Glycerol salicylate-based containing α-tricalcium phosphate as a bioactive root canal sealer.

The use of bioactive materials instead of inert materials to fill the root canal space could be an effective approach to achieve a hermetic seal and stimulate the healing of periapical tissues. The purpose of this study was to develop and characterize an endodontic sealer based on a glycerol salicylate resin and α-tricalcium phosphate (αTCP) at physical and chemical properties. Different sealers were formulated using 70% of a glycerol salicylate resin and 30% of a mixture of calcium hydroxide and αTCP (0, 5, 10, or 15%, in weight). Sealers formulated were characterized based on setting time, in vitro degradation over time, pH, cytotoxicity, and mineral deposition. Sealers presented setting time ranging from 240 to 405 min, and basic pH over 8.21 after 28 days. Higher αTCP concentration leads to sealers with low solubility. Cell viability after 48 h in direct contact with sealers was similar to a commercial sealer used as reference. The 10% and 15% αTCP sealers exhibited a calcium-phosphate layer on the surface after immersion in water and SBF for 7 days. Glycerol salicylate sealers with 10% and 15% α-tricalcium phosphate showed reliable physical-chemical properties and apatite-forming ability.

Association of mannose-binding lectin 2 gene polymorphic variants with susceptibility and clinical progression in systemic lupus erythematosus.

OBJECTIVES: This study investigates the role of mannose-binding lectin (MBL) in susceptibility and clinical expression of systemic lupus erythematosus (SLE), through the analysis of promoter region and exon 1 polymorphisms of the MBL2 gene. METHODS: We analysed 325 SLE patients from the Hospital de Clínicas de Porto Alegre and 344 controls. All individuals were grouped according to ethnic origin. Genotyping of the promoter and exon 1 variants were performed by PCR-SSP and PCR-RFLP, respectively. Polymorphisms frequencies between patients and controls were compared by Chi-square or Fisher's exact tests. RESULTS: A statistically significant difference was observed among the frequencies of both promoter haplotypes (p=0.005) and haplotypic combinations (p=0.004) in African-derived patients, with a higher incidence of HY haplotype and LY/HY combination in SLE patients when compared to controls. These results showed a tendency to higher frequencies of genotypes related to high MBL levels in African-derived patients. A joint analysis of data from the promoter and exon 1 polymorphisms showed an increased frequency of genotypes conferring a deficient of MBL levels in European-derived patients (p<0.001). CONCLUSIONS: Our data suggest a possible influence of MBL deficiency in SLE European-derived although we did not observe any involvement of MBL2 variants in SLE clinical progression. The conflicting results shown by the analysis of patients grouped by ethnicity emphasise the need for studies considering this variable.