Mário Taba

Salivary Interleukin-6, Matrix Metalloproteinase-8, and Osteoprotegerin in Patients With Periodontitis and Diabetes

BACKGROUND Diabetes and periodontitis produce a protein discharge that can be reflected in saliva. This study evaluates the salivary concentrations of interleukin (IL)-6, matrix metalloproteinase (MMP)-8, and osteoprotegerin (OPG) in patients with periodontitis with type 2 diabetes. METHODS Whole saliva samples were obtained from 90 subjects who were divided into four groups: healthy (control; n = 22), untreated periodontitis (UPD; n = 24), diabetes mellitus (DM; n = 20), and UPD + DM (n = 24) groups. Clinical and metabolic data were recorded. Salivary IL-6, MMP-8, and OPG concentrations were determined by a standard enzyme-linked immunosorbent assay. RESULTS The UPD and UPD + DM groups exhibited higher salivary IL-6 than the control and DM groups (P <0.01). The salivary MMP-8 concentrations in all diseased groups (UPD, DM, and UPD + DM) were higher than in the control group (P <0.01). The salivary OPG concentrations in the DM group were higher than in the UPD and control groups (P <0.05). In the UPD + DM group, salivary IL-6 was correlated with glycated hemoglobin (HbA1c) levels (r = 0.60; P <0.05). The regression analysis indicated that the number of remaining teeth, clinical attachment level, and IL-6 might have influenced the HbA1c levels in patients with diabetes. CONCLUSIONS Salivary IL-6 concentrations were elevated in patients with periodontitis with or without diabetes. Salivary MMP-8 and OPG concentrations were elevated regardless of periodontal inflammation in patients with diabetes. Therefore, periodontitis and diabetes are conditions that may interfere with protein expression and should be considered when using saliva for diagnoses.

Gingival crevicular fluid levels of MMP‐8, MMP‐9, TIMP‐2, and MPO decrease after periodontal therapy

BACKGROUND This study aimed at comparing the levels of matrix metalloproteinase (MMP)-8, tissue Inhibitor of MMPs (TIMP)-1 and TIMP-2, Myeloperoxidase (MPO), and MMP-9 in the gingival crevicular fluid (GCF) of chronic periodontitis (CP) patients and controls at baseline and 3 months after non-surgical therapy. MATERIALS AND METHODS GCF was collected from one site of 15 control subjects and 27 CP patients. MMP-8, MMP-9, TIMP-1, and TIMP-2 were determined by Enzyme-linked immunoabsorbent assay; different forms of MMP-9, by gelatin zymography; and MPO, colorimetrically. RESULTS At baseline, higher levels of MMP-8, TIMP-2, MPO, and the 87 kDa-MMP-9 were found in patients compared with controls (p<0.001), and these molecules decreased after therapy (p<0.03). There were no differences between the groups with respect to the higher molecular forms of MMP-9 (180, 130, 92 kDa) or total MMP-9 at baseline. No differences were observed in TIMP-1 levels. In controls, decreased levels of TIMP-2 and the higher molecular forms of MMP-9 (180, 130, 92 kDa) were found 3 months after therapy compared with baseline (p<0.01). CONCLUSIONS Higher levels of MMP-8, TIMP-2, MPO, and 87 kDa MMP-9 were found in the GCF of patients compared with controls, and these markers decreased 3 months after periodontal therapy.

Determination of nitrite in saliva using microfluidic paper-based analytical devices.

Point-of-care platforms can provide fast responses, decrease the overall cost of the treatment, allow for in-home determinations with or without a trained specialist, and improve the success of the treatment. This is especially true for microfluidic paper-based analytical devices (μPAD), which can enable the development of highly efficient and versatile analytical tools with applications in a variety of biomedical fields. The objective of this work was the development of μPADs to identify and quantify levels of nitrite in saliva, which has been proposed as a potential marker of periodontitis. The devices were fabricated by wax printing and allowed the detection of nitrite by a colorimetric reaction based on a modified version of the Griess reaction. The presented modifications, along with the implementation of a paper-based platform, address many of the common drawbacks (color development, stability, etc.) associated with the Griess reaction and are supported by results related to the design, characterization, and application of the proposed devices. Under the optimized conditions, the proposed devices enable the determination of nitrite in the 10-1000 μmol L(-1) range with a limit of detection of 10 μmol L(-1) and a sensitivity of 47.5 AU [log (μmol L(-1))](-1). In order to demonstrate the potential impact of this technology in the healthcare industry, the devices were applied to the analysis of a series of real samples, covering the relevant clinical range.

Titanium membranes in prevention of alveolar collapse after tooth extraction.

Background and Purpose:The resorption of alveolar bone following tooth extraction results in a narrowing and shortening of the residual ridge, which leads to esthetic and restorative problems, and reduces the bone volume available for implant therapy. The aim of this study was to evaluate the prevention of alveolar collapse after tooth extraction, using titanium membrane (Frios Boneshield; DENTSPLY Friadent, Mannheim, Germany), associated (or not) with autologous bone graft. Materials and Methods:A total of 10 nonsmoking healthy subjects, ranging from 35 to 60 years old, were selected for this study. Each patient had a minimum of 2 uni-radicular periodontally hopeless teeth, which were scheduled for extraction. After the procedure, 2 titanium pins were fixed on the vestibular bone surfaces that were used as references for the initial measures (depth, width, and height) of the socket. Of the sockets,1 was randomly chosen to be filled with autologous bone graft (test) removed from superior maxillary tuber, and the other one did not receive the graft (control). A titanium membrane was adapted and fixed, covering the sockets, which remained for at least 10 weeks. After a 6-month healing, the final measures were performed. Results:There was exposure of the membrane in 5 of the 10 treated subjects. Average bone filling (±standard deviation) among the 10 subjects was 8.80 ± 2.93 mm (range 4-13) in the control group and 8.40 ± 3.35 mm (range 4-13) in the test group. Average bone loss in width in both group was 1.40 ± 1.97 mm (range −4-1) in the control group and 1.40 ± 0.98 mm (range −4-0) in the test group. There was no significant statistical difference between groups considering the evaluated standards. Conclusion:The use of titanium membrane, alone or in association with autogenous bone, favored the prevention of alveolar ridge after tooth extraction. This membrane seems to be a possible and safe alternative to other nonresorbable membranes when the prevention of alveolar ridge resorption is the objective.

Acellular dermal matrix and hydroxyapatite in prevention of ridge deformities after tooth extraction.

The aim of this study was to evaluate the role of acellular dermal matrix graft (ADMG) acting as a membrane, associated with a resorbable hydroxyapatite (RHA) in bone regeneration to prevent ridge deformities after tooth extraction. Fifteen patients who had at least 2 noncontiguous, uniradicular teeth indicated for extraction were selected. In group I, the extraction sockets were covered by ADMG alone; and in group II, the alveoli were filled with RHA before the placement of the ADMG. After 6 months, re-entry surgeries and biopsies were performed. Although ridge thickness had been preserved in both groups, the means were significantly greater (P <0.05) for group II when compared to group I (6,8 ± 1.26 and 5.53 ± 1.06). The histologic analysis showed small bone formation in some samples for group II, where the presence of a highly vascularized fibrous connective tissue surrounding the particles was a common finding. Based on the results, it can be concluded that the ADMG was able to preserve ridge thickness and that the additional use of RHA favored the preservation of the ridges along with an increase in the width of keratinized tissue.

Human alveolar bone cell proliferation, expression of osteoblastic phenotype, and matrix mineralization on porous titanium produced by powder metallurgy

OBJECTIVE This study aimed at investigating the influence of the porous titanium (Ti) structure on the osteogenic cell behaviour. MATERIALS AND METHODS Porous Ti discs were fabricated by the powder metallurgy process with the pore size typically between 50 and 400 microm and a porosity of 60%. Osteogenic cells obtained from human alveolar bone were cultured until subconfluence and subcultured on dense Ti (control) and porous Ti for periods of up to 17 days. RESULTS Cultures grown on porous Ti exhibited increased cell proliferation and total protein content, and lower levels of alkaline phosphatase (ALP) activity than on dense Ti. In general, gene expression of osteoblastic markers-runt-related transcription factor 2, collagen type I, alkaline phosphatase, bone morphogenetic protein-7, and osteocalcin was lower at day 7 and higher at day 17 in cultures grown on porous Ti compared with dense Ti, a finding consistent with the enhanced growth rate for such cultures. The amount of mineralized matrix was greater on porous Ti compared with the dense one. CONCLUSION These results indicate that the porous Ti is an appropriate substrate for osteogenic cell adhesion, proliferation, and production of a mineralized matrix. Because of the three-dimensional environment it provides, porous Ti should be considered an advantageous substrate for promoting desirable implant surface-bone interactions.

Antimicrobial Photodynamic Therapy as an Adjunct to Non-Surgical Treatment of Aggressive Periodontitis: A Split-Mouth Randomized Controlled Trial

BACKGROUND The management of aggressive periodontitis (AgP) represents a challenge for clinicians because there are no standardized protocols for an efficient control of the disease. This randomized controlled clinical trial evaluated the effects of repeated applications of antimicrobial photodynamic therapy (aPDT) adjunctive to scaling and root planing (SRP) in patients with AgP. METHODS Using a split-mouth design, 20 patients with generalized AgP were treated with aPDT + SRP (test group) or SRP only (control group). aPDT was applied at four periods. All patients were monitored for 90 days. Clinical, microbiologic, and immunologic parameters were statistically analyzed. RESULTS In deep periodontal pocket analysis (probing depth [PD] ≥ 7 mm at baseline), the test group presented a decrease in PD and a clinical attachment gain significantly higher than the control group at 90 days (P < 0.05). The test group also demonstrated significantly less periodontal pathogens of red and orange complexes and a lower interleukin-1β/interleukin-10 ratio than the control group (P < 0.05). CONCLUSION The application of four sessions of aPDT, adjunctive to SRP, promotes additional clinical, microbiologic, and immunologic benefits in the treatment of deep periodontal pockets in single-rooted teeth in patients with AgP.

AAV2/1-TNFR:Fc Gene Delivery Prevents Periodontal Disease Progression

Periodontal disease is a chronic inflammatory condition induced by tooth-associated microbial biofilms that induce a host immune response. Therapeutic control of progressive tissue destruction in high-risk patients is a significant challenge in therapy. Soluble protein delivery of antagonists to tumor necrosis factor-α (TNF-α) inhibits alveolar bone resorption due to periodontitis. However, protein therapy raises several concerns, such as recurrence of disease activity after treatment cessation and repeated dosing regimens. In this study, we used pseudotyped adeno-associated virus vector based on serotype 1 (AAV2/1) to deliver the TNF receptor-immunoglobulin Fc (TNFR:Fc) fusion gene to rats subjected to experimental Porphyromonas gingivalis (Pg)-lipopolysaccharide (LPS)-mediated bone loss. Animals received Pg-LPS delivered to the gingivae thrice weekly for 8 weeks, vehicle alone, Pg-LPS and intramuscular delivery of pseudotyped AAV2/1-TNFR:Fc vector (1 × 1011 DNase I-resistant particles) or AAV2/1-TNFR:Fc vector delivered to naive animals. AAV2/1-TNFR:Fc therapy led to sustained therapeutic levels of serum TNFR protein and protected against Pg-LPS-mediated loss of bone volume and density. Furthermore, AAV2/1-TNFR:Fc administration reduced local levels of multiple proinflammatory cytokines and osteoclast-like cells at the periodontal lesions. These findings suggest that delivery of AAV2/1-TNFR:Fc may be a viable approach to modulate periodontal disease progression.

Influence of Interimplant Distance on Papilla Formation and Bone Resorption: A Clinical-radiographic Study in Dogs

Implant esthetics has been the focus of attention for the past decade, and one vital issue is the effect of interimplant distance on interimplant papilla formation and crestal bone loss. The aim of this study was to evaluate the effect of 1, 2, and 3 mm of interimplant distance on papilla formation and crestal resorption in submerged and nonsubmerged Ankylos implants after prosthetic restoration. Bilateral mandibular premolars of 7 dogs were extracted, and after 12 weeks each dog received 8 implants. Implants were placed so that 3 interimplant distances were created at 1 mm (group 1), 2 mm (group 2), and 3 mm (group 3). The sides and the position of the groups were randomly selected. Twelve weeks after placement, the implants received metallic prostheses that allowed 5 mm of space between the prosthetic contact point (CP) and the crestal bone (CB). After 8 weeks, the distance between the CP and the papilla (CP-P) and the gingival height at the distal proximal aspect of the prosthesis (CP-DE) was clinically measured. Radiographic images were obtained to measure the distance of the CP to the CB within the interimplant surfaces (CP-IP) and adjacent to the edentulous surfaces (CP-ED). The clinical measurement of CP-P for submerged and nonsubmerged implants was 3.57+/-1.17 mm and 3.10+/-0.82 mm for group 1, 3.57+/-0.78 mm and 3.16+/- 0.87 mm for group 2, and 3.35+/- 0.55 mm and 3.07+/-0.93 mm for group 3. The CP-DE was 3.25+/-0.77 mm for submerged and 2.78+/- 0.64 mm for nonsubmerged implants. The CP-IP for the submerged and nonsubmerged implants was 6.91+/-0.95 mm and 7.68+/-2.73 mm for group 1, 7.46+/-1.43 mm and 5.87+/-1.71 mm for group 2, and 7.72+/-0.81 mm and 7.59+/-1.33 mm for group 3. The CP-ED was 6.77+/-1.33 mm for submerged implants and 6.03+/-1.58 mm for nonsubmerged implants. There were no statistical significant differences for any of the measured parameters. We conclude that when the distance from the CP to the CB was 5 mm, interimplant distances of 1 to 3 mm did not affect papilla formation or crestal resorption of submerged or nonsubmerged implants in the dog model.

Changes in Masticatory Performance and Quality of Life in Individuals With Chronic Periodontitis

BACKGROUND This study evaluates the effect of periodontitis on masticatory performance and quality of life index. METHODS Patients (n = 24; 23 to 76 years of age) with periodontal conditions ranging from healthy to generalized disease categorized by the alveolar bone height-to-tooth length (AB/T) ratio were separated into the following two groups: control (AB/T >50%) and test (AB/T <50%). The masticatory performance was evaluated through continuous mastication of a special device called a biocapsule. The Brazilian Oral Health Impact Profile (OHIP-14Br) questionnaire was used to assess the oral health-related quality of life. The Student t test was applied for independent samples (P <0.05) to evaluate the masticatory performance, and the Mann-Whitney U test was used to determine quality of life (P <0.05). RESULTS There was a statistically significant difference in masticatory efficiency between groups (P = 0.006). Statistically significant differences were also observed in the following parameters: 1) physical pain (P = 0.003); 2) psychologic discomfort (P = 0.008); 3) physical disability (P = 0.033); and 4) OHIP-14Br total score (P = 0.001). The control group achieved the best indicators. Both the masticatory performance and quality of life indicators showed significant correlation with the alveolar bone height. CONCLUSION The loss of periodontal supporting structures has negative effects on the masticatory performance and quality of life.