Clinical outcome and bone healing of implants placed with high insertion torque: 12-month results from a multicenter controlled cohort study.

This study evaluated the clinical outcome and the crestal bone resorption of implants placed with high insertion torque (up to 80 N cm). 102 patients were treated with 156 tapered implants. 42 implants (control group) presented insertion torque between 30 and 45 N cm (mean=37.4 SD 8.2). 114 implants (experimental group) were placed with insertion torque between 50 and 80 N cm (mean=74.8 SD 7.9). All implants were early loaded after 2 months. Peri-implant marginal bone levels were assessed immediately after surgery, and at 6- and 12-month follow up examinations. At the 12-month follow up all implants were clinically stable. After 12 months, patients in the experimental group lost an average of 0.41 mm (CI 95% 0.522; 0.263) of crestal bone compared with 0.45 mm (CI 95% 0.561; 0.286) for those in the control group. There were no significant differences between the two groups. No direct or inverse relationship was observed between the insertion torque values and crestal bone resorption. The results show that the use of high insertion torque (up to 80 N cm) did not prevent osseointegration and did not increase bone resorption around tapered implants early loaded up to 1 year after implant placement.

Low prevalence of human papillomavirus infection in the healthy oral mucosa of a Northern Italian population.

BACKGROUND: Oral cancer is the sixth most common malignancy in developed countries, representing almost 3% of malignant tumors. Tobacco use and alcohol consumption are well-established risk factors. However, the observation that most patients with oral cancer have not been exposed to these risk factors suggests that additional causes may promote oral carcinogenesis. A link has been suggested between human papillomavirus (HPV) and oral cavity cancer but the significance of HPV contribution to oral carcinogenesis as well as the prevalence of HPV infection in normal oral cavity mucosa remains debated. METHODS: In this study, the prevalence of oral HPV infection was evaluated in 81 randomly selected Northern Italian subjects with clinically normal oral mucosa using a nested PCR on DNA extracted by oral smears. RESULTS AND CONCLUSIONS: No HPV-related lesions were detectable in any of the smears analyzed by cytological approach. nPCR identified HPV DNA in only one (1.2%) of the specimens obtained from clinically healthy oral mucosa and subsequent characterization assigned the positive case to HPV type 90. These data suggest that the incidence of HPV infection in the healthy population might be very low and that other risk factors are likely responsible to promote oral carcinogenesis.

Expression of alpha-dystroglycan correlates with tumour grade and predicts survival in oral squamous cell carcinoma.

AIMS: Dystroglycan (DG) is a non-integrin adhesion molecule connecting the extracellular matrix to the actin cytoskeleton. Decreased expression of DG has been reported in several human cancers and related to tumour aggressiveness. METHODS: Expression of the alpha-DG subunit was evaluated by immunostaining in a series of oral squamous cell carcinoma (OSCC) and its relation with traditional prognostic indicators and with the clinical outcome of the patients was evaluated. RESULTS: Alpha-DG expression was easily detected in normal epithelium with a mean percentage of positive cells >80% but was undetectable in a significant fraction (59%) of OSCC. Loss of alpha-DG staining correlated with higher tumour grade (p = 0.04) and stage (p = 0.01), with nodal involvement (p = 0.001) and with an increased risk of recurrence (p = 0.002) and death (p = 0.004) in a univariate analysis, but it was not confirmed as an independent predictor of clinical outcome in a multivariate analysis. CONCLUSIONS: Loss of alpha-DG expression, which corresponds to loss of a functional DG complex, is a frequent event in human OSCC. Further studies are warranted on the role of this molecule in the entire multistep process of oral squamous tumorigenesis.

Halitosis: a stomatological and psychological issue.

It can be stated that halitosis is located on the ridge connecting dentistry, oral medicine, parodontology and psychology. It represents, at the same time, the manifestation of an organic malfunctioning of the oral apparatus, and a problematic element for the individual and his/her relational life. A smelly emanation comes into conflict with the wish to attract, to please, to seduce. The attitudes towards the possibility to suffer from bad breath have two typical opposite expressions, which share the common characteristic that many are bad judges of one's own breath. The dentist, in fact, is frequently involved in the management of patients who believe they have bad breath problems, which in reality are non-existent (pseudo-halitosis), and, more often, of patients who are not aware they have an halitosis condition, and who are not inclined to accept it (denied halitosis). Generally, the most adequate and suitable option is that of communicating to the unaware patient the existence and the nature of the problem. What is said, and especially the way of saying it, may play an important role in patient's acceptance of the information without producing, or reducing to a minimum, the undesirable side effects on the patient-professional relationship, and on the personal dynamics of the patient him/herself. A useful procedure is provided by employing a pre-visit questionnaire, that may suitably ask many different questions about relevant dental and mucosal aspects, for instance, dental complaints, the frequency of toothbrushing and flossing, gum bleeding, and about psychological aspects, such as dental anxiety, and degree of satisfaction as regards one's oral condition, in order to solve or alleviate the patient's problem, avoiding unnecessary personal discomfort and, at the same time, providing competent and effective professional help. Strategies for communicating in an effective way, in order to properly face both the somatic and the psychological aspects, are proposed. A questionnaire (Halitosis Questionnaire - HQ) is also provided, to facilitate the assessment and the management of the halitosis issue.

Effects of photoacoustic measurements on a nanostructured ZnSe mechanically alloyed.

Zinc-blende ZnSe powder, with particles containing nanometric grains, was prepared using the mechanical alloying technique, from an equiatomic mixture of elemental Zn and Se powders. An important interfacial component was observed in the as-milled powder, which affects its thermal and optical properties. In order to obtain a high-quality zinc-blende ZnSe powder an annealing process was applied. The structural properties of both as-milled and annealed powders were characterized by an x-ray diffraction technique. The effects of defect centers on the optical band gap of both as-milled and annealed zinc-blende ZnSe powders were studied through optical absorbance measurements. The results showed a substantial broadening and a shift of the band gap energy to lower values in the as-milled powder, while for the annealed sample no effects were observed. For the annealed sample, the measured band gap energy value is in good agreement with those reported in the literature. A sequence of photoacoustic absorption measurements of the as-milled ZnSe sample showed that the absorbed energy promotes a structural relaxation. This relaxation causes a change in the heat transfer mechanism from thermal diffusion to thermoelastic bending and a reduction in the thermal diffusivity values. Similar measurements of the annealed nanostructured ZnSe sample showed the thermal diffusivity value to have a high degree of stability, and to be in good agreement with values reported in the literature.

The pressure-induced phase transition of mechanically alloyed nanocrystalline GaSb.

Ga K-edge energy dispersive x-ray absorption spectroscopy and Raman spectroscopy measurements were employed to follow the pressure-induced semiconductor-metal phase transition of nanocrystalline GaSb produced by mechanical alloying up to 26 GPa. The results showed a slight increase of the phase transition pressures for both as-milled (8 GPa) and annealed (10 GPa) GaSb samples, as compared to that for the bulk one. The extended x-ray absorption fine structure analysis of the zinc blende (ZB) pressure domain (<10 GPa) showed that the microscopic compressibility of the bonds in the as-milled/annealed samples is higher/lower than the crystalline bulk modulus (56 GPa). The comparison between x-ray absorption near edge structure regions of the spectra and multiple scattering calculations suggests that the ZB structure evolves to a short-range chemically ordered ß-Sn structure for pressures as high as 8 GPa. Raman measurements confirm the semiconductor-metal phase transitions of ZB-GaSb between 8 and 11 GPa for both as-milled and annealed samples, showing that the semiconductor character was not recovered on releasing the pressure down to 3.9 and 1.8 GPa, indicating a very strong hysteresis effect (or even irreversible transitions). The well-known transverse effective charge reduction with pressure was also observed. Furthermore, resonance behaviour is clearly seen for transverse optical phonons and the resonance maxima peak occurs at about 1.2 GPa, corresponding to 2.11 eV in the E(1) scale, smaller by 0.3 eV than the incident photon energy.

Structural and photoacoustic studies of mechanically alloyed Ga(40)Sb(38)Se(22) powder.

GaSb, GaSe and Ga(2)Se(3) alloys were produced by the mechanical alloying technique. Their structural, thermal and optical properties were studied. Some of the results obtained have been reported in some papers referenced here. As an extension to those studies, some mixtures of elemental Ga, Sb and Se powders are now being investigated. Starting from a mixture with nominal Ga(62)Sb(27)Se(11) composition, 9 h of milling resulted in a final product with Ga(40)Sb(38)Se(22) composition and containing nanometric cubic GaSb and an amorphous GaSe phase. Part of this as-milled sample was annealed in order to study the amorphous-crystalline phase transformation. The crystalline cubic GaSb, hexagonal and rhombohedral GaSe phases form the measured x-ray diffraction (XRD) pattern for the annealed sample. The structural and thermal properties of both as-milled and annealed samples were studied by x-ray diffraction, differential scanning calorimetry and photoacoustic spectroscopy (PAS) techniques. We observe that the thermoelastic bending contribution is dominant in the PAS signal for both as-milled and annealed samples. The thermal diffusivity value was calculated for both samples by fitting the PAS signal phase.

A comparative study between different techniques in non-surgical periodontal treatment.

AIM: This study was carried out to compare a conventional manual instrumentation with an ultrasonic technique (Odontoson M) in scaling and root planing periodontal treatment. The effects of subgingival irrigation with 10% iodised solution in association with Odontoson M were studied. METHODS: Sixty patients were selected: they were suffering from adult periodontitis, aged between 35 and 65 and non-smokers. They were randomly divided into 3 groups (Gs1, Gs2, Gs3). Gs1 was treated with curettage using Gracey curettes, Gs2 was treated with scaling and root planing using Odontoson M, while in Gs3 scaling and root planing with Odontoson M irrigated with a 10% iodised solution were performed. Clinical parameters (probing depth, bleeding on probing, dental mobility, loss of attachment level) were measured before treatment (T0), after 30 days (T1), after 90 days (T2) and after 120 days (T3). RESULTS: No statistical significant differences between Gs1 and Gs2 were observed. The improvement of clinical parameters in Gs3 was greater and statistical significant differences with other groups treated were recorded. CONCLUSIONS: There are no significant differences between the effectiveness of scaling and root planing with manual instruments and with Odontoson M. The 10% iodised solution used such as topic antiseptic carries out greater effects in not surgical periodontal treatments.

The importance of splinting of teeth in the therapy of periodontitis.

AIM: The deep periodontal disease often leads to dental mobility with further aggravation of the symptomatology. The aim of the paper is to verify the importance of splinting of teeth in the therapy of periodontitis on the basis of parameters commonly studied [probing depth (PD), bleeding on probing (BOP), plaque index], and the role of the occlusal trauma as primary factor or second leading factor in periodontal diseases. METHODS: Thirty patients suffering from periodontitis have been treated with the splinting of teeth, neither preceded nor followed from topical and systemic pharmacological therapy, nor from surgical or non surgical treatment of the periodontal tissues involved. During the 4 visits provided by the study, T0 (0 days), T1 (30 days), T2 (90 days) and T3 (180 days), PD, BOP and plaque index have been estimated. RESULTS: From the comparison of the T0 PD and BOP with the T3 PD and BOP, a significant improvement of these parameters is observed (P<0.05). CONCLUSION: On the basis of the clinical data obtained in this research, the authors suggest that the therapy by means of splinting improves the prognosis of teeth affected by periodontal disease; occlusal trauma and dental mobility cause the aggravation of periodontal lesions.

Mechanical alloying: a pressure induced reaction for obtaining zinc blende GaSb and multiphase states.

The cubic zinc blende GaSb phase was produced by a mechanical alloying technique, which is a solid state route based on the action of non-hydrostatic pressures. The thermal stability of this phase was tested using the differential scanning calorimetry technique and, in order to clarify the results, an annealing process was performed. Comparing x-ray diffraction patterns for as-prepared and annealed samples, the improvement in crystallinity of the cubic phase and Sb segregation and/or crystallization can be easily seen. Optical phonons frequencies were measured for both as-milled and annealed samples by means of the Raman spectroscopy technique. Raman profiles of as-milled samples showed typical zinc blende GaSb optical modes and revealed new features that can be associated with multiphase states.

Reverse Monte Carlo simulations, Raman scattering, and thermal studies of an amorphous Ge30Se70 alloy produced by mechanical alloying.

The short- and intermediate-range orders of an amorphous Ge30Se70 alloy produced by mechanical alloying were studied by reverse Monte Carlo simulations of its x-ray total structure factor, Raman scattering, and differential scanning calorimetry. The simulations were used to compute the G(Ge-Ge) (RMC)(r), G(Ge-Se) (RMC)(r), and G(Se-Se) (RMC)(r) partial distribution functions and the S(Ge-Ge) (RMC)(K), S(Ge-Se) (RMC)(K), and S(Se-Se) (RMC)(K) partial structure factors. We calculated the coordination numbers and interatomic distances for the first and second neighbors and the bond-angle distribution functions Theta(ijl)(cos theta). The data obtained indicate that the structure of the alloy has important differences when compared to alloys prepared by other techniques. There are a high number of Se-Se pairs in the first shell, and some of the tetrahedral units formed seemed to be connected by Se-Se bridges.

Structural study of Cu(2-x)Se alloys produced by mechanical alloying.

The crystalline structures of the superionic high-temperature copper selenides Cu(2-x)Se (0 < x < 0.25) produced using mechanical alloying were investigated using X-ray diffraction (XRD). The measured XRD patterns showed the presence of peaks corresponding to the crystalline superionic high-temperature alpha-Cu(2)Se phase in the as-milled sample, and its structural data were determined by means of a Rietveld refinement procedure. After heat treatment in argon at 473 K for 90 h, this phase transforms to the superionic high-temperature alpha-Cu(1.8)Se phase, whose structural data were also determined by Rietveld refinement. In this phase, a very low occupation of the trigonal 32(f) sites ( approximately 3%) by Cu ions is found. In order to explain the evolution of the phases in the samples, two possible mechanisms are suggested: (i). the high mobility of Cu ions in superionic phases and (ii). the important diffusive processes in the interfacial component of samples produced by mechanical alloying.

Lipophilicity behaviour of the Zwitterionic antihistamine cetirizine in phosphatidylcholine liposomes/water systems.

PURPOSE: The partitioning of cetirizine in a phosphatidylcholine liposomes/water system was compared with that of hydroxyzine and acrivastine to gain insight into the mechanisms of interaction of its various electrical species with membranes. METHODS: The lipophilicity profiles of the compounds were obtained from equilibrium dialysis and potentiometry, and compared with changes in NMR relaxation rates. RESULTS: The neutral form of hydroxyzine interacted mainly via hydrophobic interactions with the bilayer lipid core of the membrane, whereas for the cationic form both hydrophobic and electrostatic interactions were involved. Zwitterionic and anionic cetirizine were less lipophilic than its cation, which behaved like the corresponding species of hydroxyzine. Zwitterionic cetirizine interacted more by weak electrostatic interactions with the polar headgroups of phospholipids than by hydrophobic interactions with the membrane interior. The lipophilicity of its anion reflected the balance of repulsive electrostatic interactions between the carboxylate and phosphate groups and the hydrophobic interactions with the lipid core. CONCLUSION: The study confirms that various mechanisms influence the interaction of solutes with liposomes. Combining experimental techniques and using suitable reference compounds proves useful.

Biological screening of Brazilian medicinal plants.

In this study, we screened sixty medicinal plant species from the Brazilian savanna ("cerrado") that could contain useful compounds for the control of tropical diseases. The plant selection was based on existing ethnobotanic information and interviews with local healers. Plant extracts were screened for: (a) molluscicidal activity against Biomphalaria glabrata, (b) toxicity to brine shrimp (Artemia salina L.), (c) antifungal activity in the bioautographic assay with Cladosporium sphaerospermum and (d) antibacterial activity in the agar diffusion assay against Staphylococcus aureus, Escherichia coli, Bacillus cereus and Pseudomonas aeruginosa. Forty-two species afforded extracts that showed some degree of activity in one or more of these bioassays.

Synthesis and pharmacological investigation of 9-methyl-1,2,3,4,6,7,12,12b-octahydro-7-oxo-indolo[2,3-a]quinolizine.

The title ketone, a supposed metabolite of 9-methyl-1,2,3,4,6,7,12,12b-octahydroindolo[2,3-a]quinoli zine (MIQ), was prepared and found different on chromatographic comparison from the isolated metabolite M4. However, the pharmacological screening of this compound evidenced, among others, some interesting properties as inhibition of arachidonic acid induced platelet aggregation and protection from both hypobaric and cyanide induced hypoxia in mice. These activities suggest a possible cerebroprotective action to be further investigated.

Monoamine oxidase inhibitor properties of some benzazoles: structure-activity relationships.

Benzazoles containing two or three nitrogen atoms were screened for their inhibitory activity toward monoamine oxidases MAO-A and MAO-B. In order to clarify the mechanism of interaction of these compounds with the enzyme, their electronic structure was calculated at the ab initio level and the influence of lipophilicity on activity was investigated. The mode of binding of benzazoles to MAO-B appears different from that of previously investigated heterocycles.

Synthesis and hybridization properties of the conjugates of oligonucleotides and stabilization agents--II.

New pyranone derivatives having tri- or pentamethylenamine linker functions were synthesized. These derivatives were covalently attached through the 5'-phosphoramide linkage to heptanucleotide pd(CCAAACA). Complementary complexes of the octanucleotide pd(TGTTTGGC) and above oligonucleotide conjugates were tested for their thermodynamic response. The Tm data and thermodynamic parameters for complex formation have demonstrated the ability of chromone (gamma-pyrone) and coumarin (alpha-pyrone) derivatives to stabilize strongly 7-mer/8-mer complementary complex, most likely through the stacking interaction of the pyran aromatic system with the neighboring nucleotide bases. The effect of chromone (or coumarin) derivatives on the stability of the oligonucleotide complexes (delta delta G at 37 degrees C ranged from -1.0 to -1.7 kcal/mol) was shown to be comparable to the effect of one nucleotide base pair and similar to the effect (delta delta G at 37 degrees C ranged from -1.5 to -2.0 kcal/mol) found for acridineoligonucleotide conjugates served in this study as a reference.

Screening of Asteraceae (Compositae) plant extracts for larvicidal activity against Aedes fluviatilis (Diptera:Culicidae).

Ethanol extracts of 83 plants species belonging to the Asteraceae (Compositae) family, collected in the State of Minas Gerais, Brazil, were tested for larvicidal activity against the mosquito Aedes fluviatilis--Diptera: Culicidae). The extract from Tagetes minuta was the most active with a LC90 of 1.5 mg/l and LC50 of 1.0 mg/l. This plant has been the object of several studies by other groups and its active components have already been identified as thiophene derivatives, a class of compounds present in many Asteraceae species. The extract of Eclipta paniculata was also significantly active, with a LC90 of 17.2 mg/l and LC50 of 3.3 mg/l and no previous studies on its larvicidal activity or chemical composition could be found in the literature. Extracts of Achryrocline satureoides, Gnaphalium spicatum, Senecio brasiliensis, Trixis vauthieri, Tagetes patula and Vernonia ammophila were less active, killing more than 50% of the larvae only at the higher dose tested (100 mg/l).

Synthesis and antirhinovirus activity of 3-(diethylamino)-5-phenylisoxazole derivatives.

Previous studies showed that some 2'-alkyloxyisoxazoles 2b-d obtained from 3-(diethylamino)-5-(2'hydroxy-4'-methoxyphenyl)isoxazole 2a were endowed with an interesting anti-group B rhinovirus activity (action on HRV-2 serotype). Other isoxazoles (WIN compounds) are well known to have anti-group A rhinovirus activity (action on HRV-14 serotype). To obtain an action similar to that of WIN compounds, starting from 2a, the 2'-acyl (3,4,5) and 2'alkyl (6,8) derivatives were synthesized. Also some Mannich bases (9,10) and bisisoxazoles (7,11,13,14) were studied. Though some of the tested compounds mainly exhibited anti-group B rhinovirus activity, their potency was less intense with respect to the above mentioned compounds 2b-d. The only N-methylpiperazinomethyl derivative 10 was slightly active against both tested serotypes.