Cardiovascular rehabilitation after valvular heart surgery: predictive factors of major complications

Background

The population of patients affected by valvular heart disease is growing and for many of them valvular surgery is still considered the gold standard treatment. Cardiovascular Rehabilitation (CR) following intervention is fundamental for the post-surgical functional recovery and for the monitoring and management of complications that may occur after surgery.

Aim of the study

We aimed at identifying predictors of major complications in patients who underwent valvular surgery and subsequently were involved in an in-patient CR program. Major complications were defined as those requiring an in-patient management: severe anemia needing transfusions, infection of the sternal surgical wound requiring an antibiotic treatment, a positive hemoculture in the presence of systemic signs of infection and pericardial effusion requiring surgical drainage.

Methods and statistical analysis

1600 patients who have been hospitalized in our CR Unit after valvular surgery were enrolled (median age 64 years; 60% males). We examined the demographic data, the cardiovascular risk factors, the main comorbidities, the type of heart surgery (type of valvular surgery and the presence of concomitant other cardiac intervention), the complications developed in Cardiac Surgery Unit and in the CR Unit, the in-hospital length of stay, the 6 minutes-walking tests and principal blood tests.

Results

At multivariate analysis we found that chronic renal dysfunction [OR 1,902 (CI 1,103–3,280), p=0,021], complex cardiac intervention [OR 1,554 (CI 1,030–2,344), p=0,036], sternal re-synthesis [OR 4,671 (CI 1,659–13,152), p=0,004], early post-surgical transfusions [OR 1,670 (CI 1,083–2,573), p=0,020] are independent risk factors for major complications, while a higher hemoglobin value at CR admission [OR 0,677 (CI 0,566–0,810), p<0,001] resulted an independent protective factor.

Conclusions

We identified predictors of major complications during CR after valvular surgery. These factors may help in defining the patients at major risk tailoring the patient management, adopting an individualized clinical and instrumental monitoring. A tailored CR period gives the possibility to optimize the use of hospital economic resources and to achieve a better final outcome.

Funding Acknowledgement

Type of funding source: None

Subacute post-operative atrial fibrillation after valvular surgery in patients undergoing cardiac rehabilitation: predictive factors

Background

Postoperative atrial fibrillation (POAF) is the most frequent arrhythmic complication following cardiac surgery (occurring in up to one third of patients). It may develop between the second and fourth postoperative days (acute POAF) as well as later, within 30 days after surgery (subacute). Episodes of atrial fibrillation in the subacute phase (sPOAF) are associated with an increase in morbidity, length of hospital stay and several complications both in the mid- and long- term. Therefore, POAF is not just an acute event but it may impact on long term clinical outcomes.

Aim of the study

The aim of this study was to identify the clinical predictors of postoperative atrial fibrillation in the subacute phase (sPOAF) in patients performing Cardiovascular Rehabilitation (CR) after cardiac surgery.

Materials and methods

A retrospective study was conducted on 737 post-surgical valvular patients (median age 62 years; 55,4% male) hospitalised in our Unit for in-patient CR program. During all the hospital stay patients received continuous monitoring with 12-lead ECG telemetry. We evaluated the predictive value of anamnestic data, the type of cardiac surgery intervention, the clinical course in the Cardiac Surgery Unit and in the CR Unit, the 6 minutes-walking tests (6MWT) parameters and main blood tests on sPOAF onset.

Results

SPOAF was documented in 170 patients (23,1%). Those who developed sPOAF were older [median 66 (56–74) years vs median 61 (50–70) years; p<0,001), had a history of atrial fibrillation prior to surgery (29,4% vs 16,2%; p<0,001), had a worse functional result at the 6MWT at the admission in CR Unit [median 250 (180–320) vs median 275 (210–370); p=0,015], had higher values of neutrophil-lymphocite ratio at baseline [median 2,33 (1,84–3,27) vs median 2,17 (1,64 - 2,87); p=0,027] when compared to those who did not develop POAF. At the multivariable logistic regression analysis, the occurrence of POAF in the acute phase (OR 2,916; 95% CI 2,011–4,228; p<0,001), advanced age (OR 1,027; 95% CI 1,01–1,044; p=0,002), previous history of atrial fibrillation (OR 1,652; 95% CI 1,068–2,555; p=0,024), higher values of NLR at baseline (OR 1,144; 95% CI 1,028–1,272; p=0,013) and mitral valve surgery (OR 1,632, 95% CI 1,075–2,480; p=0,022) were found to be independent predictors of sPOAF after cardiac surgery.

Conclusions

Atrial fibrillation is a common complication after cardiac surgery with great clinical relevance. Advanced age, previous history of AF, higher values of NLR at baseline, mitral valve surgery and the occurrence of POAF in the acute phase were shown to be predictors of sPOAF in a cardiac surgery population during the rehabilitation period.

Funding Acknowledgement

Type of funding source: None

Topographic lymph node staging system shows prognostic superiority compared to the 8th edition of AJCC TNM in gastric cancer. A western monocentric experience

INTRODUCTION

The current Tumor Node Metastasis staging system (TNM) for gastric cancer classifies the extent of lymph node metastasis based upon the number of lymph nodes involved. Choi et al. have recently proposed a new anatomical classification based upon the regionality of the involved nodes. This new classification seems to have a better predictive prognostic value than the traditional one. We investigated the prognostic role of the new anatomical based classification, reviewing our institutional gastric cancer database.

METHODS

We performed a retrospective chart review of 329 patients who underwent gastrectomy at our Institution from 2003 to 2017. We excluded from data analysis any patient with distant metastases at the time of first diagnosis and or surgery, pathology other than adenocarcinoma, lymphadenectomy less than D2, impossibility to identify location of lymph nodes (LNs) on pathological report and neoadjuvant chemotherapy. The extent of D2 lymphadenectomy was defined according to Japanese Gastric Cancer Association criteria. LN metastasis were reclassified into three topographic groups (lesser, greater curvature, and extraperigastric nodes) and staged according to Choi. The new N stage was combined with the current pT according to the 8th edition of TNM and a new hybrid TNM stage was established. All patients were followed up until June 2019. The prognostic performance of the new stage and of the current anatomical numeric based system (TNM) was analyzed and assessed by the C-index, AIC and likelihood ratio χ² value.

RESULTS

In predicting both Overall Survival (OS) and Disease free Survival (DFS) the new N stage and the new TNM staging system had the highest C-index and likelihood ratio χ2 value and the lowest Akaike Information Criterion (AIC), showing a better accuracy and displaying a better prognostic performance.

CONCLUSIONS

Our study is the first from the Western world to compare the new hybrid classification, based on the anatomical location of metastatic nodes, to the 8th of American Joint Committee on Cancer (AJCC) TNM staging system. Our findings on a small, monocentric sample suggest that hybrid topographic lymph node staging system is more accurate than TNM.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Revisiting the role of sucrose in PLGA-PEG nanocarrier for potential intranasal delivery

The efficient design of nanocarriers is a major challenge and must be correlated with the route of administration. Intranasal route is studied for local, systemic or cerebral treatments. In order to develop nanocarriers with suitable properties for intranasal delivery, to achieve brain and to market the product, it is extremely important the simplification of the formulation in terms of raw materials. Surfactants and cryoprotectants are often added to improve structuration and/or storage of polymeric nanoparticles. PLGA-PEG nanocarriers were prepared by nanoprecipitation method evaluating the critical role of sucrose as surfactant-like and cryoprotectant, with the aim to obtain a simpler formulation compared to those proposed in other papers. Photon correlation spectroscopy and Turbiscan analysis show that sucrose is a useful excipient during the preparation process and it effectively cryoprotects nanoparticles. Among the investigated nanocarriers with different degree of PEG, PEGylated PLGA (5%) confers weak interaction between nanoparticles and mucin as demonstrated by thermal analysis and mucin particle method. Furthermore, in vitro biological studies on HT29, as epithelium cell line, does not show cytotoxicity effect for this nanocarrier at all texted concentrations. The selected nanosystem was also studied to load docetaxel, as model drug, and characterized by a technological point of view.

Quadrupole transition strength in the (74)Ni nucleus and core polarization effects in the neutron-rich Ni isotopes

The reduced transition probability B(E2;0(+)→2(+)) has been measured for the neutron-rich nucleus (74)Ni in an intermediate energy Coulomb excitation experiment performed at the National Superconducting Cyclotron Laboratory at Michigan State University. The obtained B(E2;0(+)→2(+))=642(-226)(+216)  e(2) fm(4) value defines a trend which is unexpectedly small if referred to (70)Ni and to a previous indirect determination of the transition strength in (74)Ni. This indicates a reduced polarization of the Z=28 core by the valence neutrons. Calculations in the pfgd model space reproduce well the experimental result indicating that the B(E2) strength predominantly corresponds to neutron excitations. The ratio of the neutron and proton multipole matrix elements supports such an interpretation.

Nonsudden limits of heavy-ion induced knockout reactions

We report on the single neutron and proton removal reactions from unstable nuclei with large asymmetry ΔS = S(n)-S(p) at incident energies below 80 MeV/nucleon. Strong nonsudden effects are observed in the case of deeply-bound-nucleon removal. The corresponding parallel momentum distributions exhibit an abrupt cutoff at high momentum that corresponds to an energy threshold occurring when the incident energy per particle is of comparable magnitude to the nucleon separation energy. A large low-momentum tail is related to both dissipative processes and the dynamics of the nucleon removal process. New limits for the applicability of the sudden and eikonal approximations in nucleon knockout are given.

[Domestic injuries in childhood. Results of a survey carried out in a Sicilian area]

A retrospective investigation was performed with an anonymous questionnaire administered to the mothers of 2208 children aged between 3 and 11 years, randomly selected from the residents of three target areas: a country town, a residential and a popular quarter of a chief town (Catania, Sicily). Of the 2208 mothers in the three areas, 1151 completed the questionnaire with an overall response rate of 52.12%. In the last 6 months a large number of children (17.29%) suffered at least one accident at home. Predominating injuries were falls (71.86%) followed by cutting or stab-wounds (13.57%). The more frequent lesions were contusions (42.13%), wounds (29.95%) and fractures (14.22%). Almost the half of children victims of injuries required hospital care (44.72%). The majority of domestic accidents occurred in the bathroom (17.10%), in the kitchen (15.10%) and in the bedroom (10.55%). Fractures and wounds were more frequent among children aged 6-11 and 3-5 years, respectively. The highest frequency of domestic accidents among children of all ages living in the popular quarter (20.89%) and in the country town (19.18%) compared with those living in the residential quarter (11.67%) (chi2= 12,768, P<0.01) could be related to their lower socio-economic condition.

[Pancreatic pseudocysts. Clinical contribution]

Aim of this study was to compare, taking into consideration data from the literature, the various diagnostic examinations and therapeutic modalities nowadays available to manage patients affected by pancreatic pseudocysts. Personal experience regarding three patients with post-necrotic pancreatic pseudocysts is reported; these patients complained of epigastric pain with nausea and tenderness in the upper abdominal quadrants. Diagnosis was made by CT. In one case a progressive decrease of the pseudocyst was observed; the second patient was treated by a pseudocyst-jejunostomy; the last patient initially underwent a trans-gastric percutaneous drainage for infection of the pseudocyst and afterwards an open pseudocyst-gastrostomy. All patients were cured, even if the second patient during the postoperative course developed a pleuric effusion, which was treated by thoracentesis. Pancreatic pseudocysts in 20% of cases resolve spontaneously, as observed in one of our patients. In other cases, a surgical operation is needed, now feasible through an endoscopic, percutaneous, laparotomic or laparoscopic approach. The endoscopic and percutaneous approach are indicated only in selected cases, so that the "gold standard" treatment is still the laparotomic one, especially by a pseudocyst-jejunostomy, which also in our experience has given the best result. Very promising also, according to the latest data from the literature, seems the laparoscopic approach, by which a wide communication between the stomach and the pseudocyst is obtained.

Defects in GT rotary instruments after use: an SEM study

Used rotary nickel-titanium instruments require frequent replacement. This laboratory study evaluated defects of GT Rotary instruments before and after usage. The instruments were fixed into custom-made holders and photographed in an SEM at x 260 to x 12,000 magnification at preset points. Instrument sizes 20 with 1.0, 0.8, and 0.6 taper and instrument sizes 35 with 1.2 taper were used in 12 canals. The used instruments were cleaned and then reexamined in an SEM as before. The presence of 11 types of conditions was scored from the pre- and postusage photographs. No instruments fracturing or plastic deformation was observed during the test. The presence of debris, pitting, and scraping changed significantly. Imperfections were found on used GT Rotary instruments and the presence of defects (pitting, scraping, and blunt-cutting edges) increased in all of the instruments. The behavior of GT Rotary instruments with usage seems to be different, compared with that found in other instruments.

Wear of nickel-titanium endodontic instruments evaluated by scanning electron microscopy: effect of ion implantation

The present work analyzes possible increases in resistance to wear of nickel-titanium endodontic instruments that have undergone a process of ionic implantation. ProFile .04 taper #25 instruments were subjected to ionic implantation with bands of nitrogen ions of 250 KeV, currents in the order of 10 microA/cm2, and doses of 2 x 10(17) ions/ cm2. The instruments were used to make preparations in acrylic endodontic training blocks. Scanning electron microscopic investigations showed that after 60 s of work inside the endodontic training blocks nonionic implanted control instruments showed small modifications in their blades, and their tips showed the first signs of wear. After 240 s the control instruments showed consistent signs of wear and frequent changes to their surfaces. After 240 s of use the ionic-implanted instruments did not present any significant changes in the micromorphology of their surfaces. The implanted instruments did not manifest the typical signs of wear and did not show the surface changes that quickly affect the working life of untreated endodontic instruments manufactured from nickel-titanium.

The effect of surface treatments of nickel-titanium files on wear and cutting efficiency

OBJECTIVES

This study was designed to verify whether nitridation treatment of the cutting surfaces resulted in surface or subsurface changes that produced an increase in the resistance to wear in nickel titanium (NiTi) endodontic files.

STUDY DESIGN

Some experimental samples were exposed to ionic implantation by using 150 keV of nitrogen ions and doses of 1 x 10(17) ions per cm(2). Other samples were exposed to thermal nitridation processes performed for 480 minutes at 500 degrees C temperature. Control samples were not exposed to any process. The chemical composition of the surface layers of each sample was determined by means of x-ray photoelectron spectroscopy. The cutting efficiency was tested on an endotraining bloc.

RESULTS

The experimental instruments showed in-depth distributions of chemical composition that were different from those seen in the control group; thermal-nitridated instruments demonstrated a surface ratio of nickel to titanium of 0.5. Implanted samples had a higher N/Ti ratio (1.2); this ratio may be due to the presence of a layer of titanium nitride. Samples in the experimental groups showed an increase in cutting ability as compared with the controls.

CONCLUSIONS

Thermal nitridation and nitrogen-ionic implantation treatment of nickel-titanium files produced a higher wear resistance and an increased cutting capacity.

[Thermoelastic analysis of nickel-titanium endodontic files]

BACKGROUND

Technological progress in the endodontic field has allowed the creation of innovative nickel-titanium endodontic instruments, made with a superelastic alloy with a reduced modulus of elasticity. The elastic properties of the NiTi alloy can undergo significant variations in connection with mechanical movements and cyclic fatigue induced on the instruments caused by their repeated usage, especially in canals which are anatomically difficult to shape. The state of tension of the instrument determines a deformation of the geometry of the files and, therefore, a modification in their properties. Similarly to mechanical stress, thermal treatments can influence the properties of the alloy. The aim of the study is to subject the NiTi alloy to repeated thermomechanical cycles, examining the influence of the mechanical and thermal stress on the temperature at the beginning and end of the martensite transformation, on the increase of recovery of deformation during the cooling phase and on the change in the internal structure of the material.

METHODS

The instruments (30 ProFile Maillefer) were subdivided into 5 groups: Group I, composed of 6 new ProFiles submitted to 14 sterilization cycles in an autoclave for 30 minutes each; Group II, formed by 6 unused ProFiles subjected to one sterilization cycle in an autoclave; Group III made up of 6 new ProFiles used as controls; Group IV made up of 6 ProFiles submitted to clinical use on endodontic simulators in plexiglas for a total time of 240 seconds; Group V consisting of 6 ProFiles used on endodontic simulators for a total time of 480 seconds. All the above mentioned samples were tested using a thermomechanic dynamic analyzer (DMTA) produced by Rheometric Scientific.

RESULTS

The files from Group III (control) show an elastic deformation curve typical of nickel-titanium instruments. The samples from Groups IV and V subjected to sequential use on endodontic simulators evidenced modifications in their elastic behaviour compared to the control instruments. The operative use caused modifications in the original properties of the alloy, with a reduction in elasticity proportional to the number of uses. The instruments that underwent 14 cycles of sterilization in the autoclave (I group) present dynamic analysis curves which are different compared to the new unsterilized ProFiles. After 14 cycles there is a modification in the response of the instruments to thermodynamic stress.

CONCLUSIONS

Both the samples undergoing repeated mechanical stress on Plexiglas endodontic simulators and those sterilized in the autoclave at thermodynamic analysis show significant modification in modulus of elasti- city. The different taper does not influence the experimental results, there not being any significant differences found in the elastic behaviour between ProFiles.

[Non-Hodgkin lymphoma of the maxilla. Report of a case]

Lymphomas are primitive neoplasias of the lympho-reticular system and are classified into two principal categories: Hodgkin's lymphoma (HL) and Non-Hodgkin's Lymphoma (NHL) each classified into low, medium and high grades, according to their clinical and cytological characteristics. The treatment and prognosis of such neoplasias vary according to the distribution of the illness and to the moment of initial diagnosis. In NHL, treatment depends prevalently on the histological subtype. Over the last few years it has been possible to associate to defined nosographic entities a characteristic phenotype, and to formulate a phenotypical classification of chronic lymphoproliferating illnesses. The classification of the Working Formulation subdivides lymphomas into groups of increasing malignancy. In histological sections, non-Hodgkins lymphomas are relatively homogeneous, uniformly cellular and dominated by malign lymphocytes. The symptomatology of NHL can vary according to the different location. The clinical manifestation of NHL can be in the form of swelling or ulceration. In contrast with lymphonodal lymphoma, in which the spread through blood to distant lymphonodal regions or extra lymphonodal areas is rapid, the extra lymphonodal ones show a clinical course of illness comparable with those of carcinomas. The authors present the case of a 89 year-old patient with an ulcerated, non painful swelling in the upper right alveolar maxillary region, showing slow development, soft consistency and indefinite edges; this lesion did not affected the normal physiological functions of the stomatognathic apparatus, thus explaining why the patient had noticed the appearance of the process two years prior to the visit but had not reported it. The pathological case-history shows traumas at the site of the lesions due to dentures. At the moment of the visit, the ortopathomographic examination of the upper and lower dental arch shows the presence of a lesion in the right maxillary region, radiographically opaque, with ill-defined margins and signs of continuity with the homolateral maxillary sinus.

Effect of sterilization on the cutting efficiency of rotary nickel-titanium endodontic files

OBJECTIVE

Nickel-titanium instruments that offer greater flexibility than instruments made of other metallic materials have been developed. This study evaluated the behavior in vitro of nickel-titanium rotary instruments under repeated sterilization cycles.

STUDY DESIGN

To investigate changes in cutting ability and superficial alterations, 36 ProFile instruments, 18 with a taper of .04 and 18 with a taper of .06, were exposed to different sterilization cycles. Samples were divided into 3 groups of 12 files each. The 12 group A samples were exposed to 14 cycles of sterilization for 30 minutes; the 12 group B samples were exposed to 7 cycles of sterilization for 30 minutes; the 12 group C samples were not sterilized and served as a control group. Chemical compositions of the near surface layers of samples of each group were determined by means of Auger spectroscopy.

RESULTS

The instruments that underwent the greatest number of sterilizations (group A) showed in-depth distributions of chemical composition that were different from those seen in the control group; this was the result of greater amounts of titanium oxide on the surfaces of the sterilized instruments. The files of group A showed a decrease in cutting efficiency in comparison with those of the control group.

CONCLUSIONS

On the basis of this research on nickel-titanium files, we determined that repeated sterilizations under autoclave alter the superficial structure of such instruments.

[Von Recklinghausen osteitis fibrosa cystica. A clinical case]

In Recklinghausen's disease the skeleton lesions are often the first signal of the pathology. The main clinical manifestations are represented by bony lesions which appear as multicystic lesions with loss of the hard lamina and skull malformation and asymmetry. In this disease there is a relevant osteoclastic activity which prevails over the osteoblastic one associated to the fibrous substitution of the marrow, sometimes producing micro or macro cysts. The typical alteration consists of an increase along the endosteal and trabecular surfaces in the number of osteoclasts which can be found in small reabsorption gaps. This is the cause of a cortical and trabecular reduction which can appear as interrupted. Histologic lesions consist in the replacement of bone tissue with fibrous and osteoid tissue. These bony lesions are not characteristic of the disease but to be distinguished from other pathologies such as for example Paget's disease and other forms of fibrous dysplasia (Gardner's syndrome, Leontiasis ossea). A case personally observed is described: a women, 29 years old, suffering from Recklinghausen's disease with face and skull asymmetry, condyles and glenoid cavity deformation, abnormal face reduction. Observing the planigraphy on the right side of the temporomandibular articulation, flattened glenoid cavity and condyles with irregular outlines can be noticed, aplastic coronoid cuts, altered jaw. The patient was submitted to surgery for dental extraction followed by a biopsy which showed some regressive alterations on cellular level of the bony structure.

[Comparison of different finishing methods for composites and compomers. Profilometric analysis]

BACKGROUND

Reconstructions with aesthetical materials neither finished nor polished can be extremely irregular and wrinkled. For this reason they represent an ideal basis for the growing of pigmentation which come from food remainings and the nestle of bacteria on the plaque. The finishing of aesthetical materials is a fundamental step in conservative dentistry. The finishing session regarding the aesthetical restorations should be considered and planned at the moment of their insertion in the prepared hollows. The finishing should not be considered an option, but the conclusion of all the conservative treatment. Purpose of the search is to examine and assess, through a technical equipment measuring the superficial wrinkledness of the materials, the action of 4 systems of finishing and polishing on two aesthetical materials widely used in the daily practice by dental surgeons: a compomer (Compoglass, Vivadent) and a composite (Spectrum, Dentsply).

METHODS

For each of these two materials some little slabs model have been prepared, choosing the universal colour in the colorimetric scale. The two types of filling materials have been compared with 4 systems of finishing and polishing: Sof-Lex Pop-on (3M), Enhance system (Dentsply), Hawe Micro Disc (Howe Neos), Heawe Gommini Polisher (Heawe Neos). The total working time did not overcome 1 minute. The little slabs have been obtained, pressing the resin between two slides used in microscopy. In the hope to guarantee in the different samples, a uniform thickness, we have used a technical device. On each covering slide we have put a weight of 0.5 kg for 5 minutes. The thickness of the little slabs obtained was 2 mm. Thus, pressed between the two slides, the aesthetical material has been photopolymerized according to the time suggested by Manufacturing Industries. The sizes concerning the wrinkledness of samples subjected to different treatments have been carried out using a pointed profilometer with high sensitivity. (Tencor-P10). This instrument used in the National Laboratory of Catania, called INFN, is able to graphitize the wrinkledness of a surface "survbeying" it with a diamond ultramicrometric point.

RESULTS

All tested systems gradually produce the upper layers of the materials less suitable to resist the assault of plaque bacteria as time passed. The 3M coarse and medium grain Disks are very abrasive and for this reason the surface of the materials is ill-shaped. Those disks with fine and extra fine grain, smooth the tracks left by previous disks. As they have been always used according to their decreasing granulometry, the disks are used only for removing small composite pieces in excess and to improve micromorphology of the restauration. The "Gommini" are less abrasive than Disks. In a few minutes and often with only one step they produce a much regular and polished fillings surface.

CONCLUSIONS

The "Gommini" have a preference when the last photopolymerization has left a regular layer, with a very good micromorphology. Actually, "Gommini" do not remove much material, but they continue to smooth the outline of the reconstruction. Disks are not classified as being of first quality in the finishing of composites and compomers.

[Evaluation of two root canal preparation and obturation methods: the Mc Spadden method and the use of ProFile-Thermafil]

BACKGROUND

In endodontic field different instruments and techniques have been suggested for the preparation and filling or radicular bent canals. The purpose of this study is to compare two different cleaning and canal filling methods: preparation and filling technique, according to Mc Spadden's method, instrument technique and the closing of the canal system according to ProFile-Thermafil method.

METHODS

In this study ten molars divided into two groups of five elements each were used. The five molars of the first group were prepared according to the "crown-down" technique with nickel-titanium instruments by NT Engine Files Quantec 2000 series. The 18 canals found out in the five molars have been filled with Pac Mac and gutta-percha preheated. The five molars of the second group have 17 radicular canals which, firstly, have been cleaned with ProFile .04 and .06 taper fitted to a manipulator at 220 revolutions per minute and then filled by Thermafil n. 30 with plastic carrier. All ten molars were X-rayed first, during and after the treatment. All teeth were soaked into polymerised resin, dissected into three different points and observed through Optical Microscope.

RESULTS

Both cleaning techniques succeed in being efficient in bent canals. The instruments made by Mc Spadden highlight a greater preservation of canal dentine than the ProFile. In samples of the first group there is an excellent adaptation of multiphase gutta-percha to the canal walls and a correct relationship between the filling material and the apical foramen. In filling with Thermafil the adaptation of gutta-percha inside the radicular canal shows outstanding differences in relation to sections taken into account. Actually, while in portion of the crown the filling can be considered satisfactory towards the canal walls, in apical sections there is a decrease in the quantity of gutta-percha step by step, while a contact of plastic carrier with dentine walls is highlighted.

CONCLUSIONS

Wheter in the shaping or in the canal filling phase, the two methods are efficient and conservative towards dental structure at the same time. These methods, have an outstanding reduction in dental weakening and in times of the endodontic treatment performance.

[SEM (Scanning Electron Microscopy) study of the deterioration of ProFile .04 and .06]

BACKGROUND

The ProFile are endodontic instruments made by a special nickel-titanium alloy. They have to work on constant rotation at a speed of 350 revolutions per minute. The purpose of the study is to assess, through SEM research, a possible deterioration of different ProFile conicity.

METHODS

Sixteen dental elements pulled out for period dental reasons have been used as samples to assess the progressive deterioration of .04 and .06 ProFile conicity. Eight molars and eight premolars with a total of 36 radicular canals were examined. The types of ProFile tested were 8: they were respectively 4 with .04 conicity and 4 with .06 conicity. Before being used, all instruments are previously studied through SEM. The tested ProFile with .04 conicity had a diameter of 15, 25, 30 and 45. Those with .06 conicity had a diameter of 20, 25, 30 and 35. Each tested ProFile was introduced inside a radicular canal and was turned for 180 seconds with a constant rotation of 200 revolutions per minute. After this first step, the alterations produced by the instrument could be observed through SEM. Afterwards, the same ProFile has worked again inside another radicular canal with the same time and the same number of turns, before being observed again through SEM. We have continued using this method up to the break of the instrument.

RESULTS

The instruments with .04 conicity and smaller diameter are subject to a faster deterioration, more visible at the point. After a working time of 180 seconds all the instruments have their distinct morphological alterations: after other 180 seconds it is possible to often observer an alteration to the pitch of the instrument. The breaking times are related to the diameter and conicity of ProFile tested.

CONCLUSIONS

Endodontic nickel-titanium instruments, even if they represent a progress in the field of canal preparation, undergo some alterations in their shape if they are put under inevitable mechanical stress. The damages can be: break at the top of the instrument and loss of cutting abilities at the turns level.

[Recklinghausen neurofibromatosis. Report of a case]

Neurofibromatoses are genetic disorders of the nervous system that primarily affect the development and growth of neural cell tissues. These disorders produce other abnormalities such as skin changes and bone deformities. Neurofibromatoses occur in both sexes and in all races and ethnic groups. Scientists have classified these disorders as neurofibromatosis type 1 (NF1) and neurofibromatosis type 2 (NF2). Other types of neurofibromatoses may exist, but are not yet identified. Nearly 50% of the cases shows a well definited familiarity for the disease, according to an autosomal dominant transmission, while the other 50% of patients shows a negative history of familiarity, according to a new chromosomal mutation interesting the same autosomal genes of the dominant transmission. Oral localization is more rare showing an incidence ranging from 4 to 7% in most series of different authors. The most frequent involvement site in oral neurofibromatosis is the tongue, followed by the oral mucosa and floor of the mouth; palate and maxillary-mandibular bones are a rare localization of the disease. In the present, the clinical, radiological, histopathological and therapeutical aspects of a clinical case of neurofibromatosis, presenting as mandibular tumor, are examined. The clinical case reported, a 37 year old man, was essentially characterized by a positive family history for the disease, a neurofibroma of the oral mucosa.

[The role of cell adhesion molecules in the formation of periapical granulomas]

Cell adhesion molecules (CAMs) are cell surface proteins involved in the binding of cells, usually leukocytes, to each other, to endothelial cells, or to extracellular matrix. Specific signals produced in response to wounding and infection control the expression and activation of certain of these adhesion molecules. The interactions and responses then initiated by binding of these CAMs to their receptors/ligands play important roles in the mediation of the inflammatory and immune reactions that consult one line of the body's defense against these insults. Most of the CAMs characterized so far fall into three general families of proteins: the immunoglobulin (Ig) superfamily, the integrin family, or the selectine family. Recent studies have indicated that selectins (E,L,P) are implicated in cell trafficking, an important aspect of inflammation-related process. Regulation of white blood cell trafficking from the blood vascular compartment to regions of pathogenic exposure is one of the most important functions of the immune system. The distinct phases of leukocyte migration include: rolling, activation, firm adhesion, transendothelial migration and subendothelial migration. The selectins have been implicated in the first step of this cascade. An inflammatory response is first evoked in the pulpal tissue in an attempt to neutralize the injurious agent and to dispose of damaged tissue and cells. The pulpal vessels dilate and blood flow to the tooth increases. At the same time, permeability of the vessels increases allowing leakage of fluid and leukocytes into the tissue.

[Cell communication in the development of the oral cavity]

The cadherins are a family of a calcium-dependent cell adhesion molecules that are regulated both spatially and temporally during development. Epithelial cadherin (E-cadherin) is present in the epithelial cells in both the embryo and yolk sac during organogenesis. In many studies, the presence of E-cadherin was analyzed during normal and disturbed craniofacial development with respect to palate and tooth formation. E-cadherin was present in epithelia of both ectodermal and endodermal origin. The expression level of E-cadherin increased with age and differentiation. The expression pattern of E-cadherin implies that this molecule has a role during normal development of the epithelia of the cranio-facial complex. Morphogenesis and cell differentiation in the developing tooth are controlled by a series of reciprocal interactions between the epithelial and mesenchymal tissues. The exact molecular mechanisms operating in these interactions are unknown at present, but both structural components of the extracellular matrix (ECM) and diffusible growth factors have been suggested to be involved. In this review article we summarize our findings on the distribution patterns of three ECM molecules and two cell surface receptors during tooth morphogenesis through bud, cap, and bell stages of development. The examined molecules include fibronectina and tenascin, which all represent components of the mesenchymal ECM, the cell surface proteoglycan, syndecan, which functions as a receptor for interstitial matrix. Based on the observed changes in distribution patterns and on experimental evidence, roles are suggested for these molecules in epithelial-mesenchymal interactions during tooth development. C-Cam is a cell surface glycoprotein that is involved in cell adhesion and may play a role in histogenesis and organogenesis. It is a member of the carcinoembryonic antigen (CEA) gene family, which is a subfamily of the immunoglobulin gene superfamily. The presence of C-CAM in all proliferating craniofacial epithelia indicates that this molecule may play an important role in development.

[Changes in the biological and immunologic parameters in the oral cavity of the aged. Review]

Senescence is the effect of the immune system incapacity to see "self" and "non-self"; timo-involution induced down-regulation of immunoregulatory -T and B-lymphocytes. Immunosenescence mutations in oral cavity are examined. Even the oral ecosystem presents disorders in quality and quantity of the bacterial plaque and a different immune response. Age senescence is particularly evident in the masticatory apparatus, in fact the dental tissues have remarkable morpho-structural physiological changes; the epithelial, connective and osseous tissues of the periodontium have structural age changes related to the collagen synthesis and physical properties, with an increase of the stroma and a decrease of cell population. The osseous tissue presents cellular atrophy, sclerosis, osteoporosis and is undergoing a continuous structural remodelling; the oral mucous membranes show a thinning of epithelium and an increase of the stroma related to the parenchyma. Specific individual changes could be appraised in the involution of stomatognathic apparatus, more than an indefinite reduction of the performances.

[Oral lesions in systemic lupus erythematosus. I. The etiopathogenic aspects of lupus erythematosus]

The authors investigate lupus erythematosus systemicus, characterized by the multiform etiology and autoimmune pathogenesis. Cutaneous lesions, large confluent areas of erythema, poikilodermatous lesions, atrophy and necrotizing vasculitis (leukocytoclastic vasculitis) occur in patients with lupus erythematosus (SLE). Ulcerative lesions are an ACR (American College of Rheumatology), (formerly ARA), criterion for the diagnosis of SLE. These lesions are suspected of being caused by a mechanism involving circulating immune complexes and neutrophils. This observation further supports previous evidence that all oral lesions in SLE result from vacuolar degeneration of basal keratinocytes. Immunopathologic study of lupus erythematosus shows the correlation between HLA-dr positive keratinocytes or Langerhans cells and epidermotropic T cells and the immunobiological significance of the antigen-antibody system in LES.

[Oral lesions in systemic lupus erythematosus. II. The clinical and therapeutic aspects of lupus erythematosus]

The authors describe the most common clinical characteristics and main parameters of SLE. They describe the currently most therapeutic protocol with particular reference to circulating immune complex study on patients with SLE, and they examine different prospects of applicability and of prognostic result. The aim of this paper is to provide an outline of the clinical diagnosis and the immunobiological significance of the nucleoprotein autoantibodies and of the Ro/SSA antigen-antibody system and the relationship between circulating anti Ro/SSa antibody levels and skin disease activity in SLE.