Surface gloss, gloss retention, and color stability of 2 nano-filled universal resin composites.

Objectives: This study compared the surface gloss (SG), gloss retention (GR), and color stability (CS) of 2 universal resin composites after chemical (CA) and mechanical (MA) aging. Materials and Methods: Twenty disc-shaped samples of G-ænial A´Chord (GC-Europe) and Filtek Universal (3M-ESPE) were polished with sequential abrasive papers. For CA, specimens were stored in 1 mL of 75% ethanol for 15 days at 37°C, and readings (SG, GR, and CS) were obtained at baseline and 5, 10, and 15 days. For MA, specimens were subjected to 10,750 simulated brushing cycles. SG and CS were evaluated after every 3,583 cycles. SG was measured with a glossmeter (geometrical configuration: 60°), and values were expressed in gloss units. Color was measured with a spectrophotometer using the CIE-L*a*b* color system. The Student's t-test, 1-way analysis of variance, and Scheffé test were used for statistical analysis (α = 0.05). Results: G-ænial presented significantly higher SG values than Filtek (p = 0.02), with GR reductions of 5.2% (CA) and 5.3% (MA) for G-ænial and 7.6% (CA) and 7.2% (MA) for Filtek. The aging protocol had no statistically significant effect on SG or GR (p = 0.25) from baseline to the final readings. G-ænial-MA presented the lowest color difference (∆E = 1.8), and G-ænial-CA and Filtek-CA had the largest changes (∆E = 8.6 and ∆E = 11.8, respectively). Conclusion: G-ænial presented higher SG values and better CS. Both restorative materials demonstrated acceptable GR and CS. Aging protocols impacted these properties negatively.

Resistencia a la compresión de Biodentine®: mezcla manual vs. Mecánica / Compressive strength of Biodentine®: mechanical vs. manual mix

INTRODUCCIÓN: La incorporación de innovaciones tecnológicas en determinados materiales dentales, especialmente aquellos que requieren de aparatología específica para su uso y/o cuya pre-dosificación implica el descarte de una porción de su contenido, está condicionada por la relación costo-beneficio del producto. Según las instrucciones del fabricante, las cápsulas del silicato tricálcico Biodentine® (Septodont) deben activarse mediante el uso de mezcladores mecánicos luego de adicionar las proporciones exactas del líquido ad-hoc, utilizando la totalidad de cada cápsula de polvo y su respectiva ampolla del líquido, con un excedente de material considerable, según su indicación. Si bien es posible realizar la mezcla del cemento en forma manual prescindiendo de un amalgamador, una modificación en las recomendaciones del fabricante podría alterar las propiedades del material. OBJETIVO: Determinar si existen diferencias en la resistencia compresiva de Biodentine® según el método de mezcla utilizado: con activación mecánica y con mezcla manual. MATERIALES Y METODOS: Se confeccionaron probetas cilíndricas de 6 mm de alto por 4 mm de diámetro (n=6) para los dos grupos de estudio A) Biodentine® / Mezcla manual y B) Biodentine® / Mezcla mecánica. Las muestras fueron sometidas a la aplicación de una fuerza continua en máquina universal de ensayos Digimess RS-8000-5 a una velocidad de carrera de 1 mm/min hasta su ruptura. Se compararon los valores obtenidos entre los grupos mediante test de Student, determinando diferencias significativas para valores de p>0,05. RESULTADOS: Los valores medios obtenidos y su desviación estándar fueron A) 52.6 (16.3) MPa y B) 65.7 (30.6) MPa respectivamente. La distribución de valores de resistencia a la compresión según el grupo de estudio fue levemente superior en el grupo B, aunque las diferencias no fueron significativas (p=3,77). CONCLUSIONES: La mezcla manual no disminuye significativamente la resistencia a la compresión de Biodentine® en comparación al cemento mezclado mecánicamente.

INTRODUCTION: Economic circumstances may create difficulties in access to certain dental materials, especially those that a part of their content has to be disposed after mixing. According to the manufacturers´ instructions, capsules of tri-calcium silicate Biodentine® (Septodont) ought to be activated using a mechanical mixer after addition of the liquid accordingly. The whole content of a capsule is then used before the setting of the material. Aim: To compare the effect of the mixing mode on the compressive strength of Biodentine®, mixed manually and using a mechanical mixer. OBJECTIVE: To compare the effect of the mixing mode on the compressive strength of Biodentine®, mixed manually and using a mechanical mixer. MATERIALS AND METHODS Two groups were defined, A) Biodentine® / Manual mix and B) Biodentine® / Mechanical mix, with n = 6 cylindric specimens each of 6 mm height and 4 mm diameter. Samples were tested using a universal testing machine Digimess RS-8000-5 at a crosshead speed of 1 mm/min until fracture. Obtained values were compared using the Student-t test with a significance of p>0,05. RESULTS: Mean values were A) 52.6 (16.3) MPa and B) 65.7 (30.6) MPa respectively, finding no significant differences between the two groups (p=3,77). CONCLUSION: Compressive strength is not affected in Biodentine® when mixed manually compared to mechanical mixing.

Randomized Controlled Trial of Class II ART High-viscosity Glass-ionomer Cement and Conventional Resin-composite restorations in Permanent Dentition: Two-year Survival.

Purpose: To compare the 2-year cumulative survival rates of class II restorations made according to Atraumatic Restorative Treatment (ART) with axial grooves and the high-viscosity glass-ionomer cement (HVGIC) Equia Fil (GC) and the conventional method using the resin composite Filtek Z250 (3M Oral Care). Materials and Methods: A parallel-group study design and a stratified randomization process (DMFS count and cavity size) were applied. Restorations were evaluated according to the ART restoration and USPHS criteria. Data were statistically analyzed using the proportional hazard rate regression model with frailty correction. Results: 272 class II restorations were placed in 131 people (mean age 26.2 years) by two dentists. The dropout rate of restorations was 2.6%. According to ART restoration and USPHS criteria, the 2-year cumulative survival rates of class II ART/HVGIC restorations were 96.2% and 97.0%, respectively, and 97.8% and 98.5%, respectively, for the conventional class II resin-composite restorations. No differences were observed in the cumulative survival rates between the two treatment groups at 2 years (ART criteria: p=0.26; USPHS criteria p=0.23). Conclusion: HVGIC Equia Fil used in the ART method with axial grooves and Filtek Z250 in the conventional method provided high survival rates for restoring class II cavities over 2 years.

Nanotecnología aplicada a la optimización de cementos de ionómero vítreo para restauración: Presentación y discusión de un caso / Nanotechnology applied to optimize Restorative Glass Ionomer Cements: Discussion of one case

La decisión de eliminar la amalgama dental como material de restauración por parte de asociaciones odontológicas de referencia internacional ha motivado la creación de una agenda de investigación y desarrollo para encontrar el sustituto más adecuado. En este marco, los cementos de ionómero vítreo se posicionan como uno de los materiales con mejores características para cumplir la función de restauración. El aporte de la nanotecnología ha colaborado para mejorar propiedades ópticas y mecánicas de este grupo de materiales. Se presenta el seguimiento clínico por 6 años luego del reemplazo de cavidades oclusales simples de amalgama por cementos de ionómero vítreo de alta viscosidad en molares permanentes inferiores, con resultados aceptables según dos criterios de evaluación. (AU)

Decision of phasing out amalgam by referential international dental associations has motivated the creation of a research and development agenda in order to find out the best substitute for this metal alloy. In this scenario, glass ionomer cements are suggested as one of the most suitable restorative materials for this task. Nanotechnology has contributed to improve their optical and mechanical properties. The present article discusses a case that had been followed up for 6 years after old amalgams of occlusal cavities were replaced by a restorative high viscosity glass ionomer cement with an acceptable performance according to two assessment criteria. (AU)

Three-year survival of ART high-viscosity glass-ionomer and resin composite restorations in people with disability.

OBJECTIVES: To assess the 3-year cumulative survival rate of atraumatic restorative treatment (ART) and conventional resin composite restorations (CRT) placed in persons with disability. MATERIALS AND METHODS: Patients referred for restorative care to the Haemophilia Foundation special care service were treated by one of two specialists. Patients and/or caregivers were provided with written and verbal information regarding treatment options and selected the alternative they preferred. Treatment was provided as selected unless this option proved clinically unfeasible when an alternative technique was proposed. The treatment protocols were ART (hand instruments/high-viscosity glass-ionomer) in the clinic or CRT (rotary instrumentation/resin composite) in the clinic or under general anaesthesia (GA). After 6, 12, 24 and 36 months, two independent, trained and calibrated examiners evaluated restoration survival using established ART codes. The proportional hazard model with frailty corrections gave survival estimates over 3 years. RESULTS: Sixty-six patients (13.6 ± 7.8 years) with 16 different disability profiles participated. CRT in the clinic proved feasible for five patients (13%), and 14 patients received CRT under GA (21%). ART was used for 47 patients (71.2%). Altogether, 298 dentine carious lesions were restored in primary and permanent teeth (182 ART; 116 CRT). The 3-year cumulative survival rates and jackknife standard errors for the 182 ART and 116 CRT restorations were 94.8 ± 2.1 and 82.8 ± 5.3%, respectively (p = 0.01). CONCLUSIONS: The 3-year follow-up results confirm that ART is an effective treatment protocol. CLINICAL RELEVANCE: Patients with disability, many of whom have difficulty coping with CRT, may benefit from the ART approach.

One year survival of ART and conventional restorations in patients with disability.

BACKGROUND: Providing restorative treatment for persons with disability may be challenging and has been related to the patient's ability to cope with the anxiety engendered by treatment and to cooperate fully with the demands of the clinical situation. The aim of the present study was to assess the survival rate of ART restorations compared to conventional restorations in people with disability referred for special care dentistry. METHODS: Three treatment protocols were distinguished: ART (hand instruments/high-viscosity glass-ionomer); conventional restorative treatment (rotary instrumentation/resin composite) in the clinic (CRT/clinic) and under general anaesthesia (CRT/GA). Patients were referred for restorative care to a special care centre and treated by one of two specialists. Patients and/or their caregivers were provided with written and verbal information regarding the proposed techniques, and selected the type of treatment they were to receive. Treatment was provided as selected but if this option proved clinically unfeasible one of the alternative techniques was subsequently proposed. Evaluation of restoration survival was performed by two independent trained and calibrated examiners using established ART restoration assessment codes at 6 months and 12 months. The Proportional Hazard model with frailty corrections was applied to calculate survival estimates over a one year period. RESULTS: 66 patients (13.6 ± 7.8 years) with 16 different medical disorders participated. CRT/clinic proved feasible for 5 patients (7.5%), the ART approach for 47 patients (71.2%), and 14 patients received CRT/GA (21.2%). In all, 298 dentine carious lesions were restored in primary and permanent teeth, 182 (ART), 21 (CRT/clinic) and 95 (CRT/GA). The 1-year survival rates and jackknife standard error of ART and CRT restorations were 97.8 ± 1.0% and 90.5 ± 3.2%, respectively (p = 0.01). CONCLUSIONS: These short-term results indicate that ART appears to be an effective treatment protocol for treating patients with disability restoratively, many of whom have difficulty coping with the conventional restorative treatment. TRIAL REGISTRATION NUMBER: Netherlands Trial Registration: NTR 4400.

Mechanical performance of encapsulated restorative glass-ionomer cements for use with Atraumatic Restorative Treatment (ART).

UNLABELLED: The Atraumatic Restorative Treatment (ART) approach was suggested to be a suitable method to treat enamel and dentine carious lesions in patients with disabilities. The use of a restorative glass-ionomer with optimal mechanical properties is, therefore, very important. OBJECTIVE: To test the null-hypotheses that no difference in diametral tensile, compressive and flexural strengths exists between: (1) The EQUIA system and (2) The Chemfil Rock (encapsulated glass-ionomers; test materials) and the Fuji 9 Gold Label and the Ketac Molar Easymix (hand-mixed conventional glass-ionomers; control materials); (3) The EQUIA system and Chemfil Rock. MATERIAL AND METHODS: Specimens for testing flexural (n = 240) and diametral tensile (n=80) strengths were prepared according to standardized specifications; the compressive strength (n=80) was measured using a tooth-model of a class II ART restoration. ANOVA and Tukey B tests were used to test for significant differences between dependent and independent variables. RESULTS: The EQUIA system and Chemfil Rock had significantly higher mean scores for all the three strength variables than the Fuji 9 Gold Label and Ketac Molar Easymix (α=0.05). The EQUIA system had significant higher mean scores for diametral tensile and flexural strengths than the Chemfil Rock (α=0.05). CONCLUSION: The two encapsulated high-viscosity glass-ionomers had significantly higher test values for diametral tensile, flexural and compressive strengths than the commonly used hand-mixed high-viscosity glass-ionomers.

Biaxial flexural strength of high-viscosity glass-ionomer cements heat-cured with an LED lamp during setting.

Adding heat to glass ionomers during setting might improve mechanical properties. The aim was to compare the biaxial flexural strength (BFS) between and within four glass ionomers, by time of exposure to a high-intensity LED light-curing unit. Materials and methods. Samples of Fuji 9 Gold Label, Ketac Molar Easymix, ChemFil Rock, and the EQUIA system were divided into three treatment groups (n = 30): without heating (Group 1), heated with LED lamp of 1400 mW/cm(2) for 30 s while setting (Group 2), and heated with LED lamp of 1400 mW/cm(2) for 60 s while setting (Group 3). Samples were stored for 48 hours in distilled water at 37°C until tested. BFS was tested, using a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed, using ANOVA test with the Bonferroni correction (α = 0.05). Heating the glass-ionomer cements with an LED curing light of 1400 mW/cm(2) during setting for 30 s increased the BFS value of all GICs. No statistically significant difference in mean BFS scores was found between the EQUIA system and ChemFil Rock at 30 s and 60 s. The mean BFS value was statistically significantly higher for the EQUIA system and ChemFil Rock than for Fuji 9 Gold Label and Ketac Molar Easymix at all exposure times.

Mechanical performance of encapsulated restorative glass-ionomer cements for use with Atraumatic Restorative Treatment (ART)

The Atraumatic Restorative Treatment (ART) approach was suggested to be a suitable method to treat enamel and dentine carious lesions in patients with disabilities. The use of a restorative glass-ionomer with optimal mechanical properties is, therefore, very important. Objective To test the null-hypotheses that no difference in diametral tensile, compressive and flexural strengths exists between: (1) The EQUIA system and (2) The Chemfil Rock (encapsulated glass-ionomers; test materials) and the Fuji 9 Gold Label and the Ketac Molar Easymix (hand-mixed conventional glass-ionomers; control materials); (3) The EQUIA system and Chemfil Rock. Material and Methods Specimens for testing flexural (n = 240) and diametral tensile (n=80) strengths were prepared according to standardized specifications; the compressive strength (n=80) was measured using a tooth-model of a class II ART restoration. ANOVA and Tukey B tests were used to test for significant differences between dependent and independent variables. Results The EQUIA system and Chemfil Rock had significantly higher mean scores for all the three strength variables than the Fuji 9 Gold Label and Ketac Molar Easymix (α=0.05). The EQUIA system had significant higher mean scores for diametral tensile and flexural strengths than the Chemfil Rock (α=0.05). Conclusion The two encapsulated high-viscosity glass-ionomers had significantly higher test values for diametral tensile, flexural and compressive strengths than the commonly used hand-mixed high-viscosity glass-ionomers. .