Final answer:
The question pertains to the annual percentage of adults who have their teeth cleaned by a dentist, and the best-educated guess based on related information about dental hygiene and fluoride in water is 72%, although specific survey results are not provided.
Step-by-step explanation:
The question asks about the nationwide percentage of adults who have their teeth cleaned by a dentist yearly. To find the answer, we can refer to the text that mentions a goal for 80% of Americans to have access to water with sufficient fluoride to prevent tooth decay by 2020. We can make a reasonable assumption that this goal is closely related to general dental hygiene practices, which would include regular teeth cleaning by a dentist. Although no explicit statistic is provided for annual teeth cleanings, we can infer that if 80% is a goal for fluoridated water coverage, a similar or slightly lower figure might apply for regular teeth cleanings, as not everyone with access to fluoridated water may visit the dentist regularly. Thus, the best answer from the provided options would be 72%, option 2, although this is an educated guess rather than a fact provided by the materials.
From a health perspective, maintaining clean teeth is vital to preventing dental diseases such as gum disease. The Table 1.38 Flossing Frequency for Adults with Gum Disease and the information regarding deciduous and permanent teeth development stages emphasize the importance of regular dental care, including teeth cleaning. The mention of fluoride's role in preventing tooth decay further underscores the need for proper dental hygiene. However, to precisely answer the question at hand, one would need specific survey results or studies that directly report the percentage of adults receiving annual dental cleanings.