PubMed · 14891631
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A R ALBANESE. 1951-11-16. [Constrictive pericarditis; approach].. https://pubmed.ncbi.nlm.nih.gov/14891631/
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OBJECTIVES: A primary reason for premature failure of Class II composite restorations is recurrent decay at the gingival margin. The integrity of the gingival margin depends on the bond formed with dentine. Using scanning electron microscopy (SEM) and histomorphologic technique, the purpose of this study was to characterise the adhesive/dentine (a/d) bond in dentine sections from the dentinoenamel junction (DEJ) and the cementoenamel junction (CEJ) with commercial adhesives of varying hydrophobic/hydrophilic composition. MATERIALS AND METHODS: The occlusal 1/3 of the crown was removed from 20 human third molars, this exposed the surface used for the DEJ sections. The teeth were sectioned occluso-gingivally into equal halves: one-half representing the DEJ; the remaining half was sectioned 4mm deep to the exposed surface (CEJ). Each half was treated with the same adhesive. The teeth were randomly selected for treatment with Single Bond (SB, 3M) or Dentastic UNO (UNO, Pulpdent) using wet bonding technique as per manufacturers' instructions. Thin (3-5mum) sections of native a/d interfaces were cut and stained with Goldner's trichrome for light microscopic (LM) examination. Companion slabs were polished and acid-bleach treated, then analysed with SEM. RESULTS: DEJ sections: SB/dentine specimens had approximately 4mum exposed protein at the interface, UNO infiltrated the depth of the demineralised dentine and encapsulated exposed protein. CEJ sections: SB/dentine specimens had highly variable interface structure with localized exposed protein, UNO/dentine exhibited 3-5mum exposed protein at the interface. The quality of the interface was exaggerated and the above differences were not revealed based on SEM characterisation. CONCLUSIONS: As a result of adhesive phase separation, SB does not form structurally integrated a/d bonds at the DEJ or CEJ. The increased hydrophilic composition of UNO contributes to the formation of an integrated a/d bond at the DEJ, but structural differences and increased moisture leads to unprotected protein at the a/d interface in the CEJ sections. The inability of the SEM technique to reveal the complexity of the interface could be related to the modifications of the a/d interface caused by polishing and acid-bleach treatment.
OBJECTIVE: In 1997 a new source of potential polycyclic aromatic hydrocarbon (PAH) exposure was discovered: very high levels of (PAHs) and benzo-a-pyrene (BaP) were detected in household dust from former American Forces housing in Frankfurt am Main, Germany, built in 1955/1956. This contamination was caused by a parquet glue containing coal tar, the use of which was formerly a standard building practice in Germany. Children were considered to be at special risk for exposure to PAHs when playing on the floor via mouthing. Therefore, the children's symptoms and complaints were analysed for association with PAH contamination in parquet glue and household dust as well as with internal exposure to PAHs via determination of 1-hydroxypyrene in urine samples. PARTICIPANTS AND METHODS: Two hundred and eighty seven children <6 years of age living more than 12 months in the former US-housing estates are enrolled in this analysis, representing 22.3% of the children <6 years of age living there. Their spot urine samples were analysed for 1-hydroxypyrene. The level of BaP in parquet glue and in household dust was available in the homes of 215 and 212 children, respectively. There were no hints for differences in PAH contamination in parquet glue or in household dust of the participants' flats compared to the flats of the non responders. In 246 cases data on environmental tobacco smoke exposure at home was known as well. Data on symptoms and complaints observed by their parents during the preceding 12 months (1-year prevalence) were obtained using the ISAAC questionnaire (modified). RESULTS: The following 1-year prevalences were reported: 15% itching eczema in elbows, 10% itching and urticaria, 6% itching in the palate and throat, 20% sneezing and running nose or stuffed nose, 15% nosebleed; 25% wheezing, 42% dry cough, and 60% frequent infectious disease. No consistent associations between symptoms and BaP in parquet glue or in household dust or urinary levels of 1-hydroxypyrene in the children could be found. However, associations between symptoms and exposure to environmental tobacco smoke at home were to be seen, significant for dermal and bronchial symptoms. CONCLUSION: Informed about PAHs in parquet glue and household dust many parents demanded for total redevelopment of their flats. According to statistical evaluation of the children's symptoms, observed by their parents, no hints for an association with exposure via BaP in parquet glue or household dust were found. However, significant associations between symptoms and the exposure to environmental tobacco smoke were observed, especially bronchial and dermal symptoms. Therefore instead of redevelopment of flats with parquet glue containing coal tar, intensified information on the harmful effects of passive smoking in childhood seems to be mandatory.