The classification of some oral streptococci of human or rat origin

An Adansonian classification of streptococci, many of which were oral in origin, was undertaken. The streptococci tested included both known cariogenic-, or non-cariogenic, strains and new oral isolates. Computation of the data was achieved by two techniques, (i) a comparison of overall similarity values, (ii) detection of nonrandom distribution of attributes. It appears that the oral streptococcal flora includes the well-defined species Strep. mutans, and the considerably more heterogeneous Strep. mitis, Strep. salivarius and Strep. sanguis, with considerable overlap between the last three species. The viridans group were quite distinct from the enterococci but less well separated from the “pyogenic” group of streptococci.     

Harvesting of bone from the iliac crest--comparison of the anterior and posterior sites

In 1998 we harvested a total of 127 bone grafts from the iliac crest of 65 male and 53 female patients aged 8-80 years. We measured the quantity of bone obtained, the operating time and the donor site morbidity of the anterior approach (n=81) compared with the posterior approach (n=46). The mean volume of bone harvested was 15 cm(3) (range: 9-25.5) of monocorticocancellous- or bicortico-cancellous bone chips or those from a trephine bur. The mean operating time for the anterior approach was 35 min (range: 22-48), for the posterior approach 40 min (range: 32-55). There were 15 complications, which were limited to those in whom the volume of bone exceeded 17 cm(3). The posterior approach caused less morbidity, notably in the form of significantly less pain and irregularity of gait. The patient has, however, to be repositioned during operation, which added to its total duration.     

Predoctoral implant dentistry curriculum survey: European dental schools

PURPOSE: In 2002 a survey of European dental schools was conducted. The purpose of the survey was to determine the curricular structure, teaching philosophies and materials used in predoctoral implant dentistry courses. MATERIALS AND METHODS: Fifty-six European dental schools were randomly selected from the Association for Dental Education in Europe representing 33 countries. A questionnaire was mailed to the predoctoral implant dentistry director/chairperson of the selected European dental schools. Of these, 40 schools returned the completed survey, resulting in a response rate of 71%. The mean, median and range of responses were computed where applicable. RESULTS: The results from this survey show that 80% of the responding schools required a course in implant dentistry. Between 1997 and 1999 over a third of responding schools (36%) incorporated a predoctoral implant dentistry course into their curriculum. Eighty-seven per cent of the schools have some prosthodontists teaching the course. Thirty-seven per cent of schools are offering a laboratory course in conjunction with the implant course. Sixty-three per cent of the schools are not restoring implant cases at the predoctoral level. However, 68% of schools reported students are required to be present during implant surgery. Ten per cent of schools require that the implant-related laboratory work be completed by the students. CONCLUSIONS: Predoctoral implant dentistry educational programmes vary from school to school. Yet a large percentage of schools agree on certain topics, including the importance of including implant education in predoctoral dental programmes.     

Fracture process characterization of fiber-reinforced dental composites evaluated by optical coherence tomography, SEM and optical microscopy

This study used optical coherence tomography (OCT) compared to scanning electron microscopy (SEM) and optical microscopy (OM) to evaluate qualitatively crack propagation and final fracture in restorative composite materials - Filtek Z250 and Filtek Z350 (3M ESPE) - with fiber reinforcement after cyclic loading. Samples were made using a split mold. Initially, 3-point bending tests were performed to determine the maximum force and tension at the fracture moment using samples without fiber reinforcement. Then, mechanical cycling tests were performed using samples with glass fiber embedded internally. The failures were analyzed using the 3 methods described before. OCT permitted good characterization of internal crack propagation of the dental composites, which, however, could not be visualized by either SEM or OM. OCT was proven to be laboratory research tool that is easy to use, does not require any specific preparation of the samples, and is less expensive than SEM.