Biomedical subjects

T Berglundh

Publications and source records attributed to T Berglundh.

At least 55 records · Page 3Linked to original sources

PubMed1997

The mucosal barrier following abutment dis/reconnection. An experimental study in dogs.

In the present experiment, the effect on the marginal peri-implant tissues following repeated abutment removal and subsequent reconnection was studied. 5 beagle dogs were used. The mandibular premolars were extracted and 2 fixtures of the Brånemark System were installed, 1 in each mandibular quadrant. 3 months later, abutment connection was performed. A 6-month period of plaque control was initiated. Once a month during the plaque control period, the abutment of the right side (test) in each dog was disconnected, cleaned and reconnected to the failure. Thus, each test abutment was removed and reconnected altogether 5x during this period. The contralateral abutment remained undisturbed for 6 months and served as control. 1 month after the last reconnection, the animals were sacrificed and tissue samples, comprising the implant and the surrounding soft and hard peri-implant tissues, were obtained, decalcified, embedded in Epon and sectioned. The following landmarks were identified and used for linear measurements: PM (the marginal portion of the peri-implant mucosa), aJE (the level of the apical termination of the junctional epithelium), B (the marginal level of bone to implant contact), A/F (the abutment/fixture border). The findings indicate that the dis- and subsequent reconnections of the abutment component of the implant compromised the mucosal barrier and resulted in a more "apically" positioned zone of connective tissue. The additional marginal bone resorption observed at the test sites following abutment manipulation may be the result of tissue reactions initiated to establish a proper "biological width" of the mucosal-implant barrier.

Alveolar Bone Loss↗

PubMed1997

Composition of plaque-associated lesions in the gingiva and the peri-implant mucosa in partially edentulous subjects.

The purpose of the present investigation was to study characteristics of the plaque associated lesions in the gingiva and the adjacent periimplant mucosa sampled from the same subjects. 20 partially edentulous patients (12 female and 8 male, 30-60 years of age) volunteered to participate in the study. They had all been treated for moderate to advanced periodontal disease. Edentulous regions had been restored with implants. The restorative therapy had been completed 6-24 months prior to soft tissue biopsy. Samples of gingival tissue (GM) and periimplant mucosa (PIM) from an "interproximal surface" of one tooth site and one implant site of the same jaw were harvested. One portion of the biopsy was embedded in EPON, stained in PAS and toluidine blue and used for histometric and morphometric analyses. The 2nd portion of the biopsy was snap frozen in liquid nitrogen. 15 sections, about 5 microns thick, were prepared in a cryostat and used for immune histochemical staining. The analysis of the sections included determination of the size of the lesions as well as assessments of various cells and cell markers. In all samples of both PIM and GM discrete infiltrates of inflammatory cells (ICT) were found in the connective tissue lateral to the junctional epithelium. The ICT of PIM occupied on the average 0.17 +/- 0.14 mm2 of the soft tissue, while the corresponding lesion in GM occupied an area that was 0.25 mm2 +/- 0.21 mm2 large. The density of CD19 positive cells was 7 times higher in GM than in PIM (3.7 versus 0.5) while the densities of CD3 positive cells were 7.5 (GM) and 4.7 (PM) respectively. The density of PMN elastase positive cells was about 3 times higher in GM than in PIM (3.7 versus 1.2). Care must be exercised when these differences are interpreted. It is possible that a prolonged exposure of the implant site to the oral environment may induce both qualitative and quantitative changes of the infiltrate in PIM.

Adult↗

PubMed1997

Tissue characteristics of root resorption areas in transplanted maxillary canines.

The aim of the present study was to describe some histopathologic features of tissues collected from root resorption areas of maxillary canines after transalveolar transplantation surgery. In 8 of 101 transplanted canines, complications including cervical root resorption occurred between 6 and 11 years after treatment. The resorptive processes were located at the supra-alveolar portions of the distal and/or mesial aspects of the teeth and were scheduled for treatment involving surgical exploration. The resorption cavities, which extended from the cementoenamel junction to a position immediately below the bone crest, were filled with a granulation tissue. In four of the diagnosed complication cases, this granulation tissue was carefully excised concomitant with the adjacent gingival tissue after flap elevation and placed in a buffered fixative. After proper soft-tissue healing, the cavities were filled with a glass-ionomer material. The collected biopsy specimens were, after fixation and, in one case, decalcification in ethylenediaminetetraacetic acid, dehydrated and embedded in Epon. Sections 3 microns thick were produced, stained in periodic acid-Schiff and toluidine blue, and used for histometric and morphometric analyses. The histologic analysis showed that the dissected tissue harbored well-encapsulated areas of inflammatory infiltrates. The lesions comprised a relatively low volume of collagen and a large number of inflammatory cells, predominantly lymphocytes.

Adult↗

PubMed1996

The peri-implant hard and soft tissues at different implant systems. A comparative study in the dog.

The aim of this study of the present experiment was to study the marginal periimplant tissues at intentionally non-submerged (1-stage implants) and initially submerged and subsequently exposed implants (2-stage implants). 5 beagle dogs, about 1-year-old, were used, 3 months after the extraction of the mandibular premolars, fixtures of the Astra Tech Implants Dental System, the Brånemark System and the Bonefit--ITI system were installed. In each mandibular quadrant, 1 fixture of each implant system was installed in a randomised order. The installation procedure followed the recommendations given in the manuals for each system. Thus, following installation, the bone crest coincided with the fixture margin of the Astra Tech Implants Dental System and the Brånemark System, whereas the border between the plasma sprayed and the machined surface of the Bonefit-ITI implant system was positioned at the level of the bone crest. Following a healing period of 3 months, abutment connection was carried out in the 2-stage systems (the Astra Tech Implants Dental System and the Brånemark system). A 6-month period of plaque control was initiated. The animals were sacrificed and biopsies representing each important region dissected. The tissue samples were prepared for light microscopy and exposed to histometric and morphometric measurements. The mucosal barrier which formed to the titanium surface following 1-stage and 2-stage implant installations comprised an epithelial and a connective tissue component, which for that 3 systems studied, had similar dimensions and composition. The amount of lamellar bone contained in the periimplant region close to the fixture part of the 3-implant systems was almost identical. It is suggested that correctly performed implant installation may ensure proper conditions for both and hard tissue healing, and that the geometry of the titanium implant seems to be of limited importance.

Alveolar Process↗

PubMed1996

The effect of antimicrobial therapy on periimplantitis lesions. An experimental study in the dog.

The objective of the present study was to evaluate the effect of systemic antibiotics and local debridement in the treatment of experimentally induced periimplantitis lesions. 5 Labrador dogs, and about 1-year old, were included in the study. In order to establish bilateral recipient sites for implants the mandibular right and left 1st molars, 4th and 3rd premolars were removed. 6 titanium fixtures (Brånemark System Nobelpharma AB, Göteborg, Sweden) were installed and standard abutments were connected 3 months after fixture installation. Cotton floss ligatures were placed in a submarginal position around the neck of the abutments and the animals were placed on a diet which allowed plaque accumulation. After 6-8 weeks, when the tissue destruction amounted to about 20% of the fixture length, the ligatures were removed. 1 month after ligature removal, an antibiotic regimen (amoxicillin and metronidazole) was initiated and maintained for 3 weeks. In the left side of the mandible, buccal and lingual mucoperiosteal flaps were elevated, the granulation tissue within the bone craters adjacent to the implants was curetted, and the abutments were removed. The exposed outer surface, the internal part of the fixtures, as well as the abutments were treated with a detergent, delmopinol. The cleaned abutments were autoclaved, and connected to the clean fixtures. The mucoperiosteal flaps were replaced to their original position, adapted to the abutments and sutured. A careful plaque control program was initiated for the left jaw quadrants. In the right side of the mandible no local treatment was given to the fixtures and the abutments following ligature removal. Furthermore, no plaque control was provided to the implant segments in the right jaws. After 4 months of healing block biopsies including one implant with adjacent hard and soft tissue were harvested and prepared for light microscopy. It was observed that systemic antimicrobial therapy, combined with implant cleaning, curettage of the bone defect and regular plaque control resulted in (i) resolution of the periimplantitis lesion, (ii) a significant recession of the marginal periimplant mucosa, and (iii) a minor additional apical shift of the base of the bone defect. In the untreated sites the plaque associated infiltrate remained and was in several sites examined in contact with the adjacent bone tissue.

Amoxicillin↗

PubMed1996

Guided bone regeneration in the treatment of periimplantitis.

The objective of the present experiment was to study the soft and hard tissue healing following treatment of experimentally induced periimplantitis. 5 labrador dogs about 1-year old were used. The mandibular right and left 1st molars, 4th and 3rd premolars were removed, titanium fixtures (Brånemark System) were installed, and standard abutments were connected in a 2nd stage procedure. After 3 months experimental periimplantitis was induced by the placement of cotton floss ligatures in a submarginal position. 6 weeks later the ligatures were removed. 1 month after ligature removal, an antibiotic regimen was initiated. During a 3-week period, each dog was given tablets of amoxicillin and metronidazole. In the left side of the mandible, buccal and lingual mucoperiosteal flaps were elevated and granulation tissue within the bone craters curetted. The abutments were removed. The exposed outer surfaces and the internal part of the fixtures were carefully cleaned with a detergent (delmopinol HC1). An e-PTFE membrane was placed over each fixture and adjusted to cover the bone crater. New cover screws were fitted through the membranes to the cleaned fixtures. The implants were submerged and the flaps sutured. In the right side of the mandible no local treatment was performed. The dogs were sacrificed after 4 months and biopsies prepared for histological examination. The findings indicated that treatment of a periimplantitis lesion, including comprehensive systemic antimicrobial therapy and cleaning of submerged implants resulted in (i) the elimination of the inflammatory process in the periimplant tissues and (ii) the establishment of a dense connective tissue capsule in direct contact with the previously exposed surface of the implant system. It was also observed that (iii) new bone was frequently laid down on the pristine cover screws.

Animals↗

PubMed1996

Dimension of the periimplant mucosa. Biological width revisited.

The objective of the present study was to determine the dimension of the mucosal-implant attachment at sites with insufficient width of the ridge mucosa. 5 beagle dogs were used. Extractions of all mandibular premolars were performed and 3 months later, 3 fixtures of the Branemark System were installed in each side. Following 3 months of healing, abutment connection was carried out. On the right or left side of the mandible, abutment connection was performed according to the Branemark System manual (control side). On the contralateral side (test side), an incision not extending through the periosteum was made at the crest of the ridge. The soft tissue was dissected and a critical amount of connective tissue on the inside of the flap was excised. The periosteum was subsequently incised, abutment connection performed, and the trimmed flaps sutured. The sutures were removed after 10 days. After a 6-month period of plaque control, the animals were sacrificed, biopsies sampled and processed for light microscopy. The length of the junctional epithelium varied within a rather narrow range; 2.1 mm (control side) and 2.0 mm (test side). The height of the suprabony connective tissue in this model varied between 1.3+/-0.3 mm (test side) and 1.8+/-0.4 mm (control side). At sites where the ridge mucosa prior to abutment connection was made thin (< or = 2 mm), wound healing consistently included bone resorption. This implies that a certain minimum width of the periimplant mucosa may be required, and that bone resorption may take place to allow a stable soft tissue attachment to form.

Alveolar Process↗

PubMed1996

Some characteristics of the ridge mucosa before and after implant installation. A prospective study in humans.

The aim of the present investigation was to study some tissue characteristics of the ridge mucosa before and after implant installation. 9 partially edentulous patients were included in the study. At the time of fixture installation, 1 recipient site in each patient was selected for soft tissue biopsy. Abutment connection and restorative therapy were performed after 3-6 months. When the implants had been in function for about 6 months, a soft tissue sample was obtained from the keratinized peri-implant mucosa at the 1 implant site from which the first biopsy was obtained. Each biopsy was divided into 1 mesial and 1 distal portion. The mesial tissue portion was fixed in a buffered fixative and embedded in EPON. Sections were produced, stained in PAS and toluidine blue and used for histometric and morphometric analyses. The distal portion of the biopsies were embedded, snap frozen in liquid nitrogen and stored in a freezer at -70 degrees C. From each tissue portion, 15 sections were prepared in a cryostat and exposed to immunohistochemical staining. A panel of monoclonal antibodies was used and the avidin-biotin method for staining was applied. The sections were examined morphometrically. Both tissues harbored a well keratinized oral epithelium and a connective tissue, the composition of which was close to identical in terms of collagen, cells and vascular structures. The peri-implant mucosa, however, also included a junctional epithelium which evidently allowed the penetration of products from the oral cavity. As a consequence, the periimplant mucosa in comparison to the masticatory mucosa was found to contain significantly enhanced numbers of different inflammatory cells.

Adult↗

PubMed1996

The effect of age on the development of gingivitis. Clinical, microbiological and histological findings.

In the present "experimental gingivitis" study, the response of the marginal gingiva to plaque formation was studied in one group of young subjects, 20-25 years of age, and in one group of older subjects, aged 65-80 years. During a 4-week period, all subjects received a series of professional tooth cleaning to establish healthy gingival conditions. A baseline examination (Day 0) included assessments of plaque and gingivitis. Sites that were examined (the experimental sites) included the mesio-palatal, palatal, and disto-palatal surfaces of all teeth present in the 15 ... 25 tooth region. Among the experimental sites, microbial sampling and gingival fluid assessment were performed and one gingival biopsy harvested from each subject. Following the baseline examination, the participants abolished mechanical tooth cleaning measures in the palatal and approximal surfaces of 15 ... 25. The clinical examination and the gingival fluid measurement were repeated on days 7, 14 and 21 of no oral hygiene. The microbiological sampling and the biopsy procedure were repeated on days 7 and 21. The data collected demonstrated that old subjects, during a 3-week period of oral hygiene abstention, formed similar amounts of plaque as the young subjects, but developed more gingivitis than young subjects. Thus, the clinical gingivitis assessments, the gingival fluid measurements and morphometric determinations made in the biopsy samples documented that the gingival lesion which formed in the old individuals was more pronounced and contained more inflammatory cells than the corresponding lesion in the young subject sample.

Adult↗

PubMed1996

Effects of cyclosporine A on plasma cells in experimental gingivitis in dogs.

The aim of the present investigation was to evaluate the effect of Cyclosporine A (CsA) on the inflammatory lesion formed in the gingival tissues during de novo plaque formation. 5 beagle dogs were used. On day 0, all teeth of the 5 dogs were scaled and polished. A 6-week period of plaque control including daily tooth cleaning with toothbrush and dentifrice was initiated. A clinical examination regarding plaque and gingivitis was performed, and the plaque control measures were abandoned on the right side of mandible. 3 weeks later, the clinical examination was repeated, samples of subgingival plaque harvested and biopsies obtained from the 3rd and 4th right mandibular premolar regions. The tooth cleaning measures on the left side of the mandible were terminated at this interval. During the following 3 weeks, the animals formed plaque in the lower left premolar regions, and received, 1 x daily, a subcutaneous injection of CsA. At the end of this 2nd plaque formation period (test), the clinical examination was repeated, subgingival plaque was sampled and biopsies from the 3rd and 4th left mandibular premolar regions harvested. The biopsies were prepared for histometric and morphometric analyses. The clinical and histological examinations demonstrated that plaque formation resulted in a gingival lesion (ICT) which, in the 2 periods, had similar size and apical extension. The ICT formed during the CsA administration period, however, harbored an increased number of plasma cells and a reduced macrophage density than the control lesion. It is suggested that CsA administration may result in a Th-2 (T-helper 2-cell) dependent activation of B-lymphocytes.

Aggregatibacter actinomycetemcomitans↗

PubMed1996

The periodontal tissues in healed degree III furcation defects. An experimental study in dogs.

The aim of the present study was (i) to describe the periodontal tissue that formed in degree III furcation defects in mandibular molars of dogs following GTR therapy and (ii) to compare this healed periodontium to the corresponding tissue of pristine furcations. The study was performed in 10 mongrels dogs. In 6 of the dogs (group A), the 2nd and 4th premolars in both sides of the mandible were extracted 2 months prior to the start of the study. The 4 remaining dogs (group B) were used as normal untreated controls. In the dogs of group A, a furcation defect was produced in the 3rd mandibular premolars and reconstructive surgery was later performed in accordance with the GTR technique. 5 months after reconstructive surgery, all 10 animals (groups A+B) were sacrificed and perfused with a solution of 10% neutral, buffered formalin through the carotid arteries. Tissue blocks containing the experimental teeth were excised, demineralized in EDTA, embedded in paraffin. Serial sections were cut in the mesiodistal plane and parallel with the long axis of the roots. The microtome was set at 7 microns. The sections were stained in hematoxyline and eosin or Van Gieson's connective tissue staining. From each biopsy, 3 sections, 14 microns apart, and representing the central part of the furcation, were selected for light microscopic examination. In the healed furcation sites, histometric and morphometric measurements were performed at different levels (zones), either at the mesial or distal root surfaces; (zone 1) immediately apical of the notch; (zone 2) coronal to the notch where the newly formed alveolar bone was in continuity with the reduced bone crest; (zone 3) coronal to the notch; representing the most coronally positioned area of new bone formation; (zone 4) coronal to the notch; representing areas with no alveolar bone present. In the pristine furcation sites, the measurements were made at zones which corresponded to the location of the zones in the healed furcations. The present data demonstrated that all furcation sites in group A after 5 months of healing exhibited comprehensive de novo cementum formation in the previously exposed parts of the intraradicular root surfaces, and that collagen fibers invested in the newly formed cementum. Comparisons between the pristine and the healed furcations disclosed that the periodontal ligament of the healed furcations was poorly organised, and that bone formation was frequently incomplete.

Alveolar Process↗

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

The effect of flap management and bioresorbable occlusive devices in GTR treatment of degree III furcation defects. An experimental study in dogs.

The present experiment on guided tissue regeneration had 2 objectives namely: (i) to study if an improved anchorage of the soft tissue flaps during the initial healing period after membrane placement would reduce the tendency for soft tissue recession and allow for healing of also large furcation defects; (ii) to determine if the use of biodegradable membranes in GTR procedures may promote new attachment formation in degree III furcation defects. 2 experiments were performed which included 5 and 8 dogs each. In each animal, the 3rd premolar of the left or right side of the mandible was selected as test site using the contralateral tooth as control. 2 months prior to the start of the experiment, the 2nd and 4th premolars in each side of the mandible were extracted. The extractions were performed to create a large edentulous space mesial and distal to the 3rd premolar. During GTR therapy the incisions prepared in this edentulous region were used to allow proper suture retention and flap stability during the initial phase of healing. In study 1, furcation defects (degree III) were prepared and subsequently treated according to GTR using e-PTFE membranes in the test and no membrane in the control site. In study 2, a bioresorbable membrane (Resolut) was installed in the test and an e-PTFE membrane in the control sites. The non-resorbable membranes were removed after 30 days. The animals were sacrificed 5 months after reconstructive surgery, biopsies were harvested, sectioned and analyzed histologically for new connective tissue attachment and bone.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Process↗

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↗

PubMed1994

The topography of the vascular systems in the periodontal and peri-implant tissues in the dog.

The present investigation reports an animal experiment the objective of which was to study the vascular topography of the periodontium and the peri-implant soft and hard tissues in the beagle dog. 2 beagle dogs were used. The right mandibular premolars were extracted and healing allowed for 3 months. 2 titanium fixtures a.m. Brånemark were installed in the right premolar region. Abutment connection was performed 3 months later. The contra-lateral mandibular sites were used as tooth harboring control units. A 4-month period of meticulous plaque control was initiated. A clinical and radiographical examination was performed towards the end of this period and revealed that the gingiva and peri-implant mucosa were clinically healthy and that the bone tissue at teeth and implants had a normal height. The carotid arteries were perfused with a mixture of carbon and calf serum. 2 bucco-lingual sections, about 100-150 microns thick, and one mesio-distal section comprising the junctional epithelium and underlying connective tissue were sampled. The sections were treated, cleared and examined in a microscope. The results of the present investigation demonstrated that the vasculature of the gingiva and the supracrestal connective tissue at teeth is derived from two sources, namely the supraperiosteal vessels lateral of the alveolar process and the vessels of the periodontal ligament. The blood vessels of the peri-implant mucosa were found to be terminal branches of larger vessels originating from the periosteum of the bone of the implant site.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Tooth mobility and resolution of experimental periodontitis. An experimental study in the dog.

The aim of the present experiment was to study alterations in the mobility of teeth that occurred during resolution of experimentally induced periodontitis lesions in the dog. 5, 1-year-old, beagle dogs were used in the study. The left and right 4th, 3rd, and 2nd mandibular premolars (4P4, 3P3, 2P2) served as experimental teeth. Periodontal tissue breakdown was initiated by placing plaque-collecting cotton-floss ligatures around the neck of the experimental teeth. The ligatures were replaced to the level of the receding gingival margin 1 x every month. On Day 120, the ligatures were removed and debridement was performed. A groove, parallel to the long axis of the mesial root, was prepared in the mesio-buccal surface of the crowns of 2P and P2. Guided by the groove and with a probing force of 0.5 N, a probe was inserted into the buccal gingival pocket of the mesial root and was attached to the buccal surface. Biopsies including both the mesial and distal root of 2P and P2 and the surrounding hard and soft tissues were harvested. The biopsy procedure was repeated in a similar manner 15 days (i.e. Day 135) and 3 months (i.e. Day 225) after ligature removal in the 4th (4P4) and 3rd (3P3) premolar regions. After fixation, decalcification and sectioning, the biopsy material was exposed to histometric and morphometric measurements. Assessment of the mobility of the experimental teeth was performed on Days 120, 135 and 225 using the Periotest system.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Bone Loss↗

PubMed1994

Epithelial remnants in the crestal periodontium of the deciduous and permanent dentition of beagle dogs.

The purpose of this study was to document and characterize epithelial remnants (EPRs) of the crestal periodontium of the deciduous dentition of a diphyodont and compare them with EPR units found in the corresponding area of the permanent dentition. 7 beagle dogs were used. At the age of 10 weeks (deciduous dentition) and 15 months (permanent dentition), respectively, a 6-week plaque control period was initiated. At the end of each plaque control period, biopsies were obtained from the mandibular 02P, 03P (deciduous dentition) and P3, P4 (permanent dentition) premolar regions and prepared for histologic analysis. 2 regions, (1) the supracrestal region and (2) the periodontal ligament region, were identified. The supracrestal region was divided into 4 compartments of equal height. The histologic parameters studied included the (i) EPR frequency: number of EPRs/mm of root length, (ii) EPR size, (iii) EPR-root distance, (iv) EPR-bone distance and (v) cell area. No differences were observed between the 2 dentitions with respect to the number, size and relative location of EPR units in the supracrestal regions or the periodontal ligament regions. Epithelial remnants of the supracrestal region in both dentitions tended to be more frequent, larger and positioned further from the root surface than the EPRs of the periodontal ligament region. EPR units of the periodontal ligament region were located significantly further from the bone in the deciduous dentition than in the permanent dentition. The cell area of EPRs did not differ between the 2 dentitions.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Process↗

PubMed1994

Some microbiological, histopathological and immunohistochemical characteristics of progressive periodontal disease.

The aim of the present investigation was to study the local nature of human periodontal disease by assessing the microbiota and the composition of the tissue lesions at sites with progressive attachment loss in periodontitis susceptible subjects. 300 subjects with periodontal disease were monitored for 2 years without treatment. 8 subjects lost > 2 mm of attachment at > or = 3 sites during both the first and the second 12 month interval. These 8 subjects (progressive disease group; PD) were recalled for a microbiological and histopathological examination. A group of age- and sex-matched subjects were identified who during the 2 years of monitoring exhibited gingivitis and deep pockets, but no further attachment loss. This group of 11 subjects (non-progressive disease group; NPD) served as controls. From the 8 active disease subjects, > or = 1 interproximal site which had displayed disease activity (progressive disease active; PDA) and > or = 1 contralateral site without disease progression (progressive disease inactive; PDI) were sampled. From the 11 control subjects, 1 site/subject was sampled (NPD). The total number of viable micro-organisms (TVC) in the subgingival microbiota was estimated and a series of bacterial species were identified and enumerated. The gingival tissue of the sampling site was excised and the soft tissue prepared for morphometrical and immunohistochemical analyses. No differences were observed in the subgingival microbiota of the sample sites in the subjects who exhibited disease progression (PD) when compared with the subjects with periodontally diseased but stable conditions (NPD).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗