Stress Analysis Of Different Configurations Of 3 Implants To Support A Fixed Prosthesis In An Edentulous Jaw

This study's aims was to evaluate the stress distribution in a mandibular implant-supported prosthesis and peri-implant bone considering implant quantity, diameter and position using linear 3-D finite element analysis. Models of an anterior jaw comprised 4 groups according to implant quantity, diameter, and position: control group C, 5 regular implants; R, 3 regular implants; W, 3 wide implants; and DTR, 3 regular implants with the distal ones tilted 30° distally. The cantilever was loaded with an axial load of 50 N. Data was evaluated using von Mises stress on implants and maximum principal stress and microstrain on the bone. The W group showed the lowest value of maximum principal stress in peri-implant bone of the loaded side (4.64 MPa) when compared to C (5.27 MPa), DTR (5.94 MPa), and R (11.12 MPa). Lower stress values in the loaded implants were observed in the experimental groups when compared to the C group. However, the unloaded implants presented opposite results. All the screws of the W group presented lower stress values when compared to the C group. However, the R and DTR groups presented an increase in stress values with the exception of the loaded screw. A reduction in the number of implants associated with wider implants reduced the stress in the bone and prosthetic components.2816773Branemark, P.I., Svensson, B., van Steenberghe, D., Ten-year survival rates of fixed prostheses on four or six implants ad modum Branemark in full edentulism (1995) Clin Oral Implants Res., 6 (4), pp. 227-231. , DecMendonca, D.B., Prado, M.M., Mendes, F.A., Borges, T.F., Mendonca, G., Prado, C.J., Comparison of masticatory function between subjects with three types of dentition (2009) Int J Prosthodont., 22 (4), pp. 399-404. , Jul-AugBranemark, P.I., Engstrand, P., Ohrnell, L.O., Grondahl, K., Nilsson, P., Hagberg, K., Branemark Novum: a new treatment concept for rehabilitation of the edentulous mandible. 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Biological aspects of the immature stages of Ceraeochrysa everes (Banks) (Neuroptera: Chrysopidae) Aspectos biológicos dos estágios imaturos de Ceraeochrysa everes (Banks) (Neuroptera: Chrysopidae)

A knowledge of the behavior and biological aspects of natural enemies is extremely important for the establishment of biological control programs. Biological aspects of the larvae, pre-pupae and pupae of the predator Ceraeochrysa everes (Banks) were studied. Larvae of the adult F1 generation were reared in the laboratory (25 ± 2°C, 65 ± 10 % RH and 14h photophase) on eggs of the Angoumois grain moth Sitotroga cerealella (Olivier). The duration and viability of the embryonic period, development of the immature stages and egg-adult period were evaluated. The mean embryonic period was 5.0 days, while the mean durations of the first, second and third instars were: 5.1 ± 0.03; 4.3 ± 0.05 and 4.5 ± 0.05 days, respectively, with viability exceeding 90%. Duration of the larval, pre-pupal and pupal stages averaged 13.9 ± 0.07; 5.7 ± 0.07 and 9.6 ± 0.12 days, respectively. Duration of the biological cycle was 34 ± 0.11 days on average. S. cerealella eggs were not suitable for rearing C. everes under laboratory conditions because they affected predator development.<br>Para o estabelecimento de um programa de controle biológico, o conhecimento de alguns aspectos biológicos e de comportamento dos inimigos naturais é de extrema importância. Os aspectos biológicos do desenvolvimento larval e pupal do predador Ceraeochrysa everes (Banks) foram estudados. Larvas oriundas de adultos da geração F1 foram mantidas em laboratório a 25 ± 21°C, 70 ± 10 % UR e fotofase 14 horas, sendo alimentadas com ovos de Sitotroga cerealella (Olivier). A duração e viabilidade do período embrionário, estágios imaturos de desenvolvimento e o período de ovo a adulto foram avaliados. O período embrionário foi em média de 5,0 dias, enquanto que as durações médias para o primeiro, segundo e terceiro instares foram de 5,1 ± 0,03; 4,3 ± 0,05 e 4,5 ± 0,05 dias, respectivamente, com viabilidade superior a 90 %. Os estágios larval, pré-pupal e pupal apresentaram duração média de 13,9 ± 0,07; 5,7 ± 0,07 e 9,6 ± 0,12 dias, respectivamente. A duração do ciclo biológico foi de 34 ± 0,11 dias em média. Ovos de S. cerelella não foram adequados para a manutenção de C. everes em laboratório, por interferir no desenvolvimento do predador