Fluctuations in crevicular and salivary anti-A. viscosus antibody levels in response to treatment of gingivitis

A scoping review on bio-aerosols in healthcare and the dental environment

Background

Bio-aerosols originate from different sources and their potentially pathogenic nature may form a hazard to healthcare workers and patients. So far no extensive review on existing evidence regarding bio-aerosols is available.

Objectives

This study aimed to review evidence on bio-aerosols in healthcare and the dental setting. The objectives were 1) What are the sources that generate bio-aerosols?; 2) What is the microbial load and composition of bio-aerosols and how were they measured?; and 3) What is the hazard posed by pathogenic micro-organisms transported via the aerosol route of transmission?

Methods

Systematic scoping review design. Searched in PubMed and EMBASE from inception to 09-03-2016. References were screened and selected based on abstract and full text according to eligibility criteria. Full text articles were assessed for inclusion and summarized. The results are presented in three separate objectives and summarized for an overview of evidence.

Results

The search yielded 5,823 studies, of which 62 were included. Dental hand pieces were found to generate aerosols in the dental settings. Another 30 sources from human activities, interventions and daily cleaning performances in the hospital also generate aerosols. Fifty-five bacterial species, 45 fungi genera and ten viruses were identified in a hospital setting and 16 bacterial and 23 fungal species in the dental environment. Patients with certain risk factors had a higher chance to acquire Legionella in hospitals. Such infections can lead to irreversible septic shock and death. Only a few studies found that bio-aerosol generating procedures resulted in transmission of infectious diseases or allergic reactions.

Conclusion

Bio-aerosols are generated via multiple sources such as different interventions, instruments and human activity. Bio-aerosols compositions reported are heterogeneous in their microbiological composition dependent on the setting and methodology. Legionella species were found to be a bio-aerosol dependent hazard to elderly and patients with respiratory complaints. But all aerosols can be can be hazardous to both patients and healthcare workers.

Oral microbial ecology and the role of salivary immunoglobulin A

In the oral cavity, indigenous bacteria are often associated with two major oral diseases, caries and periodontal diseases. These diseases seem to appear following an imbalance in the oral resident microbiota, leading to the emergence of potentially pathogenic bacteria. To define the process involved in caries and periodontal diseases, it is necessary to understand the ecology of the oral cavity and to identify the factors responsible for the transition of the oral microbiota from a commensal to a pathogenic relationship with the host. The regulatory forces influencing the oral ecosystem can be divided into three major categories: host related, microbe related, and external factors. Among host factors, secretory immunoglobulin A (SIgA) constitutes the main specific immune defense mechanism in saliva and may play an important role in the homeostasis of the oral microbiota. Naturally occurring SIgA antibodies that are reactive against a variety of indigenous bacteria are detectable in saliva. These antibodies may control the oral microbiota by reducing the adherence of bacteria to the oral mucosa and teeth. It is thought that protection against bacterial etiologic agents of caries and periodontal diseases could be conferred by the induction of SIgA antibodies via the stimulation of the mucosal immune system. However, elucidation of the role of the SIgA immune system in controlling the oral indigenous microbiota is a prerequisite for the development of effective vaccines against these diseases. The role of SIgA antibodies in the acquisition and the regulation of the indigenous microbiota is still controversial. Our review discusses the importance of SIgA among the multiple factors that control the oral microbiota. It describes the oral ecosystems, the principal factors that may control the oral microbiota, a basic knowledge of the secretory immune system, the biological functions of SIgA, and, finally, experiments related to the role of SIgA in oral microbial ecology.

Detection of high-risk groups and individuals for periodontal diseases: laboratory markers from analysis of saliva

The use of saliva as a source of components that may identify subjects at risk of developing destructive periodontitis, or provide markers of disease potential or activity, has been reviewed. It was concluded that bacteria, their constituents or products are unlikely to be rewarding and that host-derived salivary factors such as enzymes cannot identify risk, as deficiency states for these do not exist. Secretory IgA, plasma IgA and IgG isotype levels and specific antibodies may be associated with risk, but probably only if levels fall below those which are protective or a specific antibody response is absent. More work is needed to distinguish between monomeric and dimeric IgA antibodies and to identify IgG antibodies in longitudinal clinical studies. In general, although saliva may prove to be useful as a source of indicators of current disease activity or as a means of assessing responses to treatment, it is unlikely to provide evidence for the existence of risk factors.

Crevicular and salivary fibronectin before and after gingivitis treatment

The aims of this study were to assess crevicular fibronectin concentrations before and after conventional gingivitis treatment and to determine whether fibronectin concentration in whole saliva would be affected concomitantly. 10 subjects with generalized gingivitis were selected. Examinations were made before and after treatment and included measurements of clinical parameters as well as collection of samples of unstimulated saliva, stimulated saliva and crevicular material. The concentration of fibronectin was studied by an ELISA assay. Fibronectin was found in gingival crevices and in unstimulated as well as paraffin-stimulated whole saliva in pre- and post-treatment samples. There were no statistically significant differences between pre- and post-treatment concentrations of fibronectin, whether expressed as micrograms fibronectin/micrograms protein or as micrograms fibronectin/ml saliva.