Comparison of Dentin Caries Remineralization with Four Bioactive Cements.

The treatment of deep carious lesions involves the use of ion-releasing agents to seal the lesions. These agents release minerals, leading to the remineralization of the remaining demineralized dentin. This study aimed to compare the dentin caries remineralization with bioactive cements. 60 Dentin blocks were prepared from the dentin of human third molars. Artificial carious lesions were induced on the blocks with pH cycling. The samples were divided into five groups (n=12). Dycal, Oxford ActiveCal PC, Biodentine, and ACTIVA BioACTIVE were applied using a mold. One group did not receive any cement. The samples were stored in remineralization solution for 30 days. The cement was removed using a #15 blade, and the dentin surface was evaluated using Energydispersive X-ray Spectroscopy and X-ray Diffraction. One-way ANOVA did not show a significant difference in the weight percentages of calcium and phosphorus and the calcium-to-phosphorus ratios between the groups. The highest and the lowest weight percentages of calcium and phosphorus were observed in Biodentine and control groups, respectively. There were no significant differences in the remineralization properties of bioactive cements. Hydroxyapatite crystals were not formed in any of the adjacent dentin using these cements.

Cytotoxic Evaluation and Determination of Organic and Inorganic Eluates from Restorative Materials.

Over the last years, diverse commercial resin-based composites have dominated as dental filling materials. The purpose of the present study was to determine organic and inorganic eluates from five restorative materials using GC/MS and ICP-OES and to compare the effect on cell survival of human gingival fibroblasts of a conventional and a bioactive resin. Five commercially available restorative materials were employed for this study: ActivaTM Bioactive Restorative, ENA HRi, Enamel plus HRi Biofunction, Fuji II LC Capsule, and Fuji IX Capsule. Disks that were polymerized with a curing LED light or left to set were immersed in: 1 mL methanol or artificial saliva for GC/MS analysis, 5mL deionized water for ICP-OES, and 5mL of culture medium for cell viability. Cell viability was investigated with a modified staining sulforhodamine B assay.The following organic substances were detected: ACP, BHT, BPA, 1,4-BDDMA, CQ, DBP, DMABEE, HEMA, MCE, MeHQ, MOPA, MS, TMPTMA, and TPSb and the ions silicon, aluminum, calcium, sodium, and barium. Activa Bioactive Restorative was found to be biocompatible. Elution of organic substances depended on material's composition, the nature of the solvent and the storage time. Ions' release depended on material's composition and storage time. The newly introduced bioactive restorative was found to be more biocompatible.

Sorción de humedad y resistencia a la disolución ácida de dos ionómeros de vidrio de restauración: estudio in vitro / Sorption of moisture and resistance to acid dissolution of two restoration glass ionomers: in vitro study

Resumen Introdución: En general el Ionómero de vidrio tiene algunas desventajas en la parte clínica, como es la fragilidad y la sensibilidad inicial a la humedad, lo que puede causar una disminución de la vida útil de la restauración. Estos efectos que sufre el ionómero como la sorción de humedad y la solubilidad a los ácidos puede causar daño a la restauración, facilitar su fractura y filtración marginal, lo que puede conllevar a una recidiva de caries y pérdida de sus propiedades. Objetivo: comparar in vitro la sorción de humedad y disolución ácida de dos ionómeros de restauración. Método: Se elaboraron 20 muestras de ionómero de vidrio Ketac molar y 20 de Fuji II. Se realizó una primera medición del peso con balanzas de precisión, obteniéndose un peso inicial. Los especímenes fueron sumergidos en agua destilada durante 24 horas, almacenadas en un calefactor; cada muestra fue pesada con una balanza de precisión, estableciéndose el porcentaje de humedad sorbida a partir del peso inicial. Posteriormente las muestras fueron sumergidas en solución de ácido cítrico al 3% durante 24 horas, para volver a ser pesadas, evaluándose la perdida de material por acción erosiva del ácido en porcentaje de peso. Conclusiones: La sorción de humedad en peso fue de 2,59% en el ketac molar y 1,45% en el Fuji II; al comparar las muestras mediante la prueba t, se obtuvo diferencias estadísticamente significativas. El porcentaje de pérdida de material por acción erosiva del ácido fue de 10,81% para Ketac molar y 18,62% para el Fuji II; al comparar las muestras mediante la prueba t, se obtuvo diferencias estadísticamente significativas. Se concluyó que la sorción de humedad fue mayor en el Ketac molar y la mayor solubilidad a la acción del ácido cítrico fue del Fuji II.

Abstract Introduction: Glass Ionomer has certain clinical disadvantages, such as fragility and moisture sensitivity, which might reduce the restauration´s lifespan. This effects, such as water absorption and acid solubility may damage the restauration, cause fracture and marginal filtration, this could trigger cavity relapse and the loss of the correct mechanical properties. Objective: Compare in vitro moisture sorption and acid solution of two restoration ionomers. Method: 20 samples of Ketac molar glass ionomer and 20 of Fuji II were made. A first weight measurement was made with precision scales, obtaining an initial weight. The specimens were submerged in distilled water for 24 hours, stored in a heater; Each sample was weighed with a precisión balance, establishing the percentage of moisture absorbed from the initial weight. Subsequently, the samples were submerged in 3% citric acid solution for 24 hours, to be re-weighed, evaluating the loss of material due to erosive action of the acid in percentage of weight. Conclusions: The moisture sorption by weight was 2.59% in the molar ketac and 1.45% in the Fuji II; When comparing the samples using the t-test, statistically significant differences were obtained. The percentage of material loss due to erosive action of the acid was 10.81% for molar Ketac and 18.62% for Fuji II; When comparing the samples using the t-test, statistically significant differences were obtained. It was concluded that the moisture sorption was higher in the molar Ketac and the greatest solubility to the action of citric acid was Fuji II.

Organic Eluates Derived from Intermediate Restorative Dental Materials.

A great number of different types of materials have been used in dentistry as intermediate restoratives. Among them, new resin-based bases have been released in the dental market. The present study focuses on the identification of the organic eluates released from such materials and the study of their surface microstructure in combination with their corresponding elemental composition. For this purpose, the following materials were used:ACTIVA™BioACTIVE-BASE/LINER™, Ketac™Bond Glass Ionomer, SDR™ and Vitrebond™Light Cure Glass Ionomer Liner/Base. Methanolic leachates derived from polymerized materials were analyzed by means of gas chromatography-mass spectrometry (GC-MS). Scanning electron microscopy(SEM) was used for the surface monitoring of suitably prepared specimens. The GC-MS analysis revealed the elution of twenty different substances from the three resin-based materials, while none was eluted from the glass ionomer base. The SEM analysis for Vitrebond™ presented small pits, the one for Ketac™Bond presented elongated cracks, while no voids were present for ACTIVA™BioACTIVE-BASE/LINER™ and SDR™. Moreover, the resin matrix of some dental materials may inhibit elements' accumulation on the surface layers. Particularly, the detected organic eluents may be related to potential toxic effects.

Forensic study of mechanical properties of dental restoration after burial in mangrove environment.

Conducting research in the field of forensic sciences with methodologies that simulate situations found in the day-to-day practice of a given field of expertise is relevant insofar as this approach can produce results that are as close as possible to reality. In this context, the present study provided situations based on burial in a mangrove environment to estimate the changes in the mechanical properties (Knoop microhardness, roughness and color) of dental restorations utilizing silver amalgam, composite resin and glass ionomer cement over the time of burial. The silver amalgam showed a significant increase in surface roughness and a reduction in Knoop microhardness. Composite resin showed a statistically significant increase in color variation, and the glass ionomer cement showed significant increases in color variation and Knoop microhardness. These results allowed us to conclude that teeth restored with silver amalgam, composite resin and glass ionomer cement submitted to burial in mangrove environments produce different changes in surface roughness, Knoop microhardness and color properties depending on the time of burial to which the victims were submitted. These proprieties could help the forensic sciences to estimate time intervals for burial in mangrove environments.

Effect of Ions Released and pH of Two Glass Ionomer Cements in Human Gingival Fibroblasts / Efecto de la liberación de iones y pH de dos cementos de ionómero de vidrio en fibroblastos gingivales humanos

Abstract 20. Conventional glass ionomer cements are used as dental provisional restorative materials, which present several advantages such as adhesion to the tooth mineral phase among others. On the other hand, the knowledge about biological property of glass ionomers shows various approaches and results. In this work, it was studied the in vitro biological response of human gingival fibroblasts in contact with commercial cements of glass ionomer: Mirafil® and Ionglass® and with their extracts, according to ISO 10993. The extracts of the cements, in which the cells were cultured, were adjusted at different concentrations ranging 0.1% to 100%. The cellular metabolic activity of gingival fibroblasts was measured using the Alamar Blue® reagent. The results showed a significant effect on the cellular metabolic activity correlated with the concentration of liberated ions (Al³+ and Ca²+) for both ionomers, as well as the pH variations of the culture media. This could mean that the cellular metabolic activity is substantially influenced by ions and pH of the cell culture.

Resumen 24. Los cementos de ionómero de vidrio convencionales se utilizan como materiales de restauración provisional para uso dental, los cuales presentan varias ventajas como la adhesión a la fase mineral de los dientes. Por otro lado, las propiedades biológicas de los ionómeros de vidrio muestran diversos enfoques y resultados. En éste trabajo se estudió la respuesta biológica in vitro de fibroblastos gingivales humanos en contacto con cementos comerciales de ionómero de vidrio: Mirafil® e Ionglass® y con sus respectivos extractos según la norma ISO 10993. Los extractos de los cementos en los que se cultivaron las células estaban en diferentes concentraciones: de 0.1% a 100%. La actividad metabólica celular se midió usando el reactivo Alamar Blue®. Los resultados mostraron un efecto significativo sobre la actividad metabólica celular correlacionada con la concentración de iones liberados (Al³+ y Ca²+) para ambos ionómeros, así como las variaciones de pH de los medios de cultivo. Ello podria explicar la influencia por los iones y el pH del cultivo celular en la actividad metabólica celular.

Efficacy of Sealing with Glass Ionomer Cement and Transversal Brushing Technique in Erupting First Molars: 18-Month Clinical Follow-Up

Objective: To verify the effectiveness of sealing with glass ionomer cement and transversal brushing in the prevention and treatment of initial caries lesions in erupting permanent molars of children aged 5-7 years. Material and Methods: Healthy teeth with ICDAS scores 1 or 2 were selected. One hundred and thirty-one children (79 teeth in the control group - 75 teeth in the test group) were randomly assigned into the two experimental groups: (1) transversal brushing technique for plaque control with conventional flat bristles and fluoridated dentifrice or (2) sealing the occlusal surfaces with glass ionomer cement (Vitro Molar®). Follow-up was performed for 18 months and the survival analysis was applied to test the occurrence of lesion progression. Results: The mean age of children was 5.4 years and it was verified that, by examining the initial tooth condition, the probability of progression was 66% lower when the tooth had initial caries lesions than when it was healthy; the probability of molar progression was about 74% lower in the test group compared to the control group. The mean time for lesion development in the test group (16.8 months; SD = 0.5) was greater than that in the control group (16.5 months; SD = 0.5; p=0.008). Conclusion: Sealing reduces the progression of caries disease in initial lesions when compared to the transversal brushing technique.

Performance of Preventive Methods Applied to the Occlusal Surface of Primary Teeth: A Randomized Clinical Study

Objective: To evaluate the clinical performance of three preventive materials on the occlusal surfaces of primary molars over a 36-month period. Material and Methods: The study was conducted with a split-mouth design involving four experimental groups: G1 ­ resin-modified glass ionomer cement (Vitremer®); G2 - resin sealant (Alpha Seal Light®); G3 - silver diamine fluoride (Cariostatic®); and G4 - control group without material. Thirty-two children aged 36 to 60 months, attending a pediatric clinic, with a deft index ≥ 1 and four primary second molars participated in the study. The material retention was evaluated in G1 and G2, and the presence of incipient caries was evaluated in all groups. Data were submitted to the Wilcoxon test and survival test (α = 5%). Results: At three, six, 12, 24 and 36 months, G2 exhibited greater material loss (maximum loss: 44%) in comparison to G1 (maximum loss: 35%), but this difference did not achieve statistical significance (p = 0.214). The highest incidence of incipient caries occurred in G3 (20%), but no significant differences were found between groups at any evaluation time (p = 0.154). Conclusion: There were no statistically significant differences between the evaluated products regarding material retention and dental caries, although there was more material loss in teeth that received the Alpha Seal® sealant resin, and a greater number of carious lesions in the Cariostatic® group (silver diamine fluoride).

Exploring the unexpected influence of the Si:Ge ratio on the molecular architecture and mechanical properties of Al-free GICs.

Germanium (Ge)-based glass ionomer cements have demonstrated the ability to balance strength with extended setting times, a unique set of characteristics for aluminum-free glass ionomer cements. However, the mechanical properties of current Ge-based glass ionomer cements significantly deteriorate over time, which jeopardizes their clinical potential. This work explores the effect of incrementally decreasing the Si:Ge ratio in the glass phase of zinc-silicate glass ionomer cements to identify potential mechanisms responsible for the time-induced mechanical instability of Ge-based glass ionomer cements. The influence of Ge was evaluated on the basis of changes in mechanical properties and molecular architecture of the cements over a 180-day period. It was observed that the compressive strength and modulus of the cements were sustained when Si:Ge ratios were ≥1:1, but when Si:Ge ratios are <1:1 these properties decreased significantly over time. These mechanical changes were independent of structural changes in the glass ionomer cement matrices, as the level of metal-carboxylate crosslinks remained constant over time across the various Si:Ge ratios explored. However, it was noted the temporal decline of mechanical properties was proportional to the increased release of degradation byproducts, in particular Ge that was released from the cements in substantially greater quantities than other glass constituents. Unexpectedly, the slowest setting cement (Si:Ge 1:1) was also the strongest; behavior that is uncommon in Si-based glass ionomer cements, supports the potential of Ge-containing glass ionomer cements as injectable bone cements in applications such as percutaneous vertebroplasty.

Glass-ionomer Cements in Restorative Dentistry: A Critical Appraisal.

Glass-ionomer cements (GICs) are mainstream restorative materials that are bioactive and have a wide range of uses, such as lining, bonding, sealing, luting or restoring a tooth. Although the major characteristics of GICs for the wider applications in dentistry are adhesion to tooth structure, fluoride releasing capacity and tooth-colored restorations, the sensitivity to moisture, inherent opacity, long-term wear and strength are not as adequate as desired. They have undergone remarkable changes in their composition, such as the addition of metallic ions or resin components to their composition, which contributed to improve their physical properties and diversified their use as a restorative material of great clinical applicability. The light-cured polymer reinforced materials appear to have substantial benefits, while retaining the advantages of fluoride release and adhesion. Further research should be directed towards improving the properties, such as strength and esthetics without altering its inherent qualities, such as adhesion and fluoride releasing capabilities.

Assessment of Glass Ionomer Cements (GIC) Restorations after Acidic Erosive Challenges: An in vitro Study

Objective: To analyze the marginal adaptation of two different Glass Ionomer Cements (GIC) after erosive challenges. Material and Methods: Sixty sound extracted primary canines were selected and class V cavities were made. Teeth were allocated into 6 groups according to restorative material: 1) high-viscosity GIC (Ketac™Molar Easymix) and 2) resin-modified GIC with nanoparticles (Ketac™N100), low pH beverage erosive challenge (Orange juice and Coca-Cola) or distilled water as control. Thereafter the sample was restored and subjecting to thermocycling. The sample was immersed for a 10-days period for the erosive simulation and then embedded in methylene blue solution during 4 hours. Finally teeth were sectioned for further analysis. Marginal adaptation test was performed by two trained examiners using the Salama et al. criteria. Descriptive and Kruskal-Wallis test (α=5%) were used to analyze the data. Results: The groups treated with Ketac™Molar EasyMix were similar in terms of marginal sealing ability when submitted to Orange juice and Coca-Cola but significantly worse than water. For samples restored with the Ketac™N100 the worst results were found in the Coca-Cola group. Conclusion: Erosive challenges with acidic drinks affected the marginal adaptation of the tested GIC.

Influência da densidade tubular em diferentes profundidades dentinárias na estabilidade de união de cimentos de iônomero de vidro / Influence of tubular density in diferent dentin depths in bonding stability of glass ionomer cements

O objetivo do estudo foi avaliar a influência da densidade tubular em diferentes profundidades dentinárias na estabilidade de união de dois cimentos de ionômero de vidro (CIV) de alta viscosidade. Vinte terceiros molares foram alocados em 6 grupos experimentais, de acordo com a profundidade da dentina - proximal, oclusal superficial ou oclusal profunda, e os CIVs - Fuji IX (GC Corp.) e Ketac(TM) Molar Easy Mix (3M/ESPE). Inicialmente os dentes foram cortados a fim de se obter fatias de aproximadamente 1 mm de espessura de dentina proximal, oclusal superficial e profunda. Em seguida, foi realizado uma análise topográfica das secções das diferentes superfícies e profundidades em microscopia confocal a laser (100X) para obtenção das médias da densidade tubular em cada profundidade. Cânulas de polietileno foram então posicionadas sobre as secções de dentina pré-tratadas e preenchidas pelos CIVs. Os espécimes foram armazenados em água destilada por 24 h e 12 meses a 37°C, em seguida foram submetidos ao ensaio de microcisalhamento (0,5 mm/min). Após o ensaio, foi realizada a análise do padrão de fratura em estereomicroscópio (400X). Os dados obtidos foram submetidos à Análise de Variância para dados repetidos, seguido do teste de Tukey (?=5%). Verificamos que a densidade dos túbulos dentinários, em diferentes profundidades de molares permanentes, é inversamente proporcional a resistência de união de cimentos de ionômero de vidro de alta viscosidade. Foi ainda observado em todos os grupos que a resistência de união após 24 horas é maior do que em 12 meses, indicando degradação da interface adesiva ao longo do tempo.

The aim of this study was to evaluate the influence of dentin tubule density of different depths in the bond stability of two high viscous glass ionomer cements (GIC). Twenty (third) molars were assigned into 6 experimental groups, according to the depth of dentin - proximal, superficial or deep occlusal occlusal and the GICs - Fuji IX (GC Corp.) and Ketac (TM) Molar Easy Mix (3M / ESPE). Initially, the teeth were cut to obtain slices approximately 1 mm thick for approximal, superficial and deep occlusal surfaces. Then it was performed a topographical analysis of sections of different depths surfaces and laser confocal microscopy (100X) to obtain averages of the tubular density at each depth. Polyethylene cannulae were then positioned on the pre-treated dentin sections and filled with GIC. The specimens were stored in distilled water for 24 h and 12 months at 37°C were then subjected to microshear bonding test (0.5 mm / min). After the test, a fracture analysis pattern was performed in stereomicroscope (400X). The data were submitted to ANOVA for repeated measures followed by the Tukey test (? = 5%). We found that the density of dentinal tubules at different depths of permanent molars, is inversely proportional to the bond strength of high viscosity glass ionomer cements. It was observed in all groups which bond strength after 24 hours is higher than in 12 months, indicating degradation of the interface over time.

Comparación de la dureza superficial de diferentes tipos de materiales restauradores en premolares birradiculares, un estudio in vitro / Comparison of surface hardness of different types of restoratives materials in premolars birradiculares, a in vitro study

Objetivo: Evaluar y comparar la dureza superficial en restauraciones con ionómero de vidrio y de resina compuesta en cavidades clase I según Black en premolares birradiculares. Métodos: Se realizó un estudio descriptivo, comparativo in vitro donde se midió la dureza de dos tipos de materiales restauradores odontológicos, en cavidades clase I a dos distintas profundidades diseñadas en 32 premolares birradiculares. Distribuidos en 4 grupos con características distintas entre ellos, ya fuera por el material restaurador (ionómero de vidrio, resina compuesta) o por la profundidad de la cavidad (2-4 mm). Todas las muestras de cada grupo fueron sometidos a una fuerza vertical monitorizada a través del texturómetro EZ-S SHIMADZU hasta producir la fractura del material. Para evaluar la normalidad los datos obtenidos se sometieron a la prueba Shapiro Willk que rechazó la hipótesis nula. El análisis de los datos totales se realizó a través del test t de Student para muestras independientes. Resultados: Se evaluaron las durezas de la resina a 2 y 4 mm y el ionómero de vidrio a las mismas profundidades, encontrando una diferencia estadística a favor de la resina compuestas frente al ionómero de vidrio en ambas profundidades (p = 0,000001445 y p = 2,99E-9) y, en la comparación intragrupal, sólo diferencia significativa entre los dos grupos de resina a distinta profundidad (p = 0,016). Conclusión: Los órganos dentarios con cavidades de 4 mm de profundidad que fueron restaurados con resina Tetric N-Ceram evaluados presentan mayor dureza que los restaurados con resina Vitremer a 2 y 4 mm y que la misma resina a 2 mm de profundidad

Objective: To evaluate and compare the surface hardness on restorations with glass ionomer and composite resin in Class I cavities according to Black in birradiculares premolars. Methods: Descriptive, comparative In Vitro study, in which the hardness of two types of restorative materials was measured was performed in cavities class I at two different depths designed in 32 birradiculares premolars, which were divided into 4 groups with different including features, either by the restorative material (glass ionomer, composite resin) or the depth of the cavity (2-4 mm), all specimens from each group were subjected to a vertical force through the texturometer monitored to generate the fracture of the material. To assess normal data obtained were subjected to the test Shapiro Wilk to reject the null hypothesis, while the total data analysis was performed using Student's t-test for independent samples. Results: Evaluated the hardness of the resin at 2 and 4 mm and the glass ionomer to the same depths, showing a statistical difference in favor of the composite resin Vs glass ionomer both depths (p = 0.000001445 p = 2.99E-9) and intragroup comparison showing only significant difference between the two groups at different depths resin (p = 0.016). Conclusion: Of the materials tested in this comparative hardness study, the dental organs with cavities 4 mm depth were restored with Tetric N-Ceram have greater hardness than Vitremer 2 and 4 mm and the same resin to 2 mm depth

Acción de los agentes blanqueadores sobre materiales de restauración / Action of bleaching agents on restorative materials

El propósito del trabajo será analizar comparativamente los diversos efectos que producen sobre las restauraciones dentales agentes blanqueadores.El objetivo será valorar los cambios que experimentan en la superficie los materiales de restauración, sometidos a la acción de un agente blanqueador. La metodología utilizada será visualización microscópica electrónica de barrido ambiental. Los resultados obtenidos tendrán transferencia relevante a Insti-tuciones formadoras de recursos humanos en Salud Bucal, al campo profesional odontológico y a empresas o fabricantes para el mejoramiento de su producto...

Influence of heat and ultrasonic treatments on the setting and maturation of a glass-ionomer cement.

PURPOSE: To compare the effect of different treatments (heat capsule, ultrasound, and dual treatments) on the setting kinetics and maturation properties of a conventional GIC (EQUIA, GC) to that of standard setting. METHODS: The optimal durations of the heat and ultrasonic treatments were determined by monitoring changes in the COO-/COOH ratio, surface hardness, and temperature within the samples. The influence of optimal treatments on the maturation properties of the GIC (microhardness, and 3-point flexural strength) were assessed using GIC samples incubated in artificial saliva for 24 hours, 1 month, and 3 months. RESULTS: The optimal durations of the heat and ultrasonic treatments for accelerating setting were 5 minutes and 35 seconds, respectively. The dual treatment using the optimal conditions of the individual treatments further enhanced the setting kinetics. A temperature peak (49°C) within the GIC was detected during setting. Only the dual treatment increased the mechanical properties of the GIC after 24 hours compared to the control, while no significant difference was observed after 1 and 3 months.

Characterization of dental interfaces with electron tomography.

Understanding the interface between dental materials and tooth is critical in the prevention of secondary caries. Assessing this interface with high-resolution clarity has traditionally been challenging. This work highlights electron tomography, carried out in the transmission electron microscope, as a novel technique to obtain both three-dimensional and nanometer scaled information on dental materials in contact with dentin. In this study, commercial calcium aluminate and glass ionomer based luting agents in contact with human dentin were prepared for electron microscopy via focused ion beam milling. Imaging with high-angle annular dark field provided compositional contrast, and combined with tilting over large angular ranges, enabled the reconstruction of the three-dimensional interface between tissue and cement. The characteristics of the interface were observed with this extra dimensionality and superior resolution, providing evidence for the viability of this technique in interfacial studies of dental materials.

The effect of glass ionomer and adhesive cements on substance P expression in human dental pulp

OBJECTIVES: The purpose of this study was to quantify the effect of glass ionomer and adhesive cements on SP expression in healthy human dental pulp. Study DESIGN: Forty pulp samples were obtained from healthy premolars where extraction was indicated for orthodontic reasons. In thirty of these premolars a Class V cavity preparation was performed and teeth were equally divided in three groups: Experimental Group I: Glass Ionomer cement was placed in the cavity. Experimental Group II: Adhesive Cement was placed in the cavity. Positive control group: Class V cavities only. The remaining ten healthy premolars where extracted without treatment and served as a negative control group. All pulp samples were processed and SP was measured by radioimmunoassay. RESULTS: Greater SP expression was found in the adhesive cement group, followed by the glass ionomer and the positive control groups. The lower SP values were for the negative control group. ANOVA showed statistically significant differences between groups (p < 0.0001). Tukey HSD post hoc tests showed statistically significant differences in SP expression between negative control group and the 3 other groups (p < 0.01). Differences between the cavity-only group and the two experimental groups were also statistically significant (p < 0.05 and p < 0.01 respectively). There is also a statistically significant difference between the two experimental groups (p < 0.01). CONCLUSIONS: These findings suggest that adhesive cements provoke a greater SP expression when compared with glass ionomer

A preliminary clinical trial using flowable glass-ionomer cement asa liner in proximal-ART restorations: The operator effect

Objectives: This in vivo study was carried out to assess the influence of the operator experience on the survival rate of proximal-ART restorations using a two-layer technique to insert the glass-ionomer cement (GIC).Study Design: Forty five proximal cavities in primary molars were restored in a school setting according to the ART technique. The cavities were restored by two operators with Ketac Molar Easymix, and received a flowablelayer of GIC prior to a second GIC layer with a regular consistency. The operators had different clinical experiences with ART (no experience or two years of experience), but both completed a one-week training to perform the restorations and the GIC mixing in this study. Results: After a 12-month follow-up, 74% of the restorations survived; the main reason for failure was bulk fracture or total loss of the restoration. There was no operator influence (log-rank test p=0.2)Conclusion: The results encourage future well designed controlled clinical trials using the two-layer technique for insertion of GIC in proximal-ART restorations, after training the operators (AU)

Ex vivo study of bacterial coronal leakage in indirect pulp treatment

Objective: The aim of this study was to evaluate, ex vivo, bacterial coronal leakage with different antimicrobial agents applied to the dentine for indirect pulp treatment (IPT).Study Design: Sixty extracted teeth were prepared and randomly distributed into 5 groups (n=10): Group 1: no antimicrobial dentine treatment; group 2: 1% chlorhexidine (CHX)+1% thymol varnish (Cervitec®); group 3: 2% CHX solution; group 4: 40% CHX varnish (EC40™) and group 5: Clearfil™ Protect Bond (CPB). Ten teeth served as controls. The teeth were restored using a resin-modified glass ionomer cement (GIC) and then mounted in a two-chamber device. The coronal access was exposed to Streptococcus mutants for 45 days. The appearance of turbidity in the BHI broth of the lower chamber was considered as specimen leakage. Results: Survival analysis, determined by non parametric Kaplan-Meier and log-rank tests, showed that the best results were for groups EC40™+GIC and GIC alone; yet there were not statistically significant differences between them. All specimens of CPB+GIC and 2% CHX+GIC, leaked at 45 days. Conclusions: In IPT the use of GIC without pretreatment of the dentine and pretreatment with 40% CHX varnish resulted in a significant delay of bacterial coronal leakage (AU)

Comparison of a SiO(2)-CaO-ZnO-SrO glass polyalkenoate cement to commercial dental materials: glass structure and physical properties.

Glass polyalkenoate cements (GPCs) have previously been considered for orthopedic applications. A Zn-GPC (BT 101) was compared to commercial GPCs (Fuji IX and Ketac Molar) which have a setting chemistry analogous to BT 101. Handling properties (working, T (w) and setting, T (s) times) for BT 101 were shorter than the commercial GPCs. BT 101 also had a higher setting exotherm (S (x) -34 °C) than the commercial GPCs (29 °C). The maximum strengths for BT 101, Fuji IX, and Ketac Molar were 75, 238, and 216 MPa (compressive, σ (c)), and 34, 54, and 62 MPa (biaxial flexural strengths, σ (f)), respectively. The strengths of BT 101 are more suitable for spinal applications than commercial GPCs.