Effect of different decontamination agents on the bond strength of CAD/CAM blocks and repair composite materials / Efecto de diferentes agentes descontaminantes sobre la resistencia de unión de bloques CAD/CAM y resinas compuestas

Abstract The purpose of this study was to examine the effect of different decontamination agents on the bond strength of saliva-contaminated CAD/CAM blocks and repair composite materials. Two hunderd eighty 3-mm-thick specimens were prepared from four different CAD/CAM materials: Katana Zirconia UTML disc, IPS e.max CAD block, Shofu block, and Vita Enamic block. Each material was divided into seven different subgroups (N=70). Group 1 had a clean surface. The other groups were comprised of the samples, which were contaminated with human saliva: group 2: negative control (non-cleaned); group 3: cleaned with water spray; group 4: cleaned with 70% ethanol; group 5: cleaned with Ivoclean; group 6: cleaned with Katana Cleaner; and group 7: cleaned with phosphoric acid. After the decontamination protocols, the resin composite cylinders were bonded to the CAD/CAM surfaces with a thin layer of dual-cured resin cement. The samples were stored for 24 hours at 37°C in distilled water. Then, they were subjected to a shear bond strength test (SBS). The values were recorded, and fracture types were evaluated using a microscope. Data were analyzed using two-way ANOVA and Tukey's post-hoc test. Generally, all decontaminating agents improved the SBS of composites to Katana Zirconia UTML, IPS e.max, and Vita Enamic materials (p<0.05). However, for Shofu materials, group 6 samples exhibited significantly higher bond strength values as compared with group 2 samples (p=0.026). The highest SBS values were seen in the phosphoric acid-treated group in Katana zirconia materials (26.45 ± 9.38 MPa), whereas the lowest values were seen in group 2 samples in Shofu materials (13.17±3.40 MPa). Each decontaminant agent improved the bond strength of composites to the contaminated CAD/CAM materials. If saliva is not cleaned before adhesive procedure, SBS values may decrease. All decontamination agents can be used safely on zirconia, lithium-disilicate glass-ceramic, hybrid ceramic, and polymer-infiltrated ceramic surfaces.

Resumen El propósito de este estudio fue examinar el efecto de diferentes agentes descontaminantes sobre la fuerza de unión de bloques CAD/CAM contaminados con saliva y materiales compuestos de reparación. Se prepararon doscientas ochenta muestras de 3 mm de espesor a partir de cuatro materiales CAD/CAM diferentes: disco Katana Zirconia UTML, bloque IPS e.max CAD, bloque Shofu y bloque Vita Enamic. Cada material se dividió en siete subgrupos diferentes (N=70). El grupo 1 tenía una superficie limpia. Los otros grupos estaban compuestos por muestras que estaban contaminadas con saliva humana: grupo 2: control negativo (no limpio); grupo 3: limpiado con agua pulverizada; grupo 4: limpiado con etanol al 70%; grupo 5: limpiado con Ivoclean; grupo 6: limpiado con Katana Cleaner; y grupo 7: limpiado con ácido fosfórico. Después de los protocolos de descontaminación, los cilindros de composite de resina se adhirieron a las superficies CAD/CAM con una fina capa de cemento de resina de curado dual. Las muestras se almacenaron durante 24 horas a 37°C en agua destilada. Luego, fueron sometidos a una prueba de resistencia al corte (SBS). Se registraron los valores y se evaluaron los tipos de fracturas utilizando un microscopio. Los datos se analizaron mediante ANOVA de dos factores y la prueba post-hoc de Tukey. En general, todos los agentes descontaminantes mejoraron el SBS de los composites con los materiales Katana Zirconia UTML, IPS e.max y Vita Enamic (p<0,05). Sin embargo, para los materiales Shofu, las muestras del grupo 6 exhibieron valores de fuerza de unión significativamente más altos en comparación con las muestras del grupo 2 (p=0,026). Los valores más altos de SBS se observaron en el grupo tratado con ácido fosfórico en materiales de circonio Katana (26,45 ± 9,38 MPa), mientras que los valores más bajos se observaron en las muestras del grupo 2 en materiales Shofu (13,17 ± 3,40 MPa). Cada agente descontaminante mejoró la fuerza de unión de los composites a los materiales CAD/CAM contaminados. Si no se limpia la saliva antes del procedimiento adhesivo, los valores de SBS pueden disminuir. Todos los agentes descontaminantes se pueden utilizar de forma segura en superficies de circonio, cerámica de vidrio de disilicato de litio, cerámica híbrida y cerámica con infiltraciones de polímeros.

In vitro research of oral microscope-assisted implant surface decontamination / 华西口腔医学杂志

OBJECTIVES@#To investigate the effect of oral microscope-assisted surface decontamination on implants in vitro.@*METHODS@#Twelve implants that fell off because of severe peri-implantitis were collected, and decontamination was carried out on the surfaces of implants through curetting, ultrasound, titanium brushing, and sandblasting at 1×, 8×, or 12.8× magnifications. The number and sizes of residues on the implants' surfaces after decontamination were determined, and the decontamination effect was analyzed according to the thread spacing in the different parts of the thread.@*RESULTS@#1) The 8× and 12.8× groups scored lower for implant surface residues than the 1× group (P<0.000 1), and the 12.8× group scored lower than the 8× group (P<0.001); 2) no difference in residue score was found between the wide and narrow thread pitch (P>0.05), and the 8× and 12.8× groups had lower scores than the 1× group (P<0.001); 3) the lowest number of contaminants was observed at the tip of the thread, whereas the highest was observed below the thread, and the difference was significant (P<0.001). However, the thread pitch had no effect on the number of contaminants in different areas (P>0.05); 4) the residue scores of the 8× and 12.8× groups were lower than those of the 1× group at the thread tip and above, sag, and below the thread of the implants (P<0.05).@*CONCLUSIONS@#Residues on the surfaces of contaminated implants can be effectively removed by using an oral microscope. After decontamination, the residues of pollutants were mainly concentrated below the thread of the implants, and the thread pitch of the implants had no significant effect on the residues.

Persistent Bactericidal Action by a Silver Disinfectant on Surfaces of Hospital Furniture.

Aims: In hospitals, surfaces are often colonized by potentially pathogenic micro organisms which can remain alive for long periods of time, thus playing a major role in hospitalacquired infections. One way to overcome this drawback could be to use disinfectants with long-term action. Recent studies have shown that not only do disinfectants containing silver present an immediate effect, reducing the surface bacterial load, but that this action also appears persistent in time. This work assesses the bactericidal activity of a long-lasting disinfectant complex composed of silicon oxide, silver ions and a cationic surfactant (BACTERCLINE ENERGY BLAST) applied on the surfaces of two surgery ward rooms and left in place for different amounts of time (15 min and 72 hours). Study Design: An experimental study. Place and Duration of Study: The investigation was carried out in two rooms of a surgical ward at the Villa Erbosa health care facility in Bologna (Italy) over a period of seven weeks. Methodology: The samples were taken using contact plates (diameter: 24 cm2) containing an adequate agar culture medium (Tryptic Soy Agar). After incubation at the temperature of 36±1ºC for 24 and 48h, the number of colonies was counted and the statistical analysis of results was performed. Results: The product was able to achieve a high degree of decontamination (around 90%) immediately after application and that, after 72 hours, decontamination remained at about 55%. The results are statistically significant. Conclusion: It may be concluded that the tested product could be profitably used to decontaminate surfaces in hospital wards.

Use of a Steam Generator for Disinfection of Hospital Ward Room Surfaces.

Objectives: The present work examines the ability of a method — based on saturated overheated dry steam — to decontaminate surfaces in patient rooms in a surgery ward. Study Design: An experimental study. Place and Duration of Study: The investigation was carried out in two rooms of a surgical ward at the Villa Erbosa health care facility in Bologna (Italy) over a period of three weeks. Methodology: Samples, using 24 cm diameter contact plates containing an agar-base medium, were taken before and after steam decontamination obtained using a professional steam generator. Results: After steam treatment, the number of CFU (colony forming unit) present on the surfaces analyzed was reduced by 88.41%. Conclusion: These results are significant and indicate that the use of steam provides good results in terms of decontamination of the surfaces in ward rooms. Furthermore steam not leaves residues that could be the source of subsequent chemical contamination of the surfaces.