Histologische Untersuchungen über mögliche Hitzeschäden an Knochen und Knorpel beim Bohren und Schleifen

Summary

In skull bone and septum cartilage holes were bored with rose trepans and diamond cutters of various sizes (2–20) and at different revolutions (5,000–42,000 rev/min) with and without the use of cooling fluid. The specimens were examined histologically. Borings with rose trepans without cooling fluid cause sometimes considerable heat lesions up to a depth of 30 μ. Bone shows the more severe lesions. The use of cooling fluid reduces the damage quite considerably (burns zone up to a maximum depth of 12 μ). In the normal range of up to 10,000 rev/min practically no heat lesions occur. In the high range above 20,000 rev/min the lesions are often only plaque-shaped. Water jet or spray cooling is superior to droplet cooling. Diamond cutters cause more severe lesions. Boring and grinding in the highest range (up to 300,000 rev/min) without cooling fluid cause very deep burns (up to 56 μ).