Introduction This paper seeks to answer two straightforward questions: (1) What is quality of life? And (2) How does quality of life relate to dental implant treatment? Unfortunately, neither question will be answered here, nor, probably, anywhere else. The reason is, in the first case, that there is little unanimity concerning the meaning of the concept of quality of life (QoL), and there may be even less agreement when specifying it to comprise oral health-related quality of life (OHRQoL). As for the second question, the inability to answer is caused by the scarcity of research in the field, which is understandable, considering the vagueness of the QoL concept. One reason for this deplorable situation is that when invoking the concept of QoL, one also invokes behavioral and social sciences, which are inherently different from the natural sciences in their fundamental disagreement about simple concepts, even more so An concerning complex phenomena such as QoL. Research about oral implants has been dominated by natural science—not without disagreements, to be sure—but still the research is rather unanimous about basic concepts such as tooth or mouth; social/behavioral science has not reached agreement about the meaning of society, state, personality, or similar basic concepts, not to mention the content of QoL. Still, implant researchers should be more aware than other natural scientists of the problems in new paradigms in science and in new ways of thinking, since one may well place Per Ingvar Brånemark among those pioneers opening up new ways of thought. The situation in social sciences is, however, that several paradigms may flourish simultaneously for a long time, while the change between paradigms is faster—and also cumulative—in natural séance. This has not always been the case— consider, for example, the transition between a geocentric and a heliocentric world view in astronomy, which took hundreds of years—but with the mature and well-established present-day natural sciences, new breakthroughs may take only a decade or so, eg, the discovery of DNA or, for that matter, osseointegration. However, orientation in the jungles of social concepts still requires sharp tools and great patience among those wanting precision. An overview of paradigms in social and behavioral science is outside of the scope of this aper.1 It will be enough just to sketch some of the ideas in the health research domain. Health and its counterpart, disease, are prime examples of the conceptual confusions that occur in social and behavioral science. A basic realization is, in my opinion, that neither health nor disease nor QoL are some kind of essences to be found and researched out in the world.2 be They are social concepts and are established in a very specific human relationship: the clinical encounter.