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.

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.

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.

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.

Influence of acid type (phosphoric or maleic) on the retention of pit and fissure sealant: an in vivo study.

Two hundred twenty permanent young molars in 60 children aged 8 to 13 years received only one application of a light-activated resinous sealant. The retention rate was assessed 6 and 12 months later. The teeth were divided into 2 groups of 110 each. In one of the groups the pits and fissures were etched with 37% phosphoric acid before being sealed (group 1); in the other (group 2) these areas were etched with 10% maleic acid. The retention rate of group 1 was 98.4% at 6 months, and 96.8% at 12 months. Group 2 had retention rates of 97.5% at 6 months and 95% at 12 months. There was no statistically significant difference between the two groups in the two test periods, nor were there differences in the same group at the different periods.

Clinical evaluation of composite resin tunnel restorations on primary molars.

Twenty children, presenting 66 proximal carious lesions in 60 primary molars, were selected to receive composite resin tunnel restorations. Thirty of these teeth were expected to exfoliate within 6 months (group I); in the remaining 30 teeth exfoliation was expected within 1 year (group II). All teeth received tunnel preparations, which were then restored with a posterior composite resin. The restorations were evaluated after 6 months and after 1 year through each of the following methods: bitewing radiographic examination, clinical examination with a probe and mirror, and direct examination of proximal surfaces after tooth extraction. The occlusal portions of the restorations were considered to be excellent both after 6 months and 1 year. Radiographic examinations and direct examinations (performed after extraction of teeth) did not reveal the same percentages of secondary caries in the proximal portion of restorations. Fracture of the marginal crest reached 3% during the first 6 months, but fracture was absent during the subsequent 6 months.

Reattachment of a tooth fragment with a "new" adhesive system: a case report.

A maxillary central incisor fractured, invading the biologic width. The biologic width was surgically restored, and in the same session the fragment was reattached to the tooth remnant with a "new" dentinal adhesive system. Short-term results indicate that esthetics, function, and oral health have been maintained.

Coronal fracture with invasion of the biologic width: a case report.

To repair a coronal fracture with invasion of the biologic width, flap surgery with osteotomy and osteoplasty localized on the fractured tooth was performed, and the crown was reattached to the tooth remnant with a composite resin system. Results after 6 years revealed optimal periodontal health and reasonable esthetics.

Amalgam repair: a case report.

Through the report of a clinical case, the feasibility and advantages of repair and recontouring of complex amalgam restorations are discussed. In this patient, the kind of alloy used for the fractured restoration and the age of the restoration were known factors. Additional mechanical retention was prepared in both the "old" amalgam and the dentin, and the repair was made with a high-copper alloy. The bond at the repair site was stable at the 2.5-year recall examination.

The sandwich technique, an alternative treatment for tetracycline-stained teeth: a case report.

A patient whose teeth had been severely stained by improper use of tetracycline was treated through a direct system of facial veneering. The technique associates the use of a light-activating glass-ionomer cement with two kinds of light-activating composite resin. Satisfactory esthetics were obtained immediately.

Tensile resistance of complete cast crowns cemented on amalgam foundations retained by amalgapins.

An in vitro study was conducted to examine the influence of the number of remaining cusps and the use of the amalgapin technique on the tensile resistance of complete cast crowns in posterior teeth. Results showed the number of amalgapins and remaining cusps to have no influence on the tensile strength. Failure occurred predominantly at the cemented area (ie, the crown was dislodged from the core).

The "sandwich" technique as a base for reattachment of dental fragments.

Esthetics and function were restored to a fractured maxillary central incisor by reattaching the tooth fragment with the "sandwich" technique (glass-ionomer cement and composite resin). After 3 years, the tooth showed optimal fragment rehydration, presence of pulpal vitality, absence of sensitivity, and a discrete color alteration in the line between the fragment and the dental remnant.