The correlation between different techniques for the evaluation of oral malodour in children with and without orthodontic treatment

AIM

The aim of this work was to evaluate the correlation between different methods (organoleptic evaluation, gas chromatography, salivary ?-galactosidases activity) for the evaluation of halitosis in children. The secondary purpose was to investigate the influence of orthodontic treatment on halitosis.

MATERIALS AND METHODS

Study Design: Oral malodour was detected with different methods in 50 children in the Paediatric Dentistry Unit, University of Rome Tor Vergata, Rome, Italy. During the dental visit, level of oral hygiene, tongue coating scores and presence of an orthodontic device, fixed or mobile, were recorded. Two trained and calibrated operators performed the organoleptic evaluation; the Oral ChromaTM device was used for the volatile sulfur compounds (VSCs) quantification and salivary ?-galactosidases (S?-g) activity was evaluated through the spectrophotometric method.

STATISTICS

The Cohen's Kappa score was used to evaluate the level of agreement between the operators. The Pearson's correlation coefficient was used to evaluate the linear relationship between continuous variables (e.g. S?-g vs. VSCs values) and the Spearman's correlation coefficient was calculated for ordinal variables (e.g. organoleptic scores) vs. other parameters. The LSD test was used to compare the parameters analysed in the study.

RESULTS

A positive and significant correlation between the organoleptic evaluation, the S?-g, the levels of hydrogen sulfide (H2S) and methyl mercaptan (CH3SH) was found. The Spearman's correlation has shown that organoleptic scores were significantly correlated with S?-g (0.664, p<0.001) and the Oral ChromaTM measurements of H2S (0.538, p<0.001) and Ch3SH (0.316, p=0.026). The Pearson's correlation showed that S?-g was statistically significantly correlated with the Oral ChromaTM measurements of H2S (0.379 p=0.007) and Ch3SH (0.299, p=0.0035). Stratifying results for orthodontic treatment, it was possible to show that children under orthodontic treatment, both fixed or removable, were characterised by higher level of S?-g. The organoleptic evaluation and Oral ChromaTM measurements showed that children wearing fixed orthodontic were characterised by higher scores.

CONCLUSIONS

There was a significant correlation between the three different techniques for the evaluation of oral malodour in children. Like in the adult population, the increase of S?-g activity was associated with oral malodour. The presence of fixed orthodontic appliances was correlated to increased scores of all methods for the evaluation of halitosis.

Correlation between halitosis, oral health status and salivary ß-galactosidases and time spent in physical activities in children

AIM

The aim of this work was to evaluate the oral health status in children and to correlate it with time spent in physical activity per week.

MATERIALS AND METHODS

Fifty children (mean age 9±2 years) attending the first visit at the Paediatric Dental Unit of the University of Rome "Tor Vergata" have been included in the study. The parents of all patients were interviewed about the medical history of the children and specific data, in particular, the time spent in physical activity per week. A trained dentist examined the oral cavity of the patients and the following clinical parameters were recorded: number of deciduous and permanent teeth, caries (on deciduous and permanent teeth), presence of gingivitis (0=no; 1=yes), tongue coating score (from 0=none to 3= > 2/3 tongue dorsum surface covered)", oral infections (0=no; 1=yes), oral hygiene index (0=insufficient, 1=sufficient, 2=good), presence of at least one incongruous restoration (0=no, 1=yes), oral breathing (0=no; 1=yes), fissured tongue (0=no, 1=yes), presence of aftous ulcers, herpetic lesions or candidiasis (0=no, 1=yes), food stagnation (0=no; 1=yes). The level of salivary ?-galactosidases activity was measured spectrophotometrically. The subjects were classified into "Group 0": children who did not practice any sports beside physical education class; "Group 2": 2 hours per week; "Group 3": 3 hours; and "Group 4": 4 hours.

STATISTICS

Statistical analysis was performed using SPSS for Windows version 21 (IBM SPSS Inc., Chicago, IL, USA). The Pearson's correlation coefficient (P) was used to evaluate the linear relationship between continuous variables, and the Spearman's correlation coefficient (S) was calculated for ordinal variables. Analysis of variance (ANOVA) and the Fischer's Least Significant Difference (LSD) test were used to compare the parameters analysed in the study. Data were analysed using linear regression and descriptive statistics. The significance threshold was set at 0.05.

RESULTS

A more physically active lifestyle was significantly associated with a better oral hygiene and a reduced level of salivary ?-galactosidases, halitosis, gingivitis and tongue coating. Results of the organoleptic evaluation of halitosis performed by the parents and sport hours/week practiced have shown that Group 0 and 2 were characterised by statistically significant higher scores with respect to the other groups (Group 0 vs. Group 3, p=0.014; Group 2 vs. Group 3, p=0.030; Group 0 vs. Group 4, p=0.001; Group 2 vs. Group 4, p=0.002) (P= -0.458). The spectrophotometric quantification of salivary ?-galactosidases has shown that increasing the hours of sports, the enzyme activity significantly decreases (S= -0,330); similar levels were found with 0 and 2 hours of sports, but an important decrease has been recorded with both 3 (Group 0 vs. Group 3, p=0,011; Group 2 vs. Group 3, p=0,006) and 4 hours of sports practiced (Group 0 vs. Group 4, p=0,014; Group 2 vs. Group 4, p=0,008). The level of significance between children who did not practice sport and those who did for 3 and 4 hours a week was 0.005 (Group 0 vs. Group 3) and 0.0018 (Group 2 vs. Group 4) with respect to tongue coating scores (P= -0,511) and 0.012 for both groups with respect to gingivitis (Group 0 vs. Group 3; Group 0 vs. Group 4) (P=-0,427).

CONCLUSION

Children who practiced sport showed a better oral hygiene level and lower halitosis, with respect to those who did not.

Effect of pre-operatory low-level laser therapy on pain, swelling, and trismus associated with third-molar surgery

Background

The extraction of impacted third molars is commonly associated to pain, edema, trismus, limited jaw opening and movements. The aim of this retrospective study is to verify if pre-surgical low-level laser therapy (LLLT) associated with the extraction of impacted lower third molars could add benefits to the postoperative symptoms respect LLLT performed only after surgery.

Material and Methods

Data from 45 patients subjected to a surgical extraction of lower third molars were pooled and divided into three groups. Patients that received only routine management were inserted in the control group. Group 1, were patients that received LLLT immediately after surgery and at 24 hours. In group 2 were included patients treated with LLLT immediately before the extraction and immediately after the end of the procedure. Data were analyzed using linear regression and descriptive statistics.

Results

Both laser-treated groups were characterized by minor events of post-surgery complications of pain, edema, trismus. The use of NSAIDs in the first 24 hours was significantly inferior in Group 2.

Conclusions

Pre-surgical LLLT treatment seems to increase the analgesic effect of LLLT. However, trismus and edema were reduced in both laser treated groups, independently from the period of irradiation.

Key words:Laser, LLLT, pain, surgery, extraction, third molars, wisdom teeth.

Enzymatic Analysis of the Gingival Crevicular Fluid in Hypoxia of High Altitude (Everest)

The aim of this study is to determine the qualitative and quantitative changes of alkaline phosphatase (ALP) that occur in the Gingival Crevicular Fluid (GCF) in hypobaric-hypoxic conditions (high altitude). Hypoxia affects systemic adaptation responses in different organs. We examined 17 Caucasians subjects, of whom 13 were mountain climbers (1 female and 12 males), and 4 Tibetans (2 females and 2 males) following exposure to the hypoxia environment of high altitude. The study was conducted at different altitudes (0 m control, 1000 m, 5200 m above sea level) on Mount Everest. The protocol consisted of withdrawing crevicular fluid through the use of cones made of endodontic paper size 30 sectioned to 15 mm from the apex, inserted for 30 seconds in the gingival sulcus (about 2 mm). The analyzed sites were the mesial and distal, buccal and palatal of tooth 1.1 and 2.1. Blood exams were performed on the subjects using I-Stat, furnishing analysis in real time (about 2 mins). In agreement with other results reported in literature, in all the subjects we found an increase in the hematocrit and hemoglobin with a large range of values between them, and with significant differences, as analysed with the Fisher, Scheffe and Bonferroni/Dunn statistical methods. The enzymatic analysis of the GFC showed an increase of the levels of ALP at each altitude studied. With this preliminary study we show that hypoxic environment determines not only the well known cardiovascular systemic responses, but also crevicular fluid adaptation.

Gold nanoparticles as scaffolds for poor water soluble and difficult to vehiculate antiparkinson codrugs

We report the facile and non-covalent preparation of gold nanoparticles (AuNPs) stabilized by an antiparkinson codrug based on lipoic acid (LA). The obtained AuNPs appear stable in both dimethyl sulfoxide and fetal bovine serum and able to load an amount of codrug double the weight of gold. These NPs were demonstrated to be safe and biocompatible towards primary human blood cells and human neuroblastoma cells, one of the most widely used cellular models to study dopaminergic neural cells, therefore are ideal drug carriers for difficult to solubilize molecules. Very interestingly, the codrug-stabilized AuNPs were shown to reduce the accumulation of reactive oxygen species in SH-SY5Y cells treated with LD and did not change total oxidant status levels in cultured human blood cells, thus confirming the antioxidant role of LA although bound to AuNPs. The characterization of AuNPs in terms of loading and stability paves the way for their use in biomedical and pharmacological applications.

Effect of low energy light irradiation by light emitting diode on U937 cells

Photobiomodulation (PBM) can induce a set of different biological modulators either in vitro or in vivo. Experimental evidence has highlighted the role of light effects on the mechanisms related to inflammation, apoptosis and autophagy. The goal of this project was the evaluation of PBM on U937, an established cell line of histiocytic lymphoma origin. Several aspects of modulation of proinflammatory pathways were analyzed and autophagic and proapoptotic mechanisms related to low laser light exposure of cells were studied. As a source of low energy light emission, we used an NIR-LED device, characterized by an 880 nm-wavelength as light source. Flow cytometry analysis was performed on supernatants of controls and treated U937 cells to detect inflammatory cytokine levels. In order to evaluate NF-kB and caspase3 expressions, Western blot analysis was performed according to standard procedures. In this report, we show the effect of PBM on a monocyte/macrophage established tumor cell line (U-937). We demonstrate that LED exposure, in the presence or absence of lipopolysaccharide (LPS), activates cell degranulation, increased expression of Interleukin-8 (IL-8) and modulation of beta galactosidase activity. Evidence shows that the well-known pro-inflammatory nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) and the apoptotic marker (caspase3/cleaved-caspase3 ratio) are up-regulated in response to a proinflammatory biochemical pathway.

Bamifylline Similar to Theophylline and Caffeine is a Competitive Inhibitor of the Cyclic Nucleotide Phosphodiesterase V

Bamifylline was found to be a poor inhibitor of 3′,5′-cyclic GMP phosphodiesterase (PDE V) as other methylxanthines such as teophylline and caffeine. The IC50 was respectively 3.24, 2.91, 1.69 mM. Inhibition decreased at higher cGMP concentrations. Lineweaver-Burk plots were linear or nearly linear. Differences in the actions of these inhibitors presumably reflect differences in the molecular requirements for effective interaction at the catalytic site on phosphodiesterase.

Pulp-Dissolving Ability of Several Endodontic Irrigants: A Spectro-Photometry Evaluation

The aim of this study is to test the dissolving action of different concentrations of NaOCl (0.5%, 2.5% and 5%) and EDTA 17% on bovine pulp tissue, testing solutions at three different times (1, 5, 10 minutes). 100 mg. of dental pulp placed into a becher with 20 ml of solution was evaluated using a spectrophotometer. A solution of NaOCl 5% showed the highest solubility value. Samples treated with 2.5% NaOCl showed solubility values of 0.98 in one minute, 29.1 in five minutes and 57 in ten minutes. Groups treated with NaOCl 0.5% showed small dissolving modifications. 17% EDTA showed the lowest values of solubility. 5% NaOCl solution showed highest pulp dissolving ability, even a 2.5% solution showed high dissolving ability but in longer times.

Does cyclic guanosine monophosphate induce autophagy in thyroid malignant carcinoma through down-regulation of cyclic guanosine monophosphate phosphodiesterase?

The aim of this study was to evaluate whether or not the expression of cGMP- phosphodiesterases (cGMP-PDE) varies in different thyroid pathologies and to elucidate the relationship between the expression of cGMP-PDE, cGMP, and autophagy. Fifty-four thyroid biopsy samples, excised to perform the biopsy, were split into two parts and randomly assigned: one part was microscopically examined and histological classified, and the other was frozen and analysed in order to evaluate the cGMP-PDE activity. Intracellular cGMP was also measured. A strong expression of intracellular cGMP and cGMP-PDE activity was observed in carcinoma in respect to controls and benign pathologies. The level of cGMP-PDE in papillary carcinoma without lymph node involvement (N-) was approximately four-fold higher compared to those with lymph node invasion (N±). On the contrary, the cGMP was one and a half times higher in N± than N-. Our results are promising, although further epigenetical studies are needed to confirm this association. A correlation between the cGMP-degrading activity and the severity of thyroid pathology has been shown. The decrease of cGMP-PDE and the increase of cGMP in N± papillar carcinoma could be an autophagic stimulus, a defence mechanism of the body, against the cancer that is expanding and invading other tissues and organs.

A comprehensive approach to investigate the structural and surface properties of activated carbons and related Pd-based catalysts

Activated carbons and related Pd-based catalysts are investigated with a multi-techniques approach, which allows correlating structure and performance.

Alkaline phosphatase level in gingival crevicular fluid during treatment with Quad-Helix

The aim of this work is to assess the level of the human alkaline phosphatase enzyme (ALP) during palatal expansion with Quad-Helix (QH) appliance. A total of twenty-two orthodontic patients characterized by contraction of the upper jaw, that needed application of a QH in order to treat their condition, were included in this study. Gingival crevicular fluid (GCF) was collected at four different times: before cementation (T0), after two weeks (T1), after four weeks (T2) and after one year (T3) from application of QH. In each patient maxillary first molars, right (UM-right) and left (UM-left), which were connected with bands to QH, were used for testing; first lower molars were used as Controls (LM-right, LM-left). Data show that ALP level in tension sites was proportional to the average increase of the inter-molar distance; on the contrary, the enzymatic level in compression sites was characterized by an inverse trend. The only exception to this phenomenon was recorded after one year (T3), when the increase of ALP level in both sites of tension and compression was ascribed to a mild inflammation due to bacterial plaque accumulation. The level of ALP in control sites was constant for the whole period of observation. The described ALP fluctuations in accordance with the inter-molar distance increment, shows that the main action of QH on bone remodelling was exerted during the fourth week (T2); for this reason, the monitoring of this enzyme could be used as a marker of effective function of the QH appliance.

Influence of alumina particles in the production of biomimetic composites

AIM

The aim of the work was to evaluate the influence of the filler size and shape in the final architecture of biomimetic composite produced through the freeze casting technique.

METHODS

Different samples of ceramic infiltrated with resin, composed by a different ratio between RonaFlair White Sapphire aluminium oxide powder - EMD Chemicals/Rona Gibbstown, USA (platelet-like morphology and average particle size <16 µm) and Almatis alumina filler ‑ CT3000SG, Almatis, USA (average particle size of 0.8 µm) have been produced. The samples have been then characterized through thermal analysis and calorimetry (Model TG/DT A 6300, Seiko Instruments USA Inc. Torrance, CA, USA), scanning electron microscopy (Phenom-World BV, Eindhoven, The Netherlands), and optical microscope (Nikon Eclipse E600 microscope). Moreover the percentage of shrinkage after the ceramic sintering have been measured through a digital calibre (Mitutoyo USA, Aurora, IL, USA). Four different groups have been considered: Group 1 (10R): 10% RonaFlair- 90% Almitas; Group 2 (20R): 20% RonaFlair- 80% Almitas; Group 3 (40R): 40% RonaFlair- 60% Almitas; Group 4 (60R): 60% RonaFlair- 40% Almitas.

RESULTS

Optical microscope and SEM observations have confirmed that all samples were characterized by a biomimetic hierarchic structure. For what concerning the average thickness of lamellae measured at 4 and 8 mm from the cooling plate, samples 10R were characterized by higher thickness at both levels. The measured parameter indeed decreases with the increment of the percentage of RonaFlair in the slurry composition. On the contrary the distance between lamellae (wavelength), was characterized by an opposite trend. The measurement of the diameters of the samples after the sintering process through a digital calibre has shown that 10R and 20R samples were characterized by a constant shrinkage in all the samples. On the contrary, groups 40R and 60R were distorted and were characterized by a higher diameter at the bottom respect the upper portion of the samples. Indeed these samples were characterized in the bottom by a greater amount of particles, both Almatis than RonaFlair ones. We have supposed that gravity force, during the freeze casting process, tended to push down in the lower layers all heaviest particles and then the lightest ones have occupied the spaces they have left. Consequently in upper layers there were only few particles so during the sintering process were characterized by the higher shrinkage. This phenomenon was limited in samples 10R and 20R because the percentage of greatest particle was so much inferior that their position was not influential.

CONCLUSION

The present study has shown that samples composed by a higher percentage of RonaFlair, were characterized by a higher distortion after sintherization; the cause of this phenomenon could be the different sedimentation process that characterizes particles of different weight and size.

Prostaglandin E2 to diagnose between reversible and irreversible pulpitis

The aim of this work is to verify a correlation between the grade of inflammation and the concentration of PGE2 in human dental pulp. A total of 25 human dental pulps were examined by histological analysis and radioimmunologic dosage of PGE2. The pulps used in this experiment were from healthy and symptomatic teeth; the first ones were collected from teeth destined to be extracted for orthodontic reasons. An increase was observed of PGE2 in reversible pulpitis compared with healthy pulps and with the irreversible pulpitis and the clear decrease of these when NSAIDs are taken. This study demonstrates that PGE2 level is correlated to histological analysis thus allowing to distinguish symptomatic teeth in reversible and irreversible pulpitis.

Micromorphometrical and histological analyses using two different oscillating osteotomy techniques compared with conventional rotary osteotomy

The recently introduced ultrasonic osteotome procedure is an alternative to conventional rotatory burs. The aim of this study was to establish the differences between two ultrasonic osteotomes and conventional rotatory burs, in order to perform micromorphological and histological analyses of osteotomized bone surfaces. Bony samples were taken from adult bovine ribs including both the cortical and marrow bone. Soft tissues have been removed and the bone pieces were divided into four groups, to test four devices: a conventional osteotomy round bur, a Lindeman bur and piezoelectric osteotomes ES007 and the T-Black. Each device performed cuts that were examined via scanning electron microscope (SEM) and light microscopy (LM) to check respectively cut precision and bone architecture all along the defect borders. SEM analysis of specimens showed that burs created defects of greater width and with irregular edges while those produced by ultrasonic osteotomes were narrow and had mostly smooth cutting surfaces. The edges of incisions made by drills were full of bone fragments while less bone chips were observed on piezoincision’s ones. Dimensions of fragments were wider if cuts were made by burs too. LM analysis of samples showed focally, delicate bony trabecules crushed and pressed into the bone marrow in cutting made by burs. Samples cut by ultrasonic devices showed small or no smear layer and only partial or no crushed trabecules. Osteocytes seemed to be intact all along the cutting surface in all samples observed. In the present study, according to literature, ultrasonic surgery validity is confirmed. As a matter of fact, the greater the number of bone chips products, the greater the magnitude of the inflammatory process induced, as well as the possibility of a greater bone loss and delay in wound healing near the osteotomized area.

Thermal analysis of laser-softened gutta-percha

The aim of this work is to examine the behaviour of laser treated gutta-percha (a–b) after heating, to test the validity of a new obturation technique. Samples of laser- and no laser- treated gutta-percha have been examined by the thermal/thermogravimetric analysis and compared. All samples have been submitted to four runs of heating from the temperature of 25–130 C, followed by spontaneous cooling. It was found that some samples have shown the typical behaviour of the alpha-gutta-percha; others have shown characteristics similar to the conventional beta-gutta-percha. The laser treated gutta-percha has shown a significant mass loss after the first run of heating, while the mass tends to stabilize after the third run. It has been demonstrated that the 980 nm diode laser used with cited parameters does not alters thermal behaviour of gutta-percha cones.

Bevacizumab-Related Osteneocrosis of the Jaw

We describe a case of jaw bone necrosis after a lung adenocarcinoma bone metastasis, treated the first time in 2004 by means of pneumonectomy and lymph node ablation. One week after a dental extraction, the patient experienced pain in the mandibular region, in conjunction with alveolar bone exposure. Treatment with amoxicillin and clavulanate every 12 hours for 15 days and 0.2% chlorhexidine rinses was administered and there was a remission of infective complications, but not the closure of the exposed alveolar bone. Only at this time did the patient refer that he was treated with bevacizumab therapy immediately after the extraction. A preventive dental assessment of patients scheduled for bevacizumab therapy should be useful as for the zoledronic acid therapy. Dental surgery procedures for patients during bevacizumab therapy should be carefully evaluated and considered as the last choice, to reduce all possible risks and prevent complications.

Microbiological and Biochemical Effectiveness of an Antiseptic Gel on the Bacterial Contamination of the Inner Space of Dental Implants: A 3-Month Human Longitudinal Study

Microbial penetration inside the implant's internal cavity produces a bacterial reservoir that is associated with an area of inflamed connective tissue facing the fixture-abutment junction. The aim of this clinical trial is to evaluate the effectiveness of a 1% chlorhexidine gel on the internal bacterial contamination of implants with screw-retained abutments and on the level of AST secreted in peri-implant crevicular fluid. Twenty-five patients (aged 29 to 58 years) each received one implant. Three months after the end of the restorative treatment, and immediately after a clinical and radiographic examination and the abutment removal, microbiological samples were obtained from the internal part of each fixture and biochemical samples were collected by peri-implant sulci. The patients were then divided into two groups: the control (CG; n=10) and test (TG; n=15) groups. The CG had the abutment screwed into place and the crown cemented without any further intervention. In contrast, before the abutment placement and screw tightening, the TG had the internal part of the fixture filled with a 1% chlorhexidine gel. Three months later, the same clinical, microbiological and biochemical procedures were repeated in both groups. Total bacterial count, specific pathogens and AST activity were detected. The clinical parameters remained stable throughout the study. From baseline to the 3-month examination, the total bacterial counts underwent a significant reduction only in the TG. In contrast, the AST activity showed a significant increase in the CG. The administration of a 1% chlorhexidine gel appears to be an effective method for the reduction of bacterial colonization of the implant cavity and for safeguarding the health status of peri-implant tissue over a 3-month administration period.

Demineralizing action of EGTA in endodontics

The demineralization of dentin obtained by treatment with a chelating agent ethylene diamminotetracetic acid (EDTA) or ethylene glycol-bis(beta-aminoethyl ether)-N-tetraacetic acid (EGTA), is a dynamic process involving chelation and solubilization. The actions of the EDTA and EGTA on dentin are influenced by the pH. Increasing mM concentrations of EDTA or EGTA the equivalent pH decreases in a similar slope to 80 mM chelator concentration. Increasing the chelator concentration different data were obtained: with EGTA the pH decreases slightly while with EDTA goes back up to the initial values. After 80 mM, EDTA reduces the activity on the dentin, and EGTA continues to work at higher concentrations. We demonstrated that EGTA solubilized more of 60 percent of dentin while EDTA gives about 20% at the maximal of the solubility.

Role of the friction free distalize appliance (2FDA)PAT in the molar distalization: photoelastic analysis and alkaline-phosphatase (ALP) activity on first molar and bicuspid

Maxillary molar distalization is an increasingly popular option for the resolution of Class II malocclusions. This study describes the effects of one particular molar distalizing appliance, the Friction Free Distalize Appliance (2FDA), in a sample of 20 consecutively treated and growing patients to verify the osteoblastic activity in the compression and traction sites of both the molars and the bicuspids when used as the anchorage teeth. The 2FDA appliances were constructed utilizing a Nickel Titanium open coil spring of 200 gr force in order to distalize the maxillary first molar. The reaction force was controlled utilizing the principle of low/free friction. The results show that the resin around the root of the bicuspid did not discolour at all, which indicates an absence of a force load. On the other hand, on the molar, the resin around the root of the molar became discoloured due to the fact that an orthodontic force was involved with the tooth. To better understand whether the quantity of force that reached the tooth was able to produce osteoblastic recruitment in the sites of tension of the molar and the bicuspid, we quantified an enzyme, the alkaline phosphatase (ALP), present. This measurement allowed us to verify a regular increase of the ALP on the site of molar traction. We also elaborated a mathematical model to evaluate the quantity of force of reaction that produces the device on the bicuspid. Such force results as being 8.34 grams which equals half the pressure of the capillaries of the parodontal ligament (18 grams). The 2FDA appliance compares favourably with other intra-oral distalization devices for the resolution of patients with Class II malocclusions, and is the only distalizing appliance that does not determine osteoclastic/osteoblastic recruitment on the anchorage tooth.

Effect of a subgingival chlorhexidine chip on the clinical parameters and the levels of alkaline phosphatase activity in gingival crevicular fluid during the non-surgical treatment of periodontitis

The main therapeutic approaches for inflammatory periodontal diseases include the mechanical treatment of root surfaces. Multi-center clinical trials have demonstrated that the adjunctive use of a chlorhexidine (CHX) chip is effective in improving clinical results compared to scaling and root planing (SRP) alone. However, some recent studies failed to confirm these clinical results, nor have any data been reported regarding the capability of the CHX chip in affecting the activity of alkaline phosphatase (ALP) in the gingival crevicular fluid (GCF). This enzyme has been related to a condition of destructive activity of periodontitis. The aim of this study is to provide further data on the clinical and biochemical effects of CHX chips when used as an adjunct to SRP. Eighty-two systemically healthy patients, aged 31-63, with moderate and advanced periodontitis were recruited from the departments of Periodontology of the University of Chieti. In each patient 2 experimental sites, located in two symmetric quadrants, were chosen with a probing depth of > or = 5 mm and bleeding on probing. The 2 sites were selected randomly at the split-mouth level; control sites received SRP alone, and test sites SRP plus 1 CHX chip. Clinical indices, including probing depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP), and the ALP activity in GCF were evaluated at baseline and after 6 months. Alkaline phosphatase activity was assayed spectrophotometrically. The PPD and CAL were significantly lower at 6 months as compared to the baseline scores in both treatments (p less than 0.01). The PPD reduction was 2.7 mm in the CHX+SRP group and 1.9 mm in the SRP alone group. The CHX+SRP group showed a significantly greater gain of clinical attachment (mean: 1.4 mm) in comparison with the SRP group (mean: 0.9; p less than 0.05). No differences were observed in the decrease of the percent of BOP-positive sites between the experimental groups. Conversely, the CHX+SRP group underwent a significantly greater decrease (p less than 0.01) of the GCF-ALP activity 6 months after treatment in comparison with the SRP alone group. The adjunctive use of the CHX chip resulted in a significant improvement of pocket reduction and clinical attachment gain as compared with SRP alone. These results were concomitant with a significantly greater reduction of the GCF-ALP activity levels.

cAMP phosphodiesterase activity evaluation in human carcinoma of salivary glands

The aim of this study was to evaluate differences of cAMP-PDE activity in human salivary glands, between a control group and some different benign tumours groups and, where present, with 2 malignant tumors groups. The value of the enzymatic activity in the groups analysed was 50% lower than control samples. The differences between the control group (82 +/- 7.9 nmols/mg of protein) and the 3 pathologic groups (Benign A: 44 +/- 6.2; Malignant A: 40 +/- 16; Benign B: 40 +/- 14.2; Malign A: 9.1; Benign C: 22 nmols/mg of protein) are statistically significant.

Evaluation of non-specific tissue alkaline phosphatase on bone samples from traditional and piezoelectric osteotomy

The aim of this study is to test the response of bone during cutting actions in dental procedures by sampling alkaline phosphatase (ALP) as a biological reference marker. ALP is found abundantly in bone tissue. In the first series of experiments a temporal-minimum quantity of ALP enzyme response was recorded, the observed period was 40 minutes. The ALP samples treated with piezoelectric surgery showed a rapid increase, with peak at 30 min, and then declined rapidly within the next 10 minutes. A second experiment was performed to evaluate 4 cutting instruments: drill bits high speed turbine (T1); drill bits contra-angle (T2) Piezoelectric insertions (T3), and manual instruments (controls). This second experiment was to evaluate the ALP activity at 30 min. The T1 samples produced the highest results (3,66499 +- 0,51394); control groups had a lower response (0,72793 +- 0,22353), while the T2 group produced statistically significant higher results (2,77793 +- 0,40553) than T3 (1,16608 +- 0,32676). The different values obtained for ALP in these two experiments for a short period of time (30 min) cannot be interpreted as a response of bone tissue regeneration subjected to surgical trauma. The MINIMUM trauma caused by the surgical piezoelectric instruments, in respect to conventional surgical instruments is clearly evident from the phosphatase inflammatory activity.

Direct IR observation of vibrational properties of carbonyl species formed on Pd nano-particles supported on amorphous carbon: comparison with Pd/SiO2–Al2O3

By diluting optically opaque carbon-supported Pd particles in silica Aerosil we succeeded in observing the IR bands of adsorbed carbonyls and extracting information on the particle dispersion. Comparison with literature single crystal data and with silica-alumina supported Pd allowed us to make an assignment in terms of linear and 2-fold bridged carbonyls formed on Pd(111) and Pd(100) faces. Two Pd/C samples have been investigated. The relative intensities of the two carbonyl families observed on the two samples are consistent with the Pd dispersion independently measured with CO chemisorption, TEM and EXAFS analysis.

FTIR Investigation of the H2, N2, and C2H4 Molecular Complexes Formed on the Cr(II) Sites in the Phillips Catalyst: a Preliminary Step in the understanding of a Complex System

This work reports the first complete FTIR characterization of H2, N2 and C2H4 molecular complexes formed on the Cr(II) sites in the Phillips catalyst. The use of a silica aerogel as support for Cr(II) sites, substituting the conventional aerosil material, allowed us to obtain a remarkable increase in the signal-to-noise ratio of the IR spectra of adsorbed species. The improvement is directly related to an increase of the surface area of the support (approximately 700 m2 g(-1)) and to an almost complete absence of scattering [Groppo et al., Chem. Mater. 2005, 17, 2019-2027]. The use of this support and the adoption of suitable experimental conditions results, for the first time, in the clear observation of H2 and N2 adducts formed on two different types of Cr(II) sites, thus yielding important information on the coordinative state of the Cr(II) ions, which well agrees with the evidences provided in the past by other probe molecules. Furthermore, we report the first complete characterization of the C2H4 pi-complexes formed on Cr(II) sites. These results are particularly important in the view of the understanding of the polymerization mechanism, since the C2H4 coordination and the formation of pi-bonded complexes are the first steps of the reaction.

Changes of Plasma Membrane Properties in a Human Pre-T Cell Line Undergoing Apoptosis

A variety of cellular functions are modulated by the physical properties of the cell membrane, and the modification of intracellular transfer, resulting from loss of membrane integrity, may contribute toward setting the cell onto the pathway of apoptosis. Apoptosis in lymphoid cells can be induced in different ways and biochemical modifications occur at an early phase of cell death, while the morphological features of apoptosis are evident later. We previously reported that DMSO is an efficient apoptosis-inducing factor in the human RPMI-8402 pre-T cell line. The aim of the present study was to verify the effect of DMSO on the plasma membrane fluidity, the intracellular calcium concentration and the phosphodiesterase activity in DMSO-induced apoptosis. Our results show a modification of membrane fluidity associated with an increase of intracellular Ca(2+) concentration. Moreover, we demonstrate that these modifications are related to a decrease in the phosphodiesterase (PDE) activity. The correlation between the proceedings of added DMSO and the induction of apoptosis will provide significant information regarding the first part of the apoptotic process.

Cyclase and phosphodiesterase activity on pre-T lymphoid human cells, treated with dimethyl sulfoxide (DMSO)

Our aim is to estimate the role of the DMSO on pre-T lymphoid human cells, we have searched the cyclase and phosphodiesterase activity. We have studied the GTPspecific cyclase (G-Case) and have observed an analogous course to that one of the cAMP-PDE, where, in both cases, the differences ratio is approximately 5. For the cyclase activity values it has been found that cAMP neo formed is undeterminable in these cells, for the controls and the treated samples.

Electrosynthesis and analytical characterization of PMMA coatings on titanium substrates as barriers against ion release

The performance of polyacrylic coatings as barrier films against corrosion of titanium-based orthopaedic implants was investigated. In particular, poly(methyl methacrylate) (PMMA) was electrosynthesized on titanium substrates by electro-reductive processes from aqueous monomer solutions. The obtained PMMA coatings were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The effect of an annealing treatment on the morphology of coatings with respect to uniformity and porosity of films was assessed by scanning electron microscopy (SEM). An inductively coupled plasma-mass spectrometry (ICP-MS) technique was used for ion concentration measurements in ion release tests performed on TiAlV sheets modified with PMMA coatings (annealed and unannealed). Results indicated that the annealing process produces coatings with considerable anticorrosion performances.

cAMP phosphodiesterase activity in diabetic rats eyes in normoxic, hypoxic and hyperoxic conditions

Phosphodiesterase activity was tested on homogenized eyes of pre-diabetic rats kept in normoxic, hypoxic and hyperoxic conditions, with the aim of correlating any difference in PDE activity with variations in atmospheric oxygen contents. The activity of the cAMP phosphodiesterase (cAMP-PDE) was tested. Phosphodiesterases seem to be particularly susceptible to variations in oxygen tension, suggesting an important role of cyclic nucleotides in adaptive processes of the cell. cAMP-PDE activity increases slightly in normoxic, hypoxic and hyperoxic conditions in pre-diabetic rats. The second messenger, cAMP, plays important roles in mediating the biological effects of a wide variety of first messengers. The intracellular levels of cyclic nucleotides depend upon rates of synthesis and degradation, of cyclases and phosphodiesterase (PDEs), respectively. Therefore, PDEs seem to play an important role in a wide variety of physiological processes.

Cyclic Amp phosphodiesterase activity in normal and inflamed human dental pulp

Cyclic AMP phosphodiesterase (cAMP PDE) seems to be important in pulp tissues. High levels of cAMP PDE have been demonstrated to be in dental pulp cells. In the present study cAMP PDE activity was analyzed in normal healthy human dental pulps, in reversible pulpitis and in irreversible pulpitis. Enzymatic cAMP PDE control values for normal healthy pulps were 12.14 +/- 3.74 nmols/mg of proteins. In reversible pulpitis the cAMP PDE activity increased almost 2.5 times. In irreversible pulpitis specimens the values increased 4.5 times compared with normal healthy pulps activity. The differences between the groups (control vs. reversible pulpitis and vs. irreversible pulpitis) were statistically significant. These results could point to a role of cAMP PDE in the initial pulp response after injury.

cGMP phosphodiesterase activity in diabetic rats eyes in normoxic, hypoxic and hyperoxic conditions

Phosphodiesterase activity was tested on homogenized eyes of pre-diabetic rats kept in normoxic, hypoxic and hyperoxic conditions, with the aim of correlating any difference in PDE activity with variations in atmospheric oxygen contents. The activity of the cGMP phosphodiesterase (cGMP-PDE) was tested. Phosphodiesterases seem to be particularly susceptible to variations in oxygen tension, suggesting an important role of cyclic nucleotides in cellular adaptive processes. cGMP-PDE activity increases lightly in normoxic, hypoxic and hyperoxic conditions in pre-diabetic rats. The second messenger, cGMP, plays important roles in mediating the biological effects of a wide variety of first messengers. In particular, cGMP in the eye is an important mediator for the mechanism of sight. The intracellular levels of cyclic nucleotides depend upon the rates of synthesis and degradation, actuated, respectively, by cyclases and phosphodiesterases (PDEs). Therefore, PDEs seem to play an important role in a wide variety of physiological processes.

Cyclic GMP phosphodiesterase activity role in normal and inflamed human dental pulp

Cyclic GMP phosphodiesterase (cGMP PDE) plays an important role in pulp tissues. High levels of cGMP PDE are found in dental pulp cells. In the present study cGMP PDE activity was analyzed in normal healthy human dental pulps, in reversible pulpitis and in irreversible pulpitis. Enzymatic cGMP PDE control values for normal healthy pulps were 4.74+/-0.32 nmol/mg of proteins. In reversible pulpitis the cGMP PDE activity increased almost 3 times. In irreversible pulpitis specimens the values increased 4.5 times compared with the normal healthy pulps activity. The differences between the groups (control vs. reversible pulpitis and vs. irreversible pulpitis) were statistically significant. These results point to a role of cGMP PDE in the initial pulp response after injury.

cGMP phosphodiesterase activity evaluation in human carcinoma of salivary glands

The aim of this study was to evaluate differences of cGMP-PDE activity in salivary glands, between a control group and different benign tumour groups and, where present, with malign tumour groups. Endogen cGMP was evaluated too. The enzymatic reaction used the method of Spoto et al., with minor variations. The samples were organized in six groups: A (Adenolymphoma and Warthins tumour); B (Pleomorphic Adenoma); C (Basaloid Adenoma); D (Myoepitelioma). The control group was represented by healthy patients. In A and B groups, we have analyzed malign pathologies (Adenocarcinoma and Parotid Lymphoma) The benign tumours have more activity than controls, especially in Myoepitelioma (D) but with a decrement in the C group, which presents lower values of cGMP than the other three groups, where the concentration is similar. Between A and B groups, the activity values of malign tumours are similar, higher than controls and than the other benign pathologies, but not higher than in myoepitelioma. The cyclic concentration is similar for malign pathologies, with concentrations lower than controls, similar to Basaloid Adenoma (C).

Population dynamics in ageing Helicobacter pylori

The aim of this work was to characterize population changes occurring in aged broth cultures of Helicobacter pylori. Experiments were performed using clinical strains cultured immediately after isolation and after multiple subcultures in solid medium. Morphological changes in the ageing bacteria during a 7-day broth culture were analysed by optical and electron microscopy. The expression of the virulence factor, CagA, together with the presence of the cell cycle regulator, cGMP, were also assessed. The transition from bacillary to coccoid forms was the main morphological change observed in freshly isolated bacteria, together with the increase in cGMP from 1 to 2.25 nmoles/mg of proteins within the first 7 days of broth culture. A similar trend of morphological and physiological changes was observed in cells after multiple subcultures in solid medium with a major presence of large cell clusters. The cagA gene product was always expressed in all experimental conditions evaluated. These data show a significant morphological and physiological diversity in fresh, ageing and aged cultures of H. pylori.