Effects of ethanol on the rat brain: ultrastructural alterations in the temporal cortex and in the hippocampus

Male rats were submitted either to an oral alcohol intoxication or to chronological aging. Nervous morphometry shows that chronic alcohol consumption induces an increase in the proportion of neurons with dense cytoplasm and an increase of the synaptic cleft affecting principally synapses with spherical vesicles. The cerebrovascular morphometry revealed that the vascularity enhances with chronic alcohol consumption in young animal. The same enhancement is observed in aged animals showing thus a parallelism between alcoholised and aged animals.     

Bio-electrical impedance analysis for estimation of fat-free mass and muscle mass in cystic fibrosis patients

The nutritional status of cystic fibrosis (CF) patients has to be regularly evaluated and alimentary support instituted when indicated. Bio-electrical impedance analysis (BIA) is a recent method for determining body composition. The present study evaluates its use in CF patients without any clinical sign of malnutrition. Thirty-nine patients with CF and 39 healthy subjects aged 6–24 years were studied. Body density and midarm muscle circumference were determined by anthropometry and skinfold measurements. Fat-free mass was calculated taking into account the body density. Muscle mass was obtained from the urinary creatinine excretion rate. The resistance index was calculated by dividing the square of the subject's height by the body impedance. We show that fat-free mass, mid-arm muscle circumference and muscle mass are each linearly correlated to the resistance index and that the regression equations are similar for both CF patients and healthy subjects.     

Margin analysis of posterior composites in vivo

One of the major shortcomings of posterior composites is their tendency to shrink during polymerization. Thirty-three class II cavities were filled with Occlusin (OCC) (12), Coltène EX-D2 (CEX) (10), and Dispersalloy (AM) (11). The composites were placed in beveled, enamel-etched cavities by means of an incremental technique. One week and seven mo after placement, replicas were obtained and quantitatively analyzed in the SEM. The composites showed higher percentages of "excellent margin" (EM) (OCC, 70.6%; CEX-D2, 66.6%) than AM (49.2%) at baseline (p less than 0.01) and after seven mo (p less than 0.01). During the experimental period, the percentage of EM decreased by 10% for AM and OCC and by 14% for CEX-D2 (p less than 0.01). With the composites, an increase of "submargination" (SM) was found: OCC, 8.8%, and CEX-D2, 12.7%. An increase (11.2%) in margin fractures occurred for amalgam. Only OCC showed a low but significant increase (6%) in "marginal openings" (MO). This study confirms the inferior micromorphology of AM at the margins. The high amount of MO with the resin composites (16% after seven mo) indicates that, despite the complicated application technique, leakage of the restorations will occur. The margin analysis showed SM (OCC, 18%; CEX-D2, 21%) after seven mo, indicating severe wear. Class II amalgam restorations should not be replaced with the composites used in this study.     

Long-Term bacterial leakage along obturated roots restored with temporary and adhesive fillings

The aim of this study was to examine whether obturated roots combined with several adhesive and temporary filling materials can be bypassed by bacteria. Standardized cavities were coronally prepared into 130 straight roots mimicking clinical access cavities. After obturation the roots were assigned to six test and three control groups and coronally sealed with either Clearfil, CoreRestore, IRM, Ketac Fil, or a combination of IRM/wax or Ketac Fil/wax. The roots were then fixed between a top and a bottom chamber each. The top chamber contained soy broth with 108 Staphylococcus epidermidis colony-forming units/ml, and the bottom chamber contained sterile soy broth. For 1 yr the mounts were checked on a regular basis for turbidity in their bottom chambers indicating bacterial growth. After 1 yr only three samples from the CoreRestore group and two samples from the Clearfil group resisted leakage. At termination there was no significant difference in number of leaking samples among the groups. At the beginning of the experiment IRM performed worst. Between months 5 and 10 Clearfil showed the least leaking samples; for some months this was statistically significant compared with IRM or Ketac Fil.     

Margin quality of Class III and IV composites in vitro.

Polymerization shrinkage and thermal expansion/contraction of composites counteract marginal bonding. The purpose of this study was to determine the margin quality of Class III and IV microfilled and hybrid composite restorations placed with adhesive techniques. Two experiments were conducted. In experiment 1, small, beveled Class III cavities were prepared in 24 incisors. Twelve cavities were filled with an experimental microfilled composite (COMPAFILL) and 12 with a control microfilled material (DURAFILL). In experiment 2, standardized large, beveled Class IV cavities were prepared in 24 incisors. Twelve of these incisors were filled with DURAFILL and 12 with the hybrid composite HERCULITE XR. The teeth were stored in water for 21 days. Before and after the restorations were thermocycled (5 degrees C-55 degrees C), replicas were obtained for quantitative analysis in the SEM. Statistical analysis (non-parametric tests, p less than 0.05) revealed that the two microfilled materials behaved very well (greater than 95% excellent margins) in Class III restorations before being thermocycled. After the restorations were thermocycled, the margin quality of DURAFILL decreased to 90% excellence, due to the increase in restoration fractures. Thermocycling did not affect the margin quality in the Class IV cavities, and the hybrid composite showed superior margin qualities (89% excellent). Better margin qualities were obtained in Class III cavities. Class IV restorations showed more overhangs (12%) and submargination (6%) which were technique-related. In no cases were greater than 1% marginal openings found.     

Marginal adaptation of four tooth-coloured inlay systems in vivo.

This study investigates the margin quality of four different tooth-coloured inlay systems using computer-aided quantitative margin analysis under scanning electron microscopy. Three types of restorations involved chairside procedures using a commercial CAD-CAM apparatus: one type of inlay restoration was milled from preformed glass ceramic blocks, the other two inlay types were milled from preformed porcelain blocks. The fourth system was based on an experimental indirect composite inlay system. Each inlay type was luted with its respective dual-curing luting composite, which was supplied with the system. After 6 months of clinical service, all four systems revealed a significant percentage of submargination indicating occlusal wear of the luting composite. The porcelain inlays and the composite inlays luted with their respective experimental luting composite showed the best marginal adaptation. Luted glass ceramic inlays, in particular, suffered from a significantly higher percentage of inlay margin fractures (9 per cent) and marginal openings (4 per cent) than the other systems. A possible explanation is that the glass ceramic subsurface structure at the inlay-lute interface was weakened by etching with ammonium bifluoride.