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At least 505 records · Page 28Linked to original sources
PubMed1996

Proof of efficacy of different modified sonic scaler inserts used for debridement in furcations--a dummy head trial.

The purpose of this study was to determine the suitability of different scaling instruments for surgical removal of hard and soft bacterial deposits and for the removal of soft accretions only for maintenance treatment within furcations. 12 upper and 12 lower plastic replicated molars, with through-and-through furcations, were instrumented 3 x with 4 different types of instruments: (1) hand instruments; (2) a conventional sonic scaler insert; (3) a set of 3 modified sonic scaler inserts with budded tips and different angulated shafts; (4) a set of 3 sonic scaler inserts with a plastic-coating and different angulated shafts. The plastic replicas were fixed in a dummy head without any replicated soft tissues. In the furcation area, an easily removable surface coating material was applied to the teeth to represent the "plaque" and a second, more stubborn lacquer layer representing "calculus/cementum". Following instrumentation, the following parameters were recorded to assess efficacy; time required for instrumentation, loss of weight, depth of substance removal at the furcation entrance, % of furcation area instrumented, whereby removal of these 2 layers was judged separately. Only minor differences were observed between hand instruments, conventional and budded sonic scaler inserts as to loss of weight, depth of substance loss and area instrumented. The plastic-coated sonic scaler inserts were just as effective in surface layer removal representing "plaque" as the 3 other instruments, but resulted in less loss of weight and less depth of substance removal. In conclusion, the more aggressive hand instruments, the conventional and budded sonic scaler insert, are preferably used for the surgical phase to increased ease of entry into the furcation dome. An effective debridement of the furcation roof seems only possible with an odontoplastic, for which a furcation is fitted to the instrument by means of an intensive instrumentation, thus leading to weight loss and pronounced substance removal. The plastic-coated sonic scaler inserts seems to be a reasonable choice for maintenance treatment within furcation, since this treatment phase is usually restricted to removal of soft bacterial deposits.

Analysis of Variance↗
PubMed1999

Building on our accomplishments.

BACKGROUND AND OVERVIEW: There are at least five forces--knowledge, finances, diversity, faculty and government--that have the potential to change the current model of dental education significantly in the new century. The author explores these forces and attempts to project their future impact on dental education and the profession. CONCLUSIONS: Our understanding of the etiology and pathogenesis of oral diseases will increase, though likely not enough to facilitate the elimination of either dental caries or adult-onset periodontitis. A mandatory year of additional formal education in the form of a postgraduate residency will become necessary. Current trends in the sources of revenue supporting dental education will continue, and dental education will face a financial crisis. The changing ethnic and racial diversity of the United States and the dental work force will require curricular changes to prepare students to meet the oral health needs of diverse populations. The current shortage of full-time dental faculty members will continue, and dental schools will need to redefine what it means to be a faculty member. Finally, the continuing decline in the dentist:population ratio and a peak in the actual number of active dentists will cause government to again question the adequacy of the dental work force. PRACTICE IMPLICATIONS: Academic dentistry faces a new century with new challenges, all of which have implications for current and future dental practitioners. The extent to which these challenges are successfully met will depend on the degree to which those with a vested interest in a thriving profession come together for the mutual benefit of all.

Cultural Diversity↗
PubMed2001

[Ct-assisted navigation for insertion of dental implants in maxilla models].

The use of CT-based intraoperative navigation has greatly improved controlled surgery in many specialties. In this study the precision of the SMN system (Zeiss, Oberkochen, Germany) for navigated drilling and following implantation in the maxilla is evaluated. This study should prove the suitability of navigation systems for computer-assisted implantation in the maxilla to avoid perforation to the maxillary sinus. Therefore 60 target drills were carried out on 10 standardized polyurethane milling models after CT-scanning. The models were produced with cranial open maxillary sinuses. The CT-scans were performed with a slice distance of 1 mm. Then the CT-data were transferred to the workstation of the SMN system (Zeiss, Oberkochen, Germany) and a referenciation of the fiducials for superposition of the native and CT model were done. Referenciation of the model was performed with the aid of a drilling tool. This drilling tool was used for later navigation-assisted drilling into the upper jaw. The target of drilling was the maxillary sinus floor. The aim was to come as near as possible without perforation. The distance of the bottom of the drilling holes to the maxillary sinus floor were measured after section of the model. An average drilling depth of 6.97 mm (s=0.4) and a mean distance to sinus floor of 0.11 mm (s=0.2) was found. In 13 cases the lower board of sinus was perforated.In conclusion a high precision of CT-based navigation for controlled preimplantological drilling was seen.

Dental Implantation↗
PubMed1982

A model culture system with human gingival fibroblasts for evaluating the cytotoxicity of dental materials.

A model experimental culture system and protocol are described to screen polymerized dental materials for diffusible toxic products. The system employs cultures of human gingival fibroblasts grown in plates containing immobilized samples of polymerized resins. Comparative cytoxicity is evaluated by counting viable cells with the aid of phase optics at several time periods up to 48 h. To achieve adequate statistical sampling, multiple counts are made in four different zones at 90 degrees angles from each sample and at three distances from the centers of samples. The most significant data were generated during a 24 to 48 h test period in climate. This cytotoxicity test measured cell death as a function of time of exposure and distance from the sample (24 h, 0 to 3 mm; 48 h, 3 to 6 mm) and permitted a calculation of the relative cytoxicity for each material, which is termed the viability index (VI). This can be expressed as a percentage related to the control, which is called the time-distance cytotoxicity index (TDCI). This method is simple to carry out because it used basic laboratory equipment, is rapid, and has a sound scientific basis. It focuses on times and distances when or where, or both, the greatest cellular changes are taking place. Some data illustrated are based on the screening of eight different restorative resins. The literature of cell culture testing of dental materials is reviewed. It is concluded that biotoxicity studies ideally should employ diploid human target cells from the oral cavity because the cells retain specialized features. Secondary cultures or strains of human diploid gingival fibroblasts, which are relatively easy to obtain and maintain, are recommended as cells of choice for screening dental restorative materials in vitro.

Adult↗