Prevalence of teaching apical patency and various instrumentation and obturation techniques in United States dental schools.

Maintaining an open apex beyond the apical constriction with an endodontic file during canal instrumentation is a concept that has been advocated by several authors and clinicians. To ascertain the prevalence of teaching the patency concept as well as various instrumentation and obturation techniques in the United States dental schools, a survey was conducted. Forty-eight out of a total of 53 dental schools (91%) responded to the survey. Results indicate that 50% of the schools surveyed teach the concept of patency to their undergraduates or graduates or both; 83% teach a step-back instrumentation technique; and 89.6% teach lateral condensation of gutta percha as their primary obturation technique.

The effect of a multimedia interactive tutorial on learning endodontic problem-solving.

New technology may create additional opportunities for learning in dental education. One of these new features is a multimedia approach, courseware combining sound, text, stills and video with interactive learning. A multimedia program was developed to train dental students and dental practitioners in decision making and problem solving in endodontics. This study compared the effects of the multimedia program with a more traditional approach consisting of written information, without interaction. 28, 4th-year dental students at the University of Kentucky in Lexington, KY, USA were randomly assigned to the multimedia or the text-based groups. They were given a written pre-test using 2 cases of dental pain and were instructed to study independently using either the multimedia program (group A) or the written information (group B). No restrictions were imposed on the amount of time to be invested, and the total study time was recorded for each student. 3 weeks after the pre-test, the students completed the post-test. A total of 18 students completed both the pre-test and the post-test and their scores were included in the final data. Statistical analysis of the average scores using paired t-tests revealed no significant difference between the performance of the students in either group, indicating that the multimedia approach to learning endodontic problem solving may successfully replace traditional learning strategies.

Effective orthodontics: achieving objectives, avoiding misadventures.

The authors outline four principles that should be considered when planning orthodontic tooth movement. They suggest that dentists have clear treatment objectives, know the force requirements to achieve those objectives, choose the best equipment to provide the needed forces and prevent unwanted tooth movement during treatment. To illustrate use of these principles, the authors refer to a sample treatment scenario. They also provide a mnemonic device to help dentists recall these principles.

Subpontic hyperostosis.

Two cases of subpontic hyperostosis are presented. This condition is an intraoral bony exostosis that has been observed beneath a fixed partial denture. Subpontic hyperostosis seems to be associated exclusively with the posterior mandible, usually the first molar position. The first case occurred in a 64-yr-old Asian male and the second appeared bilaterally in a 79-yr-old female. It has not been described extensively in the literature, with only 33 cases having been reported previously. The etiology of this condition is unknown, with factors such as genetic predisposition, mechanical stress, and inflammation suggested as possible causes. Treatment of this hyperostosis is be surgical excision, and if necessary is usually due to the impingement of the growth on the pontic and the inability of the patient to maintain adequate oral hygiene in the area.

Opinions and experiences of dental students and faculty concerning computer-assisted learning.

This study assessed the opinions and attitudes of faculty and students concerning the use of computer-assisted learning (CAL) at three different dental schools on two continents (Manchester, U.K.; Nijmegen, The Netherlands; and Lexington, Kentucky, U.S.A.). In each school students and faculty received a questionnaire; faculty by internal mail, students at the end of a lecture. Response rates for students were 76 percent in Manchester, 64 percent in Nijmegen, and 91 percent in Lexington. The respective figures for faculty were: 42 percent, 47 percent, and 39 percent. In all three schools approximately 50 percent of students had a computer at home. Students in Lexington and Manchester seemed to be more advanced in the use of computers for self-instructional learning. Students and faculty in Lexington had more experience with interactive multimedia than did those in Manchester and Nijmegen. In general, Lexington students were somewhat more familiar with computers and CAL than Manchester students, with Nijmegen showing the lowest percentages. Few CAL programs were available at any school, with small numbers of dental students having been exposed to programs involving animation (vision, sound). The majority of students are of the opinion that the use of computers for learning is not impersonal, nor difficult, but challenging and motivating. There is good agreement that if a program is to be bought or developed, it should be a combination of text, images, and sound. It is postulated that concerted action by dental schools is required to realize the potential of CAL in dental education, and that international organizations should give consideration to coordinating this action.

A comparison of intracanal stresses in a post-restored tooth utilizing the finite element method.

The finite element method was used to compare stresses along the inner canal wall in four two-dimensional models of an average maxillary central incisor. The four models evaluated were an intact incisor, an endodontically treated incisor, an endodontically treated crown-restored incisor, and a cylindrical post and crown-restored incisor. A horizontal static force, 1 Newton in magnitude, was applied to the lingual surface of each model and the maximum tensile, compressive, and shear stresses were calculated using the general purpose finite element program PAFEC 75. Results indicate that the stress patterns within the root are altered as a result of post insertion. Specifically, the maximum bending stresses are associated with the apical termination of the post, and post placement does not result in a uniform distribution of stress along the canal wall.

In vitro tensile bond strengths of amalgam to treated dentin.

Since amalgam traditionally relies on undercuts in the tooth preparation for retention, extensive tooth structure must be removed for amalgam core build-ups. In contrast, the ideal build-up material would achieve its retention by directly bonding to tooth structure. This study compared tensile bond strengths of amalgam to dentin using All-Bond Liner-FX with three different dentin pretreatment conditions and Amalgambond according to the manufacturer's directions. One hundred and twenty dentin samples were tested. Groups 1-3 used All-Bond Liner-FX as a bonding agent. Group 1 received a 15-second application of 10 percent phosphoric acid on the dentin; Group 2 received the recommended dentin conditioner; and Group 3 received no dentin pretreatment. Group 4 used Amalgambond as the bonding agent after a 10-second application of 10 percent citric acid/3 percent ferric chloride. Analysis of the data was conducted using both ANOVA and the Weibull statistic. Results of the analysis of variance indicate that there were no statistical differences among mean tensile bond strengths for the three dentin pretreatment conditions using All-Bond. All (30) of the Amalgambond specimens debonded prior to testing. The All-Bond fracture data was well described by the Weibull function as evidenced by the high coefficient of determination (R2 = 0.98-0.99). Fracture analysis indicated that all of the Amalgambond failures were adhesive at the Amalgambond-amalgam interface. All-Bond fractures were mixed cohesive/adhesive failures indicating similar bonding to amalgam and dentin.

A comparative study of fluoride release from glass-ionomer cements.

This study compared the amounts and patterns of fluoride release from 11 commercially available glass-ionomer cements into artificial saliva over an 84-day period. The results indicated that the materials differed in the amount of fluoride released, and that Miracle Mix released the highest cumulative total of fluoride over the test period. Along with old Fuji II, Miracle Mix also released the most fluoride during the last time interval (56 to 84 days). All of the materials released the greatest proportion of their cumulative total fluoride in the first 24 hours after mixing.

Fluoride release from light-cured liners.

This study compared the relative amounts and patterns of fluoride release from six commercially available light-cured liners in artificial saliva over a 28-day period. Cavalite and two Zionomer products released relatively small amounts of fluoride. Timeline and XR Ionomer released the highest cumulative total of fluoride over time. During the last time interval (14-28 days), Timeline released the greatest amount of fluoride. Patterns of fluoride release for all materials were similar with the largest proportion of the total fluoride release being in the first 24-48 hours, followed by a dramatic reduction in release rate.

Using the electric pulp tester with gloves: a simplified approach.

A method is presented which simplifies the use of the electric pulp tester for the dentist who routinely wears gloves in practice. Advantages of this method include a reduction in patient apprehension as well as a possible decrease in discomfort for the patient.

Ketoprofen in dentistry: a pharmacologic review.

The pharmacology, clinical dental studies, and the relevance to dental applications of ketoprofen, a recent addition to the group of nonsteroidal anti-inflammatory drugs, are reviewed. In addition to inhibiting the formation of prostaglandins, ketoprofen may also suppress leukotrienes and further limit inflammation. Clinically, it appears that ketoprofen compares favorably with many of the nonsteroidal drugs now in use. Recently approved for use in mild to moderate pain, ketoprofen's rapid onset of action, patent analgesic properties, and minimal side effects are particularly appealing.