Increased activity of the antioxidants systems modulate the oxidative stress in saliva of toddlers with early childhood caries

ObjectiveThis study aimed to evaluate the oxidative stress levels and the enzymatic and non-enzymatic antioxidant systems in saliva of toddlers with severe early childhood caries (S-ECC).DesignUnstimulated saliva samples were collected at the morning from 0 to 3 year-old S-ECC (n = 30) or caries-free (CF) children (n = 30/group) for evaluation of oxidative stress (OS) and total antioxidant capacity (TAC), which were measured by the ferric reducing antioxidant power (FRAP) assay, as well as to assess the activity of enzymatic (superoxide dismutase, SOD) and non-enzymatic (uric acid, UA) antioxidant systems, respectively. Data were analyzed by Student’s t-test (p < 0.05).ResultsSignificantly higher protein levels were observed in saliva of S-ECC children (0.083 mg/mL) than in the CF group (0.070 mg/mL). Oxidative damage was significantly lower in saliva of S-ECC children (0.0019 μmol/L/mg protein) than in CF children (0.0039 μmol/L/mg protein), while salivary TAC (61.5 μmol/L), SOD activity (36.6 UE/mL) and uric acid (7.05 mg/mL) were significantly higher in saliva of S-ECC when compared to the CF group (49.1 μmol/L, 26.8 UE/mL and 5.02 mg/mL, respectively for TAC, SOD and UA).ConclusionOxidative stress levels were significantly lower in saliva of S-ECC children, what might be associated with the increased activity of salivary enzymatic (SOD) and non-enzymatic (uric acid) antioxidant systems.     

Evaluation of scalp hair nickel and chromium level changes in patients with fixed orthodontic appliance: a one-year follow-up study

Background and objectives: The release of metal ions from orthodontic appliances is part of the dissolution and biomechanical processes of alloys. Nickel (Ni) and chromium (Cr) are the elements commonly used in the manufacture of various components of fixed orthodontic appliances, including bands, brackets and wires. This study was aimed to measure the Ni and Cr ions levels in the scalp hair of patients treated with fixed orthodontic appliances in comparison of the control group.

Materials and methods: The patient group consisted of 24 patients treated with fixed orthodontic appliances for one year, while the control group included 28 healthy individuals without orthodontic appliances. Analysis of the Cr and Ni was performed using atomic absorption spectrophotometer by graphite furnace method. The data were analyzed via student and paired samples t-test and ANOVA repeated measurement test.

Results: After one year, the levels of Ni and Cr in two groups showed significant differences (0.086?±?0.007 and 0.258?±?0.009 µg/g for control group and 0.149?±?0.010 and 0.339?±?0.013 µg/g for patient group, respectively for Ni and Cr, p?Conclusion: Due to the slightly elevated levels of Ni and Cr ions in the scalp hair of patients treated with fixed orthodontic appliances and considering the cytotoxic and allergic effects of these ions, changing the ingredients in fixed orthodontic appliances is suggested for the future.     

Elemental ion release from four different fixed prosthodontic materials

ObjectiveElemental release is important because it plays a significant role in material biocompatibility. The aim of this study was to investigate the release of metal ions from four fixed prosthodontic materials.MethodsSpecimens were prepared using the conventional lost wax technique for gold and nickel–chromium (Ni–Cr) alloys, and by cutting blocks and bar for CAD–CAM ceramic and stainless-steel (St-St) alloy, respectively. All specimens were polished (600 grit SiC paper), and ultrasonically cleaned with ethanol for 5 min. After they were immersed in 0.9% sodium chloride (NaCl) and 1% lactic acid, and were kept at 37 °C for 7 days, the elemental release (μg/cm²) from each material was analyzed by using inductively coupled plasma mass spectroscopy. The rate (n = 5) was statistically analyzed by ANOVA/Tukey test (p < 0.05). Two immersion blank solutions were used as a negative control group.ResultsHigher elemental release (mean ± S.D.) of all elements from all materials was evident into the lactic acid solution except for Ag. In the gold alloy, there was significant difference (p < 0.05) between Zn and other released elements in the NaCl solution, and it also revealed significant difference between Pd or Ag and Cu which detection value was more than Zn (but no statistical difference) into lactic acid solution. The Ni was significantly more released from Ni–Cr alloy than the other elements into both NaCl and lactic acid solutions. The same was observed for Fe released from St-St alloy. There was more significant release of K than Al from CAD–CAM ceramic in only NaCl solution.SignificanceTransient exposure of tested materials to an acidic environment is likely to significantly increase the elemental release from them. The significant higher release of Ni from Ni–Cr alloy, and Zn, Cu from gold alloy was evident.     

A comparison of salivary IgA in children with Down syndrome and their family members

The aim of this study was to compare total IgA in the whole saliva of children with Down syndrome with levels in sibling and parent groups. IgA measurements were presented as the concentration in saliva (μg/ml) and also adjusted for salivary flow rate (SFR; μg/min). Twenty children with Down syndrome, ten siblings and twenty parents were recruited. Stimulated whole saliva was collected from the participants and SFR calculated. The measurement of salivary IgA (sIgA) was carried out using an indirect competitive Enzyme-Linked Immunosorbent Assay. The difference in the mean SFR between children with Down syndrome, parents and siblings were not statistically significant. The mean salivary concentration of IgA was higher in children with Down syndrome (95.1 μg/ml) compared with siblings (48.3 μg/ml; p = 0.004). When adjusted for SFR children with Down syndrome had mean sIgA levels of 98.8 μg/min and the siblings 48.6 μg/min (p = 0.008). The children with Down syndrome had sIgA levels similar to those of the parents (92.5 μg/ml; 93.2 μg/min). There was a positive correlation between age and sIgA concentration in the siblings (p = 0.008) but not for children with Down syndrome (p = 0.363). This suggests that under similar environmental influences, the levels of sIgA in children with Down syndrome are higher than in the siblings, from a very young age.     

In vitro dentine remineralization with a potential salivary phosphoprotein homologue

ObjectiveAdvantages of introducing a salivary phosphoprotein homologue under standardized in vitro conditions to simulate the mineral-stabilizing properties of saliva have been proposed. This study longitudinally investigates the effects of casein, incorporated as a potential salivary phosphoprotein homologue in artificial saliva (AS) solutions with/without fluoride (F) on in vitro dentine lesion remineralization.DesignThin sections of bovine root dentine were demineralized and allocated randomly into 6 groups (n = 18) having equivalent mineral loss (ΔZ) after transverse microradiography (TMR). The specimens were remineralized using AS solutions containing casein 0 μg/ml, F 0 ppm (C₀–F₀); casein 0 μg/ml, F 1 ppm (C₀–F₁); casein 10 μg/ml, F 0 ppm (C₁₀–F₀); casein 10 μg/ml, F 1 ppm (C₁₀–F₁); casein 100 μg/ml, F 0 ppm (C₁₀₀–F₀) or casein 100 μg/ml, F 1 ppm (C₁₀₀–F₁) for 28 days with TMR taken every 7 days.ResultsSurface mineral precipitation, evident in group C₀–F_1, was apparently inhibited in groups with casein incorporation. Repeated measures ANOVA with Bonferroni correction revealed higher ΔZ for non-F and non-casein groups than for their counterparts (p < 0.001). Subsequent multiple comparisons showed that mineral gain was higher (p < 0.001) with 10 μg/ml casein than with 100 μg/ml when F was present in the earlier stages of remineralization, with both groups achieving almost complete remineralization after 28 days.ConclusionCasein is a potential salivary phosphoprotein homologue that could be employed for in vitro dentine remineralization studies. Concentration related effects may be clinically significant and thus must be further examined.     

Evaluation of the gingival inflammation in pregnancy and postpartum via 25-hydroxy-vitamin D3, prostaglandin E2 and TNF-α levels in saliva

BackgroundPhysiological changes and immunological modifications occur during pregnancy. The clinical and biological features of periodontal infections are affected by pregnancy. The aim of the present study was to evaluate saliva levels of 25-hydroxy-vitamin D3 (25(OH)D3), prostaglandin E2 (PGE₂) and TNF-alpha (TNF-α) in pregnancy, postpartum and non-pregnant controls.MethodsWhole saliva samples together with full-mouth clinical periodontal recordings were obtained from 59 pregnant, 47 post partum and 70 systemically healthy non-pregnant women. Groups were also evaluated according to the periodontal health status. 25(OH)D3, PGE₂ and TNF-α levels in the saliva samples were determined by enzyme-linked immunoassays. Data were statistically tested by nonparametrical tests.ResultsSaliva TNF-α and PGE₂ levels were significantly lower and 25(OH)D3 levels were significantly higher in the pregnant group than postpartum group (p < 0.0001). Saliva TNF-α and 25(OH)D3 levels were significantly higher and PGE₂ levels were significantly lower in the control group than postpartum group (p < 0.0001). In the pregnant healthy, gingivitis and periodontitis groups saliva TNF-α levels were significantly lower than postpartum and control counterparts (p < 0.0001, p = 0.032, p = 0.003 and p = 0.013; p = 0.027; p = 0.007, respectively). In control healthy, gingivitis and periodontitis groups saliva 25(OH)D3 levels were significantly higher than the postpartum counterparts (p < 0.0001, p < 0.0001, p = 0.002, respectively). In the control healthy and gingivitis groups saliva 25(OH)D3 levels were significantly higher than pregnant healthy and gingivitis (p < 0.0001).ConclusionsIn conclusion, within the limits of the present study it seems that pregnancy have an effect on parameters in saliva in relation to the periodontal status of the women. Further studies are required for better understanding of the impact of periodontal diseases on pregnancy or otherwise.     

Characterization of two Ni–Cr dental alloys and the influence of casting mode on mechanical properties

PurposeThe aim of this study was to evaluate the tensile strength, elongation, microhardness (MHV), composition and microstructure of two Ni–Cr based alloy, cast under different casting conditions.MethodsBefore casting, the alloy ingots were evaluated as regards composition (EDX) and microstructure (Optical microscopy, SEM and EDX). The casting conditions were as follows: electromagnetic induction in an environment controlled with argon (EWA), electromagnetic induction in an environment under vacuum (EWV), electromagnetic induction without atmosphere control (EWNC) and blowtorch (BT). For each condition, 16 specimens were obtained, each measuring 25 mm high and 2.5 mm in diameter. The ultimate tensile strength (UTS) and elongation (EL) tests were performed in a Kratos machine (1.0 mm/min). Fractured specimens were embedded in bakelite resin and polished for Vickers Microhardness analysis (1000 g/10 s) with 4 penetrations in each specimen. The UTS, EL and MHV results were evaluated for two-way ANOVA and Tukey's test (α = 0.05).ResultsThe cross-product interaction was statistically significant for all properties evaluated (p < 0.0001), lower UTS, VHN and higth elongation means were observed for the Ni–Cr–Mo–Be alloy tested when cast under the induction/argon (p < 0.05). Higher UTS means were found for Ni–Cr–Mo–Ti alloy tested when cast under the induction/vacuum, and induction/air and flame/air condition (p < 0.05). The two alloys show a microstructure with a dendritic formation with the presence of eutectic presence.ConclusionThe Ni–Cr–Mo–Ti alloy showed higth UTS, MHV and lowest EL comparaded with the tradicional Ni–Cr–Mo–Be, that show lowest UTS, MHV and higter EL when cast on induction/argon.     

Microbial profile of dental plaque associated to white spot lesions in orthodontic patients immediately after the bracket removal

ObjectiveDenaturing Gradient Gel Electrophoresis (DGGE) is suggested to predict caries risk in young children. Such a tool would be valuable in orthodontic patients undergoing treatment with fixed appliances. In this cross-sectional study the applicability of DGGE and conventional microbiology for caries risk assessment in orthodontic patients were assessed.DesignDental plaque was obtained from orthodontic patients immediately prior to bracket removal. Presence of white spot lesions (WSL) was assessed immediately post debracketing. DGGE-patterns and band counts were assessed using varying automated band detection settings and compared to visually detected bands to determine optimum settings. Optimum settings were used to compare band patterns in subjects with or without WSL. Microbiological samples were assessed for total colony forming units (CFU’s) and percentages of aciduric flora, Streptococcus mutans, Lactobacillus spp. and Candida albicans.ResultsThirty-seven subjects were included with a mean age of 15.4 yr (SD 1.6 yr; 28 with WSL; 9 without WSL). Depending on settings, DGGE outcomes were different. Optimum minimum profiling absolute to the most intense band of 4% showed no significant difference in band numbers for subjects with or without WSL (p = 0.845). Optimum settings for minimum profiling relative to the most intense band of 15% showed significant lower band numbers for subjects with WSL than those without (p = 0.007). No differences between groups were observed for microbiological parameters.ConclusionThe analysis of DGGE-patterns is ambiguous. Software settings significantly affected outcomes. DGGE-patterns and band numbers like CFU counts were not predictive with respect to WSL formation in these orthodontic patients.     

Periodontal status following self-ligature versus archwire ligation techniques in orthodontically treated patients—Clinical,microbiological and biochemical evaluation

ObjectivesThe present study was designed to evaluate the changes in microbial flora and periodontal status, with a concomitant evaluation of the changes in the aspartate aminotransferase activity obtained from the gingival crevicular fluid after the orthodontic treatment with self-ligature versus archwire ligation techniques.MethodsTwenty-two orthodontic patients were included in this study. Using a split mouth design for each patient according to the ligation techniques, one site received a self-ligature technique while the other an archwire ligature.ResultsThe results revealed that all microbial counts, after bonding the orthodontic appliances, in the archwire ligature sites were slightly higher than those in the self-ligature sites at different monitoring periods. Compared with those in the self-ligature group, the probing depth and the clinical attachment level showed significantly increased in the archwire ligature group (P ≤ 0.01). Moreover, the aspartate aminotransferase enzymatic activity was significantly greater at the archwire sites, compared to that at the self-ligature sites (P ≤ 0.01).ConclusionThe archwire ligature technique caused microbial colonization and aspartate aminotranferase activity to be greater than the self-ligature technique. Therefore, the use of self-ligature is the recommended wire ligation technique in order to prevent periodontal tissue destruction.     

Saliva collection methods for DNA biomarker analysis in oral cancer patients

Patients with head and neck cancers are predisposed to local recurrence and second primaries because of the phenomenon of field cancerisation, and clinical detection of recurrence remains challenging. DNA biomarkers in saliva may prove to be an adjunct to current diagnostic methods, but irradiation of the primary site often leads to xerostomia. We assessed 3 methods of collecting saliva for their ability to generate DNA of sufficient quantity and quality to use in biomarker assays. Paired saliva samples were collected from 2 groups of patients with oral squamous cell carcinoma (SCC). In the first group saliva was collected in Oragene^® vials and as saline mouthwash from non-irradiated patients (n = 21) (4 had had radiotherapy before collection); in the second group it was collected using Oragene^® sponge kits and as mouthwash from irradiated patients (n = 24). Quantitative polymerase chain reaction (qPCR) showed that Oragene^® vials contained DNA in significantly greater amounts (median 122 μg, range 4–379) than mouthwash (median 17 μg, range 2–194) (p = 0.0001) in the non-irradiated patients, while Oragene^® sponge kits (median 4 μg, range 0.1–61) and mouthwash (median 5.5 μg, range 0.1–75) generated comparable concentrations of DNA from the irradiated group. All 90 samples contained DNA of sufficient quantity and quality for p16 promoter quantitative methylation-specific PCR (qMSP). While Oragene^® vials contained the most DNA, all 3 methods yielded enough to detect DNA biomarkers using qMSP. The method of collection should depend on the compliance of the patient and oral competency.     

Probiotic intervention influences the salivary levels of Matrix Metalloproteinase (MMP)-9 and Tissue Inhibitor of metalloproteinases (TIMP)-1 in healthy adults

ObjectiveTo study the effect of orally administered Bifidobacterium animalis subsp. lactis BB-12 and Lactobacillus rhamnosus GG on the salivary levels of Matrix Metalloproteinases (MMP)-8, MMP-9 and of Tissue Inhibitor of Metalloproteinases (TIMP)-1 in healthy adults. Furthermore, the correlations between MMP-8, MMP-9 and TIMP-1 and plaque and gingival indices, salivary mutans streptococci and lactobacilli counts, and stimulated saliva secretion rate were analysed.DesignThe salivary samples originated from a randomized controlled trial where healthy student volunteers consumed probiotic or placebo lozenges twice a day for four weeks. The saliva samples were collected and clinical parameters measured at the baseline and at the end of the original study. For this study, the salivary levels of MMP-8, MMP-9 and TIMP-1 were analysed with immunofluorometric assay (IFMA) and enzyme-linked immunosorbent assay (ELISA).ResultsIn the probiotic group (n = 29), salivary MMP-9 levels increased (p < 0.01) and TIMP-1 levels decreased (p < 0.01) significantly during the intervention. Furthermore, MMP-9/TIMP-1 ratio differed significantly from the baseline level (p < 0.01). These changes were not observed in the control group (n = 31). In the whole data, salivary MMP-9 and gingival index correlated (r = 0.260, p < 0.05 at baseline and r = 0.354, p < 0.01 at the end of the study). Intergroup differences or correlations with other clinical parameters were not found. Probiotic consumption did not affect the saliva flow rate.ConclusionsIncreased MMP-9 and decreased TIMP-1 levels in saliva may indicate that probiotics have immunomodulatory effects in the oral cavity. Furthermore, increased salivary MMP-9 levels may be an indication of the defensive potential of matrix metalloproteinases.     

Stability of miniscrews with different continuous orthodontic forces as measured by cone-beam computed tomography

PurposeMiniscrew stability is a key for successful orthodontic anchorage reinforcement. Light force as 50 g has been proposed to efficiently retract canine; however, for miniscrew stability, its efficiency is still questionable. This study aimed to evaluate and compare miniscrew displacements loaded with 50 and 150 g to retract upper canines.Subjects and methodsTwenty four miniscrews (1.4 mm diameter and 7 mm length) were placed in twelve orthodontic patients (female, 22.55 ± 4.8 years old) who required miniscrews for maximum anchorage. Cone-beam computed tomography (CBCT) was taken to assess the miniscrew displacement in three dimensions. The X, Y, Z coordination points at the miniscrew head and tail with anterior nasal spine as a reference point were recorded and analyzed the displacements during 3 months using one-sample t-test and pair t-test.ResultsMiniscrews were significantly displaced after loading 50 and 150 g at 2 and 3 months compared to baseline (P < 0.001). At 2 months, the displacement of the miniscrews at head and tail had no statistical significance between 50 and 150 g (P > 0.05). However, at 3 months, there were statistically significant displacements between 50 and 150 g. This displacement was found to be greater in 150 g and at head more than at tail (P < 0.05).ConclusionThis study concluded that miniscrews could be significantly displaced with 50 and 150 g during 3 months wherein the heavier loading force essentially caused more miniscrew mobility. Clinically, it is suggested to use proper magnitude of force to miniscrews with care in order to overcome orthodontic anchorage failure.     

Possible implications of Ni(II) on oral IL-1β-induced inflammatory processes

ObjectivesNickel (Ni) is one of the main metal elements in orthodontic and prosthetic devices. Different effects of Ni are described ranging from an induction of local inflammation to allergy and cancerous/mutagenic properties. Inflammatory reactions are frequently observed in the oral cavity, but the interrelationship of Ni with those events is still unknown. Therefore, we focused on the impact of Ni on inflammation in vitro.MethodsIn accordance to previous immersion tests of our lab, human gingival fibroblasts (HGFs) (n = 6) were exposed to a pro-inflammatory environment using interleukin-1 beta (IL-1β) and additionally stimulated with different Ni(II) concentrations (400 and 4000 ng/ml). At varying time points the expression of pro- and anti-inflammatory as well as matrix degeneration proteins, i.e. MMPs, were analyzed. Furthermore, proliferation assays, wound healing tests and the detection of NF-κB activation were conducted. Unstimulated HGFs served as control.ResultsOur experiments showed that low clinical average Ni(II) levels did not alter pro-inflammatory cytokines significantly compared to control (p > 0.05). Instead, a 10-fold higher dose up-regulated these mediators significantly in a time-dependent manner (p < 0.01). This was even more pronounced combining both Ni(II) concentrations with an inflammatory condition (p < 0.001), MMP expressions were in line with our findings (p < 0.001). The mRNA data were supported by proliferation and wound closure assays (p < 0.001). However, the combination of both stimuli induced contradictory results. Analyzing NF-κB activation revealed that our results may be in part attributed to NF-κB.SignificanceOur in vitro study implicated that Ni(II) has various modifying effects on IL-1β-induced inflammatory processes depending on the concentration.     

Laser surface treatment to improve mechanical properties of cast titanium

ObjectiveThe aim of this study was to investigate the effect of laser surface treatment on the mechanical properties of cast titanium and to compare with those of the Co–Cr alloy.MethodsDumbbell-shaped cast specimens were prepared for commercially pure titanium (grade 2) and Co–Cr alloy. The cast titanium specimens were laser-treated on the surface using a dental Nd:YAG laser machine at 240 V and 300 V. After laser treatment, tensile testing was conducted to obtain the tensile strength, percent elongation and modulus of elasticity. The hardness depth profile was made from the cast subsurface (25 μm) to 1500 μm in depth using the cross-sections of the cast rods with the same diameter as the dumbbell. The data were statistically analyzed by ANOVA/post hoc tests (p < 0.05).ResultsThe highest tensile strength was obtained for the titanium specimens laser-treated with 300 V followed by the 240 V and the control specimens. The laser-treated titanium specimens with 300 V showed a tensile strength equivalent to the Co–Cr alloy. Although the highest modulus of elasticity was found for the specimens laser-treated with 240 V, there were no significant differences in elastic modulus among 240 V, 300 V and Co–Cr. The laser-treated groups showed significantly lower hardness at the subsurface of 25 μm and maintained their hardness until the depth of 400 μm. The hardness of the control group was very high at 25 μm depth, and dramatically decreased until the 200 μm depth.ConclusionThe results of tensile testing and hardness depth-profiling indicated that the laser treatment significantly improved the mechanical properties of cast titanium by improving the surface integrity of the cast surface contamination.     

Early tissue reaction in the tension zone of PDL during orthodontic tooth movement

ObjectiveThe aim of the study was to examine the early tissue reaction in the tension zone of periodontal ligament (PDL) during orthodontic tooth movement.DesignUpper first molars of rats were moved buccally with fixed appliances. The PDL in the tension zone was examined histologically, immunohistochemically and at a molecular level after 24 h, 3 days and 7 days.ResultsAfter 24 h of orthodontic force loading, the periodontal space appeared considerably expanded. The periodontal fibers were stretched between the bone and the root. Three days after loading, the expanded periodontal space had slightly narrowed, the periodontal fiber arrangement was relaxed, and the blood vessels did not appear elongated. A considerable layer of osteoid was formed on the bone surface.The total cross-sectional areas of the PDL in experimental groups were significantly larger than control group. The total cross-sectional areas of the blood vessels were not significantly different among the groups.Significantly high expressions of IL-1β and PTX3 were characteristically observed not only in the endothelial cells and cells around the blood vessel, but also in fibroblasts throughout the PDL of the tension zone 24 h after orthodontic force loading. Three and 7 days after loading, these showed tendencies to return to control levels.ConclusionsThe present results suggest that the early reaction in the tension zone of the PDL during tooth movement consists of two phases: first, inflammation and second, rapid recovery and renovation of the PDL with bone formation.     

Evaluation of physical properties of fiber-reinforced composite resin

ObjectivesThis study aimed to investigate physical properties of a fiber-reinforced CAD/CAM resin disc, which included woven layers of multi-directional glass fibers.MethodsFiber orientations of CAD/CAM specimens (TRINIA, SHOFU) were specified as longitudinal (L), longitudinal-rotated (LR), and anti-longitudinal (AL). A fiber-reinforced composite (everX posterior, GC (E)) and a conventional composite (Beauti core flow paste, SHOFU (B)) were also tested.A three-point bending test and a tensile test with notchless prism-shaped specimens were conducted using a universal testing machine (AUTOGRAPH AG-IS, Shimadzu). A water absorption test was also carried out after the specimens were stored in water for 24 h or 1 week. Flexural strength and fracture toughness were obtained by conducting a three-point bending test.ResultsTRINIA L and LR groups showed significantly high flexural strength (254.2 ± 22.3 and 248.8 ± 16.7 MPa, respectively). Those were approximately 2.5 times higher than those in AL, E, and B groups (96.8–98.0 MPa) (p < 0.05, ANOVA and Tukey HSD test). No significant difference was shown in flexural modulus among the experimental groups. The fracture toughness in L group (9.1 ± 0.4 MPa/m^1/2) was found to be significantly higher than those in other groups (1.9–3.0 MPa/m^1/2; p < 0.05). TRINIA group demonstrated significantly lower water absorption (4.7 ± 1.9 μg/mm³) than did E (16.1 ± 3.1 μg/mm³) and B (17.3 ± 3.7 μg/mm³) groups (p < 0.05).SignificanceTRINIA demonstrated distinct anisotropy. TRINIA can be used as a superior restorative material when specifying directions of its fiber mesh layers.     

Initial bone regeneration around fenestrated implants in Beagle dogs using basic fibroblast growth factor–gelatin hydrogel complex with varying biodegradation rates

PurposeThe purpose of this study was to compare the effectiveness of fast and slow biodegradation of basic fibroblast growth factor (bFGF)–gelatin hydrogel complex on bone regeneration around fenestrated implants as a new augmentation drug delivery system.MethodsNine titanium implants (3.3 mm diameter and 10 mm length) were placed into the edentulous areas of the mandibles of three adult beagle dogs with four screws exposed at the upper buccal side. The effectiveness of bFGF–gelatin hydrogel complexes of varying degradation types used to cover implant screws without membrane were compared with 1 μg and 10 μg bFGF–98 wt% gelatin as the fast degradation type and 10 μg bFGF–95 wt% gelatin as the slow degradation type. After 4 weeks, bone regeneration around the screws was evaluated histologically and histomorphometrically.ResultsWith use of 10 μg bFGF, regenerated bone around exposed screws was clearly seen in both the fast and slow degradation type groups. In contrast, little bone formation was seen in the fast degradation-type group with 1 μg bFGF. Height of regenerated bone for the slow degradation-type complex group was significantly greater than for the fast degradation-type group with 1 μg bFGF (P < 0.05).ConclusionThese results suggest that use of slow degradation-type bFGF–gelatin hydrogel complex may accelerate bone regeneration around fenestrated implants at an early stage of bone regeneration.     

Salivary levels of calcium,phosphorus, potassium,albumin and correlation with serum biomarkers in hemodialysis patients

ObjectivesEvidences suggest that hemodialysis patients have reduced salivary flow and changes in the composition of salivary secretion. These changes may reflect local and systemic disorders. The objectives of this study were to compare the salivary levels of calcium (Ca), phosphorus (P), potassium (K) and albumin in hemodialysis patients and healthy subjects, and to investigate a possible correlation between their serum and salivary levels.DesignA case–control study was conducted with 60 hemodialysis patients (HD group) and 37 systemically healthy individuals (control group). Stimulated saliva samples were collected for biochemical analysis (Ca, P, K and albumin). Serum data were collected in the HD group. Statistical analysis included t-test, Pearson correlation and simple linear regression.ResultsThe HD group exhibited higher salivary levels of Ca, P, and albumin (p < 0.05). There was a significant positive correlation between serum PTH and salivary phosphorus (r = 0.342, p = 0.009), and between serum PTH and salivary potassium (r = 0.306, p = 0.020). An increase of 100 pg/dL in serum PTH was associated with an elevation of salivary P levels (0.34 mg/dL, p = 0.009), and salivary K levels (0.20 mmol/dL, p = 0.02), in the HD group.ConclusionsThe findings suggest that HD patients present increased levels of salivary components (Ca, P, and albumin), and changes commonly observed in HD patients, such as hyperparathyroidism, appear to have an influence on salivary composition.     

Effect of honey in preventing gingivitis and dental caries in patients undergoing orthodontic treatment

ObjectivesThis study was conducted to investigate the following: (1) the effects of chewing honey on plaque formation in orthodontic patients, (2) the effect of chewing honey on dental plaque bacterial counts, (3) determine if honey possesses antibacterial effects on bacteria recovered from plaques.MethodsFemale orthodontic patients (n = 20, 12–18 years of age) participated in this randomized controlled study. The effects of honey were compared to treatment with either 10% sucrose or 10% sorbitol that served as positive and negative controls, respectively. The pH of plaque was measured using a digital pH meter prior to baseline and at 2, 5, 10, 20, and 30 min after chewing honey or rinsing with control solutions and the numbers of Streptococcus mutans, Lactobacilli, and Prophymonas gingivalis in respective plaques were determined. The antibacterial activity of honey was tested against commonly used antibiotics using the disk diffusion method.ResultsSignificant differences in pH were observed in the honey and sucrose groups compared to the pH observed in the sorbitol group (p ? 0.001). The maximum pH drop occurred at 5 min in both the honey and sucrose groups; however the pH in the honey group rapidly recovered 10–20 min after exposure and did not drop below the critical decalcification pH of 5.5. On the other hand, the pH following sucrose exposure fell <5.5 and was associated with a 30 min recovery time. The pH observed for the sorbitol group did not change over time. Bacterial counts were significantly reduced in the honey group compared to the other treatment groups (p ? 0.001) and honey significantly inhibited the growth of all studied strains compared to inhibition observed with antibiotics (p ? 0.001).ConclusionsHoney can be used as an alternative to traditional remedies for the prevention of dental caries and gingivitis following orthodontic treatment.     

The effect of initial periodontal treatment on plasma,gingival crevicular fluid and salivary levels of 8-hydroxy-deoxyguanosine in obesity

ObjectiveRecent studies have shown adverse effects on the periodontium from the increased production of reactive oxygen species (ROS) in obesity. The purpose of this study was to investigate the effects of obesity on 8-hydroxy-deoxyguanosine (8-OHdG) levels in the bodily fluids of patients with and without periodontal disease and to evaluate changes after initial periodontal treatment.DesignForty-five obese individuals and 45 normal-weight individuals were included in this study. Obese and normal-weight groups were classified into three sub-groups: chronic periodontitis (CP), gingivitis (G) and periodontally healthy controls (CTRL). Gingival crevicular fluid (GCF), plasma, saliva samples and clinical measurements were obtained at baseline and a month after initial periodontal treatment. Levels of 8-OHdG were analysed by ELISA.ResultsWhile plasma 8-OHdG levels were significantly higher at baseline in the obese patients with periodontal disease than in the normal-weight individuals (P < 0.05), no significant differences in GCF and saliva 8-OHdG levels were found (P ˃ 0.05). GCF and salivary 8-OHdG levels in obese patients with G and CP were significantly higher than in CTRL groups at baseline (P < 0.05). After treatment, 8-OHdG levels were decreased in all groups with periodontal disease (P < 0.01). Statistically significant positive correlations were observed between GCF 8-OHdG levels and GI in all the groups (P < 0.001).ConclusionsThe significant increase of plasma 8-OHdG levels in obese patients did not correlate with saliva and GCF 8-OHdG levels when compared to normal-weight individuals. Periodontal treatment had a positive effect on the periodontal parameters and 8-OHdG levels of both obese and normal-weight individuals.