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Surgical pocket therapy.

(1) Periodontal pockets can be treated successfully by several modalities of surgery. (2) Periodontal pocket walls do not have to be eliminated surgically in order to stop the progress of periodontal disease. (3) A residual defect which can be probed beyond 3 mm at the site of a previous peridontal pocket, does not signify a progressive lesion as long as it does not appear inflamed or contain, exudate and bleeds when probed. (4) The most important aspect of all pocket therapy is to make the exposed root surface biologically acceptable to the surrounding soft tissues. (5) The gingiva should be so closely adapted to the teeth at the end of the healing following treatment that subgingival plaque does not colonize to the extent of being recognizable clinically. (6) Frequent professional prophylaxis is of paramount importance for success of all pocket therapy.

Alveolar Process

Subgingival microflora of periodontal patients on tetracycline therapy.

Samples of subgingival plaque were collected from periodontal patients receiving two different tetracycline treatment regimens following conventional periodontal therapy. Four patients had received an oral dose of 1000 mg/day for 2 weeks and nine had received 1000 mg/day for 1 week followed by 250 mg/day for extended time periods. The latter regimen is similar so that commonly prescribed for the chronic skin disease, acne vulgaris. Taxonomic characterization of plaque isolates indicated that the predominant organisms cultured from both treatment groups were species of Streptococcus and the branching, filamentous Gram-positive rods, Actinomyces and Rothia. A much greater microbial complexity was observed among the flora isolated from patients taking 250 mg/day. The latter group harbored many of the fastidious Gram-negative organisms presently implicated in the etiology of periodontal disease. All bacterial strains isolated were tested for resistance to tetracycline by replica-plating cultures on an agar medium containing two-fold dilutions of the antibiotic. Streptococcus, Veillonella and Neisseria were the bacterial genera found to be consistently resistant to tetracycline, with minimum inhibitory concentrations as high as 128 micrograms/ml. Among the Actinomyces, selection for antibiotic resistance was common only within a single species, A. odontolyticus. However, A viscosus strains isolated at 54% of the subgingival flora from one patient did demonstrate an intermediate resistance level, growing on concentrations up to 8 micrograms/ml. Tetracycline resistance was shown by a variety of Gram-negative rods isolated from the low dosage group. Although a minimum number of patients were studied, extensive microbial analyses of the predominating subgingival bacteria indicated that the goal of tetracycline therapy was achieved during the 2-week therapy period at 1000 mg/day.

Actinomyces

Cross-kingdom dynamics of the subgingival bacteriome and mycobiome: A pilot study on the effects of a novel HA-H₂O₂-Glycine formulation to treat periodontitis.

OBJECTIVES: Traditional periodontal therapy primarily focuses on bacterial biofilm control; however, recent evidence also suggests a critical role for the oral mycobiome. This study evaluated the clinical and ecological impact of a novel mouthwash formulation containing hyaluronic acid (HA), hydrogen peroxide (H2O2), and glycine on periodontal patients METHODS: This prospective, randomized split-mouth trial included 13 adult participants with periodontitis treated with HA-H2O2-glycine formula (BMG0703A) used twice a day for seven days. Subgingival plaque samples were collected from periodontal pocket and healthy control sites at baseline (T0) and one-week post-treatment (T1). Microbial and fungal communities were characterized using Next-Generation Sequencing (NGS) of the 16S rRNA and ITS2 regions. Linear Mixed Models (LMM) and Spearman correlation were used to assess taxonomic shifts and cross-kingdom relationships. RESULTS: Sequencing revealed a promising ecological shift: the bacteriome shifted from anaerobic dominance (Olsenella, Peptostreptococcus) toward a health-associated aerobic profile, with Rothia near-doubling (11.91% to 22.68%). The mycobiome underwent a "normalization" effect: Candida abundance decreased significantly (22.8% to 9.1%), while fungal Shannon diversity in pockets returned to healthy-site levels. Inter-kingdom analysis identified antagonistic relationships between expanding commensal bacteria and opportunistic fungi, suggesting that the intervention may help re-establish a protective bacterial niche. CONCLUSIONS: The HA-H2O2-glycine formulation seems to facilitate a rapid, cross-kingdom modulation of the subgingival niche. By reducing anaerobic pathogens and normalizing the mycobiome it appear to induce short-term changes, suggesting potential as adjunctive strategy in periodontal management. CLINICAL SIGNIFICANCE: The present work underlines the possible cross-Kingdom effects of a novel compound.

Humans

Histologic characteristics of experimental gingivitis in the juvenile and adult beagle dog.

An earlier study (Matsson & Attström 1979) revealed an unexplained difference between juvenile and adult dogs in the propensity to develop clinical signs of gingivitis. The aims of the present investigation were to depict the structural composition of clinically normal gingiva and to analyze the histologic changes in the gingiva during plaque development in juvenile and adult dogs. Six beagle dogs were used. Two periods of discontinued oral hygiene were studied, the first at 3 and the second at 12 months of age. Biopsies were sampled on days 0, 4, 7, 14, 21 and 28 of each period. Sections from the biopsies were analyzed at two levels of magnification. Compared to adult dog gingiva, juvenile gingiva seemed to display: 1) a thicker keratinized layer of the oral epithelium, 2) a junctional epithelium that structurally resembles the oral epithelium, 3) a cuticular structure at the surface of the junctional epithelium, 4) a limited mononuclear inflammatory cell response during experimental gingivitis, and 5) a delayed establishment of an infiltrated connective tissue portion during experimental gingivitis. In addition, during experimental gingivitis, subgingival plaque formed along the tooth surfaces to a lesser extent in the juvenile stage compared to adult dogs.

Age Factors

Effects of subgingival restorations in beagle dogs. Part II: Gingivitis.

For the materials and time period used in this study it was found that: 1. At the end of the study there were no significant differences recorded between the restored teeth with either the gingival index or the histologic inflammation index. 2. The gingival index showed that during the study the overall gingival health of the control teeth had improved significantly, while the overall gingival health of the restored teeth had improved only slightly. 3. At the end of the study the histologic inflammation index, but not the gingival index, showed significantly more gingivitis overall for the restored teeth than for the control teeth. 4. A comparison of the gingival, histologic inflammation, and microorganism (from Part I) indices, used to assess either the gingival condition or the amount of subgingival plaque on the restored teeth, showed no association between any of them. 5. In general, the degree of clinical and histologic gingivitis associated with the restored teeth was slight.

Acrylic Resins

Reagin-like activity of serum in human peridonotal disease.

The serum from patients with periodontitis produced a passive cutaneous anaphylaxis reaction in monkeys when tested against subgingival plaque. This detection of reaginic antibodies shows that patients with periodontitis make immunoglobulin E antibodies to plaque constituents.

Animals

Colonization of the cementum surface of teeth by oral Gram-negative bacteria.

By using in vitro assays, a group of related, filamentous gram-negative bacteria isolated from subgingival plaque deposits of patients with periodontal disease were found to colonize intact teeth. Tentatively identified as members of the genus Cytophaga, these isolates exhibited a preference for colonizing the cementum surface of the root. Examination of intact teeth after several weeks of colonization revealed that the root substructure had been extensively demineralized.

Culture Media

Microbial composition of monkey dental plaque (Macaca arctoides and Macaca fascicularis).

The supragingival and subgingival dental plaque flora of Macaca arctoides and Macaca fascicularis monkeys were examined using mylar strip impressions, direct smears, and culture techniques. In smears, samples generally contained 40--50% cocci, 20--30% rods 8--20% fusiform bacteria, and 4--5% each of filaments, vibrios and spirochetes. Differences in the ratios of the various bacterial groups related to age and sex were found. Several monkey bacterial species were similar to those in human dental plaque. The present results indicate that the Macaca female monkey can be a suitable animal model for the experimental studies of dental diseases.

Aerobiosis

Performance of MALDI-TOF MS for human Capnocytophaga identification verified by whole-genome sequencing.

OBJECTIVE: This study aims to evaluate the performance of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for species identification of human Capnocytophaga and to confirm results by whole-genome sequencing. METHODS: Six reference strains, representing human Capnocytophaga species and one taxon, and a total of 126 clinical strains, selected based on their biochemical profiles from a large collection of preliminarily identified Capnocytophaga isolates, were analyzed. RESULTS: Of those, 125 strains (94%) were identified at least at the genus level (log score variation of 1.7-1.999), while 52 strains (39%) were identified at the species level with a cut-off score of &#x2265;2.0. Eight strains (6%) remained unidentified with a log score of <1.69. C. leadbetteri and Capnocytophaga genospecies AHN8471 strains were accurately identified at the genus level. Minor identification errors were observed in three cases: C. leadbetteri (n=1), C. ochracea (n=2), and Capnocytophaga genospecies AHN8471 (n=38). MALDI-TOF MS was unable to distinguish between C. sputigena and Capnocytophaga genospecies AHN8471 at the species level but clustered them together in the Main Spectra Profile (MSP) dendrogram. CONCLUSIONS: MALDI-TOF MS shows promise as a diagnostic tool for identifying human Capnocytophaga species when correct taxonomy and sufficient reference strains are available in the database. Based on the close phenotypic, ribosomal, and genotypic structures, we propose to establish the term "C. sputigena group" encompassing C. sputigena, Capnocytophaga genospecies AHN8471, and other related Capnocytophaga variants. Nevertheless, updating and expanding the MALDI-TOF MS reference database is essential to improve identification accuracy.

Capnocytophaga spp.

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

Amalgam restorations, plaque removal and periodontal health.

A total of 156 approximal subgingival amalgam overhanging margins were assessed in the buccal segments of 13 patients for plaque accumulation, gingival inflammation, pocket depth and gingival shrinkage. Recordings were made immediately before and 2, 4 and 8 weeks following scaling, removal of overhangs, and oral hygiene instruction. Surfaces with overhangs were compared with control surfaces, which were either intact or contained supragingival amalgams. Initially it was found that gingival inflammation and pocket depth were more extensive adjacent to subgingival amalgam overhangs than to sound teeth or those with supragingivally located amalgams. This appeared to be due to preferential plaque accumulation in relation to subgingival overhangs. For all parameters compared, differences apparent at the baseline had disappeared by the end of the 8-week study period. Contouring of defective subgingival restorations, followed by effective scaling and oral hygiene instruction produced approximately 1 mn of gingival shrinkage, sufficient in most cases to produce clinical gingival health. Of the 156 subgingival fillings 83 (53%) became supragingival and 43 (28%) reached the gingival crest by the end of the 8-week study period.

Dental Amalgam

Clinical studies of plaque control agents: an overview.

Dental plaque is massed packed bacterial cells which accumulate on the supra- and subgingival surfaces of the teeth as well as on the oral mucosa. The microorganisms of plaque have been shown to be associated with both dental caries and periodontal disease. This overview of clinical studies of plaque control agents reviews the properties and effects of chemical compounds which have demonstrated a potential for the control of plaque microorganisms. The search for clinically effective antiplaque agents has been stimulated by findings in laboratory and animal studies of plaque dynamics. Based upon these in vitro and in vivo experiments, chemotherapeutic agents such as antibiotics, antiseptics, enzymes, detergents, bacteriosides, antimetabolites, and oxidizing agents have been evaluated against human plaque microorganisms using the ultimate biological model -- man. Continued study of chemotherapeutic agents should be encouraged because many of these drugs have been shown to be safe for human use and may require only the development of a delivery system to potentiate their concentration in a specific local site. Use of these chemotherapeutic agents, which can be self-administered, becomes an attractive way of providing the public with a cost-effective method of preventing caries and periodontal disease.

Animals

The effect of placement of cervical margins of class II amalgam restorations on plaque accumulation and gingival health.

The effects or restoring early proximal carious lesions were investigated in a series of thirty-six surfaces. In eighteen lesions the cervical margins of the restorations extended subgingivally, and in eighteen the margins were located supragingivally. Three months after restoration, plaque accumulation was not significantly different from pre-restoration levels. The degree of gingival inflammation showed a significant improvement after restoration where cervical margins were finished supragingivally (P less than 0.5). Where margins were finished subgingivally a highly significant deterioration in gingival health occurred (P less than 0.1).

Adolescent

Ultrastructure of the subgingival microflora in juvenile periodontitis.

The ultrastructure of the subgingival deposits on the root surfaces of teeth affected by juvenile periodontitis was studied on 12 teeth from nine individuals, 15--30 years of age. The deposits consisted of either microbial masses associated with a pellicle, or of a cuticular material almost free of bacteria. Gram-negative rods and filaments were the predominant microorganisms. "Corncob" configurations consisting of filamentous bacteria surrounded by Gram-positive cocci, and "bristle brush" formations comprising corncobs surrounded by long rods were observed in the superficial layer of the plaque. Spirochetes and flagellated rods constituted a major segment of the microflora. The present data indicated that the deep pockets in juvenile periodontitis harbor a sparse but relatively characteristic microbial population.

Adolescent