Accuracy of cast posts and cores using a new investigative method.

Generally, two techniques are used to fabricate a cast post and core (CPC): direct and indirect. To date, research has made no clear indication as to a comparative level of accuracy between the techniques. Therefore, the purpose of the current study was to compare the accuracy of two techniques to produce CPCs for posterior teeth using a new method. Nine endodontically treated human premolars were used for fabricating CPCs using the direct and indirect methods. A total of 18 CPCs were produced, two for each tooth, cast in high noble type IV gold. A silicone impression material was inserted into the root canals, followed by the CPCs. The remaining material in the space between the canal wall and the CPC was weighed using an electronic precision balance. By evaluating the weight of the silicon specimens, the accuracy and intimacy of fit were obtained. Since the number of samples was small, a Student t-test was used for statistical evaluation at a 90% confidence interval. The CPCs obtained by using each method were independently examined by two clinicians for proper fit. Power analysis indicated that for a 90% confidence interval and 0.8 power value, nine specimens would be necessary to achieve a statistically meaningful test. The mean value for the weight of the nine specimens obtained using the direct method was 10.3 ± 2.6 mg, while the mean value for the corresponding specimens obtained using the indirect method was significantly smaller, 7.4 ± 2.3 mg. The Student t-test value was P = 0.006. The indirect method provided CPCs with a better fit and higher accuracy. The Student t-test demonstrated a significant difference between the direct and indirect procedures. The indirect method is a valuable technique for the dental practitioner when multiple posterior cast posts and cores are necessary or interocclusal space is limited.

Sports drinks and dental erosion.

Sports drinks were originally developed to improve hydration and performance in athletes taking part in intense or endurance sporting events. These drinks contain relatively high amounts of carbohydrates (sugars), salt, and citric acid. These ingredients create the potential for dental ramifications and overall public health consequences such as obesity and diabetes. High intake of sports drinks during exercise, coupled with xerostomia from dehydration, may lead to the possibility of erosive damage to teeth.

Dentistry a la carte: in-office CAD/CAM technology.

This article examines the differences among four in-office computer-aided design/computer-aided manufacturing restorative technologies. Two acquisition media systems, 3M ESPE's Lava COS and Cadent's iTero, are compared and contrasted. Additionally, two acquisition and manufacturing media, Sirona's CEREC AC and D4D's E4D, are examined. Image acquisition techniques and cast fabrication methodologies are compared between Lava COS and iTero. In addition, image acquisition, cast fabrication, and restoration fabrication methodologies are discussed as related to CEREC AC and E4D. Strategies for computer-aided design/computer-aided manufacturing incorporation into practice are explored.

Realigning biomedical science instruction in predoctoral curricula: a proposal for change.

Currently in North America, there is an active dialogue going on about the state of predoctoral dental education and the need for curriculum change, innovation, and the adoption of contemporary, competency-based educational models. At the institutional level, curriculum committees struggle with requests from faculty to add new content to an overburdened didactic and clinic schedule. This article will describe potential solutions centering on the role and scope of the biomedical sciences in predoctoral dental education. The authors propose that dental educators and institutions reconsider the current admission prerequisites and curriculum content of the biomedical sciences in predoctoral programs. The proposed changes are intended to eliminate content redundancy between undergraduate and predoctoral dental education by integration of the biomedical sciences--in particular, biochemistry, microbiology, and physiology--into other clinically oriented coursework and learning experiences in the curriculum based on a pathophysiology model that fosters students' comprehension of the etiology of oral and systemic diseases encountered by the general dental practitioner. The authors explore how changes in the biomedical science prerequisites for dental school matriculation and associated modifications in curriculum focus and content would impact admissions testing, composition of national board exams, and strategies for teaching and learning within dental schools.

Simplified clinical procedure for fitting and removing inlays/onlays prior to cementation.

This article describes a procedure in which polytetrafluoroethylene (PTFE) tape is used as a liner for fitting intracoronally retained, indirect restorations. The minimal thickness of the tape allows complete seating and confirmation of marginal fit of restorations during try-in, yet the tape is tough enough to permit trouble-free removal of the restoration afterward. Protection against inadvertent loss of the restoration can be gained if a knot is placed close to the occlusal surface of the restoration prior to its removal.