Noah Stern

Principles of preparing endodontically treated teeth for dowel and core restorations.

Abstract The dowel and core should possess a positive seat to prevent a wedge-like action of the post. The transverse and vertical shape of the prepared root canal should follow the contour of the exterior root surface. The dowel length should be determined by the bone support of the involved root.

Effect of impression materials and techniques on the marginal fit of metal castings

The effect of two impression materials used in three different techniques was tested for the accuracy of the marginal fit of metal castings. Sixty identically prepared Ivorine teeth were divided into groups of 20. The following methods were selected to make impressions: (1) putty in a metal stock tray with simultaneous elastomeric impression wash, (2) copper band relined with autopolymerizing acrylic resin and subsequent light-body elastomeric impression material, and (3) copper bands with modeling compound. Faciolingual sections of the Ivorine teeth with cemented metal castings were examined by scanning electron microscopy (SEM) at x 100 magnification. Measurements of the thickness of cement layers were calculated both manually and by use of a recently developed computerized method. The differences in the gingival marginal gaps between various impression materials and techniques at both the facial and lingual surfaces were not statistically significant.

A CAD/CAM system for the production of metal copings for porcelain-fused-to-metal restorations

A computer-aided design and manufacture system for the production of metal copings for porcelain-fused-to-metal restorations is described and evaluated. The three stages of production: digitizing, mathematical processing, and milling are described, with emphasis on the systems ability to produce metal copings for both single-unit and multiple-unit restorations. Evaluation of the marginal fit of the produced copings demonstrates the potential for clinically acceptable results.

Mouth-operated devices for handicapped persons

A mouth-operated device designed for paralyzed persons was described. This device enables invalid persons to perform simple, everyday actions. The uses and advantages of the instrument as compared to other types were discussed.

A direct pattern technique for posts and cores

Abstract A practical direct impression technique for making posts and cores has been described. Cold-curing acrylic resin is used for making the pattern.

Porcelain surface texture after reduction and natural glazing

all the available restorative materials, the gingiva responds best to restorations made of porcelain. This is explained by the ability of porcelain to attain a smooth, polished surface.’ Restorations with a smooth surface, such as those of porcelain, greatly impede the accumulation of plaque and thus reduce the incidence of gingival infiammation.2*3 Another advantage of porcelain restorations is their esthetic appearance. This is attributable to the surface texture of the restoration, which is characterized by reflection and absorption of light rays. Such a desirable effect is achieved only if the surface of the restoration is optimally smooth.’ Fig. 1. Porcelain sample in porcelain mold.

A temporary space maintainer using acrylic resin teeth and a composite resin.

A one-session technique for preparing a temporary space maintainer has been described. The technique consists of attaching an acrylic resin pontic to etched surfaces of natural adjacent teeth by means of a composite resin. The main advantages of this technique are elimination of premature tooth preparation, good esthetics, fair strength, low cost, and rapid completion of the restoration without the need of a dental laboratory.

The tilted posterior tooth. Part I: Etiology, syndrome, and prevention

Abstract The extraction of a tooth may have far-reaching ramifications on adjacent teeth, opposing teeth, occlusal scheme, and the periodontium. The best treatment is prevention.

The modified Hawley occlusal splint

The use of occlusal prostheses is reviewed from the beginning of the twentieth century. The modified Hawley occlusal splint is described as it is used in integrated treatment in oral rehabilitation. The aims of treatment with the modified Hawley occlusal splint are listed and explained in detail. Contraindications and abuse of the Hawley occlusal splint are discussed also.

Temporary space maintainers retained with composite resin. Part II: Fracture load in vitro.

The average fracture load during occlusal loading of pontics which were bonded to natural abutment teeth in vitro was found to be 56.1, 57.5 and 74.2 kg for natural, acrylic resin, and Restodent pontics, respectively. Coating the roots of the abutment teeth with a thin layer of silicone rubber before embedding them in stone slightly reduced the strength of the fixed partial dentures. Thermocycling the specimens with coated roots caused a considerable decrease in strength to fracture loads of 33.0, 17.9, and 37.3 kg for natural, acrylic resin, and Restodent pontics, respectively. Fracture of the enamel of natural tooth pontics was observed in a few specimens. The superior strength of the fixed partial dentures with natural tooth and Restodent pontics would indicate that these pontics are superior for clinical trials rather than acrylic resin pontics.