The mechanical behavior of high-translucent monolithic zirconia after adjustment and finishing procedures and artificial aging.

Statement Of Problem: How occlusal adjustments and finishing of high-translucent monolithic zirconia restorations affect their mechanical behavior is unclear.

Purpose: The purpose of this in vitro study was to investigate the effect of grinding, finishing, and hydrothermal degradation on the roughness, flexural strength, and reliability of fully stabilized zirconia (FSZ) and partially stabilized zirconia (PSZ) for monolithic restorations.

Material And Methods: Specimens of PSZ and FSZ were divided into 5 groups: control (Ctrl); those ground by using coarse diamond rotary instrument (Gr); those that underwent grinding, polishing (diamond rubber), and glazing (GrPolGl); those that underwent grinding and glazing (GrGl); and those that underwent grinding and polishing (GrPol).

Fatigue behavior and surface characterization of a Y-TZP after laboratory grinding and regeneration firing.

This study evaluated the effect of grinding and regeneration firing on the flexural fatigue limit and surface characterization of Lava™ Y-TZP ceramic. Forty bar-shaped specimens with 20 × 4.0 × 1.

Zirconia changes after grinding and regeneration firing.

Statement Of Problem: Despite improvements in computer-aided design and computer-aided manufacturing (CAD-CAM) systems, grinding during either laboratory procedures or clinical adjustments is often needed to modify the shape of 3 mol(%) yttria-tetragonal zirconia polycrystal (3Y-TZP) restorations. However, the best way to achieve adjustment is unclear.

Purpose: The purpose of this in vitro study was to evaluate the microstructural and crystallographic phase changes, flexural strength, and Weibull modulus of a 3Y-TZP zirconia after grinding with or without water cooling and regeneration firing.

Effect of Grinding and Resintering on the Fatigue Limit and Surface Characterization of a Y-TZP Ceramic.

This study evaluated the effect of grinding protocols and resintering on flexural fatigue limit and surface characterization of LavaTM Y-TZP. Bar-shaped specimens (20×4.0×1.

Working postures of dental students: ergonomic analysis using the Ovako Working Analysis System and rapid upper limb assessment.

Background: As dentistry is a profession that demands a manipulative precision of hand movements, musculoskeletal disorders are among the most common occupational diseases.

Objectives: This study estimated the risk of musculoskeletal disorders developing in dental students using the Ovako Working Analysis System (OWAS) and Rapid Upper Limb Assessment (RULA) methods, and estimated the diagnostic agreement between the 2 methods.

Methods: Students (n = 75), enrolled in the final undergraduate year at the Araraquara School of Dentistry--UNESP--were studied.

Effects of 0.2 T static magnetic field on human skin fibroblasts.

Human skin fibroblasts were exposed to 0.2 T static magnetic field generated by a magnetic resonance tomograph. After 1h exposure, cell morphology was modified in association with a concomitant decrease in the expression of some sugar residues of glycoconjugates.

Association between atmospheric ozone levels and damage to human nasal mucosa in Florence, Italy.

We evaluated the effects of urban air pollutants on human nasal mucosa over an 8-month period on 102 subjects living in Florence, Tuscany, Italy. A group of subjects living in a city with a lower level of pollution (Sassari, Sardinia, Italy) was also analyzed. Nasal mucosa cells were harvested by brushing, a noninvasive procedure.

Stomal recurrence following total laryngectomy: clinical and molecular analysis of a series.

The aim of the present study was to analyze the risk features and to discuss the preventive measures and treatment of stomal recurrence (SR) after total laryngectomy (TL), and to investigate the clonal relationship between the primary and recurrent lesions. We reviewed a series of 25 patients affected by SR after TL for laryngeal squamous cell carcinoma. A subset of 7 coupled primary and recurrent carcinomas were examined for microsatellite alterations that were used as a marker of genetic lineage.

Sclerosing stromal tumor in an accessory ovary.

Background: An accessory ovary is an uncommon congenital anomaly of the female reproductive tract. Tumors arising in ectopic ovaries are extremely rare.

Case: This 18-year-old woman had a pelvic tumor attached to the right ovary which was solid cystic and lobulated and histologically and immunohistochemically showed the appearances of sclerosing stromal tumor, a benign entity.

Primary carcinoma of the subglottic larynx.

Primary cancer of the subglottic region is very rare and delay in diagnosis often leads to a poor prognosis. We retrospectively reviewed 49 patients with primary cancer of the subglottic larynx observed from 1969 to 1993 in the ORL Clinic of the University of Florence. This number constitutes 1.

Coughing in laryngectomized patients.

Ablation of the larynx implies withdrawal of afferent information from receptors involved both in the control of expiratory flow and in the genesis of protective airway reflexes including coughing. To investigate the effects of laryngectomy on the sensory and motor component of coughing, maximal voluntary cough (MVC) efforts as well as the reflex cough (RC) responses at threshold (T) and suprathreshold (1.8 x T, ST) levels induced by inhalation of progressively increasing concentrations of ultrasonically nebulized distilled water (fog) were analyzed in 10 laryngectomized patients and 10 control subjects.

Parotid gland carcinoma: analysis of prognostic factors.

The histologic variety of parotid gland carcinomas, their different natural history, and the peculiar anatomy of the parotid region can make prognosis and therapeutic strategy quite controversial. The present study was designed to evaluate those prognostic factors able to affect the long-term results in a group of 167 consecutively treated parotid epithelial malignancies. The continuous or discrete covariants considered as potential prognostic factors are age, sex, histotype, grading, TNM and pTNM classification, facial nerve involvement, type of surgery on the tumor site and on nodes, facial nerve resection, and postoperative radiotherapy.

Presence and location of endothelin and endothelin-binding sites in human nasal mucosa under normal and metaplastic conditions.

The presence and site of production of endothelin-1 (ET-1) was investigated in biopsies obtained from the nasal mucosa of 10 healthy human subjects and 10 patients affected by chronic rhinitis. The presence and localization of receptors for ET-1 was also investigated. Bioptic fragments were examined by scanning electron microscopy.

Cyclooxygenase and lipoxygenase metabolite generation in nasal polyps.

A role of prostaglandins (PGs) and leukotrienes (LTs) in the pathogenesis of nasal polyps has been recently suggested. Cyclooxygenase (CO) products (thromboxane B2, PGE2 and 6-keto PGF1 alpha) and lipoxygenase (LO) products (LTB4 and LTC4) were investigated by radioimmunoassay in polyps, hypertrophic turbinates and nasal mucosa from 14 patients with non-allergic (n = 6), allergic chronic rhinitis (n = 6) and aspirin-sensitive asthma (ASA) (n = 2), who underwent polypectomy. In all tissues CO metabolite levels were found higher than LO products (P < 0.

Multiple neurinomas of the parapharyngeal space.

The authors describe a rare case of three neurinomas arising in the parapharyngeal space. In spite of the large extension of the neoplasms, the only symptom reported by the patient was some dysphagia. Magnetic resonance imaging allowed us to identify the three masses and suppose their diagnosis.

The human nasal mucous membrane during chronic inflammation, before and after muco-active therapy: a study using scanning electron microscopy.

Chronic inflammation seems to induce alterations in nasal mucosa morphology. The type and extent of these alterations seem to be directly correlated with the duration of the inflammation. This study was carried out to ascertain whether the administration of muco-active drugs could modify these alterations by inducing their total or partial regression.

Scanning electron microscopic study of nasopharyngeal carcinoma.

The study has been carried out on biopsies taken from four patients affected by squamous cell carcinoma and four patients affected by undifferentiated carcinoma of nasopharyngeal type (UCNT). Three healthy volunteers have served as controls. All the specimens have been studied by SEM.

[Comparison of the results of surgery and radiotherapy in 175 cases of T2 glottic carcinoma: 116 operated and 59 irradiated cases].

The results were analyzed of 175 patients with glottic squamous cell carcinomas who were treated with curative purposes (1970-1986). One hundred and sixteen of them underwent surgery at the Otolaryngology Department of the University of Florence, and 59 were treated by radiation therapy at the Florence University and Hospital Departments of Radiotherapy. In the surgical series 78 cases were treated with radical surgery and 38 with conservative surgery.

Beneficial effects of intranasal applications of capsaicin in patients with vasomotor rhinitis.

Capsaicin, a nonenamide derived from Capsicum plants, has proven useful in patients with vasomotor rhinitis. In the present study, we studied the effects of 15 micrograms capsaicin suspended in 100 microliters solution in patients with known vasomotor rhinitis. Drug was given 3 times/day for 3 days to each patient by means of a spray delivered to the nasal mucosa.

[Scanning electronic microscopy study of nasopharyngeal carcinoma].

The nasopharyngeal carcinoma is a greatly interesting model of study. Its morphology has been studied in 8 patients affected by squamous cells carcinoma (4 cases) and by undifferentiated carcinoma (4 cases). By means of a fibre-optic pharyngoscope equipped with mechanical biopsy forceps, biopsies have been taken and subsequently studied by scanning electron microscopy (SEM).

Total parotidectomy--a routine treatment for parotid gland swellings?

The results of 25 years of quasi-routine total parotidectomy performance are shown. At the Department of Otolaryngology of the University of Florence, 582 patients were treated as follows: on 527 occasions by total parotidectomy with facial nerve preservation; 24 occasions by lateral lobectomy; 27 occasions by total parotidectomy with removal of the whole facial nerve; four times by enucleo-resection of the disease. Benign tumours were 378; primary and metastatic malignant tumours--100; non tumoral lesions--104.

Study of the nasopharynx in man by scanning electron microscopy.

To date only few and often disagreeing studies about human nasopharynx are available. The present research has the purpose to give a contribution to the knowledge of nasopharyngeal epithelium using S.E.