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M Giannoni

Publications and source records attributed to M Giannoni.

At least 19 recordsLinked to original sources
PubMed1999

[Use of Electronic Spin Resonance in the study of dental enamel caries. Preliminary results].

BACKGROUND: By means of the Electron Spin Resonance technique (EPR) it is possible to detect carbonate-related paramagnetic centers in human tooth enamel. Several arguments indicate that the radicals formed after X-ray irradiation (CO2- and CO3(3-)) are ascribed to carbonate which is the most important constituent of hydroxyapatite. There is experimental evidence that the distribution of the orientation of these centers is related to microcrystal alignment in dental enamel, which might be responsible for caries susceptibility. The results reported in the literature, however, should be interpreted very carefully. METHODS: In our own preliminary research we studied twenty-seven samples of dental enamel taken from the buccal face of upper molars. Fifteen were carious and the other ones were sound. We used the R-parameter and the S-parameter to convert our experimental results into numerical values. The R-parameters, as introduced by Cevc et al. (1976-1980) is the ratio of the amplitude for the high field and the low component of the EPR signal. The S-parameter is the ratio of the amplitude of the A2 component and the low one. RESULTS: No significant difference was found between the R and S-value of carious and sound dental enamel samples. The degree of microcrystal alignment in enamel of clinically sound upper molar from their buccal site is very high. However, this result is not sufficient to evaluate the caries susceptibility or the caries resistance of tooth enamel. CONCLUSIONS: Therefore, we can conclude that it is not sufficient to ascribe the caries susceptibility to the R-value, because other factors (such as etiological factors and the structure of the teeth) should be considered.

Dental Caries↗
PubMed1999

[Polishing of composite resins. Instrumental notes].

BACKGROUND: The polishing is the last procedure in the application of composite fillings. The surface morphology and the marginal seal, that are indispensable for integration of composite fillings with dental tissue and oral environment, are tightly dependent on polishing procedure. METHODS: The authors tried out experimental therapeutic procedure in order to examine the surface of any composite resin polymerizated under matrix on a slide before and after polishing made by abrasive disease and finally after application of a new resin layer on a polished composite surface. These composite surfaces was examined with AFM and SEM. RESULTS: The images prove that in the polished specimens there is a restoration of composite morphology surface because of the partial removal of organic part during the polishing. The polymerization of a new resin layer on polished surface make this one more regular and even as a substitute for partial removal of organic part during the polishing. CONCLUSIONS: The experimental procedure prove that the ideal composite surface is that polymerizated under matrix because every treatment on this surface affect the composite filling's quality.

Composite Resins↗
PubMed1996

[Single-contrast enema after colon lavage in the elderly patient].

Double-contrast enema is often unsuccessful in elderly patients because of their poor cooperation and colon cleaning. This work was aimed at showing that a well-done single-contrast exam with simple colon lavage can make a very good alternative to double-contrast enema in elderly patients. Thus, 66 consecutive elderly patients (age range: 70-90 years) were submitted, over a 6-month period (June-December, 1994), to single-contrast enema, after colon cleaning with oral whole-gut lavage, using an osmotically balanced electrolyte solution (Isocolan, Bracco) containing polyethylenglycol (PEG 4000). We examined, in each patient: a) the tolerance to and effectiveness of bowel cleaning, according to the liquid volume drunk by each subject, needed to obtain clear diarrhea; b) radiograph quality. Successful colon cleaning was achieved with a mean (2.5-3 liters) and a large (3.5-4 liters) amount of solution, in 80% and 20% of our patients, respectively. Tolerance was good in the whole series except for 3 patients with emesis. Moreover, radiograph quality was good in 85% of the subjects. Finally, barium enema results, compared with endoscopic results, yielded 27 true positives, 3 false negatives (small neoplastic lesions) and 1 false positive. Therefore, in our opinion, these results confirm the role of single-contrast enema, combined with gut lavage, in elderly patients.

Age Factors↗
PubMed1995

[Epidermoid carcinoma of the oral cavity. Considerations of the role of the papillomavirus].

Human papilloma virus (HPV) may have an important role in oral carcinoma etiology. Our work compares the presence of HPV in the epithelium of oral mucosa of patients with oral carcinoma with other factors of risk (smoking, alcohol, chronic mucosal trauma). We studied 33 patients operated for oral cancer at St. Salvatore Hospital in l'Aquila, in January-December 1990. The presence of HPV was proved by a direct valuation of morphological signs (coilocytosis, nuclear inclusions, etc.) and by immunohistochemical technique with primary antibodies against structural virus antigens. Among the 33 patients 19 (57.6%) were positive for HPV and 14 (42.4%) were negative. Among the HPV positive subjects 13 were smokers, 11 usually assumed alcohol and 6 had chronic mucosal trauma. Among the HPV negative subjects 9 were smokers, 7 assumed alcohol and 3 had chronic mucosal trauma. The statistical evaluation of data showed the lack of significance of viral infection compared to other factors of risk. In spite of a few cases examined, we suppose that HPV doesn't play a primary role in oral cancerogenesis, but is a concomitant cause with other factors of risk.

Adult↗
PubMed1994

Color Doppler sonography of salivary glands.

OBJECTIVE: We used color Doppler sonography to evaluate the vascular anatomy of the salivary glands and to analyze physiologic changes that occur during salivary stimulation in normal subjects and the flow alterations that occur in diseased glands. SUBJECTS AND METHODS: The vascular appearance of the three major salivary glands was examined in healthy volunteers (n = 24); in patients with chronic autoimmune diseases, including Sjögren's syndrome (n = 23) and salivary sarcoidosis (n = 2); and in a variety of benign (n = 49) and malignant (n = 13) nodules. Physiologic changes were assessed in healthy volunteers by means of a stimulation test with lemon and were quantified with color images and spectral analysis. Tumor vascularity was graded on a four-step analog scale of 0 to (+3) and classified as either peripheral or hilar, depending on the distribution of vessels. RESULTS: In the control subjects, color Doppler imaging accurately reflected the complex vascular anatomy of the salivary glands and showed dramatic changes occurring in parenchymal vessels during lemon stimulation as a result of the intense hyperemia associated with the secretion of saliva. Sjögren's syndrome and sarcoidosis showed a diffuse hypervascular pattern when morphologic changes of salivary parenchyma were seen on gray-scale sonograms. Benign tumors showed a lower grade of vascularity than did malignant tumors. All but one of the hypovascular nodules graded as 0 (n = 8) and + (n = 23) were benign. Conversely, eight of 11 nodules labeled with the highest grade of tumor vascularity (+3) were malignant. When the pattern of tumor flow signals was peripheral, it could be considered specific enough to aid in diagnosing pleomorphic adenoma. Peak systolic velocities greater than 60 cm/sec were never detected in benign tumors and were seen in only 44% of malignant tumors. CONCLUSION: Color Doppler sonography is a promising technique for analyzing the vascularity of the salivary glands and for characterizing some pathologic conditions. Our experience suggests that color Doppler sonography can provide additional diagnostic information in patients with chronic inflammatory diseases or suspected malignant tumors and can help in differentiating pleomorphic adenomas from other salivary gland tumors.

Adult↗
PubMed1992

[Echography in laryngeal tumors].

During sonographic (US) studies of the neck for the nodal staging of patients with laryngeal neoplasms, the authors observed that, especially in advanced cases, also the primary lesion could be imaged with this method. Therefore, US capabilities were investigated in assessing the local stage of laryngeal neoplasms; the results were compared with clinical and surgical findings. Fifty normal subjects of various ages were previously examined to assess the normal US anatomy of laryngeal structures. The presence of calcifications within the thyroid cartilage is the major obstacle to US imaging of the larynx and is directly related to age; indeed, only 40% of subjects can be examined at the age of 70. Seventeen patients with advanced laryngeal tumors were examined by US. Laryngeal imaging was possible, either in part or completely, in 16 of 17 cases. The results were in agreement with clinical staging in 14 cases; in 2 cases US proved clinical understaging by detecting lesion spread to anterolateral perilaryngeal structures. To conclude, US is not suggested as the method of choice in patients with laryngeal neoplasms. However, in subjects with advanced tumors, also US can image the lesion directly, and even detect tumor spread to surrounding tissues, especially in the anterior and lateral directions. In a few cases, this can contribute to preoperative staging and to select the correct therapeutic approach.

Adolescent↗
PubMed1992

[Artifacts in echo-Doppler and color-Doppler].

It is well known that artifacts can be observed during US examinations; the same is true also for Doppler and color-Doppler images of blood flow. Recognizing these artifacts is important to avoid image misinterpretations and, when possible, to overcome them by modifying either techniques or unit settings, or both. This work was aimed at presenting the several artifacts which can be observed during Doppler investigations, at classifying them, and trying to understand the physical and/or technical principles underlying their origin. Doppler and color-Doppler artifacts can be divided into four large groups: 1) artifacts regarding evaluation of the presence of flow; 2) artifacts regarding evaluation of the direction of flow; 3) artifacts regarding determination of the velocity of flow; 4) artifacts affecting spatial location, on the screen, of the examined vessel. Each of the above can cause severe diagnostic misinterpretations, if not correctly recognized and interpreted. It must be kept in mind that an accurate analysis of unit settings during scanning, and the meticulous evaluation of the obtained color images are of the utmost importance for the proper use of this valuable but difficult diagnostic technique.

Artifacts↗
PubMed1991

[Papilloma of the palate. Clinical and histopathology].

An asymptomatic, exophytic and unusually large mass of hard and soft palate is presented. Its papillary surface architecture is characteristic of an oral squamous papilloma. The cause is unknown. Recurrent or malignant change, or both, are possible.

Adolescent↗