Biomedical subjects

J Lindhe

Publications and source records attributed to J Lindhe.

At least 91 records · Page 5Linked to original sources

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

The periodontal ligament of teeth connected to osseointegrated implants. An experimental study in the beagle dog.

The aim of the present investigation was to analyze the periodontal tissues at immobilized teeth connected to osseointegrated implants. 10, 1-year old beagle dogs, were used. Bilaterally, the mandibular 2nd (2P2) and 3rd premolars (3P3) and 1st molars (1M1) were extracted. 2 titanium fixtures were installed in the edentulous segment of the right side of the mandible, one about 10 mm mesial and the other about 10 mm distal to 4P (test tooth). 3 months later, abutment connection was performed and healing allowed for one month. The dogs were randomly divided into 2 groups of 5 each, group A and group B. In group A, a fixed gold splint, rigidly connecting the tooth and the 2 implants, was installed on day 0 and 4P was hereby immobilized. The controlateral 4th premolar (P4) served as the non-splinted control tooth. Plaque control measures continued until the end of the experiment (day 180). In group B, plaque control measures were abandoned 1 month after abutment connection and a 4- month period of experimental periodontal tissue breakdown was initiated. This was accomplished by placing cotton floss ligatures submarginally around 4P and P4. At the end of this 4-month period, the ligatures were removed, and an apically positioned flap procedure was performed. Healing was allowed for another 2 months. Plaque control measures were re-established and continued throughout the experiment. A given day was termed day 0 and 4P was rigidly connected to the adjacent implants in the manner described for group A.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Process↗

PubMed1995

A radiographic survey of periodontal conditions in Greece.

The present study used radiographic assessments to evaluate the pattern of destructive periodontal disease ina rural and an urban sample of 25-64 year old Greek adults. The rural sample (A) comprised 190 subjects and the urban sample (B) 400 subjects. 13% of the subjects in sample A and 8% in sample B were edentulous. Full-mouth intraoral radiographs were obtained from the 503 dentate subjects and were examined with respect to (i) number and type of teeth present, and (ii) alveolar bone level (ABL), i.e., the distance between the cementoenamel junction and the alveolar bone crest at the approximal tooth surfaces. The results revealed that alveolar bone loss was ubiquitous in both samples. Pronounced bone loss, however, (i.e., a subject mean ABL of > or = 6 mm) affected 18% (sample A) and 8% (sample B) of the individuals. Although an ABL of > or = 6 mm was scored at 7.2 sites/subject in sample A and at 4.5 sites/subject in sample B, more than 10 such sites were found in 23% (A) and 11% (B) of the examined subjects. 25% of the subjects in the rural sample (A) and 12% in the urban sample (B) accounted for 75% of the total number of tooth sites with pronounced bone loss. Multiple regression revealed that age and number of remaining teeth were the parameters most strongly correlated with the amount of bone loss on both the individual subject and the tooth site level. The present findings (i) demonstrated a high prevalence and severity of destructive periodontal disease in these 2 samples. and (ii) confirmed the skewed distribution of advanced disease in the population.

Adult↗

PubMed1995

The effect of triclosan on developing gingivitis.

The aim of the study was to examine whether triclosan has an effect on developing gingival inflammation. 10 volunteers, with clinically healthy gingivae were enrolled. The study was performed as a 2-week, double-blind, cross-over, experimental gingivitis trial. Between each plaque accumulation period, there was a wash-out phase of 4 weeks. A baseline examination was performed which included assessment of plaque and gingivitis. The volunteers were asked to refrain from mechanical oral hygiene measures for 2 weeks. During this period, they rinsed 2x daily with one of the randomly assigned mouthrinse preparations. Solution A (period A): 0.06% triclosan+ 2%tween 80. Solution B (period B): 0.06% triclosan+ 0.25% sodium lauryl sulphate. Re-examinations were performed on days 4, 7, 11 and 14. The mean plaque score increased during period A to 2.2 (day 4), 2.8 (day 7), 3.1 (day 11) and 3.1 (day 14). The corresponding scores for period B were significantly lower; 1.2 (day 4), 1.8 (day 7), 2.0 (day 11) and 2.2 (day 14). The mean gingivitis scores at baseline were 0.17 (periods A and B). The mean gingivitis scores increased to 0.45 (day 4), 0.69 (day 7), 0.83 (day 11) and 0.96 (day 14) when the subjects rinsed with solution A and 0.42 (day 4), 0.64 (day 7), 0.78 (day 11) and 0.92 (day 14) in period B. There were no statistically significant differences between periods A and B with respect to gingivitis. Thus, although significantly more plaque formed during period A than period B, no differences could be found between the gingivitis scores in the 2 periods.

Adult↗

PubMed1995

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

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

Alveolar Bone Loss↗

PubMed1995

Guided tissue regeneration in the treatment of degree II furcations in maxillary molars.

he present clinical trial was designed to evaluate the clinical effect of GTR in the treatment of degree II furcation defects in maxillary molars. 28 patients, 21 to 59 years of age, referred for treatment of advanced periodontal disease were included. They presented with similar periodontal lesions in the right and the left maxillary molar regions, but had only one surface which exhibited furcation involvement. A total of 28 pairs of contralateral furcation defects of degree II including 18 interproximal pairs (10 mesial, 8 distal) and 10 buccal pairs, were available for the study. After the completion of basic therapy, the furcation involved molars in the right and left quadrants in each patient were randomly assigned to either a test or a control treatment procedure. Following flap elevation, scaling, root planing and granulation tissue removal, an e-PTFE membrane at the test site was adjusted to cover the entrance to the furcation defect and adjacent bone and was retained in this position with sling sutures. The mucoperiostal flaps were subsequently adjusted and positioned to cover the entire surface of the membrane and were secured in this position. An identical surgical procedure was performed in the control tooth regions with the exception of the placement of a teflon membrane. No periodontal dressing was used. Starting the day before surgery and continuing for 7 days, the patients received 1 + 1 g of Amoxicillin per day; morning and evening. The sutures were removed after 10 days. At the test sites, the membranes were removed after 6 weeks of healing. The treated sites were examined and re-entry procedures performed 6 months after reconstructive surgery. Open flap debridement at maxillary furcations of degree II resulted in some gingival recession and probing depth reduction, but no change occurred in parameters describing probing attachment or bone levels. The addition of GTR at buccal furcations enhanced the treatment result by promoting probing attachment and bone gain and reduced the amount of soft tissue recession above what was accomplished by flap debridement alone. No such benefit of membrane therapy was observed at mesial and distal furcations.

Adult↗

PubMed1995

Periodontal ligament tissue reactions to trauma and gingival inflammation. An experimental study in the beagle dog.

The aims of the present study were to analyze (i) which tissue changes may occur in the zone of co-destruction to better understand why trauma from occlusion may induce additional attachment loss, and (ii) whether changes occur in the periodontal ligament tissue when an inflammatory lesion (ICT) approaches the periodontal ligament space. 16, 1-year-old beagle dogs, were selected and divided into 2 groups, group A and group B, consisting of 6 and 10 dogs, respectively. In group A, on day 0, a bucco-lingual jiggling type movement was induced resulting in increasing tooth mobility at P3 (test tooth) by the application of an orthodontic elastic which traversed the buccal surface of the crown of the test tooth. The elastic was exchanged either in a buccal or in a lingual position 2x a week during a 3-month period. 3P served as non-jiggled control tooth. Tooth mobility measurements were recorded on days 0, 30, 60, 90. A plaque control regimen was maintained until the end of the experiment (day 90). On day 90, biopsies including P3 and 3P were harvested. The dogs representing group B, were divided into 2 subgroups of 5 each, group BI and group BII. On day 0, a 4-month period of experimental periodontal tissue breakdown was initiated by placing cotton floss ligatures submarginally around the mandibular fourth premolars (4P4) in group BI and around the mandibular third premolars GP3) in group BII. All ligatures were exchanged, replaced 1x every month, and on day 120 permanently removed. On the same day, biopsies included 4P4 were harvested. Following supragingival debridement 3P3 were allowed to accumulate plaque until the end of the study (day 225). On this occasion, biopsies including 3P3 were harvested. The results of the histological measurements revealed that in the most coronal portion of the periodontal ligament of teeth exhibiting increasing mobility, there was an increased width, a reduced % tissue volume of collagen, and an increased volume of vascular structures and leukocytes. Furthermore, the number of osteoclasts bordering this portion of the alveolar bone was increased and the number of collagen fibers inserting into the root cementum and into the alveolar bone was reduced. It was also demonstrated that in teeth with normal mobility, the position of the gingival ICT failed to influence the composition of the tissue within the coronal portion of the periodontal ligament.

Alveolar Process↗

PubMed1995

Guided tissue regeneration in the treatment of degree III furcation defects in maxillary molars.

11 subjects with generalized periodontitis and advanced lesions in the maxillary molar regions, including bilateral mesial-distal, but not buccal, degree III furcation defects in the 1st and/or 2nd molars, were recruited for the present clinical trial. The patients were given oral hygiene instruction and full-mouth scaling and root planing. A re-examination was performed after 3 months of healing, after which the furcation involved molars were randomly selected for a GTR or conservative treatment modality. An informed consent form was signed by each participating patient. The GTR procedure involved the elevation of mucoperiostal flaps, root surface debridement, and the placement of an e-PFTE membrane at the 2 entrances of the furcation defect. The flaps were repositioned and secured. The contralateral molar was treated in an identical manner but without the placement of the teflon membrane. The patients received amoxicillin (1g x 2/day for 8 days), were placed on chlorhexidine mouth rinsing and were recalled for prophylaxis 1x every 2 weeks. The teflon membranes were removed at a 2nd stage procedure after 6 weeks. All subjects were re-examined 6 months after the regenerative procedure, and in addition, all sites were evaluated following a reentry procedure. The final examination and measurements made during the reentry procedure documented that, although some reduction in probing pocket depth and some gain in probing attachment had occurred at both test and control sites, none of the furcation defects had closed, but retained the characteristics of a degree-III furcation involvement.

Amoxicillin↗

PubMed1995

Plaque formation at healthy and inflamed gingival sites in young individuals.

The present investigation was performed to evaluate the influence of gingivitis on the amount of de novo plaque that forms during a 24-h period of no oral hygiene. 292 fully dentate subjects participated in the study. The condition of the gingiva and the presence of supragingival plaque were examined at 4 surfaces of each tooth at a baseline examination. Following this examination, the participants were subjected to a comprehensive mechanical tooth cleaning and instructed to refrain from tooth cleaning measures during the subsequent 24 h. The plaque examinations were repeated at the end of the 24-h period. The results from the clinical trial revealed that during a 24-h period of no tooth cleaning, subjects with naturally occurring overt gingivitis, in general, formed more plaque than young individuals with healthy gingivae. Furthermore, plaque in all parts of the dentition, formed more frequently on tooth surfaces adjacent to sites with gingivitis than at healthy sites. It was concluded that the condition of the gingiva plays an important role for de novo plaque formation.

Adolescent↗

PubMed1994

Clinical and radiographical features of submerged and nonsubmerged titanium implants.

A clinical and radiographical study was performed to evaluate whether initial submergence of titanium fixtures is an obligate treatment measure for the establishment of proper bone anchorage when implants a.m. Brånemark are used. The sample was comprised of 11 subjects with edentulous mandibles. A split-mouth design was employed; in the right mandibular quadrant a traditional 2-step procedure for fixture installation and abutment connection was utilized, while in the left quadrant a 1-step procedure was carried out, i.e., fixtures were placed and abutments were connected in one and the same session. Three to 4 months after fixture installation, fixed bridgeworks were fabricated and rigidly connected to the implants. Clinical examinations (including probing pocket depth, bleeding on probing and implant stability test) were performed after 12 and 18 months. Radiographs were taken following insertion of the bridges and at the 12- and 18-month re-examinations. The probing pocket depth, the bleeding on probing, the implant stability and the radiographic determinations were similar for the 2 groups of treatment alternatives. This indicates that titanium fixtures a.m. Brånemark can be properly anchored (osseointegrated) in mandibular bone and successfully used for bridge retention also when a 1-step procedure is used for implant installation.

Adult↗

PubMed1994

The influence of gingival inflammation on de novo plaque formation.

The aim of the present clinical trial was to examine the influence of gingival inflammation on de novo plaque formation. In addition, the effect of a varying number of salivary bacteria on early plaque formation was evaluated. 10 subjects were recruited for the trial which was designed to establish 2 different starting points for de novo plaque formation, 1 in a healthy dentition and 1 in a gingivitis dentition. On Day 0 and at regular intervals during a 5-week period, the panelists were examined with respect to gingivitis, plaque and number of salivary bacteria. The findings from the study demonstrated that the condition of the marginal gingiva plays an important role in the early stages of plaque formation. Thus, in both phases of the study, it was observed that at sites with initially healthy gingival units, less plaque formed (PlI = 0.93 and 0.82) than at sites with GI > 0 (PlI = 1.24 and 1.28) at the 2 different starting points. The number of salivary bacteria seemed to be less important than the state of the gingiva for the amount of plaque that formed during a 4-day period of no active mechanical tooth cleaning.

Adult↗

PubMed1994

The prevalence and distribution of gingival recession in subjects with a high standard of oral hygiene.

The aim of this study was to evaluate the prevalence and the development/progression of attachment loss and gingival recession at buccal tooth surfaces in a population sample with a high standard of oral hygiene. An additional aim was to study the relationship between attachment loss and gingival recession. The subject sample examined comprised 225 regular dental care attendants at 12 community dental clinics in Sweden. All subjects were subjected to a baseline examination in 1977-78 and were re-examined after 5 years and 12 years. The clinical examinations involved assessment of plaque, gingivitis, probing depth, probing attachment loss and gingival recession. A full-mouth set of intraoral radiographs was obtained at each examination and used for determination of the height of periodontal bone support. The results of the cross-sectional and longitudinal analyses performed showed that in subjects with a high standard of oral hygiene (i) buccal gingival recession was a frequent finding, (ii) the proportion of subjects with recession increased with age, (iii) the prevalence as well as the incidence of recessions within the dentition showed different patterns depending on age, (iv) sites with recession showed susceptibility for additional apical displacement of the gingival margin and (v) loss of approximal periodontal support was associated with gingival recession at the buccal surface.

Adolescent↗

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

Plaque and gingivitis in the deciduous and permanent dentition.

The aim of the present investigation was to monitor de novo plaque formation and associated alterations of the gingival conditions in the deciduous, mixed and permanent dentition in man. 31 volunteers, divided into 3 study groups participated in the trial. Group 1 was made up of 11 subjects, 4-6 years of age (deciduous dentition), group 2 comprised of 10 subjects, 8-9 years of age (mixed dentition) and group 3 included 10 subjects, 14-16 years of age (permanent dentition). After a screening examination, each participant received detailed instruction in a proper oral hygiene technique and was subjected to professional tooth cleaning. The professional debridement and the oral hygiene instruction were repeated after 1 week. After another week, a given day was termed Day 0 and a baseline examination was performed. This examination included assessments of plaque and gingivitis. Each subject received an additional, comprehensive professional tooth cleaning and was asked to abstain from all mechanical oral hygiene measures. Re-examinations were performed after 3 and 7 days. The findings demonstrated that: (i) during a 7-day period of no active oral hygiene, subjects with a mixed or a permanent dentition formed visible amounts of plaque and developed modest signs of gingivitis; (ii) during the 7 days of the trial, young subjects with a fully erupted deciduous dentition formed less plaque than the older subjects, and failed to respond to de novo plaque formation with enhanced signs of gingivitis; (iii) in subjects with a mixed dentition, the amount of plaque formed during the 7 days of experiment and the matching gingivitis development were similar in the deciduous and permanent tooth segments of the dentition.

Adolescent↗

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↗