Subgingival microbiota from Cebus apella (capuchin monkey) with different periodontal conditions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Accuracy of zoomed digital image in the detection of periodontal bone defect: in vitro study

Objectives: (1) To evaluate the intraobserver agreement related to image interpretation and (2) to compare the accuracy of 100%, 200% and 400% zoomed digital images in the detection of simulated periodontal bone defects.Methods: Periodontal bone defects were created in 60 pig hemi-mandibles with slow-speed burs 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm and 3.0 mm in diameter. 180 standardized digital radiographs were made using Schick sensor and evaluated at 100%, 200% and 400% zooming. The intraobserver agreement was estimated by Kappa statistic (kappa). For the evaluation of diagnostic accuracy receiver operating characteristic (ROC) analysis was performed followed by chi-square test to compare the areas under ROC curves according to each level of zooming.Results: For 100%, 200% and 400% zooming the intraobserver agreement was moderate (kappa = 0.48, kappa = 0.54 and kappa = 0.43, respectively) and there were similar performances in the discrimination capacity, with ROC areas of 0.8611 (95% CI: 0.7660-0.9562), 0.8600 (95% CI: 0.7659-0.9540), and 0.8368 (95% CI: 0.7346-0.9390), respectively, with no statistical significant differences (chi(2)-test; P = 0.8440).Conclusions: A moderate intraobserver agreement was observed in the classification of periodontal bone defects and the 100%, 200% and 400% zoomed digital images presented similar performances in the detection of periodontal bone defects.

Actinobacillus actinomycetemcomitans lipopolysaccharide induces interleukin-6 expression through multiple mitogen-activated protein kinase pathways in periodontal ligament fibroblasts

Actinobacillus actinomycetemcomitans plays a major role in the pathogenesis of aggressive periodontitis. Lipopolysaccharide (LPS) derived from A. actinomycetemcomitans is a key factor in inflammatory cytokine generation within periodontal tissues. In this study, we identify major mitogen-activated protein kinase (MAPK) signaling pathways induced by A. actinomycetemcomitans LPS, Escherichia coli LPS and interleukin-1 beta (IL-1 beta) in a murine periodontal ligament (mPDL) fibroblast cell line. Immunoblot analysis was used to assess the phosphorylated forms of p38, extracellular-regulated kinase (ERK) and c-jun N-terminal kinase (JNK) MAPK following stimulation with A. actinomycetemcomitans LPS, E. coli LPS and IL-1 beta. IL-6 mRNA induction was detected via reverse transcription-polymerase chain reaction, while protein levels were quantified via enzyme-linked immunosorbent assays (ELISA). We utilized biochemical inhibitors of p38, ERK and JNK MAPK to identify the MAPK signaling pathways needed for IL-6 expression. Additional use of stable mPDL cell lines containing dominant negative mutant constructs of MAPK kinase-3 and -6 (MKK-3/6) and p38 null mutant mouse embryonic fibroblast (MEF) cells were used to substantiate the biochemical inhibitor data. Blocking p38 MAPK with SB203580 reduced the induction of IL-6 mRNA by A. actinomycetemcomitans LPS, E. coli LPS and IL-1 beta by > 70%, > 95% and similar to 60%, respectively. IL-6 ELISA indicated that blocking p38 MAPK reduced the IL-6 protein levels induced by A. actinomycetemcomitans LPS, E. coli LPS and IL-1 beta by similar to 60%, similar to 50% and similar to 70%, respectively. All MAPK inhibitors significantly reduced the IL-6 protein levels induced by A. actinomycetemcomitans LPS, E. coli LPS and IL-1 beta whereas only p38 inhibitors consistently reduced the A. actinomycetemcomitans LPS, E. coli LPS and IL-1 beta induction of IL-6 mRNA steady-state levels. The contribution of p38 MAPK LPS-induced IL-6 expression was confirmed using MKK-3/6 dominant negative stable mPDL cell lines. Wild-type and p38 alpha(-/-) MEF cells provided additional evidence to support the role of p38 alpha MAPK in A. actinomycetemcomitans LPS-stimulated IL-6. Our results indicate that induction of IL-6 by E. coli LPS, IL-1 beta and A. actinomycetemcomitans LPS requires signaling through MKK-3-p38 alpha ERK, JNK and p38 MAPK in mPDL cells.

Lethal photosensitization and guided bone regeneration in treatment of peri-implantitis: an experimental study in dogs

The purpose of this study was to evaluate the effect of lethal photosensitization and guided bone regeneration (GBR) on the treatment of ligature-induced peri-implantitis in different implant surfaces. The treatment outcome was evaluated by clinical and histometric methods. A total of 40 dental implants with four different surface coatings (10 commercially pure titanium surface (cpTi); 10 titanium plasma-sprayed (TPS); 10 acid-etched surface; 10 surface-oxide sandblasted) were inserted into five mongrel dogs. After 3 months, the animals with ligature-induced peri-implantitis were subjected to surgical treatment using a split-mouth design. The controls were treated by debridment and GBR, while the test side received an additional therapy with photosensitization, using a GaAlAs diode laser, with a wavelength of 830 nm and a power output of 50 mW for 80 s (4 J/cm(2)), and sensitized toluidine blue O (100 mu g/ml). The animals were sacrificed 5 months after therapy. The control sites presented an earlier exposition of the membranes on all coating surfaces, while the test group presented a higher bone height gain. Re-osseointegration ranged between 41.9% for the cpTi surface and 31.19% for the TPS surface in the test sites; however differences were not achieved between the surfaces. The lethal photosensitization associated with GBR allowed for better re-osseointegration at the area adjacent to the peri-implant defect regardless of the implant surface.

The influence of loss of bone mass on induced periodontal disease: A radiographic and densitometric study of female rats

Background: Changes in mineral density in the mandibular and femoral bones (BMD) after estrogen deficiency caused by ovariectomy (OVX) and the influence of these changes on induced periodontal disease were evaluated in female rats.Methods: Forty-eight female Holtzman rats (90 days old) were randomly divided into five groups: 0: control (N = 9); 1: SHAM without induced periodontal disease (N = 11); 2: SHAM with induced disease (N = 10); 3: OVX without induced disease (N = 9); and 4: OVX with induced disease (N = 9). In groups 2 and 4, the first lower molars were tied with ligatures for 30 days 120 days after surgery. After 5 months the animals were sacrificed to measure global mineral density (BMD) and that of the sub-regions of the mandible and femur by dual energy x-ray absorptiometry (DXA). The extent of vertical bone loss was evaluated with digital radiography by measuring the distance from the bone crest to the cemento-enamel junction at the mesial of the first lower molar.Results: Results of the femur (Kruskal-Wallis test) showed a significant difference (P < 0.001) between the groups SHAM and OVX in bone density values for all regions. Comparison between the groups in relation to the BMD of the mandible, both in the sub-regions and global revealed no differences (P < 0.05). The vertical bone loss measured for the groups with induced disease was similar (P= 0.713).Conclusions: Differences between the groups were found in the bone mineral density BMD of the femur but not of the mandible. OVX had no influence on induced periodontal disease.

Combined periodontal, orthodontic, and restorative treatment of pathologic migration of anterior teeth: A case report

Pathologic tooth migration related to periodontal disease is a common chief complaint of periodontal patients. This paper describes the treatment of a case of severe periodontal disease and disfiguring pathologic migration of maxillary central incisors, which required a multidisciplinary approach. After conventional pert. odontal treatment was performed, the anterior diastema was closed using a combination of orthodontic therapy and restorative treatment. A 6-month follow-up examination of this case revealed resolution of the anterior pathologic migration, with gains in clinical attachment levels and a successful esthetic and functional final result.

Curcumin modulates the immune response associated with LPS-induced periodontal disease in rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Potent anti-inflammatory effects of systemically administered curcumin modulate periodontal disease in vivo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Bone regeneration after demineralized bone matrix and castor oil (Ricinus communis) polyurethane implantation

Innocuous biocompatible materials have been searched to repair or reconstruct bone defects. Their goal is to restore the function of live or dead tissues. This study compared connective tissue and bone reaction when exposed to demineralized bovine bone matrix and a polyurethane resin derived from castor bean (Ricinus communis). Forty-five rats were assigned to 3 groups of 15 animals (control, bovine bone and polyurethane). A cylindrical defect was created on mandible base and filled with bovine bone matrix and the polyurethane. Control group received no treatment. Analyses were performed after 15, 45 and 60 days (5 animals each). Histological analysis revealed connective tissue tolerance to bovine bone with local inflammatory response similar to that of the control group. After 15 days, all groups demonstrated similar outcomes, with mild inflammatory reaction, probably due to the surgical procedure rather than to the material. In the polymer group, after 60 days, scarce multinucleated cells could still be observed. In general, all groups showed good stability and osteogenic connective tissue with blood vessels into the surgical area. The results suggest biocompatibility of both materials, seen by their integration into rat mandible. Moreover, the polyurethane seems to be an alternative in bone reconstruction and it is an inexhaustible source of biomaterial.