A bibliometric analysis of periodontology

This bibliometric study assessed periodontal/implant articles that were part of the five most‐cited dental articles in each of the years 2005‐2019. Periodontal/implant articles made up one to four articles in each of 14 years and totaled 40% of the yearly five most‐cited dental articles. The three core periodontal journals (Journal of Clinical Periodontology, Journal of Periodontology, and Periodontology 2000) increased ~50%‐100% in Journal Impact Factor from 2005 to 2015 and were among the 10 most‐cited dental journals in the 2015‐2019 period. The Journal of Clinical Periodontology and Periodontology 2000 were in several years assigned the highest Journal Impact Factor in dentistry. In summary, periodontal journals continue to publish high‐impact articles that are relevant for both oral health care and medicine.     

Purification and characterization of the serotype c antigen from Actinobacillus actinomycetemcomitans.

The serotype c antigen from Actinobacillus actinomycetemcomitans was purified with fractional ethanol precipitation of cell-free culture supernatant, sequential ion-exchange chromatography, and gel filtration chromatography. The preparation obtained demonstrated a single precipitin line in immunodiffusion, immunoelectrophoresis, and crossed immunoelectrophoresis when rabbit antisera to serotype c whole bacterial cells were used. No immunological reaction was detected with antisera to serotype c lipopolysaccharide, indicating that lipopolysaccharide was not present in the preparation. The serotype c antigen was composed of 95% carbohydrate, 2% protein, and 3.1% phosphate. Gas chromatographic analysis of the antigen obtained from growth in either complex or chemically defined media revealed that the carbohydrate constituent was composed of 84 to 90.1% mannose, 4.8 to 16% glucose, 1.9% N-acetylglucosamine, 1.4% fucose, and 0.2% galactose. The present data suggest that A. actinomycetemcomitans serotype c antigen is predominantly a mannose-containing carbohydrate suggestive of a mannan.     

Antigenic characteristics and serological identification of 10 black-pigmented Bacteroides species.

Strains of 10 black-pigmented Bacteroides species were serologically characterized using absorbed and unabsorbed rabbit antisera. An agglutination test using intact cells or heated cells (100 degrees C for 60 min) from each species and unabsorbed antisera revealed only homologous reactions with little or no reactivity in heterologous assays. Immunodiffusion tests using sonicated antigen demonstrated that Bacteroides gingivalis, B. endodontalis, B. asaccharolyticus, B. macacae, and B. levii are antigenically distinct. Strains of B. gingivalis, B. endodontalis, and B. asaccharolyticus were also clearly identified by the indirect immunofluorescent antibody method. B. intermedius, B. corporis, B. loescheii, B. melaninogenicus, and B. denticola possessed common antigens; however, species-specific antigens detectable with immunoabsorbed antisera were also demonstrated. B. intermedius strains isolated from the human oral cavity included at least two serogroups. In each black-pigmented Bacteroides species, lipopolysaccharide constituted one of the species-specific antigens.     

Periodontal herpesvirus morbidity and treatment

Four billion individuals worldwide have a history of periodontitis, with the poorest people in society most affected. Periodontitis can lead to unsightly drifting of teeth and tooth loss that may interfere with the wellbeing of daily living and has also been linked to at least 57 medical diseases and disabilities. The etiology of severe periodontitis includes active herpesviruses, specific bacterial pathogens, and destructive immune responses, but herpesviruses seem to be the major pathogenic determinant. Periodontal herpesviruses that disseminate via the systemic circulation to nonoral sites may represent a major link between periodontitis and systemic diseases. Current treatment of periodontitis focuses almost exclusively on bacterial biofilm and will require revision. Periodontal therapy that targets both herpesviruses and bacterial pathogens can provide long‐term clinical improvement and potentially reduces the risk of systemic diseases. Molecular diagnostic tests for periodontal pathogens may enable early microbial identification and preemptive therapy. This review details an efficient and reliable anti‐infective treatment of severe periodontitis that can be carried out in minimal time with minimal cost.     

Periodontal herpesviruses: prevalence,pathogenicity, systemic risk

Periodontitis is an infectious/inflammatory disease characterized by the loss of periodontal ligament and alveolar bone. Herpesviruses are frequent inhabitants of periodontitis lesions, and the periodontopathogenicity of these viruses is the topic of this review. In 26 recent studies from 15 countries, subgingival cytomegalovirus, Epstein–Barr virus and herpes simplex virus type 1, respectively, yielded median prevalences of 49%, 45% and 63% in aggressive periodontitis, 40%, 32% and 45% in chronic periodontitis, and 3%, 7% and 12% in healthy periodontium. An active herpesvirus infection of the periodontium exhibits site specificity, is a potent stimulant of cellular immunity, may cause upgrowth of periodontopathic bacteria and tends to be related to disease‐active periodontitis. Pro‐inflammatory cytokines induced by the herpesvirus infection may activate matrix metalloproteinases and osteoclasts, leading to breakdown of the tooth‐supportive tissues. The notion that a co‐infection of herpesviruses and specific bacteria causes periodontitis provides a plausible etiopathogenic explanation for the disease. Moreover, herpesvirus virions from periodontal sites may dislodge into saliva or enter the systemic circulation and cause diseases beyond the periodontium. Periodontal treatment can diminish significantly the periodontal load of herpesviruses, which may lower the incidence and magnitude of herpesvirus dissemination within and between individuals, and subsequently the risk of acquiring a variety of medical diseases. Novel and more effective approaches to the prevention and treatment of periodontitis and related diseases may depend on a better understanding of the herpesvirus–bacteria–immune response axis.     

Low-cost periodontal therapy

Periodontitis is a complex infectious disease that affects low‐income individuals disproportionately. Periodontitis is associated with specific bacterial species and herpesviruses, and successful prevention and treatment of the disease is contingent upon effective control of these pathogens. This article presents an efficacious, highly safe, minimally invasive, practical and low‐cost periodontal therapy that involves professional and patient‐administered mechanical therapy and antimicrobial agents. The major components are scaling for calculus removal, periodontal pocket irrigation with potent antiseptics, and treatment with systemic antibiotics for advanced disease. Povidone‐iodine and sodium hypochlorite have all the characteristics for becoming the first‐choice antiseptics in the management of periodontal diseases. Both agents show excellent antibacterial and antiviral properties, are readily available throughout the world, have been safely used in periodontal therapy for decades, offer significant benefits for individuals with very limited financial resources, and are well accepted by most dental professionals and patients. Four per cent chlorhexidine applied with a toothbrush to the most posterior part to the tongue dorsum can markedly reduce or eliminate halitosis in most individuals. Systemic antibiotics are used to treat periodontopathic bacteria that are not readily reached by topical therapy, such as pathogens within gingival tissue, within furcation defects, at the base of periodontal pockets, and on the tongue, tonsils and buccal mucosae. Valuable antibiotic therapies are amoxicillin‐metronidazole (250 mg of amoxicillin and 250 mg of metronidazole, three times daily for 8 days) for young and middle‐aged patients, and ciprofloxacin‐metronidazole (500 mg of each, twice daily for 8 days) for elderly patients and for patients in developing countries who frequently harbor enteric rods subgingivally. Scaling to remove dental calculus and the prudent use of inexpensive antimicrobial agents can significantly retard or arrest progressive periodontitis in the great majority of patients.     

Frequency-Dependence of the Metabolism of 3H-Noradrenaline Released from Rabbit Isolated Aorta: Effects of a Combination of Cocaine and Corticosterone or Hydrocortisone

Abstract The effect of cocaine (neuronal uptake inhibitor) in combination with either hydrocortisone or corticosterone (extraneuronal uptake inhibitors) on the metabolism of ³H-noradrenaline (³H-NA) released spontaneously or by electrical-field stimulation was studied on the isolated rabbit aorta preloaded with ³H-NA. In the spontaneous outflow ³H-O-methylated and deaminated metabolites (³H-OMDA) accounted for 41% of the total radioactivity whereas ³H-NA represented only 22%. Cocaine (3 × 10^-5M) + hydrocortisone (10^-4 M) neither changed the spontaneous outflow of total tritium nor the distribution of the ³H-outflow on ³H-NA and its ³H-metabolites. However, cocaine (3 × 100^-5M) + corticosterone (4 × 10^-5M) enhanced the passive ³H-outflow, increased the percentage recovered as ³H-3,4-dihydroxyphenylglycol (³H-DOPEG), and reduced the percentage of ³H-OMDA + ³H-NMN. The effect of field-stimulation was investigated during and ofter stimulation at two frequencies: 3 and 10 Hz. The stimulation-induced ³H-overflow consisted mainly of unmetabolized ³H-NA and ³H-OMDA in the sample collected during stimulation. The ratio between ³H-NA and ³H-OMDA was strongly dependent on the frequency of stimulation, Thus it was 1:2 at 3 Hz, but 3:1 at 10 Hz. These ratios were about the same during the poststimulation period. On the other hand, whereas the formation of ³H-DOPEG from ³H-NA released during stimulation at both frequencies was small, it increased rapidly in the poststimulation sample. At 3 Hz, inhibition of neuronal and extraneuronal uptake by cocaine + steroids did not change the stimulation-induced ³H-overflow, but the distribution on ³H-NA and ³H-metabolites was markedly altered. Thus the percentage of ³H-N A was doubled, ³H-OMDA was halved, and ³H-DOPEG was almost abolished. At 10 Hz, however, cocaine + corticosterone decreased the stimulation-induced ³H-overflow, but did not change the proportions of ³H-NA and ³H-OMDA. Only the formation of ³H-DOPEG was markedly reduced. It is concluded that the distribution of stimulation-induced ³H-overflow on ³H-NA and its ³H-metabolites and the effect of neuronal and extraneuronal uptake inhibition on this is strongly influenced by the frequency of stimulation. Furthermore, inhibition of both neuronal and extraneuronal uptake does not fully prevent metabolism of ³H-NA released by electrical-field stimulation.     

Cytomegalovirus infection in symptomatic periapical pathosis

AIM: To compare the presence of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) infections in samples from 25 symptomatic and 19 asymptomatic periapical lesions. METHODOLOGY: Periapical samples were collected by sterile curettes in conjunction with apicectomy. cDNA-based HCMV and EBV identification was performed on total mRNAs extracted from peripapical tissues, using primers for genes transcribed during the productive phase of the herpesvirus infection. Statistical analysis was performed using chi-squared test. RESULTS: HCMV was detected in 100% of the symptomatic and in 37% of the asymptomatic study lesions. EBV was identified only in HCMV-infected periapical lesions. The difference in occurrence of HCMV and EBV between symptomatic and asymptomatic periapical lesions was statistically significant (P < 0.0001). CONCLUSIONS: The noteworthy finding of this study was the ubiquitous occurrence of HCMV active infection in symptomatic periapical pathosis. EBV may contribute to periapical pathogenesis in a subset of symptomatic lesions. HCMV and EBV infections may cause periapical pathosis by inducing cytokine and chemokine release from inflammatory or connective tissue cells, or by impairing local host defences resulting in heightened virulence of resident bacterial pathogens. Knowledge about the role of herpesviruses in periapical pathosis seems important to fully delineate the pathogenesis of endodontic infectious diseases. HCMV and probably EBV should be added to the list of putative pathogenic agents in symptomatic periapical disease.