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Biomedical subjects

J Lindhe

Publications and source records attributed to J Lindhe.

At least 109 records · Page 6Linked to original sources

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↗

Epithelial remnants in the crestal periodontium of the dog.

The purpose of this study was to access the effect of age on the epithelial remnants (EPRs) of the crestal periodontal tissues of beagle dogs. The material consisted of 10 beagle dogs; 5 were 1-year-old (young dogs) and 5 were 9-years-old (old dogs). All animals belonged to the same dog colony and had been raised under similar conditions. Since birth, the dogs had been subjected to professional prophylaxis 4x /per year. Biopsies were obtained from the mandibular 3rd and 4th premolar regions and were prepared for histologic analysis. 2 areas, (1) the supracrestal region and (2) the marginal periodontal ligament region, were identified. The supracrestal region was further divided into 4 compartments of equal height. The histologic parameters studied included: the (i) number of EPRs/mm root length; EPR frequency; (ii) size of EPR; (iii) distance between the root surface and the EPR; (iv) distance between the alveolar bone and the EPR; (v) epithelial cell area. The supracrestal region (total and various compartments) of old dogs harbored significantly fewer yet larger EPRs than epithelial remnants of young dogs. Similarly, the EPR's of the periodontal ligament region were significantly larger and closer to the root surface in old dogs compared to young dogs. No difference was noted in the cell area of EPRs between young and old dogs for either region. Epithelial remnants of the supracrestal region in both groups of dogs were somewhat more frequent, larger and positioned further from the root surface than the EPRs of the periodontal ligament region.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

Gingivitis in young and old dogs.

The aim of the investigation was to study the development of gingivitis in young and old dogs. 10 beagle dogs were used. 5 of the dogs were 1 year old and 5 dogs were between 8 and 9 years of age. On day 0, all the teeth of all 10 dogs were scaled and polished. A 6-week period of plaque control was initiated. On day 42, a clinical examination was performed, microbial samples from the gingival sulcus were harvested and biopsies obtained from tooth regions 3P and 4P. The tooth-cleaning measures were abandoned following biopsy and the animals were during the subsequent 3 weeks allowed to form plaque. On day 63, i.e., day 21 of plaque formation, the clinical examination, sampling of the subgingival plaque and harvesting of biopsies were repeated in the contralateral premolar regions (P3 and P4). The histological analysis revealed that the cellular infiltrate (the lesion) of inflamed gingiva was larger and extended more apically in the old than in the young dogs. The lesion in the old dogs contained significantly more plasma cells but less macrophages, lymphocytes and PMN cells than the infiltrate in the young dogs.

Aggregatibacter actinomycetemcomitans↗

The effect of a triclosan-containing dentifrice on established plaque and gingivitis.

The aim of the present clinical trial was to study the effect on existing plaque and gingivitis of an oral hygiene regimen which utilized a dentifrice which contained triclosan. 120 subjects were recruited for the trial. They were examined for plaque and gingivitis using the criteria of (i) the Turesky modification of the Quigley & Hein plaque index and (ii) the Löe & Silness gingival index. Plaque and gingivitis were assessed in all parts of the dentition and at 6 location points around each tooth. Following a baseline examination, the subjects were stratified in 2 balanced groups based on age, plaque and gingivitis scores. The subjects were randomly assigned to the following treatment: 1 test group used a dentifrice containing triclosan/copolymer/fluoride and 1 control group used a traditional fluoride containing dentifrice. The participants were given the assigned dentifrice and a soft-bristled toothbrush for home use. They were instructed to brush their teeth in the morning and in the evening for one minute each time. They were reexamined 6 weeks, 3 and 6 months after the baseline examination. The findings from the re-examinations revealed that an oral hygiene regimen which utilized a dentifrice which contained triclosan/copolymer significantly reduced pre-existing plaque and gingivitis above what was accomplished by a traditional fluoride containing dentifrice. The improvement of the gingival conditions occurred in all parts of the dentition and at all tooth surfaces and units. In addition, the present data support the hypothesis that triclosan may induce alterations in the quality of existing plaque.

Adult↗

The effect of subgingival debridement on periodontal disease parameters and the subgingival microbiota.

The aim of the present investigation was to analyse the effect of subgingival scaling and root planing in subjects who prior to treatment exercised meticulous supragingival plaque control. 300 subjects were examined at baseline and after 1 and 2 years without treatment. After the year 2 examination, 62 subjects were randomly selected for therapy. They were given detailed instruction in proper self-performed toothcleaning measures and were carefully monitored during the subsequent 2 years. Following the year-4 examination, 2 quadrants, 1 maxillary and 1 mandibular in each subject, were randomly selected for additional therapy. The teeth in the selected quadrants were exposed to subgingival scaling and root planing. The subgingival therapy was repeated until a site no longer bled on gentle probing. This basic therapy was completed within a 2-month period. All subjects were re-examined after another 12-month interval. The examinations at year 4 and 5 included assessment of plaque, gingivitis, probing pocket depth and analysis of samples obtained from the subgingival microbiota at 134 selected sites. The findings from the present study demonstrated: (i) that subgingival scaling and root planing were effective in eliminating subgingival plaque and gingivitis; (ii) that professional therapy resulted in a pronounced reduction of probing depth at sites which at year 4 had a probing depth > 3 mm; (iii) that in non-scaled quadrants, the extension of self-performed plaque control resulted in a continued improvement of the periodontal conditions at sites which at year 4 were < 5 mm deep.

Adult↗

Progression of periodontal tissue destruction at splinted/non-splinted teeth. An experimental study in the dog.

The aim of the present investigation was to study whether splinting, i.e., immobilisation of teeth, may interfere with the rate of periodontal tissue destruction that can be accomplished by ligature placement and plaque accumulation, 5, 1-year-old, beagle dogs were included in the experiment. The mandibular 2nd and 3rd premolars and the 1st molar on both sides of the mandible were extracted. 2 titanium implants were installed in the sites of 3P and 1M, i.e., in the right quadrant of the mandible. 3 months later, abutment connection was performed and a fixed, gold splint, connecting the tooth and the implants, was inserted. The non-resilient splint was cemented in place on Day 0 and 4P was hereby immobilized. In each dog, the contralateral fourth premolar (P4) served as the non-splinted control tooth. Experimental periodontal tissue breakdown was initiated by placing cotton floss ligatures around the neck of 4P and P4 and by allowing the animals to accumulate plaque and calculus. Once every month, new ligatures were placed at the level of the receding gingival margin. The experiment was terminated on Day 180. Radiographs of 4P and P4 were obtained and biopsies sampled. The results of the measurements, made in the radiographs and the histological sections, disclosed that the splinting of the experimental teeth, failed to prevent or retard apical downgrowth of plaque and associated attachment loss. It was concluded that increased tooth mobility, within the limits of the present experiment, obviously did not establish conditions which favoured an enhanced destruction of the periodontal tissues in the beagle dog model.

Alveolar Bone Loss↗

Periodontal conditions of adult regular dental care attendants. A 12-year longitudinal study.

The purpose of the present study was to examine longitudinal alterations in the periodontal conditions of regular dental care attendants. 225 randomly selected patients (age 18-65 years) at 12 community dental clinics in the county of Värmland, Sweden, were subjected to a baseline clinical and radiographic examination in 1978 and to a re-examination in 1990. During the study period, all participants received preventive and therapeutic measures according to decisions made by the dentist on duty in the clinics. The examinations involved assessments of number of remaining teeth, plaque, gingivitis, probing pocket depth, loss of probing attachment and periodontal bone height. The results showed that during the 12 years of monitoring, an average of 0.4 teeth were lost. The % of tooth sites with gingivitis was lower in 1990 (4%) than in 1978 (15%), but no major changes were found for the mean probing pocket depth. The mean probing attachment loss during the 12 years amounted to 0.5 mm. The tooth site analysis revealed that buccal sites had experienced more loss of attachment than lingual and approximal surfaces. Whereas no differences were observed between age groups with respect to longitudinal loss of attachment at lingual and approximal tooth sites, the youngest age group demonstrated more pronounced loss at buccal surfaces than older subjects. The radiographic assessments of the alveolar bone height revealed a mean longitudinal loss amounting to 0.2-0.4 mm in the various age groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Probing depth at implants and teeth. An experimental study in the dog.

The aim of the present investigation was to assess the resistance offered by the gingiva at teeth and the peri-implant mucosa at osseointegrated titanium implants to mechanical probing. 5 beagle dogs were used in the experiment. The 2nd and 3rd premolars and the 1st molars of the right and left mandibular dentition were extracted. 2 titanium implants were installed in the edentulous right and left premolar- and molar-regions. Abutment connection was performed 3 months later. The remaining premolar in the left jaw (P4) was exposed to "experimental periodontitis" during a 4-month period and, thus, the 4th premolar in the right jaw (4P) was representing healthy periodontium. The inflamed soft tissues at P4 were treated using a flap procedure. Following 2 weeks of healing, the main experiment was started, i.e., day 0. During the subsequent 360 days, the teeth and abutment parts of the implants were regularly exposed to plaque control (3 x/week). Radiographs of 4P-, P4- and the implant-regions were obtained on days 0 and 360. Mobility measurements were performed on days 0 and 360. Biopsies of the experimental teeth and the implants were sampled at the end of the study. The results of the present experiment demonstrated that differences in terms of tissue composition, organization and attachment between the gingiva and the root surface on one hand and between the peri-implant mucosa and the implant surface on the other, make the conditions for probing depth measurements at teeth and implants different.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Process↗

Comparative estimation of periodontal conditions by means of different index systems.

The aim of the present study was to compare epidemiological data of periodontal disease obtained from a sample of adults by means of different, commonly employed, partial and full-mouth index systems, in order to explore the amount of discrepancy attributed to the methodology per se. 169 dentate subjects, aged 25-64 years, were subjected to a clinical examination, including circumferential probing assessments of pocket depth (PPD) and attachment level (PAL) at all teeth present. The individual mean % of tooth sites with PPD of > or = 6 mm and the % of subjects exhibiting at least one such deep pocket were calculated based on (i) full-mouth data, (ii) data derived from the buccal and mesial surfaces from 1 randomly selected upper and 1 lower quadrant, (iii) probing assessments at the 6 "Ramfjord teeth", (iv) the full-mouth community periodontal index for treatment needs (CPITN), and (v) the partial CPITN based on 10 index teeth. The PAL data were analyzed by means of 3 versions of the extent and severity index, 1 generated by full-mouth assessments and 2 by partial assessments based on 28 and 10 tooth sites, respectively. In the entire sample, the individual mean % of sites with PPD of > or = 6 mm generated by the different systems ranged between 5.0 and 4.2 sites/subject. By full-mouth CPITN scorings, an average of 1.0 score-4 sextants/subject was recorded, while the partial CPITN generated a corresponding value of 0.8 score-4 sextants/subject.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

On the relationship between crown form and clinical features of the gingiva in adolescents.

The purpose of the present study was to examine the relationship between the form of the crowns in the maxillary front tooth segment and (1) a group of morphological characteristics and (2) the thickness of the gingiva. 108 subjects devoid of symptoms of destructive periodontal disease were examined regarding, e.g., probing depth, thickness of the free gingiva, width of the keratinized gingiva and the contour of the marginal gingiva. From clinical photographs of the maxillary front tooth region, the width (at the apical third--CW) and the length (CL) of the crowns of the 6 front teeth were determined. A CW/CL-ratio was calculated for each tooth and averaged for each tooth region. The individual mean CW/CL-ratio values for the central incisors were ranked. After correction for incisal attrition, the 10 subjects ranked highest and the 10 ranked lowest were selected as having either a long-narrow (group N) or a short-wide (group W) form of the crown of the tooth. The data for each of the examined parameters were averaged for each tooth region in each subject and mean values for subjects in groups W and N were compared using the Student t-test. Stepwise multiple regression analysis, including data from the whole sample, was performed for each tooth region with the thickness of the free gingiva as the dependent variable.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Soft tissue reaction to de novo plaque formation on implants and teeth. An experimental study in the dog.

The aim of the present investigation was to assess the effect of de novo plaque formation on the gingiva and masticatory mucosa around teeth and implants. The study was performed in 5 beagle dogs which at the initiation of the experiment were 15 months old. During a preparatory period, the mandibular right premolars were extracted, 3 fixtures installed, abutment connection performed and a 4-month period of plaque control completed. A clinical examination was performed and biopsies of the second mandibular premolar (P2) and the contralateral implant site (2P) were sampled. The dogs were allowed to form plaque during a period of 3 weeks. The clinical examination was repeated and biopsies harvested from the 2 remaining implants and the contralateral tooth sites. The tissue samples were prepared for histometric and morphometric analysis. Both the masticatory mucosa at implants and the gingiva responded to de novo plaque formation with the development of an inflammatory lesion. The size as well as the composition of the lesions in the 2 tissues had many features in common. It was concluded that the mucosa around implants and the gingiva around teeth had a similar potential to respond to early plaque formation.

Animals↗

Experimental breakdown of peri-implant and periodontal tissues. A study in the beagle dog.

The objective of the present experiment was to study lesions in the peri-implant and periodontal tissues resulting from ligature placement and subgingival plaque formation. The experiment was performed in 5 beagle dogs which at the start of the study were about 15 months old. They were given a diet which allowed gross plaque formation. The mandibular right premolars were extracted, 3 fixtures (a.m. Brånemark) installed and abutment connection performed. Towards the end of a 6-month plaque control period, a clinical and radiographic examination was performed. Ligatures were placed in a subgingival position at 2 of the implants and the contralateral premolars. Plaque was allowed to accumulate. After 6 weeks, the ligatures were removed. 1 month later, the clinical and radiographical examination was repeated and samples from the subgingival microbiota obtained. Biopsies from the teeth and implant sites were harvested and processed for histometric and morphometric analyses. The results from the clinical and histological examinations revealed that: (i) clinical and radiographic signs of tissue destruction were more pronounced at implants than at teeth; (ii) the size of the soft tissue lesion was larger at implants than at teeth; (iii) the lesion at implants but not at teeth extended into the bone marrow.

Alveolar Bone Loss↗

Long-standing plaque and gingivitis at implants and teeth in the dog.

The experiment was performed to evaluate the effects of long-standing plaque on the gingiva and peri-implant mucosa. 5 beagle dogs were used in the study. The mandibular right premolars were extracted. 3 months later, 3 titanium fixtures were installed and after another 3 months, abutment connection was performed. Plaque control, in the implant as well as the contralateral tooth regions, was maintained during a 4-month period prior to the start of the main experiment. On Day 0, the teeth and implant sections were examined with respect to plaque and gingivitis. The plaque control program was terminated. The animals were subsequently fed a diet which allowed gross plaque accumulation. After 90 days of undisturbed plaque formation, the dogs were re-examined and biopsies harvested from implants and contralateral teeth. On day 90, all teeth and implants had accumulated large amounts of plaque. The soft tissue at implants and teeth bled on gentle probing. The histological examination of the gingiva and the peri-implant mucosa revealed: (i) both tissues contained an inflammatory cell infiltrate; ICT, (ii) the apical extension of ICT was more pronounced in the peri-implant mucosa than in the gingiva and (iii) the composition of the 2 lesions had many features in common.

Animals↗

Enhanced gingivitis in the deciduous and permanent dentition. An experimental study in the dog.

The aim of the experiment was to analyze the reaction of the marginal gingival tissues to 21 days of plaque formation on buccal tooth surfaces in the deciduous and permanent dentition of beagle dogs. In order to enhance the formation of plaque, the buccal surfaces of the experimental teeth were coated with a composite filling material. 5 beagle dogs were used. The animals were monitored during 2 periods, called period A (42 days during the deciduous dentition) and period B (42 days during the permanent dentition). The dogs were 10 weeks old at the initiation of period A. Following 3 weeks of plaque control, a groove was prepared into the enamel of the buccal surfaces of the mandibular right 3rd (03P) and 2nd (02P) premolars. A cotton ligature was subsequently attached to the groove using an enamel/etch-technique and a composite filling material. The groove and the ligature did not interfere with the gingival margin but the composite material extended into the subgingival niche. The plaque control measures were abandoned. The animals formed plaque during the following 21 days. A clinical examination was performed and subgingival bacteria sampled on day 21. Moreover, biopsies were harvested from the 03P and 02P tooth regions. The biopsies were prepared for histometric and morphometric analyses. A 2nd plaque control regimen was initiated. Period B started when the dogs were 15 months old. Following 3 weeks of enhanced plaque control, a cotton ligature was attached as described above at the buccal surfaces of the mandibular left 3rd (P3) and 4th (P4) premolars.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Guided tissue regeneration in surgically-produced furcation defects. An experimental study in the beagle dog.

The aim of the investigation was to evaluate the potential for new attachment formation at various degree III furcation involvements in the beagle dog. 3 differently shaped furcation defects were prepared; one small and one large key-hole defect, and one furcation defect which was part of "circumferential" loss of attachment and bone. 15 beagle dogs were used in the experiments. The furcation defects were surgically created at mandibular premolars in the right and left side of the jaw. Test teeth were subsequently treated according to the GTR principle, while control teeth were treated without the application of membranes. The result from the histological examination of biopsy specimens revealed that GTR treatment may result in complete new attachment at surgically produced "through and through" furcation involvements in dogs. The study, however, also revealed that the size of the furcation defect as well as the shape of the surrounding alveolar bone were factors that determined the outcome of this kind of treatment. The treatment failures were consistently associated with flap recession during healing which resulted in the exposure of the furcation defect.

Alveolar Bone Loss↗

Patterns of de novo plaque formation in the human dentition.

The objective of the present clinical trial was to carefully assess the pattern of de novo plaque formation in the human dentition. 10 subjects aged 24-29 years were recruited for the study. None of the participants showed signs of destructive periodontitis. At the start of the preparatory period, they were given a thorough dental prophylaxis and oral hygiene instruction. For the next 2 weeks, the participants were carefully monitored and 1 x every 2 days examined with respect to plaque and gingivitis. At the re-examinations, they were also given professional tooth cleaning and instruction in proper plaque control measures. Towards the end of this 2-week period, the Day 0 examination was performed which revealed that the gingival tissues of all participants were in excellent clinical health. Following the Day 0 examination, all 10 subjects were exposed to professional tooth cleaning. During the next 14 days, they abolished all mechanical tooth cleaning efforts but were examined with respect to plaque on Days 1, 4, 7 and 14. The amount of plaque formed was examined using the criteria of the Plaque Index system (PlI). Each of 6 surfaces of each tooth in the dentition was given a score from 0 to 3. The results from the re-examinations demonstrated that in humans with clean teeth and normal gingiva, the abolishment of mechanical tooth cleaning rapidly resulted in de novo plaque formation. Most plaque, as assessed by the plaque index system, formed during the first 4 days of no tooth cleaning after which moderate additional amounts of plaque formed. It was observed that the mean PlI values for individuals, for groups of teeth and tooth surfaces, provide a proper overall estimation of plaque build up. The dynamics of plaque formation between examinations and in different parts of the dentition were more easily disclosed by the data describing % distributions of different score categories and the transition between scores from one examination to the next. The total amount of plaque formed on various tooth surfaces was best presented by so called "plaque pattern displays". The results also revealed that (i) the mandibular dentition harbored more plaque than the maxillary dentition, (ii) there was a difference in the mean PlI scores between the molar and the anterior tooth regions in the maxilla, but in the mandible such a difference could not be observed (except on Day 1), (iii) plaque accumulated most at the approximal surfaces and least at the palatal surfaces, and that (iv) differences in PlI scores between groups of teeth and tooth surfaces observed on Day 4 persisted through the Day 14 examination.

Adult↗

Preservation of probing attachment and alveolar bone levels in 2 random population samples.

The present study is an attempt to elucidate the relation between ageing and loss of periodontal tissue support, by studying the occurrence of probing attachment and alveolar bone loss in two samples of randomly selected individuals. The 1st sample was recruited in Japan and comprised 319 subjects aged 20-79 years. The 2nd sample was recruited in Sweden and comprised 192 subjects aged 30-65 years. All individuals underwent a radiographic and a comprehensive clinical examination, including recordings of probing attachment level. Within the 2 samples, subsamples of individuals whose periodontal status indicated minimal experience of destructive periodontal disease were selected. In these particular subsamples, it was revealed that a substantial proportion of tooth surfaces, also in older subjects, remained with no attachment or alveolar bone loss. To a lesser extent, this could be also observed when the entire samples were analyzed, despite the presence of abundant plaque and gingival inflammation. The results indicated that intact supporting periodontal tissues can be retained in subjects of increased age and corroborate the suggestion that loss of clinical attachment and alveolar bone is not an obligatory consequence of ageing.

Adult↗

A model for studying the effects of mouthrinses on de novo plaque formation.

The aim of the present study was to describe a 4-day no oral hygiene model to assess the pattern of de novo plaque formation and to use this model to appraise the potential of some mouthwash preparations to retard or inhibit plaque formation in the human dentition. 10 subjects were recruited for the trial. During a preparatory period, the participants were exposed to repeated professional plaque control and given oral hygiene instruction to eliminate signs of gingivitis. At the end of the preparatory period, each participant received a final professional tooth cleaning and was subsequently told to abstain from mechanical plaque control efforts for the next 4 days. They were asked to rinse twice daily for 60 s with 10 ml varying test solutions. On Day 4, the volunteers were exposed to a new clinical examination and the presence and amount of plaque were examined by the use of the plaque index system (P1I). The participants were subsequently given a professional tooth cleaning and asked to exercise proper self performed plaque control during the next 10 days. A new test period was then initiated. 6 different mouthwash preparations were tested in each subject namely, (1) placebo (a negative control rinse), (2) Veadent mouthrinse, (3) Listerine mouthrinse, (4) 0.06% triclosan + polyvinyl phosphonic acid (PVPA), (5) 0.06% triclosan + phenolic flavor and (6) 0.12% chlorhexidine digluconate (a positive control rinse). The results from the study revealed that the mean P1I values for individuals, groups of teeth and tooth surfaces provide an adequate but gross overall estimation of the potential of a given mouthrinse to retard/inhibit plaque build up. More detailed information on the effects of the test rinses could be obtained by data describing the % distribution of different P1I score categories; a high frequency of score 0 describes the potential of a mouthrinse to maintain tooth surfaces free from plaque while a low frequency of score 2/3 describes the ability of a treatment to retard/prevent gross plaque formation. The plaque pattern displays finally allowed assessment of the magnitude of plaque prevention, in comparison to the positive and negative controls, that could be achieved by a given compound in various parts and surfaces of the dentition. In this model, all test rinses (i) were significantly more effective than the placebo rinse in retarding de novo plaque build up and (ii) had a minor effects on plaque build up in the maxillary molars and at the approximal surfaces.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗