RESUMO Objetivo: Analisar e comparar as tensões de Von Mises e a distribuição das tensões principais no osso palatino ao redor de implantes palatinos em Ortodontia Lingual (OL) para sistemas de implantes palatinos unitários ou duplos com comprimentos variados do braço de alavanca. Métodos: Foram delineados dois grupos para o presente estudo: Grupo 1 - com sistema de implante palatino unitário e Grupo 2 - com sistema de implantes palatinos duplos. Em seguida, os grupos foram divididos em dois subgrupos, com base no comprimento do braço de alavanca, para analisar as tensões no osso palatino ao redor do implante. Para cada sistema, foram construídos dois modelos 3D de elementos finitos (MEF) de casos com extração bilateral de primeiros pré-molares superiores. Braquetes linguais (slot 0,018”) foram posicionados no centro das coroas clínicas. Nos dois sistemas, foram aplicados 150g de força de retração nos dentes anteriores, e o software ANSYS v. 12.1 foi usado para analisar e comparar as tensões no osso palatino ao redor dos implantes. Resultados: Foram observados maiores níveis de tensões na parte interna rosqueada no osso cortical. A magnitude das tensões de Von Mises foi maior no Grupo 2 (0,63MPa e 0,65MPa) em comparação ao Grupo 1 (0,29MPa e 0,29MPa). De forma semelhante, foi observada maior magnitude das tensões principais no Grupo 2 do que no Grupo 1. Maiores tensões foram observadas na região apical da interface osso/implante no tecido ósseo esponjoso. Conclusão: A tensões de Von Mises e as tensões principais no osso palatino ficaram dentro do limite ideal em ambos os grupos. Ambos os sistemas de implantes palatinos (unitário e duplo) foram seguros para o uso clínico em pacientes com força de retração de 150g.

ABSTRACT Objective: To analyze and compare the Von Mises stress and principal stress distribution in palatal bone around the palatal implant in lingual orthodontics (LiO) for single and double palatal implant systems with varying lengths of lever arm. Methods: Two groups were assessed: single (Group 1) and double (Group 2) palatal implant systems, which were further divided into two subgroups, based on lever arm length, for analyzing stress in the palatal bone around the implant. Hence, two 3D finite element models of bilateral maxillary first premolar extraction cases were constructed in each system. Lingual brackets (0.018-in slot) were positioned at the center of the clinical crown. In both systems, 150g of retraction force was applied, and ANSYS v. 12.1 software was used to analyze and compare stress in the palatal bone around the palatal implant. Results: In this study, higher stress was observed at the inner threaded interface of cortical bone. Magnitude of Von Mises stress was higher in Group 2 (0.63 MPa and 0.65 MPa) in comparison to Group 1 (0.29 MPa and 0.29 MPa). Similarly, magnitude of principal stress was higher in Group 2, in comparison to Group 1. Higher stress was observed in the apical region of the implant-bone interface of cancellous bone. Conclusion: This study concluded that the Von Misses stress as well as principal stress in the palatal bone were within the optimal limit in both groups. Finally, it can be concluded that both systems (single and double palatal implant) were safe for the patients in clinical use of 150g of retraction force.

Combined effect of polycarboxylate type superplasticizer and sodium sulphate on the hydration of fly ash blended Portland® cement has been studied by using different techniques. Water consistency, setting times, non-evaporable water contents, water percolation, air contents, compressive strengths and expansion in corrosive atmosphere were determined. Hydration products were examined with the help of DTA and X-ray diffraction techniques. It is found that the superplasticizer reduces the pore size and its adsorption on cement surfaces is decreased in the presence of sodium sulphate. Mechanism of hydration is discussed.

Protease inhibitors in legumes are one of the most promising weapons that confer resistance against insects by inhibiting proteases present in the gut of insect larvae. In the present study, trypsin inhibitor activity was detected in the seed flour extracts of 10 selected varieties of chickpea. The presence of inhibitor was confirmed by dot blot analysis. All the varieties showed inhibitory activity in vitro against the gut protease of Helicoverpa armigera (HGP). Trypsin inhibitor has been purified to near homogeneity to 60.46 fold and 29.20% recovery from chickpea seeds using heat denaturation, ammonium sulphate fractionation, DEAE-Sephadex A-25 and Sephadex G-75. The purified inhibitor showed a single band on SDS-PAGE corresponding to molecular mass of 30,000 Da. The purified inhibitor was active over a wide pH range although it retained maximum activity between pH 6 and 10. The inhibitor protein was stable up to 80°C but retained only 40% of activity when heated at 100°C for 20 min. The inhibitor lost its activity completely at 121°C. The chickpea trypsin inhibitor exhibited inhibitory activity against Helicoverpa armigera both in vitro and in vivo. In insect bioassay, a progressive decline in larval weight, growth and survival as well as temporal extension of larval growth was observed after feeding H. armigera larvae on diet supplemented with increasing concentrations of chickpea trypsin inhibitor. The adult emergence was also adversely affected by the inhibitor. It may be concluded that chickpea trypsin inhibitor has insecticidal potential against H. armigera.