1 Dental implants can also promote dental health. 2  When a tooth is missing, the jaw bone is not stimulated, which can cause the bone to deteriorate. 3  An implant stimulates the bone as a natural tooth would, helping to prevent bone loss.
Longitudinal waves, also known as l-waves, are waves in which the displacement of the medium is in the same direction as, or the opposite direction to, the direction of travel of the wave.
Sound waves are known as longitudinal because the medium in which they travel â air, water or whatever else â vibrates in the same direction as the wave itself. Loudspeakers, for example, move air molecules back and forth in the same direction as the vibration of the speaker cone. In both cases, the water or air molecules remain, largely, in the same place as they started, as the wave travels through the material. They are not shifted, en masse, in the direction of the wave.