Biomedical subjects

Asa Leonhardt

Publications and source records attributed to Asa Leonhardt.

3 recordsLinked to original sources

PubMed2003

Microbiologic diagnostics at titanium implants.

BACKGROUND: The microbiota found at periimplant lesions have been shown to contain putative periodontal pathogens as well as opportunistic species such as Staphylococcus spp, enterics, and Candida spp. Therefore, a microbiologic diagnosis may be of value as guidance before treatment of such lesions. PURPOSE: The aim of this study was to evaluate the prevalence of some putative pathogens associated with long-term followed-up cases using two different microbiologic procedures. MATERIALS AND METHODS: Fifteen subjects contributed with plaque samples from teeth and implants; these were analyzed with respect to 18 putative periimplant pathogens using cultural methods and a deoxyribonucleic acid DNA-DNA hybridization technique. RESULTS: The number of individuals positive for the analyzed pathogens was similar in samples taken from teeth and implants when analyzed with the DNA-DNA hybridization technique. When comparing detection frequency by culture procedure and by "checkerboard" technique at implants, the number of individuals positive for these species was lower with the traditional culture technique than with the checkerboard analyses. Using a higher cutoff point (> or = 4) with the checkerboard technique, the number of positive individuals was generally lower than that found with the culture technique. When comparing the techniques on an implant site level, the prevalence obtained by culture was lower for all analyzed species. If the specific species were present in the samples analyzed by the checkerboard technique, they were present only in every second sample analyzed with the culture technique. The high specificity values showed that if the checkerboard technique did not detect any Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetemcomitans, or Fusobacterium nucleatum, the bacteria were also undetectable by the culture technique. The two methods therefore did not overlap but did supplement each other. CONCLUSIONS: Based on the current results it is recommended that the technique used when analyzing microbiota around titanium implants should be a combination of the two protocols mentioned as they seem to give the most comprehensive outcome when used together.

Adult↗

PubMed2003

Five-year clinical, microbiological, and radiological outcome following treatment of peri-implantitis in man.

BACKGROUND: The aim of this study was to evaluate the long-term outcome of a combined surgical and antimicrobial treatment of peri-implantitis lesions in humans. METHODS: Nine partially dentate individuals with titanium implants demonstrating a marginal bone loss of > or = three threads as compared to baseline measurements made from 1-year intra-oral radiographs, bleeding on probing, and/or suppuration from the peri-implant sulci were included in the study. In each individual, subgingival bacterial samples were obtained and subjected to microbiological analysis by culture. Surgical exposure of the lesions and cleaning of the implants using hydrogen peroxide were performed. The patients were given systemic antibiotics according to a susceptibility test of target bacteria. The treatment was evaluated clinically, microbiologically, and radiograpically at 6 months, 1 year, and 5 years. RESULTS: Seven out of 26 implants with peri-implantitis at baseline were lost during the 5-year follow-up period despite a significant reduction in the presence of plaque and gingival bleeding. Four implants continued to lose bone, 9 had an unchanged bone level, and 6 gained bone. Five of the patients were treated with antibiotics directed against putative periodontopathogens, i.e., A. actinomycetemcomitans, P. intermedia, or P. gingivalis; three patients were treated for presence of enterics (E. coli and E. cloace); and, in one patient, treatment was directed against S. aureus. CONCLUSIONS: Despite treatment and retreatment, seven implants were lost. However, the applied surgical and antimicrobial treatment strategy for advanced peri-implantitis lesions was successful in 58% of the implants treated during the 5-year follow-up period. Smoking seemed to be a negative risk factor for treatment success.

Aged↗

PubMed2002

Long-term follow-up of osseointegrated titanium implants using clinical, radiographic and microbiological parameters.

The aim of this study was to longitudinally follow up osseointegrated titanium implants in partially dentate patients by clinical, radiographic and microbiological parameters in order to evaluate possible changes in the peri-implant health over time. Fifteen individuals treated with titanium implants, ad modum Brånemark, and followed for ten years were included in the study. Before implant placement ten years previously, the individuals had been treated for advanced periodontal disease and thereafter been included in a maintenance care program. The survival rate of the implants after ten years was 94.7%. The bone loss was 1.7 mm when using the abutment-fixture junction as a reference point. Of the individuals, 50% were positive for plaque at the implants. Bleeding on sulcus probing was present at 61% of the implant surfaces. Ten years previously, the individuals had been carriers of putative periodontal pathogens, such as Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetemcomitans, Capnocytophaga spp. and Campylobacter rectus, and were also carriers of these species at the current examination. The results of the present study suggest that the presence of these putative periodontal pathogens at implants may not be associated with an impaired implant treatment. These species are most likely part of the normal resident microbiota of most individuals and may therefore be found at random at both stable and progressing peri-implant sites.

Adult↗