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Biomedical subjects

J Lindhe

Publications and source records attributed to J Lindhe.

At least 217 records · Page 12Linked to original sources
PubMed1980

Juvenile periodontitis. Some microbiological, histopathological and clinical characteristics.

The microflora of periodontal pockets and some histopathological characteristics of adjacent tissues from individuals with clinical signs of juvenile periodontitis were studied. Adult individuals with ordinary, rapidly advancing periodontitis served as controls. All of the patients had been referred for specialist treatment. Using criteria defined by Baer (19z1), the patients were assigned to one juvenile periodontitis (eight patients), one post-juvenile periodontitis (seven patients) and one adult periodontitis group (seven patients). Only lesions around the first molars and central incisors were studied. Bacterial samples were obtained from each site and were examined by darkfield microscopy and different morphological forms identified. The soft tissue of the diseased sites was excised. The biopsies were placed in a fixative, cut in 1-mm-thick blocks and embedded in Epon. In semithin sections the infiltrated connective tissue (ICT) was identified and the ICT portion further processed for electron microscopy. The numeric and volumetric densities of different cells and structures of the ICT were determined using a morphometric point-counting procedure. The results showed that juvenile periodontitis lesions are associated with a subgingival microflora, the composition of which is different from that of adult periodontitis. Thus, in patients belonging to the adult periodontitis and post-juvenile periodontitis groups, motile microorganisms dominated the subgingival plaque samples, whereas deep pockets in juvenile periodontitis lesions contained a flora dominated by coccoid cells and straight non-motile rods. The most pronounced difference in the composition of ICT between the juvenile on one hand and the post-juvenile and adult periodontitis lesions on the other, was related to the amount of extracellular structures. Thus, in post-juvenile and adult periodontitis lesions, collagen and residual tissue made up around 50% of the infiltrate. In the juvenile periodontitis lesions, however, extracellular structures occupied only around 20% of the volume. In the ICT of the juvenile periodontitis sites, around 70% of the volume was occupied by plasma cells and blast cells. The corresponding figures for the post-juvenile and adult periodontitis sites were 50 and 30%.

Adolescent↗
PubMed1980

Healing following implantation of periodontitis affected roots into bone tissue.

The aim of the present experiment was to study whether new connective tissue attachment can occur to root surfaces which have been exposed to the oral environment and subsequently implanted into bone tissue. Twelve teeth in three beagle dogs were subjected to progressive periodontal breakdown to half the root length by placing cotton floss ligatures around the neck of the teeth. Following crown resection and root hemisection, the teeth were root filled and the roots thoroughly scaled and planed. Each root was extracted and implanted into bone cavities prepared in edentolous areas of the jaws in such a way that epithelial migration into the wound and bacterial infection were prevented during healing. Root implantation and sacrifice of the animals were scheduled to allow for observation periods of 1, 2 and 3 months. The results demonstrated that new connective tissue attachment did not occur to root surfaces which had been exposed to the oral environment, but healing was characterized by repair phenomena, i.e. mainly root resorption and ankylosis. In those areas of the roots where periodontal ligament tissue was preserved following tooth extraction, a functionally oriented attachment apparatus was reformed. The results indicate that in addition to apical migration of junctional epithelium and regrowth of subgingival plaque, the type of cells which repopulate the wound area may jeopardize new connective tissue attachment.

Animals↗
PubMed1980

Healing following implantation of periodontitis-affected roots into gingival connective tissue.

The aim of the present investigation was to examine if a new connective tissue attachment can be established on a previously periodontitis involved root surface, located in contract with gingival connective tissue during healing. A total of 28 teeth in one dog (beagle) and two monkeys (Macaca cynomolgus) were subjected to experimental periodontal tissue breakdown by placing cotton floss ligatures or orthodontic elastics around the teeth. The ligatures were left in situ until about 50% of the supporting tissues had been lost. Following resection of the crowns, the teeth were root filled and the exposed parts of the roots thoroughly scaled and planed. Each root was extracted and implanted into grooves prepared in edentulous areas of the jaws in such a way that the root was embedded to half its circumference in bone, leaving the remaining part to be covered by the gingival connective tissue of the repositioned flap of the recipient site. Root implantation and sacrifice of the animals were scheduled to allow for observation periods of 2 and 3 months of healing. An analysis of histologic specimens, obtained from biopsies of the recipient site tissues, disclosed that a new fibrous attachment failed to form on a previously "exposed" root surface located in contact with gingival connective tissue. In areas of the roots where the periodontal ligament tissue was preserved prior to transplantation, a fibrous reattachment occurred between the root and the adjacent gingival tissue. The results indicate that gingival connective tissue does not possess the ability to establish conditions which enable the formation of a new connective tissue attachment.

Alveolar Process↗
PubMed1980

Effect of selective antimicrobial therapy on plaque and gingivitis in the dog.

The present investigation was performed to assess the effect of selective antibiotic therapy on developing plaque and gingivitis in dogs, which at the start of the study had normal gingiva. Fifteen beagle dogs were used. Throughout the entire observation period the animals were fed a diet which favored plaque accumulation. A baseline examination involved assessments of plaque, gingivitis and gingival exudate. The subgingival bacterial flora was assessed by dark-field microscopy. Subsequently the teeth of the right jaws were allowed to accumulate plaque. A careful tooth-cleaning program was maintained in the left jaws. Plaque and gingivitis assessments were repeated and subgingival plaque sampled in the right jaws after 14 and 28 days. On experimental day 28 the second part of the study was initiated. The dogs were randomly distributed into three groups of five animals each. A new baseline examination was performed in the left jaws, after which all tooth cleanings were terminated. During the subsequent 28 days each group of dogs was treated with one of three antimicrobial compounds (vancomycin, metronidazole or clindamycin). Examinations were repeated after 14 and 28 days. The results demonstrated that systemic administration of antimicrobial substances can reduce the rate of plaque formation, change the composition of the developing subgingival microbiota and prevent (or retard) the onset of gingivitis. A comparison of the ability of the three compounds to prevent the formation of a "gingivitis-inducing" plaque revealed that metronidazole and clindamycin were markedly more effective than vancomycin. In fact, in dogs receiving metronidazole and clindamycin treatment, the initiation of gingivitis was almost entirely prevented during the 28 days of treatment.

Animals↗
PubMed1980

Alterations of the position of the marginal soft tissue following periodontal surgery.

The present study was performed to examine the alterations of the position of the marginal soft tissue ("gingival margin") on the buccal surface of teeth in patients who following periodontal surgery were enrolled in a supervised maintenance care program for 10--11 years. The material consisted of 43 patients with severe destruction of the periodontal tissues. Following initial treatment comprising scaling, root planing and instructions in plaque control measures, deepened periodontal pockets were eliminated by the use of an apically repositioned flap procedure including osseous surgery to eliminate bony defects. After treatment, the patients were recalled once every 3--6 months for maintenance care. In all patients, the distance between the cemento-enamel junction and the gingival margin on the buccal surfaces of all treated teeth was assessed (1) prior to surgery, (2) after initial healing, and (3) at a reexamination 10--11 years after treatment. In addition, the presence or absence of keratinized gingiva was determined. The results showed that (1) during active periodontal treatment the position of the gingival margin was shifted in an apical direction, (2) this displacement was to some extent compensated for by a coronal regrowth during the postoperative maintenance care period, (3) the alterations of the position of the gingival margin followed a similar pattern in areas with and without a zone of keratinized gingiva, (4) the number of gingival units devoid of keratinized gingiva decreased during the maintenance care period.

Adult↗
PubMed1980

Conditions and pathological features of rapidly destructive, experimental periodontitis in dogs.

In order to analyze the conditions for rapidly destructive periodontitis and to describe the early histopathological changes and bone degradation, periodontitis lesions were produced in five male Beagle dogs, 8 to 12 months of age. Cotton floss ligatures were placed around the crowns of upper and lower third and fourth premolars for periods of 4, 7, 14, 21 days. The buccal gingival tissues, being slightly inflamed initially, were clinically scored for various symptoms of inflammation. Block biopsies of premorlars and the adjacent buccal periodontal tissues were taken and processed for light and electron microscopy. Depending on the ligature position in relation to the gingival margin (above, at, deep below) at the day of biopsy harvest, three groups of selected biopsies were formed, and randomly selected sections of these were used for various histometric measurements, for stereological estimation of the size and composition of the connective tissue infiltrate and the osteoclast density, and for general histopathological evaluation. The resulting data and observations implied that (1) onset and maintenance of this periodontitis lesion depend on subgingival ulceration, (2) rapid bone desstruction is the result of osteoclast activity stimulated by acute inflammation, and (3) bone degradation occurs independently of the loss of collagen fiber attachment and the apical migration of the junctional epithelium.

Alveolar Process↗
PubMed1980

The effect of levamisole on experimental gingivitis in the beagle dog.

The effect of Levamisole on gingivitis development was studied in three beagle dogs. Plaque accumulation was first allowed on one side of the jaws whereas the other side was subjected to careful tooth cleaning procedures. After 2 weeks' experimental gingivitis the dogs were given Levamisole and plaque accumulation was permitted on the other side of the jaws for another two weeks. The following parameters were investigated in the two gingivitis experiments: Plaque and Gingival Indices, Gingival Exudate measurements and histologic measurements. The biopsies were prepared both for light and electron microscopy. The clinical parameters did not show any differences between the two gingivitis experiments. The biopsies, however, demonstrated a larger area of infiltrated connective tissue and an increased number of leukocytes in the junctional epithelium in Levamisole-treated compared to normal animals.

Animals↗
PubMed1979

The effect of metronidazole on the development of plaque and gingivitis in the beagle dog.

The present investigation was performed in order to assess if the administration of metronidazole changed the composition of developing plaque in dogs, which at the start of the study were free from signs of gingivitis. Five beagle dogs were used. Throughout the observation period the animals were fed a diet which favored plaque accumulation. A baseline examination involved assessments of plaque, gingivitis and gingival exudate. Gingival biopsies were sampled and the tissue examined by a point counting procedure. The composition of the subgingival bacterial flora was assessed by dark-field microscopy. The bacteria were characterized into the following types: coccoid cells, straight rods, filaments, fusiforms, motile and curved rods and spirochetes. Following the baseline examination the teeth of the right jaws were allowed to accumulate plaque. A careful tooth cleaning program was maintained in the left jaw quadrants. Plaque and gingivitis assessments were repeated and biopsies sampled in the right jaws after 7, 14 and 28 days of no tooth cleaning. On experimental day 28 the second part of the study was initiated. A baseline examination was performed in the left jaws, after which the tooth cleaning program also in this part of the dentition was terminated. During the subsequent 28-day period each animal was given a dosage of 20 mg metronidazole/kilogram bodyweight/day. Clinical examinations and biopsies were repeated after 7, 14 and 28 days. The results demonstrated that metronidazole administered via the systemic route during a 28-day period can effectively decrease plaque and gingivitis development in dogs. The bacterial flora from subgingival sites of healthy gingiva was dominated by coccoid cells and straight rods. During the phase of developing gingivitis the percentage of coccoid cells and rods tended to decrease, while motile rods and spirochetes increased. During the 28 days of metronidazole treatment the subgingival plaque flora maintained its "healthy" composition, i.e. a gradual influx of motile rods and spirochetes was prevented.

Animals↗
PubMed1979

The effect of tetracycline and/or scaling on human periodontal disease.

The objective of this study was to test the efficacy of scaling and root planing with or without adjunctive tetracycline therapy in the treatment of periodonitis in humans. The presence of plaque, gingival inflammation, probing depths and attachment levels was assessed for all teeth in 12 patients with chronic, advanced periodontitis. After an initial examination all patients were given detailed oral hygiene instructions. The teeth in one-half of each arch were then scaled and root planed. The teeth in the contralateral half were not treated. Six patients were given tetracycline (1 gm/day) during the first and second weeks and the seventh and eighth weeks of the trial. The study thus included four different treatment groups: 1) no treatment, 2) scaling and root planing alone, 3) tetracycline administration alone, and 4) scaling and root planing combined with tetracycline administration. All patients were reexamined at 8 and 25 weeks subsequent to the initiation of therapy. Both PlI and GI scores decreased significantly in all groups. The GI scores were significantly lower in the scaled and root planed areas as compared to the contralateral sides at both the 8- and 25-week examinations. The PlI score was lower in the scaled and root planed areas only at the 25-week interval. The gingival probing depths were reduced in all groups. A significantly greater decrease in probing depth, however, was noted in scaled and root planed areas. There was a trend to gain of attachment in the treated areas but the magnitude of the gain was very small. The findings of the trail also revealed that the administration of tetracycline had only a minor effect on the parameters examined.

Adult↗
PubMed1979

Effect of hydrogen peroxide on developing plaque and gingivitis in man.

The present experiment was undertaken to assess the effect of hydrogen peroxide release during mouth rinsings on the composition of the microbiota of developing plaque in humans and the amount and pathogenecity of the plaque formed. The trial was designed as a double-blind crossover study of the effect of a mouthwash (Amosan) had a placebo rinse on the development of plaque and gingivitis in young adults. The active compound was available as a powder; the rinse consisted of 1.7 g powder dissolved in 30 ml hot tap water. Fourteen dental students participated in the trial. The students were examined during two consecutive periods, each consisting of one preparatory (during which active tooth cleaning measures were carefully practiced) and one main test period (during which mouth rinsings were the only plaque control measure). Each of the two test periods was initiated by a baseline examination following which the participants rinsed either with the active or the placebo mouthwash. The rinsings were performed immediately after breakfast, after lunch and after dinner. Measurements of Plaque and Gingival Index scores were performed 4, 7 and 14 days after the start of the no-toothbrushing period. Bacteria were sampled and examined after 7 and 14 days of trial. The results demonstrated that a mouthwash which released hydrogen peroxide effectively prevented the colonization of filaments, fusiforms, motile and curved rods as well as spirochetes in developing plaque. The mouthwash which was used as the only oral hygiene measure during a 2-week period furthermore markedly reduced the amount of plaque formed and significantly retarded gingivitis development. It is suggested that H202 released by mouthwashes during rinsing may prevent or retard the colonization and multiplication of anaerobic bacteria.

Clinical Trials as Topic↗