Elution of residual monomers from dental composite materials.

AIM: This study was designed to determine the type and amount of the monomers leached from the different particle sizes of the composite materials. MATERIALS AND METHODS: Three different disk sizes (2, 4, 6 mm) prepared for each material group (Filtek Flow, Filtek A110, Filtek P60 and Filtek Supreme) were polymerised by LED and halogen light; the specimens were then placed in artificial saliva. The monomer release in 30 min and 24 hrs from the specimens was analyzed in HPLC calibrated for the monomer extracts before. RESULTS: TEGDMA release was detected in all material groups after 30 min and after 24 hrs. BisGMA and BisEMA were not determined in any groups and UDMA was detected only in Filtek Supreme. Significant differences in release of TEGDMA and UDMA were obtained between the different sizes of discs. Significantly high amount of TEGDMA and UDMA monomer release was obtained in LED than Halogen groups. Lower amount of monomer release was obtained in species of 30 min than 24 hrs. CONCLUSION: Data has revealed that the monomer release could be detected significantly high from the composite materials polymerized by a lower output curing light device; and higher elution of monomers was determined as the composite thickness has increased. Therefore, the clinical applications of composite materials and the type of curing units have very important effects on the success of restorations and in the decrease of potential side effects.

A study on neonatal factors and eruption time of primary teeth.

OBJECTIVE: The purpose of this study was to determine the time of the eruption of the first primary tooth (FPT) in infants and to assess the effects of neonatal factors on the timing of the eruption. BASIC RESEARCH DESIGN: The dental and medical records of healthy infants were reviewed to gather data on birth weight (BW), gestational age (GA), prenatal history, and the time of the eruption of the FPT. Additionally, the mothers of these infants were asked to identify their smoking habits and/or caffeine consumption during pregnancy through face-to-face interviews. The resulting data were statistically analysed with the Student's t, Tukey, and Pearson correlation tests. RESULTS: The mean eruption times (MET) for girls and boys were 7.25 +/- 2.47 and 7.07 +/- 1.66 months respectively (p > 0.05). The MET of the FPT in infants with a GA of less than 34 weeks, 34 to 37 weeks, or over 37 weeks were 8.0 +/- 2.0, 8.29 +/- 2.97, 6.93 +/- 1.87 months, respectively. The MET in infants with a BW of 1500 to 2500g was 8.28 +/- 2.28 months, while the MET for the infants with a BW of over 2500g was 6.99 +/- 1.94 (p = 0.014). CONCLUSION: A significant difference was found in the METs of infants with low and normal BWs. No significant differences were observed in the MET as related to other neonatal factors.