Quintessence International, 12/1992

Dentinogenesis imperfecta is a localized form of mesodermal dysplasia of the dentin affecting both the primary and permanent dentitions. Most previous reports on dentinogenesis imperfecta describe treatment with overdentures, which have several disadvantages. The present report describes a case of dentinogenesis imperfecta in an 11-year-old girl. A combination of restorative, prosthetic, and surgical treatment was used to resolve the condition.

Oral amalgam tattoos are typically asymptomatic, benign, solitary or multiple clinical lesions produced by inadvertent placement of dental silver amalgam restorative material into the oral soft tissues. Diffuse lesions often display a grayish brown discoloration while other tattoos pres ent a darker blue-black contrast. One hundred sixty-eight biopsy reports that confirmed the diagnosis of amalgam tattoo were analyzed to find age, sex, and race of the patients and size, location, and duration of occurrence of the lesions. Among the 168 cases, 235 individual tissue specimens were identified. A majority of the specimens were taken from the buccal mucosa, gingiva, and alvolar mucosa. The most common site for the lesion was the mandibular arch. The size of the individual specimens ranged from 0.10 cm to 1.50 cm. Almost two thirds of the specimens were 0.40 cm or less.

The issues of bone necrosis and implant bed congruency are both central to the success or failure of endosseous dental implants to achieve osseointegration. Use of internally irrigated drilling instruments has been postulated to minimize bone necrosis. The ability of the cutting instruments to produce a smooth, congruent implant bed and retain fine bone structures is also critical to achieving primary integration. In the experiment conducted, the use of internally cooled instruments reduced the likelihood of thermal bone damage, particularly when trephine mills were used. Trephine mills weraeble to retain the fine bone structures of the walls implant bed site. No visible degradation occurred from multiple uses of the instruments.

Severely fractured anterior teeth often require immediate repair, while long-term restoration is delayed until a healing period is completed. This paper details a technique of immediate emergency repair of a fractured mandibular incisor followed by placement of a bonded composite resin complete-coronal restoration months later. Careful diagnosis, gentle handling of the freshly traumatized tooth and surrounding tissues, and ideal selection and use of the respective bonding materials are necessary to ensure eventual replication of form, function, and tooth shade when the long-term restoration is placed.

The effect of bleaching extracted teeth on the microleakage of subsequently placed Class V composite resin restorations was evaluated. Ten extracted premolars were stored in water at 37 degrees C to serve as controls. Ten premolars were exposed to a carbamide peroxide gel for three 2-hour periods per day for 9 days. These specimens were stored in water at 37 degrees C except during treatment periods. Class V cavity preparations were then placed at the cementoenamel junction of the facial and lingual surfaces of all teeth. Half of the teeth of each group were resoted with Scotchbond 2/Silux Plus and half were restored with Prisma Universal Bond 3/AP.H. After 24 hours of storage in 37 degrees C water, the teeth were thermally stressed for 100 cycles. Microleakage was assessed by dye penetration. The results demonstrated that prerestorative bleaching did not affect the marginal seal of subsequently placed restorations.

The objective of this clinical study was to determine the ability of an ultraconservative, sealed composite resin restoration, without a traditional cavity preparation and without the removal of the carious lesion, to arrest Class I caries. Tooth preparation was limited to placing a bevel in the enamel. These restorations were compared, over 6 years, with (10 ultraconservative, localized, sealed amalgam restorations with no extension for prevention and (2) traditional, unsealed amalgam restorations with the usual extension for prevention outline form. Caries was arrested by the ultraconservative, sealed composite resin restorations for 6 years. Complete sealant retention on the sealed amalgam restorations was somewhat lower than that on the sealed composite resin resotrations; conversely, p artial sealant retention was higher for the sealed amalgam group. The marginal integrity of the sealed amalgam restorations was significantly superior to that of the unsealed amalgam restorations. The sealant also protected Class I posterior composite resin restorations against wear.

Reported studies have implicated eugenol in the reduction in retention of restorations luted with chemically cured composite resin cement. This study investigated the effect of residual eugenol in the root canal on the retention of ParaPost dowels cemented with Panavia EX composite resin. An attempt was also made to identify and to determine the most effective cleansing procedure. Findings of this study demonstrated a substantial decrease in retention of posts luted with Panavia composite resin cement in the presence of eugenol. Irrigation with ethyl alcohol (ethanol) or etching with 37% phosphoric acid gel was found to be effective in restoring the resistance to dislodgment of the posts, but alcohol produced the most consistent and reliable results.

The resistance to fracture of jacket crowns, fabricated of cast glass-ceramic and five traditional ceramics, was evaluated. Four identical jacket crowns of each type were constructed on absolutely equal dental abutments in epoxy resin, obtained from a primary mandibular molar. An increasing load was then applied to the mesiobuccal cusp of each of the 24 crowns. Although the glass-ceramic proved to have the highest fracture resistance, it was not significantly stronger than three other traditional ceramics; neither did it seem to be suitable for constructing jacket crowns on posterior teeth.