Evaluation of subcutaneous and alveolar implantation surgical sites in the study of the biological properties of root-end filling endodontic materials

Objective: The aim of this study was to compare two methodologies used in the evaluation of tissue response to root-end filling materials in rats. Material and Methods: Forty rats were divided into 4 groups: in Groups I and II (control groups), empty polyethylene tubes were implanted in the extraction site and in the subcutaneous tissue, respectively; in Groups III and IV, polyethylene tubes filled with ProRoot MTA were implanted in the extraction site and in the subcutaneous tissue, respectively. The animals were killed 7 and 30 days after tube implantation, and the hemi-maxillas and the capsular subcutaneous tissue, both with the tubes, were removed. Specimens were processed and evaluated histomorphologicaly under light microscopy. The scores obtained were analyzed statistically by the Kruskal-Wallis test (p<0.05). Results: There were no statistically significant differences between the implantation methods (p=0.78033, p=0.72039). It was observed that the 30-day groups presented a more mature healing process due to smaller number of inflammatory cells. Conclusions: The present study showed no differences in tissue responses as far as the implantation site and the studied period were concerned. Alveolar socket implantation methodology represents an interesting method in the study of the biological properties of root-end filling endodontic materials due to the opportunity to evaluate bone tissue response.

COLOR STABILITY of SEALED COMPOSITE RESIN RESTORATIVE MATERIALS AFTER ULTRAVIOLET ARTIFICIAL AGING and IMMERSION IN STAINING SOLUTIONS

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Colonisation of soft lining materials by micro-organisms

Objective:This study evaluated the in vitro adherence of pathogenic micro-organisms, Candida albicans, Staphylococcus aureus and Pseudomonas aeruginosa, to soft lining materials and their inhibitory effect on these micro-organisms.Materials and Methods:To measure adherence, specimens of Molloplast B and Ufi Gel P were inoculated [107 colony-forming units per millimetre (cfu/ml)] with TSB media containing the micro-organisms. To determine the number of micro-organisms in the 10-2-10-5 dilutions, 25 mu l of the suspension were transferred to plates of selective media. Colony counts of each specimen were quantified (cfu/ml). The surface roughness was measured with a perfilometer to assess the relationship between the adherence of micro-organisms and surface roughness of each material. For the inhibition test, specimens of materials were placed in agar plates inoculated individually with the micro-organisms. After 48 h, the inhibition zones around the specimens were measured.Results:None of the materials exhibited inhibition zones. The number of cfu/ml of S. aureus and P. aeruginosa were significantly greater than C. albicans for both materials. The Ufi Gel P exhibited greater adherence of C. albicans than Molloplast B. No correlation was observed between the adherence of micro-organisms and surface roughness.Conclusion:The surface roughness of the materials is not the only factor governing micro-organism adherence.