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Biomedical subjects

W Scherer

Publications and source records attributed to W Scherer.

At least 55 records · Page 3Linked to original sources
PubMed1990

Comparison of microleakage between direct placement technics and direct inlay technics.

Laboratory studies have indicated that improvements in the physical properties of composite restorations, especially for posterior teeth, may be obtained if these materials underwent heat treatment prior to insertion. The purpose of this study was to compare the microleakage in Class II restorations ending on cementum/dentine when these preparations were restored by a direct placement composite resin as opposed to a direct inlay composite resin. Thirty-six human posterior mandibular teeth were used in this study and randomly divided into three equal groups; Group I was prepared and restored with the composite Ful-fil in a direct placement technique. Groups II and III were prepared and restored using a direct composite resin inlay technique. The material used in Group II was Brillant D.I.; that of Group III, Ful-ful. All preparations terminated 1.0 mm apical to the CEJ. The composite resin patterns of Groups II and III were oven-tempered before cementing with D.I. Duo Cement. Specimens were thermocycled 125 times between 5-55 C. Microleakage was noted cervically on a scale of 0 to 5. The composite Ful-fil, used as a direct placement material, exhibited less leakage (P less than 0.05) than either the Brillant D.I. composite or Ful-fil composite when these materials were placed as direct composite inlays.

Bicuspid↗
PubMed1989

Clinical features and management of amebic liver abscess. Experience from 29 patients.

29 patients with amebic liver abscess were evaluated in a study to examine clinical picture, laboratory data, epidemiology, radiologic methods, and therapy. Since the clinical picture was unspecific a considerable amount of misdiagnoses occurred, and often originated from pulmonary symptoms. To establish diagnosis one should rely on the triad with positive amebic serology, intrahepatic scanning defects, and clinical picture with fever, right upper quadrant pain, and hepatomegaly. Nearly all patients had an exposure history of travel or immigration from endemic areas in the tropics. Medical therapy with metronidazole alone is highly effective and leads to defervescence and clinical improvement usually within 3-5 days. Invasive procedures, such as needle aspiration or surgical drainage of the abscess are rarely needed; these invasive methods neither shorten the course of the disease nor improve prognosis.

Adult↗
PubMed1989

Microleakage of three glass ionomer cement bases.

This study compared the marginal leakage in Class V restorations using three different GIC bases and a composite resin sandwich. The specimens were randomly divided into three equal groups, and the following GIC materials were used as bases: Group I: Ketac-Bond Aplicap; Group II: GC Dentin Cement; Group III: Shofu GlasIonomer Base. The results indicated less microleakage in restorations with a Shofu GlasIonomer Base while no statistical differences were noted between Ketac-Bond Aplicap and GC Dentin Cement.

Dental Cements↗
PubMed1989

Antimicrobial properties of glass-ionomer cements and other restorative materials.

The antimicrobial properties of 14 different restorative materials, nine of which were glass-ionomer cements, were compared and observed in this study. The materials were mixed according to manufacturers' specifications and exposed to four types of bacteria commonly found in caries and plaque. Zones of bacterial inhibition were measured for all materials in millimeters. Glass-ionomer cement materials, materials containing zinc oxide, and amalgam produced measureable zones of inhibition.

Bacteria↗
PubMed1989

Evaluation of the ability of glass-ionomer cement to bond to glass-ionomer cement.

This study investigated the cohesive bond strengths of glass-ionomer cement at three setting and etching intervals and compared these bonds to the shear strength of the material itself. Bonded cylinders were created and then sheared using the Instron Universal Testing Machine. Analysis of bond values of glass ionomer added to glass ionomer indicate bond variability and low cohesive bond strength of the material. Bond values of unbonded glass-ionomer material indicate that the material itself is stronger than bonds established between bonded samples.

Dental Bonding↗
PubMed1989

Microleakage of capsulated glass ionomer cements.

The purpose of this study was to compare marginal leakage in Class V preparations restored and finished within 20 minutes with two different capsulated and syringeable restorative glass ionomer cements. The materials were inserted and finished following manufacturer's specifications. Specimens were thermocycled 125x in fuchsin dye at 5 degrees C and 55 degrees C, mounted in acrylic and sectioned faciolingually. Microleakage was observed and rated on a scale of 0 to 3 at both enamel and cervical margins. The results of this study indicate that: 1) both materials exhibit marginal leakage at enamel and cervical margins, 2) no significant difference in microleakage was found between these materials, and 3) enamel margins leaked less than cementum/dentin margins with each material.

Dental Bonding↗
PubMedDate not supplied

Antimicrobial properties of VLC liners.

The antimicrobial activity of several visible light cured glass ionomer and liner materials against three bacteria commonly found in the oral cavity is discussed. Vitrabond light cure glass ionomer produced zones of inhibition against all the bacteria tested in this study. It appeared to resemble a true glass ionomer cement in regard to its antimicrobial properties whereas the other materials used in this study appeared to possess no antimicrobial activity.

Actinomyces↗
PubMedDate not supplied

Third generation dentin bonding agents: a microleakage study.

This article examines and compares the extent of microleakage after 24 hours in freshly extracted teeth using three newer or "third generation" dentin bonding agents. Gluma/Pekalux and Scotchbond 2/Silux were more effective in preventing microleakage in cementum/dentin margins than was Universal Bond/Prisma Micro-fine.

Adhesives↗
PubMedDate not supplied

Antimicrobial properties of dental dentin-enamel adhesives.

This study evaluated the antimicrobial activity of Universal Bond II adhesive and two experimental versions of Universal Bond II adhesives against the bacteria, Streptococcus mutans. The zones of bacterial inhibition produced by three samples of the adhesive (identified as Batches 1, 2, and 3) were measured and compared. Batch 1 contained 0.7% glutaraldehyde, Batch 2 contained 1.0% glutaraldehyde, and Batch 3 contained 0.45% glutaraldehyde (current Universal Bond II adhesive). The bacteria was swabbed over the surface of agar plates in two directions. The plates were divided into the following two groups: Group I-Batches 1, 2, 3 were placed into wells for 1 minute before being cured. Group II-Batches 1, 2, 3 were placed into wells for 20 seconds before being cured. Zones of microbial inhibition were measured in millimeters at the end of 24, 48, and 72 hours. All batches of the adhesive produced zones of inhibition against S. mutans. All batches of the adhesive maintained zones of inhibition throughout the 72 hours of the study.

Adhesives↗
PubMedDate not supplied

An all porcelain lingual bonded retainer: a case study.

In recent years, resin bonded metal retainers have been used to replace teeth in a conservative manner. In addition, porcelain laminates or veneers have been used in esthetic dentistry on single teeth in areas that previously dictated reductions of tooth structure. This paper describes a method of replacing a missing lower anterior tooth with an all porcelain bonded retainer.

Dental Bonding↗
PubMedDate not supplied

Clinical technique for an in-office porcelain modification.

All porcelain restorations, especially intra- and extracoronal restorations, have become an accepted treatment modality for the esthetic restoration of posterior teeth. One problem with these restorations is the limited ability to modify the porcelain when a proximal contact is not present or there is an open margin. Using a low-fusing porcelain in a glazing oven, practitioners can easily accomplish such modifications during the try-in and cementation appointment for porcelain inlays. This technique eliminates the need for returning the porcelain inlay to the laboratory for modification and a second patient visit to complete the restoration. This paper describes an in-office procedure for modifying porcelain restorations and a scanning electron micrographic evaluation of the etched porcelain surface after using this modification technique.

Acid Etching, Dental↗
PubMedDate not supplied

At-home bleaching system: effects on enamel and cementum.

An analysis by scanning electron microscopy was undertaken to investigate the effects of bleaching on enamel-cementum surface morphology. Teeth were investigated in five groups: control; vital bleached for 5, 15, and 30 days; and 37 percent phosphoric acid gel etched for 20 seconds. Only the gel-etched group exhibited etching patterns. Shade change in vital bleached teeth was noted in the group vital bleached for 30 days.

Dental Cementum↗