Microbial etiological agents of destructive periodontal diseases

The authors have taken the liberty of presenting this manuscript in two parts. The first is a brief primer on microbial ecology, because, although the importance of microbial ecology in periodontal diseases is widely recognized, most of us do not know precisely what is meant by the term. The second section is a rather extensive overview of current studies of oral microbial ecology based almost entirely on recent in vivo studies.

https://laurieximenez.files.wordpress.com/2011/02/ref-2_socransky-2005_p2000.pdf

Periodontal microbial ecology.

Background Authors were assigned the task to develop case definitions for periodontitis in the context of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions. The aim of this manuscript is to review evidence and rationale for a revision of the current classification, to provide a framework for case definition that fully implicates state-of-the-art knowledge and can be adapted as new evidence emerges, and to suggest a case definition system that can be implemented in clinical practice, research and epidemiologic surveillance. Methods Evidence gathered in four commissioned reviews was analyzed and interpreted with special emphasis to changes with regards to the understanding available prior to the 1999 classification. Authors analyzed case definition systems employed for a variety of chronic diseases and identified key criteria for a classification/case definition of periodontitis. Results The manuscript discusses the merits of a periodontitis case definition system based on Staging and Grading and proposes a case definition framework. Stage I to IV of periodontitis is defined based on severity (primarily periodontal breakdown with reference to root length and periodontitis-associated tooth loss), complexity of management (pocket depth, infrabony defects, furcation involvement, tooth hypermobility, masticatory dysfunction) and additionally described as extent (localized or generalized). Grade of periodontitis is estimated with direct or indirect evidence of progression rate in three categories: slow, moderate and rapid progression (Grade A-C). Risk factor analysis is used as grade modifier. Conclusions The paper describes a simple matrix based on stage and grade to appropriately define periodontitis in an individual patient. The proposed case definition extends beyond description based on severity to include characterization of biological features of the disease and represents a first step towards adoption of precision medicine concepts to the management of periodontitis. It also provides the necessary framework for introduction of biomarkers in diagnosis and prognosis.

https://onlinelibrary.wiley.com/doi/epdf/10.1111/jcpe.12945

Staging and grading of periodontitis: Framework and proposal of a new classification and case definition.

We aimed to consolidate all epidemiologic data about severe periodontitis (SP) and, subsequently, to generate internally consistent prevalence and incidence estimates for all countries, 20 age groups, and both sexes for 1990 and 2010. The systematic search of the literature yielded 6,394 unique citations. After screening titles and abstracts, we excluded 5,881 citations as clearly not relevant to this systematic review, leaving 513 for full-text review. A further 441 publications were excluded following the validity assessment. A total of 72 studies, including 291,170 individuals aged 15 yr or older in 37 countries, were included in the metaregression based on modeling resources of the Global Burden of Disease 2010 Study. SP was the sixth-most prevalent condition in the world. Between 1990 and 2010, the global age-standardized prevalence of SP was static at 11.2% (95% uncertainty interval: 10.4%-11.9% in 1990 and 10.5%-12.0% in 2010). The age-standardized incidence of SP in 2010 was 701 cases per 100,000 person-years (95% uncertainty interval: 599-823), a nonsignificant increase from the 1990 incidence of SP. Prevalence increased gradually with age, showing a steep increase between the third and fourth decades of life that was driven by a peak in incidence at around 38 yr of age. There were considerable variations in prevalence and incidence between regions and countries. Policy makers need to be aware of a predictable increasing burden of SP due to the growing world population associated with an increasing life expectancy and a significant decrease in the prevalence of total tooth loss throughout the world from 1990 to 2010.

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Global Burden of Severe Periodontitis in 1990-2010 A Systematic Review and Meta-regression

Many definitions of periodontitis have been used in the literature for population-based studies, but there is no accepted standard. In early epidemiologic studies, the two major periodontal diseases, gingivitis and periodontitis, were combined and considered to be a continuum. National United States surveys were conducted in 1960 to 1962, 1971 to 1974, 1981, 1985 to 1986, 1988 to 1994, and 1999 to 2000. The case definitions and protocols used in the six national surveys reflect a continuing evolution and improvement over time. Generally, the clinical diagnosis of periodontitis is based on measures of probing depth (PD), clinical attachment level (CAL), the radiographic pattern and extent of alveolar bone loss, gingival inflammation measured as bleeding on probing, or a combination of these measures. Several other patient characteristics are considered, and several factors, such as age, can affect measurements of PD and CAL. Accuracy and reproducibility of measurements of PD and CAL are important because case definitions for periodontitis are based largely on either or both measurements, and relatively small changes in these values can result in large changes in disease prevalence. The classification currently accepted by the American Academy of Periodontology (AAP) was devised by the 1999 International Workshop for a Classification of Periodontal Diseases and Conditions. However, in 2003 the Centers for Disease Control and Prevention and the AAP appointed a working group to develop further standardized clinical case definitions for population-based studies of periodontitis. This classification defines severe periodontitis and moderate periodontitis in terms of PD and CAL to enhance case definitions and further demonstrates the importance of thresholds of PD and CAL and the number of affected sites when determining prevalence.

Case Definitions for Use in Population-Based Surveillance of Periodontitis

Current scoring systems for dental caries do not consider the dynamic nature of the disease. The aims of the present study were to describe a new set of clinical caries diagnostic criteria which differentiate between active and inactive caries lesions at both the cavitated and non-cavitated levels and to evaluate the reliability of this criteria system in a population with high caries experience. Ten diagnostic codes were defined: 0 = sound; 1 = active (intact); 2 = active (surface discontinuity); 3 = active (cavity); 4 = inactive (intact); 5 = inactive (surface discontinuity); 6 = inactive (cavity); 7 = filling; 8 = filling with active caries; 9 = filling with inactive caries. Distinction between active and inactive caries lesions was made on the basis of a combination of visual and tactile criteria. The inter- and intra-examiner reliability was assessed through repeated examinations of 50 children by 2 recorders over a period of 3 years. The percentage agreement of caries diagnoses varied between 94.2 and 96.2%. The kappa values ranged between 0.74 and 0.85 for intra-examiner examinations and between 0.78 and 0.80 for inter-examiner examinations; 81.6% of all misclassifications involved non-cavitated caries lesions. Disagreement between sound surfaces and non-cavitated active or non-cavitated inactive lesions (31.3 and 31.2%, respectively) was more common than disagreement between non-cavitated active and non-cavitated inactive lesions (10. 6%). The probability of reconfirming a sound, non-cavitated active or non-cavitated inactive caries lesion - given that the surface was diagnosed as either sound, non-cavitated active or non-cavitated inactive at the first examination - was 98.0, 68.7 and 72.5%, respectively. The results show that the use of a new set of clinical caries diagnostic criteria based on activity assessment can be performed with a high reliability, even when non-cavitated diagnoses are included in the criteria system.

Reliability of a new caries diagnostic system differentiating between active and inactive caries lesions.

Any use of fluorides, whether systemic or topical, in caries prevention and treatment in children results in ingestion and absorption of fluoride into the blood circulation. The mineralization of teeth under formation may be affected so that dental fluorosis may occur. Dental fluorosis reflects an increasing porosity of the surface and subsurface enamel, causing the enamel to appear opaque. The clinical features represent a continuum of changes ranging from fine white opaque lines running across the tooth on all parts of the enamel to entirely chalky white teeth. In the latter cases, the enamel may be so porous (or hypomineralized) that the outer enamel breaks apart posteruptively and the exposed porous subsurface enamel becomes discolored. These changes can be classified clinically by the TF index to reflect, in an ordinal scale, the histopathological changes associated with dental fluorosis. Compared with Dean's and the TSIF index, we consider the TF index to be more precise. Recent studies on human enamel representing the entire spectrum of dental fluorosis have demonstrated a clear association between increasing TF score and increasing fluoride content of the enamel. So far, no useful data on dose (expressed in mg fluoride/kg b.w.)-response (dental fluorosis) relationships are available. In this paper, we have, therefore, re-evaluated the original data by Dean et al. (1941, 1942), Richards et al. (1967), and Butler et al. (1985) from the USA, by applying the equation of Galagan and Vermillion (1957) which permits the calculation of water intake as a function of temperature.(ABSTRACT TRUNCATED AT 250 WORDS)

The nature and mechanisms of dental fluorosis in man.

This study describes the cross-sectional findings on dental plaque, calculus, gingivitis, loss of attachment, periodontal pockets and tooth loss in a population of adult Tanzanians aged 30–30 years. In all age groups more than 90% of all tooth surfaces exhibited plaque and 50–50% exhibited calculus deposits. Both plaque and calculus deposits were more extensive in the older age groups whereas gingival bleeding affected 30–30% of the surfaces in all age groups. Less than 35% of all surfaces exhibited a loss of attachment ≥4 mm and less than 10% had a loss of attachment exceeding 6 mm. Loss of attachment was accompanied by recession of the marginal gingiva and pockets deeper than 3 mm were present on less than 10% of all surfaces. The mean number of teeth present ranged from 23.9 in the oldest to 29.5 in the youngest age group. An interesting finding was that relatively few individuals accounted for most of the loss of attachment and periodontal pockets found in the study. Therefore, in future epidemiologic studies more emphasis should be put on the identification of these particularly susceptible subpopulations.

Oral hygiene, gingivitis and periodontal breakdown in adult Tanzanians.

It is now well-established that a linear relationship exists between fluoride dose and enamel fluorosis in human populations. With increasing severity, the subsurface enamel all along the tooth becomes increasingly porous (hypomineralized), and the lesion extends toward the inner enamel. In dentin, hypomineralization results in an enhancement of the incremental lines. After eruption, the more severe forms are subject to extensive mechanical breakdown of the surface. The continuum of fluoride-induced changes can best be classified by the TF index, which reflects, on an ordinal scale, the histopathological features and increases in enamel fluoride concentrations. Human and animal studies have shown that it is possible to develop dental fluorosis by exposure during enamel maturation alone. It is less apparent whether an effect of fluoride on the stage of enamel matrix secretion, alone, is able to produce changes in enamel similar to those described as dental fluorosis in man. The clinical concept of post-eruptive maturation of erupting sound human enamel, resulting in fluoride uptake, most likely reflects subclinical caries. Incorporation of fluoride into enamel is principally possible only as a result of concomitant enamel dissolution (caries lesion development). At higher fluoride concentrations, calcium-fluoride-like material may form, although the formation, identification, and dissolution of this compound are far from resolved. It is concluded that dental fluorosis is a sensitive way of recording past fluoride exposure because, so far, no other agent or condition in man is known to create changes within the dentition similar to those induced by fluoride. Since the predominant cariostatic effect of fluoride is not due to its uptake by the enamel during tooth development, it is possible to obtain extensive caries reductions without a concomitant risk of dental fluorosis.

Dental Tissue Effects of Fluoride

This study comprised 1131 persons who constitute a stratified random sample of the entire population aged 15-65 years in Machakos District, Kenya. Each person was examined for tooth mobility, plaque, calculus, gingival bleeding, loss of attachment and pocket depth on the mesial, buccal, distal and lingual surface of each tooth. The oral hygiene was poor with plaque on 75-95% and calculus on 10-85% of the surfaces depending on age. Irrespective of age, pockets greater than or equal to 4 mm was seen on less than 20% of the surfaces, whereas 10-85% of the surfaces had loss of attachment greater than or equal to 1 mm. The proportion of surfaces per individual with loss of attachment greater than or equal to 4 mm or greater than or equal to 7 mm, and pocket depths greater than or equal to 4 mm or greater than or equal to 7 mm, respectively, showed a pronounced skewed distribution, indicating that in each age group, a subfraction of individuals is responsible for a substantial proportion of the total periodontal breakdown. The individual teeth within the dentition also showed a marked variation in the severity of periodontal breakdown. Our findings provide additional evidence that destructive periodontal disease should not be perceived as an inevitable consequence of gingivitis which ultimately leads to considerable tooth loss. A more specific characterization of the features of periodontal breakdown in those individuals who seem particularly susceptible is therefore warranted.

Vibeke Baelum

Papers

Reliability of a new caries diagnostic system differentiating between active and inactive caries lesions.

The nature and mechanisms of dental fluorosis in man.

Oral hygiene, gingivitis and periodontal breakdown in adult Tanzanians.

Dental Tissue Effects of Fluoride

Periodontal diseases in adult Kenyans