Evaluation of antibiotic prophylaxis in reducing postoperative infection after mandibular third molar extraction in young patients

PURPOSE

This study evaluated the influence of antibiotic prophylaxis on postoperative complications after inferior third molar removal in young patients.

PATIENTS AND METHODS

We extracted 59 mandibular third molars from 59 patients with a mean age of 15 years (range, 12-19 years). The patients were included in the study when radiographs at the time of surgery showed that only the crown of the tooth germ was formed. Patients were randomized into 2 groups, the test group and the control group. The test group received 2-g amoxicillin tablets 1 hour before surgery, and the control group received no antibiotic therapy. The test group included 32 patients, 20 of whom were female and 12 were male; the mean age was 15 years. The control group included 27 patients, 12 of whom were female and 15 were male; the mean age was 15 years. Postoperative complications such as pain, swelling, wound infection, and fever were recorded by use of a questionnaire completed by the patient for the week after the extraction. Suture removal and questionnaire evaluation were performed by a surgeon who did not know the preoperative regimen.

RESULTS

The mean operating time was 34 minutes in the control group and 31 minutes in the test group. This difference was not significant. In the test group there was a statistically significant reduction of postoperative pain in the 7 days after the extraction, and the patients had a consistent minor consumption of analgesics. Swelling was always present in the control and test groups in the postoperative week, but in the test group it was a minor sequela and was absent in 2 patients. Wound infection was a sequela reported in 4 patients in the control group and in 1 patient in the test group; this difference was statistically significant (P < .01). Fever was present in 2 patients in the control group and in 1 patient in the test group; this difference was not statistically significant.

CONCLUSIONS

A statistically significant difference was found between patients receiving preoperative amoxicillin and the control group in the incidence of postoperative pain, fever, and wound infection. Another important finding was the statistically minor consumption of analgesics in the test group in the postoperative week.

Connection between Boson peak and elastic properties in silicate glasses

Inelastic neutron, light, and x-ray scattering are used to investigate the vibrational density of states (VDOS) and the elastic properties of a sodium silicate glass as a function of temperature. The elastic moduli show the frequency and temperature dependence typical of anharmonic effects. The measured VDOS spectra, up to and including the excess vibrational density at the boson peak, scale with the Debye level only if this is calculated from the high-frequency values of the elastic constants. This emphasizes that conclusions on the relation between VDOS and elastic properties can be drawn only if anharmonic and relaxational effects are properly taken into account.

High frequency dynamics in liquids and supercritical fluids: A comparative inelastic x-ray scattering study

The microscopic dynamics of four prototype systems (water, ammonia, nitrogen, and neon) across the critical temperature has been investigated by means of high-resolution inelastic x-ray scattering. The experimental line shape has been described using a model based on the memory function formalism. Two main relaxations, the thermal and the structural one, were observed in all the investigated systems. We found that the microscopic mechanism driving the structural relaxation clearly changes, being mainly governed by intermolecular bond rearrangements below the critical temperature and by binary collisions above it. Moreover, we observed that the relative weight of the thermal relaxation systematically increases on approaching the critical temperature, thus allowing for the observation of a transition from an adiabatic to an isothermal regime of sound propagation. Finally, we found the presence of an additional instantaneous relaxation, likely related to the coupling between collective vibrational modes and intramolecular degrees of freedom.

Raman-scattering measurements of the vibrational density of states of a reactive mixture during polymerization: effect on the boson peak

Raman-scattering measurements are used to follow the modification of the vibrational density of states in a reactive epoxy-amine mixture during isothermal polymerization. Combining them with Brillouin light and inelastic x-ray scattering measurements, we analyze the variations of the boson peak and of the Debye level while the system changes from liquid to glass upon increasing the number of covalent bonds among the constituent molecules. The shift and intensity variation of the boson peak are explained by the modification of the elastic properties throughout the reaction, and a master curve for the boson peak can therefore be obtained. Surprisingly, bond-induced modifications of the structure do not affect this master curve.

Mandibular third molar removal in young patients: an evaluation of 2 different flap designs

PURPOSE

To evaluate the influence of 2 different flap designs on periodontal healing and postoperative complications, after inferior third molar removal in young patients.

PATIENTS AND METHODS

Twenty-four mandibular third molars were extracted from 12 patients with an average age of 16 years. Patients were included in the study when radiographs at the time of surgery showed that only the crown of the germ was formed. Each patient underwent 2 extractions, using a triangular flap on one side and an envelope flap on the other. Periodontal probing was recorded at the preoperative visit, and 7 days, 3 months, and 6 months after extraction. Postoperative complications were recorded using a questionnaire completed by the patient for the week after the extraction.

RESULTS

The examination performed 7 days after the extraction demonstrated a deeper probing depth in all teeth examined. This increase was statistically greater (P < .05) for the first and second molars when an envelope flap was used. After 3 months, the probing depths returned to preoperative values. No significant differences were seen between the 2 flap designs when postoperative complications were considered. The average operating time was 30.66 minutes with the triangular flap, versus 35.66 minutes with the envelope flap. This difference was not significant. After 6 months, the 2 flap designs resulted in no difference in periodontal healing or complications, but 30% of the surgical extractions resulted in a debilitating postoperative period for the patients treated.

CONCLUSIONS

Although we observed statistically significant differences in probing depth between triangular and envelope flaps 7 days after the extraction of third molars with no root development, this was not important from a clinical perspective, because periodontal healing at 3 and 6 months was comparable. We believe that this is also the case with the extraction of third molars with fully formed roots. Another important finding was the presence of a debilitating postoperative period in most of the patients who underwent extraction, contrary to the beliefs of many surgeons.

Zero sound mode in normal liquid 3He

Inelastic x-ray scattering has been utilized to study the elementary excitations of normal liquid 3He at the temperature T=1.10+/-0.05 K and saturated vapor pressure in the wave vector range 0.15<or=Q<or=3.15 A(-10. The present data provide direct information on the zero-sound mode in the mesoscopic wave vector range where it was expected to decay into particle-hole excitations. The obtained results show no evidence of such a decay: the zero-sound mode remains well defined in the whole explored wave number range, thus witnessing a continuous transition of the atom dynamics from the collective to the single particle regime similarly to what is usually found in simple liquids.

Liposome-incorporated Grb2 antisense oligodeoxynucleotide increases the survival of mice bearing bcr-abl-positive leukemia xenografts

We previously demonstrated that liposome-incorporated antisense oligodeoxynucleotide specific for the grb2 mRNA (L-Grb2) inhibited Grb2 protein expression and the proliferation of bcr-abl-positive leukemia cell lines. To determine whether L-Grb2 has the potential of being a therapeutic modality against bcr-abl-positive leukemia, we studied the tissue distribution of L-Grb2 in normal mice before studying its effects in mice bearing bcr-abl-positive leukemia xenografts. L-Grb2 was widely distributed in the body. The highest tissue concentrations of L-Grb2 were found in the spleen and liver, which are the organs where the tumor mass of bcr-abl-positive leukemia is mainly found. At 4 h post-injection, the amount of L-Grb2 detected per g of tissue was 64 microg in spleen and 50 microg in liver. Intravenous injection of bcr-abl-positive 32D mouse leukemia cells into radiated NOD/scid mice caused a lethal leukemia syndrome; we determined whether L-Grb2 could prolong the survival of mice bearing such xenografts. One day after leukemia cell inoculation, mice received twice weekly intravenous injections of L-Grb2. At an injection dose of 15 mg of L-Grb2 per kg of mouse body weight, 80% of mice treated with L-Grb2 survived to 48 days (end of study) whereas 0% of mice treated with the same dose of liposomal control oligonucleotide survived; the mean survival duration of these groups was 44 and 20 days, respectively. Our data indicate that L-Grb2 prolonged the survival of mice bearing bcr-abl-positive leukemia xenografts. L-Grb2 may be used as a novel cancer therapeutic modality.

[The historical-scientific foundations of thalassotherapy: state of the art]

Throughout the ages the interest in the use of sea water in medicine has fluctuated from century to century and from nation to nation. In this paper, the historical development of sea medicine from the ancient Egyptians until the 20th century is given. The medical world has viewed it with different opinions, from very enthusiastic to extremely critical, and from beneficial to harmful. In the last decades, thalassotherapy is receiving renewed attention from many medical specialties and health tourists. The aim of this review is that of offer an update on the real therapeutic possibility of the thalassotherapy. However, the exact therapeutic potential of thalassotherapy still remains largely unknown. Better and more profound scientific evidence for its efficacy is therefore warranted, in particular for its effects on the musculoskeletal system and skin. The main researches belong to the activity of thalassotherapy and the clinic outcomes, namely in osteoarthritis patients, were referred.

High-frequency dynamics of liquid and supercritical water

The dynamic structure factor S(Q,omega) of water has been determined by high-resolution inelastic x-ray scattering (IXS) in a momentum (Q) and energy (E) transfer range extending from 2 to 4 nm{-1} and from +/-40meV . IXS spectra have been recorded along an isobaric path (400bar) in a temperature (T) interval ranging from ambient up to supercritical (T>647K) conditions. The experimental data have been described in the frame of the generalized hydrodynamic theory, utilizing a model based on the memory function approach. This model allows identifying the active relaxation processes which affect the time decay of density fluctuations, as well as a direct determination of the Q , T , and density (rho) dependencies of the involved transport parameters. The experimental spectra are well described by considering three different relaxation processes: the thermal, the structural, and the instantaneous one. On approaching supercritical conditions, we observe that the microscopic mechanism responsible for the structural relaxation is no longer related to the making and breaking of intermolecular bonds, but to binary intermolecular collisions.

Structural and collisional relaxations in liquids and supercritical fluids

The dynamic structure factor S(Q,omega) of both associated (water and ammonia) and simple fluids (nitrogen and neon) has been determined by high-resolution inelastic x-ray scattering in the 2-14 nm(-1) momentum transfer range. A line-shape analysis with a generalized hydrodynamic model was used to study the involved relaxation process and to characterize its strength and time scale. We observe that in the liquid phase such a process is governed by rearrangements of intermolecular bonds, whereas in the supercritical region it assumes a collisional nature.

Non-invasive assessment of airway inflammation in ship-engine workers

Smoking is harmful for respiratory function. In young to middle-aged men the damage is insidious and difficult to demonstrate. The respiratory impairment could increase under specific stressful conditions in the professional environment. On the hypothesis that exhaled markers are useful for assessing airway susceptibility to inhaled irritants, we measured exhaled markers and lung function in smoking and non-smoking engine-driver military coastguards before and after a patrol at sea. Eighteen men, mean age 39 yrs (range 23-58 yrs), 8 smokers, underwent spirometry, exhaled and nasal nitric oxide (eNO, nNO), exhaled carbon monoxide (CO) and exhaled breath condensate (EBC) for measures of hydrogen peroxide (H2O2), leukotriene B4 (LTB4), proteins (Prots), 8-isoprostanes (8-IsoPs), nitrite (NO2-) and nitrosothiols (RS-NOs) at baseline and after an 8-hour patrol navigation on board small, high-speed diesel-powered ships. At baseline, the smokers showed higher middle flows and CO levels, lower eNO and nNO than non-smokers, but similar levels of EBC markers; geometric means (95% confidence interval), CO: 23.6 (14.5 to 38.3) vs. 3.5 (2.5 to 5.3) ppm; eNO: 7.9 (4.8 to 12.9) vs. 26.7 (15.7 to 45.5) ppb, p=0.000. After navigation, Prots, 8-IsoPs and RS-NOs (but not lung function variables or other markers) significantly increased only in smokers; baseline vs post-navigation RS-NOs: 0.27 (0.11 to 0.65) vs. 1.30 (0.58 to 2.89) micromol, p=0.012. The respiratory consequences of a stressing environment in engine-driver military coastguards who actively smoke are better assessed by measuring EBC markers than by eNO, nNO or lung function. By increasing airway inflammation from oxidative-stress, tobacco smoking appears to interact with other chemical or physical factors elicited during sea navigation. Precisely what these factors are deserves further investigation.

Extra-laryngeal manifestations of gastro-oesophageal reflux

Of the various otorhinolaryngological disorders for which it has been recognized that gastro-oesophageal reflux is a possible causal or associated aetiological factor, those manifestations localized in the rhino-sinus and auricular district are certainly the "least studied". Herein, therefore, these manifestations are described, focusing on the physio-pathological aspects and the more important pathogenic hypotheses of the cough, as well as other lung manifestations.

Effect of densification on the density of vibrational states of glasses

We studied the effect of densification on the vibrational dynamics of a Na(2)FeSi(3)O(8) glass. The density of vibrational states (DOS) has been measured using nuclear inelastic scattering. The corresponding changes in the microscopic, intermediate-range, and macroscopic properties have also been investigated. The results reveal that, in the absence of local structure transformations, the Debye level and the glass-specific excess of vibrational states above it have the same dependence on density, and the evolution of the DOS is fully described by the transformation of the elastic medium.

Coherent peaks and minimal probing depth in photoemission spectroscopy of Mott-Hubbard systems

We have measured hard x-ray photoemission spectra of pure vanadium sesquioxide (V(2)O(3)) across its metal-insulator transition. We show that, in the metallic phase, a clear correlation exists between the shakedown satellites observed in the vanadium 2p and 3p core-level spectra and the coherent peak measured at the Fermi level. Comparing experimental results and dynamical mean-field theory calculations, we estimate the Hubbard energy U in V(2)O(3) (4.20+/-0.05 eV). From our bulk-sensitive photoemission spectra we infer the existence of a critical probing depth for investigating electronic properties in strongly correlated solids.

Reflectance measurements and optical constants in the extreme ultraviolet-vacuum ultraviolet regions for SiC with a different C/Si ratio

Reflectance versus incidence angle measurements have been performed from 5 to 152 nm on samples of SiC with a different C/Si ratio deposited with rf magnetron sputtering. The optical constants of the material at different wavelengths have been determined by using a curve-fitting technique of reflectance values versus incidence angle. Complementary measurements of the incident beam polarization, film thickness, surface roughness, and stoichiometry were performed to complete the analysis of the samples.

Bond-induced ergodicity breakdown in reactive mixtures

We have studied by inelastic x-ray scattering, at wave vectors 1 nm < or =q< or =15 nm(-1), the high-frequency dynamics of epoxy-amine mixtures as the monomers irreversibly polymerize. We find that chemical bonding, while inducing molecular ordering on a mesoscopic length scale, also efficiently realizes the mechanism of dynamical arrest described by the mode-coupling theory, as manifested by a cusp singularity in the behavior of the nonergodicity factor as a function of the number of chemical bonds. These results confront positively the mode-coupling theory with a new control parameter.

Density of vibrational states of a hyperquenched glass

The vibrational density of states of a hyperquenched and an annealed glass has been measured using nuclear inelastic scattering. The hyperquenched sample shows a higher number of vibrational states in the low-energy region with respect to the annealed glass. It reveals, however, lower density and sound velocity and, therefore, smaller Debye energy. After rescaling the energy axes in Debye energy units and area renormalization, the density of states of both samples becomes identical. Thus, the effect of quenching is described by the transformation of the continuous medium.