Biomedical subjects

B Klinge

Publications and source records attributed to B Klinge.

At least 37 records · Page 2Linked to original sources

PubMed1996

Effect of local application of delmopinol hydrochloride on developing and early established supragingival plaque in humans.

The aim of the study was to investigate the effect of delmopinol hydrochloride on the development of dental plaque and on newly established plaque. In addition, the influence of this compound on the composition of the microbiota colonizing the gingival mucous membrane was studied. 14 healthy male volunteers took part. After a 3 week pre-experimental period of intense oral hygiene, the participants refrained from all oral hygiene for 14 days. The buccal surfaces of cuspids and bicuspids on one side of the jaws were treated with a 1% aqueous solution of delmopinol hydrochloride (applied with a paint brush) 2 x a day for 7 days, while the contralateral side received placebo solution. On day 7, the application procedures were changed in that the test compound was applied on the teeth previously treated with placebo and vice versa. Plaque development was assessed clinically and by photo-based planimetric determination. The clinical recordings revealed that 89.3% of the placebo-treated surfaces displayed visible plaque on day 7, compared to 6.0% of the delmopinol hydrochloride treated surfaces. Delmopinol hydrochloride treatment of the previously placebo-treated surfaces resulted in a decrease in the number of surfaces with visible plaque from 89.3% on day 7 to 6% on day 14. These results were confirmed by the planimetric data. No significant change in the composition of the mucosal flora was observed during the experimental period. The present results indicate that delmopinol hydrochloride markedly reduces the formation of dental plaque on a clean tooth surface exposed to conditions which favour bacterial colonization. Furthermore, the substance appears to possess plaque-dissolving properties.

Administration, Topical↗

PubMed1996

Quantitative computed tomography of trabecular bone in the mandible.

OBJECTIVE: To evaluate the potential use of quantitative computed tomography (QCT) for the assessment of bone mineral density of the edentulous mandible prior to implant placement. METHODS: Ten 2 mm thick CT slices of anterior and posterior edentulous sections from 15 mandibles were obtained perpendicular to the buccal and lingual plates. The bone mineral density, expressed as the amount of calcium hydroxyapatite (mg cm-3) of the trabecular bone, was calculated using a method that takes into account the influence of fat. RESULTS: The variation of bone mineral density between mandibles was high. Anterior sections showed higher values than posterior sections and a variation was found within sections of the same mandible. CONCLUSION: CT provides a site-related measure of the bone mineral density in the mandible and appears potentially useful as a non-invasive method to determine a parameter that may reflect bone quality prior to implant placement.

Aged↗

PubMed1995

A new method to obtain bone biopsies at implant sites peri-operatively: technique and bone structure.

This study aims at evaluating an objective method for the description of bone structure in the human mandible. Human bone biopsies were harvested at mandibular implant sites prior to insertion of self-tapping Mark II fixtures. Altogether 15 biopsies were taken from 12 patients. Three patients donated 2 biopsies each, one proximally and one distally taken. Ground sections of about 100 microns thickness were prepared prior to microradiography. These sections were ground to a final thickness of about 10 microns followed by histological staining. Histomorphometrical analyses were performed on the microradiographed plates and on the ground sections. On average there was a bone area of about 54% calculated on the microradiographed plates (the 100-microns sections) versus a mean bone area of 62% light microscopically (the 10-microns sections). Bone lengths were calculated on the 10-microns sections in the central part (mid-line) and on each side of the mid-line, revealing a mean of 58% in the former case and a mean of 61% in the latter case. The amount of bone varied between individuals and in different locations of the same jaw. The postoperative healing period following fixture installation is standardized regardless of bone structure. It may in the future be appropriate to more individualize this healing period based on an objective bone quality score.

Adult↗

PubMed1995

Measurements of distances related to the mandibular canal in radiographs.

Before implant surgery in the mandibular side segment, it is of utmost interest to locate the mandibular canal in radiographs to avoid interference with the neurovascular bundle during surgery. Six mandibular specimens were radiographically examined with 2 panoramic and 3 tomographic techniques. The distances between the superior border of the canal and the alveolar crest and between the mandibular base and the inferior border of the canal were measured. In addition, the height of the canal was measured. The measurements were performed by 3 or 4 observers and compared with measurements on contact radiographs of the same areas. Tomography gave more accurate values of the above distances than panoramic techniques. The variation between observers in detecting the mandibular canal was large.

Aged↗

PubMed1995

Different types of inflammatory reactions in peri-implant soft tissues.

The aim of the present study was to analyze some features of the peri-implant mucosa at sites in the dog model which had been exposed to plaque accumulation for periods up to 9 months. The experiment was carried out in 5 labrador dogs. The mandibular right and left 2nd, 3rd and 4th premolars (2P2, 3P3, 4P4) and the 1st molars (1M1) were extracted. Following a 3-month healing period, 3 titanium fixtures (Nobelpharma AB, Göteborg, Sweden) were installed in the edentulous premolar/molar regions. Abutment connection was performed 3 months later and a meticulous plaque control period of 3 months was initiated. A clinical examination was performed at the end of this preparatory period and a main study period of 9 months continued. During this period, the plaque control regimen was maintained in the mesial and central (left: L1, 2 and right: R1, 2) implant segments, whereas plaque was allowed to accumulate on the distal implants, i.e.. L3 and R3. At the end of the main study period, i.e., 12 months after abutment connection, the clinical examination was repeated, the animals perfused and biopsies obtained. Semi-thin sections were produced for histometric and morphometric analyses. The peri-implant mucosa at implant sites exposed to daily and comprehensive plaque control at biopsy was clinically noninflamed and the connective tissue lateral to a junctional epithelium was devoid of accumulations of inflammatory cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Bone Loss↗

PubMed1995

Resolution of ligature-induced peri-implantitis lesions in the dog.

The present experiment in the Labrador dog was performed to study tissue alterations that occurred in a peri-implantitis lesion following ligature removal. The study was carried out in 5, 1-year old Labrador dogs. The mandibular right and left 1st molars and 4th and 3rd premolars were extracted to establish recipient sites for implants. After 3 months of healing, 4 titanium fixtures, 2 in each jaw quadrant, were installed and abutment connection carried out in a 2nd stage procedure after another 3 months. After a 6-month period of healing, cotton floss ligatures were placed in a submarginal position around the neck of the fixture abutments. The ligatures were forced into a position "apical" of the margin of the peri-implant mucosa and secured. When the tissue destruction after 4-6 weeks was found to amount to about 25% of the original bone height at each individual implant, the ligatures were removed. 2 dogs were sacrificed 1 month and 3 dogs 3 months after ligature removal. The animals were perfused with a fixative and block biopsies were obtained from the implant sites. The biopsies were prepared for histometric and morphometric analyses.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Bone Loss↗

PubMed1995

Computer-assisted image processing for quantitative measurements of fractional bone area. A methodologic study.

The purpose of this study was to evaluate a method for computer-assisted image processing to assess quantitatively fractional bone volume in sections of bone biopsies (part I). A second purpose was to apply this method in an experimental study to determine bone loss by measuring fractional bone area in sections of calvarial bone of gastrectomized rats and to compare this with a control group. Stained paraffin sections of skull bone of young rabbits (part I) and rats (part II) were examined. The histologic sections were placed on a microscope. A video camera was connected to the microscope, and the image transferred to a display monitor connected to a PC with dedicated software, performing the measurements. In the first part of the study tests of the reproducibility of the method were performed. The influence of factors such as external illumination and light intensity in the microscope was evaluated by measuring the same area several times at different times (= different illumination) and at different microscope light intensity levels. The automatic method was compared with a manual method, using a Merz grid but automatically calculated. The difference between the means of the manual and automatic measurements was determined with the paired t test. In the second part of the study the unpaired t test was used to determine the differences between the control group and experimental group, both for the manually and the automatically measured values.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Structure of calvaria after gastrectomy. An experimental study in the rat.

BACKGROUND: Gastrectomy induces bone loss, suggesting that the stomach is important for calcium homeostasis. In this study we examined the effects of gastrectomy, with or without CaCl2 supplementation, on the structure of the calvaria of the rat. METHODS: The calvaria were dissected out and transilluminated, and the calvaria thickness was measured before (micrometer) and after fixation and sectioning (microscopy). Sections of the skull were analysed planimetrically for bone tissue area, using computer-assisted image analysis. RESULTS: The time course of the gastrectomy-produced bone loss was studied. After 4 weeks the remaining bone represented about 70% of that in control rats, and after 8 weeks the value was 50%. The thickness of the calvaria was lower in gastrectomized rats than in sham-operated controls. Bone marrow and samples from liver and spleen were examined; no differences were found between experimental and control groups. Daily ingestion of 100 mg CaCl2.2H2O did not prevent the bone loss. CONCLUSIONS: It is unlikely that the gastrectomy-produced bone loss reflects calcium deficiency. The results rather support the view that the stomach is important for calcium homeostasis through another mechanism, perhaps involving a hypothetical gastric hormone.

Animals↗

PubMed1994

Oral microflora of the ferret at the gingival sulcus and mucosa membrane in relation to ligature-induced periodontitis.

The aim of this study was to describe, in the domestic ferret, the composition of the normal gingival sulcus and the near related mucosa microflora and the shift in the composition during an acute periodontal breakdown induced by the placement of ligatures. Five animals were used. At the start of the experiment (day 0) and before the placement of the ligatures, 2 microbiological samples were obtained from the gingival sulcus and the related mucosa at the mid-buccal surface of the right upper P4. The same sites were sampled on the left side, serving as control sites. On day 28, new microbiological samples were taken from the same 4 sites. The samples were analyzed with darkfield microscopy and with viable counts. In the darkfield analysis, on day 0, the predominant bacterial morphotype was cocci, ranging from 88-92%. The viable counts showed that nearly 100% of the total cultivable flora was composed of facultative anaerobic gram-negative and gram-positive rods. Pasteurella spp., Corynebacterium spp. and Rothia spp. were the major components of these bacterial groups. No anaerobic bacteria were detected. On day 28, cocci decreased to approximately 75% in the experimental gingival sulcus sample, and filaments and rods increased significantly. Spirochetes remained largely unchanged during the experiment. The composition of the experimental site samples changed. There was a decrease in the mean numbers of facultative anaerobic gram-positive rods, and approximately one third of the microflora comprised anaerobic gram-negative rods, mainly Porphyromonas gingivalis and Fusobacterium spp. Although the composition of the microflora of the ferret presented few similarities to that described in dogs and monkeys, the anaerobic portion of the gingival sulcus and oral mucosa microflora related to ligature-induced periodontitis presented microorganisms observed in experimental periodontitis both in dogs and monkeys as well as in human periodontal diseases.

Animals↗

PubMed1994

Clinical and histological evaluation of ligature-induced periodontitis in the domestic ferret.

The aim of this study was to evaluate the clinical and histological characteristics of ligature induced periodontitis in 12 domestic ferrets. On day 0, silk ligatures were placed at the gingival margin level of selected experimental teeth. The contralateral teeth served as control teeth. On day 14, 4 animals and on day 28, 8 animals were sacrificed. Clinical measurements including gingival index (GI), probing pocket depth (PPD) and probing attachment level (PAL) were taken in 5 animals on days 0, 14 and 28. Histological sections were prepared for light microscopy. The histometric measurements performed were (1) the distance between the cemento-enamel junction (CEJ) and the alveolar bone crest and (2) the distance between CEJ and connective tissue attachment level. The number of sections with root resorption areas was also observed. Cell counts were taken in 4 different areas. Clinical results showed, on days 14 and 28, a significant increase of the mean values of PPD and PAL at the experimental teeth when compared to the control teeth. The histometric results showed a significant loss of connective tissue attachment and bone loss in the experimental teeth on day 14. On day 28, the results were similar, although more sections with root resorption areas were observed in the experimental teeth. The predominant inflammatory cell in all the 4 experimental areas analyzed was polymorphonuclears (PMN), and they were mainly increased in areas closely related to the junctional epithelium. The results indicate that the domestic ferret may be used as an experimental animal in the ligature-induced periodontitis model.

Alveolar Bone Loss↗

PubMed1994

Clinical and histological evaluation of ligature-induced periodontal breakdown in domestic ferrets immunosuppressed by Cyclosporin-A.

The aim of this study was to evaluate, clinically and histologically, the effect of Cyclosporin-A (CyA) on the progression of the periodontal breakdown in the domestic ferret, using the ligature induced periodontitis model. At the start of the experiment (day 0), silk ligatures were placed at the gingival margin level of experimental teeth. The contralateral teeth served as non-ligated control teeth. Clinical measurements included gingival index, probing pocket depth (PPD), probing attachment level (PAL) and gingival overgrowth (GO) and they were performed on days 0, 14 and 28. Cyclosporin-A, 10 mg/kg/d, was given subcutaneously from day 0 to 21, while in the last week there was a reduction of this dose to 5 mg/kg/d. Blood samples were taken on days 0, 14 and 28. On day 28 the animals were sacrificed. Histological sections were prepared for light microscopy. The histometric measurements performed were: (1) the distance between cemento-enamel junction and the alveolar bone crest and (2) loss of connective tissue attachment. The number of sections with root resorption areas was observed. Cell counts were taken in 4 different areas. The results showed, on days 14 and 28, a significant increase of the mean values of PPD and PAL at experimental teeth as compared to the control teeth. GO was present on experimental teeth on days 14 and 28. On day 28, the control teeth presented a very small increase in GO, mainly at the buccal sites of P4 and M1. The histometric results showed a significant loss of attachment and bone resorption in the experimental teeth. Root resorption was found in experimental teeth only. The predominant inflammatory cell in the 4 experimental areas was polymorphonuclears.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Bone Loss↗

PubMed1993

Influence of three alloplastic materials on calvarial bone healing. An experimental evaluation of HTR-polymer, lactomer beads, and a carrier gel.

This study evaluated experimentally three alloplastic materials (HTR-polymer, lactomer beads, and a resorbable gel substance). A bioassay performed in a critical size defect rat model disclosed no osteoinductive capacity of any material. A total of 72 trephine calvarial 5-mm defects were created in 18 rabbits. The inlays were tested relative to control (empty) defects in a varied pattern, and the results were assessed by light microscopy and contact radiography after 4 and 15 weeks. The HTR-polymer alone or combined with bone chips displayed the most rapid early bone regeneration and more mature bone marrow redevelopment. The present form of the gel material seems to be less suitable for use as a carrier substance because of the intense inflammatory response produced.

Animals↗

PubMed1993

Laser Doppler flowmetry of blood perfusion in mucoperiosteal flaps covering membranes in bone augmentation and implant procedures. A pilot study in dogs.

In guided tissue regeneration (GTR) procedures, flap recession or sloughing may occur as an unwanted sequel to the placement of a membrane. This study was designed to assess the applicability of laser Doppler flowmetry (LDF) in the evaluation of blood perfusion in the mucoperiosteal flap covering the membrane. Five Labrador dogs were initially used in the study, but one animal was later excluded due to post-operative problems. Maxillary premolar teeth were extracted and full thickness mucoperiosteal flaps were raised. Following removal of the buccal bone plate, 4 titanium implants were placed on each side. An experimental biodegradable polylactic-acid membrane was placed over the fixtures on one side to allow for GTR. The mucoperiosteal flap was repositioned and secured with sutures. The contralateral side served as control with no membrane. Blood perfusion was measured in the flaps before surgery, immediately after suturing and at 24, 48 and 72 h postoperatively. A laser Doppler flowmeter was used to assess the blood perfusion. In 3 animals the membrane was exposed within 2 weeks post-operatively, and in these 3 animals the LDF values were lower on the membrane side than on the control side. The mean LDF value was lower on the membrane side for each of the 4 periods studied. The findings suggest that LDF can be a valuable method to study blood perfusion of oral mucosal flaps and that there may be a relationship between a reduced relative LDF value and subsequent exposure of the membrane to the oral environment.

Alveolar Ridge Augmentation↗

PubMed1993

Normal histologic features of domestic ferret periodontium.

The normal histologic features of the periodontal tissues in 17 domestic ferrets (10 male and 7 female) are described. The following teeth were histologically evaluated: canines, the maxillary third premolar (P3), the mandibular fourth premolar (P4), the carnassial teeth (P4 in the maxilla and the first molar, M1, in the mandible) and the next molar after the carnassials (M1 in the maxilla and M2 in the mandible). After histologic preparation for light microscopy, the sections were analyzed at magnifications of x 20 and x 100. The histometric measurements performed were 1) distance between the cementoenamel junction (CEJ) and the alveolar bone crest, 2) distance between CEJ and the most coronal connective tissue, 3) root length, 4) width of the periodontal ligament at three different locations along the root surface, and 5) cementum layer thickness at the most apical portion of the root. The number of sections exhibiting root resorption was counted. The results gave the normal values of some common periodontal variables and suggested a possible future use of the domestic ferret as an alternative experimental animal in periodontology.

Animals↗

PubMed1993

Periodontal indices around natural and titanium abutments: a longitudinal multicenter study.

This multicenter prospective study on the use of an implant system involved 9 centers and reports on the periodontal aspects after 3 years of observation. A total of 558 implants in 159 patients with 197 bridges all independent from natural teeth were originally included. Because of failures and patient withdrawals the number of implants was reduced to 460 and bridges to 174. The cumulative success rate for implants, starting from implant placement, is 94.3% after 2 years and 93.9% after 3 years indicating a leveling of implant loss. Failures concentrated in patients with a high plaque index. The loss of marginal bone was during the second and third years only 0.03 mm per year as an average while it was 0.4 mm during the first year. There were no reports of intense gingival inflammation in any of the patients and the plaque and gingivitis index behaved similarly around abutments and teeth. The probing pocket depth was significantly reduced over the observation time. The resistance towards marginal bone loss around these implants confirms the previous studies on fully edentulous patients.

Adolescent↗

PubMed1993

Calcified cartilage zone and its dimensional relationship to the articular cartilage in the human temporomandibular joint of elderly individuals.

The aim was to describe the appearance of the calcified cartilage zone (CCZ) and to determine its dimensional relationship to the articular cartilage thickness in the normal human temporomandibular joint. An autopsy material comprising 21 joints from 12 elderly individuals was examined microscopically. The appearance of the CCZ was examined, and the thickness of the CCZ and of the total articular cartilage was measured in 18 different positions in each joint. The CCZ was outlined by a flat or gently undulating tidemark and an irregular osteochondral junction. The cellularity of the CCZ varied extensively. The cells were numerous in the CCZ when the overlying articular cartilage displayed high cellularity. Statistical analysis of the measurements demonstrated a relationship (p < 0.001) between the thickness of the CCZ and of the articular cartilage. Our findings, both qualitative and quantitative, indicate a close relationship between the physiology of the CCZ and of the overlying articular cartilage.

Aged↗

PubMed1993

Local inflammatory reactions in juvenile and adult rats.

The present investigation was designed for the study of the early phases of local inflammatory reactions in juvenile and adult rats. A recently developed experimental model, based on continuous diffusion of an inflammation inducing agent, was applied. Thirty-five juvenile (6 weeks) and thirty-five adult (6 months) rats were used. Two sterile teflon tables were implanted subcutaneously on the back of each animal on each side of the midline. After three weeks, when a connective tissue capsula had developed, the tablets were replaced by one test tablet (containing lipopolysaccharide) and one fresh teflon tablet, respectively. In each group five animals were sacrificed on day 0 and fifteen animals on each of day 7 and 21. Biopsies comprising tablet and surrounding tissue were taken and exposed to routine histological treatment. The total number of cells was assessed in four defined areas in connection with each tablet. Cells classified as leukocytes were recorded separately. The analysis was performed at 1000x magnification in a light microscope. During the first seven days an increase in the number of leukocytes was seen in the tissue adjacent to the test tablets in both young and adult rats. After 21 days the number of leukocytes was still high in the adult group while in the juvenile group the number of leukocytes returned to the base-line level.

Aging↗

PubMed1992

Osseous response to implanted natural bone mineral and synthetic hydroxylapatite ceramic in the repair of experimental skull bone defects.

The purpose of this study was to assess and compare the osseous responses to implanted particles of resorbable anorganic xenograft bone mineral and non-resorbable dense synthetic hydroxylapatite of two different granule sizes. Four trephine calvarial defects were produced in each of 13 adult rabbits. The experimental materials were subsequently implanted in three defects, leaving the fourth defect for control purposes. Six animals were killed 4 weeks after surgery and seven at 14 weeks. The tissue responses were assessed by contact radiography, light microscopy, and histometry. The biocompatibility of the implants was confirmed. All defects healed uneventfully, although the resorbable hydroxylapatite seemed to promote initial bone regeneration. The importance to orthognathic surgery of early and effective healing of bone gaps, as well as of the advantage of implant resorbability to bone remodeling, are discussed.

Absorption↗