Biomedical subjects

A V Ritter

Publications and source records attributed to A V Ritter.

29 records · Page 2Linked to original sources

PubMed1999

A clinical, radiographic, and scanning electron microscopic evaluation of adhesive restorations on carious dentin in primary teeth.

OBJECTIVE: The purpose of this project was to evaluate the performance of a dentin adhesive system on carious and noncarious primary dentin in vivo. METHOD AND MATERIALS: Forty-eight primary molars with carious lesions were randomly assigned to 2 different treatments: group 1 (control, n = 24)--All identifiable, irreversibly infected dentin was removed prior to the application of the bonding agent and restorative material; group 2 (experimental, n = 24)--Irreversibly infected dentin was partially removed prior to the application of the bonding agent and restorative material. The control and experimental teeth were clinically monitored every 3 months and evaluated 12 months after restoration. The teeth were extracted around the time of exfoliation and processed for scanning electron microscopy. RESULTS: Retention rate, marginal integrity, and pulpal symptoms were identical in both groups. Radiographically, the radiolucent area associated with the experimental restorations did not increase with time in 75% of the cases. For the control group, the adhesive system formed a hybrid layer. In the experimental group, there was morphologic evidence of the formation of an acid-resistant "altered hybrid layer." An acid-resistant tissue, resulting from the interdiffusion of adhesive resin within the area of carious dentin, was observed adjacent to and under the altered hybrid layer. CONCLUSION: Application of an adhesive restorative system to irreversibly infected dentin did not affect the clinical performance of the restoration.

Child↗

PubMed1998

Direct posterior composite resin restorations: current concepts for the technique.

Due to the development of sound clinical procedures and evolution of advanced restorative materials, composite resins are being used with increasing frequency for direct posterior applications. When the clinical protocol for the use of composite resin is performed properly, this material can be utilized with success and predictability. This article presents the advantages and limitations of this restorative modality. It also reviews the characteristics of contemporary composite resin materials and demonstrates the treatment protocol that is utilized to achieve aesthetic restorations in the posterior segment.

Acid Etching, Dental↗

PubMed1998

The use of liners under amalgam restorations: an in vitro study on marginal leakage.

OBJECTIVE: Marginal leakage of amalgam restorations may lead to secondary caries and pulpal damage. The purpose of this study was to determine the effect various cavity liners might have on microleakage. METHOD AND MATERIALS: Mesio-occlusodistal amalgam restorations with margins on enamel and dentin were treated with different liner materials (an adhesive system, a topical fluoride gel, a cavity varnish, and a glass-ionomer cement) in vitro. Following restoration, the teeth were submitted to thermocycling in a stained solution and sectioned to allow assessment of microleakage. RESULTS: On enamel, the control group (no liner) and the glass-ionomer-lined group had equivalent leakage scores and were superior to every other group. On dentin, only the glass-ionomer specimens had superior performance. The cavity varnish and fluoride-lined specimens exhibited the highest leakage scores. CONCLUSION: The use of liners does not reduce microleakage on amalgam restorations when the cavity margins remain on enamel. On dentin margins, a glass-ionomer liner can reduce microleakage.

Adhesives↗

PubMed1996

Posterior resin composite restorations: a new technique.

A new technique for the performance of resin composite direct restorations on posterior teeth is presented. A clear acrylic resin matrix, fabricated prior to the preparation of the occlusal and proximal surfaces, is employed. The matrix allows the fast and accurate reproduction of the anatomic details from the original occlusal surface of the tooth, as well as the marginal ridges in the case of Class II (occlusoproximal) restorations. Advantages and limitations of the procedure are discussed.

Acrylic Resins↗

PubMed1996

Influence of finishing and polishing procedures on the decision to replace old amalgam restorations: an in vitro study.

The purpose of this study was to establish the influence that finishing and polishing of existing amalgam restorations might have on the decision to replace them. Forty extracted teeth, in which amalgam restorations had been placed in vivo, were individually examined by 60 practitioners and students prior to and following standard finishing and polishing procedures. Examiners, who had not been informed of the study's methodology or objective, opted either for maintaining or replacing the restoration in question. The main reasons for replacement were also registered. Finishing and polishing significantly reduced the number of decisions to replace restorations in all groups and for all practitioners. "Appearance" (anatomic shape) was the most frequently cited reason for replacing restorations before finishing and polishing, followed by marginal defects and secondary caries.

Dental Amalgam↗

PubMed1995

Nonvital tooth bleaching: guidelines for the clinician.

The combination of intracoronal and extracoronal bleaching represents a conservative treatment to restore esthetics to darkened or stained nonvital teeth. Notwithstanding the eventual risks and difficulties accompanying such technique, nonvital teeth often can be successfully lightened. This article presents a few guidelines for bleaching nonvital teeth as well as a clinical case to illustrate the indications and clinical protocol for the technique.

Clinical Protocols↗

PubMed1994

Adhesive restorations with amalgam: guidelines for the clinician.

The adhesive amalgam restoration technique combines the good properties of amalgam with the principles of tooth structure preservation and marginal seal inherent to adhesive materials. In spite of lack of longitudinal data, results of early clinical and laboratory tests are encouraging. If the present research is substantiated by clinical confirmation of their results, bonded amalgam restorations will become routine. The purpose of this article is to present a brief literature review on adhesive amalgam restoration and to introduce guidelines for its use.

Dental Amalgam↗

PubMedDate not supplied

Teaching of posterior resin-based composite restorations in Brazilian dental schools.

OBJECTIVE: The purpose of this study was to evaluate the teaching program of Class I and Class II resin-based composite (RBC) restorations in Brazilian dental schools and to observe if any differences were found from similar surveys conducted in North American, European, and Japanese dental schools. METHOD AND MATERIALS: A questionnaire containing 15 questions was distributed to 92 Brazilian dental schools, and 64 (70%) schools returned the questionnaire. The questions inquired the amount of time the curriculum dedicated to teaching of posterior RBC restorations, future expectation regarding the teaching time, limitation in extension of the occlusal width and the proximal box in Class II, contraindications for placing posterior RBC restorations, protocol for using bases and liners, brand of bonding agents and RBC used, instruments and techniques employed for finishing, cost relative to amalgam restorations, and biologic reactions related to the use of posterior RBC. The responses were calculated as percentages based on the number of schools that responded to the questionnaire. Where appropriate, the Chi-squared test and the Fisher exact test were used for statistical analysis. RESULTS: Of the dental schools that responded, 88% dedicated 10% to 50% of the teaching time in operative dentistry to posterior RBC restorations. A significant correlation (P = 0.041) was found between the percentage of time dedicated to the teaching of posterior RBC restorations and the higher cost of posterior RBC compared to amalgam restorations. Resin-based composite restorations cost 30% to 70% more than amalgam restorations in the 40% of dental schools that charged a fee. Posterior composites for large restorations in molars were used by 14% of the dental schools. Base and liner were not placed by 10% of dental schools in deep Class I or Class II RBC restorations. One school did not recommend acid etching of the dentin. CONCLUSION: No major differences were found in the teaching philosophy of posterior RBC restorations by comparing the Brazilian data to the data from similar surveys done in North America, Japan, and Europe.

Acid Etching, Dental↗

PubMedDate not supplied

Does clinical experience affect occlusal caries diagnosis and sealant recommendation? An in vitro study.

The purpose of this in vitro study was to evaluate the effect of the length of clinical experience on clinician's diagnosing caries and recommending sealants on the occlusal surfaces of permanent/caries free third molars. The third molars involved in this study had been extracted prior to eruption. There were three study groups: dental students, clinicians with five to ten years experience, and clinicians with fifteen to twenty years of practice. Twenty-four percent of the entire sample diagnosed caries. Clinicians with five to ten years of practice diagnosed occlusal caries significantly more than clinicians with fifteen to twenty years of practice, but not significantly differently than senior dental students. Clinicians recommended sealants significantly more than dental students. The most frequent reason for sealant indication was prevention. The results indicate that clinical experience alone does not impart better caries diagnosis and sealant recommendation criteria.

Attitude of Health Personnel↗

PubMedDate not supplied

Tooth fragment reattachment: an alternative for restoration of fractured anterior teeth.

The development of advanced adhesive systems has made it possible to bond various substrates, e.g., composite resin and vital or nonvital tooth structures. The management of coronal and coronoradicular fractures in the maxillary region with these adhesive materials is easier, safer, and more efficacious than the use of traditional treatment alternatives that involve the use of posts and cores and/or other mechanical devices to obtain retention. Ability to bond the dislocated segment of the fractured tooth constitutes a significant step forward in the management of this clinical condition.

Adolescent↗

PubMedDate not supplied

An in vitro study of the effect of restorative technique on marginal leakage in posterior composites.

The purpose of this in vitro study was to compare marginal leakage of class 2 light-cured composite resin restorations, with different insertion and polymerization techniques. Fifty sound premolars extracted for prosthetic purposes were used in the study. Conservative class 2 (MOD) preparations were made in all teeth, with one proximogingival margin on enamel and the other on cementum. All the preparations and restorations were performed by the same operator utilizing the same restorative materials. After restoration the teeth were thermocycled and their gingival margins exposed to a dye. Results showed that the kind of matrix system had no significant influence upon the degree of marginal leakage on enamel. On cementum, oblique and horizontal incremental insertion and polymerization techniques using the collimator cone exhibited the least leakage, while the clear matrix band/reflective wedge technique presented the greatest leakage.

Bicuspid↗