Tensile bond strength of four denture resins to porcelain teeth with different surface treatment

PURPOSE: This study evaluated the bond strength between porcelain denture teeth (Bioblend 43D) and four different polymerized denture resins (Lucitone 199, Palapress, Acron MC, Triad) with and without a bonding agent and after four different types of surface treatment (polished, HF etched, sandblasted, air-abraded). MATERIALS AND METHODS: Central incisor porcelain denture teeth were divided into 32 groups of 5 each. Tensile bond strength (MPa) was determined using a testing machine at crosshead speed of 0.5 mm/min. Mean and standard deviation are listed. Data were analyzed by two-way ANOVA. Means were compared by Tukey-Kramer intervals at 0.05 significance level. RESULTS: All surface treatment increased bond strength compared to polished surface and the highest bond strength was found with Palapress resin with etched porcelain surface (8.1 MPa). Bonding agent improved the bond strength of all denture resins to porcelain teeth. Superior bonding was found with Palapress and air-abraded porcelain (39 MPa). CONCLUSION: Resins with different curing methods affect the bond strength of porcelain teeth to denture bases. Superior bonding was found with auto-polymerized resin (Palapress). Application of ceramic primer and bonding agent to porcelain teeth with and without surface treatment will improve the bond strength of all denture resins to porcelain teeth.

NM-23 gene expression and proliferative activity as prognostic indicators in rhabomyosarcoma

To determine nm-23 expression and percentage of Ki-67 labeling index and to correlate these findings with other, rognostic parameters, in rhabdomyosarcoma cases [RMS]. Specimens of 25 cases of rhabdomyosarcoma were studiedfornm-23 antigen immunohistochemically. For evaluation of proliferative activity of tumors, mitotic figures and Ki-67 labeling index were investigated. Ailfindings were analyzed statistically. Fifteen patients were embiyonal rhabdomyosarcoma and ten cases were alveolar rhabdomyosarcoma. Four JMIzents [16%] were stage 1, two [8%] were stage 2, nine [36%] were stage 3 and ten [40%] were stage 4. The percentage of nm-23 positivity was 52%. A significant association was found between nm23 expression and metastasis [p=0.010], where 80% of cases with metastasis at the time of diagnosis showed negative nm-23 expression. On linear regression analysis, Nm-23 expression showed sign[ficant levelfor prediction of metastasis [p=0.042], while initotic figures and Ki-67 labelling index did not reach statistically significant level [p=0.6l9, p=0.062]. These findings suggested that nm-23 expression might be used as a reliable indicator for metastatic potentiality of rhabdomyosarcoma. Further larger prospective studies are neededfor ident ifi cation of other prognostic markers specific for RMS to help us better understand the mechanisms involved in the patho genesis and facilitate the development of novel effective therapies

Nodal status, C-ERBB-2 expression combined with lymphovascular invasion creates a more powerful tool for predicting outcome in breast cancer

To evaluate the prognostic role of peritumoral vascular invasion [PVI] and its association with axillary nodal status and c-erbB-2 expression. Seventy five patients with stage I and II breast carcinoma who underwent conservative breast surgery or modified radical mastectomy were assessed clinically and pathologically for tumor size, grade, axillary lymph node status and peritumoral vascular invasion [PVI]. The immunophenotype of the tumor was determined as: the expression of oestrogen [ER] and progesterone [PgR] receptors, and c-erbB2. Thirty eight patients [50.7%] showed PVI. It was found that extensive PVI was significantly more likely to be associated with nodal positivity, higher tumor grade and c-erbB-2 over-expression. - 52/75 [69.3%] patients showed positive nodal status. The analysis showed that nodal positivity was significantly associated with tumor size, higher grade, presence of PVI and c-erbB-2 overexpression. - PVI and nodal positivity showed no significant association with receptor status. These data suggest that assessment of PVI together with axillary nodal status and c-erbB-2 expression creates a more powerful tool for predicting outcome in patients with breast cancer

Histological And ultrastructural study on the effect of on the submandibular salivary gland and the role of transforming growth factor-alfa [in albine rats]

Tartrazine is a food colouring additive commonly used in Egyptian food industry. This study was done on 15 male albino rats divided into two groups. A control group and a study group. Rats of the study group were given a daily oral dose of tartrazine for 14 weeks. The study was done to investigate the effect of tartrazine on the structure of the submandibular salivary gland, by using light and electron microscopes. The results revealed ill formed vaculated and ruptured salivary acini together with abnormal salivary duct system in serous and mucous acini multicellular demilunes were seen. UItrastructur results showed close faced heterochromatic nuclei surrounded by irregular indistinct, nucleus envelop together with less folding and loss of cellular boundaries mitochondria and rough endoplasmic reticulum were decreased, TGFa activity was weak in the study group compared to their controls. This study recommended to limit the use of colouring food additives and to be used under control

role of pharyngeal repair on acoustic characteristics of tracheoesophageal voice

The tracheoesophageal puncture [TEP] technique for voice restoration is a successful way of providing voice rehabilitation after total laryngectomy. Because postoperative voice quality can vary significantly depending on which type of hypopharyngeal repair is chosen, the aim of this work was to evaluate the effect of these repairs on the TEP voice after total laryngectomy. In this study, the TEP voice was quantitatively and qualitatively evaluated in 20 patients using Provox 2 A registerd prosthesIs after standard total laryngectomy. The patients were divided according to the type hypopharyngeal repair into four groups [five cases for each]; A: pharyngoesophageal myotomy, B: pharyngeal plexus neurectomy, C: non-muscle repair, and D: transverse repair. The groups were compared with each other for different voice parameters. The acoustic results of the four pharyngeal repair groups did not reveal significant difference for most of the voice parameters. Primary TEP voice restoration is recommended as it offers several advantages; 1. I simple, effective and not time consuming, 2. It is a low morbidity procedure, 3. It is cost effective as it eliminates a secondary procedure for voice restoration and reduces prolonged speech therapy sessions, 4. Early voice production gives the patient a psychological boost which improves convalescence. All used methods of pharyngeal repair succeeded to prevent postoperative neopharyngeal spasm

Water sorption and solubility of different acrylic denture base resins processed by injection molding technique and cured with different curing methods

Statement of problem: Because water sorption of acrylic resins is accompanied by volumetric change, it is a physical property of importance. As a residual monomer leaches into the oral fluids causes tissue irritation, low solubility of these resins is desired

Purpose: This study was made to compare the water sorption and solubility of four different types of acrylic resins using injection molding technique in comparison with heat cured acrylic resin using compression molding technique

Results: All injection processed resins exhibited less water sorption than the compression processed resin [control group]. No significant difference was noted in the water sorption of all injection processed resins. Microwave polymerized acrylic resin [Acron MC] showed significant increase in the solubility value than the other tested acrylic denture base resins