Hydrogen and carbamide peroxides used for in-office and at-home whitening treatments are potentially harmful to pulp causing various alterations. Also characteristic and quite frequent is the presence of dental sensitivity. The aim of this paper is to review the appearance of post-whitening tooth hypersensitivity in clinical cases treated with different techniques. A study of patients (N = 56) with 5 different dental whitening techniques was managed: in-office light activated, with 35% hydrogen peroxide (N1 = 10); in-office chemical activated, also with 35% hydrogen peroxide (N2 = 10); in-office with custom-formed trays using 35% carbamide peroxide (N3 = 10); at-home with custom-formed trays (N4 = 16, 8 with 10% carbamide peroxide and 8 with 3.5% hydrogen peroxide); and at-home with a 6% carbamide peroxide varnish (N5 = 10). For the set of cases, sensitivity was 55% and varied between slight and intense. All whitening procedures can cause hypersensitivity, although it does not always occur. When present (31-55% of all the patients treated), hypersensitivity is not usually very intense and affects only a few teeth in each patient. Greater sensitivity was observed with in-office chemical activated (70%) and light-activated (100%) whitening techniques. So, after dental whitening treatment, dental hypersensitivity is to be expected, independently of technique and product used, in at least one out of two patients.