INTRODUCTION: Removable partial dentures (RPDs) are fabricated to replace the lost teeth of a partially edentulous individual. The serviceability of an RPD is dependent on the bond strength at the resin-framework interface. The esthetically unacceptable display of metal clasps, the increased weight of the prosthesis, the potential for metallic taste, and allergic reactions to metals led to the introduction of a number of thermoplastic materials in clinical practice such as nylon and acetal resins. An alternative restoration material (poly-ether-etherketone [PEEK]) has been successfully used over the last years. OBJECTIVES: to evaluate the shear bond strength and the effect of aging on bond strength of two different resin based materials to polyether-ether-ketone [PEEK]. MATERIALS AND METHODS: Fifty two PEEK cylinders was prepared. Specimens was randomly assigned into two parallel groups, 26 specimens each according to the resin materials used. The bond strength and aging of resin material to poly-ether-ether-ketone [PEEK] was evaluated. RESULTS: the initial shear bond strength of PMMA to PEEK was significantly higher than that of composite resin to PEEK. However, after aging process the shear bond strength of PMMA to PEEK decreased while that of composite resin to PEEK remained unchanged. There was no significant difference between the shear bond strength of both PMMA and composite resin to PEEK after aging. CONCLUSIONS: PMMA can be used as a veneering material with PEEK with comparable results to traditionally used composite resin. Moreover, owing to the adequate bond strength between PEEK and PMMA, PEEK frameworks could be relined in the traditional method similar to metal frameworks

Purpose To compare the effect of different designs of guiding sleeves on heat generation during implant surgery while using different cooling fluid temperatures. Material and Methods Temperature measurements were performed during guided implant site preparation in bovine rib samples using two K‐ type thermocouples at 2 mm and 8 mm depths. Three groups were tested according to guiding sleeve design: conventional cylindrical sleeve, open C‐shaped sleeve, and modified cylindrical sleeve. Each group was irrigated with three fluid temperatures: 10°C, 15°C, and 20°C. The groups were compared using Kruskal Wallis test followed by post hoc comparisons with Bonferroni correction. The level of statistical significance was set at p = 0.05. Results Surgical guides with conventional cylindrical sleeve design showed significantly higher heat generation during implant site preparation than guides with both the open C‐shaped and the modified cylindrical sleeve designs at both 2mm and 8mm depths. The difference between C‐shaped and modified cylindrical sleeves was not significant in any group. Using pre‐cooled irrigation fluids (10°C and 15°C) reduced the generated heat; however, the differences within the same group were not statistically significant. Conclusions The use of a surgical guide with the conventional cylindrical sleeves led to higher heat generation than other sleeve designs, which might reach or near the critical threshold of bone thermal necrosis. Using surgical guides with open sleeves or modified cylindrical sleeves could be helpful in irrigation fluid delivery and decreasing the generated heat.

The aim of this research is to study the factors affecting a mechanical coating of fennel seeds. These factors are coating speed, temperature and time, and seed batch. The main results in this study were: The maximum fennel-seed germinations of 55.9, 61.2 and 42.9 % were obtained by using coating-unit speed of 28 rpm, coating time of 15 minute, coating temperature of 30 C o and coating with "Fe + Zn", "Fe + Zn + Cersan" and clay respectively. Meanwhile, the minimum fennel-seed germinations of 3.5, 4.5 and 1.5 % were obtained by using coating-unit speed of 36 rpm, coating time of 65 minute, coating temperature of 70 C o and coating with the same constitutions respectively. The maximum machine capacity of coated fennel-seeds of 4.8 kg/h was obtained using seeds-batch mass of 2.5 kg and coating-unit speed of 36 rpm. Meanwhile, the minimum machine capacity of coated fennel-seeds of 0.65 kg/h was obtained using seeds-batch mass of 0.5 kg and coating-unit speed of 20 rpm. The operation and production costs at optimum parameters (batch mass of 2.5 kg, coating-unit speed of 28 rpm, coating temperature of 30 0 C, coating time of 15 minutes and coating with "Fe + Zn + Cersan") were 10.63 L. E./h and 3037 L.E./ton respectively.

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