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Biomedical subjects

W F Caughman

Publications and source records attributed to W F Caughman.

At least 37 records · Page 2Linked to original sources
PubMed1991

The curing potential of light-activated composite resin luting agents.

This study determined the effect of different light exposure times on the polymerization of three composite resins used as cements (Heliosit, Visio-Fil, and Dual) through various thicknesses and shades of two preprocessed composite resins (Isosit and Visio-Gem). The Knoop hardness of the surface of the luting resin was measured after polymerization and selected samples were remeasured at 24 hours to evaluate continued cure. Results indicated that polymerization of light-activated composite resin luting agents cannot predictably be accomplished through a restoration exceeding 2 mm in thickness using a light exposure of 90 seconds or less. The combined chemical and light-activated cure of Dual cement recorded the highest percentage of acceptable hardness values.

Acrylic Resins↗
PubMed1991

Correlation of cytotoxicity, filler loading and curing time of dental composites.

Previous studies have shown that dental resin composites tested in cell culture produce cytotoxic effects on human gingival tissues. In this study, the cytotoxic potential of resin composites on primary human gingival fibroblast cultures was evaluated, based on inhibition of cellular protein synthesis measured by [35S] methionine incorporation. Both resin content and percentage of monomer conversion were considered as potential causes of cytotoxicity. Three resin composites were selected to provide a range of filler content from 45 to 86 wt%. Duplicate sample discs (1 mm thick x 10 mm diameter) of each composite were polymerized for 15, 30 and 60 s, followed by heat (110 degrees C, 10 min), and the degree of monomer conversion for each sample group was measured using Fourier transform infrared spectrophotometry. Identically fabricated discs were placed into 35 mm culture dishes with gingival fibroblasts and incubated for 24 h at 37 degrees C. The cell monolayers then were labelled at 24 h with [35S] methionine, washed and solubilized; then incorporated radioactivity was quantitated by liquid scintillation spectrometry. For each composite, as the percentage of monomer conversion increased, cellular toxicity decreased. In comparing different composites having similar monomer conversions, it was found that the filler/resin ratio was not the only factor determining the composite's relative toxicity.

Biocompatible Materials↗
PubMed1991

Spatial realignment using the hybrid resin-bonded bridge.

As an alternative to a conventional fixed partial denture, a modification of the hybrid resin-bonded bridge was used to compensate for a spatial discrepancy accentuated by a missing tooth. The proximal margins of the restoration were extended onto the facial surfaces of the abutment teeth to create a partially veneered surface. The abutment teeth were widened by shifting the embrasure into the edentulous space, thus creating more esthetic proportions.

Cementation↗
PubMed1990

When a patient with a bleeding disorder needs dental work. How you can work with the dentist to prevent a crisis.

Patients with bleeding disorders need close cooperation between their physician and their dental practitioner to receive safe, comprehensive dental care. When indicated, physicians must advise a compromised treatment plan to avoid deep injections or surgical procedures that may initiate a bleeding crisis in patients at risk. The conditions most commonly seen that require special consideration are long-term use of antithrombotic agents, platelet dysfunction caused by chronic renal failure, and congenital clotting factor deficiencies. Even these patients may undergo a high-risk procedure, such as periodontal surgery, with adequate precautions and preparation.

Blood Coagulation Disorders↗
PubMed1990

Glass ionomer and composite resin cements: effects on oral cells.

Because the cement interfaces of restorations can approximate the periodontium, it is critical to determine the biocompatibility of cements. In this study, the cytotoxic potential of resin luting agents on cultures of gingival fibroblasts and oral epithelial cells was evaluated for direct microscopic cytotoxicity, cell morbidity, impaired adherence, and inhibition of macromolecular synthesis. Visible effects ranged from severe toxicity with inadequately polymerized composite resin to no detectable morphologic cell damage by a glass ionomer cement, but inhibition of protein and RNA synthesis varied with the material and cell type. The glass ionomer cement demonstrated no morphologic damage, but exhibited inhibition of macromolecular synthesis in gingival fibroblasts. These results confirmed that in vitro metabolic assays are appropriate for examining the biologic effects of materials.

Cells, Cultured↗
PubMed1989

Oral trauma. Emergency care of lacerations, fractures, and burns.

Emergency physicians are usually the first to see patients with injuries to oral and facial tissues. Because many of these patients may have life-threatening neurologic injuries, secondary oral and perioral problems may be overlooked initially. These injuries, however, have a profound potential for causing lifelong disability and disfigurement and should be addressed as soon as the patient's condition stabilizes. It is essential to diagnose and manage these problems effectively in the emergency setting and then to make prompt direct referral to an appropriate specialist when the patient's condition permits.

Burns, Electric↗
PubMed1989

Disinfection of visible-light-curing devices.

Assays were developed for evaluating disinfection of visible-light-curing devices which were deliberately contaminated with an indicator organism, Streptococcus mutans, and devices which were contaminated during routine clinical use. Results indicated that wiping the surface with a substituted phenolic agent followed by wrapping in gauze saturated with the same solution was most effective for disinfecting the device handle and tip surfaces. Longer contact with the disinfectant is recommended to ensure virucidal/sporicidal action.

Dental Equipment↗
PubMed1987

A double-mix cementation for improved esthetics of resin-bonded prostheses.

An efficient technique is described for reducing incisal discoloration of abutment teeth without creating a cement line. One disadvantage is the need for both opaque and tooth-colored translucent resin cements, but the complex procedure can be facilitated by increasing the working time of the resin cements.

Cementation↗
PubMed1987

Combining resin-bonded prostheses and removable partial dentures: report of case.

The resin-bonded prosthesis provides an alternative for tooth replacement in that the prosthesis can be combined with other dentures. The prosthesis was used conservatively in this case, with modified abutment teeth to improve the function of the removable partial denture. Decreased expense, shorter chair time, and the noninvasive nature of the procedure make the prosthesis an option for patients with special problems.

Acid Etching, Dental↗