Correlation of radiographic analysis during initial planning and tactile perception during the placement of implants.

Most of the decisions made in planning treatment with implants rely on the clinician's assessment of the density of the jawbone. However, we know of only a few studies that have evaluated the clinicians' subjectivity and the objective quantitative methods. Our aim was to assess whether the characteristics of the bone seen on preoperative imaging are similar to the features faced during the operation. We collected data about 32 implant procedures done during the Specialisation Course for Implant Dentistry, Universidade de Ribeirão Preto, San Paulo. First, the clinicians evaluated the panoramic radiograph and computed tomographic scans preoperatively, classified the bone density according to the Lekholm and Zarb classification, and marked their subjective evaluation on a visual analogue scale. Postoperatively the surgeons filled out a questionnaire based on their subjective perceptions obtained during the insertion of the implants. Another examiner answered the same questionnaire after looking at the patient's images but without knowing the surgeon's results. There was a good correlation between the surgeons' preoperative classification of the type of bone and their tactile perception (p=0.000), and a good correlation between the surgeon's preoperative classification of the bone and the examiner's findings (p=0.000). We conclude that imaging is an important part of preoperative planning and can predict the quality of the bone when coupled with the opinion of a trained clinician, objective analysis, and standard classification of the bone.

Osteoconductivity of modified fluorcanasite glass-ceramics for bone tissue augmentation and repair.

Modified fluorcanasite glasses were fabricated by either altering the molar ratios of Na(2)O and CaO or by adding P(2)O(5) to the parent stoichiometric glass compositions. Glasses were converted to glass-ceramics by a controlled two-stage heat treatment process. Rods (2 mm x 4 mm) were produced using the conventional lost-wax casting technique. Osteoconductive 45S5 bioglass was used as a reference material. Biocompatibility and osteoconductivity were investigated by implantation into healing defects (2 mm) in the midshaft of rabbit femora. Tissue response was investigated using conventional histology and scanning electron microscopy. Histological and histomorphometric evaluation of specimens after 12 weeks implantation showed significantly more bone contact with the surface of 45S5 bioglass implants when compared with other test materials. When the bone contact for each material was compared between experimental time points, the Glass-Ceramic 2 (CaO rich) group showed significant difference (p = 0.027) at 4 weeks, but no direct contact at 12 weeks. Histology and backscattered electron photomicrographs showed that modified fluorcanasite glass-ceramic implants had greater osteoconductivity than the parent stoichiometric composition. Of the new materials, fluorcanasite glass-ceramic implants modified by the addition of P(2)O(5) showed the greatest stimulation of new mineralized bone tissue formation adjacent to the implants after 4 and 12 weeks implantation.