What is the correct angle of the blade face to the tooth for effective scaling or root planing?

For effective scaling or root planing, maintaining an angle of approximately 70° between the blade face and the tooth surface is optimal. This angle allows for efficient removal of calculus and plaque while minimizing trauma to the surrounding soft tissues.

At this angle, the cutting edge of the scaler or curette can effectively engage with deposits on the tooth surface, facilitating a smooth, thorough scaling action. This also helps in controlling the depth of penetration into the periodontal tissues, reducing the potential for discomfort and damage. An angle that is too steep or too shallow can compromise the effectiveness of the procedure, leading to inadequate cleaning or unnecessary injury to the root surfaces and adjacent gum tissue.

This understanding emphasizes the importance of technique in periodontal therapy—specifically, how instrument angulation can influence treatment outcomes in dental hygiene practices.