bluuebunny/crossref_metadata_2025 huggingface dataset:
Bone regeneration in orthodontically produced alveolar bone dehiscences
Authors: Karring Thorkild , Nyman Sture , Thilander Birgit , Magnusson Ingvar
Published: July 2006

Orthodontic appliances, designed to tip the maxillary second and third incisors in facial direction, were inserted in 3 dogs. During a 5 month period, the incisors on the left side of the jaw were tipped to a facially displaced position. During a further 5 month period these teeth were moved back to their original position while the two incisors on the right side of the jaw were moved to a position corresponding to that previously reached by the incisors of the left side. The orthodontic appliances were then used to retain the teeth In these positions for 5 months. Teeth in three non‐treated dogs served as controls. During the study, the animals were subjected to meticulous plaque control. The animals were sacrificed 15 months after the start of the study. The jaws were removed and buccolingually oriented histological sections of the experimental and control teeth were produced. The study has shown (1) that dehiscences can be produced in the alveolar bone by tipping teeth in facial direction and that bone will reform in such defects when the teeth are moved back to their original position and (2) that such tooth movements are not necessarily accompanied by loss of connective tissue attachment.
Bone regeneration in alveolar bone dehiscences produced by jiggling forces
Authors: Nyman Sture , Karring Thorkild , Bergenholtz Gunnar
Published: July 2006

The aim of this experiment was to achieve support for the hypothesis that bone resorption, induced by jiggling forces, leaves a component within the supracrestal soft tissue with a capacity of reforming bone. The maxillary lateral incisors and first premolars and the mandibular second premolars in two monkeys were used in the study. Using metal pins inserted into the neighboring teeth as retainers, orthodontic elastics were stretched and placed alternately around the buccal and lingual surfaces of each experimental tooth in order to produce jiggling forces. After 5 months of continuous jiggling, when bone dehiscences were produced on the buccal aspect of the teeth, the elastics were removed. After repositioning of the teeth a split thickness flap was raised. On one side of the jaw the soft tissue within the bone dehiscences was removed. At the contralateral teeth a sham operation was performed maintaining the soft tissue within the bone dehiscences. The monkeys were sacrificed 6 months after surgery. Tissue blocks containing test and control specimens were dissected free and prepared for microscopic analysis. The length of the supracrestal connective tissue attachment and the amount of coronal bone regeneration were assessed in the histological sections. It was found that buccal alveolar bone, reduced in height by jiggling forces, regenerated after discontinuation of the forces. When the soft tissue within the buccal bone dehiscences produced by the jiggling forces was surgically removed, the coronal regeneration of the alveolar bone was markedly reduced. These observations suggest that bone resorption, induced by jiggling forces, leaves a soft tissue component with a capacity of forming bone.
Lymphoproliferative response of submandibular nodes to mitogens in experimental gingivitis in dogs
Authors: Yoshie Hiromasa , Yamazaki Kazuhisa , Sawada Jun , Watanabe Tomiei , Hara Kohji
Published: July 2006

The purpose of the present study was to evaluate the lymphoproliferative response of submandibular nodes cells to stimulation by phytohemagglutinin (PHA), concanavalin A (Con A), and lipopolysaccharide (LPS) following experimental gingivitis in dogs.

In 4 dogs of the experimental group, gingival inflammation was induced by cervical ligatures on the left jaw, and the right jaw was kept clean by toothbrushing. In 2 dogs of the control group, toothbrushing was performed throughout. After the weight and lymphocyte number in the submandibular nodes were calculated, the lymphocyte response was determined by the uptake of 3H‐thymidine.

The weight and lymphocyte number of the ipsilateral nodes increased 2.2 and 3.7 times, respectively, as compared with the contralateral nodes. There was a higher background proliferation of unstimulated lymphocytes from ipsilateral nodes. The lymphocyte response to lower PHA concentration from ligated side lymphnodes significantly increased compared to that from contralateral nodes. It is suggested that the plaque accumulation and the intensive gingival inflammation considerably influence lymphocytes in the submandibular nodes.
Susceptibility to chlorhexidine of plaque streptococci after two years oral chlorhexidine hygiene
Authors: Mikkelsen Lena , Bbørglum Jensen S. , Löe Harald
Published: July 2006

The purpose of the present study was to examine if streptococci, isolated from human dental plaque in experimental subjects having practiced 2 years daily oral chlorhexidine hygiene, showed any difference in susceptibility to chlorhexidine compared to plaque streptococci isolated from a control group. The minimal inhibitory concentrations (MIC) of chlorhexidine were determined using the broth dilution test tube method. From an 18 h culture of each strain in brain heart infusion, 0.2 ml were inoculated into 5 ml brain heart infusion with added chlorhexidine to final concentrations of 0, 0.5, 1, 2, 4, 8, 16, 32, and 64 μg per ml. Three months later identical tests were performed. In both tests strains of Streptococcus mutans, Streptococcus milleri and Streptococcus salivarius were found to be the most susceptible to chlorhexidine, showing MIC around 4 μg chlorhexidine per ml. Strains resembling S. milleri appeared slightly less susceptible than strains identified as S. milleri. The majority of the S. sanguis strains had MIC ranging from 8 to 16 μg per ml. This species was slightly more susceptible than a group of streptococci intermediary to S. sanguis and S. mitior, while the susceptibility of the S. mitior strains ranged from 4 to more than 64 μg per ml. A difference in susceptibility to chlorhexidine between strains isolated from the chlorhexidine group and the control group was only observed for S. sanguis. Strains of this species isolated from the chlorhexidine group showed higher MIC than did strains isolated from the control group.
A longitudinal study into the depth of the clinical gingival sulcus of human canine teeth during and after eruption
Authors: Smith Roger G.
Published: July 2006

The depth of the healthy clinical gingival sulcus was investigated in 32 school children by measuring with a flexible rule the sulcus depth of 43 erupting permanent canine teeth. Crown height and the distance to occlusion were measured on casts. One third of the subjects were studied formore than a year, the longest period being 109 weeks. Initial measurements of sulcus depth, before any teeth had reached occlusion, were in the 4.0−13.0 mm range. Final measurements, 17 teeth then being in occlusion, were in the 1.5−6.5 mm range.

The sulcus depths of 57 adjacent occluding teeth remained in the 0.5−4.5 mm range.

For teeth having a crown height of up to 2 mm when first seen, measurements of sulcus depth and crown height were pooled about monthly intervals. Curves plotted from the means of these values showed a generally smooth increase in crown height and similar decrease in sulcus depth, maximal early in eruption, although no two teeth behaved identically.
The relationship between pontic hygiene and mucosai inflammation in fixed bridge recipients
Authors: Silness J. , Gustavsen F. , Mangersnes K.
Published: July 2006

Professional and personal hygiene measures were instituted in bridge recipients who demonstrated subpontic inflammatory lesions of the mucosa. The study group consisted of 16 participants (10 9♂ 6♀) with 27 pontics in all. Criteria of the Plaque and Gingival Index systems were used to describe the occurrence of plaque and mucosai inflammation. Occurrence of mineralized deposits was determined radiographically. Gram‐stained smear preparations were prepared for bacteriological examination. An estimate of the outgrowth of yeasts was obtained by a miniaturized culture test system. After hygiene periods of varying lengths of time, the clinical signs of inflammation disappeared. It is concluded that bacterial plaque is essential for the production of inflammation of the mucosa subjacent to bridge pontics.
Tetracycline treatment of periodontal disease in the beagle dog
Authors: Jeffcoat M. K. , Williams R. C. , Kaplan M. L. , Goldhaber P.
Published: July 2006

Bone‐seeking radio pharmaceutical uptake (BSRU) was used to examine alveolar bone metabolism in a longitudinal study of tetracyclinc efficacy ID beagle dogs. BSRU was measured in untreated control dogs and in beagles receiving either 250 mg or 500 mg oral tetracycline‐HCI daily for 16 months. The rate of boneless was determined from radiographs taken semiannual!)’for a 6‐month pretremment period and for a 24‐month treatment period. Measurements of BSRU obtained ai month 16 of treatment were correlated with rates of bone loss determined radiographically in an attempt to determine whether BSRU was indicative of the subsequent rate of boneless. A reduced rate of alveolar bone loss was found in the 500 mg tetracycline group at month 16 of the study relative to the untreated controls which was consistent with the decreased bone‐seeking radio pharmaceutical uptake observed in this group. A significantly increased BSRU (p < .0001) was found in the 250 mg tetracycline group at month 16 of study relative to the untreated and 500 mg tetracycline groups. A rapid increase in the rale of bone loss in the 250 mg tetracycline group which was not detectable prior to 16 months of treatment became evident radiographically by 24 months. Thus, increased BSRU in the 250 mg teiracyclinc group appeared to detect the loss of the effect of telracycline on reducing the rate of alveolar bone resorplion in these beagles several months prior to radiographic evidence of the loss of the effect of tetracycline (escape phenomenon).
Classification and identification of Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus by cluster analysis and deoxyribonucleic acid hybridizations
Authors: Tanner A. C. R. , Visconti R. A. , Socransky S. S. , Holt S. C.
Published: July 2006

Fifteen gram‐negative, saccharolytic rods isolated from advanced periodonlal pockeis were compared to type and reference strains of Arlinohacillus actinomycetemcomitans, Haemaphilus aphrophilus, and reference strains of Haemophilus paraphrophilus. Phenotypic features of organisms were used in cluster analysis and multidimensional scaling. Deoxyribonucleic acid (DNA) was extracted from all strains and moles percent guanine plus cytosine content determined. DNA/DNA homology experiments were performed between reference strains of each species and oral isolates. Five strains from periodontosis lesions, two strains from Papillon‐Lefevre periodontal lesions, and four strains from periodontitis pockeis of adults were similar to A. actinomycetemcomitans by cluster analyses and by DNA/DNA homologies. Except for a single H. paraphrophilus isolate, the H. aphrophilus and H, paraphrophilus isolates could not be distinguished as two distinct species as there was overlap in biochemical characteristics and DNA/DNA homology. Two strains isolated from periodontosis lesions, two strains from adult periodontilis sites, and three oral reference strains were very similar to each other and to the H. aphrtiphilus type strain using phenotypic features. Hydrogen peroxide decomposition was not found to be a consistent feature of A. actinomycetemcumitans strains isolated from periodontal pockets.
Neutrophil chemiluminescence in response to Fusobacterium nucleatum
Authors: Passo Samuel A. , Syed Salam A. , Silva Joseph
Published: July 2006

During the interaction of bacteria or other particles with neutrophils, oxygen consumption is increased, and unstable reduction products are produced. Chemiluminescence is the light energy produced in the neutrophil by the generation of unstable oxygen radicals. These oxygen radicals are thought to be important in the destruction of bacteria as well as host tissues. Therefore, we wanted to investigate the ability of Gram‐negative plaque bacteria to stimulate neutrophil chemiluminescencein vitro.

The major groups of bacteria examined wereFusobacterium, Bacteroides, Capnocytophaga. Selenomonas. and Trcponema. Of these bacteria,Fusobacterium nucleatumhad by far the greatest ability to stimulate neuirophil chemiluminescence in the absence of serum. Our results suggest that stimulation of neutrophil chemiluminescence byF. nucleatumis mediated by a protein moiety on the bacterial cell surface. This conclusion is supponed by experiments demonstrating significant inhibition of neuirophil chemiluminescence by heat, 2% formalin, or trypsin pre‐treatment ofF nucleatum. Also, neutrophil chemiluminescence was stimulated in a similar fashion with intactF. nucleatumonly by the cellassociation centrifugation pellet of sonicatedF. nucleatum. The monosaccharide D‐galactose. which is a component of erythrocyte glycoproteins andF. nucleatumlipopolysaccharide. caused significant inhibition of neutrophil chemiluminescence at 100 mM final concentration. The unusual and pronounced ability ofFusobacterium nucleatumto stimulate neuirophil chemituminescence in the absence of serum might be important in the pathogenicity and/or host defense in periodontal disease.
Specific progesterone receptors in rabbit gingiva
Authors: Vittek J. , Gordon G. G. , Rappaport S. C. , Munnangi P. R. , Southren A. L.
Published: July 2006

The cytoplasm and nucleus of male and female rabbit gingiva and cytoplasm of rabbit oral mucosa contain receptors capable of specifically binding progesterone and promegesiooe with high affinity (Kd =2.7 × 10−9 M) and low capacity (∼10 fmol/mg protein). The binding is sensitive to heat, is destroyed by warming to 37°C for 60 min by proteolylic enzymes (pronase and trypsin), and exhibits a pattern of competition similar to that obtained with progesterone receptors from other target tissues. These results provide evidence that rabbit gingiva and buccal mucosa may function as target tissues for progestms.
Inhibition of post‐extraction alveolar ridge resorption in rats by dichloromethane
Authors: Olson H. M. , Hagen A.
Published: July 2006

The therapeutic effect of dichloromethane diphosphonate (C12MDP) on postdental extraction alveolar bone resorption was studied in rats. Rais were injected with 10 mg Cl2MDP/kg/day s.c. for varying intervals from seven days prior to, through 27 days after extraction of maxillary molar teeth. Results demonstrated that C12MDP effectively inhibited rapid alveolar bone loss even after a brief interval of therapy (seven days of therapy prior to extraction), suggesting that the efficacy is not immediately reversible.
Demonstration and initial characterization of a latent collagenase secreted by human gingival fibroblasts
Authors: Wilhelm Scott M. , Javed Tariq , Miller Ronald L.
Published: July 2006

Cultured human gingival fibroblasts secrete a latent collagenase (EC 3.4.24.7). This latent collagenase can be activated proteolytically by trypsin and chemically by the organomercurials, p‐aminophenylmercuric acetate (APMA) or p‐chloromercuribenzoate (PCMB). Under optimal activation conditions, the latent collagenase was activated to the same extent by either trypsin or the organomercurial, APMA. The activated fibroblast collagenase hydrolyzed 14C‐collagen fibrils and cleaved Type I collagen in solution into three‐quarter and one‐quarter length cleavage fragments, which appeared identical to those produced by human gingival tissue collagenase obtained from organ culture. The fibroblast collagenase was inhibited by EDTA, 1,10–phenanthroline, cysteine, dithioerythritol, heparin, human serum, and α2‐macroglobulin but not by phenylmethylsulfonyl fluoride or N‐ethylmaleimide. The pH optimum for this neutral metalloproteinase was between 7.5 and 9.0. In addition, the secretion of this latent collagenase by cultured fibroblasts can be stimulated by the endocytosis of either mycostatin or latex particles.
Biological effects of a purified lipopolysaccharide from Bacteroides gingivalis
Authors: Nair B. C. , Mayberry W. R. , Dziak R. , Chen P. B. , Levine M. J. , Hausmann E.
Published: July 2006

Lipopolysaccharide (LPS) has been purified from Bacteroides gingivalis. The purity of this LPS is evidenced on ultracentrifugation, immunoelectrophoresis, and chemical analyses. On comparison with LPS from aerobic enteric organisms, LPS from Bacteroides gingivalis exhibits minimal potency when tested for pyrogenicity in rabbits and mitogenicity in mouse spleen cells. On the other hand, purified LPS from Bacteroides gingivalis exhibits high potency in its ability to stimulate 45Ca release from prelabeled fetal rat bones and to inhibit Ca influx into osteoclast‐like cells.
Lymphocytes from chronically inflamed human gingiva
Authors: Daly C. G. , Clancy R. L. , Cripps A. W.
Published: July 2006

Recovery and identification in vitro of lymphocytes from gingival tissue was carried out for 20 patients with chronic marginal gingivitis. A combination of 90 min incubation in a collagenase‐containing medium followed by mechanical disruption through a stainless‐steel grid resulted in a mean yield of 2.42 × 105 (S. D. ± 1.26 × 105: n = 16) lymphocytes per 100 mg or tissue. When Ficoll density centrifugation was introduced into the recovery procedure, the mean lymphocyte yield dropped to 2. 15 × 104 (S. D. ± 0.99 × 104: n = 4) per 100 mg. Mean viability of recovered lymphocytes was 78% (S. D. ± 5%: n =16) and for Ficoll separation, 77% (S. D. ± 1%: n = 4). In cell suspensions obtained from 12 or the patients, T lymphocytes were identified by rosette formation with sheep erythrocytes, and B cells were quantitated using fluorescent identification of membrane immunoglobulin. Macrophages were identified on the basis of non‐specific esterase characteristics. Tire predominant lymphocytes round were T cells, with a mean proportion of 53.9% (S. D. ± 5.6%); the mean proportion of B cells was 32.7% (S. D. ± 5.4%). Macrophages accounted for a mean of 7.7% (S. D. ± 2.8%) or the recovered lymphoid cells. The lymphocyte‐plasma cell ratio in recovered cell suspensions was 7:1 compared with a ratio of 1.7:1 noted in histological sections.
Secretion of a bone resorbing factor by epithelial cells cultured from porcine rests of Malassez
Authors: Birek C. , Heersche J. N. M. , Jez D. , Brunette D. M.
Published: July 2006

In the present study we have investigated the effect of factors released by cells derived from porcine epithelial rests of Malassez (ERM) on bone resorption in vitro. The osteolytic effect of these cells was tested by co‐culturing them with fetal rat calvariae and then measuring the cumulative change in calcium concentration of the culture medium. When ERM cells were cultured with calvariae for 4 days, there was a significant increase in calcium release from the bones compared with bones cultured without ERM. ERM cells alone did not change the calcium concentration of the culture medium. When calvariae there cultured in medium that had been collected from ERM cultures, significant bone resorption could also be obtained. Indomethacin (200 ng/ml), an inhibitor of prostaglandin synthesis, inhibited calcium release from control calvariae and from calvariae cultured with ERM. However, calvariae cultured in the presence of ERM and indomethacin released significantly more calcium than those cultured in the presence of indomethacin alone. Thus, factors other than PG account for the osteolytic effect of ERM. Other cells cultured from oral tissues, such as gingival fibroblasts and fibroblasts from periodontal ligament as well as rat osteosarcoma cells also stimulated calcium release from calvariae. These results show that many cell types have the capacity to release bone resorbing factors in vitro and support the belief that under suitable conditions in vivo breakdown of alveolar bone may be stimulated by tissues proximal to it.
Fluoride intake and alveolar bone loss in periodontal disease‐susceptible mice
Authors: Messer H. H. , Siner L. , Ophaug R.
Published: July 2006

The ability of a high F intake to inhibit alveolar bone loss was assessed over a period of one year in strain STR/N mice. This strain is susceptible to periodontal disease in the absence of dietary or traumatic stimuli, with progressive alveolar bone loss beginning in adulthood. Despite a very high bone F level, alveolar bone loss was not significantly different from that occurring in mice of the same strain with a low F intake. The resistance of alveolar bone to destruction does not appear to be a major factor in the progression of periodontal disease.
Effects of force application on periodontal blood circulation
Authors: Gaengler Peter , Merte Knut
Published: July 2006

The different structure and function of the systemic circulation and microcirculation in the gingiva and in the periodontal ligament in rat incisors has been demonstrated by vital microscopy. A previously developed, standardized vital microscopic technique was applied in order to assess the effects of horizontal force application to the tooth on blood circulation. In narcotized animals, the incisors were prepared for vital microscopic observation either of the periodontal ligament or gingiva, using tooth loading with forces ranging from 30 to 500 mN. The force was applied as short, intermittent forces at 5 to 30 s and as a continuous force for 10 to 180 min.

The results revealed circulatory changes which were different in the periodontal and gingival vessels. Both compression and tension in the periodontal ligament led to ischemic areas beginning in the vessels and capillaries (30 mN) and ending with the arteries (100 mN).

After continuous force application (60 min, 100 mN), the periodontal vessels showed irreversible thrombosis. Neither short, intermittent forces nor continuous force application had an effect on gingival blood circulation.
Levamisole induced enhancement of polymorphonuclear leukocyte migration in patients with periodontitis
Authors: Povolny Brian T. , Altman Leonard C. , Page Roy C.
Published: July 2006

The effect of the immunostimulatory drug levamisole on the stimulated migration of polymorphonuclear leukocytes (PMNs) from patients with periodontitis and from normal subjects was assessed. Because of previous conflicting reports on the effect of this drug on PMN chemotaxis, the conditions of the assay were first investigated using zymosan‐activated serum (ZAS) as a chemoattractant. When PMNs were suspended in a medium containing 2% bovine serum albumin and stimulated with 10% ZAS, no enhancement was observed. In contrast, levamisole had a substantial enhancing effect when the PMNs were suspended in protein‐free medium and stimulated with a 25% concentration of ZAS. Using conditions between these extremes, the effect of levamisole on the migration of PMNs from live patients with periodontitis and from a sibling of one of the above who had severe recurrent otitis media was studied. PMN migration was depressed in all of the patients; the mean value was 23.3±4.9% of normal, range 2.0–53.0%. Adding levamisole enhanced cell migration in all cases; the average enhancement for the group was 297.5±46.8% p < 0.005), range 56.0–769.0%. Enhancement was maximal at drug concentrations between 0.1 and 1 mM. Levarnisole also enhanced the migration of PMNs from some but not all normal subjects, but to a lesser degree; mean enhancement was 58.4±23.8%, range 0–136.0%. Thus, under the assay conditions used, levamisole enhanced and in part corrected the depressed migratory responsiveness of PMNs from these patients with periodontitis.
Effect of indomethacin on bone destruction during experimental periodontal disease in the hamster
Authors: Lasfargues Jean‐Jacques , Saffar Jean‐Louis
Published: July 2006

A major event in periodontitis is the destruction of alveolar processes. It is demonstrated that indomethacin (IND), an inhibitor of prostaglandin synthesis, can inhibit bone resorption in vitro. The aim of this study was to test the effect of IND on bone destruction in hamster periodontal disease. Its action was compared to calcitonin (CT), an inhibitor of osteoclastic resorption. IND decreased the macroscopic bone loss by 28% and the number of osteoclasts per mm by 55% in diseased animals but not significantly. Conversely CT reduced significantly bone loss (p<0.05) and decreased the number of osteoclasts to the control level (p<0.01). The combination of the two drugs had the same effect than CT alone on the two parameters. These results show an effect of IND on bone destruction but an inhibitory action on prostaglandin synthesis can only be hypothesized. In this model of periodontitis CT appears more effective than IND.
The polymorphonuclear leukocyte chemotactic response to Bacteroides melaninogenicus
Authors: Gale Keith M. , Powell Robin N. , Seymour Gregory J.
Published: July 2006

PMN chemotactic assays were undertaken in four groups of subjects classified on the basis of age and periodontal disease status. Assays were conducted in the absence of serum using human serum albumin (HSA), Bacteroides melaninogenicus sonicate, and LPS activated serum as chemoattractants. When analysis of variance was carried out to test for interactions between age, disease status, and chemoattractant, highly significant differences were demonstrated between HSA plus Bacteroides melaninogenicus, HSA, and the LPS activated serum (p < 0.001) with a significant reduction in the ability of PMN's from older subjects to respond to the chemoattractant (p < 0.05). Diseased subjects' PMN's did not display an increased locomotion in either the older or younger age group (p > 0.05).
Proteoglycan and collagen in porcine gingivae
Authors: Hirsch Robert S. , Wiebkin Ole W. , Thonard John C.
Published: July 2006

The sequential extractability of uronic acid containing macromolecules, proteoglycans (mucopolysaccharides), from pig gingivae under associative and dissociative aqueous conditions has been investigated. Some of the macromolecular material thus extracted formed highly insoluble precipitates following dialysis against 0.1 M‐sodium acetate. Both soluble and insoluble fractions from associative and dissociative extraction regimes were assayed for uronic acid. The residual glycosaminoglycan in the tissue was assayed following papain digestion of the tissue. The limitation of assay reproducibility for various sized source tissue indicates that at least 100 mg dry weight of gingivae is required. When epithelium was removed from the underlying gingival connective tissue, the reproducibility of hydroxyproline estimation was improved. These data emphasize that the epithelium contributes an uncontrollable variable to the basic dry weights of gingivae as a whole against which such measurements as collagen content may be assessed. Furthermore, the data generated from sequential extraction of macromolecular uronates from pig gingivae indicated that there was less susceptibility of intercellular material to dissolution under associative conditions than previously reported for human gingivae. This resistance to salt extraction implies a greater degree of macromolecular organization. In consequence, the different macromolecular structure of the pig gingival intercellular matrix may be less susceptible to degradative processes, a suggestion which is supported by the low incidence of periodontal inflammation observed in these pigs.
Inhibition of plaque formation in humans by octenidine mouthrinse
Authors: Patters M. R. , ÅNerud K. , Trummel C. L. , Kornman K. S. , Nalbandian J. , Robertson P. B.
Published: July 2006

Octenidine, a new bispyridine antimicrobial compound, has significant antiplaque activity in animals. The present study was designed to assess the effectiveness of this agent in inhibiting plaque formation in humans. Sixty males (age 22–36 years) were randomly assigned 4 formulations which included 1) 0.1% octenidine in vehicle, 2) 0.1% octenidine in aqueous solution, 3) 0.05% octenidine in vehicle, and 4) vehicle only. After establishment of minimal levels of plaque and gingivitis, each subject rinsed twice daily under supervision with his assigned test agent. Over the next seven days, the subjects were not permitted any other means of tooth cleaning. Plaque accumulation was measured daily and gingival fluid and stain levels determined on days 0 and 7.

Analysis of the data showed that both formulations of 0.1% octenidine almost completely inhibited plaque formation over the 7 day period. The vehicle had no effect on the agent's activity. The 0.05% concentration allowed some plaque accumulation, but all octenidine groups had significantly less plaque than the control group. Gingival fluid flow was significantly lower in all octenidine groups than in the control group. Tooth stain increased in all groups using the agent but remained unchanged in the group using the vehicle alone.

Results of this short term clinical trial suggest that octenidine may be a useful topical antiplaque agent.
New connective tissue attachment in beagles with advanced natural periodontitis
Authors: Bogle Gary , Garrett Steve , Crigger Max , Egelberg Jan
Published: July 2006

A pilot study using advanced, natural periodontitis in beagle dogs was performed to determine the possibility of achieving periodontal regeneration to an extent that would bring the attachment back to the original level at the cemento‐enamel junction. Nine mandibular premolars in two beagles were treated with a mucoperiostal flap procedure including citric acid conditioning of the root surfaces and coronal placement and suturing of the flaps.

Histologic examination of buccal and lingual root surfaces demonstrated new connective tissue attachment including the formation of new cementum back to or near the cemento‐enamel junction in most specimens. The mean epithelial migration apical to the cemento‐enamel junction amounted to only 0.3 mm. The formation of new crestal alveolar bone, however, was limited. The histological analyses of the furcation areas showed new connective tissue attachment in six of the nine specimens.

The result indicates that it is biologically possible to obtain new connective tissue attachment up to the original level of attachment at the cemento‐enamel junction following treatment of advanced natural periodontitis in beagle dogs. It seems to be possible to accomplish this connective tissue attachment not just in isolated areas, but at several circumferential locations on the teeth as well.
Continuous labelling of the periodontal ligament of mice
Authors: McCulloch C. A. G. , Melcher A. H.
Published: July 2006

The growth fraction in the mouse periodontal ligament (PL) was determined by means of continuous labelling for up to 60 days with 3H‐Tdr via the drinking water. The method was tested by comparing the labelling indices (LI) of PL cells obtained in this way with those obtained by repeated injections or via osmotic mini‐pumps. There was no significant difference between the LI obtained by the 3 different routes. Cell density was assayed in the PL of mice who had received no 3H‐Tdr or that were labelled for 60 days with 3H‐Tdr. There were no detectable differences in cell density, and we concluded that 3H‐Tdr cytocide did not significantly change the growth fraction. The growth fraction of PL cells was 30%, and 25 days of continuous labelling were required to obtain this value. No significant change of LI was observed between 25 and 60 days of labelling. This plateau could not be accounted for by loss of PL cells to bone as osteocytes because very few labelled osteocytes were observed, even after 25 days of continuous labelling. The growth fraction of cells within 10 μm of blood vessels was 40% and was significantly higher than the overall growth fraction. These data suggest that cell division in the PL occurs predominantly in a paravascular location and that some of the progeny of dividing cells in the PL die.
A freeze‐fracture study of the periodontal ligament of the rat
Authors: Cho Moon‐Il , Garant Philias R.
Published: July 2006

Fibroblasts of the rat periodontal ligament were studied in situ by the freeze‐fracture technique. Large surfaces of the protoplasmic and extracellular faces of the cell membrane as well as, the membranes of the RER, Golgi apparatus, and other cytoplasmic organelles were viewed at the ultrastructural level. Intramembrane particles representing membrane proteins were visualized, and their concentration in various membranes measured.

Features of the fibroblast cell surface appearing as rough patches were interpreted to represent areas of possible cell‐to‐matrix interaction. The use of the freeze‐fracture technique in further studies of PDL fibroblast‐matrix contact is discussed.
Experimental gingivitis in humans
Authors: Seymour G. J. , Powell R. N. , Cole K. L. , Aitken J. F. , Brooks D. , Beckman I. , Zola H. , Bradley J. , Burns G. F.
Published: July 2006

Cell types in a human experimental gingivitis model were analyzed sequentially on days 0, 4, 8, and 21 of a no oral hygiene period. The cells were characterized using enzyme and surface antigen markers. In all but two of the day 0 specimens a small inflammatory infiltrate was localized immediately beneath the junctional epithelium. These, essentially lymphocytic lesions, consisted of over 70% T‐cells as suggested by the phenotype T‐enzyme +ve/T‐cell surface antigen +ve/B‐cell surface antigen −ve/HLA‐DR −ve/B‐cell subset antigen −ve. At days 4, 8, and 21, although the size of the infiltrate increased, its essential nature did not change. At all times the majority of lymphocytes (over 70%) had the characteristic T‐cell phenotype. These results show that in the developing gingival lesion in humans a T‐cell dominated lesion occurs and persists at least for the 3 week experimental period used in the present study.
Assessment of plaque tenacity on enamel surface
Authors: Mehrotra K. K. , Kapoor K. K. , Pradhan B. P. , Bhusan A.
Published: July 2006

An objective methodology was employed in the present in vitro study to assess bristle pressure required for plaque removal from the enamel surface of freshly extracted teeth. This bristle pressure has indirectly reflected the plaque tenacity or total attachment force of the plaque on the tooth surface. Equipment used to measure bristle pressure was especially fabricated for this purpose and described in detail with illustrations. The mean bristle pressure required for the removal of 1‐day, 2‐day, and 3‐day old plaque was 5.509 gms/cm2, 7.757 gms/cm2 and 14.28 gm/ cm2 which shows a ratio of 5:7:13 respectively, indicating an increase in plaque tenacity as it advances in age Further, the increase in tenacity of plaque from 2‐day to 3‐day was more as compared to the increase in tenacity from 1‐day to 2‐day plaque
The effect of Octapinol on dento‐gingival plaque and development of gingivitis
Authors: Matsson L. , Klinge B. , Willard L.‐O. , Attström R. , Edwarddsson S.
Published: July 2006

The effect of a new substance (Octapinol) on the development of dento‐gingival plaque and gingivitis has been studied in beagle dogs over a one year period. Ten test and nine control animals were used. At the start of the experiment all animals had normal gingiva and clean teeth. On day 0 of the experiment all tooth cleaning procedures were abolished, and the animals were fed a diet allowing accumulation of plaque and development of gingivitis. In each of the experimental dogs one side of the mouth was randomly chosen to constitute the test side, where the test solution was applied twice daily. In one quadrant on the opposite side a placebo solution was applied. The other quadrant was used as a non‐treated control. In the control dogs a placebo solution was applied on one side while the other side was used as a non‐treated control. The gingival and periodontal alterations were determined using the following parameters: plaque index, calculus index, gingival index, amount of gingival exudate, probing pocket depth, and loss of attachment. Registrations were performed on day 0 and after 4, 8, 12, 16, 20, 24, 40, and 52 weeks. During the 52‐week experimental period it was found that the tested compound decreased the amount of plaque formed on the teeth and lowered the degree of gingival inflammation in comparison with control regions. No loss of attachment was noted in the two groups of animals. The results indicate that the tested compound counteracts the development of plaque and gingivitis during a 12‐month period of no mechanical oral hygiene in beagle dogs.
The effect of Octapinol on dento‐gingival plaque and development of gingivitis
Authors: Attström R. , Matsson L. , Edwardsson S. , Willard L.‐O. , Klinge B.
Published: July 2006

Octapinol, a compound which in previous studies has been shown to reduce plaque formation in vitro and to reduce gingivitis in vivo in dogs, was studied with regard to its effect on plaque formation and gingivitis in man.

The study was divided in two parts. In the first, 24 dental hygiene students were divided into 4 groups of equal size and starting from a plaque‐free base line were treated with 0.1–1.0% w/v aqueous solutions of Octapinol applied daily for 4 days onto the teeth on one side of the jaw while the contralaterial side was treated with a placebo solution. In the second study, 7 students starting from a plaque‐ and gingivitis‐free base line applied a 1.0% solution daily to all teeth for a 3‐week period during which time no mechanical oral hygiene was allowed. After a period of resumed oral hygiene another 3‐week period of no oral hygiene followed during which a placebo solution was applied in a similar fashion.

In the first study 0.5 and 1.0% concentrations of Octapinol significantly reduced the plaque formation during the 4‐day test period while the effect of lower concentrations was less prominent.

In the 3‐week experiment using a 1% Octapinol solution only minor development of plaque and gingivitis was noted during the test period while rapid accumulation of plaque and marked gingival inflammation occurred during the control period.
The water binding capacity of the periodontal ligament and its role in mechanical function
Authors: Ferrier J. M. , Dillon E. M.
Published: July 2006

The water binding capacity of porcine periodontal ligament samples was measured using the method of thermocouple psychrometry. The measured values for relative water capacity were 0.55 ± 0.07, 0.28 ± 0.05, and 0.20 ± 0.02 MPa−1, at water chemical potentials of −2, −3, and −4 MPa. The measured water capacity is consistent with reported values for tooth displacement at small forces, but not at larger forces. This implies that water binding in the ligament could account for the viscoelastic properties at low stress, but not at higher stress.
Minocycline reduces gingival collagenolytic activity during diabetes
Authors: Golub L. M. , Lee H. M. , Lehrer G. , Nemiroff A. , McNamara T. F. , Kaplan R. , Ramamurthy N. S.
Published: July 2006

Diabetes increases gingival collagenase activity, an effect that may be mediated by endogenous tissue changes and exacerbated by an overgrowth of Gram‐negative organisms in the gingival crevice (see Ramamurthy & Golub 1983, McNamara et al. 1982). In an attempt to reverse this collagenolytic abnormality, we administered an appropriate antibiotic, minocycline (a semisynthetic tetracycline), to diabetic rats and humans. Adult male conventional or germfree rats were made diabetic with streptozotocin, and half of these animals were administered minocycline (20 mg per day) by tube feeding for 3–4 weeks prior to sacrifice. The buccal gingiva, entire skins, and mandibles were dissected and tested for collagenolytic enzyme activity, collagen content, and alveolar bone loss, espectively. In a preliminary study, minocycline (200 mg per day) was administered for 7 days to an insulin‐dependent diabetic adolescent human and an adult non‐diabetic human; the twin brother of the diabetic was treated with penicillin. Gingival fluid collagenase activity was measured (using [3H‐methyl] collagen as substrate in a new microassay) in 8 periodontal pockets in each subject before and after antibiotic therapy. Examination of collagenase digestion products by SDS‐polyacrylamide gel electrophoresis and fluorography was also carried out. In rats, minocycline treatment: (1) suppressed the abnormally elevated collagenolytic enzyme activity in gingiva of diabetic rats, even under germfree conditions; (2) inhibited PMN leukocyte collagenase activity in vitro, an effect that was reversed by the addition of calcium ions (penicillin‐streptomycin had no effect on the activity of this enzyme); and (3) retarded the abnormal loss of skin collagen and alveolar bone in diabetic rats. In a preliminary study on humans, minocycline therapy reduced the collagenase activity of gingival crevicular fluid, an effect not produced by penicillin.

Our data suggests that (1) tetracycline therapy inhibits tissue collagenolytic enzyme activity by a mechanism al least in part unrelated to its antibacterial efficacy, and (2) this mechanism may provide a new therapeutic approach for suppressing excessive collagen resorption which occurs during periodontal disease and which can occur during other pathologic conditions.
Concentrations of serum protease inhibitors and immunoglobulins in juvenile periodontitis
Authors: Sandholm Leena , Saxén Leena
Published: July 2006

Serum alpha‐2‐macroglobulin (α2 M), IgA, IgG, and IgM concentrations in relation to the total protein as well as total and differential white blood cell counts were determined in 25 Caucasian patients, 18 females and 7 males, with juvenile periodontitis (JP). Fifteen patients, aged 15–24 years, formed the JP group and ten patients, aged 25–30 years, the post‐JP group. The α2M values were normal: means 2.91 ± 0.85 g/l in the JP group and 2.62 ± 0.56 g/l in the post‐JP group. Eight of the eleven patients in JP group and three out of ten patients in the post‐JP group showed elevated percentage lymphocyte counts, but the absolute numbers of cells were within normal range. The mean level of IgA was 2.66 ± 1.39 g/l in the JP group and 1.96 ± 1.22 g/l in the post‐JP group. The mean level of IgG was 13.08 ± 2.62 g/l in the JP group and 13.32 ± 4.88 g/l in the post‐JP group. The mean IgM was 1.86 ± 0.82 g/l in the JP and 2.30 ± 0.66 g/l in the post‐JP group. There were no statistically significant differences in the serum protein mean values between the JP and post‐JP groups. The differences between the JP or post‐JP group immunoglobulin means compared to normal means were not statistically significant.
Biological and chemical comparison of butanol‐ and phenol‐water extracted lipopolysaccharide from Capnocytophaga sputigena
Authors: Poirier T. P. , Mishell R. , Trummel C. L. , Holt S. C.
Published: July 2006

Lipopolysacharide was isolated form Capnocytophaga sputigena strain 4 by the butanol‐water method, and its release and association with acid (AcP) and alkaline (AIP) phosphatase was compared. Approximately 70% of the AcP and AIP was released with the butanol‐water extracted LPS (BLPS), with one‐third of the released phosp0hatases co‐eluting with it on Sepharose 4B. The BLPS was low in carbohydrate, KDO, lipid, heptose, hexosamine, and higher in phosphate and protein that the phenol‐water (PLPS) extracted LPS, SDS‐PAGE‐periodic acid Schiff staining revealed carbohydreate in both LPS preparations, while Commassie Blue staining revealed peptides only in BLPS, occurring as several minor bands and one major band at 39–41 kilodaltons. Immunoferritin reactions localized the LPS at the surface of intact C. sputigena; both LPSs were, however, immunochemically distinct. Incorporation of 3H‐thymidine into BLPS stimulated whole and T‐depleted C3H/HeJ mouse spleenocytes 7 and 4 fold, respectively higher than with PLPS. A phosphatase‐LPS interaction employing purified molecules was examined.
Salivary enzymes
Authors: Nakamura Masakazu , Slots Jørgen
Published: July 2006

Seventy‐six enzyme activities of mixed whole saliva, parotid saliva, serum, and polymorphonuclear leukocytes were examined in 10 individuals with healthy periodontium, 10 adult periodontitis patients, and 4 localized juvenile periodontitis patients by using the API ZYM (Analytab Products Inc., Plainview, N. Y.) and API ZYM AP (API System, La Balme les Grottes, France) semi‐quantitative micromethod systems. Enzymes assayed included phosphatases, esterase, lipase, glycosidases, and proteases including numerous aminopeptidases.

Among the three study groups, mixed whole saliva of adult periodontitis patients revealed the highest and mixed whole saliva of healthy individuals the lowest enzyme activities. Statistically significant differences were found for alkaline phosphatase, esterase, β‐glucuronidase, α‐glucosidase, and some aminopeptidases. Bacterial sediment of whole saliva exhibited higher enzyme activities than whole saliva supernatant. Serum contained numerous aminopeptidases which were virtually undetectable in whole saliva. Some enzyme activities found in mixed whole saliva could not be detected in parotid saliva. Polymorphonuclear leukocytes demonstrated a distinct enzyme profile.

The present study shows that varying enzyme profiles exist among the various components which make up whole saliva. It also indicates that numerous salivary enzymes originate from oral microorganisms and that the enzyme activity of whole saliva is higher in individuals with periodontal disease than in periodontally healthy subjects.
Acid‐soluble proteins of normal, regenerated, and periodontally diseased gingivae
Authors: Page Roy C. , Narayanan A. Sampath , Lindhe Jan , Clagett James A.
Published: July 2006

The purpose of the study was to characterize the noncollagenous acid‐soluble proteins of gingiva and to determine their function. Gingival tissues of healthy adult dogs and those with spontaneously occurring advanced periodontitis were studied. The dental laminac from newborn puppies and skin of newborn and adult animals were also analyzed. Tissues were extracted with buffered salt at neutral pH followed by 0.5 M acetic acid. SDS‐polyacrylamide gel electrophoresis revealed that salt extracts of all of the tissues contained collagens and several more rapidly migrating components; the latter cross‐reacted with an antiserum to whole dog serum and were, therefore, derived from serum and tissue fluids. The acid extracts of normal gingiva contained a family of collagenase‐resistant, pepsin‐sensitive components ranging in size from about 32 kD to 75 kD. These components did not cross‐react with the antiserum and appeared to be components of the connective tissues. They were partially purified by DEAE‐cellulose chromarography and shown to be similar to the acidic structural glycoproteins of other connective tissues. These acid‐soluble proteins were present in moderate to large amounts in extracts of healthy gingival tissues and in trace amounts in dental lamina. The amount in extracts of regenerated gingiva was much greater than in extracts of normal gingiva. Only traces were found in the extracts of gingivae from animals with spontaneous periodontitis. The data indicate that these proteins may be important structural components of the normal connective tissue matrix, and their loss during the early stages of periodontitis may be an important event in progressive tissue destruction.