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Biomedical subjects

J Lindhe

Publications and source records attributed to J Lindhe.

At least 181 records · Page 10Linked to original sources
PubMed1984

Connective tissue reattachment as related to presence or absence of alveolar bone.

The present study was designed to examine if alveolar bone, located adjacent to a root surface deprived of its periodontal ligament and cementum layer, can stimulate the reformation of a connective tissue attachment. The maxillary and mandibular incisors in 3 monkeys were extracted. Immediately after tooth extraction, the buccal root surfaces of the incisors from the left side of the jaws were planed by means of curettes to a level corresponding to half the root length. All teeth were then reimplanted into their original sockets. However, before tooth reimplantation, the buccal alveolar bone plate was removed in 2 of the monkeys to a level corresponding to half the depth of the sockets. The animals were sacrificed 6 months after the reimplantation procedure. The jaws were removed and histological sections of the experimental teeth and adjacent periodontal tissues were produced. The sections were analyzed in the microscope and subjected to histometric measurements. The results demonstrated that, irrespective of the presence or absence of alveolar bone, a fibrous reattachment failed to form on that part of the reimplanted teeth which had been deprived of their periodontal ligament. This indicates that alveolar bone located adjacent to a root surface may have limited influence on the biological conditions which determine whether periodontal healing results in connective tissue reattachment or new attachment.

Alveolar Process↗
PubMed1984

Potentials for root resorption during periodontal wound healing.

The present study was undertaken to examine whether (1) the process of resorption, which invariably affects periodontitis involved reimplanted roots facing bone or gingival connective tissue during healing, is a transient phenomenon and, (2) root resorption can be prevented by permitting downgrowth of epithelium along the root surface. A total of 24 teeth in 2 monkeys (Macaca cynomolgus) was subjected to experimental periodontal tissue breakdown by the placement of elastic ligatures around the teeth. The ligatures were left in situ until about 50% of the supporting tissues had been lost. Following removal of the ligatures, the teeth were extracted and the denuded portions of the roots were scaled and planed. The crowns of the teeth were resected and the root canals filled with guttapercha. The roots were subsequently implanted into sockets prepared in the jaw bone in such a way that each root was embedded in bone except for a portion which was in contact with gingival connective tissue. 1 month prior to sacrifice of the animals, the cut surface of the coronal part of the roots was exposed by removal of the covering soft tissue. The epithelium was thereby allowed to migrate into the wound. Implantation of the roots was scheduled to provide healing periods of 1, 2, 3, 4, 8, 12, 16, 20 and 24 weeks before exposure of the roots. The histologic examination of the implant specimens disclosed that replacement resorption was a progressive process which eventually resulted in the elimination of the transplanted roots. It was possible to prevent root resorption in this model by permitting apical downgrowth of epithelium along the root surface during the initial phase of healing. The results are discussed in relation to procedures used in periodontal therapy.

Animals↗
PubMed1984

Recolonization of a subgingival microbiota following scaling in deep pockets.

The present investigation was carried out to study some aspects of the recolonization of a subgingival microbiota following subgingival instrumentation in sites with deep pockets. 16 patients were recruited for the study. From each patient 4 inflamed gingival sites with deep pockets were selected. These sites were examined for plaque, overt gingivitis, bleeding on probing and probing depth. Samples of the subgingival microbiota were obtained and examined in the darkfield microscope and in a Neubauer chamber. Following the Baseline examination the teeth of all 4 jaw quadrants were carefully scaled and planed. Subgingival instrumentation was carried out under local anesthesia and required between 2-4 appointments. The patients were subsequently divided into 2 groups (Groups A and B) consisting of 9 and 7 subjects, respectively. During the first 16 weeks of maintenance the patients of Group A were not supervised regarding their self-performed plaque control measures and they accumulated supragingival plaque. The patients of Group B, however, were during these 16 weeks recalled once every 2 weeks for professional tooth cleaning. In addition they rinsed twice daily with a 0.2% solution of chlorhexidine digluconate. Reexaminations including assessments of the same parameters as those studied at Baseline were performed after 2, 4, 8, 12 and 16 weeks. After the 16-week examination the patients of Group A received a new sequence of subgingival scaling and root planing. During the subsequent 16 weeks the patients of Group A were also recalled for professional tooth cleaning. They were reexamined 18, 20, 24, 28 and 32 weeks after the Baseline examination. Subgingival scaling followed by carefully supervised oral hygiene measures resulted in a marked improvement of periodontal conditions. This improvement was accompanied by a pronounced and sustained reduction in the motile segments of the subgingival microbiota. In the presence of supragingival plaque (Group A), however, a subgingival microbiota containing large numbers of spirochetes and motile rods was soon (4-8 weeks) reestablished. A small number of sites with deep pockets (greater than or equal to 8 mm) was not substantially reduced in depth following subgingival instrumentation. In these sites which were kept free from supragingival deposits a subgingival microbiota with a large proportion of motile bacteria soon recurred.

Adult↗
PubMed1984

Treatment of localized juvenile periodontitis. Results after 5 years.

The present investigation was performed to study the effect on localized juvenile periodontitis (LJP) of a treatment program which included tetracycline administration, surgical elimination of inflamed tissues, scaling and root planing, and careful plaque control during healing. Treatment of LJP lesions was carried out on 16 individuals aged 14 to 18 years (JP group). Lesions in first molars and incisors in a group of patients with adult periodontal disease (AP) were treated in an identical manner and served as controls. The presence of angular bony defects adjacent to first molars and incisors was first documented in all patients. Thereafter, a clinical examination was carried out, including assessments of oral hygiene status, gingival conditions, probing depths and attachment levels. The patients were subjected to a treatment program involving administration of tetracycline (250 mg 4 times per day for 2 weeks), removal of granulation tissue after flap elevation, and root curettage. After surgery, the patients were instructed to rinse the mouth with 0.2% chlorhexidine for 2 min twice a day during the first 2 postsurgical weeks. Professional tooth cleaning was carried out once every 3 months during a 5-year period. At 6, 12, 24 and 60 months after surgical treatment, the patients were re-examined regarding oral hygiene, gingival conditions, probing depths and attachment levels. Treatment of LJP lesions resulted in resolution of gingival inflammation, gain of clinical attachment, and refill of bone in angular bony defects. The healing of the lesions of this patient sample was similar to healing observed in patients with AP.

Adolescent↗
PubMed1984

Long-term effect of surgical/non-surgical treatment of periodontal disease.

The present investigation describes the effect of periodontal therapy in a group of patients who, following active treatment, were monitored over a 5-year period. One aim of the study was to analyze the rôle played by the patients' self-performed plaque control in preventing recurrent periodontitis. In addition, probing depth and attachment level alterations were studied separately for sites with initial probing depths of greater than or equal to 4 mm which were treated initially by either surgical or non-surgical procedures. Following active treatment (surgical/non-surgical), the patients were maintained on a plaque control regimen for 6 months, which included professional tooth cleaning once every 2 weeks. During the subsequent 18 months, the interval between the recall appointments was extended to 12 weeks and included prophylaxis as well as oral hygiene instruction. Following the 24-month examination, the interval between the recall appointments was further extended, now to 4-6 months. In addition, the maintenance program was restricted to oral hygiene instruction and professional, supragingival tooth cleaning, but further subgingival instrumentation was avoided. Clinical examinations including assessments of the oral hygiene, the gingival conditions, the probing depths and the attachment levels were performed at Baseline and after 24 and 60 months after completion of active therapy. Assessments of plaque and gingivitis were repeated annually. The results of the examinations showed that the patients' standard of self-maintained oral hygiene had a decisive influence on the long-term effect of treatment. Patients who during the 5 years of monitoring consistently had a high frequency of plaque-free tooth surfaces showed little evidence of recurrent periodontal disease, while patients who had a low frequency of plaque-free tooth surfaces had a high frequency of sites showing additional loss of attachment. The present findings demonstrated that sites with an initial pocket depth exceeding 3 mm responded equally well to non-surgical and surgical treatments. This statement is based on probing depth and attachment level data from sites which were free of plaque at the 6-, 12-, 24-, 36-, 48-, and 60-month reexaminations. It is suggested that the critical determinant in periodontal therapy is not the technique (surgical or non-surgical) that is used for the elimination of the subgingival infection, but the quality of the debridement of the root surface.

Adult↗
PubMed1984

Lack of significance of increased tooth mobility in experimental periodontitis.

This experiment was carried out in order to study the rate of progression of experimentally produced periodontal tissue breakdown in teeth which prior to the placement of cotton floss ligatures either had a normal or a permanently increased tooth mobility. Six beagle dogs were used. Trauma from occlusion of the jiggling type was produced on test teeth using a model previously described. Four months later experimental periodontal tissue breakdown was induced around both control and test teeth by placing cotton floss ligatures around the necks of the teeth. The ligatures which were exchanged once every 4 weeks during a 4-month period were replaced at the level of the gingival margin. Tooth mobility measurements and radiographic examinations were performed on Days 0, 30, 60, 90, 120, 160, 240 and 300. One dog was killed on Day 120 and the remaining 5 dogs on Day 300. Biopsies of the test and control teeth were fixed in formalin, decalcified, embedded in paraffin and mesiodistal sections cut with the microtome set at 4 micron. The results demonstrated that the degree of periodontal breakdown, initiated and maintained by ligature placement and plaque accumulation, was similar around teeth with a wide periodontal ligament space and in teeth with a normal width of the periodontium. In other words, progression of the plaque-associated lesions appeared to be unrelated to the width of the periodontal ligament space, i.e., to the degree of horizontal tooth mobility.

Animals↗
PubMed1983

Morphometric analysis of chronic inflammatory periapical lesions in root-filled teeth.

The cell distribution and the tissue composition of chronic inflammatory periapical lesions were analyzed from seventeen biopsies of root-filled maxillary canines and incisors. The specimens, which included the root tip, the soft granulation tissue, and portions of the surrounding alveolar bone, were subjected to a stereologic analysis based on morphometric point-counting procedures. Plasma cells and lymphocytes were found in large numbers (about 40 percent of the tissue volume) in areas close to the apical foramen. The number of fibroblasts and blast cells was comparatively low in this zone. Neutrophils, monocytes/macrophages, and mast cells accounted each for 1 to 2 percent of the infiltrated tissue volume. With increasing distance from the apex, the tissue examined harbored a decreasing number of inflammatory cells but an increased volume of noninfiltrated connective tissue. It was concluded that long-standing periapical lesions of root-filled teeth had many features in common with those of advanced inflammatory lesions of the marginal periodontium.

Cell Count↗
PubMed1983

Use of chlorhexidine as a plaque control measure following surgical treatment of periodontal disease.

Chlorhexidine mouth rinsing was compared with regularly performed professional tooth cleaning as a plaque control measure during healing following periodontal surgery. 14 patients were selected for the study. A Baseline examination included assessment of oral hygiene status, gingival condition, probing depth and attachment level. In each patient, scaling and root planing was carried out in conjunction with the modified Widman flap procedure including recontouring of alveolar bone irregularities in 2 jaw quadrants. The same procedures without osseous surgery were performed in contralateral jaw quadrants. 7 patients rinsed their mouth with a solution of 0.2% chlorhexidine digluconate twice a day, 2 min each time, for the first 6 months after therapy (healing phase). During the same period the remaining 7 patients were recalled every 2 weeks for professional tooth cleaning ad modum Axelsson & Lindhe (1974). Following reexamination after 6 months, all 14 patients were placed on a maintenance care program which included mechanical prophylaxis once every 3 months for 18 months (maintenance phase). Reexaminations were performed 6, 12 and 24 months after completion of initial therapy. The results revealed that professional tooth cleaning was somewhat more effective as a plaque control measure during healing following surgery than chlorhexidine mouth rinsing. At the end of the healing phase (1) there was a higher frequency of sites with pockets deeper than 4 mm in the patients who rinsed with chlorhexidine, (2) less gain of attachment occurred following chlorhexidine rinsing in pockets with an initial probing depth of greater than 4 mm, and (3) attachment loss in initially shallow pockets was somewhat more pronounced in the patients who rinsed with chlorhexidine. The differences in the effect of the 2 methods of plaque control, however, were small and in most respects diminished in the course of the maintenance phase. It was concluded that mouth rinsing with chlorhexidine is a proper alternative to plaque control during healing following periodontal surgery.

Adult↗
PubMed1983

Comparison of statistical methods of analysis of data from clinical periodontal trials.

Data from clinical trials have commonly been analyzed by seeking differences between means of clinical measurements in groups treated in different ways. Such differences may be difficult to interpret clinically and fail to impart meaningful information to the research worker or clinician. Attachment level measurements taken from a group of well-maintained patients, initially treated by either scaling or Widman flap surgery, were artificially manipulated to impose known changes on the scaled group. Data from individual sites were analyzed by the t-test and Mann-Whitney test; and frequency distributions by the Kolmogorov-Smirnov 2-sample test and ridit analysis. Extreme changes were sought by the Moses test for extreme reactions and by creating contingency tables in which changes below arbitrary thresholds of change were eliminated. Examination of the results indicated that the mean was sensitive to small changes in large numbers of sites but insensitive to major changes in a smaller number of sites. Since the latter changes may be of significance to the research worker and clinician, it is recommended that the mean (or median values) be supplemented with the presentation of the frequency distribution of changes and an analysis seeking large changes in few sites.

Clinical Trials as Topic↗
PubMed1983

Plaque-induced gingival inflammation in the absence of attached gingiva in dogs.

The purpose of this experiment was to evaluate the effect of plaque infection on gingival units (1) with or without support of attached gingiva and (2) with different height of the attachment apparatus. 7 beagle dogs were used. Prior to the initiation of the study 4 different types of "dentogingival" units had been established in each dog by the use of excisional and grafting procedures, namely (1) normal non-operated free gingival units supported by a wide zone of attached gingiva and normal height of the attachment apparatus, (2) regenerated free gingival units supported by loosely attached alveolar mucosa and normal height of the attachment apparatus, (3) regenerated free gingival units supported by loosely attached alveolar mucosa and reduced height of the attachment apparatus and (4) regenerated free gingival units supported by a wide zone of attached gingiva and reduced height of the supporting apparatus. A baseline examination involved assessments of plaque, gingivitis, gingival exudate, probing depth, clinical attachment level, position of the "soft tissue margin" and width of attached gingiva. Following this examination 2 of the dogs were scheduled for biopsy and sacrificed. The remaining 5 dogs were for 40 days placed on a diet regimen which allowed plaque accumulation. The clinical examination was repeated and biopsies sampled at the end of this period. Following preparation the biopsy material was subjected to histometric and morphometric analysis. The results showed that the free gingiva which regenerated following surgical excision of the entire gingiva or following soft tissue grafting, was in most respects, clinically as well as histologically, similar to the "normal" free gingiva. The data obtained after 40 days of plaque accumulation did not reveal any differences between the various "dentogingival" units regarding size and apical extension of the infiltrated portion of the connective tissue. It was concluded that a free gingival unit which is supported by loosely attached alveolar mucosa is not more susceptible to inflammation than a free gingival unit which is supported by a wide zone of attached gingiva.

Animals↗
PubMed1983

Progression of periodontal disease in adult subjects in the absence of periodontal therapy.

Progression of periodontal disease in adult subjects in the absence of periodontal therapy was monitored in 2 populations. One group of 64 Swedish subjects (mean age 40.5 years at entry) with mild to moderate periodontal attachment loss was monitored for attachment level changes at baseline, 3 and 6 years. A second group of 36 Americans (mean age 34.3 years at entry) with advanced destructive periodontal disease was monitored for attachment level changes at baseline and 1 year. Of 4101 sites examined at baseline and at 3 years in the Swedish subjects, only 158 sites (3.9%) showed attachment loss of more than 2 mm. No measurable change was found in 1440 sites (35.1%). Of 4097 sites examined at 3 and 6 years, 67 sites (1.6%) showed attachment loss greater than 2 mm; 57.4% of sites showed no measurable change; and 19 sites (0.5%) showed a decrease in probeable attachment level of more than 2 mm. During the 6-year interval, 523 sites (11.6%) showed attachment loss of more than 2 mm; 20% of sites showed no measurable change and 11 sites (0.2%) showed more than 2 mm of attachment "gain". Approximately 50% of sites that showed no measurable change in the first 3-year period showed loss in the next 3 years. In contrast, of the sites which showed some level of attachment loss in the first period, approximately 2/3 showed no loss in the second monitoring period. Of 3210 sites monitored in the American subjects, 102 sites (3.2%) exhibited more than 2 mm of additional attachment loss; 26% of sites showed no measurable change and 138 sites (4.3%) showed a decrease in probeable attachment level of more than 2 mm. The association between attachment level changes and initial attachment level (baseline) was examined by regression analysis. The slopes of the regression lines for both populations were not consistent with a hypothesis that sites with more advanced attachment loss are more prone to additional destruction, in the absence of treatment, than sites with initially less attachment loss. In the American group, some sites with initially advanced attachment loss, exhibited a decrease in probing attachment level.

Adolescent↗
PubMed1983

Effect of long-term tetracycline therapy on human periodontal disease.

The present investigation was performed to study the effect of long-term, low dosage tetracycline therapy on advanced periodontal disease in humans. 14 volunteers participated in the trial. Each of the participants had at least 4 pairs of diseased sites around contralateral premolars and incisors with deep pockets and advanced bone loss. The trial extended over a 50-week period and was designed as a double-blind split-mouth study. A Baseline examination included assessments of oral hygiene, gingival conditions, probing depth, attachment level and analysis of the composition of the subgingival microbiota in samples obtained from 8 selected diseased sites. All participants received oral hygiene instruction. In each patient 2 quadrants of the mouth, chosen at random, were treated by scaling and root planing. The 2 remaining quadrants were left unscaled. Following the Baseline examination the patients were randomly distributed into 2 groups of 7 members each. In one of the groups the patients received tetracycline on a daily basis during a 50-week period. The participants of the control group received placebo. Reexaminations were performed 2, 10, 20, 30 and 50 weeks after the Baseline examination. The findings demonstrated that in patients with advanced periodontal disease long-term tetracycline therapy in the absence of scaling resulted in the establishment of a subgingival microbiota almost devoid of motile bacteria and in markedly reduced signs of gingivitis, probing depth and attachment loss. In fact, the alterations observed as a result of tetracycline administration to patients with excellent self-performed plaque control were similar to those obtained by conventional scaling and root planing in the control group.

Adult↗
PubMed1983

Role of attached gingiva for maintenance of periodontal health. Healing following excisional and grafting procedures in dogs.

The present study was undertaken to analyze the role of attached gingiva for the maintenance of periodontal health in sites with normal and reduced height of the supporting apparatus. Furthermore, the effect of excision and grafting of gingiva on some parameters describing dimensions and location of the periodontal tissues was evaluated. 7 beagle dogs were used. A baseline examination comprised assessments of dental plaque, gingival conditions, attachment level, position of the gingival margin and width of the keratinized and the attached gingiva. In the right side of the jaws (experimental side) a 6-month period of periodontal tissue breakdown was followed by surgical excision of the entire zone of the gingiva. After another 4-month period of healing with daily plaque control, a gingival graft was inserted in one quadrant of the experimental side to regain a zone of attached gingiva while the other quadrant of the experimental side was left ungrafted. In the left side of the jaws (control side), the teeth were subjected to daily meticulous plaque control during the entire study. In one of the control quadrants the entire zone of the keratinized and attached gingiva was excised at a time point corresponding to the grafting procedure in the experimental side, while the gingiva in the remaining control jaw quadrant was left unoperated. Clinical examinations of all control and experimental tooth units were repeated at certain time intervals during the course of the study. The final examination was carried out 4 months after grafting. The results of the experiment showed that in sites exposed to careful plaque control measures gingival health could be established and maintained without sign of recession of the gingival margin or loss of attachment, independent of (1) presence or absence of attached gingiva, (2) width of keratinized gingiva or (3) height of the supporting attachment apparatus. Following surgical excision of the entire gingiva, all buccal sites regained a zone of keratinized gingiva, but most sites were lacking attached gingiva. Furthermore, grafting of gingival tissue significantly increased the width of the keratinized and the attached gingiva but had no obvious effect on the position of the gingival margin or the level of the attachment.

Animals↗