Which handpiece is typically straight and used to access cavities?

• A. Air turbine handpiece
• B. Slow straight hand piece
• C. Rubber dam punch
• D. Slow contra-angle handpiece

Answer: (B)

Access to the pulp chamber is best achieved with a straight-line approach. A straight handpiece allows the bur to advance along the long axis of the tooth, giving direct visibility and precise control during the initial entry into the tooth structure. Using it at a slow speed enhances tactile feedback and minimizes heat buildup and wobble, which helps in carefully removing dentin and shaping the cavity without deflecting the bur off the walls. That combination—straight alignment plus controlled, slower rotation—makes the slow straight handpiece the most suitable choice for creating an access cavity.

The rubber dam punch isn’t a handpiece at all, so it doesn’t fit the function here. A slow contra-angle handpiece has an angled head, which is useful when working around restricted spaces, but its angle makes maintaining a straight-line access more difficult. The air turbine handpiece (high-speed) is great for rapid cutting, but its high speed and typical design don’t favor the steady, straight approach needed for starting an access cavity.