A meshwork has a layer forming a mesh, the mesh layer being disposed between parallel tension ribbons which are opposite one another in pairs. The tension ribbons have a thermoplastic bonding layer on the side facing the mesh layer and are connected to one another and to the mesh layer via the bonding layer. The mesh layer takes the form of a plastic net having meshwork webs which are connected to one another in a materially bonded manner and which are stretched and form diamond-shaped meshes, the longitudinal diagonals of which extend transversely to the tension ribbons.

The purpose of the present invention is to provide a lightweight composite material structure while suppressing a drop in strength. In a composite material structure, which is configured as a fiber-reinforced plastic composite material extending in one direction and having a plurality of holes (5) formed at intervals in a row in the one direction and which is subjected to a tensile load and/or a compressive load in the one direction, a peripheral region (3a) around the holes (5) comprises a first area (10) obtained by bending composite material, which is reinforced using continuous fibers that have been made even in the longitudinal direction, so that the center line of the width (W) of the composite material weaves between adjacent holes (5) and zigzags in the one direction. The tensile rigidity and/or compressive rigidity in the one direction of the peripheral region (3a) around the holes (5) is lower than the tensile rigidity and/or the compressive rigidity in the one direction of the other regions (3b) that surround the peripheral regions (3a).

A dental preform comprises a central portion formed by a plurality of first wire-like elements extending mostly in a first direction, and a first resin. An annular peripheral portion passes round the central portion perpendicularly to the first direction. The peripheral portion comprises second wire-like elements and a second resin. The peripheral portion comprises a plurality of layers arranged on one another perpendicularly to the first direction. Each layer has at least one turn formed by at least one of the second wire-like elements, the at least one second wire-like element presenting a longitudinal direction that is offset with respect to the first direction by an angle comprised between 10 and 80 or between 100 and 170. The second wire-like elements of two consecutive layers present opposite orientations.