Examinando por Materia "Microleakage"

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(Universidad Privada Norbert Wiener, 2012) Altamirano Canales, Dayvi Ramiro; Del Castillo Ayquipa, Armando
The objective of this research was to evaluate in vitro the degree of microleakage in the cementation of prefabricated fiberglass posts using two types of adhesive cementing agents (dual-cure resin cement and flowable resin). The sample consisted of 32 single-rooted teeth (lower premolars) recently extracted. All teeth underwent root canal treatments and were then randomly distributed into two groups: in 16 teeth, translucent fiberglass prefabricated posts were installed using dual-cure resin cement, and in the remaining 16 teeth, the same posts were cemented using flowable light-cured resin. The sample was coated with nail varnish on the entire length of the root and then immersed in 5% methylene blue for 7 days to allow passive filtration. The teeth were sectioned by wear to observe the microleakage of the dye, which was recorded through high-precision digital photographs. Microleakage was then measured using Adobe® Illustrator® CS5.5 with the “Transform” tool. The data were analyzed using the independent samples t-test, which showed a statistically significant difference between the study groups (p < 0.05). The study concluded that the degree of microleakage in the cementation of prefabricated fiberglass posts is lower with flowable resin compared to dual-cure resin cement.
Acceso abierto

(Universidad Privada Norbert Wiener, 2012) Gálvez Saldaña, Santos; Galvez Ramirez, Carlos Michell
The purpose of this study was to determine the degree of microleakage in composite resins in relation to the cavity preparation surface finish of class II cavities with a right-angle and bevel angle in dental pieces. The in vitro study was experimental, analytical, cross-sectional, prospective, and applicative in nature. Sample: 60 human teeth. Class II cavities were prepared in all, with 30 having a right-angle surface finish and 30 with a bevel-angle surface finish. All samples were filled with composite resin. They were hydrated in 0.9% sodium chloride for one week, and the apices were sealed with acrylic resin. A total of 250 thermocycling cycles at temperatures of 5°C and 55°C were performed. The samples were then immersed in 2% methylene blue for one week. Vertical, horizontal, and coronal cuts were made to evaluate all walls involved in this research, and then observed under an optical microscope at 10x magnification. As a result, in the vertical cut, the three respective degrees of microleakage showed average differences of 30%, 10%, and 20%. In the horizontal cut, the three degrees of microleakage showed average differences of 40%, 10%, and 40%. In the coronal cut, the four degrees of microleakage showed average differences of 20%, 57%, 27%, and 50%, all favoring the bevel-angle restorations. In conclusion, restorations with a bevel-angle cavity preparation surface finish exhibited less microleakage compared to restorations with a right-angle surface finish.
Acceso abierto
Comparison of the microfiltration degree in direct composite resin restorations using two Adper Single Bond 2 and Single Bond Universal adhesive systems
(Universidad Privada Norbert Wiener, 2019-06-19) Chipana Damian, Angel Abilio; Del Castillo Ayquipa, Armando
The purpose of this study was to determine the degree of microleakage in composite resins associated with the adhesives Adper Single Bond 2 and Single Bond Universal in a Class II Black cavity preparation. This in vitro study was quasi-experimental, prospective, and cross-sectional. Thirty upper premolars extracted for orthodontic reasons were collected, washed with 0.1% thymol solution for disinfection, and stored in physiological saline to prevent dehydration, following inclusion and exclusion criteria. The 30 samples were randomly divided into two groups: Group A (Adper Single Bond 2 adhesive system) and Group B (Single Bond Universal adhesive system with selective etching). The samples underwent Class II Black cavity preparations. They were subjected to 200 thermocycling cycles at temperatures of 5°C and 55°C, then immersed in 2% methylene blue solution for 24 hours. Microleakage identification was performed using photographs taken with a Canon T61 camera mounted on a tripod to ensure a consistent distance across all samples. Measurements were made in millimeters using Adobe Illustrator CS6 and converted to quantitative microleakage data through a simple three-rule calculation. Statistical analysis was conducted using the Student's t-test for independent samples. The results demonstrated that Adper Single Bond 2 exhibited greater microleakage, while Single Bond Universal showed a lower degree of microleakage. It was concluded that there are statistically and clinically significant differences between the two adhesive groups.