Numerous investigators have reported patients' postcementation sensitivity with glass-ionomer luting agents. This information has been predominantly anecdotal and unsupported by data. This paper reports on the actual perceptions of patients who had restorations cemented with both glass-ionomer and zinc phosphate luting agents. Forty-five patients were randomly selected and received two cast restorations, one cemented with glass-ionomer cement and the other with zinc phosphate cement, also by random assignment. After 1 week, patients returned to complete a self-administered evaluation of perceived sensitivity. Neither luting agent resulted in greater sensitivity when used according to its manufacturer's instructions.