Dental, medical, and veterinary apparatus and supplies used in dental radiography, namely, bite blocks for holding and positioning image capturing devices, patient comfort cushions used on image capturing devices, infection control barriers used on image capturing devices, x-ray beam limiting and position indicating devices, alignment systems comprised of bite blocks for holding and positioning image capturing devices, indicator arms for aligning bite blocks to aiming rings, and aiming rings for aligning x-ray beam limiting and position indicating devices to position the x-ray source, teeth, and image capturing devices relative to each other, and protective covers especially designed for digital sensor cables that are used with dental apparatuses