Algarni, Amnah A.Ungar, Peter S.Lippert, FrankMartinez-Mier, E. AngelesEckert, George J.González-Cabezas, CarlosHara, Anderson T.2018-06-152018-06-152018-07Algarni, A. A., Ungar, P. S., Lippert, F., Martínez-Mier, E. A., Eckert, G. J., González-Cabezas, C., & Hara, A. T. (2018). Trend-analysis of dental hard-tissue conditions as function of tooth age. Journal of Dentistry, 74, 107-112. https://doi.org/10.1016/j.jdent.2018.05.011https://hdl.handle.net/1805/16524Objective This retrospective in-vitro study investigated tooth age effect on dental hard-tissue conditions. Methods Unidentified extracted premolars (n = 1500) were collected and their individual age was estimated (10–100 (±10) years old (yo)) using established dental forensic methods Dental caries, fluorosis and tooth wear (TW) were assessed using the International Caries Detection and Assessment System (ICDAS; 0–5 for crown and 0–2 for root), Thylstrup-Fejerskov (TFI; 0–9) and Basic Erosive Wear Examination (BEWE; 0–3) indices, respectively. Staining and color were assessed using the modified-Lobene (MLI) (0–3) and VITA shade (B1-C4) indices, respectively. Relationships between indices and age were tested using regression models. Results Starting at age ∼10yo, presence of caries increased from 35% to 90% at ∼50yo (coronal), and from 0% to 35% at ∼80yo (root). Caries severity increased from ICDAS 0.5 to 2 at ∼40yo and from ICDAS 0 to 0.5 at ∼60yo for coronal and root caries, respectively. Presence of TW increased from 25% (occlusal) and 15% (smooth-surfaces) to 100% at ∼80yo. TW severity increased from BEWE 0.5 to 2 at ∼50yo (occlusal) and ∼0.3 to 1.5 at ∼50yo (smooth-surfaces). Percentage and severity of fluorosis decreased from 70% to 10% at ∼80yo, and from TFI 1 to 0 at ∼90yo, respectively. Percentage of extrinsic staining increased from 0% to 85% at ∼80yo and its severity increased from MLI 0 to 2 at ∼70yo. Color changed from A3 to B3 at ∼50yo (crown), and from C2 to A4 at ∼85yo (root). Conclusions Aging is proportionally related to the severity of caries, TW, staining, and inversely to dental fluorosis. Teeth become darker with ageenPublisher PolicyagingenameldentinArticle