The light at the other end of the tunnel: heeding two decades of regeneration research to reclaim natural tooth preservation.

Despite advancements in biomimetic and regenerative dentistry, contemporary prosthetic restorations, though clinically successful, remain fundamentally imperfect replications of the natural tooth's inherent biological perfection. Crucially, while these advancements remain vital, the dental discipline has increasingly shifted from preventive focus to a reparative focus. Given that dental decay-the primary concern in a dental practice-is a highly predictable and preventable condition and that tooth loss is a largely avoidable outcome, we propose that the future of the discipline lies in transitioning focus from substitution of lost or damaged tooth parts to the preservation of what is hitherto biologically irreplaceable. Reviewing current dental practice and research, this perspective article challenges the dental community to maximize tooth longevity by acknowledging that in dentistry-more than any other medical discipline-prevention remains the cure. Our challenge invokes the 'paradox of knowledge'-where expanded understanding unveils deeper unknown-to bring to the fore that the more we uncover the intricacies of the dental bioarchitecture, the clearer it becomes that preservation of the invaluable and irreproducible natural tooth structure, rather than its repair, is the achievable path forward. This realization warrants a paradigm "U-turn" towards the light at the starting end of the reparative tunnel. We contend that a successful shift from tooth replacement or regeneration to tooth preservation is twofold: it requires a mindful appraisal of contemporary scientific knowledge concerning the tooth mechano-biology as an unparalleled organ in the body, as well as a fundamental reexamination of the values of a profession existing to alleviate people's suffering.