Ferric sulphate alterations on primary dentin and the adhesive interface.

PURPOSE: The purpose of this study was to test the hypothesis that the pulp medication ferric sulphate (FS) may remain on primary dentin, affecting its microchemical structure and the bond strength of adhesives to primary dentin. MATERIALS AND METHODS: The effects of FS and pre-bonding conditioning (37% phosphoric acid [PA] for 15 s or a self-etching primer, with or without the use of 2% chlorhexidine [CHX]) on FS-treated primary dentin were characterized using optical microscopy with Masson's and Perls' stains, variable-pressure SEM/energy-dispersive x-ray spectroscopy (VP-SEM/EDS), Fourier transform infrared spectroscopy (FT-IR), and x-ray diffraction. Ferric sulphate was applied for 30 s or 1 h for microchemical analysis. The adhesive interface and the bond strength were studied by VP-SEM/EDS and the µTBS test (1 mm2 bars, crosshead speed 0.5 mm/min), respectively. The study groups were: etch-and-rinse (E&R, Excite) adhesive (group 1); FS+E&R (group 2); FS+CHX+E&R (group 3); self-etching (SE, Adper Scotchbond) adhesive (group 4); FS+SE (group 5); FS+CHX+SE (group 6). RESULTS: Ferric sulphate application produced demineralization, gypsum formation, and adsorption of Fe on the dentin surface, and it modified the collagen structure of primary dentin. There were no effects of FS on bond strength of the tested etch-and-rinse adhesive system. FS slightly reduced the bond strength between the primary dentin and the SE adhesive, and the values were not restored by CHX (group 4 = 17.58 ± 5.52 MPa > group 5 = 14.26 ± 7.08 MPa = group 6 = 13.96 ± 4.87 MPa). CONCLUSIONS: Ferric sulphate alters the microchemical structure of primary dentin and can impair the adhesive strength of some self-etching adhesives.

[Outbreak of meningitis caused by echovirus type 30]. / Brote epidémico de meningitis por echovirus tipo 30.

OBJECTIVES: In the cold months of 1994-1995, we detected in our hospital an epidemic outbreak of acute enteroviral meningitis caused by echovirus type 30 (Echo 30). Until now, these outbreaks of viral epidemics had not been detected in Spain. PATIENTS AND METHODS: We reviewed retrospectively 46 clinical histories of patients who were admitted to our hospital between September 1994 and January 1995 with the diagnosis of acute lymphocytic meningitis, analyzing the clinical outbreak, epidemiological and laboratory characteristics, and how the outbreak spread. RESULTS: Regarding the patients, there was a prevalence in males, with an average age of 6 years and a range of 2 to 13 years of age. The most constant symptom was severe frontal headache, with signs of meningitis in only 50% of the cases. In the CSF, we found a predominance of PMN in the differential cell count in 63% of the cases, with the time of evolution before spinal puncture less than 24 hours in the majority of the patients. Viral cultures were performed on CSF, stool and throat scrapings in 16 patients with Echo 30 being isolated in 15 cases, which suggests 32.6% of the total cases. CONCLUSIONS: We detected in our environment an epidemic outbreak of viral meningitis caused by an agent not found previously in Spain, which presented epidemiological, clinical and laboratory characteristics similar to those reported in the literature. Its appearance during the cold months contrasts to what normally occurs.