Analysis of Biomarkers and Marginal Bone Loss in Platform-Switched and Nonplatform-Switched Implants: A Randomized Clinical Trial.

Objectives: To compare the peri-implant crevicular fluid (PICF) biomarker levels, peri-implant status, and marginal bone level (MBL) differences of implants restored with randomly assigned nonplatform-switched (NPS) or platform-switched (PS) abutments. Methods: Ninety-four implants in 27 subjects were included in this study. Receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG), interleukin-1ß (IL-1ß), monocyte chemotactic protein-1 (MCP-1) levels in PICF, peri-implant health, and the change in the MBL were evaluated at the time of restoration (T 1) and after 12 months (T 2). Results: The IL-1ß levels decreased and the RANKL, OPG, and MCP-1 levels increased from T 1 to T 2 (P < 0.05) in both groups. RANKL/OPG ratio at T 1, MCP-1 levels at T 2, and the MCP-1 change from T 1 to T 2 were lower in the PS group than in the NPS group (P < 0.05). MBL change was lower (0.51 ± 0.31 mm) in the PS group than that (0.75 ± 0.29 mm) in the NPS group at T 2 (P < 0.001). Peri-implant health status between the study groups was negligible. Conclusion: PS was superior to NPS regarding the preservation of MBL. Higher MCP-1 levels, altered RANKL/OPG ratio, and lower OPG levels in the NPS group could be associated with subclinical peri-implant bone remodeling.

Saliva profiles in children with congenital heart disease.

PURPOSE: The low salivary pH and buffering capacity are caused by using heart failure medications. For this reason oral health should be supported in cardiac patients, it is necessary that they attend dental clinics for regular follow up. The aim of this study is to evaluate the relationship between the salivary oxidative stress markers and salivary pH, salivary buffering capacity, salivary flow rate and dental caries of children with congenital heart disease (CHD). MATERIALS AND METHODS: This cross sectional study was carried out with 42 CHD and 42 healthy children. The participants' gender, age, general health and medications, and caries scores (dfs/ DMFS) were written down, then their unstimulated saliva samples were collected. These specimens were evaluated in terms of the salivary secretion rate, salivary buffering capacity, pH, protein levels, superoxide dismutase (SOD), ferric reducing antioxidant power (FRAP), the thiobarbituric acid reactive substances (TBARS), protein carbonyl, protein thiols, total sialic acid. RESULTS: Both groups showed caries at similar levels. The salivary pH and buffering capacity were significantly less in the children with CHD than in the controls. The levels of TBARS and protein carbonyl were significantly higher in the children with CHD than in the controls. There was not any significant difference relating to the mean salivary secretion rate, protein levels, SOD, FRAP, protein thiols and total sialic acid. CONCLUSION: The elevated TBARS and protein carbonyl levels in the patients with CHD were observed as an indicator of the free radical damage leading to oxidative stress.

Compomers Reinforced with Bioactive Glass and Hydroxyapatite Particles.

PURPOSE: To understand the effect of the addition of hydroxyapatite (HA) and bioactive glass (BAG) to compomer restorative materials on the remineralisation capacity of the material. MATERIALS AND METHODS: 1%, 2%, 3% and 4% w/w HA and BAG particles were added mechanically to the compomers. To examine the resistance to demineralisation, Class V cavities were prepared in extracted teeth and restored with experimental filling materials. Demineralised lesions were created in 72 enamel samples. Vickers microhardness measurements of samples were performed at three different areas including the margin of the restoration, the varnish-protected enamel and the exposed enamel areas. Measurements performed on protected enamel were used as reference enamel values for each group. SEM was used to evaluate the surface texture of the specimens. The statistical analyses were performed by one-way ANOVA, Tukey's HDS and paired-samples t-tests. RESULTS: BAG and HA groups revealed higher microhardness values at the exposed enamel and exposed marginal enamel than did the control group (p = 0.001). 3% and 4% HA and BAG groups produced higher microhardness values than did 1% modified groups on exposed enamel (p = 0.001). 4% HA group revealed the highest microhardness values on marginal exposed enamel (p = 0.001). 2%, 3%, 4% and HA, as well as 3% and 4% BAG groups showed higher microhardness values than did the control group on marginal exposed enamel at 20 µm depth (p = 0.001). SEM images revealed that HA and BAG particles were not distributed homogeneously and the particles seemed to be grouped in the matrix. CONCLUSIONS: Within the limits of this study, the addition of the BAG and HA into compomers improved the demineralisation resistance properties of enamel, depending on the amount of additive.

The effects of supplemental melatonin administration on the healing of bone defects in streptozotocin-induced diabetic rats.

OBJECTIVE: The aim of this study was to investigate histologic and biochemical effects of supplemental melatonin administration on bone healing and antioxidant defense mechanism in diabetic rats. MATERIAL AND METHODS: Eighty-six Sprague-Dawley male rats were used in this study. Diabetes mellitus was induced by intraperitoneal (i.p.) administration of 65 mg/kg streptozotocin (STZ). Surgical bone defects were prepared in the tibia of each animal. Diabetic animals and those in control groups were treated either with daily melatonin (250 µg/animal/day/i.p.) diluted in ethanol, only ethanol, or sterile saline solution. Rats were humanely killed at the 10th and 30th postoperative days. Plasma levels of Advanced Oxidation Protein Products (AOPP), Malondialdehyde (MDA), and Superoxide Dismutase (SOD) were measured. The number of osteoblasts, blood vessels and the area of new mineralized tissue formation were calculated in histologic sections. RESULTS: At the 10th day, DM+MEL (rats receiving both STZ and melatonin) group had significantly higher number of osteoblasts and blood vessels as well as larger new mineralized tissue surfaces (p<0.05 for each) when compared with DM group. At the 30th day, DM group treated with melatonin had significantly lower levels of AOPP and MDA than those of DM group (p<0.05). CONCLUSION: Melatonin administration in STZ induced diabetic rats reduced oxidative stress related biomarkers and showed beneficial effects on bone healing at short term.

The effects of supplemental melatonin administration on the healing of bone defects in streptozotocin-induced diabetic rats

ABSTRACT Diabetes mellitus (DM) causes an increased production of free radicals that can impair bone healing. Melatonin is a hormone secreted mainly by the pineal gland, which participates in the neutralization process of free radicals. Objective The aim of this study was to investigate histologic and biochemical effects of supplemental melatonin administration on bone healing and antioxidant defense mechanism in diabetic rats. Material and Methods Eighty-six Sprague-Dawley male rats were used in this study. Diabetes mellitus was induced by intraperitoneal (i.p.) administration of 65 mg/kg streptozotocin (STZ). Surgical bone defects were prepared in the tibia of each animal. Diabetic animals and those in control groups were treated either with daily melatonin (250 μg/animal/day/i.p.) diluted in ethanol, only ethanol, or sterile saline solution. Rats were humanely killed at the 10th and 30th postoperative days. Plasma levels of Advanced Oxidation Protein Products (AOPP), Malondialdehyde (MDA), and Superoxide Dismutase (SOD) were measured. The number of osteoblasts, blood vessels and the area of new mineralized tissue formation were calculated in histologic sections. Results At the 10th day, DM+MEL (rats receiving both STZ and melatonin) group had significantly higher number of osteoblasts and blood vessels as well as larger new mineralized tissue surfaces (p<0.05 for each) when compared with DM group. At the 30th day, DM group treated with melatonin had significantly lower levels of AOPP and MDA than those of DM group (p<0.05). Conclusion Melatonin administration in STZ induced diabetic rats reduced oxidative stress related biomarkers and showed beneficial effects on bone healing at short term.

Evaluation of prolidase activity and oxidative stress in patients with oral lichen planus and oral lichenoid contact reactions.

OBJECTIVE: The aim of this study was to evaluate prolidase activity and oxidative stress in patients with oral lichen planus (OLP) and oral lichenoid contact reactions (OLCR) using serum and salivary samples and to compare these biomarkers with each other as well as with a group of healthy subjects in order to be able to opine their role in the estimation of OLP and OLCR. PATIENTS AND METHODS: Eighteen recently diagnosed patients with OLP, 32 patients with OLCR and 18 healthy controls with matched periodontal status were recruited to the study. Prolidase activity, lipid peroxidation product malondialdehyde (MDA), sialic acid (SA), and advanced oxidation protein products (AOPPs) levels in both serum and saliva were determined. Additionally, salivary flow rate and its buffering capacity were estimated. Statistical analyses were performed using the chi-square test, t-test, Mann-Whitney U-test, and Spearman's rho correlation coefficient. RESULTS: No statistically significant differences were observed between the study groups and the control group regarding to the basic characteristics and the periodontal status (P > 0.05). There were no statistically significant differences between OLP and OLCR groups regarding to the distribution of lesions' type, severity, and location (P > 0.05). No significant differences were found between the two study groups with regard to Prolidase activity, MDA, SA, and AOPPs (P ˃ 0.05), whereas statistically significant differences were found between the two study groups and the control group with regard to all evaluated parameters except of serum prolidase (P ˂ 0.01). Moderate correlation was found between salivary MDA and the OLP/OLCR lesion severity, whereas a weak correlation was observed between serum SA and the OLP/OLCR lesion severity (P ˂ 0.05). CONCLUSIONS: The findings of this study suggest an increased prolidase activity and oxidative stress and imbalance in the antioxidant defense system in biological fluids of patients with OLP and OLCR when compared with the healthy subjects. Both OLP and OLCR patients revealed almost similar prolidase activity and oxidative stress levels although these two conditions have different etiopathogenesis.

Effects of a regular exercise program on biochemical parameters of type 2 diabetes mellitus patients.

BACKGROUND: We aimed to investigate the effects of a regular exercise program on exercise capacity, blood biochemical profiles, certain antioxidant and oxidative stress parameters of type 2 Diabetes mellitus (DM) patients. METHODS: Thirty one type 2 DM patients (ages ranging from 42-65 years) who have hemoglobin A1c (HbA1c) levels ≥7.5% and ≤9.5% were included to study and performed two cardiopulmonary exercise tests (CPET) before and after the exercise program. Subjects performed aerobic exercise training for 90 minutes a day; 3 days a week during 12 weeks. Blood samples were collected to analyze certain oxidant and antioxidant parameters (advanced oxidation protein products [AOPP], ferric reducing ability of plasma [FRAP], malondialdehyde [MDA], and sialic acid [SA]), blood lipid profile, fasting blood glucose (FBG) and HbA1c. RESULTS: At the end of the program HbA1c and FBG, triglyceride (TG) and very-low-density lipoprotein (VLDL) levels decreased and high-density lipoprotein (HDL) increased significantly (P=0.000, P=0.001, P=0.008, P=0,001 and P=0.02, respectively). AOPP, FRAP, SA levels of the patients increased significantly following first CPET (P=0.000, P=0.049, P=0.014 respectively). At the end of the exercise program AOPP level increased significantly following last CPET. Baseline SA level increased significantly following exercise program (P=0.002). CONCLUSIONS: We suggest that poor glycemic control which plays the major role in the pathogenesis of DM and its complications would be improved by 12 weeks of a regular exercise program. Whereas the acute exercise induces protein oxidation, regularly aerobic training may enhance the antioxidant status of type 2 DM patients.

Long term consequences on spatial learning-memory of low-calorie diet during adolescence in female rats; hippocampal and prefrontal cortex BDNF level, expression of NeuN and cell proliferation in dentate gyrus.

Calorie restriction (CR) is argued to positively affect general health, longevity and normally occurring age-related reduction of cognition. Obesity during adolescence may adversely affect cognition in adulthood but, to date effects of CR have not been investigated. We hypothesized that feeding with as low as 15% low-calorie diet (LCD) during adolescence would increase hippocampal and prefrontal BDNF (Brain-derived neurotrophic factor) levels, proliferative cells and neuron numbers in dentate gyrus (DG), thus positively affecting spatial memory in adulthood. Spatial learning-memory function was improved in adult female Sprague-Dawley rats fed with LCD during adolescence. PCNA (Proliferating cell nuclear antigen-cell proliferation marker) expressing cells and NeuN (Neuronal nuclear antigen-neuron marker) expressing cells in hippocampus DG which are critically involved in memory were increased. Hippocampus and prefrontal cortex BDNF levels were increased while serum glucose levels and level of lipid peroxidation indicator malondialdehyde in serum and hippocampus were reduced. Our unique results suggest that improved cognition in adult rats with LCD feeding during adolescence may result from the increase of neurogenesis and BDNF. These findings reveal the importance of nutrition in adolescence for cognitive function in adulthood. Our results may be useful for further studies aiming to treat age-related cognitive impairments.