Quintessence International, 05/1995

The options for correction of unesthetic teeth are numerous; among these treatments, porcelain veneers have received substantial attention from the profession and patients. The increase in dental health awareness and advances in dental materials and technology, such as the acid-etching technique, improved physical properties of composite luting resin, and the use of silane coupling agents, have contributed to the success ceramic veneers enjoy today. However, no single material or technique is without its limitations. This article therefore aims to review the criteria for case selection and the limitations of porcelain veneers in restorative dentistry.

This article describes a technique for fabricating a custom acrylic resin shell that will ensure a properly designed amalgam core for the coronally debilitated, endodontically treated posterior tooth. A few simple procedures result in a core foundation for root protection, an ideal crown preparation, and a more predictable final restoration.

The cervical margins of crowns are often placed subgingivally to satisfy patients' demands for esthetics, even though subgingival margins can adversely affect gingival health. Photographs of 527 Saudi citizens (285 men and 242 women) with natural and exaggerated smiles were recorded to determine if subgingival margins are always necessary. The photographs indicated that a substantial percentage of the participants did not display the gingival tissue of their anterior teeth during a natural smile. (Percentages ranged from 43.5% to 69.8% of maxillary teeth and from 93.7% to 97.9% of mandibular teeth). The percentage of subjects who did not reveal the gingival tissue of their maxillary anterior teeth during an exaggerated smile ranged from 22.7% to 39.3%; the percentage for mandibular anterior teeth ranged from 54.1% to 72.7%. There was no statistically significant difference between men and women regarding visibility of anterior teeth. Thus, a substantial number of these subjects could receive anterior crowns with supragingival margins without sacrificing esthetics.

Bacterial contamination of the wate supply of newly dental units was investigated. Water samples were collecged from water supply lines to the dental operatories prior to connection of the dental units. Within hours following connection, and continuing for up to the 6 months of the study, water samples were obtained from the air-water syringe of the units. The samples were serially diluted 10-fold and plated on culture media for quantitative analysis. The formation of bacterial biofilm in the dental water supplying tubing was monitored by scanning electron microscopy. The results of these studies revealed that the building's water supply to the dental units was contaminated prior to connection to the units. The water supply from the air-water syringe was therefore contaminated as well. The number of contaminant bacteria in the dental unit water supply increased for several weeks and then stabilized. The lumen of the dental tubing became progressively contaminated with bacterial biofilm, which subsequently became the primary reservoir for maintenance of the contamination of the dental unit water suply.

This case report highlights the dental implications of some features of Prader-Labhart-Willi syndrome. A 5-year-old child with this syndrome presented with a severe form of dental caries. The need for early dental consultation and preventive dental procedures is stressed.

This article reports the ocurrence of mesiodentes in three siblings. The etiology of this condition is discussed and genetic considerations, such as modes of inheritance and prevalence, are discussed.

Many teeth with apical involvement show apical external resorption, and become difficult to treat. A patient with severely damaged, periapically compromised permanent molar was treated successfully with a combination of simple root canal therapy and a conventional amalgam restoration. This method offers an inexpensive and predictable alternative and provides the option for a different restorative approach in the future.

The purposes of this experiment were to determine if resin-modified glass-ionomer cements are less sensitive to moisture than are conventional glass-ionomer cements, to investigate the effects of barrier coatings, and to study the effects of different setting environments. Discoid specimens of a variety of resin-modified glass-ionomer materials and a conventional glass-ionomer cement control were stored in different environments and were protected with different barrier coatings. The diametral tensile strengths of the specimens were determined and analyzed with three-way analysis of variance. Resin-modified glass-ionomer cements are less sensitive to moisture than is the conventional glass-ionomer cement control. Drier environments produced stronger resin-modified glass-ionomer strength, and the individual materials differed in strength.

The case of a 30-year-old man with aglossia is reported. Aglossia, a rare condition, is a developmental disorder, in which the entire tongue is absent. It is usually associated with jaw and facial anomalies. In this patient, both the maxilla and mandible were affected. Although the mortality rate of patients with aglossia is high, this patient has been able to cope with his oral function with minimal obstruction.

The aim of this study was to establish the effects of the working speed, the use of coolant, and the pressure applied on the temperature of the pulp when resin composite restorations are finished and polished. One hundred eighty teeth with resin composite restorations were randomly distributed into groups to be finished and polished with violet, blue, or yellow flexible disks. Each group was randomly subdivided into six subgroups of 10 each. Four subgroups were finished and polished, without water cooling, under constant pressure at speeds of 10,000, 8,000, 6,000, or 4,000 rpm. the other two subgroups were finished and plished at 10,000 rpm, one without water cooling while work was carried out intermittently and the other with water cooling while work was carried out constantly. Results impled that a maximal speed of 4,000 rpm should be applied when polishing is carried out continuously without water coolant. When water cooling is used, flexible disks can safely be used at a speed of 10,000 rpm and with continuous pressure.