Solubility of dental core build-up materials in electric fields.

Background/purpose: Over 250 years has been researched over the consequences of oral galvanism. Previous studies have already examined the influence on dental fixation materials. The aim of this study was to investigate the electro-chemical solubility behavior of different dental core build-up materials in a pseudo-realistic galvanic experimental setup.

Loss of Aβ-nerve endings associated with the Merkel cell-neurite complex in the lesional oral mucosa epithelium of lichen planus and hyperkeratosis.

The Merkel cell-neurite complex initiates the perception of touch and mediates Aβ slowly adapting type I responses. Lichen planus is a chronic inflammatory autoimmune disease with T-cell-mediated inflammation, whereas hyperkeratosis is characterized with or without epithelial dysplasia in the oral mucosa. To determine the effects of lichen planus and hyperkeratosis on the Merkel cell-neurite complex, healthy oral mucosal epithelium and lesional oral mucosal epithelium of lichen planus and hyperkeratosis patients were stained by immunohistochemistry (the avidin-biotin-peroxidase complex and double immunofluorescence methods) using pan cytokeratin, cytokeratin 20 (K20, a Merkel cell marker), and neurofilament 200 (NF200, a myelinated Aβ- and Aδ-nerve fibre marker) antibodies.

The growth of Staphylococcus aureus and Escherichia coli in low-direct current electric fields.

Electrical potentials up to 800 mV can be observed between different metallic dental restorations. These potentials produce fields in the mouth that may interfere with microbial communities. The present study focuses on the impact of different electric field strengths (EFS) on the growth of Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922) in vitro.

Induction of apoptosis and up-regulation of cellular proliferation in oral leukoplakia cell lines inside electric field.

Objective: In dentistry, metallic alloys are used for dentures, restorative materials, and orthodontic devices. Electric voltages up to 950 mV may occur between different dental alloys in the oral cavity. This study aimed to investigate physiologic reactions of oral leukoplakia cells in vitro to electric fields.

Indirect sinus floor elevation for osseointegrated prostheses. A 10-year prospective study.

The aim of this study was to evaluate the indirect/closed maxillary floor elevation technique for the insertion of osseointegrated implants to support fixed prostheses clinically. Thirty-one patients (19 female, 12 male) with a mean age of 62 +/- 9 years were selected for this study. All patients needed implants in the posterior maxillary region to support osseointegrated prosthesis.

Direct current electrical fields induce apoptosis in oral mucosa cancer cells by NADPH oxidase-derived reactive oxygen species.

The presence of more than one dental alloy in the oral cavity often causes pathological galvanic currents and voltage resulting in superficial erosions of the oral mucosa and eventually in the emergence of oral cancer. In the present study the mechanisms of apoptosis of oral mucosa cancer cells in response to electromagnetic fields was investigated. Direct current (DC) electrical fields with field strengths between 2 and 16 V/m, applied for 24 h to UM-SCC-14-C oral mucosa cancer cells, dose-dependently resulted in decreased cell proliferation as evaluated by Ki-67 immunohistochemistry and upregulation of the cyclin-dependent kinase (CDK) inhibitors p21(cip1/waf1) and p27(kip1), which are associated with cell cycle arrest.

Regulation of the multidrug resistance transporter P-glycoprotein in multicellular prostate tumor spheroids by hyperthermia and reactive oxygen species.

Hyperthermia is an important component of many cancer treatment protocols. In our study the regulation of the multidrug resistance (MDR) transporter P-glycoprotein by hyperthermia was studied in multicellular prostate tumor spheroids. Hyperthermia treatment of small (50-100 microm) tumor spheroids significantly increased P-glycoprotein and mdr-1 mRNA expression with a maximum effect at 42 degrees C, whereas only moderate elevation of P-glycoprotein was found in large (350-450 microm) tumor spheroids.

Effect of laboratory procedures and thermocycling on the shear bond strength of resin-metal bonding systems.

Statement Of Problem: During fabrication or repair of removable partial dentures, resin-to-metal or resin-to-denture tooth bonds may be stressed by laboratory procedures.

Purpose: The purpose of this in vitro study was to evaluate the effect of steam cleaning, boiling, ultrasonic cleaning (laboratory procedures), and thermocycling on shear bond strength of resin bonds to metal and denture teeth.

Material And Methods: Resin-metal bonding systems and their specific veneer resins (Rocatec, Sinfony; Rocatec, Visio-Gem, HLC-BOND, Zeta LC and Ducera experimental veneer resin) were tested on a Co-Cr alloy (Wirobond C).

Pulmonary risk of intraoral surface conditioning using crystalline silica.

Purpose: This study evaluated the pulmonary risk caused by possible respirable dust of Al2O3 and SiO(x) resulting from chairside tribochemical sandblasting procedures in a dental office.

Materials And Methods: Dust was collected using a trap near the working field, and quantitative morphologic determination and identification were performed with SEM and EDAX. Forty blasting processes (total time 20 minutes) were aimed at a dummy to obtain maximum pollution of the workplace.

Clinical study on the reasons for and location of failures of metal-ceramic restorations and survival of repairs.

Purpose: A recently introduced technique, the Cojet system, using SiOx (Al2O3 coated with silisic acid), provides ultrafine mechanical retention by sandblasting, as well as a chemicophysical bond between the metal-ceramic and the composite resin. This study determined the reasons for and locations of failures of metal-ceramic restorations and evaluated the survival of the intraoral silica-coating system used for the repair of failed restorations.

Materials And Methods: A total of 153 patients possessing 289 fractured crowns were involved in this study; 255 of these fractures were on fixed partial dentures, whereas 34 were on single crowns.

Articulator-related registration--a simple concept for minimizing eccentric occlusal errors in the articulator.

Purpose: The purpose of this study was to develop an easy-to-use procedure for individual registration and to test its accuracy. Unlike common principles, the method should be based on a transfer of the articulator geometry to the patient.

Materials And Methods: The system consists of an articulator holding a bite plate in a standard position.