Quintessence International, 11/1997

Rieger's syndrome is a rare autosomal-dominant disorder characterized by dental, ocular, and periumbilical abnormalities. Essential ocular features include goniodysgenesis, which leads to increased intraocular pressure and subsequent glaucoma and visual loss. Dental findings include midfacial hypoplasia and the absence of primary and permenet incisors and seond premolars. Comprehensive preventive dental care in the form of fluorides and sealants is required, especially in patients wi th severe hypodontia, to increase the resistance of the remaining teeth to dental caries. This article describes a case of Rieger's syndrome in a 9-year-old child and emphasizes the need for comprehensive oral rehabilitation.

This article reviews the current status and future prospects for glass-ionomer materials. These materials are of two chemical types: the older, self-hardening cements, which set by an acid-base neutralization reaction to give relatively brittle materials; and the newer, resin-modified ce ments, which set partly by polymerization and partly by neutralization. Compared with the self-hardening cements, the latter materials have improved esthetics, improved resistance to moisture, and greater toughness. Both types of glass-ionomer cement bond wel l to enamel and dentin and release a clinically useful amount of fluoride. They have been used in a variety of applications: as liners or bases, for luting of stainless stee l crowns, for Class V restorations in permanent teeth, and for Class II and Class III restorations in primary teeth. The resin-modified glass-ionomers are particularly promising for these latter uses, although it is too early to be sure whether their long-term durability is sufficient. Self-hardening glass-ionomer materials are likely to retain specific niches of clinical application, including in their metal-reinforced and cermet-containing forms.

Researchers have carried out a varity of investigations to determine the properties of available dentin bonding system. The test methods and variables used in 50 published investigations of bone strength were analyzed. Among the studies analyzed, shear tests predominated, being used in 80% of the studies; dentin from human molar teeth was used most often (in 88% of investigations); and the most prevalent time of testing was 24 hours postcuring. However, a number of potential varialbes were not recorded in a high proportion of articles, among these the film thickness, the type of dentin tested, and the surface condition (moist or dry). The mode of failure was reco rded in only 42% of the investigations assessed. It was found that htere is little standardization of test methods in studies of dentin bond strength and that a number of variables are often either not recorded or reporte

This research examined the effect of immersion in glutaraldehyde-based cold sterilizing solutions on the ability of light-curing tips to transmit a standardized light intensity. Five commercial cold sterilizing solutions were selected, based on their classification: neutral (Cetylcide-G, 3.2%), acidic (Banicide, 2.0%), or alkaline (Cidex Plus, 2.5%; Cidex 7, 3.4%; and Sporicidin, 0.5 %). Distilled water was used as the control. The light intensity transmitted through 24, 8-mm-diameter curing tips of similar type was determined by aplying a standardized intensity (500 mW/cm to the second power). Three tips were placed into each type of solution. The percentage of preimmersion intensity was determined at periodic intervals until all tips had received a total of 1,000 hours of immersion. After 1,000 hours; immersion, light transmission decreased significantly more in tips subjected to Cidex 7 than in tips subjected to all other treatments, which were all equivalent to the water control (an average increase of 1.5% over preimmersion values). The de crease in intensity seen with Cidex 7 averaged 49% and could not be totally recovered after use of sonventional tip-polishing methods. Reduction in light levels could not be correlated with the pH of the sterilizing solutions.

A maxillary canine and premolar showed a 3.0- to 4.0 - mm-deep and 3.0- to 4.0-mm-wide recession defect with 2.0- to 3.0-mm zone of attached gingiva. The denuded root surfaces were covered with nonkeratinized alveolar mucosa in a slightly modified bridge flap technique. The coronal displacement of a nonkeratinized alvolar mucsal flap onto a bed of collagenous gingival connective tissue resulted in the development of keratinized epithelium in the previously nonkeratinized mucosa. This was caused by the inductive stimuli of the underlying tissue and observed in the 6-month specimen. The alvolar mucosa displayed its transformed epithelial structural pattern only in segments, achieving full differentiation of its basal complex over a 10-year period, as demonstrated clinically and histologically.

A multidisciplinary panel of senior academics and practitioners has evaluated a system of prefabricated threaded split-shank posts (Flexi-Post/Flexi-Flange) from published research and their own clinical use. These posts have been compared with requirements of an ideal post system in relation to clinical use, stress effects, stress distribution, retention, loosening and displacement, provision for cores, and biocompatibility. The purpose was to provide this critical review to allow interested clinicians to compare this novel design to other available post systems.

Tuberculosis of the oral mucosa was associated with pulmonary tuberculosis in a 38-year-old white man. The patient presented with multiple oral ulcerations with an irregular periphery and a graunular vegetative fundus. The oral lesions antedated the findings of primary pulmonary tuberculosis, and the diagnosis was initially established histologically. Through the differential diagnosis of oral ulcerations, the dentist can play a role in the ea4l Tuberculosi of the oral mucosa was associated with pulmonary t uberculosis in a 38-year-old white man. The patient presented with multiple oral ulcerations with an irregular periphery and a granular vegetative fundus. The oral lesions antedated the findings of primary pulmonary tuberculosis, and the dignosis was initially established histologically. Through the differential diagnosis of oral ulcerations, the dentist can play a role in the early detection of tuberculosis.

A rare finding of unilateral heterotopia of a manidublar third molar was most probably caused by primary and total dislocation of the tooth base. Otehr possible causative factors, such as a lack of space between the mandibular second molar and the mandibular ramus or a disproportion between the base and the direction of growth of the third molar, have been considered in similar cases reported in the literature.

The aim of the study was to evaluatte in vitro the marginal seal in Class II resin composite restorations reinforced with glass-ceramic inserts. Forty Class II cavitie s, with the gingival margins located at the cementoenamel junction, were restored with Palfique Estelite light-cured resin composite and one of two different bonding agents, All Bond 2 and Tokuso Light Bond, with or without the inclusion of glass-ceramic inserts. The extent of dye penetration along the tooth-restoration interface was measured under an optical microscope. The marginal seal of composite restorations placed with All Bond 2 was significantly better than that of restorations placed with Tokuso Light Bond. There was significantly less microleakage in All Bond 2 restorations without glass-ceramic inserts than in All Bond 2 restorations containing glass-ceramic inserts. No significant difference in marginal seal was demonstrated between Tokuso Light Bond restorations with glass-ceramic inserts and those without inserts.