Effects of Cathepsin K Inhibitors on Dentin Erosion: An in vitro Study.

Cathepsin K (catK) modulates the degradation of dentin collagen. This study aimed to evaluate the effects of catK inhibitors on dentin erosion. Dentin beams were eroded (4 times/d for 5 days) and immersed in deionized water (negative control), 0.1 <sc>M</sc> NaCl, 0.3 <sc>M</sc> NaCl, 0.5 <sc>M</sc> NaCl, or 1 μ<sc>m</sc> odanacatib (each n = 16) for 30 min after each erosive challenge. Erosive dentin loss (EDL) and demineralized organic matrix (DOM) thickness were evaluated profilometrically. Additionally, dentin beams were demineralized, immersed in the respective solutions for 30 min each (n = 5), and then incubated in artificial saliva for 5 days. Dentin collage degradation was evaluated by quantifying the levels of the C-terminal peptide of type I collagen (CTX), C-terminal cross-linked telopeptide of type I collagen (ICTP), and hydroxyproline (HYP) in the incubation media. Significantly lower EDL and dentin collagen degradation (CTX, ICTP, and HYP) and thicker DOM layers were observed in the samples treated with 0.3 <sc>m</sc> NaCl and 1 μ<sc>m</sc> odanacatib than in those treated with deionized water (all p &lt; 0.05). The samples treated with 1 μ<sc>m</sc> odanacatib showed significantly lower levels of CTX and HYP than those treated with 0.3 <sc>M</sc> NaCl (all p &lt; 0.05). The present findings support the potential use of catK inhibitors in controlling dentin erosion.