conventional GI ChemFil Superior with a height of 3mm, bonded to Z350 composite resin with a height measured 3mm. In order to bond the composite to the GI, the following adhesives were used, respectively: A: mild Clearfil SE Bond self-etch (pH=2), B: intermediate OptiBond self-etch (pH=1.4), C: strong Adper Prompt L-Pop (pH=1), and D: Adper Single Bond 2 total-etch (pH=7.2). The shear bond strength was measured by using universal testing machine with a crosshead speed of 1mm/min. One-way ANOVA and Tukey's test were used to analyze the data (p< 0.05). RESULTS: The shear bond strength in group A was significantly higher than group B (p= 0.002), C (p< 0.001), and D (p< 0.001). Moreover, the shear bond strength of groups A and B (self-etch) was significantly different from group D (total-etch) (p< 0.001); and C (self-etch) with D (p= 0.024). CONCLUSION: The results of this study showed that applying the mild self-etch adhesive between the composite and the GIc results in stronger shear bond strength compared to intermediate and strong self-etch adhesives. Moreover, the self-etch adhesive increased the shear bond strength between composite resin and GIc more significantly than total-etch adhesive.

12.
Eur J Dent ; 9(2): 176-182, 2015.
Article in English | MEDLINE | ID: mdl-26038646

ABSTRACT

OBJECTIVE: This study was conducted to evaluate the microshear bond strength (µSBS) and ultramorphological characterization of glass ionomer (GI) cements; conventional GI cement (Fuji IX, CGI), resin modified GI (Fuji II LC, RMGI) and nano-ionomer (Ketac N100, NI) to enamel, dentin and cementum substrates. MATERIALS AND METHODS: Forty-five lower molars were sectioned above the cemento-enamel junction. The occlusal surfaces were ground flat to obtain enamel and dentin substrates, meanwhile the cervical one-third of the root portion were utilized to evaluate the bonding efficacy to cementum substrate. Each substrate received microcylinders from the three tested materials; which were applied according to manufacturer instructions. µSBS was assessed using a universal testing machine. The data were analyzed using two-way analysis of variance (ANOVA) and Tukey's post-hoc test. Modes of failure were examined using stereomicroscope at ×25 magnification. Interfacial analysis of the bonded specimens was carried out using environmental field emission scanning electron microscope. RESULTS: Two-way ANOVA revealed that materials, substrates and their interaction had a statistically significant effect on the mean µSBS values at P values; ˂0.0001, 0.0108 and 0.0037 respectively. RMGI showed statistically significant the highest µSBS values to all examined tooth substrates. CGI and RMGI show substrate independent bonding efficiency, meanwhile; NI showed higher µSBS values to dentin and cementum compared to enamel. CONCLUSION: Despite technological development of GI materials, mainly the nano-particles use, better results have not been achieved for both investigations, when compared to RMGI, independent of tooth substrate.

13.
J Int Oral Health ; 7(3): 53-8, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25878480

ABSTRACT

BACKGROUND: Cervical lesions of anterior and posterior teeth are a common finding in routine dental practice. They are of much concern to the patient, if present in esthetically sensitive regions. Adhesive tooth-colored restorative materials are generally recommended for treating such lesions. The aim of the present study was to evaluate and compare the effect of various food media (lime juice, tea, coffee, and Coca-Cola) on the marginal integrity of Class V compomer (Dyract(®)), conventional glass-ionomer (Fuji II) and resin-modified glass-ionomer (Fuji II LC improved) restorations along their cemental and enamel margins with saline as control media. MATERIALS AND METHODS: After restoration of prepared Class V cavities in human premolars with the three different materials (n = 8), they were immersed in the test media for 7 days and then stained with methylene blue dye. Buccolingual sections were prepared and examined under stereomicroscope and scores (0-2) were given. RESULTS: Data were analyzed statistically using one-way analysis of variance in SPSS version 16.0. P < 0.05 were considered statistically significant. CONCLUSIONS: Among the three tested materials Compomer (Dyract(®)) showed more marginal integrity than the other two. Micro leakage values of Fuji II and Fuji II LC improved were statistically significant in acidic media (lime juice and Coca-Cola) compared to saline. Enamel margins showed more marginal adaptation than cemental margins.

14.
Ann Stomatol (Roma) ; 5(1): 15-22, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24753797

ABSTRACT

AIM: The aim of this in vitro study was to evaluate the effect of different surface treatments on shear bond strength of a conventional glass-ionomer cement (GIC) and a resin-modified glass-ionomer cement (RMGIC) to dentin. MATERIALS AND METHODS: 80 bovine permanent incisors were used. 40 cylindrical specimens of a GIC (Fuji IX GP Extra) and 40 cylindrical specimens of a RMGIC (Fuji II LC) were attached to the dentin. The teeth were then randomly assigned to 8 groups of equal size (n=10), 4 for every type of glass-ionomer cement, corresponding to type of dentin surface treatments. Group 1: GC Cavity Conditioner; Group 2: 37% phosphoric acid gel; Group 3: Clearfil SE Bond; Group 4: no dentin conditioning (control). The specimens were placed in a universal testing machine (Model 3343, Instron Corp., Canton, Mass., USA) and subsequently tested for shear bond strength (MPa). RESULTS: ANOVA showed the presence of significant differences among the various groups. Post hoc Tukey test showed different values of shear bond strength for Fuji IX GP Extra and for Fuji II LC. The different conditioners variably influence the adhesion of the glass-ionomer cements tested. Conclusions. RMGIC shear bond to dentin was higher than GIC. The use of a Self-etch adhesive system improved the shear bond strength values of RMGIC and lowered the shear bond strength values of GIC significantly.

15.
J Mech Behav Biomed Mater ; 29: 427-37, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24189324

ABSTRACT

OBJECTIVE: The aim of this study was to investigate the interfacial work of fracture of conventional (C-) and resin-modified (RM-) glass-ionomer cements (GICs) bonded to dentin. METHODS: One hundred and sixty five aries-free human molars were embedded in epoxy resin, sectioned and polished with 300- and 600- grit silicon carbide paper to remove enamel on the occlusal surface. Equilateral triangular-shaped plastic molds (4×4×4×5mm(4)) were clamped to the prepared dentin surfaces by a stainless steel test apparatus. Teflon tape was placed under one internal vertex of the mold to create a 0.1-mm notch at the material-dentin interface. Interfacial work of fracture (γwofint) in tensile fracture mode-I (opening) was determined for six C-GIC, three RM-GIC, and two GIC luting cements at a cross-head speed of 0.1mm/min and a crosshead distance (L) from the interface of 4.3mm. The debonded surfaces were evaluated for the predominant failure mode. SEM analysis of examples showing interfacial and notch areas was performed. RESULTS: ANOVA and Tukey's post hoc test demonstrated the highest mean γwofint value (90.16±16.6J/m(2)) of one RM-GIC was significantly different (p<0.05) from the other materials. 'High viscosity' GICs achieved lower results with the lowest recorded at 20.4±10.1J/m(2). There was a significant difference observed (p<0.05) between the mean γwofint of luting C-GIC and luting RM-GIC. Although differences were observed between different material mean γwofint, when comparing groups no significant differences (p=0.181) were observed. For all groups, mixed GIC-interface failure (41%) was the most commonly observed, followed by cohesive failure in GIC (25%) and adhesive failure (20%). SEM analysis revealed that specimens generally fractured from the notch initiation point into the GIC or along the dentin-GIC interface. CONCLUSION: Within the limits of this study, significant differences (p<0.05) were observed in the γwofint between different glass-ionomer materials. The null hypothesis that there is no difference in the γwofint among different glass-ionomer materials bonded to human dentin was rejected. RELEVANCE: In the current study, the interfacial work of fracture (γwofint) of glass-ionomer adhesive interfaces has been reported using a simple method that can be used to study the fracture mechanics of an adhesive interface without the need for complicated specimen preparation.


Subject(s)
Dentin-Bonding Agents , Dentin , Glass Ionomer Cements , Materials Testing , Mechanical Phenomena , Humans , Resins, Synthetic
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