Which type of periodontal instrument is characterized by a triangular cross-section and tapers to a sharp point?

The correct choice is hand scaler, which is distinguished by its triangular cross-section and sharp point. Hand scalers are specifically designed for removing supragingival calculus and plaque from the tooth surfaces, particularly in areas that may be difficult to access with other instruments. The triangular shape of the blade allows for effective adaptation to the tooth’s contours, making it easier to reach into interproximal spaces and along the edges of the gumline. The sharp point of the scaler provides an advantage in accessing tight areas and breaking up deposits on the enamel surface.

Gracey curettes, while important periodontal instruments, have a curved and rounded design that is not triangular. They are meant primarily for subgingival scaling and root planing in specific areas of the dentition due to their unique angle and blade design, which is tailored for specific teeth.

Universal curettes have a rounded design that allows for adaptation to various tooth surfaces, but they do not have the tapered, sharp point characteristic of hand scalers. They are less pointed and more versatile across different surfaces than the specifically designed hand scaler.

Periodontal probes are diagnostic instruments used to measure pocket depth and are not designed for scaling or calculus removal. They typically have a rounded tip and are calibrated with markings to assess periodontal status