The following intraoral functions may be performed in the practice of dental hygiene: Preliminary dental examination; Dental prophylaxis, which includes: Scaling and root planing; or Polishing a tooth or a restoration; Placing and removing perio dressings, including an initial dressing; Placing sealants; Taking impressions for study models, custom fluoride trays, or athletic mouth guards; Exposing a dental x-ray; Performing a brush biopsy; Placing subgingival medicaments; Cementing temporary crowns or restorations; and Performing any duty that a dental assistant, or a dental assistant who is listed on the roster of dental assistants recognized as qualified in orthodontics or general duties, may perform. A dental hygienist may administer local anesthesia by infiltration and local anesthesia by inferior alveolar nerve block only after Board recognition as provided in this chapter. A dental hygienist may perform manual curettage in conjunction with scaling and root planning only after meeting the requirements of Regulation .12 of this chapter. A dental hygienist may administer nitrous oxide only after Board recognition as provided in this chapter.