title: Capacity of a hydroxyapatite-lysozyme combination against Streptococcus mutans for the treatment of dentinal caries.
abstract: BACKGROUND
  One current strategy for the treatment of carious lesions is the use of biomaterials with antimicrobial activity.
  
  
  OBJECTIVE
  The aim of this study was to evaluate a combination of hydroxyapatite and lysozyme for the treatment of dentinal caries by measuring Streptococcus mutans counts before carious tissue sealing, and 24 h, 1 month, and 6 months after treatment.
  
  
  METHODS
  Forty permanent third molars were selected, and flat dentin surfaces were prepared. The teeth were exposed to a cariogenic challenge with S. mutans. After challenge, the dentinal caries were collected from five specimens. The remaining specimens were treated with a mixture of hydroxyapatite and lysozyme in sodium laureth sulfate and sealed with composite resin. S. mutans counts were obtained 24 h, 1 month, and 6 months after sealing.
  
  
  METHODS
  The results were evaluated by descriptive statistics and Wilcoxon signed-rank test.
  
  
  RESULTS
  a significant reduction in S. mutans (CFU/mL) was observed in dentinal lesions 1 month after treatment with hydroxyapatite/lysozyme in sodium laureth sulfate (P = 0.0254). Comparison of S. mutans counts obtained 24 h, 1 month, and 6 months after treatment revealed reductions only at the 1-month time point (P = 0.0318).
  
  
  CONCLUSIONS
  the combination of hydroxyapatite and lysozyme may be an alternative for reducing the S. mutans burden in dentinal caries.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Pontifícia Universidade Católica de Campinas, Campinas, São Paulo, Brazil.
authors.forename: Sérgio Luiz
authors.initials: SL
authors.lastname: Pinheiro
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Pontifícia Universidade Católica de Campinas, Campinas, São Paulo, Brazil.
authors.forename: Nathany Nunes
authors.initials: NN
authors.lastname: da Rocha
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Pontifícia Universidade Católica de Campinas, Campinas, São Paulo, Brazil.
authors.forename: Mariane de Lourdes Hernandes Martins
authors.initials: Mde L
authors.lastname: Peres
keywords: Dental caries; Streptococcus mutans; enzyme