Quintessence International, 08/1996

Allergies related to dentistry generally constitute delayed hypersensitivity reactions to specific dental materials. Although true allergic hypersensitivity to dental materials is rare, certain products have definite allergenic properties. Extensive reports in the literature substantiate that certain materials cause allergies in patients, who exhibit mucosal and skin symptoms. Currently, however, neither substantial data nor clinical expe rience unequivocally contraindicate the discontinuance of any of the materials, which include dental amalgam and nickel-and chromium-containing metals. The dentist forms a vital link in the team approach to the differential diagnosis of allergenic biomaterials that elici stymptoms in a patient, not only intraorally, but also on unrelated parts of the body.

The development of hydrothermal ceramics was an important requirement for fusing hydrolysis-resistant ceramics to precious metal alloys with low melting interval. Clinical findings since 1992 confirm the wide range of application of these metal-ceramic restorations in dentistry. Initial problems concerning temperature regulation of the ceramic ovens were rectified by checking and adjusting them for lower sintering temperatures. The golden yellow color is only one advantage of the ceramic-veneered alloy. Other advant ages include its nonporous, smooth surface, translucence, and suitability for use in all types of dental restorations and reconstructions. Hydrothermal ceramic veneers thus can help to substantially reduce the number of different alloys used in a patient's mouth.

When the abutment teeth of a fixed partial denture are severely misaligned, insertion of the prosthesis becomes more difficult. Some of the methods traditionally recommended to overcome the problems associated with this situation are examined. One design that simplifies treatment and improves the prosthesis is suggested.

Two new implant systems, the Compound Implant and the TFM coping/abutment, are based on the association of titanium in the infrabony portion and a dense milled ceramic in the transgingival portion. The coating of zirconium ceramic on the transmucosal collar of the Compound Implant particularly indicated for a single-stage surgical implant technique. The isolating properties and the high wettability of this material favor gingival healing and reduce the accumulation of plaque: the esthetic collar permits a supragingival or juxtagingival cervical margin favoring plaque control and minimizing the consequences of tis sue remodeling. The hardness of the ceramic also allows it to undergo conventional prophylaxis with ultrasonic scalers without alteration of its surface quality. In addition to the above-mentioned advantages, the TFM coping/abutment, an implant-prostheis connector in alumina ceramic, for use in a two-stage technique, provides electrogalvanic isolation of the implant, and personalized abutment preparation allows for simplified fabric ation of an implant-supported prosthesis.

The comfort on administration and effectiveness of electronic and local anesthesia for operative procedures, as perceived by clinicians and patients, were compared based on a 5-point Lickert scale, and a survey to solicit pati ent's feedback on the use of electronic anesthesia was conducted. Thirty patients, who required restorations on s imilar teeth bilaterally, and 10 clinicians were involved in the study. The two teeth in each patient were randomly restored under either electronic or local anesthesia. Administration of electronic anesthesia was perceived to be significantly more comfortable than that of local anesthesia, by both clinicians and patients. Local an esthesia was perceived to be significantly more effective by both evaluator groups, but 93.3% of the patients still preferred electronic anesthesia and would use it again. Minor after effects in some patients included redness of skin and briefly lingering sensation. All patients found electronic anesthesia easy to sue, and most of the patients (93.3%) thought that the system was good to excellent.

Melanin is normally found in the skin of all people, and normal pigmentation of the intraoral tissues is a relatively frequent finding. The highest rate of gingival pigmentation has been observed at the incisors. Until recently, however, very little attention has been paid to the esthetic treatment of sever gingival pigmentation. To answer the cosmetic demand for a pleasing smile, pigmented gingiva was replaced with an unpigmented free gingivasl autograft in 10 patients. AT least two areas in each patient were grafted. In all 10 areas in which the recipient site received full-thickness bed preparation , no evidence of repigmentation was found after 4.5 years. Of the 10 areas that received partial-thickness bed preparation, only one exhibited repigmentation (after 1 year

The color of manufacturers' shade guides was compared with the color of the actual resin composites. Five light-activated resin composite products were evaluated. Resin specimens and shade guides of same thickness were measured with a spectrophotomerter. Color differences (AE* values) were more than perceptible in all products. The mean AE* values were least in Z100 and greatest in Herculite XR. Generally, the L* and b* values of the shade guides were higher than those of the resin composites. Some colors showed color differences greater than the acceptable level.

A denture plaque index using the dye disclosing method was evaluated in 24 patients with Type II denture stomatitis and 17 control subjects with healthy palatal mucosa. Patients with denture stomatitis had statistically significantly higher plaque scores than did controls, indicating a quantitative increase in denture plaque in patients with denture stomatitis. When this plaque index was tested by two examiners for intraexaminer and interexaminer reproducibility, it yielded a 92% to 96% reproducibility. The plaque index used in this study seems to satisfy the criteria for an ideal clinical index: It is simple, reliable, reproducible, and economical and can be carried out in the shortest possible time in a clinical setting.