Simplifying single-stage solid abutments: Part 2. Temporization

Fabrication of a temporary crown can consume much chairside time when restoring a single-unit implant. A technique for rapid fabrication of a temporary crown for the ITI implant system is addressed so as to minimize time and provide an accurate-fitting esthetic interim crown.     

Computerized milled solid implant abutments utilized at second stage surgery

Single tooth restoration with implants traditionally has been complicated due to the difficulty in achieving ideal emergence profile and crown form. The Atlantis milled abutment overcomes these difficulties, utilizing CAD/CAM technology to develop a customized milled abutment with ideal emergence profile and shape to simplify crown fabrication.     

Options for the fabrication of provisional restorations for ITI solid abutments

In this article, 4 techniques for fabricating provisional restorations for ITI solid abutments are described. The use of a burn-out coping, acrylic resin coping, impression cap, and protective cap are presented, and the advantages and disadvantages of each are discussed.     

A 2-year longitudinal study of overdenture patients. Part I: incidence and control of caries on overdenture abutments.

1. The development of caries on overdenture abutments is a significant problem. In the patients examined, a high incidence of caries was noted at each recall. While few teeth were lost due to caries (none by first recall, none by second recall, and four by third recall), many teeth can eventually deteriorate and be lost (Fig. 7). 2. Caries can develop in a short period of time as shown by the results of the initial examination (caries present 2 to 8 months after insertion of the overdenture). 3. Some patients seem to be caries susceptible, as shown by the recurrence of caries, notwithstanding caries removal from the overdenture teeth at each recall. For example, a large percentage of patients with caries at the 1-year recall also had caries at the 2-year recall. 4. Patients who were placed on fluoride solution and/or had teeth treated with silver nitrate had a significant decrease in caries when compared to those who received no treatment or were placed on a placebo. 5. Fluoride caused some irritation or burning sensation in tissues of several patients. This was relieved in several patients by a decrease in the frequency of application from daily to 2 to 3 times a week.     

Zirconia implant abutments: microstructural analysis

Purpose: Yttria-stabilized zirconia (ZrO2-Y2O3) ceramics have received increasing attention in recent years because of their stress-induced tetragonal-to-monoclinic (martensitic) transformation. This unique process acts as a toughening mechanism, imparting strength and toughness to the ceramic alloy. This property, along with well-documented biocompatibility, is now being exploited in an increasing number of medical applications, including implant dentistry. To prevent clinical problems and predict their behavior and physical limitations, a characterization of the ceramic elements used in dental restorations is essential. The aim of the present study is to characterize the crystal structure, elemental composition, and micr ostructure of asreceived ZiReal Post (Biomet 3i) zirconium oxide abutments, as well as specimens coated with a first layer of a low-fusing fluoroapatite ceramic. Materials and Methods: Zirconium oxide abutments, both as-received and porcelain-coated, were studied using the following techniques: x-ray diffraction, x-ray fluorescence, energy dispersive x-ray spectroscopy, optical microscopy, and scanning and transmission electron microscopy. Results: X-ray analyses detected only the presence of Zr, O, Y, and hafnium (Hf), in an amount of 3% to 4% molecular weight Y2O3-ZrO2. X-ray diffraction measurements showed that the ceramic abutment crystallizes mainly in the tetragonal phase, with some residual monoclinic phase. The microstructure is characterized by a rather homogenous grain distribution, formed by equiaxed and fine grains with a mean size of 0.30 Μm. Conclusions: Compositional and diffraction results are consistent with polycrystalline yttria-stabilized tetragonal zirconia. The material is susceptible to undergoing the stress-induced transformation toughening mechanism because of the very fine grain size. Except for machining ring marks, the surfaces exhibit an excellent finishing quality. No structural modifications were observed in the fluoroapatite ceramic-coated abutments because of the relatively low temperatures used for ceramization compared with the phase transformation temperatures used for zirconia.