title: Are bovine teeth a suitable substitute for human teeth in in vitro studies to assess endotoxin load in root canals?
abstract: The present study aimed to determine the feasibility of using bovine teeth as a suitable alternative for human teeth, in experiments involving in vitro endotoxin contamination. Twenty bovine central incisors and 20 human single-root premolars had their dental crowns removed and root lengths set at 16 mm. Root canals were prepared up to #60 K-file size and sterilized with cobalt-60 gamma irradiation (20 kGy, 6 h). The teeth were randomly divided into four groups: G1-bovine teeth (bovine negative control, n = 10), G2-human teeth (human negative control, n = 10), G3-bovine teeth, inoculated with Escherichia coli (055:B55) LPS, and G4-human teeth inoculated with E. coli LPS. The G1 and G2 groups were exposed to apyrogenic water. After the teeth had been incubated at 37 °C and atmospheric humidity for 24 h, the samples of solutions in the main canals were collected with apyrogenic absorbent paper tips. LPS levels were quantified using Limulus Amebocyte Lysate assay. The data obtained were statistically analyzed using one-way ANOVA, with a significance level of 5%. A high amount of endotoxin was detected in the inoculated human teeth (G4) when compared to the sterilized teeth (G2), as well as in the inoculated bovine teeth (G3) when compared to the inoculated human teeth (G4). However, there was no statistical difference between bovine teeth before and after the E. coli endotoxin inoculation. Therefore, under the mentioned experimental conditions, the use of bovine teeth should not be a choice for laboratory research on endotoxin contamination.
authors.affiliation: Clinical Department, Dental School, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Tiago André Fontoura de
authors.initials: TA
authors.lastname: Melo
authors.affiliation: Clinical Department, Dental School, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Grasiela Sabrina Longhi
authors.initials: GS
authors.lastname: Gründling
authors.affiliation: Endodontics Division, Dental School, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Francisco
authors.initials: F
authors.lastname: Montagner
authors.affiliation: Clinical Department, Dental School, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Roberta Kochenborger
authors.initials: RK
authors.lastname: Scarparo
authors.affiliation: Clinical Department, Dental School, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: José Antônio Poli de
authors.initials: JA
authors.lastname: Figueiredo
authors.affiliation: Clinical Department, Dental School, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Fabiana Vieira
authors.initials: FV
authors.lastname: Vier-Pelisser
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002417:Cattle; D003035:Cobalt / Q000737:chemistry; D003786:Dental Pulp Cavity / Q000382:microbiology*; D004926:Escherichia coli; D005240:Feasibility Studies; D006801:Humans; D066298:In Vitro Techniques; D008033:Limulus Test; D008070:Lipopolysaccharides / Q000032:analysis*; D009391:Nephelometry and Turbidimetry / Q000379:methods; D011897:Random Allocation; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D008070:Lipopolysaccharides; D003035:Cobalt