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Biomedical subjects

J Lindhe

Publications and source records attributed to J Lindhe.

At least 19 recordsLinked to original sources
PubMed1992

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↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1992

Probing pocket depth at mobile/nonmobile teeth.

The aim of the present investigation was to study the influence of an increased tooth mobility on the resistance offered by the periodontal tissues to probing. 6 beagle dogs were used. At the start of the experiment, the animals had clean teeth and normal gingival and periodontal conditions. In each dog, a device was installed in the lower left jaw quadrant to expose the third premolar (P3) to jiggling forces which would enhance the mobility of this "test" tooth. The contralateral tooth served as the non-jiggled control. During the 3 months of experimentation, the teeth of the dogs were cleaned on a regular basis. Clinical examinations including tooth mobility measurements were performed on days 0 and 90. After the examination on Day 90, a probe was inserted in the buccal "pocket" of the mesial root of 3P and P3. The probe was retained with composite. Biopsies including the test or control tooth with adjacent buccal periodontal tissues were harvested, fixed and decalcified. Each biopsy was divided in one mesial and one distal portion (root). The distal portion was embedded in Epon, sectioned and stained in PAS and toluidine blue, while the mesial portion, following probe removal was embedded in paraffin, sectioned and stained in hematoxylin-eosin. The sections were exposed to histometric and morphometric measurements. The findings demonstrated that tissue alterations which occur at mobile teeth may reduce the resistance offered by the periodontal tissues to clinical probing. Such alterations include (i) reduced height of the alveolar bone, (ii) reduced amount of collagen, and increased vascularity in the enlarged supracrestal connective tissue.

Animals↗
PubMed1992

The effect of supragingival plaque control on the subgingival microbiota in subjects with periodontal disease.

The present investigation was performed to study the effect on the subgingival microbiota, of a plaque control program which included meticulous oral hygiene instruction, supragingival scaling and professional monitoring during a 2 year period. 300 subjects were examined for periodontal disease and monitored for 2 years without treatment. After the 2 year examination, 80 subjects were invited to participate in a treatment program intended to improve the standard of their self-performed plaque control. 40 of the invitees had a gingivitis and only minor attachment loss, while 40 subjects had moderate signs of periodontitis. 62 subjects volunteered for this treatment. 23 of the volunteers (Group AB) had several sites with deep pockets (> 4 mm). 39 of the volunteers had gingivitis but shallow pockets only (Group C). Group AB contributed 31 shallow pocket sites (A-sites) and 40 deep pocket sites (B-sites), while Group C contributed 63 shallow sites (C-sites). After the clinical examination, samples of the subgingival microbiota were harvested from the 134 A, B and C sites. The 62 subjects were enrolled in a supervised oral hygiene program. Supragingival scaling was carried out. Oral hygiene instruction was provided and repeated on an individual need basis so that all subjects reached and maintained a supragingival plaque score which was < 20%. 24 months after the year 2 examination, the 62 subjects were examined again using both clinical and microbiological examination procedures. The findings demonstrated that carefully performed supragingival plaque control changed the quantity and the composition of the supragingival microbiota.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Clinical and structural characteristics of periodontal tissues in young and old dogs.

The aim of this study was to examine some clinical and structural features of healthy periodontal tissues in young and old beagle dogs. The material consisted of 10 beagle dogs; group I (1-year old) and group II (8-9 years of age). All animals belonged to the same beagle dog colony and had been carefully monitored from birth. A given day was termed day 0 on which the teeth of all 10 dogs were scaled and polished and a 6-week period of enhanced plaque control was initiated. On day 42, clinical examinations were performed and biopsies obtained from the right mandibular 4th (4P) and 3rd (3P) premolar regions. The biopsies were prepared for histometric and morphometric analyses. Clinically, the lower premolars of the old but not the young dogs showed signs of marked wear. In the old dogs, the free gingival unit had a more curved and bulky appearance than in the young animals and in the old dogs, the free gingiva was consistently separated from the attached gingiva by a gingival groove. The histometrical dimensions of the free marginal gingiva and the width of the coronal portion of the periodontal ligament did not differ between the 2 groups of dogs. The apical cells of the junctional epithelium (aJE) in the young dogs were consistently located at the cemento-enamel junction (CEJ), whereas in the old dogs, aJE was consistently located apical to the CEJ.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1991

The effect of an anticalculus dentifrice on calculus formation and gingival recession in Thai children and teenagers: one-year study. Study #1. An anticalculus dentifrice containing 3.3% soluble pyrophosphate and 1.0% of a copolymer.

A one-year, double-blind clinical study was conducted on a population of Thai children and teenagers to determine the effect of the twice daily use of an anticalculus dentifrice on supragingival calculus formation and gingival recession, as compared to the use of a placebo dentifrice and the continuation of customary oral hygiene procedures. The subjects were initially evaluated for calculus using the Volpe-Manhold procedure and for gingival recession using the GRT procedure of Volpe, Triratana, and Rustogi. All subjects received an oral prophylaxis and were assigned to the use of 1) a placebo dentifrice containing 0.243% sodium fluoride in a silica base, 2) an anticalculus dentifrice containing 3.3% soluble pyrophosphate and 1.0% Gantrez copolymer--in a 0.243% sodium fluoride/silica base, or 3) continuation of customary oral hygiene procedures. After one year, the subjects using the anticalculus dentifrice had 37.01% less supragingival calculus and 25.09% less gingival recession than the subjects using the placebo dentifrice. Additionally, after one year, the subjects using the anticalculus dentifrice had 34.86% less supragingival calculus and 29.95% less gingival recession than the subjects who continued their customary oral hygiene procedures. All reductions were statistically significant at the 95% or greater level of confidence.

Adolescent↗
PubMed1979

The effect of metronidazole on the development of plaque and gingivitis in the beagle dog.

The present investigation was performed in order to assess if the administration of metronidazole changed the composition of developing plaque in dogs, which at the start of the study were free from signs of gingivitis. Five beagle dogs were used. Throughout the observation period the animals were fed a diet which favored plaque accumulation. A baseline examination involved assessments of plaque, gingivitis and gingival exudate. Gingival biopsies were sampled and the tissue examined by a point counting procedure. The composition of the subgingival bacterial flora was assessed by dark-field microscopy. The bacteria were characterized into the following types: coccoid cells, straight rods, filaments, fusiforms, motile and curved rods and spirochetes. Following the baseline examination the teeth of the right jaws were allowed to accumulate plaque. A careful tooth cleaning program was maintained in the left jaw quadrants. Plaque and gingivitis assessments were repeated and biopsies sampled in the right jaws after 7, 14 and 28 days of no tooth cleaning. On experimental day 28 the second part of the study was initiated. A baseline examination was performed in the left jaws, after which the tooth cleaning program also in this part of the dentition was terminated. During the subsequent 28-day period each animal was given a dosage of 20 mg metronidazole/kilogram bodyweight/day. Clinical examinations and biopsies were repeated after 7, 14 and 28 days. The results demonstrated that metronidazole administered via the systemic route during a 28-day period can effectively decrease plaque and gingivitis development in dogs. The bacterial flora from subgingival sites of healthy gingiva was dominated by coccoid cells and straight rods. During the phase of developing gingivitis the percentage of coccoid cells and rods tended to decrease, while motile rods and spirochetes increased. During the 28 days of metronidazole treatment the subgingival plaque flora maintained its "healthy" composition, i.e. a gradual influx of motile rods and spirochetes was prevented.

Animals↗
PubMed1979

The effect of tetracycline and/or scaling on human periodontal disease.

The objective of this study was to test the efficacy of scaling and root planing with or without adjunctive tetracycline therapy in the treatment of periodonitis in humans. The presence of plaque, gingival inflammation, probing depths and attachment levels was assessed for all teeth in 12 patients with chronic, advanced periodontitis. After an initial examination all patients were given detailed oral hygiene instructions. The teeth in one-half of each arch were then scaled and root planed. The teeth in the contralateral half were not treated. Six patients were given tetracycline (1 gm/day) during the first and second weeks and the seventh and eighth weeks of the trial. The study thus included four different treatment groups: 1) no treatment, 2) scaling and root planing alone, 3) tetracycline administration alone, and 4) scaling and root planing combined with tetracycline administration. All patients were reexamined at 8 and 25 weeks subsequent to the initiation of therapy. Both PlI and GI scores decreased significantly in all groups. The GI scores were significantly lower in the scaled and root planed areas as compared to the contralateral sides at both the 8- and 25-week examinations. The PlI score was lower in the scaled and root planed areas only at the 25-week interval. The gingival probing depths were reduced in all groups. A significantly greater decrease in probing depth, however, was noted in scaled and root planed areas. There was a trend to gain of attachment in the treated areas but the magnitude of the gain was very small. The findings of the trail also revealed that the administration of tetracycline had only a minor effect on the parameters examined.

Adult↗
PubMed1979

Effect of hydrogen peroxide on developing plaque and gingivitis in man.

The present experiment was undertaken to assess the effect of hydrogen peroxide release during mouth rinsings on the composition of the microbiota of developing plaque in humans and the amount and pathogenecity of the plaque formed. The trial was designed as a double-blind crossover study of the effect of a mouthwash (Amosan) had a placebo rinse on the development of plaque and gingivitis in young adults. The active compound was available as a powder; the rinse consisted of 1.7 g powder dissolved in 30 ml hot tap water. Fourteen dental students participated in the trial. The students were examined during two consecutive periods, each consisting of one preparatory (during which active tooth cleaning measures were carefully practiced) and one main test period (during which mouth rinsings were the only plaque control measure). Each of the two test periods was initiated by a baseline examination following which the participants rinsed either with the active or the placebo mouthwash. The rinsings were performed immediately after breakfast, after lunch and after dinner. Measurements of Plaque and Gingival Index scores were performed 4, 7 and 14 days after the start of the no-toothbrushing period. Bacteria were sampled and examined after 7 and 14 days of trial. The results demonstrated that a mouthwash which released hydrogen peroxide effectively prevented the colonization of filaments, fusiforms, motile and curved rods as well as spirochetes in developing plaque. The mouthwash which was used as the only oral hygiene measure during a 2-week period furthermore markedly reduced the amount of plaque formed and significantly retarded gingivitis development. It is suggested that H202 released by mouthwashes during rinsing may prevent or retard the colonization and multiplication of anaerobic bacteria.

Clinical Trials as Topic↗