What likely caused a dark film with strange-looking teeth during radiograph mounting?

A dark film with strange-looking teeth in radiographic images is indicative of overexposure and improper packet placement. Overexposure occurs when the film is exposed to an excessive amount of radiation, leading to excessive darkening of the image. This can cause the detail in the image to become obscured, resulting in the strange appearance of the teeth.

Proper packet placement is also crucial for obtaining a clear image. If the radiographic film is not positioned correctly in relation to the teeth, it may result in distorted or unclear images. This distortion, combined with overexposure, can create a film that is not only darker than normal but also presents an anomalous representation of dental anatomy.

Other factors, such as incorrect processing temperatures and the use of expired films, can certainly affect the quality of a radiograph. However, they would more likely lead to fogging or other less distinct changes, rather than the pronounced darkening and shapeless appearance characteristic of overexposure. Therefore, in this context, overexposure and improper packet placement accurately explain the issues observed in the radiograph.