Final answer:
The correct answer is Posterior teeth with deep pits and fissures. Pit & fissure sealants are applied to molars and premolars to prevent dental caries by sealing off grooves that can harbour plaque and bacteria.
Step-by-step explanation:
The most common indication for placing pit & fissure sealants would be Posterior teeth with deep pits and fissures. This preventative measure is typically used on the molars and premolars in the back of the mouth, which are prone to accumulating food particles and bacteria due to their intricate grooves and indentations. Sealants are applied to the enamel of these teeth to help prevent dental caries (cavities), which can occur when plaque and bacteria build up in these hard-to-clean areas and produce acids that erode the tooth enamel.
Dental caries can progress through the enamel and cause more severe damage to the underlying dentin or even reach the tooth's inner pulp. Using sealants on teeth with deep pits and fissures can significantly reduce the incidence of cavities, the need for fillings or tooth extractions, and overall dental suffering.