title: A comparative in vitro efficacy of conventional rotatory and chemomechanical caries removal: Influence on cariogenic flora, microhardness, and residual composition.
abstract: BACKGROUND
  Chemomechanical caries removal system is part of the minimal invasive dentistry; the aim of the study was to compare the amount of bacteria after caries removal with chemomechanical system and conventional rotatory instruments and to test the Vickers microhardness and micro-RAMAN analysis of residual dentin after excavation.
  
  
  METHODS
  Molars were induced for demineralization, confirmed with DIAGNOdent; Streptococcus mutans were inoculated into the cavities and filled. Caries removal was performed with rotatory instruments and chemomechanical system; surviving bacteria were cultured for 24 and 48 hours at 37°C. Vickers microhardness and micro-RAMAN analysis were tested after excavation. Data were analyzed with Wilcoxon, continuity correction, odds ratio, ANOVA post hoc Tukey test, and Spearman correlation.
  
  
  RESULTS
  Demineralization was significantly detectable at 240 hours of incubation; conventional rotatory instruments and chemomechanical caries removal were effective in 19.4%-22.6% and 25.8%-32.3%, respectively. Vickers microhardness of chemomechanical system was higher (P < 0.0001) than conventional rotatory instruments and comparable to healthy dentin. Micro-RAMAN analysis showed that healthy dentin is correlated to chemomechanical system (R (2) = 0.683, P < 0.00001) and drilling with burs (R (2) = 0.139, P < 0.00001).
  
  
  CONCLUSIONS
  The chemomechanical system is effective for caries elimination, comparable to conventional rotatory instruments; the remaining Vickers microhardness and composition surface tissue are similar to healthy dentin.
authors.affiliation: Dental and advanced Studies Research Center "Dr. Keisaburo Miyata", School of Dentistry State of Mexico, Mexico ; Deparment of Dental Materials, School of Dentistry, Autonomous University State of Mexico (UAEMex), State of Mexico, Mexico.
authors.forename: Rene
authors.initials: R
authors.lastname: Garcia-Contreras
authors.affiliation: Dental and advanced Studies Research Center "Dr. Keisaburo Miyata", School of Dentistry State of Mexico, Mexico ; Deparment of Orthodontics, School of Dentistry, Autonomous University State of Mexico (UAEMex), State of Mexico, Mexico.
authors.forename: Rogelio Jose
authors.initials: RJ
authors.lastname: Scougall-Vilchis
authors.affiliation: Dental and advanced Studies Research Center "Dr. Keisaburo Miyata", School of Dentistry State of Mexico, Mexico ; Deparment of Pediatric Dentistry, School of Dentistry, Autonomous University State of Mexico (UAEMex), State of Mexico, Mexico.
authors.forename: Rosalia
authors.initials: R
authors.lastname: Contreras-Bulnes
authors.affiliation: Department of Diagnostic and Therapeutic Science, Division of Pharmacology, Meikai University, Saitama, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakagami
authors.affiliation: Deparment of Nanomaterials, Center for Research in Sustainable Chemistry (CIQS), School of Chemistry, Autonomous University State of Mexico (UAEMex), State of Mexico, Mexico.
authors.forename: Raul Alberto
authors.initials: RA
authors.lastname: Morales-Luckie
authors.affiliation: Biomaterials Science, School of Dentistry, Meikai University, Saitama, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakajima
keywords: Cariogenic flora; RAMAN; Vickers microhardness; chemomechanical caries removal; conventional rotatory caries removal