This study assessed the impact on happiness and quality of life of the cosmetic treatment of frontal teeth. This was compared with the impact of a restorative, not primarily cosmetic, treatment in the (pre)molar region on happiness and quality of life. The hypothesis that a cosmetic dental treatment makes a person happier or improves the quality of one’s life was not supported by the results of the present study. In fact, oral health-related quality of life appeared to decline after the dental cosmetic treatment. Further research is needed to assess whether the results of the present study can be replicated in a larger sample and how the findings can be explained.