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Biomedical subjects

F Monticelli

Publications and source records attributed to F Monticelli.

8 recordsLinked to original sources

The adhesion between fibre posts and composite resin cores: the evaluation of microtensile bond strength following various surface chemical treatments to posts.

AIM: To evaluate the influence of various surface treatments to fibre posts on the microtensile bond strength with different composite resins. METHODOLOGY: A total of 110 fibre posts were randomly divided into five groups, according to the surface pre-treatment performed. Group 1: immersion in 24% H(2)O(2) for 10 min and silanization for 60 s; group 2: immersion in 10% H(2)O(2) for 20 min and silanization for 60 s; group 3: immersion in 4% hydrofluoric acid gel for 60 s and silanization for 60 s; group 4: silanization of the post surface for 60 s and application of the bonding agent G-Bond; group 5: silanization of the post surface for 60 s (control group). After treatment, two posts were randomly selected from each group to evaluate the morphological aspect of the post surface with scanning electron microscopy. The remaining posts in each group were divided into five subgroups of five posts each, which differed in the type of composite resin used for the core build-up. Post-core strength were calculated and the differences among experimental groups were analysed with two-way anova and the Tukey test (alpha = 0.05). RESULTS: The post-core strengths achieved in groups 1 and 2 were significantly higher (P < 0.05), than those of groups 3, 4 and 5. The post-core strength in the control group was significantly lower (P < 0.05) than all other groups. CONCLUSIONS: Hydrogen peroxide and hydrofluoric acid both modified the surface morphology of fibre posts and with silane, significantly enhanced the interfacial strength between them and core materials.

Acrylic Resins↗

Fatal pulmonary cement embolism following percutaneous vertebroplasty (PVP).

A case of fatal pulmonary embolism with acrylic cement occuring during a percutaneous vertebroplasty on account of a fracture of L1 is described. Autopsy confirmed the presence of large amounts of surgical cement in the paravertebral venous system and in the pulmonary arteries. This rare complication occurred because perivertebral venous cement migration was not recognized during vertebroplasty. To our knowledge, this is the first case of fatal pulmonary embolism caused by surgical cement following a percutaneous vertebroplasty.

Aged↗

Crossbow homicides.

A total of eight cases of homicide by crossbow are reported, including six intentional, assault-like killings and one hired killer. The bolts showed a high penetration capacity despite the rather low kinetic energy (<100 J): a field-tip traversed one upper arm and the thorax (36 cm) and two broadheads caused perforating injuries of the thorax (25-26 cm). This was due to the high sectional density and the split-like penetration mechanism. Wound morphology was especially important if the perpetrator had extracted the bolt, which occurred in half of the cases. The shape of the entrance wound depended on the type of arrowhead: broadheads produced star-shaped to triangular wounds, field-tips caused circular, oval or slit-like injuries. Foreign material from the arrowhead was found inside two injuries. In assaults, the crossbow was used to hunt the victim down from a short distance which does not require practice but still has the advantage of a distance weapon. However, immediate incapacitation occurred rarely so that additional violence was frequently applied. The noiseless character of the weapon explains why many victims were taken by surprise and why the corpses initially remained unnoticed. Crossbows can therefore be considered ideal weapons for man hunting and some were bought for the very purpose of the killing.

Adolescent↗

A one step procedure for luting glass fibre posts: an SEM evaluation.

AIM: To evaluate the ability of two luting procedures for bonding translucent fibre posts to form resin tags, adhesive lateral branches, and resin dentine interdiffusion zones (RDIZ). METHODOLOGY: Forty root filled teeth, extracted for periodontal reasons, were selected for the study. The teeth were randomly divided into four groups of 10 each. Group 1: One Step, light-cured (LC) 20 s + dual link resin cement (LC 20 s); group 2: One Step, not light-cured (NLC) + dual link resin cement (LC 30 s); group 3: One Step (NLC) + dual link resin cement (LC 60 s); group 4: One Step (NLC) + dual link resin cement (LC 90 sec). Forty translucent fibre posts (DT posts, RTD) were inserted. Then, root specimens were processed for scanning electron microscope (SEM) observations to assess the continuity of the RDIZ, the presence or absence of gaps and the density and morphology of resin tags using a four-step scale method. RESULTS: With all luting procedures the formation of a RDIZ occurred. However, the microscopic examination of adhesive interfaces revealed that the percentage of RDIZ was significantly higher in group 1 than in the other three groups (P < 0.05). Group 4 had a higher percentage of RDIZ than group 3, which in turn exhibited a greater percentage than group 2, but these differences were not statistically significant (P > 0.05). Resin tag formation was evident in all the groups. The characteristic reverse cone shape of resin tags was always noted in the coronal and middle third of all groups, and in the apical third of group 1. In the apical third a shorter length and a less uniform appearance of resin tags were noted in groups 2, 3 and 4. CONCLUSIONS: In this laboratory study, when bonding a translucent fibre post into a root canal, the luting procedure including light curing of the adhesive solution before the placement of the cement was more satisfactory, from a SEM standpoint, than the procedure involving the simultaneous curing of adhesive and cement (one step procedure).

Dental Bonding↗

In vivo and in vitro permeability of one-step self-etch adhesives.

Adhesive dentistry should effectively restore the peripheral seal of dentin after enamel removal. We hypothesize that non-rinsing, simplified, one-step self-etch adhesives are effective for minimizing dentin permeability after tooth preparation procedures. Crown preparations in vital human teeth were sealed with Adper Prompt, Xeno III, iBond, or One-Up Bond F. Epoxy resin replicas were produced from polyvinyl siloxane impressions for SEM examination. Dentin surfaces from extracted human teeth were bonded with these adhesives and connected to a fluid-transport model for permeability measurements and TEM examination. Dentinal fluid droplets were observed from adhesive surfaces in resin replicas of in vivo specimens. In vitro fluid conductance of dentin bonded with one-step self-etch adhesives was either similar to or greater than that of smear-layer-covered dentin. TEM revealed water trees within the adhesives that facilitate water movement across the polymerized, highly permeable adhesives. Both in vitro and in vivo results did not support the proposed hypothesis.

Acid Etching, Dental↗

Air rifle injury with an entrance through the nose: a case report and review of the literature.

A case of attempted homicide is reported where a 31-year-old woman was shot in the left nostril with a pellet from an air rifle. The projectile channel reconstruction showed penetration of the nasal septum, the maxillary and sphenoid cavities and the dura mater, with the pellet finally lodging in the anterior cranial fossa between the sinus cavernosus and the internal carotid artery. The patient was finally discharged from hospital in a good physical condition without any neurological symptoms. Although the muzzle velocity of the air rifle was within the legal limits, the present case demonstrates the potential lethality of air weapons considering the site of entrance of the pellet.

Adult↗

Cytokine pattern in patients with infections after liver transplantation.

Severe infections are the most frequent cause of death after liver transplantation. Determination of new parameters may increase the knowledge of pathophysiological mechanisms of infection. For this purpose, 81 patients with 85 liver transplants were monitored for various new parameters on a daily basis. Patients with severe infections (n = 10) were compared with patients with mild or asymptomatic cholangitis (n = 11) and with patients with an uneventful postoperative course (n = 37). One-year patient survival was 88.9%; in five patients, death was related to serious infections. Mean neopterin, soluble tumor necrosis factor-RII (sTNF-RII), and hyaluronic acid levels were significantly elevated in patients with serious infections compared with the other two groups (P < or = 0.01). A further increase in sTNF-RII and neopterin levels was observed in patients with lethal infections (P < or = 0.01 versus surviving patients with serious infection). An increase in neopterin levels was observed prior to severe infection, and in six of ten patients, this increase occurred as early as during the reperfusion period. Soluble TNF-RII and hyaluronic acid levels also increased significantly prior to severe infection. Interleukin (IL)-6, soluble intercellular adhesion molecule-1 (sICAM-1), and sIL-2R increased in patients with serious infection and cholangitis to a similar extent. As part of an overwhelming immune response, a significant increase in IL-6, sIL-2R, and also IL-1 beta levels occurred during the late phase of lethal infection (P < or = 0.01 versus surviving patients with serious infection). Routine monitoring of these parameters may improve current diagnostic tools and possibly lead to earlier detection of patients at risk after liver transplantation.

Biopterins↗