The role of epidemiology in the study of periodontal diseases

Are Cementoblasts a Subpopulation of Osteoblasts or a Unique Phenotype?

Experimental studies have shown a great potential for periodontal regeneration. The limitations of periodontal regeneration largely depend on the regenerative potential at the root surface. Cellular intrinsic fiber cementum (CIFC), so-called bone-like tissue, may form instead of the desired acellular extrinsic fiber cementum (AEFC), and the interfacial tissue bonding may be weak. The periodontal ligament harbors progenitor cells that can differentiate into periodontal ligament fibroblasts, osteoblasts, and cementoblasts, but their precise location is unknown. It is also not known whether osteoblasts and cementoblasts arise from a common precursor cell line, or whether distinct precursor cell lines exist. Thus, there is limited knowledge about how cell diversity evolves in the space between the developing root and the alveolar bone. This review supports the hypothesis that AEFC is a unique tissue, while CIFC and bone share some similarities. Morphologically, functionally, and biochemically, however, CIFC is distinctly different from any bone type. There are several lines of evidence to propose that cementoblasts that produce both AEFC and CIFC are unique phenotypes that are unrelated to osteoblasts. Cementum attachment protein appears to be cementum-specific, and the expression of two proteoglycans, fibromodulin and lumican, appears to be stronger in CIFC than in bone. A theory is presented that may help explain how cell diversity evolves in the periodontal ligament. It proposes that Hertwig’s epithelial root sheath and cells derived from it play an essential role in the development and maintenance of the periodontium. The role of enamel matrix proteins in cementoblast and osteoblast differentiation and their potential use for tissue engineering are discussed.

Trends of periodontal conditions in two different randomly selected Swiss (Bernese) cohorts 25 years apart

AIM

To assess the periodontal conditions of two randomly selected Swiss cohorts 25 years apart.

MATERIAL AND METHODS

Standardized examinations were performed to assess the periodontal conditions of two randomly selected populations of the Canton of Bern; oral cleanliness was evaluated using the plaque index (PlI) and the retention index (RI). Gingival health was scored according to the gingival index (GI). Periodontal conditions were evaluated by pocket probing depth (PPD) and loss of attachment (LA).

RESULTS

At the first examination in 1985, 206 out of 350 subjects were evaluated, while in the second examination in 2010, 134 out of 490 subjects attended the examinations. In 1985, subjects showed a mean PlI of 1.16, and 0.77 in 2010. RI was 0.81 and 0.36 in 1985 and 2010 respectively. Mean GI was 1.34 and 0.6. The mean proportion of PPD ≤3 mm was 72% in 1985 and 97.3% in 2010. PPD ≥ 6 mm affected 2.0% in 1985 and 0.3% in 2010. In 1985, subjects had an average of 20.7 teeth, while in 2010, the average was 24.6. In 1985, 7.3% of the subjects were edentulous, while in 2010, 4.5% had no teeth.

CONCLUSIONS

Trends to improvements resulting in more teeth in function and better periodontal conditions were recognized.

A brief history of national surveillance efforts for periodontal disease in the United States

National efforts directed toward improving our understanding of the epidemiology of periodontal disease began nearly a half century ago following the development of Russell's periodontal index (PI). United States Public Health Service agencies began national surveillance activities for periodontal disease with the first National Health Examination Survey in 1960 to 1962, and this continued periodically through 2004 in the National Health and Nutrition Examination Survey (NHANES). Periodontal disease status was assessed by using the PI in the earlier national health surveys, but beginning in the 1980s, direct measures for clinical attachment loss were made in national health surveys and continued through 2004 in NHANES. This article provides a general history of the development and implementation of national surveillance efforts for periodontal disease from the mid-1950s to 2005. It also provides brief background information on the factors that have influenced these national surveillance efforts.

Antibacterial activity of moxifloxacin against periodontal anaerobic pathogens involved in systemic infections

The in vitro activity of moxifloxacin was compared with that of penicillin G, amoxycillin/clavulanate, cefoxitin, erythromycin, clindamycin and metronidazole against 158 isolates associated with periodontal infections. MIC(50)/MIC(90) values of moxifloxacin were respectively 0.06/0.5 mg/l for Porphyromonas gingivalis (35), for Prevotella spp. (28) and Actinomyces spp. (35), 0.12/0.25 mg/l for Fusobacterium nucleatum (20) and 0.06/0.12 mg/l for Peptostreptococcus spp. (30). The minimum inhibitory concentration (MIC) range of moxifloxacin for Bacteroides forsythus (6) and Campylobacter rectus (4) was 0.06-0.12 mg/l. The minimum bactericidal concentrations were equal to or 2-4 times the MIC values. Moxifloxacin produced a bactericidal effect at 8 h. Our results show that moxifloxacin has good antibacterial activity against periodontal pathogens comparable with that of cefoxitin and amoxycillin/clavulanate, and better than that of clindamycin, metronidazole and penicillin.

The periodontal disease problem. A comparison between industrialised and developing countries

There is no reason to believe that periodontal diseases in industrialised and developing countries are in principle different. That is, not in the sense that the problem is caused by a different set of periodontal diseases, with different micro-organisms and a different natural history, needing a different approach towards prevention and treatment. Indeed, from a public health perspective the relative similarities in periodontal conditions around the world are far more striking than the differences. The view that periodontal diseases are a much more prevalent and a severe problem in the developing countries seems to be true only in terms of poorer oral hygiene and considerably greater calculus retention, already at a young age, but not so clear for periodontal destruction in adults.

Epidemiology of periodontal disease among older adults: a review

Although many epidemiological studies have been conducted concerning periodontal disease, the majority were not included in this review because of deficiencies in the measures used. Although it is increasingly common for studies in this field to measure periodontal disease using clinical attachment level, attachment loss or bone loss, the evidence pertaining to prevalence, incidence and risk in older adult populations is limited. Although it is the best indicator to date, characterizing periodontal disease by means of attachment loss has some limitations. Prevalence and incidence rates may vary according to the number of teeth and sites probed and bias and case misclassification may occur because of the healthy survivor effect. Moreover, prevalence data that document lifetime disease experience are of little use in planning for periodontal treatment needs. Problems with sampling or subject selection and idiosyncratic ways of reporting data also limit the quality of the evidence currently available. In order to standardize the collection of data on loss of attachment and to measure it as accurately as possible, Papapanou (63) recommends that studies use full-mouth periodontal examinations and the assessment of clinical attachment level at four sites on each remaining tooth. Given the inconsistencies in and problems with the methods used in the studies reviewed above, only broad conclusions can be drawn concerning periodontal disease in older adults. These confirm the conclusions reached in other reviews of the literature. While moderate levels of attachment loss are to be found in a high percentage of middle-aged and elderly subjects, severe loss is confined to a minority, albeit a substantial one. Severe loss is evident in only a few sites and, in general, affects only a small proportion of sites examined. Nevertheless, approximately one-fifth of older individuals have experienced more generalized severe loss; the rate is much higher in the oldest subjects and subjects from minority groups. Although not universal, severe disease is common in some older populations and some population subgroups. Studies using common approaches are needed to fully elucidate the extent to which disease experience varies across different populations. Similar conclusions can be drawn from prevalence studies measuring bone loss. These show that a minority of subjects accounted for most sites with advanced loss. Studies of incidence suggest that 50-75% of older adults experience additional loss of attachment of 2 or 3 mm or more at a minimum of one site over relatively short periods of time. Rates fall dramatically when more stringent case definitions are used. Moreover, relatively few sites examined show evidence of additional loss so that, although rates are high, extent and severity are low. More detailed analyses of incidence data, although few, indicate that new lesions are more common than progressing lesions, and the pattern of loss tends to support an episodic model of periodontal disease progression.