In vitro Study of the Role of Human Neutrophil Enzymes on Root Caries Progression

Zamperini C. A., Aydin B., Sroussi H. Y., Bedran-Russo A. K.

CARIES RESEARCH, vol.55, no.2, pp.99-107, 2021 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 55 Issue: 2
  • Publication Date: 2021
  • Doi Number: 10.1159/000512482
  • Journal Name: CARIES RESEARCH
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, BIOSIS, Biotechnology Research Abstracts, CAB Abstracts, CINAHL, EMBASE, Food Science & Technology Abstracts, MEDLINE, Veterinary Science Database
  • Page Numbers: pp.99-107
  • Keywords: Root caries, Biofilm, Neutrophils, Enzymes, Collagen
  • Dokuz Eylül University Affiliated: No


The role of the host immune system in caries progression is mainly speculative, and it is believed that it entails the enzymatic degradation of the dentin organic matrix. The aim of this study was to evaluate the proteolytic effect of human neutrophil enzymes on root caries progression. For this, specimens of bovine root dentin were divided into 4 groups (n = 30): caries (C), caries + neutrophils (C + N), no caries (Control), and no caries + neutrophils (Control + N). Streptococcus mutans biofilm (10(5) CFU/mL) was grown on the root surface to artificially induce root carious lesions (C and C + N groups). Specimens were then exposed to neutrophils (5 x 10(6) cells/mL) for 48 h (C + N and Control + N groups). Caries development and neutrophil exposures were repeated a 2nd and 3rd time. Caries depth (CD) and dentin demineralization (DD) were assessed by infiltration of rhodamine B using fluorescence microscopy. Collagen fibril ultrastructure was characterized under a polarized microscope with Picrosirius red staining. There were no significant differences (p > 0.05) in CD and DD between the C and C + N groups for 1, 2, and 3 caries-neutrophil exposures. Immature collagen was significantly less present in the carious groups (C, p = 0.003; C + N, p = 0.01) than in the noncarious groups in the most superficial 200 mu m. We thus concluded that human neutrophil enzymes did not influence short-term root caries progression, and immature collagen fibrils were more susceptible to degradation during S. mutans-induced root caries progression.