FE-SEM Evaluation of Dental Specimens Prepared by Different Methods forIn VitroContamination

Objective . To evaluate through FE-SEM the cleanliness and dentinal alterations promoted by different methods of dental sample preparation. Methods . Twenty-five human single-rooted teeth were used. The teeth were cleaned and autoclaved in wet medium and randomly divided into 5 groups ( n = 5), according to the preparation methods employed—control group: no solutions applied; group 1: cement removal and irrigation with 5.25% NaOCl  + 17 % EDTA for 4 minutes each; group 2: 17%  EDTA + 2.5% NaOCl (4 minutes ultrasonic bath); group 3: cement removal and 17%  EDTA + 5.25%  NaOCl + phosphate buffer solution + distilled water (10 minutes ultrasonic); group 4: 17%  EDTA + 5.25% NaOCl (3 minutes ultrasonic bath). Specimens were analyzed by field emission scanning electron microscope (FE-SEM), at 1500x magnification. Data were submitted to qualitative analysis according to a scoring system and submitted to Kruskal-Wallis test. Results . In ascending order, as to bind parameters, (i) cleanliness: control, group 2, group 3, group 5, and group 4, (ii) dentinal alterations: group 1, group 5, group 2, group 3, and group 4. Conclusion . The proposed protocol was suitable for subsequent microbiological contamination, because it showed less dentinal morphological alterations with increased removal of organic waste.