Biomedical subjects
Publications and source records attributed to Kenneth G Boberick.
A case history is presented of a patient who fabricated 3 prostheses from autopolymerizing acrylic resin intended for fingernail augmentation and then cemented them into her mouth with super glue. Patients must be warned not to attempt self-treatment for esthetics with self-fabricated prostheses because severe adverse and irreversible hard and soft tissue reactions may occur.
Dental students achieved a high identification rate for darker shades (P14 and P24) on the Portrait IPN shade guide, which represent the highest chroma and lowest value in the grayish and reddish yellow hue groups. A high identification rate was also obtained for P32, representing the lowest chroma and highest value in the reddish gray hue group. The data suggest that dental students had the most difficulty determining the correct hue group for unmarked shade tabs. Incorrect responses tended to remain in the same value and chroma range but were selected in a different hue group.
Masticatory forces cause fatigue to cement-retained crowns and abutments and may adversely effect retention. The relation between the number of load cycles and the retentive forces is important. This study evaluated the effect of compressive cyclic loading on the retentive forces of a temporary cement used to retain implant crowns and the relationship between load cycles and retentive forces. Ten castings and implant abutments were cemented with zinc oxide-eugenol temporary cement. The retentive force necessary to dislodge the casting from the abutment was determined before and after the application of 2 Hz of vertical off-axis 3-mm sinusoidal-type compressive cyclic loading between 20 and 130 N for 500000, 1000000, and 5000000 cycles. These forces were equivalent to approximately 6 months, 1 year, and 5 years of human mastication. Data before and after the applied loading were analyzed with a paired sample t test (alpha = 0.05). The retentive forces of the 3 groups were analyzed by 1-way analysis of variance and post hoc by Scheffé multiple comparison (alpha = 0.05). The relation of the loading and the altered retentive forces were analyzed with the Pearson correlation coefficient. Compressive cyclic loading reduced the retentive forces significantly in all groups (P = .000). The retentive forces were reduced 16.75%, 18.73%, and 19.68% during the applied loading cycles of 500000, 1000000, and 5000000. All reduced retentive forces were not significantly different (P = .792). Although cyclic loading reduced the retentive forces, the increased cycles had little relationship (R = 0.119) to the decreased retentive forces of the temporary cement. The relationship between occlusal loading and retentive force can influence the choice of a temporary cement for a particular clinical situation.
An interim denture technique is presented describing the fabrication of an esthetic prosthesis that is used for short periods of time. The prosthesis conditions the patient for the acceptance of an artificial substitute for missing natural teeth until more definitive prosthodontic therapy can be provided. All the teeth in the arch are extracted simultaneously, and the interim prosthesis is inserted immediately thereafter. The prosthesis duplicates the morphology, color, and position of the extracted teeth. This technique satisfies a great need of socially and business-active patients because there is no interruption in their activities and no change in facial esthetics. Two case histories are presented.
This article describes the development, use, and student response to an online manual developed with off-the-shelf software and made available using a web-based course management system (Blackboard) that was used to transform a freshman restorative preclinical technique course from a lecture-only course into an interactive web-enhanced course. The goals of the project were to develop and implement a web-enhanced interactive learning experience in a preclinical restorative technique course and shift preclinical education from a teacher-centered experience to a student-driven experience. The project was evaluated using an anonymous post-course survey (95 percent response rate) of 123 freshman students that assessed enabling (technical support and access to the technology), process (the actual experience and usability), and outcome criteria (acquisition and successful use of the knowledge gained and skills learned) of the online manual. Students responded favorably to sections called "slide galleries" where ideal and non-ideal examples of projects could be viewed. Causes, solutions, and preventive measures were provided for the errors shown. Sections called "slide series" provided cookbook directions allowing for self-paced and student-directed learning. Virtually all of the students, 99 percent, found the quality of the streaming videos adequate to excellent. Regarding Internet connections and video viewing, 65 percent of students successfully viewed the videos from a remote site; cable connections were the most reliable, dial-up connections were inadequate, and DSL connections were variable. Seventy-three percent of the students felt the videos were an effective substitute for in-class demonstrations. Students preferred video with sound over video with subtitles and preferred short video clips embedded in the text over compilation videos. The results showed it is possible to develop and implement web-enhanced and interactive dental education in a preclinical restorative technique course that successfully delivered information beyond the textual format.
One of the most serious and prevalent problems associated with the restorative aspect of dental implants is loosening and fracturing of screws. Implant screws should be retightened 10 minutes after the initial torque application as a routine clinical procedure to help compensate for the settling effect. Mechanical torque gauges should be used instead of hand drivers to ensure consistent tightening of implant components to torque values recommended by implant manufacturers.
The purpose of this study was to determine whether varying the preload on the implant-abutment complex would affect screw loosening under simulated loading conditions. Abutment screws in sample models were tightened to 25, 30, 35, and 40 N-cm. One group of samples was allowed to stand for 3 hours after being torqued and then loosened. Another group of samples was retorqued after 10 minutes with the same initial torque value and then allowed to stand for 3 hours before loosening. For the load group of samples, the abutments were torqued into place, retorqued after 10 minutes, and a load applied for 3 hours before loosening. Cyclic loading was carried out using a servo-hydraulic testing machine with the values cycled between 1 and 26 pounds and the load applied directly to the abutments. Analysis of variance, analysis of covariance, and linear regression analysis was performed. Within the parameters of this in vitro investigation, the following recommendations can be made: (1) retightening abutment screws 10 minutes after the initial torque applications should be routinely performed and (2) increasing the torque value for abutment screws above 30 N-cm can be beneficial for abutment-implant stability and to decrease screw loosening.