Three-way trays: easy to use and abuse.

The 3-way tray technique is popular as it provides master and opposing arch impressions and an interocclusal record at the same time. Excellent clinical results can be achieved with appropriate case selection, use of rigid tray and impression materials, attention to tray positioning and other details throughout the process, and clear understanding of the limitations of the technique by the operator and dental technician.

Advanced placement, qualifying, and degree completion programs for internationally trained dentists in Canada and the United States: an overview.

Canadian and U.S. universities are faced with the challenge that they are not graduating enough dentists to meet the future needs of the Canadian and U.S. populations. Foreign-trained dentists represent a valuable resource to society and the economy. Dental programs have been established to train foreign-trained dentists for some or all of the following reasons: public need for health care services, income generation for universities, and demand by foreign-trained dentists who desire to practice dentistry in Canada or the United States rather than in their own nation. Changes implemented by the National Dental Examining Board (NDEB) of Canada in 2000 and by the Commission on Dental Accreditation (CODA) in the United States in 1986 have resulted in foreign-trained dentists no longer being able to gain dental licensure in these countries strictly through a certification examination. Foreign-trained dentists are now required to apply for and complete a two- to three-year advanced placement, qualifying, or degree program at a Canadian or U.S. dental school prior to receiving licensure to practice. The study reported in this article investigated the various types of advanced placement, qualifying, or degree programs available to foreign-trained dentists wishing to practice in either Canada or the United States and the differences among these programs. This research provides a better understanding of the various commonalities and differences among Canadian and U.S. programs for internationally trained dentists.

The effect of metal ceramic restoration framework design on tooth color.

STATEMENT OF PROBLEM: The opacity of the metal framework in metal ceramic restorations results in reduced light transmission through the tooth that diminishes the esthetics of the tooth. PURPOSE: The purpose of this study was to investigate the color change that occurs apically to a metal ceramic restoration as a result of altering the metal framework design. MATERIAL AND METHODS: Color change relative to the unprepared tooth (DeltaE) between various metal ceramic restorations was determined using computer imaging and CIELAB coordinates and compared to previously determined levels of clinical acceptability. Color change was evaluated by examining 2 conditions (the metal copings and the completed metal ceramic restorations), 4 framework designs (metal collar and porcelain margins with 0-mm, 1-mm, or 2-mm cutbacks), and 2 locations on the tooth apical to the margin of the restoration, using an imaging system developed at the Minnesota Dental Research Center for Biomaterials and Biomechanics. The data were analyzed statistically using repeated measures analysis of variance (P=.05). RESULTS: For metal ceramic restorations there exists a significant (P=.001) color change (DeltaE) between all framework designs except for the 0-mm and 1-mm cutbacks. Color change (DeltaE) in the location above the cemento-enamel junction was significantly greater (P=.004) than below the cemento-enamel junction. CONCLUSIONS: The framework design for metal ceramic restorations can affect the esthetics of the adjacent natural tooth. A minimum 2-mm facial cutback of the metal framework is necessary for there to be a significant difference in color change.