bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.
Subgingival plaque control by a simplified oral hygiene regime plus local chlorhexidine or metronidazole
Authors: Khoo J. G. L. , Newman H. N. 
Published: July 2006

This study determined the effects of a simplified oral hygiene regime plus local applications of metronidazole or chlorhexidine on the subgingival microflora. Twenty‐one patients, with periodontal pockets 4 mm or deeper, underwent one session of scaling, root planing, and oral hygiene instruction (Bass method but without emphasis on interdental cleaning). Eight patients performed once daily subgingival irrigation with 0.2% chlorhexidine gluconate solution for 28 days. Thirteen patients had either 0.5% metronidazole in dialysis tubings or 40% metronidazole in acrylic resin strips inserted subgingivally once weekly, also for four weeks.For each subject, subgingival plaque was obtained from two chemically treated (test) and one non‐chemically treated (control) pockets at days 0 (prior to scaling and root planing), 7, 14, 21, 28, 56, and 84. The subgingival microflora was assessed using darkfield microscopy. Bacteria were characterized as cocci, motile organisms, spirochaetes, and others (straight and curved rods, filaments and fusiforms).Both chlorhexidine and metronidazole groups showed beneficial change still apparent at the end of the study (3 months). Great increases in proportions of cocci and reductions in spirochaetes and all other forms of bacteria were observed. Metronidazole reduced spirochaetes more but, unlike chlorhexidine, had a variable effect on motiles. Root planing alone had less effect. Generally, metronidazole and chlorhexidine appeared equally beneficial. It was concluded that in spirochaete‐dominated plaque, metronidazole may be preferred agent. Where motiles predominate, chlorhexidine may be the topical agent of choice.
Periodontal disease in three young adult populations
Authors: ÅNerud K. E. , Robertson P. B. , ÅNerud H. Löe, Å. , Boysen H. , Patters M. R. 
Published: July 2006

The purpose of the present study was to assess periodontal destruction and related etiological factors in three young adult male populations in the U. S. A., Norway, and Sri Lanka. The clinical examination included the Plaque Index (Silness & Löe 1964), Retention Index for calculus, defective fillings, and gingival caries (Löe 1967), Gingival Index (Löe & Silness 1963), and Loss of Attachment (Ramfjord 1959).Plaque accumulation, calculus deposition, and gingival inflammation were higher in interproximal than buccal areas. Plaque and Gingival Index scores remained constant over the entire age range in each population. The filling experience was high in Norway compared to the U. S. A. and Sri Lankan populations where few defective fillings were found. Caries related to the gingival margin were rare in all three populations. Loss of attachment increased with age and was greater on buccal surfaces than mesial surfaces. The distribution of attachment loss was similar in the three populations, and the greatest attachment loss involved maxillary first molars, maxillary and mandibular first premolars, and mandibular incisors. Rates of attachment loss in these young populations were low, averaging less than 0.06 mm per year.
Microscopic evaluation of root surface associations in vivo
Authors: Fine D. H. , Greene L. S. 
Published: July 2006

These preliminary studies were undertaken to test the effectiveness of a new procedure for in vivo examination of interactions between bacteria and root surfaces. For this purpose, four patients with juvenile periodontitis, four with chronic periodontitis, and four normal subjects were selected. For this procedure, root segments 8 mm long, 2 mm wide, and 150–200 μm thick were prepared from normal teeth extracted for orthodontic reasons. These root segments were then sterilized with ethylene oxide. In each subject, one root segment was placed in direct apposition to the mesial surface of a previously scaled lower first molar and positioned to extend 4–5 mm supragingivally and 2–4 mm subgingivally. Root strips were removed after seven days, fixed, dehydrated, and embedded in Spurr's resin.Light and electron microscopic examination of sections from the supragingival portion of root segments revealed bacteria within the root surface in all normal and chronic periodontitis subjects and in two juvenile periodontitis subjects. A nonpenetrating flora was associated with the supragingival portion of the root segments from the other two juvenile periodontitis subjects.Subgingivally, root segments from normal subjects were colonized by junctional epithelium with hemidesmosomes and wide intercellular spaces in which bacteria and polymorphonuclear leukocytes were occasionally seen. In root segments from chronic periodontitis patients, the surface appeared to be occupied by Gram (+) bacteria that were morphologically similar to those seen supragingivally in samples from the same patients. Polymorphonuclear leukocytes and a sparse, loosely associated flora was present on the surface of the subgingival portion of the root samples from juvenile periodontitis patients.The contrast between the presence of bacteria within the supragingival and subgingival portions of root segments obtained from chronic periodontitis patients and the absence of bacteria in root segments from all subgingival samples and two supragingival root samples in the juvenile periodontitis group was considered the most provocative result of the study. It was concluded, on the basis of these results, that the procedure used for the preparation and placement of root segments overcomes limitations inherent in other techniques for the study of subgingival events and permits clear discrimination between patterns of bacterial colonization of the root surface in different subject populations.
Relationship between linear and area measurements of radiographic bone levels utilizing simple computerized techniques
Authors: Jeffcoat M. K. , Williams R. C. 
Published: July 2006

Three methods were used to measure the percent alveolar bone remaining about the premolar teeth in standardized perapical radiographs from eight female beagle dogs. The first method utilized straight‐line measurements of bone remaining along the tooth root, the second method used measurements which followed the curved path of the tooth root, and the third method measured the area of tooth root supported by alveolar bone as projected on a radiograph.An inexpensive digitizer‐computer system was used to determine linear, curvilinear, and area measurements. The percent remaining alveolar bone determined by each of these three methods were compared in order to determine the simplest technique which most completely describes the bone remaining about each tooth root. There was no significant difference between the percent bone remaining determined by straight line and curvilinear measurements. Similarly, there was no significant difference between straight line and area measurements of percent remaining alveolar bone when there was little loss of alveolar bone (<15%). However, when there was moderate to severe bone loss on the radiograph (>15% loss), area measurements were significantly lower than linear measurements. The relationship between area measurement and linear measurement may be described by a quadratic equation. These data indicate that simple linear measurements of percent remaining alveolar bone on a radiograph may be transformed to the more complete area description of percent remaining alveolar bone using a quadratic equation. Thus, in beagles, simple linear measurements of percent remaining alveolar bone may be used to provide as complete a description of radiographic support as the more complex area measurements.
Histopathological effects in the palate of the rat induced by injection with different black‐pigmented Bacteroides strains
Authors: Roeterink C. H. , van Steenbergen T. J. M. , de Jong W. F. B. , de Graaff J. 
Published: July 2006

The present investigation was carried out in order to study the histopathological effect and virulence of different black‐pigmented Bacteroides species on both soft and hard tissues in an animal model. Male Wistar rats were injected in the palate next to the first right molar with 30 μl of a bacterial suspension containing 5 × 1010 viable cells per ml. To determine the difference in virulence the histopathological effects were studied five days after injection.All strains tested caused a submucosal infiltrate at the injection site, consisting of mononuclear cells, mainly lymphocytes, monocytes and fibroblasts. These inflammatory responses were accompanied by devitalization and resorption of bone. Simultaneously active osteoblasts and bone formation were observed. Strains of Bacteroides asaccharolyticus, Bacteroides melaninogenicus, Bacteroides corporis, and Bacteroides loescheii caused a less prominent devitalization of the palatinal bone than strains of Bacteroides gingivalis and Bacteroides intermedius. Strains of the latter species caused often a nasal infiltrate and abundant bone formation at the nasal side of the palatinal bone. B. asaccharolyticus and B. melaninogenicus scarcely caused signs of a reaction at the nasal side of the palatinal bone.In a second longitudinal study the histopathological effects of B. gingivalis strain HG 66 were investigated. The inflammation was characterized by a rapid influx of polymorphonuclear cells within 2 to 4 hours. These cells gradually diminished and were replaced by a mononuclear infiltrate. One of the most characteristic features accompanying the inflammation was the disappearance of the periosteum. After two days a recovery of periosteum was observed and the osteoblasts became active in new bone formation. Devitalization from the palatinal bone started about 8 hours after injection and could be seen until 10 days after injection. No inflammatory reaction or devitalization of bone could be observed 15 days after injection.
Reliability of volume measurements with the new Periotron® 6000
Authors: Bickel Matthias , Cimasoni Giorgio 
Published: July 2006

A new device, the Periotron 6000®, has been proposed to estimate small amounts of gingival crevicular fluid. In the present investigation, small volumes of four different liquids (saline, saliva, plasma, and crevicular fluid) collected with small capillaries have been delivered on to Periopaper® strips. The amounts of liquids on the strips were determined with the Periotron.High correlations between the fluid volumes and the Periotron readings were found. A calibration curve of the measurements made with crevicular fluid with its 5% tolerance and confidence limits is given. The slope of linear regression found in our investigation was at 3.5 nl per unit, thus significantly below that described by the manufacturer (5 nl/unit). Taking into account this fact, the Periotron, however, is a very reliable device to study gingival crevicular fluid in clinical investigations.
Age and diet composition in relation to experimental periodontal destruction in hamsters
Authors: Mikx F.H.M. , Maltha J.C. , Wolters‐Lutgerhorst J.M.L. , Franken H.C.M. 
Published: July 2006

Hamsters from 30 days upto 150 days of age were used to study the effect of different dietary regimens, including pellets, powdered pellets, and powdered purified diets with and without sucrose. The experimental period was 30 days. The periodontal destruction was measured macroscopically and histologically while bone remodelling was scored using Procion Brilliant Red® as a marker. Plaque amount, infiltrate, and osteoclasts were evaluated in the histological sections. Actinomyces, Propionibacterium, Veillonella, Fusobacteria, and Bacteroides were identified in most plaque samples. Spirochetes were never observed. The texture of the diet had neither an effect on the amount of dental plaque nor on the bone level measurements. The difference in bone level was related with the presence of sucrose in the diet and the age of the hamsters. Animals of 30 days old at the start of the experiment showed, in contrast to the older animals, no difference in bone level after the experimental period.It is concluded that in hamsters on a 16% sucrose diet the growth of alveolar bone is diminished, or even the destruction of alveolar bone is induced. This process in hamsters is age related and might be analogous to that in man.
Necrotizing ulcerative gingivitis in beagle dogs
Authors: Mikx F.H.M. , Hug H.U. , Maltha J.C. 
Published: July 2006

The induction and transmission of Necrotizing Ulcerative Gingivitis (NUG) lesions in beagle dogs have been reported previously. In the present experiments the contagious nature of these NUG lesions was further investigated by studying the unilateral induction and the intraoral transmission of NUG lesions. Six beagle dogs were treated with Kenacort A40®. The control quadrants of their dentition were cleaned while the experimental quadrants were not. The experimental quadrants were inoculated with pooled dental debris from the same dogs. NUG lesions were induced in the experimental quadrants, but NUG lesions were observed also at some sites of the control quadrants. In the second part of the experiment, reinoculation of non‐affected experimental sites with debris from lesions of the same dog or cage companion increased the number of NUG lesions in both experimental and control quadrants.The study of experimental intraoral transmission of NUG lesions was restricted to the non‐diseased sites in experimental and control quadrants. Topical application of debris of NUG lesions on the test sites did not spread the disease to these sites. Microscopic and cultural evaluation of subgingival microflora revealed no differences in the presence of Bacteroides, Fusobacteria, Spirocheata, and Spirillum in relation to the presence or absence of NUG. Three different types of black pigmental Bacteroides species were observed. It is concluded, that the morphology of the interdental sites is of great importance for the clinical occurence of NUG lesions and that the increase in number and severity of lesions after local reinoculation indicates that in the phase of primary infection, iatrogenic NUG lesions might be possible in a susceptible host.
Necrotizing ulcerative gingivitis in beagle dogs
Authors: Hug H.U. , Maltha J.C. , Mikx F.H.M. 
Published: July 2006

Clinical studies in beagle dogs have indicated that NUG occurs at sites of predilection. The purpose of the present investigation was to compare the histologic characteristics of interdental sites exhibiting clinical NUG with those without clinical NUG in relation to the presence or absence of interproximal contacts.In six beagle dogs, aged three years, NUG was experimentally induced. At the end of a longitudinal clinical study the dogs were sacrified and prepared for histological evaluation. The occurrence of ulcerations in the col epithelium and the adjacent epithelium is related to the clinical NUG scores as well as to the presence of interproximal contact. The same holds true for the presence of an inflammatory infiltrate in the subjacent connective tissue. Ulcerations of the col epithelium as well as the infiltrate subjacent to this area appears to be related to the clinical NUG scores, but the ulcerations in the sulcular and junctional epithelium are not, nor is the infiltrate subjacent to these epithelial areas.The results suggest two possibilities. The first is that the clinical NUG score is insufficient to trace the sulcular expression of the disease, and the second possibility is the existence of two different periodontal diseases in these beagle dogs.
The effect of notching and citric acid on healthy root surfaces in dogs
Authors: Gara George G. , Adams Donald F. 
Published: July 2006

The purpose of this study was to determine the following on healthy root surfaces: (1) the effect of placement of a notch within dentin on the formation of cementum and/or connective tissue attachment and (2) the effect of citric acid on the notched root surface on the formation of cementum and/or connective tissue attachment. Five young adult dogs were used in the study. Full thickness buccal flaps were reflected on canines, P3, P4, and M1, 4 mm of buccal bone was removed, and the roots carefully planed. One, two, or three parallel notches were placed in the exposed root surface of each tooth. The root surfaces were then treated with either citric acid or saline, and the flaps were replaced and sutured. Animals were sacrificed at intervals of 5 weeks, 9 weeks, 10 weeks, and 12 weeks. Block specimens were examined in step‐serial fashion via light microscopy. The data pool consisted of 19‐matched paired teeth, including 72 roots. Healing responses in a specific notch or on an isthmus varied, including epithelium‐root, connective tissue‐cementum‐root, bone‐connective tissue‐root, ankylosis, or any combination.There was a statistically significant increase in the formation of connective tissue attachment, cementum, and bone toward the apical part of the notches and isthmuses. Epithelium interfaces were significantly higher in notches compared with isthmus surfaces (α= 0.05). The frequency of connective tissue attachment on isthmuses was statistically greater than in notches (α= 0.05). When citric acid was used, in comparison to saline, cementum was observed significantly more often in the coronal portion of the lesions (α= 0.05). This study indicates that citric acid applied to healthy root surfaces in dogs enhances cementum formation in areas farther coronally to the alveolar process than areas treated with saline. Notching per se does not enhance cementum and/or connective tissue attachment. There was no difference in the incidence of ankylosis between saline and citric acid treated specimens.
In vitro sorption of IgG to cementum
Authors: Fine D. H. , Wilton J. M. A. , Caravana C. 
Published: July 2006

The nature of the interaction between root surfaces and gingival fluid proteins has not been studied. Therefore, a series of in vitro investigations were undertaken to develop an assay to determine sorption of prominent gingival fluid proteins to the cementum.In initial studies extracted teeth were immersed in various concentrations of whole human serum and incubated with rabbit anti‐IgG, IgA, IgM, and C3 followed by anti‐peroxidaseperoxidase bridging reagents. Of the proteins analysed IgG sorbed to the highest degree in gross and microscopic evaluations. Remaining studies focused on quantifying IgG sorption, and thus root segments of known surface area were prepared and immersed in 125I‐IgG. Sorption of IgG was calculated as 21.5 ± 0.27 ng/mm2 when IgG was added at concentrations found in gingival fluid. Root fragments immersed in non‐IgG human serum reconstituted with specific amounts of 125I‐IgG, sorped only 3.4 ± 0.9 ng/mm2 of IgG, and direct measurement of IgG sorption in whole serum by the ELISA method gave comparable results. Moreover, pre‐coating of root segments with non‐IgG serum followed by incubation with 125I‐IgG resulted in 74% inhibition of IgG binding.Results suggest that serum protein sorption to root surfaces can be quantitated and may be non‐specific and concentration dependent with respect to IgG.