title: Different bacterial models for in vitro induction of non-cavitated enamel caries-like lesions: Microhardness and polarized light miscroscopy analyses.
abstract: The aim of this study was to compare different bacterial models for in vitro induction of non-cavitated enamel caries-like lesions by microhardness and polarized light microscopy analyses. One hundred blocks of bovine enamel were randomly divided into four groups (n = 25) according to the bacterial model for caries induction: (A) Streptococcus mutans, (B) S. mutans and Lactobacillus acidophilus, (C) S. mutans and L. casei, and (D) S. mutans, L. acidophilus, and L. casei. Within each group, the blocks were randomly divided into five subgroups according to the duration of the period of caries induction (4-20 days). The enamel blocks were immersed in cariogenic solution containing the microorganisms, which was changed every 48 h. Groups C and D presented lower surface hardness values (SMH) and higher area of hardness loss (ΔS) after the cariogenic challenge than groups A and B (P < 0.05). As regards lesion depth, under polarized light microscopy, group A presented significantly lower values, and groups C and D the highest values. Group B showed a higher value than group A (P < 0.05). Groups A and B exhibited subsurface caries lesions after all treatment durations, while groups C and D presented erosion-type lesions with surface softening. The model using S. mutans, whether or not it was associated with L. acidophilus, was less aggressive and may be used for the induction of non-cavitated enamel caries-like lesions. The optimal period for inducing caries-like lesions was 8 days.
authors.affiliation: Department of Pediatric Dentistry, Cruzeiro Do Sul University-UNICSUL, São Paulo-SP, 01506-000, Brazil.
authors.forename: Priscila Hernández
authors.initials: PH
authors.lastname: De Campos
authors.affiliation: Department of Pediatric Dentistry, Camilo Castelo Branco University-UNICATELO, São Paulo-SP, 04204-002, Brazil.
authors.forename: Mariane Emi
authors.initials: ME
authors.lastname: Sanabe
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry, Rio Grande Do Sul Federal University-UFRGS, Porto Alegre, RS, 90035-003, Brazil.
authors.forename: Jonas Almeida
authors.initials: JA
authors.lastname: Rodrigues
authors.affiliation: Department of Pediatric Dentistry, Cruzeiro Do Sul University-UNICSUL, São Paulo-SP, 01506-000, Brazil.
authors.forename: Danilo Antonio
authors.initials: DA
authors.lastname: Duarte
authors.affiliation: Patients with Special Needs, Cruzeiro Do Sul University-UNICSUL, São Paulo-SP, 01506-000, Brazil.
authors.forename: Maria Teresa Botti Rodrigues
authors.initials: MT
authors.lastname: Santos
authors.affiliation: Department of Pediatric Dentistry, Cruzeiro Do Sul University-UNICSUL, São Paulo-SP, 01506-000, Brazil.
authors.forename: Renata Oliveira
authors.initials: RO
authors.lastname: Guaré
authors.affiliation: Department of Pediatric Dentistry, Araçatuba School of Dentistry, São Paulo State University - UNESP, Araçatuba, SP, 16015-050, Brazil.
authors.forename: Cristiane
authors.initials: C
authors.lastname: Duque
authors.affiliation: Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of Bern-UNIBE, Bern, CH, 3010, Switzerland.
authors.forename: Adrian
authors.initials: A
authors.lastname: Lussi
authors.affiliation: Department of Pediatric Dentistry, Cruzeiro Do Sul University-UNICSUL, São Paulo-SP, 01506-000, Brazil.
authors.forename: Michele Baffi
authors.initials: MB
authors.lastname: Diniz
mesh_terms: D000818:Animals; D018441:Biofilms; D002417:Cattle; D003731:Dental Caries / Q000382:microbiology* / Q000473:pathology; D003743:Dental Enamel / Q000382:microbiology* / Q000473:pathology; D006245:Hardness Tests; D007779:Lactobacillus acidophilus / Q000254:growth & development / Q000502:physiology; D007780:Lacticaseibacillus casei / Q000254:growth & development / Q000502:physiology; D008954:Models, Biological; D013295:Streptococcus mutans / Q000254:growth & development / Q000502:physiology; D017001:Tooth Demineralization / Q000382:microbiology
keywords: bacteria; hardness tests; microscopy; tooth demineralization; tooth enamel