Stage theories of health behavior change assume that individuals pass through qualitatively different stages on their way to the adoption of health behaviors. Three common stages (preintention, intention and action) can be defined by stage transitions included in current stage theories and supported by evidence. The present study examines whether transitions between these stages can be predicted by social cognition variables derived from prevailing health behavior theories. At two points in time, the motivation for interdental hygiene behaviors and oral self-care was assessed in 288 participants recruited in dental practices. Stage progression and regression over time were analyzed using discriminant function analysis. Progression from preintention to intention was predicted by action planning, whereas coping planning and self-efficacy predicted transitions from intention. Regression from action was predicted by self-efficacy. Results support the distinction of three common stages. Findings are discussed in terms of their contribution to health behavior theory.