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Biomedical subjects

B Klinge

Publications and source records attributed to B Klinge.

At least 55 records · Page 3Linked to original sources

Visualisation of the mandibular canal by different radiographic techniques.

6 mandibles were radiographically examined bilaterally to visualise the mandibular canal. 5 imaging techniques were used: periapical radiography, panoramic radiography, hypocycloidal tomography, spiral tomography and computed tomography (CT). Panoramic radiographs were obtained with 2 different X-ray machines. The CT-examinations comprised direct images and standard reconstructions based on axial slices. The specimens were subsequently sectioned for contact radiography. The visibility of the mandibular canal was estimated by 3 observers at special reference points on all radiographs and classified as clearly visible, questionable visibility or not visible. The contact radiographs served as the "gold standard". The inter-observer and the intra-observer agreement were assessed by calculating the overall agreement and the x value. Direct coronal computed tomography, as well as spiral and hypocycloidal tomography, gave better visualisation of the mandibular canal than periapical and panoramic radiography.

Cadaver↗

Evaluation of different methods to clean titanium abutments. A scanning electron microscopic study.

The cleaning effectiveness of different treatment methods for titanium abutments was evaluated using scanning electron microscopy (SEM). In the mandible of 4 beagle dogs, 25 titanium abutments were installed (modum Brånemark). After 16 weeks of plaque accumulation, mineralized deposits had formed on 23 abutments. Each of these abutments was subjected to one of the following treatment methods: scaling with (1) metal, (2) plastic, or (3) ultrasonic instruments; (4) air-polishing, (5) weekly rubber cup polishing or (6) daily brushing with a conventional toothbrush. Fourteen abutments were removed immediately after treatment. On 9 abutments, the scaling procedures and air-polishing were repeated after another 16 weeks of plaque accumulation. The abutments were prepared for SEM, and each of them was viewed and photographed at 3 different magnifications. The photomicrographs were evaluated by 3 examiners who, guided by reference pictures, gave each abutment a "cleanliness" score, ranking from 0 to 5. Regular rubber cup polishing and regular brushing resulted in the highest surface cleanliness, while the air-polishing procedure showed the lowest cleanliness score. None of the 3 scaling methods created a cleanliness score better than 3. The 3 scaling methods were considered equal in their cleaning effectiveness. No differences could be observed between surfaces treated 1 x or 2 x. Taken the present findings and those of other studies concerning the effects of scaling on the surface roughness and biocompatibility into consideration, it was concluded that plastic scalers may be the instruments of choice for debridement of titanium implant surfaces.

Animals↗

The effect of topical metronidazole therapy on experimentally-induced periodontitis in the beagle dog.

The present study was performed to assess the effect of topical metronidazole therapy on ligature-induced periodontitis in beagle dogs. 6 beagle dogs with experimentally-induced periodontitis on the mandibular 2nd, 3rd and 4th premolars were treated with metronidazole 10% dental paste 2 x daily for 4 weeks in an open placebo-controlled study using a split-mouth design. Recordings of probing pocket depth, bleeding on probing and gingival index were performed before commencement of treatment and repeated weekly during the 4-weeks treatment period. Concurrently, samples for microbiological analysis were collected from 2 of the dogs. The results demonstrated that probing pocket depth, bleeding on probing and gingival index had improved significantly in the metronidazole-treated side compared with the placebo-treated side. Black pigmented Bacteroides spp. and Spirochetes, present in all samples before treatment, were eliminated from the metronidazole-treated side after the 1st week of treatment and throughout the treatment period, whereas they were present in all samples from the placebo-treated side. The result of the present study demonstrates that topical application of metronidazole in a dental paste, improves the clinical features of the experimentally-induced periodontitis and eliminates some of the micro-organisms associated with the disease.

Animals↗

3 regimens of topical metronidazole compared with subgingival scaling on periodontal pathology in adults.

This report presents the findings from an open randomized multicentre clinical trial designed to compare the clinical efficacy of scaling with application of 3 different preparations/dose frequencies of topical metronidazole in the treatment of adult periodontitis. The 4 treatments were: (A) metronidazole 25% dental gel administered 1 x a week for 2 weeks; (B) metronidazole 15% dental gel applied 1 x a week for 2 weeks; (C) metronidazole 15% dental gel applied 2 x a week for 2 weeks; (D) subgingival scaling, performed 1 x only. A split mouth design was used. Patients were included in the study if they had at least 1 tooth in each quadrant with a pocket depth > or = 5 mm in at least 1 of 4 sites. A total of 61 patients from 4 centres were entered into the study. The efficacy parameters were probing pocket depth and bleeding on probing. Follow-up visits for recording of clinical efficacy were made at 2, 4, 6 and 12 weeks after the end of metronidazole treatment. All 3 antibiotic treatments (A, B, C) reduced the symptoms of periodontal pathology and yielded results comparable to those seen after subgingival scaling (D). When using a topical drug therapy, it seems important to use a preparation that requires as few applications as possible. The best candidate for drug therapy would therefore be treatment (A) metronidazole 25% applied 1 x a week for 2 weeks.

Adult↗

Contribution of autogeneic membranous bone chips and bone paste to healing of rabbit skull defects.

In skeletal surgery, bone chips and bone paste are often used to facilitate bony repair. However, no comparative investigation between these forms of bone graft implantation has been undertaken. In this study four trephine skull defects were produced in each of 14 adult rabbits and inlays of bone paste and two separate amounts of bone chips were then implanted in each animal. The results were compared relative to a control defect and assessed by gross inspection, light microscopy, and contact radiography after periods of 4 and 15 wk. Bone chips offered only minor advantages over controls in the defects investigated and differences in bony regeneration between the diversified amounts of bone chips were negligible. After bone paste implantation, a cellular and mature bone was rapidly produced. The clinical significance of these findings is discussed.

Animals↗

Regenerative response to membranous and enchondral lyophilized allogeneic bone in rabbit skull defects.

The regenerative responses of inlays of lyophilized allogeneic bone of membranous (skull) and enchondral (tibia) origin were studied in an experimental cranioplasty model in rabbits. The lyophilized bone particles were also bioassayed for inductive bone production in an orthotopic critical size defect rat model. Three trephined calvarial defects were evaluated in each of 14 adult rabbits. The experimental materials were implanted into two of the defects and the third was left empty for control purposes. The implants disclosed no major structural divergences as assessed by scanning electron microscopy. Healing was evaluated by light microscopy and contact radiography after periods of four and 15 weeks. The lyophilized bone allografts of both embryonic origins displayed a similar fashion of bone regeneration, bone marrow reappearance, and volumetric density of trabecular bone substance and displayed no obvious differences between experimental groups or intervals. The two materials exhibited low osteoinductive potential.

Animals↗

Implants in relation to natural teeth.

Osseointegrated implants are now an accepted part of the prosthetic treatment of edentulous patients. More recently, osseointegrated implants have been advocated in the treatment of partially dentate patients. The implants can be used in conjunction with natural teeth for the support of rigid prostheses. The natural tooth is supported in bone by a periodontal ligament, whereas the implant may be described as having a more intimate or ankylotic connection with the supporting bone. Different attachment mechanisms may lead to differential rates of destruction in both situations, particularly if teeth and implants are splinted together by a rigid prosthetic appliance. Also noteworthy are the possible differential rates of marginal tissue breakdown as a result of the influence of bacteria. Results of a pilot study in which marginal breakdown was induced around implants and natural teeth in beagle dogs suggest that the process of destruction proceeds more slowly in the case of implants. However, the disease process around implants may be more difficult to arrest due to conjectural problems in treating the surface of the implant using conventional techniques of periodontal treatment. From the limited data available so far, it would appear that osseointegrated implants can be used as predictably in partially dentate as in totally edentulous mouths. More research should be initiated on the potential for tissue-breakdown, and long-term maintenance of the marginal tissues around implants.

Dental Implantation, Endosseous↗

A new experimental model for studies of local inflammatory reactions.

The aim of the present study was to develop and evaluate a method for studies of the early phase of the local inflammatory reaction, based on continuous diffusion of an inflammatory inducing agent. 25 rats were used. Four sterile teflon tablets were implanted subcutaneously in the back of each animal. After 3 weeks, when a connective tissue capsula had formed, the tablets were replaced by two test tablets, containing 35 micrograms lipopolysaccaride, one placebo and one teflon tablet. Five rats were sacrificed on day 0, 4, 7, 14, 21, respectively, and biopsies comprising tablet and surrounding tissue were harvested and exposed to routine histologic treatment. The number of leucocytes was assessed in four defined areas adjacent to each tablet. During the first seven days an increase in the number of leucocytes was seen in the tissues adjacent to test tablets. After 14 and 21 days the number of leucocytes was still high but lower as compared to day 7. In the tissues bordering the placebo and teflon tablets only few inflammatory cells were found. The results suggest that the tested method is suitable for studies of local inflammatory reactions during a 21 day period in experimental animals.

Animals↗

Regeneration of cranial suture and bone plate lesions in rabbits. Implications for positioning of osteotomies.

The positioning of osteotomies in intramembranous cranial bone was studied by exploring the pattern of bone regeneration in growth areas (the sutural region) as compared to that of the bone plate proper. Trephine defects in the left coronal suture area and the right parietal bone were produced in fifty-nine young rabbits. A pilot study to refine operative and analytical methods comprised 22 animals. The experiments were terminated at one, three, and six weeks after surgery. The bone regenerative response was assessed by x-ray planimetry, plain microscopy, enzyme histochemistry, and fluorescent labelling. Only minor divergences in healing capacity between the two defects were found. No adverse effects on the growth process were indicated. As to clinical management, the findings suggest that osteotomies designed to traverse sutural areas will, under normal circumstances, regenerate in a similar manner and rate to adjoining bone plates.

Acid Phosphatase↗

Clinical and histological findings in ligature-induced experimental periodontitis in dogs. A pilot study.

Prior to experimental periodontal regenerative procedures in animals, the process of destruction due to periodontitis is often simulated by placing ligatures around the necks of teeth. 2 models, one using cotton floss ligatures and the other elastic rubber ligatures, have been widely used. The aim of this study was to compare these 2 methods using clinical and histometric criteria. Premolars on both sides of the mandibular jaw were used in 2 beagle dogs. Periodontal tissue breakdown was induced during a 48-day period using cotton floss ligatures on one side of the mandible and contra-laterally by elastic rubber ligatures. At weekly intervals, the ligatures were changed and pocket depth and loss of probing attachment were recorded. All the ligatures were removed after 7 weeks. The animals were fed a soft, plaque-promoting diet during the experimental period. 20 days after ligature removal, the teeth were hemisected and the 2 roots extracted. From each tooth, 1 root was prepared for scanning electron microscopy and one for light microscopy. At the time of extraction, no differences regarding pocket depth or probing attachment level were found between the 2 groups. Root resorption was observed in all elastic ligature teeth, whereas only minor alterations at the root surface were observed on cotton ligature teeth. This finding may be of particular interest to investigators designing studies evaluating the healing sequalae of regenerative surgery in animals. As was observed in this study, root resorption can already be present in the pre-experimental phase of periodontal tissue breakdown, particularly if elastic ligatures are used.

Animals↗

Topical fluconazole for experimental candida keratitis in rabbits.

Using a reproducible model of Candida albicans keratitis in rabbits we studied the effect of topical fluconazole, a new triazole. Candida albicans DSM 70010 (2.5 X 10(5) cells) was injected into the corneal stroma of both eyes of 21 rabbits. All eyes developed a corneal ulcer. Forty-eight hours after inoculation the animals were divided into three groups: (1) 14 eyes, received fluconazole (2 mg/ml) and the epithelium subsequently removed; (2) 14 eyes, received only fluconazole drops; (3) 14 eyes, received 0.9% NaCl: half of this group was also debrided. We applied one drop of either substance 10 times a day for 24 days. A further six rabbits were used to judge if the drug penetrated into the cornea and aqueous humour. There was a highly significant difference between the fluconazole groups (1,2) and the control group (3) as to hypopyon and complications (descemetocele, corneal perforation) as well as recultivation of C. albicans from corneal tissue. The difference between the fluconazole groups with and without debridement was not significant. The drug penetrated into the cornea and aqueous humour of both uninflamed and inflamed eyes.

Administration, Topical↗

Periodontal bone loss in the aging beagle dog. A radiographic study.

Studies in the beagle dog have clearly established the usefulness of this breed in periodontal disease research. However, little is known about the progressive nature of the disease with advancing age. It is the purpose of this paper to describe frequency and distribution of radiographically detectable lesions in an aging population of 166 colony dogs. 3 grades of alveolar bone loss were determined on high-quality postmortem radiographs. The number of teeth involved was similar in male and female and was age-dependent. Disease was more frequent in the maxillary arcades, with the 2nd upper premolar most frequently involved. Most extensive bone loss was noted around the 3rd and 4th upper premolars, and 1st and 2nd lower molars. It is felt that by the study of such a large group of older colony dogs, a better understanding can be gained of the expected alveolar bone loss with age as determined radiographically.

Aging↗

[Natamycin (pimaricin) in the treatment of experimental keratomycosis].

The efficacy of natamycin (pimaricin) was studied and compared with the standard amphotericin B, using a reproducible model of keratomycosis from Candida albicans in the rabbit. C. albicans DSM 70010 (2.5 X 10(5) cells) was injected into the corneal stroma of both eyes. All eyes developed a corneal ulcer without pretreatment with immunosuppressive agents. Forty-eight hours after inoculation, the animals were divided into five groups: I (10 eyes) and II (12 eyes) receiving natamycin drops, 1%; groups III (12 eyes) and IV (12 eyes) receiving natamycin, 2.5%; the control group (14 eyes) receiving 0.9% NaCl. For better penetration of the drug, the epithelium of groups I and III was removed every 3rd day. Half of the control group was debrided as well. In a further series, the penetration of natamycin into the cornea and aqueous humor was studied. There was no difference between the treated eyes and the control eyes concerning complications (descemetocele or perforation). It is concluded that natamycin (pimaricin) is inferior to amphotericin B and not effective in controlling experimental keratomycosis.

Animals↗

Effect of tetracycline and SnF2 on root resorption in replanted incisors in dogs.

The present study was made to assess the effect of applying SnF2, tetracycline, or both, to root surfaces of extracted teeth prior to replantation. In five young adult beagles, a total of 18 mandibular incisors were extracted, bench dried for 45 min, and reimplanted in their respective sockets either after no further treatment or following treatment with 1% doxycycline HCl for 5 min, 1% SnF2 for 5 min, or 1% SnF2 followed by 1% doxycycline HCl. After 4 wk of healing, the relative frequency of root resorption (surface resorption, inflammatory resorption and replacement resorption) was approximately 27% of the root surface in bench-dried as well as in doxycycline-treated specimens. By contrast, SnF2-treated and SnF2 + doxycycline-treated teeth showed less than 1% resorption. In the latter two specimen groups an inflammatory reaction in the periodontal ligament without resorption occurred with a frequency of 38.3% and 11.1%, respectively. The results indicate that application of SnF2 to the root surface prior to replantation effectively reduces resorptive processes during the first postoperative weeks. By subsequently treating the root surface with tetracycline, the adverse effect of SnF2 on periodontal connective tissue repair may be reduced.

Animals↗

Management of craniotomy in young rabbits.

A safe and easy-to-manage technique for various craniotomy procedures in young rabbits has been developed. This technique, which minimizes the need for special instrumentation, has been tested in 90 animals with a minimal mortality and morbidity: one death perioperatively caused by sagittal sinus bleeding and one rabbit disclosing a brief period of postoperative illness, respectively. The technique, including postsurgical strategy, is described in detail.

Animal Welfare↗

In vivo uptake and retention of fluoride after a brief application of TiF4 to dentin.

The purpose of this study was to examine the long-term retention of F and Ti in dentin after a brief application of 1% TiF4. Six facets of exposed dentin in each of four beagle dogs were treated for 10 sec or 1 min with a 1% solution of TiF4. Four control facets in a fifth dog were left untreated and extracted after 12 weeks. The TiF4-treated teeth were harvested after 4, 8, and 22 weeks and analyzed for F and Ti with an electron microprobe. The F concentrations in dentin surfaces of specimens retained in the mouth for 4, 8, and 22 weeks were after the 10-sec treatment 0.48% +/- 0.24, 0.51% +/- 0.20, and 0.56% +/- 0.20, respectively, and after the 1-min treatment 0.64% +/- 0.20, 0.66% +/- 0.18, and 0.71% +/- 0.19. High concentrations of Ti were found at the specimen surfaces in all groups. None of the control specimens showed F or Ti contents above the detection limits for the method used. The results showed that a very brief application of 1% TiF4 deposited high concentrations of F and Ti which were retained for at least 22 weeks.

Administration, Topical↗