Eficacia del cementado indirecto / Indirect bonding efficiency

La aparición de aparatología preadjustada ha colaborado en la efectividad de los tratamientos de ortodoncia, pero para que la expresión de esta aparatología se logre, es necesario una correcta colocación de los brackets y la permanencia de estos en boca durante todo el tratamiento. La precisión en la colocación mejora con la técnica de cementado indirecta, ya que permite el acceso a las zonas posteriores, a lugares donde se ve disminuida la visión y además disminuye la condensación de aliento y contaminación salival. Si bien esta técnica requiere tiempo extra de laboratorio, es más rápida en la etapa clínica (AU)

Resistencia al cizallamiento utilizando adhesivo de grabado total y autograbante con y sin hipoclorito de sodio en dentina / Shear strength using total and self etching adhesive with and without sodium hypochlorite in dentin

Es un estudio de investigación cuantitativo donde el objetivo fue determinar la resistencia al cizallamiento utilizando adhesivo de grabado total y autograbante, introduciendo la desproteinización con NaOCl al 5.25 por ciento en dentina y comparar sus valores de resistencia. El estudio se realizó en 31 molares seccionados mesiodistalmente y vestibulo lingual, obteniendo 124 especímenes, se suspendieron en acrílico, pulieron y colocaron en refrigeración a 36 oC durante 48 horas; fueron clasificados en grupos A: Prime & Bond NT, B: NaOCl + Prime & Bond NT, C: NaOCl + Xeno® IV y D: Xeno® IV; se fotoactivó un cilindro de resina compuesta ESTHET-X HD de Dentsply, se mantuvo por 24 horas en horno Felisa con 100 por ciento de humedad, finalmente se probaron en la máquina INSTRON a una velocidad de 1 m/min. Se obtuvieron los siguientes promedios, grupos: A: 6.26, B: 7.71, C: 12.03 y D: 15.06 MPa. Para el grupo C y D que pertenecen al grupo autograbante, fueron estadísticamente significativos para el sustrato dentinal. NaOCl no mostró significancia entre los grupos.

It is a quantitative research where the objective was to determinethe shear strength using total and self etching adhesive, introducing de proteinization with 5.25% NaOCl in dentin and comparing its resistance values. The study was performed on 31 mesiodistally andbuccololingual sectioned molars, obtaining 124 specimens, suspended in acrylic, polished and placed in refrigeration at 36 oC for 48 hours;Were classified into groups A: Prime & Bond NT, B: NaOCl + Prime& Bond NT, C: NaOCl + Xeno® IV and D: Xeno® IV; A: DentsplyESTHET-X HD composite resin cylinder was photoactivated, kept for24 hours in a Felisa oven with 100% humidity, finally tested on theINSTRON machine at a speed of 1 mm/min. The following averageswere obtained, groups: A: 6.26, B: 7.71, C: 12.03 and D: 15.06 MPa.For group C and D belonging to the self-etching group, they werestatistically significant for the dentinal substrate. NaOCl, showed nosignificance between the groups.

Can We Improve the Laser Etching with the Digitally Controlled Laser Handpiece-Xrunner?

OBJECTIVE: The aim of this study was to compare the shear bond strength (SBS), enamel surface characteristics, and the adhesive remnant index (ARI) scores of different etching methods. BACKGROUND DATA: Laser etching changes the physical characteristics of the enamel surface and these alterations hold promise for the conditioning of enamel for bonding procedures. A new Er:YAG laser handpiece is unique in its ability to digitally control size, shape, and depth of irradiated enamel area. MATERIALS AND METHODS: Ninety-eight premolar teeth were used in this study. Eighty of 98 teeth were divided into four experimental groups of 20 teeth each for SBS testing: (1) 37% phosphoric acid, (2) manual Er:YAG laser (120 mJ, 10 Hz, and 1.2 W), (3) manual Er,Cr:YSGG laser (45 mJ, 50 Hz, and 2.25 W), and (4) digitally controlled Er:YAG laser (Xrunner; 100 mJ, 10 Hz, 1 W). The SBS values and ARI scores were recorded. Eighteen teeth were used to evaluate the surface morphology with scanning electron microscopy and atomic force microscopy after etching and following debonding and restoration. RESULTS: Mean SBS value was 7.75 ± 2.5 MPa for Xrunner and 8.11 ± 3.5, 9.47 ± 3.3, and 7.11 ± 3.7 MPa for the acid, Er,Cr:YSGG, and Er:YAG groups, respectively (p = 0.148). However, the acid etching group demonstrated significantly higher ARI scores (p < 0.001). CONCLUSIONS: All etching methods caused enamel surface irregularities and were effectively restored to its original gloss. Laser etching was found to be an alternative to acid etching; however, the clinical success should be evaluated with further studies.

Comparación clínica de sistemas adhesivos con grabado selectivo en piezas primarias / A clinical comparison of bonding systems with selective etching in primary teeth

Objetivo: comparar el comportamiento clínico de restauraciones realizadas en piezas primarias con resinas compuestas utilizando un sistema adhesivo universal y un autoacondicionante de un solo frasco, ambos con grabado selectivo a esmalte. Métodos: Estudio experimental. Los datos obtenidos en 39 pacientes (5.47+1.67 años) con una o más piezas primarias vitales con lesiones amelodentinarias en 1 o 2 superficies restauradas con resinas compuestas utilizando Adper™ Easy One (AAG1 n= 66 restauraciones)fueron comparados con los obtenidos en 58 pacientes (5,76+ 1.58 años) utilizando Single Bond Universal 3M/ESPE (AAG2 n=81). En ambos grupos se realizó acondicionamiento del esmalte durante 30” con ácido fosfórico al 37 por ciento, previo a la aplicación de los sistemas adhesivos. Las 147 restauraciones fueron realizadas y evaluadas clínicamente por tres docentes calibrados (Kappa 0.96) en condiciones basales y en 2 controles posteriores (Ryge modificado). Se calcularon porcentajes y promedios de los porcentajes de fracasos de las restauraciones analizando los resultados a través del Test Normal para diferencia de medias. El proyecto fue aprobado por el Comité de Ética de la Facultad de Odontología de la Universidad de Buenos Aires (FOUBA) (120809-5). Resultados: El porcentaje medio de fracasos antes del primer control resultó 7.21 por ciento y 6.25 por ciento (p=0.85) y antes del segundo control 13.89 por ciento y 9.65 por ciento (p=0,50) en AAG1 yAAG2, respectivamente. Conclusión: El comportamiento clínico de las restauraciones realizadas con resinas compuestas utilizando un sistema adhesivo universal y un auto-acondicionante de un solo frasco, ambos con grabado selectivo a esmalte, reveló resultados similaresdurante el período bajo estudio.

Objective: to compare clinical performance of composite restorations placed in primary dentition using an universal adhesive and an onebottleself-etching system, both of them with selective enamel etching. Method: Experimental Design. Data obtained from 39 patients(5.47+1.67 years.) with one or more small and moderate carious lesions in vital deciduous teeth restored with resin composites usingAdper™ Easy One (AAG1 n= 66), were compared with the obtained in 58 patients (5,76+ 1.58 years) using Universal Single Bond3M/ESPE (AAG2 n=81). In both groups enamel was etched with phosphoric acid 37% during 30” prior to the application ofadhesive systems. Composite resin restorations (N=147) were placed and assessed by 3 calibrated operators (Kappa: 0.96) at baselineand after two appointments (Modified Ryge Criteria). Percentages and average of percentages of failures of restorations were calculated.Statistical analysis: Two sample normal test for the difference in means. Project approved by FOUBA Ethics Committee. (120809-5).Results: The average percentage of failures before the first control was 7.21 % and 6.25 % (p=0.85) and before the second control was13.89 % and 9.65% (p=0.50) in AAG1 and AAG2, respectively. Conclusions: In this work clinical performance of compositerestorations using two single components adhesive systems with previous enamel acid conditioning showed similar results during the periodunder study.

Influence of air abrasion and sonic technique on microtensile bond strength of one-step self-etch adhesive on human dentin.

The purpose of this in vitro study was to evaluate the microtensile bond strength of one-step self-etch adhesive to human dentin surface modified with air abrasion and sonic technique and to assess the morphological characteristics of the pretreated dentin surface. The occlusal enamel was removed to obtain a flat dentin surface for thirty-six human molar teeth. The teeth were randomly divided into three experimental groups (n = 12 per group), according to the pretreatment of the dentin: (1) control group, (2) air abrasion group, and (3) sonic preparation group. Microtensile bond strength test was performed on a universal testing machine. Two specimens from each experimental group were subjected to SEM examination. There was no statistically significant difference in bond strength between the three experimental groups (P > 0.05). Mean microtensile bond strength (MPa) values were 35.3 ± 12.8 for control group, 35.8 ± 13.5 for air abrasion group, and 37.7 ± 12.0 for sonic preparation group. The use of air abrasion and sonic preparation with one-step self-etch adhesive does not appear to enhance or impair microtensile bond strength in dentin.

Resin infiltration of fissure caries with various techniques of pretreatment in vitro.

The resin infiltration technique might be used for occlusal caries lesions in order to arrest their progression. This in vitro study evaluated the influence of various modifications of the infiltration technique on the penetration abilities of the infiltrant into occlusal lesions. Extracted human molars and premolars (n = 140) with non-cavitated white spot lesions were randomly allocated to 7 groups. As control, specimens were etched with 15% hydrochloric acid (HCl) gel for 120 s and resin infiltrated for 180 s (Icon; DMG). As modification HCl gel reduced in surface tension and viscosity with and without abrasives was applied using 3 different types of brushes either to oscillate or rub the HCl gel onto the enamel surface. The median maximum lesion depth was 1,232 µm (interquartile range 882-1,513). Compared with the control procedure [23% (16/50)] a higher percentage penetration was observed if the HCl gel was mixed with a small amount of abrasives were rubbed into the fissures using a modified brush with stiff bristles that were adjusted to the fissure relief for either 120 s [100% (64/100)] or 30 s [98% (61/100); p < 0.05; Mann-Whitney test]. All other experimental treatments resulted in penetration results in-between. It can be concluded that the use of an abrasive HCl gel in conjunction with a modified brush mostly enhances resin infiltration into fissure caries lesions.

Tensile bond strength of sealants following Er:YAG laser etching compared to acid etching in permanent teeth.

The aim of this in vitro study was to assess the effect of Er:YAG laser surface treatment on the tensile bond strength of a sealant in permanent teeth. A total of 30 sound third molars were selected and embedded in cold-cure acrylic resin. The enamel surfaces were flattened by a grinding. The teeth were randomly divided into three groups and pretreated as follows: (1) 37% phosphoric acid; (2) Er:YAG laser (1.5 ml/min water spray, 100 mJ energy output, 10 Hz frequency, focal distance 17 mm); (3) Er:YAG laser + 37% phosphoric acid. The treated surfaces were isolated by double adhesive Sellotape and after insertion of a split Teflon matrix at an isolated site, sealant was applied. The specimens were thermocycled and stored at 37°C in distilled water for 72 h, then subjected to a tensile bond strength test (50 kgf at 0.5 mm/min). The mean tensile bond strengths (± SD, in megapascals) were: 18.51 ± 5.68 in group 1, 8.06 ± 2.69 in group 2, and 17.33 ± 5.04 in group 3. Data were submitted to analysis of variance and the Tukey test. No significant difference were found between groups 1 (37% phosphoric acid) and group 3 (Er:YAG laser + 37% phosphoric acid) but treatment with the Er:YAG laser alone (group 2) resulted in significantly lower tensile bond strength than seen in the other groups. In this setting, the Er:YAG laser prepared the enamel surface for sealing but did not eliminate the need for acid etching before sealant application.

Effectiveness of an indirect bonding technique in reducing plaque accumulation around braces.

OBJECTIVE: To evaluate if the use of an indirect braces bonding protocol for localized enamel etching and adhesive application could help reduce plaque accumulation and demineralization around the brackets compared with a conventional direct-bonding technique. MATERIALS AND METHODS: Thirty patients were bonded with a split-mouth approach: two randomly selected opposite quadrants were used as the test sides and the other two as control sides. During the first 6 months, the plaque presence around the braces was recorded monthly according to a plaque accumulation index (PAI), as was the presence of demineralization. PAI values were measured at each of the four bracket sides for every bonded tooth. Analysis of variance was used to identify significant differences between different bracket margins and between test and control sides. RESULTS: Test and control sides differed significantly for PAI measurements from t(1) (1 month after bonding) to t(4) (4 months after bonding), with the highest value of significance (P < .001) at t(1) but with no significant differences from t(5) to t(7) (treatment end). Considering whole-mouth results, different bracket margin PAI scores did not differ significantly. PAI scores were higher at t(1) and progressively decreased during the treatment. At debonding, the onset of 21 new white spots was recorded overall for the control sides and eight new white spots for the test sides. CONCLUSION: Especially during the first 4 months after brackets placement, this indirect bonding protocol allowed for significant reduction in plaque accumulation around the braces and reduced onset of white spots during the orthodontic treatment.

Capacidad de penetración del adhesivo Adper-Silorano en dentina humana / Penetration capability of Adper-Silorane adhesive in human dentin

La reciente aparición de resinas compuestas en base a sistemas resinosos que se polimerizan por apertura de anillos (siloranos) que contraen menos del 1 por ciento y su sistema adhesivo compatible autoacondicionante (Adper-Silorano), vienieron a mejorar la integridad marginal de la restauración. Con la ayuda de la microscopía electrónica de barrido se comprobó al menos que este nuevo sistema penetra los tejidos dentarios y permite una estabilidad de la interfase de unión sin la formación de grietas. Serán necesarias investigaciones complementarias bajo fuerzas de tracción y microfiltración.(AU)

Capacidad de penetración del adhesivo Adper-Silorano en dentina humana / Penetration capability of Adper-Silorane adhesive in human dentin

La reciente aparición de resinas compuestas en base a sistemas resinosos que se polimerizan por apertura de anillos (siloranos) que contraen menos del 1 por ciento y su sistema adhesivo compatible autoacondicionante (Adper-Silorano), vienieron a mejorar la integridad marginal de la restauración. Con la ayuda de la microscopía electrónica de barrido se comprobó al menos que este nuevo sistema penetra los tejidos dentarios y permite una estabilidad de la interfase de unión sin la formación de grietas. Serán necesarias investigaciones complementarias bajo fuerzas de tracción y microfiltración.

Adhesión a dentina a través de distintos tratamientos del sustrato: estudio con confocal láser scanning microscope / Dentin adhesion by using different substrate treatments: a confocal laser scanning microscope study

El objetivo de este trabajo fue comprobar la adhesión a dentina y la adaptación a las paredes cavitarias de un agente adhesivo dentinario (AAD), con distintos tratamientos del sustrato, a través de hibridización por desmineralización con ácidos en alta concentración, hibridización reversa por desmineralización con ácidos en alta concentración e hipoclorito de sodio, reacción-integración con primers autoacondicionantes y oxidación-desproteinización con hipoclorito de sodio (AU)

Adhesión a dentina a través de distintos tratamientos del sustrato: estudio con confocal láser scanning microscope / Dentin adhesion by using different substrate treatments: a confocal laser scanning microscope study

El objetivo de este trabajo fue comprobar la adhesión a dentina y la adaptación a las paredes cavitarias de un agente adhesivo dentinario (AAD), con distintos tratamientos del sustrato, a través de hibridización por desmineralización con ácidos en alta concentración, hibridización reversa por desmineralización con ácidos en alta concentración e hipoclorito de sodio, reacción-integración con primers autoacondicionantes y oxidación-desproteinización con hipoclorito de sodio

Effect of acid etching time and technique on interfacial characteristics of the adhesive-dentin bond using differential staining.

Dentin bonding using the total-etch method has been claimed to be technique-sensitive. The aim of this study is to examine the effect of acid-etch variations on the dentin demineralization and interfacial structure of the adhesive-dentin bond using a differential staining technique. Single Bond adhesive with 35% phosphoric acid gel was used. The occlusal one-third of the crown was removed from 60 extracted, unerupted human third molars. Smear layers were created by abrading the dentin with 600 grit SiC under water for 30 s. The prepared teeth were randomly assigned to four groups according to etching time (Group 1, 10 s; Group 2, 15 s; Group 3, 30 s; Group 4, 60 s). In each group, the etching gel was: (i) applied and spread to the dentin surface and left to stand undisturbed; (ii) applied and gently agitated during etching; (iii) applied without using dispensing tips for the syringe and left for the same period as above. After rinsing, the etched dentin was then treated with the adhesive per manufacturers' instructions. 3-5 micro m thin sections of the adhesive/dentin (a/d) interface were cut with a microtome and stained with Goldner's trichrome. Stained, thin sections from each prepared tooth were imaged with light microscopy. The depth and extent of dentin demineralization, and the a/d interdiffusion zone were clearly visible by this differential staining microtechnique. The thickness of the interdiffusion zone increased as a function of etching time. However, the etchant gel application methods have a significant influence on dentin demineralization. Although agitating acid gel facilitates the penetration and etching into dentin, it should not be recommended, especially for longer etching time. These results indicated that the etching technique has a large effect on the profile of both dentin demineralization and interfacial structure.

Hydrolytic stability of methacrylamide in acidic aqueous solution.

In order to develop a more effective self-etching primer, with a longer lasting shelf life, we designed a self-etching primer comprised of methacrylamide, N-methacryloyl glycine, NMGly. In this study, the hydrolytic stability of the amide portion in the NMGly was examined. The difference in the hydrolytic stability between the methacrylamide and the methacrylate, 2-hydroxyethyl methacrylate, HEMA was then discussed. The addition of an acid to an aqueous solution allows for the hydrolysis of the ester portion in the methacrylate and for the production of methacrylic acid, MA and ethylene glycol, EG. From our study, the data clearly demonstrated that, if the storage duration of a commercially available self-etching primer is prolonged, then the functional methacrylates constituting the self-etching primer will be altered upon use. However, the hydrolytic stability of the amide portion in the methacrylamide, NMGly, designed as an acidic and/or hydrophilic monomer for the self-etching primer, was greater than the results achieved with the methacrylate, HEMA.

Accion de los "primers" autoacondicionantes sobre esmalte bovino sin cortar / The action of self-etching primers on untreated bovine enamel

El objetivo de este trabajo fue evaluar la acción de los primers autoacondicionantes sobre esmalte bovino sin cortar, mediante la observación de réplicas al MEB. Se evaluaron el Self-etching bond (Kuraray) y el Prompt-L pop (3M-Espe), y se compararon con el grupo de control con ácido fosfórico al 35 por ciento + single bond. Las réplicas mostraron que la acción del adhesivo autoacondicionante difiere de uno a otro y depende en gran medida de la composición del mismo. La presencia de esmalte aprismático dificulta la acción del adhesivo. El patrón más evidente se logró con el Prompt-L pop, el Self-etching bond produjo un patrón aceptable pero poco profundo y con precipitado de cristales embebidos en resina sobre la superficie. La utilización de grabado ácido previo a la colocación de los adhesivos autoacondicionantes en esmalte sin cortar favorece la obtención de un patrón de grabado más profundo. En conclusión, los primers autoacondicionantes no producen aún una efectiva penetración en esmalte aprismático (AU)

Accion de los "primers" autoacondicionantes sobre esmalte bovino sin cortar / The action of self-etching primers on untreated bovine enamel

El objetivo de este trabajo fue evaluar la acción de los primers autoacondicionantes sobre esmalte bovino sin cortar, mediante la observación de réplicas al MEB. Se evaluaron el Self-etching bond (Kuraray) y el Prompt-L pop (3M-Espe), y se compararon con el grupo de control con ácido fosfórico al 35 por ciento + single bond. Las réplicas mostraron que la acción del adhesivo autoacondicionante difiere de uno a otro y depende en gran medida de la composición del mismo. La presencia de esmalte aprismático dificulta la acción del adhesivo. El patrón más evidente se logró con el Prompt-L pop, el Self-etching bond produjo un patrón aceptable pero poco profundo y con precipitado de cristales embebidos en resina sobre la superficie. La utilización de grabado ácido previo a la colocación de los adhesivos autoacondicionantes en esmalte sin cortar favorece la obtención de un patrón de grabado más profundo. En conclusión, los primers autoacondicionantes no producen aún una efectiva penetración en esmalte aprismático

Development of self-etching primer comprised of methacrylamide, N-methacryloyl glycine.

In order to develop a more effective self-etching primer, it is helpful to understand how a functional monomer conditions the surface of the teeth.In this study, the reactivity by the carboxylic acid in the N-methacryloyl glycine (NMGly) on the calcium phosphate in hydroxyapatite or dentin was studied. The efficacy of the NMGly as a functional monomer for a self-etching primer was then examined. Applying NMGly to both the enamel and dentin resulted in an increase in the bond strength of resin, since the carboxylic acid in the NMGly decalcified the calcium phosphate in the hydroxyapatite and dentin. The bond strength to dentin achieved was higher than with the enamel. This difference was most likely due to different enamel and dentin adhesion mechanisms.

Adhesión de composites a esmalte y dentina con sistemas autoacondicionantes / Bonding of composites to enamel and dentin with self-conditioning systems

El objetivo de este trabajo fue evaluar la resistencia adhesiva de composites a tejidos dentarios, utilizando sistemas autocondicionantes. Se fijaron probetas de composite (Z-100, 3M) sobre superficies planas de esmalte y dentina con y sin acondicionamiento con ácido fosfórico (3M-gel) utilizando Promp L-Pop (ESPE) y Clearfil Liner Bond 2V (Kuraray) como adhesivos. LUego de 24 horas de almacenamiento en agua destilada a 37 grados C, se determinó la resistencia adhesiva bajo tensiones de corte. El análisis de varianza mostró el efecto significativo de los factores material empleado, tratamiento ácido y tejido considerado, así como varias de las interacciones entre ellos. Puede concluirse que si bien los sitemas autocondicionantes alcanzan valores aceptables en esmalte sin grabar, el empleo de ese acondicionamiento los incrementa significativamente. En dentina el efecto de este tratamiento fue significativo con el sistema Clearfil Liner Bond 2 V, mientras que no lo fue en el caso de Promp L-Pop. Sobre esta última superficie se obtuvieron valores inferiores a los logrados sobre esmalte (AU)