Teeth whitening is the most conservative way to have whiter teeth compared to veneers and crowns. There are 2 types of teeth whitening system: at-home and in-office. We normally recommend at-home bleaching because it has more stable result, less complications and cost much less in long term.
The older the teeth are, the harder to be whitened. The picture showed a good teeth whitening result for a 50+ years old patient.