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Biomedical subjects

J Lindhe

Publications and source records attributed to J Lindhe.

At least 163 records · Page 9Linked to original sources
PubMed1986

A clinical evaluation of fixed-bridge restorations supported by the combination of teeth and osseointegrated titanium implants.

The present paper reports on the result of the use of osseointegrated titanium fixtures and teeth as combined abutments for fixed-bridge restorations in 10 partially dentate patients. In these patients, the remaining teeth were too few or too unfavourably distributed in the jaws to serve as sole abutments for fixed bridgework. Titanium fixtures ad modum Brånemark were therefore implanted in suitable positions and used as abutments in combination with the remaining teeth. Evaluations at periods of 6 to 30 months postoperatively revealed good clinical results. Some tissue reactions, however, were also observed, indicating the presence of certain clinically significant differences in the functional behaviour of tooth abutments and titanium fixture abutments. These reactions and differences are discussed.

Adult↗
PubMed1986

Healing following surgical and non-surgical treatment of juvenile periodontitis. A 5-year longitudinal study.

The patient sample used in the present study comprised 16 young individuals who were referred for treatment of advanced periodontal disease. Based upon the age of the patients and the location of the diseased sites, the patients were divided into 2 groups; a juvenile periodontitis group (JP) and a post-juvenile periodontitis group (post-JP). The patients in the JP group had periodontal lesions only at first molars and incisors. All 16 subjects were in excellent general health and none had been treated with antibiotics during a period of at least 12 months prior to the 1st examination. At a baseline examination and 6, 24 and 60 months after active therapy, the diseased sites were examined regarding plaque, gingivitis, probing pocket depths, probing attachment level, recession of the gingival margin and marginal alveolar bone level. Following a case presentation and instruction in proper oral hygiene measures, the 16 subjects were subjected to periodontal treatment, utilizing a split mouth design. By random selection, the diseased sites in one side of the jaws were treated by scaling and root planing in conjunction with a "modified Widman flap" procedure, while in the contralateral jaw quadrants treatment was restricted to scaling and root planing. During the 1st 6 months following active therapy, the patients were subjected to professional tooth cleaning once every 4 weeks. Subsequently, the interval between the recall appointment was 3 months. 2 years after treatment, this maintenance care program was terminated. A final examination was performed 5 years after therapy. None of the patients involved in the trial received antibiotic treatment during the 5 years of observation. The findings of the present study revealed that the response of the periodontal tissues to therapy, both in the JP and the post-JP group of patients, was almost identical to that found for similar types of treatment in patients with adult periodontitis. The re-examinations performed after 6, 24 and 60 months following active therapy of JP and post-JP lesions revealed that excision of the granulation tissue in conjunction with flap elevation did not enhance the degree of probing pocket depth reduction, probing attachment gain and bone fill that occurred following meticulous root surface instrumentation.

Adolescent↗
PubMed1985

Intraclass correlations of periodontal measurements.

Components of variance and intraclass correlation coefficients were computed for changes in attachment level, pocket depth, gingival and plaque index scores for 5 groups of treated periodontal disease patients and 1 group of untreated subjects with periodontal disease. The intraclass correlation coefficients for attachment level change ranged from 0.011 to 0.165 (median 0.067), while intraclass correlation coefficients for pocket depth changes ranged from -0.009 to 0.178 (median 0.071). These intraclass correlation coefficients were much lower than those computed for changes in measurements of plaque which ranged from 0.086 to 0.568 (median 0.268) or gingival inflammation which ranged from 0.119 to 0.522 (median 0.264). Intraclass correlation coefficients at baseline for pocket depths ranged from 0.000 to 0.199 (median 0.053), for plaque accumulation from 0.121 to 0.531 (median 0.222) and for gingival inflammation from 0.229 to 0.596 (median 0.391). The differences in the intraclass correlation coefficients between pocket depth and attachment level on the one hand and plaque accumulation or gingival inflammation on the other could not be explained on the basis of differences in the measurement scale employed, since collapsing measurement scales had little effect on the intraclass correlation coefficients. The observed larger intraclass correlation coefficients for changes in plaque and gingival indices suggest a larger rôle for host contribution to these measurements. In contrast, the data suggest that the major but by no means the sole factor determining the variability of attachment level or pocket depth changes is the nature of the local factors.

Chlorhexidine↗
PubMed1985

Scaling and granulation tissue removal in periodontal therapy.

The present clinical trial was performed to study whether subgingival scaling is a method of therapy which is equally effective as "access" flaps in reducing gingivitis and probing depths and in improving probing attachment levels. The study was also designed to assess whether granulation tissue removal is a determining factor for proper healing in the treatment of periodontal disease. 15 patients with advanced periodontal disease were included in the study. Each patient had at least 4 sites in each quadrant of the jaws with probing depths exceeding 6 mm. A baseline examination was performed to assess the following parameters: the oral hygiene status, the gingival conditions, the probing pocket depths and the probing attachment levels. In addition, in each quadrant, 3 approximal sites were selected for analysis of the subgingival microbiota. All of these sites showed signs of gingivitis. One site had a probing depth of less than 4 mm, another a probing depth between 4 and 6 mm and the third site had a probing depth exceeding 6 mm. The subgingival bacterial samples were studied by dark-field microscopy and the % of spirochetes and motile rods was assessed. By random selection the 4 jaw quadrants in each patient were treated for periodontal disease by the use of (1) the modified Widman flap procedure, (2) the modified Kirkland flap procedure or by (3) nonsurgical scaling and root planing. In all, 20 quadrants were treated with each of the 3 procedures. After the termination of active periodontal treatment, all patients were recalled for professional tooth cleaning once every 2 weeks during a 12-week period. Subsequently, they were recalled for prophylaxis every 3 months. The patients were examined 6 and 12 months after treatment using the same parameters as used at baseline. The data from the examinations demonstrated that subgingival scaling is an effective measure in the treatment of periodontal disease. Both in terms of average gingivitis resolution and average probing depth reduction, non-surgical therapy appeared to be equally effective as a surgical approach to treatment. It was also observed, however, that following non-surgical treatment, a larger number of sites with pockets exceeding 6 mm remained than following surgical therapy. Most of these deep pockets in non-surgically treated quadrants bled on probing to the base of the pocket. In addition, the subgingival microbiota of such sites were found to harbor more than 20% spirochetes and motile rods.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1985

New attachment formation on teeth with a reduced but healthy periodontal ligament.

The present investigation was undertaken to examine whether a new connective tissue attachment will form on previously periodontitis-involved roots when reduced but healthy periodontal ligament tissue persists following periodontal treatment and the epithelium is prevented from migrating into the wound. In each of 4 monkeys, periodontal tissue breakdown was induced around one maxillary and one mandibular second premolar or first molar by placing orthodontic elastics around the teeth. The elastics were kept in situ until about 50% of the supporting tissues had been lost. 3 months following removal of the elastics, the crowns of the teeth were resected. The pocket epithelium and subjacent granulation tissue were excised and the cementum of the periodontitis-involved part of the roots was removed using a diamond bur. The roots were covered with a mucosal flap. The animals were sacrificed after 3 months of healing. The jaws were removed and histological sections of the experimental roots including their surrounding periodontal tissues were produced. The microscopic analysis disclosed that in all roots, new cementum with inserting collagen fibers had formed in the apical portion of the previously exposed root surfaces. It was always in continuity with the original cementum layer apical to the instrumental part of the root and was thickest in its apical portion, becoming gradually thinner in the coronal direction. In the roots, which for the entire length of the study remained covered by the oral mucosa, the extension in the coronal direction of this newly formed fibrous attachment amounted to an average of 1.0 mm with a range from 0.1 mm to 2.6 mm. These findings were interpreted to mean that new attachment is formed by coronal migration of cells originating from the periodontal ligament.

Animals↗
PubMed1985

Some effects of a Sanguinarine-containing mouthrinse on developing plaque and gingivitis.

The present clinical trial was performed to assess the effect of a Sanguinarine-containing mouthrinse on developing plaque and gingivitis in man. The trial was designed as a blind cross-over study. The active mouthrinse consisted of a 0.03% aqueous solution of Sanguinaria extract; an aqueous solution with similar color and taste as the active rinse was used as the placebo preparation. 14 dental students participated in the trial. At the start of each of 2 test phases, their gingival conditions were normal and their tooth surfaces free from dental plaque. Following a baseline examination, the participants refrained from mechanical tooth cleaning measures for 2 weeks. They rinsed twice daily with either the active or the placebo mouthrinse. Clinical examinations of plaque and gingivitis were repeated after 4, 7 and 14 days use of the mouthrinse preparation. During the second test phase of no mechanical tooth cleaning, the subjects who previously had rinsed with the placebo solution now used the active compound and vice versa. The results demonstrated that the Sanguinarine-containing mouthrinse was effective in reducing plaque formation and retarding the development of gingivitis.

Adult↗
PubMed1985

Healing after root reimplantation in the monkey.

The aim of the present investigation was to evaluate the regenerative potential of the periodontal tissues following tooth reimplantation using a model which excluded the dentogingival epithelium from the process of healing. Maxillary and mandibular incisors, premolars and molars of 5 monkeys were used. Following root filling of all experimental teeth, the teeth were divided into 3 experimental groups. In 1 group, the teeth were extracted following the elevation of full thickness flaps. The crowns were separated from the roots at the level of the buccal cemento-enamel junction and the roots immediately reimplanted into their sockets. The flaps were replaced and sutured to accomplish complete coverage of the roots. In a 2nd group, the teeth were subjected to the same experimental procedure, but in addition, the buccal alveolar bone was removed to about half its original height prior to root reimplantation. The teeth of the 3rd group were subjected to identical experimental procedures as for group II with the addition that the buccal root surfaces were planed to the level of the surgically created bone crest. The animals were sacrificed after 6 months of healing. The jaws were removed and histological specimens prepared for microscopic examination. The results showed that a complete fibrous re-attachment formed onto roots on which the original periodontal ligament tissue was preserved. This occurred irrespective of whether the roots were reimplanted into sockets with normal (group I) or reduced (group II) bone height. When the original periodontal ligament tissue was removed by root planing before reimplantation (group III), healing resulted in a significant amount of new connective tissue attachment. However, coronal to the newly formed fibrous attachment, the root surface frequently showed signs of resorption and particularly so in those roots which remained covered by the soft tissue during the entire course of healing. In the majority of the roots which perforated the covering soft tissue during the early phase of healing, the dentogingival epithelium had migrated apically into contact with the coronally generated fibrous attachment. In these cases, root resorption was never discernible. New bone formation occurred to a variable extent in the roots of groups II-III. No relationship was found, however, between the amount of connective tissue reattachment or new attachment and newly formed alveolar bone, which in turn indicates that bone tissue regrowth and periodontal ligament regeneration are unrelated phenomena.

Alveolar Process↗
PubMed1985

New attachment-reattachment following reconstructive periodontal surgery.

The present study was designed to evaluate if the conditions for reformation of a connective tissue attachment are less favorable on root surfaces which have lost their fibrous attachment because of periodontal disease than on root surfaces surgically deprived of their attachment apparatus. In each of 4 Green monkeys, 2 maxillary and 2 mandibular teeth were selected for experimentation. Periodontal breakdown was produced and allowed to progress to the mid-root level around one of the experimental teeth in both the maxilla and mandible by placing elastic ligatures around the neck of these teeth. 3 months after removal of the ligatures, the crown of the teeth was resected and the epithelium and the subjacent granulation tissue were removed. Using a diamond bur, circumferential defects similar to those obtained by the ligature induced destruction were then produced around the remaining 2 experimental teeth following resection of the crown. The root cementum on both groups of teeth was removed to the level of the reduced bone height. Finally, all roots were submerged to complete coverage by a mucosal flap. After 3 months of healing, the animals were sacrificed and the jaws removed and placed in fixative. After decalcification, histological sections of the experimental roots and their surrounding periodontal tissues were produced. No histological differences in the result of healing were discernible between the specimens of previously periodontitis-affected roots and roots with surgically created defects. New cementum with inserting collagen fibers had formed in the apical part of the instrumented surface in both groups of teeth.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Effect of age on healing following periodontal therapy.

The present investigation was performed in order to analyze the effect of age on healing of the periodontal tissues following treatment. The patients included in the present analysis consisted of 2 different samples. One group of 62 patients (sample A) was examined and treated between 1980 and 1982. 13 of these subjects were less than 40 years of age, 26 subjects were 40-49 years of age and 23 subjects were greater than 49 years old. The patients were subjected to periodontal surgery using the modified Widman flap procedure. During the active phase of treatment and for the subsequent 6 months of healing, all 62 patients were subjected to professional tooth cleaning. Instruction in proper oral hygiene measures was repeated and scaling was carried out when indicated. Sample B consisted of 21 subjects treated for advanced periodontal disease in 1969. Six of these patients were between 26 and 29 years of age at the start of treatment and 15 were at least 60 years old. The criterion for acceptance for the study in 1969 was that the patient should have lost 50% or more of his/her periodontal tissues. Following an initial examination, all patients were subjected to scaling and root planing and surgical elimination of pathologically deepened pockets. After the termination of active treatment, the patients were placed in a maintenance care program which included recall appointments every 3-6 months. Once a year after the completion of active treatment, all patients in this sample were examined regarding probing depths and clinical attachment levels. The findings from the present retrospective analyses failed to demonstrate that the age of patients with moderately advanced or advanced forms of periodontal tissue breakdown had an influence on the results of periodontal therapy. If anything, the younger patients appeared to heal with a higher frequency of shallow pockets and more gain of probing attachment than older patients.

Adult↗
PubMed1985

Improved periodontal conditions following therapy.

The aim of the present clinical trial was to evaluate the effect of different modes of periodontal therapy on patients with moderately advanced periodontal disease and to express the findings in terms of probing pocket depth and attachment level alterations at periodontal sites with different initial probing depths. The material consisted of 16 patients, 35-65 years of age. Following a Baseline examination including assessments of oral hygiene status, gingival conditions, probing pocket depths and probing attachment levels, the patients were subjected to periodontal treatment. A "split-mouth" design approach of therapy was used and the jaw quadrants were randomly selected for the following different treatment procedures: (1) scaling and root planning, (2) scaling and root planing in conjunction with a gingivectomy procedure, (3) scaling and root planing in conjunction with an apically repositioned flap procedure without bone recontouring, (4) scaling and root planing in conjunction with an apically repositioned flap procedure including bone recontouring, (5) scaling and root planing in conjunction with a modified Widman flap procedure without bone recontouring and (6) scaling and root planing in conjunction with a modified Widman flap procedure including bone recontouring. The patients were following active treatment enrolled in a supervised maintenance care program including "professional tooth cleaning" once every 2 weeks during a 6-month period of healing, after which a final examination was performed. The investigation demonstrated that active therapy including meticulous subgingival debridement resulted in a low frequency of gingival sites which bled on probing, a high frequency of sites with shallow pockets (less than 4 mm) and the disappearance of pockets with a probing depth of greater than 6 mm. Between the Baseline examination and the 6-month re-examination, the probing attachment level for initially shallow pockets remained basically unaltered, but with a tendency of a minor apical shift. This occurred in all 6 treatment groups. For sites with initial probing depths of 4-6 mm and greater than 6 mm, there was in all groups some gain of probing attachment. This gain was most pronounced in the initially deeper (greater than 6 mm) pockets. With the use of regression analysis, the "critical probing depth" (CPD) value (i.e. the initial probing depth value below which loss of attachment occurred as a result of treatment and above which gain of probing attachment level resulted) was calculated for each of the 6 methods of treatment used. A comparison of the CPD-values between the 6 treatment groups did not reveal any major differences.

Adult↗
PubMed1985

Healing following reimplantation of teeth subjected to root planing and citric acid treatment.

The aim of the present study was to examine the effect of citric acid treatment on periodontal healing around teeth which were extracted, root planed and then reimplanted. Maxillary incisors and mandibular incisors, premolars and molars of 5 monkeys were used. The teeth were divided into 3 experimental groups. In 1 group, the teeth were extracted and immediately reimplanted into their own sockets. In a 2nd group, the teeth were extracted, root planed to a level corresponding to 50-75% of the root length and then reimplanted. In the 3rd group, periodontal breakdown extending to 50-75% of the root length was first induced by placing orthodontic elastic ligatures around the teeth. They were then extracted and root planed and transplanted into the sockets of the contralateral, periodontally healthy teeth which had just been extracted. Half the number of the teeth of groups 2 and 3 were treated with citric acid before reimplantation or transplantation. The animals were sacrificed after 6 months of healing. The jaws were removed and histological specimens prepared for microscopic examination. With the exception of a limited coronal regrowth of new cementum in the apical part of the planed portion of a few roots, connective tissue attachment failed to reform on most root surfaces deprived of their periodontal ligament tissue. Healing was most frequently characterized by root resorption and ankylosis. These were the most predominant features of healing both on root surfaces which had been deprived of the ligament tissue by mechanical means or during a course of experimentally-induced periodontal disease, and occurred in citric acid as well as non-citric acid treated roots. The findings imply that the result of healing following tooth reimplantation or transplantation is determined by the type of cells that repopulate the wound area adjacent to the denuded root surface.

Animals↗
PubMed1985

Marginal tissue reactions at osseointegrated titanium fixtures.

A longitudinal prospective and a cross-sectional retrospective study were undertaken in order to investigate the marginal tissue reactions at osseointegrated titanium fixtures and their abutments, supporting fixed bridges. Conventional clinical periodontal examination methods were combined with a serial-identical radiography. At the termination of the studies samples were taken for microbiological and histological analyses. Altogether the reactions at 220 fixtures in 40 jaws were explored. The clinical parameters were not found correlated with the other examination methods. Only 0.9 mm marginal bone was lost as a mean during the first year and then not more than 0.05-0.07 mm as a mean annually for the follow-up years. A stress-related remodelling of the perifixtural bone was observed radiographically. The microbiotia in the gingival pockets was dominated by cocci and non-motile rods (94%), indicating a favourable composition if similar findings had been observed at teeth. Half the number of the biopsies had no inflammatory infiltrates and a further third had the lowest inflammatory score in a 3-grade scale. The results indicate that the soft tissue surrounding the gingival part of osseointegrated fixtures remains remarkably healthy, which, in combination with the annual minor loss of marginal bone, is an indication of good long-term clinical prognosis.

Alveolar Process↗
PubMed1984

Recession in sites with inadequate width of the keratinized gingiva. An experimental study in the dog.

The present investigation was performed to assess the inflammatory response in gingival units subsequent to the placement of restorations with subgingivally located margins. 3 beagle dogs were used. Cotton floss ligatures were placed around the neck of the mandibular third and fourth premolars of all dogs. The ligatures were exchanged once a month during the first 6 months of experiment. When 40-50% of the height of the supporting tissues had been lost in an experimental periodontitis the ligatures were removed but the animals allowed to accumulate deposits for another 60 days. The inflamed periodontal tissues were subsequently excised using either an "apically placed flap" procedure or a "gingivectomy" procedure. In the flap procedure the main part of the keratinized gingiva was preserved while in the gingivectomy procedure the keratinized part of the gingiva was removed in toto. Following scaling and root planing the animals were during a maintenance period of 4 months placed on a program involving chlorhexidine application and mechanical tooth cleaning twice daily. On Day 0 a notch was prepared in the buccal surface of each root at the level of the gingival margin. Furthermore, steel bands were placed along the buccal surface of each root of the third and fourth premolars and secured with an apical margin at the level of 1 mm apical to the notch. The bands were cemented to the root surfaces by a cement. The dogs were allowed to accumulate plaque and calculus for 6 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

New attachment formation as the result of controlled tissue regeneration.

The present study was designed to examine whether new attachment forms on root surfaces previously exposed to plaque by preventing the oral epithelium and the gingival connective tissue from participating in the process of healing following treatment. 4 roots in each of 3 monkeys were used as test units while the roots of contralateral teeth served as controls. A surgical procedure was first used to expose the coronal half of the buccal root surfaces. Plaque was allowed to accumulate on the exposed surfaces for a period of 6 months. Subsequently, soft tissue flaps were raised and the root surfaces were carefully scaled and planed. The crowns of the test and control teeth were resected and the mucosal flaps were repositioned and sutured in such a way that the roots were properly covered. Immediately prior to suturing, membranes (Millipore filter or Gore-tex membrane) were placed over the denuded root surfaces of the test teeth in order to prevent granulation tissue from the soft tissue flaps from reaching the roots during healing. The monkeys were sacrificed 3 months later. The jaws were removed and histological sections of test and control roots including their periodontal tissues were produced. New cementum with inserting collagen fibers was observed on the previously exposed surfaces of both test and control roots. However, the test surfaces exhibited considerably more new attachment than the control surfaces, indicating that the placement of the membrane favoured repopulation of the wound area adjacent to the roots by cells originating from the periodontal ligament.

Alveolar Process↗
PubMed1984

Long-term maintenance of patients treated for advanced periodontal disease.

The aim of the present investigation was to evaluate the periodontal conditions of a group of patients who, following active treatment of extremely advanced periodontal disease, had been maintained for 14 years in a well-supervised maintenance care program. The present sample included 61 subjects out of an initial group of 75 individuals who in 1969 were referred to and treated by the authors. Following an initial examination, the patients were given detailed instructions in proper plaque control measures and were subjected to scaling and root planning and surgical elimination of pathologically deepened pockets. After the termination of the active treatment phase, the patients were placed in a maintenance care program including recall appointments every 3-6 months. At the initial examination, immediately after the completion of the active treatment phase and then once a year, all patients were examined regarding oral hygiene, gingival conditions, probing depths and clinical attachment levels. In addition, the interproximal alveolar bone height was determined from full mouth radiographs obtained before active treatment, at the completion of active therapy and 1, 3, 5, 8, 10, 12 and 14 years after treatment. The results from the repeated examinations demonstrated that treatment of advanced forms of periodontal disease resulted in clinically healthy periodontal conditions and that this state of "periodontal health" could be maintained in most patients and sites over a period of 14 years. It was also demonstrated that the treatment and maintenance programs described were equally effective in young and older patients. The individual mean values describing probing depths, attachment levels, and bone heights did not vary significantly over the 14 years of observation. A more detailed analysis of the data revealed, however, that a small number of sites in a few patients lost a substantial amount of attachment. This attachment loss occurred at different time intervals during the course of the maintenance period. Thus, 43 surfaces in 15 different patients were exposed to recurrent periodontal disease of a significant magnitude. This recurrent inflammatory periodontal disease caused the loss of 16 teeth in 7 different patients during the maintenance period. The data reported question the validity of using individual mean values to describe alterations of the periodontal conditions during maintenance following active periodontal therapy.

Adult↗
PubMed1984

New concepts of destructive periodontal disease.

The most common forms of destructive periodontal disease have been thought to slowly and continuously progress until treatment or tooth loss. Recently, data have become available which are inconsistent with this "continuous disease" hypothesis. Data from longitudinal monitoring of periodontal attachment levels and alveolar bone in humans and in animals suggest that periodontal disease progresses by recurrent acute episodes. In addition, rates of attachment loss have been measured in individual sites which are faster than those consistent with the continuous disease hypothesis or slower than those expected from estimates of prior loss rates. To account for these observations, a model of destructive periodontal disease is described in which bursts of activity occur for short periods of time in individual sites. These bursts appear to occur randomly at periodontal sites throughout the mouth. Some sites demonstrate a brief active burst of destructive periodontal disease (which could take a few days to a few months) before going into a period of remission. Other sites appear to be free of destructive periodontal disease throughout the individual's life. The sites which demonstrate destructive periodontal activity may show no further activity or could be subject to one or more bursts of activity at later time periods. Comparison of monitored loss rates for a year with mean loss rates prior to monitoring suggested that there may be relatively short periods in an individual's life in which many sites undergo periodontal destruction followed by periods of extended remission. An extension of the random disease model is also suggested in which bursts of destructive periodontal disease activity occur with higher frequency during certain periods of an individual's life.

Adult↗