Quintessence International, 02/1992

Since 1985, 534 severely discolored teeth have been treated with intentional endodontics and internal bleaching; of these, 258 were treated with the conventional technique and 276 were treated with the modified technique. Six years of clinical and radiographic evaluation revealed that the results obtained with the first group (conventional technique) remain stable and that a very noticeable improvement has been achieved with the second group of teeth, treated with the modified technique.

This paper describes a clinical case in which a combination bleaching technique was used to improve the appearance of the patient's discolored anterior teeth. Enamel microabrasion was used first to remove superficial fluorosis stains. A home bleaching regimen was then used to lighten the overall shade of the teeth, which had appeared more yellow after microabrasion.

Although there have been numerous technological devices introduced for the diagnosis and treatment of temporomandibular disorders, many are either ineffective or are research tools without direct clinical application. This article reviews the various modalities and makes recommendations regarding their effectiveness based on the available clinical and scientific evidence.

Bacterial plaque has been implicated as the primary etiologi factor in the initiation and progression of periodontal disease. Anatomic factors, such as cervical enamel projections, enamel pearls, and radicular grooves, are often associated with advanced localized periodontal destruction. Enamel projections and pearls are most often ass ociated with molars, while radicular grooves are usually located on the palatal aspect of maxillary incisors. Gingival fenestrations are of uncertain etiology and have rarely been reported in the dental literature. An unusual case is presented of a cervical enamel projection located on the facial aspect of a maxillary central incisor in association with gingival fenestration. Rationale for therapy and likely healing results are discussed

Eight mesio-occlusodistal adhesive inlays, fabricated from ceramic blocks using a computer-aided design/machining me thod, were reexamined after 5 years of clinical service. The inlays were evaluated according to modified US Public Health Service criteria. The results indicated excellent clinical performance, with eight Alfa ratings for wear, recurrent caries, and color match, and five Alfa and three Bravo for marginal discoloration and marginal integrity. Under scanning electron microscope, 81.0% of the tooth-cement interfaces and 84.1% of the cement-inlay interfaces were rated continuous at the occlusal margin. Axially, 73.6% of the tooth-cement interfaces and 87.0% of the cement-inlay interfaces were rated continuous. Although this long-term investigation revealed good clinical performance of the inlays, improvements in the ceramic structure and its properties, the cavosurface design, and the luting composite resin were recently introduced to further optimize quality.

The thermal side effects of carbon dioxide and neodymium:yttriumaluminum-garnet lasers limit their clinical applications. These high-powered, infrared lasers res ult in zones of charring and carbonization even in soft tissues and the bone. In contrast, the pulsed, ultraviolet radiation emitted by excimer lasers causes limited thermal, denaturative damage to surrounding tissues. Therefore, treatment of dental tissues with the nonthermal process of photoablation with excimer lasers may present alternatives to traditional dental practice. Possible future applications of the excimer laser include selective caries removal, the conditioning of tooth surfaces, and cleaning of root surfaces; the zones of necrosis are small, so that there is no residual debris.

The present study investigated the bond of 5% 4-methacryloxyethyl trimellitate anhydride in methyl methacrylate, initiated by partially oxidized tri-n-butyl borane in the presence of poly(methyl methacrylate) power, to vital human dentin. In vivo dentinal substrates were pretreated for 10 or 30 seconds with an aqueous solution of 10% citric acid and 3% ferric chlo4ride. Transmission electron microscopic examination of the bonded cross sections revealed the formation of a transitional, or hybrid, layer of resin-reinforced dentin created by the impregnation, co-mingling and envelopment of collagen bundles, and encapsulation of hydroxylapatite crystals. The in vivo adhesion was assumed to be durable, because results of microscopic examinations were comparable to those of durable bonding of the same resin to extracted bovine dentin. Vital dentin exhibited greater resistance to demineralization by the acid solution than do extracted teeth. Carious extracted teeth were more easily dissolved in acid than were noncarious extracted teeth.

The purpose of this in vitro study was to evaluate differences in initiation and progression of carieslike lesion s around restorations in enamel. A demineralization/remineralization cycling model was used to induce experimental secondary caries around cavities restored with glass-ionomer cement or composite resin. The effects of these materials were compared by microhardness profiles. The results indicated that glass-ionomer cement showed potential value as a restorative material for the prevention or reversal of caries in enamel adjacent to restorations, even in situations of high cariogenic challeng