Analysis of sealing vs tensile bond strength of eight adheisve restorative material systems

Purpose: Using a simulated perfusion system, the intent was to determine: 1) the sealing ability of eight restorative materials (five composite resins and three compomers) used together with their corresponding dentin bonding systems, 2) their tensile bond strength, and 3) the correlation (if any) between both parameters. Materials and Methods: Permeability in crown segments from sound human third molars (n = 140) subjected to simulated perfusion (32 cm of distilled water) was measured before and after restoring with each material, and the percentage of decrease in permeability ((PPD) was recorded. Specimens were tater subjected to tensile tests to determine the tensile bond strength (TBS) of the interface. Finally, parameters were analyzed for correlation. Results: For the eight adhesive systems, the percentage of reduction in permeability was relatively hlgh [mean in %, (SD)]: F2000 93.6 (5.7),S B188.6 (11.31,S SC 86.0 (5.7), PB20 81.1 (15.9)C,O M 77.5 (10.8), OPTS 75.3 (20.6)D,Y R 73.7 (12.7)S,S PR 65.5 (19.8)T.B S values were relatively low [mean (SD)], in MPa: F2000 1.8 (0.71, SB1 4.9 (1.4)S,S C 2.6 (1.4), PB20 4.3 (1.21,C OM 2.4 {1.1),O PTS 4.5 (1.7)D,Y R L6 (0.6), SSPR.4.2 (1.5). We could not demonstrate any statistically significant correlation between both parameters for these results (maximum significance [F20001: r = 0.39, p = 0.206). Conclusion: No material completely ceased to filtrate through the interface. The low TBS values were probably due to the large size of adhesive areas. No significant correlation was found between PPD and TBS for the materials tested. There was a statistically significant relationship (r2 = 0.063, p = 0.018) between TBS and TEA (total bonded area), described by the equation TBS = 5.9 - 0.03'TBA

Estudio in vitro de las variaciones de la permeabilidad dentinaria tras la obturación mediante cementos de vidrio ionómero fotopolimerizables

La presencia constante de fluido dentinario en la superficie adhesiva condiciona la unión diente/material restaurador. Por otra parte, al sellarse la interfase diente/material el comportamiento de dicho fluido dentinario debería cambiar. Esto es lo que hemos estudiado en nuestro trabajo, para tres cementos de vidrio ionómero fotopolimeralizables (Photac Fil, Viltremen y Dyract), utilizando un sistema derivado del descrito por Derkson, Pashley y Derkson, que mide, en microlitros, las pérdidas que se producen a través de la dentina cortada de coronas de molares humanos extraídos. El área de pérdidas se mide mediante análisis computarizado de imágenes y se utiliza como patrón el comportamiento de casos sin restaurar, comparándolos con casos restaurados con los tres tipos de materiales citados. Los resultados parecen indicar que no se produce la detención esperada del movimiento hacia fuera del fluido, lo que nos sugiere nuevas modificaciones del sistema de medición, como la utilización de discos de dentina, y de la preparación de los especímenes.// The constant presence of dentinary fluid in the adhesive surface conditions the tooth/restorative material interaction. In the other hand, when the interfase is properly sealed, the behaviour of that dentinary fluid should change. This possible change is studied in this work, for three light-cured glass ionomer cements (Photac Fil, Vitremen and Dyract), using a system derived of the one described by Derkson, Pashley and Derkson, able to measure, in microliters, the dentinary fluid outward movement through the cut dentin of crowns of human molars. The exposed area is measured by computerized image analysis, The loss of unrestored specimens is used as a control and compared with three types of above said materials. Results denote that expected halt of outward movement of the fluid does not take place. This suggests us further modifications of the system, as the utilization of dentin disc and different specimen holders

Sealing and dentin bond strength of adhesive systems in selected areas of perfused teeth

Objectives: (1) Test the sealing capacity and tensile strength of various adhesive systems: Scotch Bond 1 (Single Bond in USA)(SB1) + Z100, Syntac Sprint (SYN) + Tetric Ceram, Prime and Bond 2.1 (PB21) + TPH Spectrum, F2000 (Adhesive 1 Compomer) (F2000) and Optibond Solo (OPT) + Prodigy, to perfused teeth (30 cm distilled H2O), in select areas. (2) Determine the relationship between sealing ability and size of adhesive area (BA) with tensile strength (TS). Methods: Segments of human third molars (n=67) sealed with amalgam on their coronal side were connected to a perfusion system (30 cm distilled H2O), to measure the basal permeability. Access cavities were drilled through the amalgam to expose dentin (area range: 8.7±20.8 mm2) and measure the permeability of that area. Cavities were sealed with one of the test materials and permeability measured prior to tensile testing. The percentage of decrease in permeability (PPD) that occurred with the different combinations of materials was also measured. Results. Tensile strength: there were no statistically signi®cant differences among groups. Permeability: ANOVA showed that there were statistically signi®cant differences in the mean % decrease in permeability (PPD) among groups (p= 0:018): Student-Newman-Keuls test (p=0:05) detected that the mean PPD of F2000 ranked statistically higher than that of SB1. Relationship among variables: a linear correlation was found defined by the formula TS= 7:47+ 0:008·PPD - 0:23·BA; with a significance of the model p=0.0097. Significance: None of the materials studied reduced permeability up to 100%. They all produced low tensile bond strengths (maximum mean value of groups: 5.51 MPa (OPT))

Permeabilidad dentinaria. Relación entre los distintos parámetros que la definen

Mediante un sistema simulado de perfusión, se mide la permeabilidad de discos de dentina. Se estudia la relación entre el área y el espesor de la dentina a través de la cual se perfunde, y la magnitud del gasto (volúmen/tiempo). Debido principalmente a la variabilidad anatómica, no es posible establecer una relación estadísticamente significativa entre dichos parámetros. El radio efectivo medio calculado (p<0.001) de los túbulos varía entre 0,13±0.024 µm y 0.08 ± 0.0015 µm, supuestas unas densidades tubulares respectivas de 20.000 y 50.000 túbulos/mm². // We measure of permeability of dentin by means of a simulated perfusion system. We study the relation between the area, the thickness and the volume/time magnitude. We could not establish an statistical relationship between the cited factors, because of anatomical variations. The median effective radius calculated (p<0.001) was between 0.13±0.024 µm and 0.08±0.0015 µm, suposed a density of 20.000 or 50.000 tubuli/mm², respectively.Depto. de Odontología Conservadora y PrótesisFac. de OdontologíaTRUEpu

Sealing and Dentin Bond Strengths of Adhesive Systems

The objectives of this research were (1) to analyze the variations of the permeability of dentin after restoration with two polyacid-modified resin composites (Compoglass, Dyract) and four single-bottle adhesives (Prime & BOnd 2.0, Syntac Single Component, OptiBond Solo, and Single Bond -Scotch Bond 1 in Europe- immediately (approximately 1 hour) after insertion. A perfusion system with distilled water was used at a pressure of 32.5 cm of water; (2) to study the bond strength of their interfaces; and (3) to find the correlation, if any, between both parameters. None of the materials used produces a complete cessation in fluid filtration. Tensile strengths were very low (maximum: P&B=3.96MPa) probably because of the very large bonding surfaces used (mean bonded surface area = 88.8mm²). No significant correlation was found between tensile bond strength and the sealing ability for any material

Inverse Relationship between Tensile Bond Strength and Dimensions of Bonded Area

It is a known fact that there is a relationship between magnitude of bonded area and laboratory tensile test results. This relationship has been described for a range of areas between 1 and 100 mm2, in extracted, nonperfused teeth. The aim of this study is to test this relationship in perfused teeth, with bonden areas ranging from 0.7 to 110.9 mm2. Dentin of 92 sound third human molars was exposed and perfused, and three groups of bonden areas (BA) were delimited: small (0.69-1.89 mm2), medium (8.66-19.54 mm2), and large (58.91-110.86 mm2). Tensile bond strength (TBS) of three adhesive restorative systems was found. The best nonlinear curve estimation was searched (SPSS 9.0) between TBS and BA, for each and all materials. The best estimation was, for all materials, TBS = 4.17 + 10.35/BA (p minor to 0.0001

Medida de la conductancia hidráulica en terceros molares humanos. Un estudio in vitro

La dificultad de realizar determinados estudios sobre materiales odontológicos in vivo hace necesario el desarrollo de sistemas que reproduzcan las condiciones clínicas reales. En este trabajo se aplica un sistema que permite trabajar con un diente con una presión hidrostática intrapulpar simulada de 32,5 cm de agua, similar a la humana, y una superficie dentinaria expuesta, cuantificada mediante análisis de imágenes, a través de la cual se produce la filtración. Hemos medido la conductancia hidráulica de nueve terceros molares intactos, obteniendo un patrón de la misma, que se puede describir con la fórmula Ch=0.002601· t+0.013619, siendo h la conductancia hidráulica, en ml/mm2, y t el tiempo en minutos. La comparación, en futuros estudios, de este patrón con la filtración que se produzca tras la obturación con diferentes materiales, nos permitirá conocer la capacidad de sellado de los mismos, y así valorar si la presencia de fluido en la superficie de la dentina altera la adhesión de los materiales restauradores. // The trouble of carring out "in vitro" studies with dental materials, makes it necessary to develop systems reproducing the actual clinical conditions. In this study a system is used wich allows working with a tooth with a simulated intrapulpal hydrostatic pressure of 32,5 cm of water, as "in vitro" to human, and an exposed dentinal surface quantified by image analysis, through which filtration occurs. Hydraulic conductance of nine intact third molars has been measured, obtaining a pattern that can be described by the formula Ch=0.002601· t+0.013619, being Ch the hydraulic conductance given in ml/mm2m and t time in minutes. Comparison, in future studies, of this pattern with the filtration that occurs after obturation with different materials will allow us to estimate their sealing capacity, and therefore to know if the fluid presence in the dentin surface may alter the restorating materials adherence

Cementado de inlays de composite II

Estudio comparativo entre la resistencia a la tracción de incrustaciones simuladas de resina compuesta, cementadas mediante tres métodos: ácido fosfórico y bonding (grupo I), imprimación con un disolvente sin resina de unión (grupo II) o con ella (grupo III). Los resultados indican que, con una probabilidad de error menor del 5%, es mejor aplicar uno cualquiera de los imprimadores probados. Comparative study of traction resistance of simulated composited resin inlays between three groups treated with phosphoric acid and bonding (group I), priming with a solvent (group II) and with a solvent with bonding (group III). Results indicated that, with a probability of error lesser than 5%, is more effective applying any of the primers tested

Un método experimental para el estudio de la permeabilidad dentinaria

Depto. de Odontología Conservadora y PrótesisFac. de OdontologíaTRUEpu

El sellado de la amalgama adherida "versus" otros materiales de restauración

Introducción: estudio comparativo in vitro de la capacidad de sellado entre restauraciones de amalgama adherida, de resina compuesta y resina compuesta modificada con vidrio ionomero. Material y método: se usaron 175 molares humanos conectados a un sistema de presión simulada (32 cm de agua destilada), determinándose la consductancia hidráulica de cada espécimen tras ser obturados con cada uno de los distintos materiales de estudio. Resultados: los resultados evidencian que la condustancia de los especímenes restaurados con amalgama adherida es menor que la obtenida con el resto de los materiales, sobre todo con F2000 y Dyract. Conclusiones: las restauraciones de amalgama adherida reducen la permeabilidad en mayor grado que los materiales a base de resina compuesta modificada, aunque ninguno de los materiales detiene por completo la filtración. // Introduction: the present article is a comparative in vitro study of the sealing ability of bonded amalgams versus glass-ionomer modified composite resins and composite resin restorations. Materials and methods: 175 human molars were connected to a simulated pressure system (32 cm of distilled water). The hydraulic conductance of each sample was determines after being resored with each one of the different materials tested. Results: results show less residual hydraulic conductance in samples restored with bonden amalgam than in samples with the rest of materials tested, specially with F2000 and Dyract. Conclusions: in those samples restored with bonden amalgam permeability is reduced to a higher extend than in samples restored with resin modified glass-ionomers. None of material stopped filtration through dentin completely