Final answer:
Orthophosphoric acid, known as phosphoric acid, is used in dentistry as an enamel etchant at a concentration of around 37% to roughen the enamel surface, enhancing adhesion for various dental procedures.
Step-by-step explanation:
Orthophosphoric acid, also known as phosphoric acid, is commonly used in dentistry as an enamel etchant. The concentration typically used for this purpose is around 37%, which is effective for etching tooth enamel before the application of sealants, bonding agents, or orthodontic brackets. Orthophosphoric acid works by roughening the enamel surface to enhance adhesion properties.
Pure orthophosphoric acid forms colorless crystals that melt at 42 °C and is commercially available as a thick 82% solution often referred to as syrupy phosphoric acid. However, the 37% concentration is preferred in dental applications for its effectiveness and relative safety compared to higher concentrations. Controls are necessary when using higher concentrations of orthophosphoric acid to balance the benefits and risks, similar to how fluoride concentrations are managed in toothpaste.