Shear bond strength of four orthodontic bonding systems.

Recently new orthodontic bonding systems have been developed for attachment of brackets to the etched facial surfaces of teeth. Two of these new systems use bonding agents that contain solvents. It is claimed that this improves the polymerization of the unfilled resin primer and may increase bond strength.

Bonding glass-ionomer cements to chemomechanically-prepared dentin.

The aim of this investigation was to compare the shear bond strengths of two commercially available glass-ionomer cement base materials to remaining dentin: (1) after conventional caries removal and polyacrylic acid conditioning; (2) after chemomechanical caries removal (Caridex); and (3) after chemomechanical caries removal and polyacrylic acid conditioning. Ninety freshly extracted carious teeth were randomly assigned for caries removal with either the chemomechanical technique (N = 60), or with conventional mechanical drilling (N = 30). Caries removal was continued until the remaining dentin surfaces were judged sound.

A bond strength study of luted castable ceramic restorations.

Accurate intracoronal castings can be produced using a castable ceramic--DICOR--for which there is a need to identify a suitable luting cement. The aim of this investigation was to evaluate the bond strength of three glass-ionomer luting cements and one resin cement to treated and untreated DICOR, enamel, and dentin surfaces. Forty "cerammed" DICOR specimens were assigned to four groups: (1-3) grit-blasting and bonding to each of the three glass-ionomer cements; and (4) acid-etching, silane coating, and bonding to the resin cement.

Orthodontic bonding to porcelain--bond strength and refinishing.

Glazed porcelain surfaces are not amenable to resin penetration for orthodontic bonding. The aims of this study were to evaluate (1) the bond strengths of two orthodontic composite materials to treated porcelain surfaces, (2) the effect of thermocycling, and (3) the porcelain surfaces after refinishing. Sixty glazed porcelain disks were assigned to three surface treatment groups: Silane (S), roughening and silane (RS), and roughening (R).

Chemomechanical caries removal--a clinical evaluation.

The aim of this investigation was to evaluate the efficacy and convenience of decayed dentine removal with N-monochloro-DL-2 aminobutyrate (CARIDEX) in all classes of cavities. Fifty-seven patients, each with two teeth having similarly sized carious cavities, participated in this study. One cavity in each patient was treated with the chemomechanical CARIDEX technique and the other cavity was treated with conventional mechanical drilling.

Managing orthodontic data on a small computer.

A literature survey of file management, relational database management, and network/hierarchical database management systems led to selection of dBASE III to manage patient records on an IBM PC in the Department of Orthodontics at the Louisiana State University School of Dentistry. The versatility of this system's internal language enables ad hoc analysis of clinical and personal data to meet both anticipated and unanticipated management and scientific needs.

Daily release of copper from dental alloy restorations in a patient with Wilson's disease.

Wilson's disease is a rare genetic disorder in which copper accumulates in tissues. Its victims must adhere to a strict dietary regimen yielding less than 2 mg of copper per day. Three major variables have been identified as being of critical importance in the treatment of these patients: the amount of copper naturally occurring in foods, the amount of copper introduced during the preparation of foods, and the amount of copper in the environment.

The effectiveness of opaquer and color-modifier materials: a laboratory study.

New, direct bonding composite resin products are available for esthetic and restorative dentistry. As in vitro study was conducted to evaluate the stain-masking effectiveness of 57 opaquers or color modifiers. Results of the testing on 265 specimens are reported, ranging from minimal to excellent masking.

Retention of orthodontic bands with new fluoride-releasing cements.

The prevalence of enamel decalcification beneath orthodontic bands has indicated the need for a fluoride-releasing, enamel-adhesive orthodontic luting cement. The purpose of this study was to compare the retentive bond strengths of orthodontic bands cemented with two new fluoride-releasing cements, a zinc polycarboxylate and a glass ionomer, with the retentive bond strength of bands cemented with the standard orthodontic cement zinc phosphate. The site of cement failure was also evaluated.

The pulpal response to dilute citric acid smear removers.

The aim of this study was to determine the pulpal response to three dilute citric acid smear removers. Forty-eight vervet monkeys (Cercopithecus aethiops pygerythrus), in three groups of sixteen animals provided 384 tooth specimens for the histological evaluation of the pulpal response at 3, 31, and 59 days post-operatively. Labial Class V cavities were prepared in the maxillary and mandibular incisor teeth.

Force degradation of orthodontic elastomeric chains--a product comparison study.

In the last 20 years, synthetic elastic modules have been introduced to the orthodontist. However, force decay of these materials has been a clinical problem and the purpose of this project was to evaluate the force decay patterns of three commercially available elastomeric products--Ormco Power Chain II, Rocky Mountain Energy Chain, and TP Elast-O Chain--in a simulated oral environment. Thermal-cycled samples experienced less force decay over a 21-day period than samples stored at 37 degrees C.

Pulpal responses evaluated by two assessment systems. Use of Nobetec as negative and Super-Syntrex as positive control materials.

In the assessment of pulpal responses to dental materials there is no general agreement regarding which system should be used in the selection of histologic sections for assessment and which negative and positive control materials should be used. The present study is an evaluation, on 227 sections, of two pulpal assessment systems and three section-selection methods using a negative (zinc oxide and eugenol cement) and a positive (silicate) control material. The results indicate that, depending on which system is used, considerable variation in response can be noted.