Comparison between planned prosthetic trajectory and residual bone trajectory using surgical guides and tomography--a pilot study.

Implant treatment is a highly technical and complex form of dentistry. Research and experience have shown that the success of dental implant treatment relies on a well-developed treatment plan approach that takes into account factors such as systemic condition, anatomical landmarks, occlusion, shape and density of the jawbone, and type of implant system. Historically, once the tissue was reflected, implant placement was guided by residual bone height and width, using the trajectory that was compatible with the location and direction of available bone, at times compromising prosthetic needs. The purpose of this study was to measure the amount of deviation between planned prosthetic trajectory (PPT), perpendicular to the plane of occlusion, and residual bone trajectory (RBT) in different areas of the maxillary and mandibular dental arches, using tomography in conjunction with surgical guides. Twenty-five patients with a total of 66 implant sites were selected for this study. A surgical guide with a radiopaque indicator was constructed to determine the PPT. Cross-sectional tomograms were taken through the indicator at each implant site. The outlines of the available bone, PPT and RBT, were traced, and the difference in the angulation between the two trajectories was determined. Results showed discrepancies between the PPT and the RBT to be greater in the mandibular molar areas. Further study of such pre-implant diagnostic procedures is needed to understand the relation between the PPT and RBT, thus increasing the predictability of implant success.

Surgical templates for prosthetically guided implant placement.

The article describes a prosthetically guided method for the fabrication of surgical templates for partially edentulous patients. A number of stainless steel components are used to capture the optimal prosthetic position for the placement of the implant determined from a diagnostic arrangement. A radiopaque stainless steel guide sleeve is used to guide the drill in preparation of the osteotomy after radiographs are made to verify the position and proposed trajectory of the guide sleeve.

Oral and esophageal Candida albicans infection in hyposalivatory rats.

The opportunistic fungus Candida albicans is a major cause of oral and esophageal infections in immuno-compromised patients, individuals on drug therapy, and the chronically ill. Because it has been observed that persons suffering from hyposalivation have an increased prevalence of oral candididiasis, we developed an animal model of infection based on hyposalivation. The objectives of our studies were to understand the mechanisms by which C. albicans causes oral disease and to begin to elucidate the role played by saliva in controlling C. albicans in the oral cavity. Our results showed that (i) oral Candida infection was established by a small challenge inoculum, (ii) mucosal lesions developed in the oral cavities and esophagi of infected rats, and (iii) transmission of oral Candida infection from an inoculated rat to uninoculated cagemates occurred rapidly. In addition, we compared the abilities of a clinical isolate and a spontaneously derived morphological mutant from that isolate to infect hyposalivatory rats and to induce disease. Infection was induced by the morphological mutant in hyposalivatory rats; however, the morphological mutant took significantly longer to transmit oral infection to uninoculated cagemates than did the parental strain.

Fabrication of imaging and surgical guides for dental implants.

Research and experience have suggested that the success of dental implants depends on a well-developed and careful treatment plan approach. Historically, implant size and angulation were determined with the use of panoramic radiographs and clinical judgment during surgery. This occasionally resulted in mechanical and esthetic compromise. This article describes the step-by-step fabrication process for 4 different imaging and surgical guides. Set-up disks, which enhance the design and fabrication of guides, also are introduced. These guides are used in conjunction with cross-sectional tomography during the preimplant assessment of surgical sites.

Long-term periodontal status after orthodontic treatment.

This study evaluated the clinical periodontal status of persons who had completed orthodontic therapy at least 10 years previously (study) and compared the findings to those of adults with untreated malocclusions (control). Subjects in the study (n = 112; 63 female subjects, 49 male subjects; mean age 29.3 +/- 4.2 [SD] years) and control (n = 111; 62 female subjects, 49 male subjects; mean age 32.9 +/- 6.5 years) populations underwent a comprehensive periodontal examination that consisted of measurements taken at six points around the circumference of each tooth: (1) plaque, (2) visual inflammation, (3) bleeding after probing, (4) pocket depth, (5) gingival recession, and (6) loss of connective tissue attachment. Data from the individual measuring points were organized into 14 different combinations of either tooth types or surface locations; each was subjected to a four-way ANOVA partitioned on group (study vs. control), sex, socioeconomic status, and malocclusion type. The results showed that differences in age distribution within the groups were affecting the comparisons between the groups. Consequently, the groups were balanced for age and analyses were done to investigate group differences by means of multiple regression techniques. The comparisons showed no significant differences between the groups for any of the periodontal variables. It was concluded that orthodontic treatment during adolescence had no discernible effect upon later periodontal health.