ABSTRACT
PURPOSE: This study aimed to evaluate the effect of bonding protocols and the type of orthodontic resin on the adhesion of microorganisms, degree of conversion (DC), and shear bond strength (SBS) of metallic brackets to enamel. METHODS: A total of 60 bovine incisors were prepared and randomly divided into 6 groups (nâ¯= 10): "bonding protocol" (A: phosphoric acid; AXT: A+Transbond™ XT primer adhesive [all Transbond™ products from 3M Unitek, Monrovia, CA, USA]; and SE: Transbond™ Plus Self Etching Primer) and "orthodontic resin" (XT: Transbond™ XT adhesive paste and CC: Transbond™ Plus Color Change). After bonding, the samples were subjected to thermocycling (5000 cycles) and to the SBS test. Bond failures were classified according to the adhesive remnant index (ARI). Next, 60 enamel blocks were sterilized in ethylene oxide in order to perform the CFU (Streptococcus mutans) assay in vitro to analyze the colony forming units (CFU/mL). Then, 60 discs of each orthodontic resin were made to measure the DC. The SBS (MPa), CFU/mL, and DC (%) data were statistically analyzed by two-way analysis of variance and Tukey's test (5%) was performed for the DC. RESULTS: CFU and SBS revealed no significance for all factors (Pâ¯> 0.05). Tukey's test showed that A_XT (acid+Transbond™ XT adhesive paste) presented the highest DC (70.38%⯱ 10.5), while AXT_XT (acid+Transbond™ XT primer adhesive+Transbond™ XT adhesive paste) showed the lowest (23.47%⯱ 10.4). An ARI score of 2 was more frequent for the CC resin and an ARI score of 4 for the XT resin. CONCLUSION: The CC resin does not reduce adhesion of S. mutans around orthodontic brackets and the bonding protocol did not influence the SBS, although the SE and A_XT groups contributed to a better DC.
ABSTRACT
El objetivo de este estudio fue determinar la prevalencia de accidentes ocupacionales en estudiantes de Odontología de la Universidad Federal de Rio Grande del Norte (UFRN), Brasil y el nivel de conocimiento de estos sobre exposición ocupacional, medidas preventivas y manejo post exposición. Los datos fueron recogidos a través de un cuestionario, con información referente a edad, género y período cursado, además de la ocurrencia de accidentes ocupacionales, medidas pre y post exposición de 150 estudiantes. Los datos fueron registrados en un banco de datos del Statistical Package for the Social Science (SPSS) 17.0 y sometidos a análisis descriptivo. De los 150 estudiantes evaluados, 45.3% eran hombres y 54.7% mujeres. La prevalencia de accidentes fue de 45.3%, ocasionados por perforación durante el lavado y condicionamiento del instrumental (30.9%) o en procedimientos clínicos (21.8%), por salpicaduras en el ojo (11.8%), contacto directo con sangre (10.9%) y por otras causas (24.6%). De los 68 accidentados, solo 14.7% se realizó exámenes para detectar infección por HBV y/o VIH después del accidente, 86.8% de los estudiantes no recibió ningún tratamiento. De la muestra, 88.7% estaban vacunados contra la hepatitis B y de estos, 48.7% completaron el esquema de vacunación. A pesar de que los estudiantes de Odontología presentaron un adecuado conocimiento sobre medidas preventivas y manejo post exposición, hubo una considerable prevalencia de accidentes ocupacionales e inadecuadas conductas post exposición, reflejando la necesidad de la adopción y/o intensificación de programas preventivos, garantizado el egreso de profesionales con alto nivel de preparación en materia de riesgo laboral.
The aim of this study was to determine the prevalence of accidents in dental students at the Federal University of Rio Grande do Norte (UFRN), Brazil, and the knowledge level about their occupational exposure, preventive measures and post-exposure management. Were collected through a questionnaire, data on age, sex and academic semester, as well as the occurrence of accidents, pre and post-exposure. Were recorded in the database of the Statistical Package for the Social Sciences (SPSS) 17.0 and submitted to a descriptive analysis. Of the 150 students evaluated, 45.3% were men and 54.7% women. The prevalence of accidents was 45.3%, caused by drilling in the wash of instrumental (30.9%) or dental procedures (21.8%), due to splash in the eye secretion (11.8%), direct contact with blood (10.9%) and other causes (24.6%). Of the 68 victims, only 14.7% were tested for HBV infection and / or HIV and after the accident, 86.8% of students did not undergo any treatment. Of the sample, 88.7% were vaccinated against hepatitis B and of these 48.7% completed the vaccination schedule. Despite the dental students have an adequate knowledge of preventive measures and post-exposure management, there was a considerable prevalence of occupational accidents and inappropriate behavior after exposure, reflecting the need for adoption or intensification of preventive programs, ensuring the egress of professionals with a high level of preparedness in biohazard.
