Velsko IM, Fellows-Yates JA, Aron F, Hagen RW, Frantz LAF, Loe L, Rodriguez Martinez JB, Chaves E, Gosden C, Larson G, Warinner C*. Microbial differences between dental plaque and historic dental calculus are related to oral biofilm maturation stage. Microbiome 7:102. DOI: 10.1186/s40168-019-0717-3