IL-1beta and TNF-alpha regulate IL-6-type cytokines in gingival fibroblasts

Interleukin-6 (IL-6)-type cytokines are pleiotropic molecules capable of stimulating bone resorption and expressed by numerous cell types. In the present study, we tested the hypothesis that gingival fibroblasts may exert local osteotropic effects through production of IL-6 and related cytokines. IL-6-type cytokine expression and regulation by IL-1beta and tumor necrosis factor-alpha (TNF-alpha) were studied in fibroblasts from the non-inflamed gingiva of healthy individuals. Constitutive mRNA expression of IL-6, IL-11, and leukemia inhibitory factor (LIF), but not of oncostatin M (OSM), was demonstrated, as was concentration-dependent stimulation of IL-6 and LIF mRNA and of protein by IL-1beta and TNF-alpha. IL-11 mRNA and protein were concentration-dependently stimulated by IL-1beta. The signaling pathway involved in IL-6 and LIF mRNA stimulation involved MAP kinases, but not NF-kappaB. The findings support the view that resident cells may influence the pathogenesis of periodontal disease through osteotropic IL-6-type cytokine production mediated by activation of MAP kinases. Abbreviations: IL-1alpha (interleukin-1alpha); IL-1beta (interleukin-1beta); IL-6 (interleukin-6); IL-11 (interleukin-11); LIF (leukemia inhibitory factor); OSM (oncostatin M); alpha(1)-coll. I (alpha(1)-collagen I); ALP (alkaline phosphatase); BMP-2 (bone morphogenetic protein-2); OC (osteocalcin); BSP (bone sialoprotein); TNFR I (tumor necrosis factor receptor I); TNFR II (tumor necrosis factor receptor II); IL-1R1 (interleukin-1 receptor 1); GAPDH (glyceraldehyde-3-phosphate dehydrogenase); RPL13A (ribosomal protein L13A); mRNA (messenger ribonucleic acid); cDNA (complementary deoxyribonucleic acid); PCR (polymerase chain-reaction); BCA (bicinchoninic acid); ELISA (enzyme-linked immunosorbent assay); alpha-MEM (alpha modification of Minimum Essential Medium); and FCS (fetal calf serum).     

The effect of autogenous cancellous bone grafts on gealing of experimental furcation defects in dogs

Chronic, through-and-through, furcation defects were created in mandibular premolars of six beagle dogs. These defects were surgically treated without autogenous, cancellous, bone grafts. Healing sockets in the maxilla serged as donor sites. Block specimens were removed after eight weeks. All teeth from all dogs showed some reattachment after treartment as evidenced by newly formed cementum. None of the specimens showed complete regeneration, i.e.a periodontal membrane with new cementum all aroune the fornix of the furcation. Histometric measurements showed that the use of osseous grafts did not improve the results in the present experimental model.     

Fracture process characterization of fiber-reinforced dental composites evaluated by optical coherence tomography, SEM and optical microscopy

This study used optical coherence tomography (OCT) compared to scanning electron microscopy (SEM) and optical microscopy (OM) to evaluate qualitatively crack propagation and final fracture in restorative composite materials - Filtek Z250 and Filtek Z350 (3M ESPE) - with fiber reinforcement after cyclic loading. Samples were made using a split mold. Initially, 3-point bending tests were performed to determine the maximum force and tension at the fracture moment using samples without fiber reinforcement. Then, mechanical cycling tests were performed using samples with glass fiber embedded internally. The failures were analyzed using the 3 methods described before. OCT permitted good characterization of internal crack propagation of the dental composites, which, however, could not be visualized by either SEM or OM. OCT was proven to be laboratory research tool that is easy to use, does not require any specific preparation of the samples, and is less expensive than SEM.     

Skeletal effects of bite jumping therapy on the mandible - removable vs. fixed functional appliances

AUTHORS: Shen G, Hagg U, Darendeliler MA. OBJECTIVE: Based on an extensive review of the literature, the aim of this study was to explore the mainstream consensus on the controversial topic of whether the bite jumping treatment could enhance mandibular growth. DESIGN: The data for removable and fixed functional appliances were respectively comprehended and analyzed with regard to their attributes in mandibular growth modification. Furthermore, numerous reported findings were assessed by relating them to some important factors influencing the effects of bite jumping, such as treatment timing, treatment duration and post-treatment follow-up, to allow for a more objective and accurate evaluation. RESULTS: The key differences between removable and fixed appliances are working hours (intermittent vs. continuous), length of treatment time (long vs. short), optimal treatment timing (before puberty growth vs. at or after puberty spurt), and mode of bite-jumping (considerable vertical opening vs. limited vertical opening). These different features lead to different treatment effects on mandibular and TMJ growth, such as the intensity of possibly increased growth (clinically less significant vs. significant), the direction of enhanced growth (vertical vs. horizontal), and the stability of treatment changes (unstable vs. stable). The short-term or long-term post-treatment relapse mainly relates to the rebound of dental position. CONCLUSION: The immediate effects of bite jumping functional appliances on the mandibular growth enhancement are convincing during actual treatment. This extra gain of growth might be sustainable during the short-term and long-term post-treatment period.     

HLA-DR4 and salivary immunoglobulin A reactions to oral streptococci

The aim of this study was to describe and compare salivary immunoglobulin A (IgA) antibody reactions to extracts of strains of three oral streptococci in human leukocyte antigen (HLA)-DR4-positive and -DR4-negative subjects. Whole paraffin-stimulated saliva samples were collected from 27 apparently healthy subjects. Previous HLA typing showed that 20 subjects were DR4 positive and 7 were DR4 negative. HLA-DRB1*04 subtyping was performed among the DR4-positive subjects. Whole-cell antigen extracts from Streptococcus mutans (KPSK 2), Streptococcus sobrinus (OMZ 65) and Streptococcus parasanguis (Nt 62) were separated in SDS-PAGE. The antigens were immunoblotted with diluted saliva (Western blot), scanned and analyzed in a computer system. All immunoblot bands were recorded in DR4-positive and DR4-negative saliva pools, and bands with an optical density >or=0.1 were selected for analysis in individual salivas. The DR4-negative subjects in general had more immunoblot bands and more distinct bands than did the DR4-positive subjects. A higher concentration of total IgA in saliva was correlated with more bands, especially to antigens separated from S. mutans. When the number of bands was calculated per IgA unit, significant differences were observed between DR4-positive and DR4-negative salivas. This was particularly seen for S. mutans and S. parasanguis. As the number of bands was analyzed in relation to DR4 subgroups, DRB1*04, there was a lower salivary IgA activity to S. mutans in the DRB1*0401 and *0404. The variable level of correlation previously demonstrated for S. mutans colonisation and serologically defined DR4 positive subjects might be explained by the heterogeneity in this group, and the relation should be sought on a subgroup level.     

Shoulder complaints after nerve sparing neck dissections

The purpose of the study was to analyse the prevalence of shoulder complaints after nerve sparing neck dissection at least 1 year after surgery, and to analyse the influence of radiation therapy on shoulder complaints. Patients were interviewed for shoulder complaints, and patients filled out the shoulder disability questionnaire to evaluate shoulder disability in daily activities. In total 137 patients; 51 after modified radical neck dissection (MRND), 21 after postero-lateral neck dissection (PLND), and 65 after supraomohyoid neck dissection (SOHND) were analysed. After MRND 33.3% of the patients experienced shoulder complaints, after PLND 66.7%, and after SOHND 20% of the patients experienced shoulder complaints. Type of neck dissection was significantly (P < 0.001) related to shoulder complaints. Outcome on the shoulder disability questionnaire also showed a significant (P < 0.01) difference in outcome for type of neck dissection. The prevalence of shoulder complaints after SOHND are low, and reduce disability in daily activities. Radiation therapy does not have a significant effect on shoulder complaints and disability.     

The combined analgesic effect of gabapentin and transdermal fentanyl patch on acute and chronic pain after maxillary cancer surgeries

Abstract

Purpose of this study was to evaluate the combined analgesic effect of gabapentin and transdermal fentanyl patch, on acute and chronic pain after surgery for maxillary cancer.

Study design

The Study was double blind and prospective. 100 subjects belonging to ASA grade I and II, 30–50 years age group, scheduled for maxillary cancer surgery were randomized into two groups; treatment group (GT): to receive gabapentin, transdermal fentanyl patch or control group ©: two placebos. For acute postoperative pain (Visual Analogue Score) and analgesic requirements were assessed 2, 4, 8 hours and 7 days after surgery. Subjects were also assessed for chronic pain 2, 4, 6 months later.

Results

Subjects in treatment group required lesser dose of analgesic, as compared to control group, in the post operative period. Visual Analogue Scores were also significantly lower in the treatment group throughout the post operative period. Occurrence of side effects was non significant between both groups. 2, 4 and 6 months after surgery, 40, 35 and 28 subjects respectively, out of total 45 subjects of the control group, reported chronic pain. In comparison, 25, 10 and 4 subjects out of 42 subjects in the treatment group reported chronic pain 2, 4, 6 months respectively after surgery. 15, 10 and 6 out of 45 of the control group required analgesics, whereas 2, 0 and 0 out of 42 in the treatment group, required analgesics respectively 2, 4 and 6 months after surgery

Conclusion

Acute and chronic pain after maxillary cancer surgery is significantly reduced by multimodal analgesia.