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Biomedical subjects

A Azzopardi

Publications and source records attributed to A Azzopardi.

18 recordsLinked to original sources
PubMed2004

The surface effects of erosion and abrasion on dentine with and without a protective layer.

OBJECTIVE: The aim of this in situ study was to investigate with four imaging modalities whether covering dentine with adhesive resins could protect against erosion from acids. The objectives were to observe and quantify the effects of acids and the soft tissues, especially the tongue, on dentine and the bonding agents using four assessment techniques: qualitative assessment with SEM, surface roughness and thickness of resin with the TSM and volume loss with the laser profilometer. DESIGN: An in situ investigation using extracted dentine sections embedded in splints held on the palate of 10 volunteers. The dentine sections were protected by two resins and subjected to a tooth wear regime. RESULTS: Both Seal and Protect and Opitbond Solo protected the tooth surfaces from a tooth wear regime. There were no statistical differences between the control surfaces and those protected with dentine bonding agents for resin thickness, roughness and profilometry. The appearance of the slabs under both confocal and SEM showed that the material remained in place despite a vigorous wear regime and therefore protected the tooth surface. CONCLUSIONS: For patients with uncontrolled erosion or tooth wear, applying a dentine bonding agent to exposed dentine is a practical option to prevent further damage.

Adult↗
PubMed2001

The measurement and prevention of erosion and abrasion.

OBJECTIVES: To develop a reproducible method to measure tooth wear and assess the protection given by dentine bonding agents in an erosive/abrasive wear regime. METHODS: Seal and Protect (Dentsply, UK) and Optibond Solo (Kerr, UK) were each applied to 20 extracted teeth and subjected to 3000 cycles in a reciprocating erosion/abrasion wear machine. A further 20 teeth, without protection, were subjected to the same wear regime and were either brushed in water or immersed in acid. Impressions were taken by a standardised technique and were scanned with a non-contacting laser profilometer. The amount of erosion was measured at the same co-ordinates before and after erosion using 2mm diameter metal discs as reference points. RESULTS: The amount of wear on Seal and Protect had a mean 24.8 microm (SD 57.4 microm) and for Solo it was 1.4 microm (24.5 microm), and this difference was statistically significant (p=0.02). There was no statistically significant difference in the wear measured on the teeth brushed in water or immersed in acid. The wear measured on the unprotected teeth was 243 microm (SD 120 microm) and was statistically significantly different to the protected surfaces (p=0.001). CONCLUSION: Both Seal and Protect and Solo protected the teeth in this wear regime and the technique could be used clinically for patients with uncontrolled dental erosion.

Analysis of Variance↗
PubMed2001

Real-time confocal imaging, during active air abrasion -- substrate cutting.

Air abrasion cutting, using particulates accelerated in a controlled compressed gas stream, is currently being re-evaluated as a precision tissue removal technique for dental cavity preparation. The minimal vibrations and heat generated during cutting commend the technique for use in the shaping of fragile or brittle materials that are vulnerable to vibrations and thermal stresses. Traditional air abrasion studies have relied solely upon post-procedure imaging, and cutting process details have been inferred from the nature of the residual surface. In this paper, however, a real-time confocal microscopic imaging method is described, which for the first time has allowed prior target structure characterization with subsequent imaging of cutting interactions and substrate failure patterns. Using internally focusing long working distance Hill objective lenses, focusing deep to a protective microscope slide and adhesive interfaces, unhindered remote image sampling within the bulk of specimens such as tooth tissue, acrylic and brittle ceramics was possible. Moreover, areas of active cutting and inactive regions were identified within air abraded cavities during their creation. The characteristics of the finished cut surfaces were demonstrated and confirmed the findings of previous SEM studies. The method allowed direct control over all the known variables influencing cutting with particulate streams.

Air Abrasion, Dental↗
PubMed2000

The shrinking seminoma--fact or fiction?

We report 2 cases of testicular seminoma with unusual but dissimilar clinical presentations, which may represent different stages of spontaneous regression of a primary testicular seminoma, the so-called 'shrinking seminoma'. The aetiology of this phenomenon is discussed. These cases also illustrate that, like enlargement, reduction in the size of a testicle warrants investigation for malignancy.

Adult↗
PubMed2000

A literature review of the techniques to measure tooth wear and erosion.

This paper reviews methods to measure tooth wear especially those more recently introduced as a result of improvements in technology. The review searched methods to measure tooth wear and dental erosion from large epidemiological investigations, in vitro and in vivo studies. There seems to be wide variation in techniques used to measure tooth wear and erosion. In vitro techniques may have little direct clinical relevance but can lead to new and more accurate clinical methods. In vivo studies have problems with reference points and accurate validation of the techniques. There is a need for a simple, reliable technique to quantify tooth wear due to erosion.

Diagnostic Imaging↗
PubMed2000

Confocal and multi-photon microscopy of dental hard tissues and biomaterials.

Confocal microscopy is a technique that can be used both in the clinic and the high-resolution microscopy suite. This form of optical microscopy enables high-resolution images to be made of samples with minimum requirements for specimen preparation. Images may be made of either reflections from the sample surface or, if an immersion medium is used to optically couple the objective lens, then sub-surface images can be produced of reflective or fluorescent structures within semi transparent materials such as cells and dental hard tissues. These images are like optical sections, giving thin (> 0.35 microm) slices up to 200 microm below the surface of a mineralized tissue. The technique generates significant improvements in resolution, lying somewhere between that of conventional light microscopy and TEM/SEM. Instruments that work at video-rate allow high-speed events to be examined, such as in vivo clinical studies, cutting of dental tissues and fracture of adhesive interfaces. New dyes offer many exciting prospects for labeling changes in chemical composition in materials or biological tissues, while new imaging techniques such as multi-photon laser excitation of dyes give the potential of greater depth penetration and improved resolution. As with all new techniques the inexperienced should be aware of some of the artifacts inherent to the system. However, the widespread availability of conventional confocal microscopes should give ample opportunity for dental researchers to capitalize on this new technology.

Artifacts↗
PubMed1998

Prostatic infarction/infection in acute urinary retention secondary to benign prostatic hyperplasia.

PURPOSE: We assess the role of acute prostatic infarction and prostatic inflammation in causing acute urinary retention in patients with benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: A prospective controlled clinicopathological study was undertaken comparing 35 patients who presented with acute urinary retention secondary to BPH with another 35 patients with symptomatic BPH. All 70 patients were treated with transurethral resection. The prostatic chips in each group were examined by 1 histopathologist, who was unaware of the clinical presentation of the patient, for changes of infarction, acute and chronic inflammation, and predominant histological pattern. RESULTS: There was a higher incidence of glandular pattern in the retention group compared to a stromal pattern in the control group, which was statistically significantly different (p < 0.001). A 5-fold higher incidence of prostatic carcinoma was noted in the acute retention group, which was also statistically significant (p < 0.05). CONCLUSIONS: Prostatic infarction and inflammation had no role in the etiology of acute urinary retention due to BPH.

Acute Disease↗
PubMed1997

Benign polyps with prostatic-type epithelium of the urethra and the urinary bladder.

The clinico-pathological features of nine urethral and urinary bladder polyps with prostate-type epithelium are described. The average age of the patients was 46 years. Three patients previously had cystoscopy and the lesion was not noticed on the initial examination. The commonest presentation in this series was haematuria, dysuria and frequency of micturition. One patient presented with postmicturition dribble and another with haemospermia. The polyps contained acini and papillae lined by prostate-type epithelium which was confirmed by immunohistochemical tests for prostate specific antigen and prostate acid phosphatase. In this series no age versus location relationship could be established. Symptoms resolved following resection or initial biopsy followed by fulguration. Recurrence is extremely rare.

Acid Phosphatase↗
PubMed1996

Interstitial cystitis in men.

Interstitial cystitis is an uncommon disease reported predominantly in females. Recently we were involved in the management of 4 men who had the clinical, endoscopic and pathological features consistent with the diagnosis of interstitial cystitis. The rarity of occurrence of the disease in males prompted us to report these cases.

Cystitis, Interstitial↗
PubMed1996

Malignant mesothelioma of the tunica vaginalis testis diagnosed by aspiration cytology--a case report with review of literature.

A case of malignant mesothelioma of the tunica vaginalis testis diagnosed by preoperative cytology of hydrocele fluid is reported. In our view this is only the second case diagnosed by preoperative cytology. The unique feature of this case, the characteristic ultrasound appearance, was recognized and confirmation by aspiration cytology led directly to radical orchiectomy, thus avoiding hydrocelectomy, hemiscrotectomy and possible local recurrence. Aetiopathogenesis and management options of this rare tumour are discussed, with a review of the literature.

Aged↗
PubMed1992

Giant pre-sacral neurofibroma.

We report a case of pre-sacral neurofibroma diagnosed on a routine medical examination. The pathological features and management criteria of these rare tumours are discussed.

Humans↗