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Biomedical subjects

D Buser

Publications and source records attributed to D Buser.

At least 91 records · Page 5Linked to original sources
PubMed1991

Digital subtraction radiography for the assessment of changes in peri-implant bone density.

Digital subtraction radiography is proposed as a potential diagnostic tool for implant research and patient monitoring. Examples of the application of this technique are given observing peri-implant density changes during the early healing phase and during ligature-induced peri-implantitis in an animal model. Additional cases document the loss of peri-implant bone density associated with an infection and increase in density caused by remodeling after functional loading of an implant with a single crown. Digital subtraction radiography might be one of the most sensitive noninvasive methods for assessing subtle density changes in peri-implant tissues, providing additional diagnostic information on implant tissue integration and maintenance.

Alveolar Bone Loss↗
PubMed1991

Tissue integration of one-stage ITI implants: 3-year results of a longitudinal study with Hollow-Cylinder and Hollow-Screw implants.

This study examined the tissue integration of one-stage, nonsubmerged ITI implants over a period of 3 years. Fifty-four implants were placed in 38 partially edentulous patients. Following healing (at least 3 months), all 54 implants were free of peri-implant infections and revealed no detectable mobility. Radiographs showed no signs of peri-implant radiolucencies, and the implants were in favorable positions for prosthetic restoration. Following incorporation of fixed partial dentures, patients were enrolled in a hygiene recall program with 3-month intervals and were examined once a year. Based on predefined criteria, each implant was classified as successful or failing. After the 3-year observation period, 51 of 53 implants (96.2%) were considered successfully integrated. (One patient with one implant dropped out of the study.) Two implants exhibited recurrent peri-implant infections and were classified as late failures. These results indicate that one-stage ITI implants can achieve successful tissue integration on a predictable basis and that it can be maintained over a period of at least 3 years.

Dental Implants↗
PubMed1990

Regeneration and enlargement of jaw bone using guided tissue regeneration.

The purpose of this study was to present the surgical procedures and the clinical results of guided tissue regeneration (GTR) treatment aimed at regenerating local jaw bone in situations where the anatomy of the ridge did not allow the placement of dental implants. 12 patients were selected for ridge enlargement or bony defect regeneration. A combined split- and full-thickness flap was raised in areas designated for subsequent implant placement. Following perforation of the cortical bone to create a bleeding bone surface, a PTFE membrane was adjusted to the surgical site in such a way that a secluded space was created between the membrane and the subjacent bone surface in order to increase the width of the ridge or to regenerate bony defects present. Complete tension-free closure of the soft tissue flap was emphasized. Following a healing period of 6 to 10 months, reopening procedures were performed and the gain of bone dimension was assessed. In 9 patients with 12 potential implant sites, a sufficient bone volume was obtained to allow subsequent implant placement. The gain of new bone formation varied between 1.5 and 5.5 mm. In 3 patients, acute infections developed which necessitated early removal of the membranes and no bone regeneration could be achieved. The results of the study indicate that the biological principle of GTR is highly predictable for ridge enlargement or defect regeneration under the prerequisite of a complication-free healing.

Adolescent↗
PubMed1990

Tissue integration of non-submerged implants. 1-year results of a prospective study with 100 ITI hollow-cylinder and hollow-screw implants.

It has been postulated that the wound healing in a closed submerged location is one of the prerequisites for osseointegration of dental implants. The purpose of the present study was to evaluate the tissue integration of intentionally non-submerged titanium implants inserted by a one-stage surgical procedure. 100 ITI implants were consecutively placed in 70 partially edentulous patients. After a healing period free of masticatory loading for at least 3 months, the implants were examined. The clinical status showed for all implants neither detectable mobility nor signs of a peri-implant infection. Therefore, prosthetic abutments were inserted, and the patients were restored with fixed partial dentures. All patients were regularly recalled at 3-month intervals, and no patient dropped out of the study. Thus, all 100 implants were re-evaluated 12 months following implantation. Plaque- and sulcus bleeding indices, probing depth, clinical attachment level, width of keratinized mucosa, and periotest scores were assessed. In addition, standardized radiographs were analyzed for the presence of peri-implant radiolucencies and for the location of alveolar bone levels around the implants. Based on predefined criteria, the implants were classified as successful or failing. 98 implants were considered successful, and 1 implant failing. The remaining implant exhibited a peri-implant infection requiring local and systemic antimicrobial treatment. The results of this short-term study indicate that intentionally non-submerged ITI implants yield a high predictability for successful tissue integration.

Dental Implants↗
PubMed1990

Suspected periodontopathogens in erupting third molar sites of periodontally healthy individuals.

29 periodontally healthy subjects (11 female and 18 male) with a mean age of 24 years (range 19 to 38 years) and with partially erupted lower third molars participated in this study. 18 subjects demonstrated no signs or symptoms of acute inflammation and were without pain (group A). 5 subjects showed redness of the pericoronal tissues and experienced pain upon palpation (group B). 6 subjects suffered from acute pain and exhibited formation of pus (group C). Microbiological samples were taken from the lateral aspect of the pericoronal space using the paperpoint-method. Continuous anaerobic techniques were utilized for microbiological processing. The samples were cultivated on ETSA and on selective media and were studied by darkfield microscopy. Gram-negative anaerobic rods accounted for 27% (group A), 34% (group B) and 39% (group C) of all organisms growing on ETSA. Bacteroides intermedius was detected in 61% (group A), 80% (group B) and 83% (group C) of the samples. B. gingivalis was found in 1 sample of group A only. Fusobacterium sp. was detected in 56% (group A), 80% (group B) and 33% (group C) of the samples. Capnocytophaga were seen in 67% (group A), 20% (group B) and 50% of the samples. Actinobacillus actinomycetemcomitans was found in 44% (group A), 40% (group B) and 17% (group C). 72% of the group A and 100% of the group B and C samples contained spirochetes. In all of those positive samples, small spirochetes were present, but only 78% contained medium and only 48% large spirochetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Formation of a periodontal ligament around titanium implants.

The aim of this study was to examine wound healing events around titanium implants in the presence of retained root tips whose periodontium could serve as a source for cells which could participate in the healing process. Hollow cylinder implants with a titanium plasma-sprayed surface were placed in the mandible of monkeys where the apical portions of previously removed teeth were retained. After a healing period of 12 months, free of functional loading, the implants with surrounding tissues were removed and specimens analyzed in undecalcified sections. This report describes histologic findings of six such implants. Microscopic analysis revealed that in regions where implants were close to retained roots, a periodontal ligament had formed around large portions of the implant. Furthermore, there was a distinct layer of cementum on the implant surface and a periodontal ligament with collagen fibers perpendicularly oriented to the implant surface, implanted into the cementum on the implant surface as well as to the opposing bone. This initial observation suggests that it may be possible to achieve an anchorage of certain dental implants with a periodontium simulating that found surrounding the normal tooth. Furthermore, these findings provide the basis for further studies on regeneration of all components of the periodontal attachment apparatus including cementum, periodontal ligament, and bone.

Animals↗
PubMed1990

Titanium implants with a true periodontal ligament: an alternative to osseointegrated implants?

The purpose of the present study was to experimentally determine if cementum formation with inserting collagen fibers can be accomplished on dental implants. Titanium implants were placed in the mandible of monkeys, where apical root portions were retained. The histologic examination of undecalcified sections revealed that a cementum layer on the implant surface with inserting collagen fibers was achieved around implants placed in close relationship to retained roots; however, implants without contact to retained roots demonstrated the typical findings of osseointegration. These results demonstrate that dental implants with a true periodontal ligament can be accomplished.

Animals↗
PubMed1990

The treatment of partially edentulous patients with ITI hollow-screw implants: presurgical evaluation and surgical procedures.

The ITI hollow-screw implant is part of the new ITI Bonefit concept, which is based on more than 10 years of clinical experience with former ITI implants. Among other properties, ITI implants are characterized by a one-stage surgical procedure. This article describes the presurgical evaluation and surgical procedures for the treatment of partially edentulous patients with ITI hollow-screw implants. Of 111 implants placed, 110 revealed a complication-free tissue integration and one failed. These results demonstrate that one-stage ITI hollow-screw implants have a high predictability for successful tissue integration.

Adult↗
PubMed1990

Bone regeneration adjacent to titanium dental implants using guided tissue regeneration: a report of two cases.

The biologic principle of guided tissue regeneration was applied to regenerate alveolar bone in conjunction with the placement of titanium dental implants. In one case, complete osseointegration of an implant was achieved by the placement of a Teflon membrane over an implant that had been inserted into an alveolus immediately following tooth extraction. In a second case, the same biologic principle was used to increase the volume (height and width) of a resorbed, edentulous alveolar ridge to provide adequate bone dimensions for implant installation. In both cases, the membranes appear to have prevented the repopulation of the wound area by cells other than those derived from surrounding bone tissue. These two different applications of the principle of guided tissue regeneration open new avenues for reconstructive osseous surgery.

Adult↗