Salt and pepper effect in IOPA is seen in:
Intraoral radiographs in some cases reveal a peculiar trabecular pattern of the maxilla and mandible, characterized by an apparent coarsening of some trabeculae and the blurring and disappearance of others, resulting in a salt and pepper effect. In general, thinning of the lamina dura and circular radiolucencies in the alveolar bone are also found.
Shafer's Oral pathology, 7th ed, pg 768
Sjogren syndrome
Thalassemia
Sickle cell anemia
Condensing osteitis