Physicochemical, Mechanical, and Esthetic Properties of the Composite Resin Manipulated with Glove Powder and Adhesive as a Modeling Liquid.

Composite resins with low flowability are usually handled and manipulated before insertion into the tooth preparation with gloved hands and/or using an instrument covered with a little amount of adhesive to facilitate modeling. We investigated if the modeling techniques (combined or not) affected physicochemical and esthetic properties of a composite resin. Specimens were fabricated and divided into groups according to the handling/modeling technique: Gloved-hands (composite was hand-manipulated with powdered latex gloves); Adhesive (adhesive was used in between the composite layers); Gloved-hands + Adhesive; Control (no adhesive and no touch with gloved-hands). The highest values for flexural strength (MPa), modulus of elasticity (GPa), and fracture toughness (MPa.m0.5) were obtained for Adhesive and Gloved-hands + Adhesive (p < 0.05); the lowest values were obtained for Control and Gloved-hands (p < 0.05). The Control group had the highest sorption. The Gloved-hands (p < 0.05) group had the highest solubility. Adhesive and Gloved-hands + Adhesive had a similar solubility (p > 0.05). The Control group (p < 0.05) had the lowest solubility. There was no statistical interaction between translucency vs. handling/modeling techniques and color stability vs. handling/modeling techniques. Adhesive as a modeling liquid protected the composite against sorption and solubility (if powdered gloves were used) and improved its physical/mechanical properties. Translucency and color stability were not correlated with modeling techniques.

Could Different Formulations of Grape Seed (Vitis vinifera) Influence the Physical Properties of Conventional Glass Ionomer Cement?

OBJECTIVE: The aim is to evaluate the ability of different formulations of grape seed (GS) to influence the physical properties of conventional glass ionomer cement (GIC). MATERIALS AND METHODS: Five groups were considered; Group I: Unmodified GIC (control), II: 3% v/v GS oil-modified GIC, III: 5% v/v GS oil-modified GIC, IV: 3% v/v ethanolic extract of GS (EEGS)-modified GIC and V: 5% v/v EEGS-modified GIC. Assessment parameters were; compressive strength, shear bond strength, surface roughness, water sorption and solubility and color difference. A representative specimen of each group was used for being analyzed by the Fourier transformation infrared spectroscopy. Analysis of variance was used to compare the results, followed by a Tukey post hoc test (P < 0.05). RESULTS: 3% v/v GS oil-modified GIC only exhibited a significant increase in its compressive strength and shear bond strength. Concurrently, there was a significant decrease in surface roughness, water sorption and solubility for 3% v/v GS oil-modified GIC group (P < 0.05). The least color change was for 3% v/v GS oil-modified GIC, which is a clinically acceptable change. CONCLUSIONS: 3% v/v GS oil-modified conventional GIC is an optimistic formulation of a restorative material with enhanced physical properties and agreeable esthetic.

Comparison of color stability, mechanical and chemical properties according to temporary crown resin type / 대한치과재료학회지

Objective of this study was to compare the color stability, mechanical and chemical properties of three different types of temporary crown resins. Commercially available powder-liquid (Group PL), light-cured (Group LC) and auto-mix syringe (Group AM) types' temporary crown resins were used as experimental groups for each of the evaluation. All the test groups were evaluated after 1 day and 7 days of immersion in various staining solutions. The colors of all groups before and after storage in the staining solutions were measured by a spectrophotometer based on CIE Lab system, and the color differences (ΔE(*)) thereby calculated. Micro hardness test was performed before water storage and aging after 7 days at 37 ℃. In addition, flexural strength, water sorption and solubility tests were performed according to international standard, ISO 10477. All experimental groups showed significant color change in staining solutions when compared to those stored in the control solution (distilled water) (p PL > LC (p<0.05). Water sorption and solubility increased in the following order: AM < PL < LC (p<0.05). The results of this study would provide useful information when choosing temporary crown resin types in various clinical situations.

Comparação in vitro da sorção e da solubilidade de quatro materiais restauradores provisórios em endodontia / In vitro comparison of the sorption and solubility properties of temporary restorative materials used in endodontics

Objetivo: Este estudo comparou as propriedades de sorção e solubilidade de materiais restauradores provisórios utilizados em endodontia. Material e método: Foram confeccionados 60 corpos de prova, divididos em quatro grupos: G1-IRM® (Dentsply), G2- Coltosol® (Coltene), G3- Riva Light Cure® (SDI), G4 Clip F® (Voco) e pesados após 24h em balança analítica de precisão. Após, foram imersas em água destilada por 12 dias e pesados novamente. Retornaram à estufa a 37 °C por 24h. Resultados: Apresentaram diferenças estatisticamente significativas entre os grupos para sorção e solubilidade. O grupo G4 apresentou menor grau de sorção com diferença estatística dos demais grupos (0,0000087). Os níveis de sorção, encontrados nos grupos G3 (0,0000313) e G1 (0,0000493), apresentam- -se estatisticamente semelhantes entre si e o G2 (0,0000573) foi estatisticamente semelhante ao G1(0,0000493). Quanto à solubilidade, G1 (0,0000107) apresentou o menor nível com diferença estatística em relação aos demais grupos. Os valores de solubilidade, em ordem crescente, foram verificados respectivamente nos grupos G4 (-0,0000213), G3 (-0,000064) e G2 (-0,0002693). Conclusões: 1. Materiais provisórios fotoativados apresentaram os menores resultados quanto à sorção de água; 2. Compostos à base de óxido de zinco e eugenol apresentaram o menor nível de solubilidade comparado com todos os outros materiais provisórios e 3 - compostos livres de eugenol de uso imediato obtiveram os maiores valores tanto de sorção quanto de solubilidade.

Objective: This study compared the sorption and solubility properties of temporary restorative materials used in endodontics. Material and method: 60 specimens were divided into four groups: G1-IRM® (Dentsply), G2-Coltosol® (Coltene), G3-Riva Light Cure® (SDI), G4 Clip F® ) and weighed after 24 hours in precision analytical balance scale. Afterwards, they were immersed in distilled water for 12 days and weighed again. They returned to the stove at 37 ° C for 24 hours. Results: There were statistically significant differences between the groups for sorption and solubility. The G4 group presented lower degree of sorption with statistical difference of the other groups (0.0000087). The sorption levels, found in groups G3 (0.0000313) and G1 (0.0000493), were statistically similar to each other and G2 (0.0000573) was statistically similar to G1 (0.0000493). Regarding solubility, G1 (0.0000107) presented the lowest level with statistical difference in relation to the other groups. The solubility values, in ascending order, were respectively verified in groups G4 (-0.0000213), G3 (-0.000064) and G2 (-0.0002693). Conclusion: 1. Temporary photoactivated materials presented the lowest results regarding sorption of water; 2. Compounds based on zinc oxide and eugenol showed the lowest level of solubility compared to all other provisional materials and 3. eugenolfree compounds of immediate use obtained the highest values of both sorption and solubility.

Evaluation of dental adhesive systems incorporating an antibacterial monomer eugenyl methacrylate (EgMA) for endodontic restorations.

OBJECTIVE: The purpose of this study was to incorporate EgMA, an antibacterial monomer into two commercial dental adhesive systems for their application in endodontic restoration with the aim to disinfect the root canal space before curing and to inhibit bacterial growth on their surfaces after being cured. METHODS: EgMA monomer was added at 20%wt. into the formulation of the single-component self-etch, Clearfil Universal Bond™ (CUB) and into the catalyst and the adhesive components of the total-etch Adper Scotchbond-multipurpose™ (SBMP) adhesive systems. The degree of conversion (DC) was calculated from FTIR spectra, glass transition temperature (Tg) determined by DSC, water sorption and solubility were measured gravimetrically, and surface free energy (SFE) via contact angle measurements. The bonding performance to coronal and middle root canal dentin was assessed through push-out bond strength after filling the canals with a composite core material and the surface integrity was observed using SEM and confocal laser scanning microscopy (CLSM). The standard agar diffusion test (ADT) was used to identify the sensitivity of three endodontically pathogenic bacteria, Enterococcus faecalis, Streptococcus mutans and Propionibacterium acnes to uncured EgMA modified adhesives. Multispecies biofilm model from these strains was grown on the disc surface of cured adhesives and investigated using quantitative microbial culture and CLSM with live/dead staining. MTT assay was also used to determine the cytotoxicity of these adhesives. RESULTS: The incorporation of EgMA lowered polymerization exotherm and enhanced the hydrophobic character of these adhesives, without changing the DC and Tg in comparison to the controls (without EgMA). The total push-out bond strengths of the EgMA-containing adhesives were not significantly different from those of the controls (p>0.05). The modification of self-etch adhesive system enhanced the bond strength in the middle region of the roots canal. SEM of debonded specimens and CLSM examination showed the integrity of the resin-dentin interfaces. For all three bacteria tested, the sizes of the inhibition zones produced by uncured EgMA modified adhesives were significantly greater (p<0.05) than those of the controls. The results of biofilm inhibition tests showed less CFU for total bacteria on bonding agents with EgMA compared to the control materials (p<0.05). The modification at 20% monomer concentration had no adverse effects on cytocompatibility of both adhesives tested. SIGNIFICANCE: The inclusion of EgMA endows dental adhesives with effective antibacterial effects without influencing their curing properties, bonding ability to root canal dentin, and cytotoxicity against human gingival fibroblasts, indicating the usefulness of their application in endodontic restorations.

The Comparison of Sorption and Solubility Behavior of Four Different Resin Luting Cements in Different Storage Media.

STATEMENT OF THE PROBLEM: Structural integrity and dimensional stability are the key factors that determine the clinical success and durability of luting cements in the oral cavity. Sorption and solubility of self-adhesive resin luting cements in food-simulating solutions has not been studied sufficiently. PURPOSE: This study aimed to compare the sorption and solubility of 2 conventional and 2 self-adhesive resin-based luting cements immersed in four different storage media. MATERIALS AND METHOD: A total of 32 disc-shaped specimens were prepared from each of four resin luting cements; seT (SDI), Panavia F (Kuraray), Clearfil SA Cement (Kuraray), and Choice 2 (Bisco). Eight specimens of each material were immersed in all tested solutions including n-heptane 97%, distilled water, apple juice, or Listerine mouth wash. Sorption and solubility were measured by weighing the specimens before and after immersion and desiccation. Data were analyzed by SPSS version 18, using two-way ANOVA and Tukey's HSD test with p≤ 0.05 set as the level of significance. RESULTS: There was a statistically significant interaction between the materials and solutions. The effect of media on the sorption and solubility was material-dependent. While seT showed the highest values of the sorption in almost all solutions, Choice 2 showed the least values of sorption and solubility. Immersion in apple juice caused more sorption than other solutions (p≤ 0.05). CONCLUSION: The sorption and solubility behavior of the studied cements were significantly affected by their composition and the storage media. The more hydrophobic materials with higher filler content like Choice 2 resin cement showed the least sorption and solubility. Due to their lower sorption and solubility, these types of resin-based luting cements are recommended to be used clinically.

Influence of a polymerizable eugenol derivative on the antibacterial activity and wettability of a resin composite for intracanal post cementation and core build-up restoration.

OBJECTIVES: Eugenol has been used in dentistry due to its ability to inhibit the growth of a range of microorganisms, including facultative anaerobes commonly isolated from infected root canals. The aim of this study was to evaluate the antibacterial activity of the experimental composites containing eugenyl methacrylate monomer (EgMA), a polymeric derivative of eugenol, against a range of oral bacteria, commonly associated with failure of coronal and endodontic restorations. In vitro composite behavior and wettability were also studied in conjunction with their antibacterial activity. METHODS: EgMA monomer (5 and 10% by weight) was added into BisGMA/TEGDMA resin based formulations with filler mixtures of hydroxyapatite (HA) and zirconium oxide ZrO2. The antibacterial activity of the experimental composites against Enterococcus faecalis, Streptococcus mutans and Propionibacterium acnes were evaluated by direct contact test and compared with composite formulation without inclusion of EgMA. To clarify the antibacterial mode of action, agar diffusion test (ADT) was also performed. Water sorption, solubility, diffusion coefficient, contact angle and surface free energy as complementary clinically relevant properties were determined. RESULTS: Water sorption and wettability studies showed reduction of water uptake and surface free energy values with increasing content of EgMA monomer, resulting in significant increase in the hydrophobicity of the composites. No inhibition zones were detected in any of the composites tested against the three bacteria employed as expected, due to the absence of any leachable antibacterial agent. The covalently anchored EgMA monomer with the composite surface exhibited an effective bacteriostatic activity by reducing the number of CFUs of the three species of bacteria tested with no significant dependence on the concentration of EgMA at 5 and 10% by weight. The surface antibacterial activity R of the experimental composites were different against the three tested species with values in the range 2.7-6.1 following the order E. faecalis

Use of dental adhesives as modeler liquid of resin composites.

OBJECTIVES: Resin adhesives (RA) have been applied between resin composite (RC) increments, but there is no consensus on the impact of this technique on the properties of the final restoration. This study evaluated the effect of the presence of RA between RC layers on physical properties, translucency and long-term color stability of the restorative material. METHODS: Scotchbond™ Multi-Purpose (bond, 3M ESPE) and Adper™ Single Bond 2 (3M ESPE) were used as RA, and Filtek™ Z350 (3M ESPE) as RC. Specimens containing RA were prepared by applying 3 layers of the adhesive between 4 increments of RC; adhesive-free specimens were also used (control). Tests of water sorption and solubility, mechanical performance (microtensile cohesive strength, flexural strength, and flexural modulus, after immediate and long-term water storage), and translucency and color stability (after immediate and 1, 7, 90, and 180 days of water or wine storage) were performed. Scanning electron microscopy (SEM) images were also taken from the fractured specimens (flexural strength test). Data were analyzed using ANOVA and Tukey test (p<0.05). RESULTS: Scotchbond (SBMP) showed lower water sorption and solubility than the control (p<0.001), and an overall similar (p≥0.198, immediate tests) or higher (p≤0.019, long-term tests) mechanical performance. SBMP exhibited a rougher cross-sectional surface compared to the other groups. Translucency remained unaltered after 180 days of storage (p≥0.313), except for single bond that had increased translucency with wine storage (p<0.045). After 180 days, all groups changed color (p≤0.002), although more intensively when immersed in wine. SIGNIFICANCE: The presence of RA within RC increments increased the physical stability of the material, being this effect more evident by using the hydrophobic unfilled adhesive resin (SBMP). This study is the first to show positive results from the use of resin adhesives as modeler liquid of resin composite, which is common in clinical practice.

Effect of Acidic Solutions on the Surface Degradation of a Micro-Hybrid Composite Resin

Composite resins may undergo wear by the action of chemical substances (e.g., saliva, alcohol, bacterial acids) of the oral environment, which may affect the material's structure and surface properties. This study evaluated the effect of acidic substances on the surface properties of a micro-hybrid composite resin (Filtek Z-250). Eighty specimens were prepared, and baseline hardness and surface roughness (KMN0 and Ra0, respectively) were measured. The specimens were subjected to sorption (SO) and solubility (SL) tests according to ISO 4049:2009, but using different storage solutions: deionized water; 75/25 vol% ethanol/water solution; lactic acid; propionic acid; and acetic acid. The acids were used in two concentrations: PA and 0.02 N. pH was measured for all solutions and final hardness (KMN1) and surface roughness (Ra1) were measured. Data were analyzed with paired t-tests and one-way ANOVA and Tukey's test (a=5%). All solutions decreased hardness and increased the Ra values, except for the specimens stored in water and 0.02 N lactic acid, which maintained the hardness. All solutions produced similar SO and SL phenomena, except for the 0.02 N lactic acid, which caused lower solubility than the other solutions. Ethanol showed the highest pH (6.6) and the 0.02 N lactic acid the lowest one (2.5). The solutions affected negatively the surface properties of the composite resin; in addition, an acidic pH did not seem to be a significant factor that intensifies the surface degradation phenomena.

Resinas compostas podem sofrer desgaste pela ação de substâncias químicas (saliva, álcool, ácidos bacterianos) presentes no ambiente oral, que podem afetar a estrutura e as propriedades superficiais do material. Assim, este estudo avaliou o efeito de substâncias ácidas nas propriedades superficiais de uma resina composta micro-híbrida (Filtek Z-250). Oitenta espécimes foram preparados e mensurados quanto à dureza e rugosidade superficial iniciais (KMN0 e Ra0, respectivamente). Os espécimes foram submetidos a testes de sorção (SO) e solubilidade (SL) de acordo com a ISO 4049:2009, porém usando diferentes soluções de armazenamento: água deionizada, solução etanol/água 75/25% em volume, ácido lático, ácido propiônico e ácido acético. Os ácidos foram utilizados em duas concentrações: PA e 0,02 N. O pH foi mensurado para todas as soluções e a dureza e rugosidade superficial finais (KMN1 e Ra1, respectivamente) foram mensuradas. Os dados foram analisados com testes t-pareado e ANOVA a um fator, e teste de Tukey (p<0,05). Todas as soluções reduziram a dureza e aumentaram os valores de Ra, exceto para os espécimes armazenados em água e ácido lático 0,02 N, que mantiveram a dureza. Todas as soluções produziram fenômenos de SO e SL similares, exceto o ácido lático 0,02 N, que causou menor solubilidade do que as outras soluções. Etanol mostrou o maior pH (6,6) e o ácido lático 0,02 N o menor deles (2,5). As soluções afetaram negativamente as propriedades superficiais da resina composta; além disso, um pH ácido não parece ser um fator significante para intensificar os fenômenos de degradação superficial.

Influence of various metal oxides on mechanical and physical properties of heat-cured polymethyl methacrylate denture base resins.

PURPOSE: To evaluate the effect of various metal oxides on impact strength (IS), fracture toughness (FT), water sorption (WSP) and solubility (WSL) of heat-cured acrylic resin. MATERIALS AND METHODS: Fifty acrylic resin specimens were fabricated for each test and divided into five groups. Group 1 was the control group and Group 2, 3, 4 and 5 (test groups) included a mixture of 1% TiO2 and 1% ZrO2, 2% Al2O3, 2% TiO2, and 2% ZrO2 by volume, respectively. Rectangular unnotched specimens (50 mm × 6.0 mm × 4.0 mm) were fabricated and droptower impact testing machine was used to determine IS. For FT, compact test specimens were fabricated and tests were done with a universal testing machine with a cross-head speed of 5 mm/min. For WSP and WSL, discshaped specimens were fabricated and tests were performed in accordance to ISO 1567. ANOVA and Kruskal-Wallis tests were used for statistical analyses. RESULTS: IS and FT values were significantly higher and WSP and WSL values were significantly lower in test groups than in control group (P<.05). Group 5 had significantly higher IS and FT values and significantly lower WSP values than other groups (P<.05) and provided 40% and 30% increase in IS and FT, respectively, compared to control group. Significantly lower WSL values were detected for Group 2 and 5 (P<.05). CONCLUSION: Modification of heat-cured acrylic resin with metal oxides, especially with ZrO2, may be useful in preventing denture fractures and undesirable physical changes resulting from oral fluids clinically.

Influence of various metal oxides on mechanical and physical properties of heat-cured polymethyl methacrylate denture base resins

PURPOSE: To evaluate the effect of various metal oxides on impact strength (IS), fracture toughness (FT), water sorption (WSP) and solubility (WSL) of heat-cured acrylic resin. MATERIALS AND METHODS: Fifty acrylic resin specimens were fabricated for each test and divided into five groups. Group 1 was the control group and Group 2, 3, 4 and 5 (test groups) included a mixture of 1% TiO2 and 1% ZrO2, 2% Al2O3, 2% TiO2, and 2% ZrO2 by volume, respectively. Rectangular unnotched specimens (50 mm x 6.0 mm x 4.0 mm) were fabricated and droptower impact testing machine was used to determine IS. For FT, compact test specimens were fabricated and tests were done with a universal testing machine with a cross-head speed of 5 mm/min. For WSP and WSL, discshaped specimens were fabricated and tests were performed in accordance to ISO 1567. ANOVA and Kruskal-Wallis tests were used for statistical analyses. RESULTS: IS and FT values were significantly higher and WSP and WSL values were significantly lower in test groups than in control group (P<.05). Group 5 had significantly higher IS and FT values and significantly lower WSP values than other groups (P<.05) and provided 40% and 30% increase in IS and FT, respectively, compared to control group. Significantly lower WSL values were detected for Group 2 and 5 (P<.05). CONCLUSION: Modification of heat-cured acrylic resin with metal oxides, especially with ZrO2, may be useful in preventing denture fractures and undesirable physical changes resulting from oral fluids clinically.

Efeito do tratamento térmico sobre a sorção e solubilidade, tenacidade à fratura e grau de conversão de compósitos restauradores diretos / Effect of post-curing heat cured treatment in sorption and solubility, fracture toughness and degree of conversion of direct composites

O tratamento térmico em compósitos restauradores diretos foi realizado a fim de verificar a influência sobre algumas propriedades, tais como a sorção, solubilidade, tenacidade à fratura e grau de conversão. Foram utilizados três compósitos: um nanoparticulado, um microhíbrido e um microparticulado. Duas fontes de luz (Halógena e LED) e dois períodos (48h e 28dias) de armazenagem, com exceção da solubilidade. O tratamento térmico foi realizado em estufa convencional (170o C por 5min), sendo metade dos corpos de prova (cps) tratados e a outra, apenas fotoativada.Para sorção e solubilidade, foram confeccionados 60 cps de acordo com os fatores analisados (n=5) em uma matriz metálica circular de dimensões 15 mm x1 mm. Para o cálculo da sorção e solubilidade, os cps foram pesados em uma Balança Analítica,inicialmente após a confecção do cp, 1hora, 24h, 48h, 7d, 14, 21 e 28d, a fim de estabelecer Massa Inicial (Mi) Massa absorvida (Ma) e Massa dessecada (Md). Para a tenacidade à fratura, foram confeccionados 240 cps de acordo com os fatores analisados (n=10) em uma matriz metálica de dimensões internas 25 mm x 5mm x 2,8 mm. O método utilizado foi o Single Edge Notch-Beam(SENB), com um entalhe de 2,3 mm posicionado no centro da matriz. Os cps eram levados à máquina universal para o ensaio de flexão e, após a ruptura, as superfícies de fratura eram analisadas no estereomicroscópio, para, em seguida, obter as imagens e calcular as dimensões do cps para inserir naequação da tenacidade à fratura.Já para o grau de conversão foram confeccionados 36 cps em uma matriz de acetato circular de 15 mm x 1 mm, posicionados entre duas lâminas microscópicas (n=3). O cálculo do grau de conversão foi determinado por espectroscopia no infravermelho (FTIR).Em geral, os estudos apresentaram uma influência significante do tratamento térmico...

The post-curing heat treatment in direct composite treatment was done to verify the influence on some properties like sorption, solubility, fracture toughness and the degree of conversion. During the referred study it was used three composites: nanoparticle, a microhybrid and a microfill. Two sources of light (Halogen and LED) and two periods (48 hours and 28 days) for each one, but not to solubility. The postcuringwas done in dry heat sterilizer of 170º C for five minutes for, half of the test samples (TS) were treated and the other half were only photoactivated. It was made 60 TS to sorption and solubility according to the analyzed factors (n=5) in a 15mm x 1mm round metal matrix. To calculate sorption and solubility the TS were weighted in a analytical balance, right after the beginning of the production in 1 hour, 24 hours, 7days, 14 days, 21 days and 28 days respectively in order to establish the initial absorbed mass (Mi), the absorbed mass (Ma) and the desiccated mass (Md ). It was produced 240 TS to the fracture toughness according to factors (n=10) in a 25mm x 5mm x 2,8mm in metallic matrix. The Single Edge Notch-Beam (SENB), was the used method during this study with a notch of 2,3mm placed in the center of the matrix. The TS were taken to a universal machine to flexural test so after the rupture referred surface fractures were analyzed in a stereomicroscope and then it was possible to get the images to calculate the size of the TS to insert the calculus of the fracture toughness...