Periodontitis is an infectious disease, where putative periodontopathogens trigger chronic inflammatory and immune responses against periodontal structures, in which an unbalanced host response is also determinant to the disease outcome. It is reasonable to assume that patient susceptibility to periodontal tissue destruction could be determined by the balance between the response against periodontopathogens and regulatory mechanisms of these events mediated by suppressive T cells. In the present study, we identified and characterized natural regulatory T cells (Tregs) in the inflammatory infiltrate of human chronic periodontitis (CP) with emphasis on phenotypic analyses that were carried out to address the participation of Tregs in CP. Results showed that patients with CP presented increased frequency of T lymphocytes and CD4+CD25+ T cells in the inflammatory infiltrate of gingival tissues. These cells exhibited the phenotypic markers of Tregs such as forkhead box p3 (Foxp3), CTLA-4, glucocorticoid-inducible TNFR, CD103, and CD45RO and seemed to be attracted to the inflammation site by the chemokines CCL17 and CCL22, as their expression and its receptor CCR4 were increased in CP patients. Moreover, besides the increased detection of Foxp3 mRNA, diseased tissues presented high expression of the regulatory cytokines IL-10 and TGF-beta. In addition, the inflammatory infiltrate in CP biopsies was composed of CD25+Foxp3+ and CD25+TGF-beta+ cells, thus corroborating the hypothesis of the involvement of Tregs in the pathogenesis of CP. Finally, these results indicate that Tregs are found in the chronic lesions and must be involved in the modulation of local immune response in CP patients.
Periodontitis comprises a group of multifactorial diseases in which
periodontopathogens accumulate in dental plaque and trigger host chronic inflammatory
and immune responses against periodontal structures, which are determinant to the
disease outcome. Although unusual cases of non-inflammatory destructive periodontal
disease (NIDPD) are described, their pathogenesis remains unknown. A unique NIDPD
case was investigated by clinical, microbiological, immunological and genetic tools.
The patient, a non-smoking dental surgeon with excessive oral hygiene practice,
presented a generalized bone resorption and tooth mobility, but not gingival
inflammation or occlusion problems. No hematological, immunological or endocrine
alterations were found. No periodontopathogens (A. actinomycetemcomitans, P.
gingivalis, F. nucleatum and T. denticola) or viruses
(HCMV, EBV-1 and HSV-1) were detected, along with levels of IL-1β and TNF-α in GCF
compatible with healthy tissues. Conversely ALP, ACP and RANKL GCF levels were
similar to diseased periodontal sites. Genetic investigation demonstrated that the
patient carried some SNPs, as well HLA-DR4 (*0404) and HLA-B27 alleles, considered
risk factors for bone loss. Then, a less vigorous and diminished frequency of
toothbrushing was recommended to the patient, resulting in the arrest of alveolar
bone loss, associated with the return of ALP, ACP and RANKL in GCF to normality
levels. In conclusion, the unusual case presented here is compatible with the
previous description of NIDPD, and the results that a possible combination of
excessive force and frequency of mechanical stimulation with a potentially bone loss
prone genotype could result in the alveolar bone loss seen in NIDPD.
In the present investigation, a scanning electron microscopy analysis was performed to evaluate the effects of the topical application of ethylenediaminetetraacetic acid (EDTA) gel associated with Cetavlon (EDTAC) in removing the smear layer and exposing collagen fibers following root surface instrumentation. Twenty-eight teeth from adult humans, single rooted and scheduled for extraction due to periodontal reasons, were selected. Each tooth was submitted to manual (scaling and root planing) instrumentation alone or combined with ultrasonic instruments, with or without etching using a 24% EDTAC gel. Following extraction, specimens were processed and examined under a scanning electron microscope. A comparative morphological semi-quantitative analysis was performed; the intensity of the smear layer and the decalcification of cementum and dentinal surfaces were graded in 12 sets using an arbitrary scale ranging from 1 (area covered by a smear layer) to 4 (no smear layer). Root debridement with hand instruments alone or combined with ultrasonic instruments resulted in a similar smear layer covering the root surfaces. The smear layer was successfully removed from the surfaces treated with EDTAC, which exhibited numerous exposed dentinal tubules and collagen fibers. This study supports the hypothesis that manual instrumentation alone or instrumentation combined with ultrasonic instrumentation is unable to remove the smear layer, whereas the subsequent topical application of EDTAC gel effectively removes the smear layer, uncovers dentinal openings and exposes collagen fibers.
Caros(as) leitores(as),
No período de 23 a 27 de maio acontece a 26ª Semana Odontológica da Universidade de Ribeirão Preto (SOURP), no Teatro Bassano Vaccarini e em outras instalações do campus Ribeirão da Universidade. O evento contará com palestras, cursos, hands-on e apresentações de trabalhos, além de Ações Sociais que são destinadas à toda comunidade interna e externa, como o Mutirão de Prevenção e Diagnóstico Precoce do Câncer de Boca, de Prevenção à Cárie Dental e de Diagnóstico, Prevenção e Orientações de Disfunções da ATM e Bruxismo.
Comissão Organizadora
26ª Semana Odontológica UNAERP - 26ª SOURP/ 2022
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