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Biomedical subjects

W Scherer

Publications and source records attributed to W Scherer.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

Addition of fresh amalgam to existing amalgam: microleakage study.

The purpose of this in vitro study was to determine whether adhesive lining materials reduce microleakage in amalgam restorations, and to observe the degree of microleakage at the interface between freshly placed (new) and existing (old) amalgam. Forty-eight specimens were used in the experimental groups. The materials used to study microleakage in this investigation were: copal varnish, a dentin bonding agent (Clearfil New Bond), and a 4-META adhesive (Amalgambond). No significant difference in microleakage was found at the interfaces between freshly placed and existing amalgam. Significantly less microleakage was noted in specimens using the 4-META adhesive and the dentin bonding agent as compared to specimens in which no lining material was placed. Significantly less microleakage was noted in specimens using the 4-META adhesive compared to specimens using cavity varnish.

Analysis of Variance↗
PubMedDate not supplied

Bonding fresh amalgam to existing amalgam: a shear and flexural strength study.

The purpose of this study was to compare the shear and flexural strength obtained when various adhesives or liners were used to bond freshly placed amalgam to existing amalgam. The adhesives used in this study were the following: cavity varnish, 4-META adhesive (Amalgambond), and a dentin bonding agent (Clearfil New Bond). After samples were fabricated, shear bond strengths were determined by using an Instron Testing Machine, and flexural strengths determined using a Material Test System (MTS) testing machine. All test groups produced shear and flexural strengths less than one half of the control group. The dentin bonding agent and the 4-META adhesive produced significantly higher shear and flexural strengths than the test group in which no lining material was used.

Analysis of Variance↗
PubMedDate not supplied

Addition of fresh amalgam to existing amalgam utilizing various adhesive liners: a SEM study.

The purpose of this study was to observe the interfaces between (1) dentin and amalgam and (2) freshly placed amalgam and existing amalgam using various adhesive liners. Specimens were randomly assigned to four equal groups for liner placement: Group I--control, no liner used; Group II--copal varnish; Group III--4-META adhesive; Group IV--dentin bonding agent. After liner placement and amalgam replacement, specimens set for 24 hours and were then thermocycled in 0.5% basic Fuchsin dye, sectioned, and SEM analyses performed. Microgaps appeared in a disjointed fashion at the interface between freshly placed and existing amalgam. The 4-META adhesive appeared to establish a bond between amalgam and tooth structure and, thus, diminished the microgap between amalgam and dentin.

Composite Resins↗
PubMedDate not supplied

Vital bleaching agents and oral antiseptic: effect on anaerobic bacteria.

This in vitro study compared the antimicrobial effect of several at-home bleaching agents and an oral antiseptic against anaerobic bacteria that are commonly found in the oral cavity. Zones of inhibition produced by Rembrandt Lighten Bleaching Gel, Opalescence, and Peroxyl were measured and compared. All the materials produced zones of inhibition with the five bacteria used in the study.

Bacteroides↗
PubMedDate not supplied

At-home bleaching system: effect on gingival tissue.

This study evaluated the effects of an at-home vital bleaching system on gingival responses over a 6-week period. Objective measures were utilized to measure and monitor gingival inflammation over this period of time. Vital bleaching was performed as follows: (1) bleaching gel in a prefabricated mouthguard and (2) an ad-mix technique--bleaching gel and toothpaste in a 1:1 ratio. In addition a control group used a placebo in a prefabricated mouthguard. The at-home vital bleaching system produced no adverse gingival tissue responses. Furthermore, the at-home vital bleaching system helped produce a therapeutic effect on inflamed gingival tissues over the course of the study.

Adult↗
PubMedDate not supplied

Effects of pH on the dentin surface.

A microleakage and scanning electron microscope (SEM) study was conducted in order to investigate the effects of acidic primers on prepared dentin surfaces. The microleakage study revealed that no significant differences were noted between the five materials tested in regard to leakage at enamel and dentin margins. SEM analyses revealed that the smear layers of all specimens were altered in some manner. Further long-term clinical studies should be conducted to evaluate acidic treatment of dentin.

Composite Resins↗
PubMedDate not supplied

Bonding amalgam to tooth structure: a scanning electron microscope study.

The purpose of this scanning electron microscope study was to observe the interface between dentin and amalgam utilizing various adhesive resin cements. The adhesive resin materials used in this study were Imperva Dual, Geristore, and Panavia. The scanning electron micrographs revealed that bonds were established between amalgam, adhesive resins, and dentin.

Dental Amalgam↗
PubMedDate not supplied

Mucous membrane pemphigoid: a disease of the elderly.

Mucous membrane pemphigoid (MMP) is a vesiculo-bullous, mucocutaneous disease that generally affects elderly people. The diagnosis of mucous membrane pemphigoid may be overlooked since the disease is often confined to the mouth and desquamative gingivitis may be the only symptom. Gerodontic patients with this condition are often diagnosed as having "desquamative gingivitis" without obtaining the proper therapy to control chronic pain and effect disease remission. The discomfort associated with eating may prevent many elderly patients from obtaining adequate nutrition. Topical and/or systemic corticosteroid therapy are the only available methods of managing this condition. Immunologic studies support the autoimmune nature of MMP and infer that it may be a variant of bullous pemphigoid.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Effects of TRIS and HEPES on function of rabbit muscle light sarcoplasmic reticulum.

ATP hydrolysis activity and calcium transport activity were determined on light sarcoplasmic reticulum from rabbit skeletal muscle. The effects of two buffers, TRIS and HEPES, were compared. Titration of TRIS into sarcoplasmic reticulum preparations in HEPES provided evidence for TRIS inhibition of ATPase activity and TRIS stimulation of calcium transport activity.

Adenosine Triphosphate↗
PubMedDate not supplied

Antimicrobial activity of cavity disinfectants.

The purpose of this study was to determine the antimicrobial activity of four commercially available cavity disinfectants and one prescription mouthwash as they came into contact with bacteria commonly found in the oral cavity. Streptococcus mutans, salivarius, and Actinomyces viscosus were used in the study. Zones of microbial inhibition were measured in millimeters after 48 hours. The results of this study indicate that all of the antimicrobial agents demonstrated activity against the bacteria tested. Consepsis Solution produced the largest zones of inhibition against all three of the bacteria used.

Acid Etching, Dental↗
PubMedDate not supplied

Treating enamel surfaces with a prepared pumice prophy paste prior to bonding.

The use of pumice to remove the salivary pellicle, plaque, and/or surface debris is a well-known procedure. However, pumice can act as a contaminant. Therefore, a slurry of pumice without additives is recommended for use prior to bonding procedures. This article presents a review of the shear bond strengths obtained by bonding composite resin to enamel after the enamel had been cleansed with a slurry of pumice and a premixed caplet of pumice.

Analysis of Variance↗
PubMedDate not supplied

Evaluations of the interface between amalgam and dentin with a single component dentin bonding system.

The purpose of this scanning electron microscope study was to observe the dentin-amalgam interface after utilizing a standard restorative liner and a single-component dentin adhesive. Continuous interface gaps of over 15 mu were observed in specimens containing no lining and Copal varnish. Discontinuous 5 microns gaps were observed in specimens treated with PQ1. Additionally, specimens treated with PQ1 exhibited resin interpenetration into the dentin surfaces.

Adhesives↗
PubMedDate not supplied

The antimicrobial properties of a urea-based handwash lotion with triclosan.

The purpose of this study was to determine and compare the antimicrobial action of a urea-based handwash lotion with triclosan with a lipid-depleting detergent-based handwash product with 4% chlorhexidine gluconate. The zones of inhibition produced by the two handwash lotions and the one produced by the positive control were similar against all strains of bacteria tested, indicating that a urea-based handwash lotion with triclosan is as effective as a lipid-depleting handwash lotion in inhibiting bacterial activity.

Actinomyces viscosus↗
PubMedDate not supplied

Sensitivity study in vivo: glass-ionomer versus zinc-phosphate bases beneath amalgam restorations.

This study in vivo evaluated the sensitivity of class 1 and 2 amalgam restorations which had bases of either zinc phosphate or an admix, silver-reinforced glass ionomer. The evaluation of sensitivity was done by providing the patient with five postcard questionnaires to be mailed to the clinic over a period of time from one to 28 days. Teeth restored with amalgam and silver-reinforced glass ionomer were significantly less sensitive to cold than those restored with amalgam and zinc phosphate.

Dental Amalgam↗
PubMedDate not supplied

Anodontia of the permanent dentition: fourteen years after initial diagnosis.

The congenital absence of teeth, total anodontia, may involve both the primary and permanent dentitions. This paper updates the dental history of a twenty-eight-year-old Greek-American woman first reported in 1977 by Herman and Moss, when she was fourteen. Five complete sets of dentures had been made for her in thirteen years. Treatment was more complex due to an underdeveloped maxilla and a prognathic mandible.

Adult↗