Interferon-gamma inducible protein 16 and type I interferon receptors expression in experimental apical periodontitis induced in wild-type mice.

AIM: The aim of this study was to evaluate the IFI16 and IFN-α/ß receptors expression during the genesis and development of experimental apical periodontitis (AP) in mice teeth. METHODOLOGY: Apical periodontitis was induced in the lower first molars of 40 C57BL/6 mice. They were divided according to the experimental periods 2, 7, 14, 21 and 42 days (n = 8 per group). Five animals were used as a control group (without AP). Specimens were submitted to histological processing for description of the inflammatory process, immunostaining for the presence/absence and localization of IFI16 and IFN-α/ß receptors (qualitative and semi-quantitative analysis) and tartrate-resistant acid phosphatase (TRAP) histoenzimology. RESULTS: The results showed a gradual development of AP over the experimental times. The expression of IFI16 was noticeably more exacerbated in the experimental early period (day 2) whilst the lowest expression was observed in the control group (p = .02). For IFN-α/ß receptors, a higher intensity staining was observed 42 days after AP induction, that was statistically different from the control group (p = .02). In addition, the number of TRAP-positive cells was higher on the later periods (days 21 and 42; p < .001). CONCLUSION: IFI16 protein expression was highest during the early periods after AP induction in mice teeth, whilst IFN-α/ß receptor expression was highest after AP became established.

Direct pulp capping with a self-etching adhesive system: histopathologic evaluation in dogs' teeth.

OBJECTIVE: This study evaluated histopathologically the response of pulp and periradicular tissues after pulp capping with an all-in-one self-etching adhesive system in dogs' teeth. STUDY DESIGN: Forty teeth of 4 dogs were assigned to 3 groups according to the pulp capping material: G1 (n = 20): self-etching adhesive system; G2 (n = 10): Ca(OH)(2); G3 (n = 10): zinc oxide-eugenol. The animals were killed 7 and 70 days after pulp capping. The pieces containing the pulp-capped teeth were removed and processed for histologic analysis. RESULTS: At 7 days, no dentin bridge formation was observed; G1 and G3 exhibited inflammatory pulpal alterations, whereas G2 presented only mild inflammatory infiltrate in the pulp tissue adjacent to the capping material, the remainder being intact. At 70 days, no specimen in G1 or G3 presented dentin bridge formation. The remaining pulp tissue exhibited severe inflammatory alterations and areas of necrosis. In G2, all specimens showed dentin bridge formation and absence of inflammation and mineralized tissue resorption. No bacteria were identified using Brown and Brenn staining techniques in all 3 groups at any observation period. CONCLUSION: According to the conditions of this study, direct pulp capping with the self-etching adhesive system did not allow pulp tissue repair and failed histopathologically in 100% of the cases.

Aggressive periodontitis associated with Papillon-Lefèvre syndrome: report of a 14-year follow-up.

This case report describes the periodontal management, therapeutic approach, and 14-year follow-up of a patient diagnosed with Papillon-Lefevre syndrome (PLS). A female child, diagnosed with PLS-associated periodontitis at the age of 9 years and 11 months, presented with hyperkeratosis of the palms and soles, as well as generalized aggressive periodontitis. The dental treatment comprised standard periodontal debridement, scaling and root planing, instructions on oral hygiene, restorations, extraction of hopelessly affected teeth and a therapeutic use of antibiotics. The concomitant supportive periodontal therapy and antibiotic coverage could not stop the loss of periodontal attachment and destruction of the alveolar bone. Four years after treatment was initiated, the last remaining teeth were extracted and complete dentures were constructed. The dentures have been periodically replaced and the patient continues to return for follow-up once a year. The combination of intensive periodontal treatment and antibiotic regimen only temporarily delayed periodontal disease progression and did not prevent loss of both primary and permanent teeth. The outcome of this long-term follow-up case report shows that management of PLS-associated periodontitis is further complicated when the patient is first seen in the mixed dentition stage or later. In these situations, the chances of controlling the progression of periodontal breakdown and minimizing tooth loss are greatly reduced.