Quintessence International, 08/1999

In the 25 years since the first resin-bonded prosthesis was described, this adhesive technique for splinting mobile teeth has developed into a conservative method for replacing missing teeth. There was a high debond rate associated with the early resin-bonded prostheses, which led many clinicians to question their clinical appropriateness for long-term use. These early failures were attributed to the limited bond strength between the metalwork and etched enamel. Despite improvements in the adhesive bond strengths, there was still an unacceptable number of clinical debonds. The biomechanical design of resin-bonded prostheses did not develop with the same rapidity or with the same predictability as did the advancements with the associated adhesive technology. Through ongoing development, studies have shown various biomechanical designs that may improve clinical retention. The purpose of this article is to examine the biomechanical principles for current resin-bonded prosthesis design, including aspects of tooth preparation and framework design that will improve clinical retention.

Objective: The aim of this study was to compare the effectiveness of the automated Interclean Interdental Plaque Remover with that of interdental brushes and Ultrafloss. Method and materials: The interdental hygiene effectiveness of 35 healthy patients suffering from gingivitis was studied by an examiner daily over a period of 1 week. The sizes of the interdental spaces were classified and corresponding-sized interdental brushes or floss was selected. In a random, split-mouth design both interdental cleaning methods, mechanical and manual, were applied while the patients continued to use standard brushing techniques. Disclosed proximal plaque, the papillary bleeding index, and interdental bleeding tendency on stimulation were evaluated. Results: The papillary bleeding index was reduced from an average value of 40% to 25%. Only 5% of interproximal plaque remained after manual interdental cleaning, whereas 40% of plaque was still present after use of the Interclean device. Cleaning efficiency of manual and mechanical methods was comparable in only 1 interproximal space size. At the end of the study, the interdental bleeding on stimulation was significantly higher in the automatically cleaned interspaces than in the manually cleaned spaces. Conclusion: Manual interproximal cleaning was more effective than the automated device.

Using only 7 programs, Orthophos Plus permits transverse conventional tomograms of all maxillomandibular regions. The precision of the magnification factors of these programs is very high. Factors influencing the image quality of the 7 programs were assessed. Image quality depends on technical precision and on correct patient positioning, ie, jaw axis alignment to the direction of projection. This procedure with 7 programs is more demanding than the procedure for x-ray units that use many programs for the different projections. Especially for implantology, it is important that the patient's jaw be positioned in accordance with the projection to avoid oblique cuts and incorrect information about the jaw dimensions. The correct region is best selected by positioning a cast in the positioning aids prior to exposure and using the same setting for the patient's exposures. For correct implant planning, it is helpful to digitize the tomograms with Friacom so that, despite different magnification factors of the programs, the correct implant dimensions are determined. If these suggestions are followed, use of these programs in dental practice can be recommended.

There are still no replacement materials on the market that are equal to amalgam. However, alternatives of differing qualities are available and, for the most part, clinically proven. This article attempts to make a scientific and clinical comparison of these alternatives with respect to esthetics, biocompatibility, chemical durability, and treatment cost. The evaluation suggests that cementable restorations, in particular electroformed inlays and onlays, are superior to bonded ceramic inlays.

A gold-acrylic resin abutment for a removable partial denture was esthetically and functionally restored with a bonded Artglass facing. Surface preparations utilized were intraoral sandblasting and tin plating. An adhesive resin composite, Panavia 21, bonded the new Artglass facing to the prepared gold surface of the abutment.

A case report is presented in which continuing root formation occurred in a carious nonvital and immature mandibular second premolar after single-visit calcium hydroxide apexification treatment. An apical hard tissue barrier was formed, accompanied by a separate, mesioapically growing root, 7 months posttreatment. Treatment was concluded with gutta-percha root canal restoration. The success of this single-visit apexification treatment supports the contention that frequent changing of the calcium hydroxide dressing is not always required to induce apical closure.

During the 19th century, dentistry was changing from a craft that was usually transmitted by a preceptor to a science that was taught in established schools. The first dental school, established in 1827 in Bainbridge, Ohio, was soon followed by a large number of proprietary and freestanding schools of dentistry. However, no matter what the status of the dental school, none would admit women. In contrast, the first woman to be admitted to a medical college graduated in 1849. The Ohio College of Dental Surgery was the first dental school to open its doors to a woman and granted a degree to Lucy Beaman Hobbs Taylor in 1866. Although the number of women to graduate from dental school increased, the number was small compared to the increase in male graduates. By 1893, about 200 women had graduated with degrees in dentistry, including a number who came from outside the United States.

Objective: This study examined the shear bond strength of bonding agents to normal or fluoridated enamel following use of weak or strong acids to prepare enamel surfaces and after contamination with a measured amount of saliva at various stages of the bonding procedure. Method and materials: One hundred extracted human third molar teeth were randomly separated into 2 basic groups (normal or fluoridated teeth), then divided into 5 subgroups. Group A specimens were not contaminated. After etching, enamel surfaces were dry and clean. Group B was left with wet surfaces after etching. Group C specimens were contaminated with artificial saliva and then dried. Group D specimens were contaminated with artificial saliva, rinsed, and then dried. In group E, all enamel surfaces were left contaminated with saliva after the etching procedures (with maleic acid or phosphoric acids). Adhesive resins were applied to all enamel surfaces according to the manufacturer's instructions. The specimens were then mounted and tested to determine shear bond strength. Results: If normal enamel surfaces were rinsed and dried immediately after contamination, there was no significant reduction of shear bond strength of adhesive to enamel. Specimens in group E and group C had significantly lower bond strengths than did control specimens (group A). In the fluoridated groups etched with the phosphoric acid, statistically significant reductions in bond strengths were obtained in all contamination groups and in the control group. In the fluoridated specimens, there were no statistically significant differences between any of the contamination groups and the control group when maleic acid was used. Conclusion: Saliva contamination may not be a risk factor for successful bonding between bonding agent and dental tissues for normal or fluoridated enamel surfaces if they are rinsed and dried immediately after contamination. Etching of normal enamel surfaces with phosphoric acid in the presence of contamination may provide higher shear bond strength than etching with maleic acid.