Final answer:
The human-needs theory is what assists dental hygienists in understanding the link between human-need fulfillment and behavior, particularly through the work of Abraham Maslow and his hierarchy of needs.
Step-by-step explanation:
The theory that helps dental hygienists understand the relationship between human-need fulfillment and human behavior is the human-needs theory. This perspective, which is rooted in humanism, suggests that individuals are motivated by a hierarchy of needs that must be met in order for them to achieve their fullest potential. The concept of human-needs relates closely to the work of Abraham Maslow and his well-known hierarchy of needs. According to Maslow, humans have certain needs in common which need to be fulfilled in a specific order, culminating in self-actualization. These needs range from basic physiological needs to safety, love and belonging, esteem, and finally, self-actualization.