ABSTRACT
OBJECTIVE: To assess the antibacterial effect of red laser using different photosensitizers such as methylene blue and malachite green on monoradicular premolars contaminated with E. faecalis ATCC 29212. METHODS: This was an in vitro experimental study. Monoradicular premolars (44, 45, 34, and 35) were used, which were treated with ProTaper Next. After instrument change, irrigation, disinfection, and aspiration were performed with 2 ml of 4% NaOCl with a NaviTip 30°G needle (Ultradent, South Jordan, UT, USA). Group 1: RL + MB (red laser associated with methylene blue photosensitizer), group 2: RL + MG (red laser associated with malachite green photosensitizer), and group 3: control (no treatment). The E. faecalis strain was cultured on trypticase soy agar (TSB) (Difco, Detroit, MI, USA) and incubated at 37°C for 24 h. After the incubation period, colony-forming units (CFU/ml) of each group were counted using the plate count method. The ANOVA test was used with a significance level of p < 0.05. RESULTS: Group 1 had the lowest antibacterial contamination as it averaged only 530 ± 581.3 CFU/ml, while group 2 had the highest contamination with an average of 1990 ± 542.5 CFU/ml. Comparison revealed that there were statistically significant differences between the RL + MB and RL + MG groups (p < 0.001). CONCLUSIONS: Group 1 had the best antimicrobial potential because it presented the lowest contamination in CFU/ml of E. faecalis compared to group 2 and group 3.
ABSTRACT
OBJECTIVE: To evaluate the effects of polymerization conducted by using LED lamps of different wavelengths (polywave and monowave) on the compressive strengths of nanohybrid composite resins Filtek™ Bulk Fill - 3M and 3M™ Filtek™ Z350 XT. MATERIALS AND METHODS: The study was prospective, experimental in vitro, and comparative. The sample consisted of nanohybrid composite resins. The sample size (n) was 100 specimens, divided into 10 groups. CRIS (Checklist for Reporting In-vitro Studies) Guidelines were used for writing this article. RESULTS: There were statistically significant differences between all groups with P < 0.001. Group 2 (nanohybrid composite resin blocks 3M™ Filtek™ Z350 XT with Monowave LED lamps) showed the highest compressive strength of 238.36±34.69N; CI (213.55-263.18) N. This was followed by Group 4 (nanohybrid composite resin blocks 3M™ Filtek™ Z350 XT with Poliwave LED lamps, High Power) and Group 6 (nanohybrid composite resin blocks 3M™ Filtek™ Z350 XT with Poliwave LED lamps, Soft Star), with compressive strengths of 222.33 ± 53.09N, and 209.21 ± 22.52N, respectively. CONCLUSIONS: Significant differences were found between the compressive strengths of 3M™ Filtek™ Z350 XT and Filtek™ Bulk Fill - 3M resins, and that of resins photopolymerized with monowave and polywave LED lamps and halogen light. Thus, the types of light and lamp directly influence the compressive strengths of the composite resins.
ABSTRACT
El objetivo del estudio fue evaluar la efectividad de los sellantes de fosas y fisuras empleando diferentes métodos para limpiar y preparar dichas estructuras, para ello se seleccionó 15 pacientes que presentaban sus cuatro primeros molares permanentes, los cuales se prepararon con agentes de limpieza como: piedra pómez con agua, pasta profiláctica fluorada, pasta profiláctica no fluorada y agua sola, a los 6 meses de aplicados los sellantes, tiempo en el que estuvieron sometidos bajo las mismas condiciones clínicas, se realizó un examen clínico para evaluar la presencia de los sellantes; donde se encontró que las molares tratadas con piedra pómez tuvieron menor efectividad, mientras en las que se aplicaron sólo agua tuvieron un mayor número de sellantes presentes en boca. Por ello, la limpieza de molares con fuertes lavados de agua tienen un promedio de retención similar o mejor que las pastas profilácticas y piedra pómez.
Subject(s)
Humans , Dental Caries/prevention & control , Oral Hygiene , Pit and Fissure SealantsABSTRACT
El presente estudio fue transversal y descriptivo, sobre una muestra de 50 pacientes que acuden de manera rutinaria sin signos ni síntomas a nivel de los senos maxilares a la Clínica Integral del Adulto de la Facultad de Odontología de la Universidad Nacional Federico Villarreal. Los resultados mostraron la importancia que tiene la radiografía panorámica como protocolo para iniciar cualquier tratamiento odontológico, se demostró que hay un porcentaje importante de patologías diversas de senos maxilares que pueden ser pre-diagnosticadas a la intervención del Médico Otorrino, contribuyendo de manera importante a la prevención de la presentación de los signos y síntomas de dichas patoogías en los senos maxilares.
Subject(s)
Humans , Dental Clinics , Radiography, Panoramic , Maxillary Sinus/diagnostic imaging , Epidemiology, Descriptive , Cross-Sectional StudiesABSTRACT
This paper considers the design of a software sensor (or soft-sensor) for the on-line estimation of the biological activities of a colony of aerobic micro-organisms acting on activated sludge processes, where the carbonaceous waste degradation and nitrification processes are taken into account. These bioactivities are intimately related to the dissolved oxygen concentration. Two factors that affect the dynamics of the dissolved oxygen are the respiration rate or the oxygen uptake rate (OUR) and the oxygen transfer function (K(l)a). These items are challenging topics for the application of recursive identification due the nonlinear characteristic of the oxygen transfer function, and to the time-varying feature of the respiration rate. In this work, OUR and the oxygen transfer function are estimated through a software sensor, which is based on a modified version of the discrete extended Kalman filter. Numerical simulations are carried out in a predenitrifying activated sludge process benchmark and the obtained results demonstrate the applicability and efficiency of the proposed methodology, which should provide a valuable tool to supervise and control activated sludge processes.
