Is serum BDNF level reliable parameter in detecting of dental anxiety before impacted third molar surgery?

BACKGROUND: Brain-derived neurotrophic factor (BDNF) is a factor that implicate in the pathophysiology and treatment of depression and anxiety. The aim of this study was to determine the relationship between dental anxiety and BDNF serum level through impacted third molar surgery. MATERIAL AND METHODS: In this randomized, double-blind, cross-sectional study, the sample included patients who had been admitted for the impacted third molar extraction under local anesthesia between January to November 2020. The primary predictor variable was serum BDNF level and the second predictor variable was dental anxiety scores before and after operation in patients. The primary outcome variable was the correlation between anxiety scores (APAIS, MDAS, STAI, VAS) and serum BDNF level. The sample included 55 patients (22 Male, 33 Female) aged 18 to 42 (24,2+5,55). RESULTS: Comparison of pre-operative scores (APAIS, MDAS, STAI, VAS and BDNF) and post-operative scores were statistically significant (P < .05). Post-operatively, MDAS and VAS scores decreased, while BDNF levels and STAI scores increased compared to the preoperative scores. BDNF was not correlated with APAIS, MDAS, STAI, and VAS preoperatively and postoperatively. CONCLUSIONS: There may be a relationship between serum BDNF level and dental anxiety scale, but, no correlation was found between them.

Relationship between obesity and prevalence of dental anomalies: Does body mass index play a role?

AIM: The aim of this study was to investigate the prevalence of dental anomalies in different body mass index (BMI) percentile child and adolescent subjects. MATERIALS AND METHODS: Panoramic radiographs of 186 subjects (68 males and 118 females) were evaluated. The subjects were divided into three groups according to BMI percentile: Normal-weight (93), overweight (40), and obese (43) subjects. Supernumerary tooth, tooth agenesis, dens invaginatus, dens evaginatus, tooth impaction, taurodontism, pulp stone, and root dilaceration were assessed. RESULTS: Root dilaceration was found in 11.3% of the obese subjects and 17.5% of the overweight subjects. There was a statistically significant difference in the root dilaceration prevalence among the groups (p=0.015). However, other dental anomalies did not display statistically significant differences among the groups (p>0.05). While there was no statistically significant difference in the dental anomalies prevalence among different BMI percentile groups in males (p>0.05), a statistically significant difference in the root dilaceration prevalence was detected among different BMI percentile groups in females (p=0.036). The data were analysed using chi-square and Fisher's exact tests. CONCLUSION: The prevalence of root dilaceration was significantly greater in obese and overweight subjects than in normal-weight subjects.

Downregulation of the α1- and ß1-subunit of sGC in Arterial Smooth Muscle Cells of OPSCC Is HPV-Independent.

The nitric oxide (NO)-sensitive soluble guanylyl cyclase (sGC) is a heterodimeric enzyme with an α and ß subunit. NO binds to heme of the ß1-subunit of sGC, activates the enzyme in the reduced heme iron state in vascular smooth muscle cells (VSMCs), and generates cGMP-inducing vasodilatation and suppression of VSMC proliferation. In the complex tumor milieu with higher levels of reactive oxygen species (ROS), sGC heme iron may become oxidized and insensitive to NO. To change sGC from an NO-insensitive to NO-sensitive state or NO-independent manner, protein expression of sGC in VSMC is required. Whether sGCα1ß1 exists at the protein level in arterial VSMCs of oropharyngeal squamous cell carcinoma (OPSCC) is unknown. In addition, whether differences in the genetic profile between human papillomavirus (HPV)-positive and HPV-negative OPSCC contributes to the regulation of sGCα1ß1 is unclear. Therefore, we compared the effects of HPV-positive and HPV-negative OPSCC on the expression of sGCα1ß1 in arterial VSMCs from tumor-free and tumor-containing regions of human tissue sections using quantitative immunohistochemistry. In comparison to the tumor-free region, we found a decrease in expression of both α1- and ß1-subunits in the arterial VSMC layer of the tumor-containing areas. The OPSCC-induced significant downregulation of the α1- and ß1-subunits of sGC in arterial VSMC was HPV-independent. We conclude that the response of sGC to NO in tumor arterial VSMCs may be impaired by oxidation of the heme of the ß1-subunit, and thus, α1- and ß1-subunits of sGC could be targeted to degradation under oxidative stress in OPSCC in an HPV-independent manner. The degradation of sGCα1ß1 in VSMCs may result in increased proliferation of VSMCs, promoting tumor arteriogenesis in OPSCC. This can be interrupted by preserving the active heterodimer sGCα1ß1 in arterial VSMCs.

The effects of ozone application on genotoxic damage and wound healing in bisphosphonate-applied human gingival fibroblast cells.

OBJECTIVES: Medication-related osteonecrosis of the jaws (MRONJ) is an extremely therapy-resistant disease involving the jaws especially following bisphosphonate treatment. Bisphosphonates accumulate in bone in concentrations sufficient to be directly toxic to the oral epithelium. Current therapeutic options are inadequate for the prevention and treatment of MRONJ. The aim of this study was to investigate effects of ozone gas plasma therapy on wound healing in bisphosphonate-applied human fibroblasts. MATERIAL AND METHODS: Human primary gingival fibroblasts were cultured. Cytotoxic concentrations (IC50) of bisphosphonates (pamidronate (PAM), alendronate (ALN), and zoledronate (ZOL)) were determined by MTT test. A 60 µg/µl for 30 s of ozone gas plasma application was performed to all experimental culture flasks after drug treatment at 24-h intervals as 3 s/cm2. Genotoxic damages were evaluated by comet assay and wound healing was determined by in vitro scratch assay. RESULTS: PAM, ALN, and ZOL applications caused genotoxic damage on primary human gingival fibroblast DNA. Ozone gas plasma therapy significantly decreased the genotoxic damage (p < 0.05), and this application provided 25, 29, and 27% less genotoxic damage in order of ALN, PAM, and ZOL groups. Ozone gas plasma therapy significantly increased wound healing rates both in postsurgical 24th and 48th hours for all doses of experimental drug groups (p < 0.05). CONCLUSION: The ozone gas plasma application decreased genotoxic damage effect of bisphosphonate usage while improved the wound closure rate on human gingival fibroblasts. CLINICAL RELEVANCE: Ozone gas plasma therapy may be helpful in prevention of gingival healing delay in MRONJ pathogenesis especially when applied simultaneously with surgical intervention.

Does additional cone beam computed tomography decrease the risk of inferior alveolar nerve injury in high-risk cases undergoing third molar surgery?Does CBCT decrease the risk of IAN injury?

The objectives of this study were to evaluate the efficacy of additional cone beam computed tomography (CBCT) imaging on decreasing the risk of inferior alveolar nerve (IAN) injury during third molar removal in patients at high risk and to assess the surgical outcomes. The study sample included patients considered at high risk for IAN injury based on panoramic radiography (PAN) evaluation. The primary predictor was the type of imaging method (PAN only or with additional CBCT). The other variables were demographic and anatomical/radiographic factors. The primary outcome variable was IAN injury. The secondary outcome variables were the preoperative surgical plan and surgical results including IAN exposure and duration of surgery. The sample comprised 122 patients (139 teeth) aged 18-48 years. Postoperative temporary IAN injury was present in three (4.2%) cases in the CBCT group and 11 (16.4%) in the PAN group at 7 days after surgery. However, none of the patients had a permanent IAN injury at the 6-month follow-up. Additional CBCT imaging was not superior to PAN in reducing IAN injury after third molar surgery during long-term follow-up. Nonetheless, CBCT may decrease the prevalence of temporary IAN injury and improve the surgical outcomes in high-risk patients.

Dentists' knowledge of occlusal splint therapy for bruxism and temporomandibular joint disorders.

AIMS: The aim of this study was to investigate dentist's approaches to the use of splint therapy for myofascial pain, bruxism, and temporomandibular joint (TMJ) disorders and to assessment of treatment modalities. MATERIALS AND METHODS: A 12-item questionnaire was developed to determine dentists' knowledge of TMJ disorders and approaches for occlusal splint treatments. The researchers spoke with each dentist included in the study at his/her clinic or by telephone to assess their immediate knowledge and approach to the TMJ disorders. Chi-squared test was performed to analyze the values. The confidence interval was set as 95%. RESULTS: A total of 370 dentists working in Turkey were participated in this study. The most common splint application reason for occlusal splint treatment was bruxism (77.8%) while TMJ pain was very rare (%1.4). The use of hard splint ratios for 0-5 years of professional experience was 57.0%, 42.4.0%, and 26.8% for the experience of 5-15 years and over 15 years groups, respectively (P < 0.001). While the dentists' with sufficient knowledge soft splint application rates were 11.6%, hard splint application rates were 43.4% for the dentists with sufficient knowledge. Occlusion adjustment rate of dentists who practice in all three groups was under 16.0%. CONCLUSIONS: The knowledge of the dentists about TMJ disorders and occlusal splint therapy were found to be insufficient. Their knowledge decreased with increasing experience.

Chemical analysis of enamel and dentin following the application of three different at-home bleaching systems.

PURPOSE: To determine the change in the chemical composition of enamel and dentin as well as to evaluate the differences in surface texture of the same dental hard tissues following three at-home bleaching systems in vitro. METHODS: Sixty extracted intact human anterior teeth were used in this study. Thirty teeth were used as samples for enamel, and the buccal surfaces of the remaining 30 teeth were abraded and used as dentin samples. Prior to bleaching treatments, calcium (Ca), phosphorus (P), potassium (K), sodium (Na), magnesium (Mg), fluoride (F), and oxygen (O) levels of each sample were measured using an energy dispersive spectrometer. The teeth were then randomly allocated into three groups according to the bleaching system used, as follows: GI, 10% carbamide peroxide (CP); GII, 20% CP; GIII, and 35% CP. Following the bleaching treatments, Ca, P, K, Na, Mg, F, and O measurements were repeated. The surface configurations were examined using scanning electron microscopy (SEM). The data were analyzed using Wilcoxon signed rank and Kruskal-Wallis tests followed by the Dunn test. RESULTS: All three bleaching systems tested caused similar changes in the chemical composition of enamel and dentin. Bleaching systems decreased Ca and K, while F and O levels increased in enamel. In dentin, Ca, P, and K levels decreased; however, Na, F, and O levels increased. SEM observations revealed no deleterious effect on enamel and dentin. CONCLUSION: The use of home bleaching agents could affect the chemical composition of dental hard tissues, whereas the change in the chemical composition of enamel and dentin was not affected by the CP concentration of the bleaching systems used.

Irreversible inflammation is associated with decreased levels of the alpha1-, beta1-, and alpha2-subunits of sGC in human odontoblasts.

The nitric oxide (NO) receptor enzyme soluble guanylate cyclase (sGC) contains one prosthetic heme group as an αß heterodimer, and two heterodimer isoforms (α(1)ß(1), α(2)ß(1)) were characterized to have enzyme activity. To test the irreversible inflammation-dependent regulation of sGC in odontoblasts, we incubated decalcified frozen sections of healthy and inflamed human third molars with antibodies against ß-actin, nitrotyrosine, inducible nitric oxide synthase (iNOS), α(1)-, ß(1)-, and α(2)-subunits of sGC and analyzed them at protein levels by quantitative immunohistochemistry. The irreversible inflammation induced an increase in the signal intensities for nitrotyrosine and iNOS and a decrease for the α(1)-, ß(1)-, and α(2)-subunits of sGC in odontoblasts. Inflammatory mediators, reactive oxygen, and nitrogen species may impair the expression of the α(1)-, ß(1)-, and α(2)-subunits in odontoblasts. The decrease of sGC at the protein level in inflamed odontoblasts is compatible with a critical role for sGC to mediate biological effects of NO in health.

Effect of adhesive system type and root region on the push-out bond strength of glass-fibre posts to radicular dentine.

AIM: To compare interfacial strength in different thirds of the root canal amongst glass-fibre posts luted with four different adhesive luting agents. METHODOLOGY: A total of 44 extracted human single-rooted teeth were randomly divided in four groups and restored using glass-fibre posts and the following luting agents: All Bond SE/Duo-Link (ABSE), All Bond 3/Duo-Link (AB3), BisCem (BC), Clearfil ED primer II/Clearfil Esthetic Cement (CLF). One week after luting, the samples were thermocycled in water, and then embedded in acrylic resin. Three sections (cervical, middle and apical) of 2 mm thickness were prepared from each specimen, and the post in each section was subjected to a push-out test. One additional specimen for each group was prepared for scanning electron microscopy analysis and the bonding effectiveness to dentine was assessed. The data were analysed using the Kolmogorov-Smirnov test, two-way anova, one-way anova, and the Scheffe test (P < 0.05). RESULTS: The push-out bond strength values for BC and ABSE were not significantly different (P > 0.05), but both were significantly higher than the means for AB3 and CLF (P < 0.05) in the cervical and middle regions. The same trend was observed in the apical region, except for the AB3 and ABSE which were not significantly different (P > 0.05) from each other. There were significant differences in bond strength amongst root thirds, with a reduction in values from the cervical to apical third (P < 0.05). CONCLUSIONS: The use of BisCem and All Bond SE/Duo-Link combination with their simplified application procedures may be considered an alternative to the currently used systems for luting glass-fibre posts in root canal.

Time-dependent activation of ERK1/2 in nerve terminals of the dentin-pulp complex following bradykinin treatment.

The extracellular signal-regulated kinases 1 and 2 (ERK1/2) have been implicated in the inflammation-dependent sensitization of nociceptors, and the inflammatory mediator bradykinin (BK) led to a reduced threshold in the nociceptor terminals, activating intracellular signaling by phosphorylating receptors and ion channels. The effects of BK on the non-transcriptional modulation of the ERK1/2 in the peripheral nociceptor terminals, including in nerve endings of the dentin-pulp complex, are unknown. The time-dependent effects of BK (10(-7) M) on the ERK1/2 phosphorylation in nerve terminals of the dentin-pulp complex were investigated by quantitative and double immunolabeling with organ bath experiments. In nerve terminals, total and p-ERK1/2 were detected. In comparison with the controls, the numbers of p-ERK1/2-positive nerve endings increased after 1 and 3 min and decreased after 10 min of BK treatment. Analysis of the data indicates that BK induces phosphorylation-mediated local activation of ERK1/2 in nerve terminals modulating nociception in the dentin-pulp complex.

Healing of onlay mandibular bone grafts covered with collagen membrane or bovine bone substitutes: a microscopical and immunohistochemical study in the sheep.

The objective of this study was to evaluate the role of collagen membrane and Bio-Oss coverage in healing of an onlay graft to the mandible. Twelve adult sheep each received an onlay bone graft (experiment 1), bone graft+Bio-Gide (experiment 2), and bone graft+Bio-Oss/Bio-Gide (experiment 3) on the lateral surface of the mandible. The animals were euthanized at 4, 8, 12 or 16 weeks after surgery, and findings were analysed by routine microscopy and immunohistochemistry for proliferation (Ki67) and apoptotic (Caspase-3) markers. Grafts were fully incorporated in all specimens. Pronounced resorption was observed in experiment 1. Minimal loss of graft volume was seen in experiment 2 specimens without membrane displacement. A remarkable increase in the augmented region of the mandible was observed in experiment 3. A high number of osteoclasts were expressed within the grafts during the early healing period, and thereafter declined markedly. Osteoblasts within the grafts expressed a moderate level of Ki67 at 8 weeks, which thereafter declined markedly. The strongest expression of Caspase-3 on the bone surface was observed after 16 weeks. In conclusion, the effect of collagen membrane coverage on bone graft volume maintenance was dependent on membrane stability during healing. An autogenous bone graft covered with Bio-Oss particles resulted in a remarkable increase in augmented lateral surface of the mandible. The late stage of bone graft healing was associated with a high apoptotic induction pathway of osteoblasts lining the surfaces of the new bone, demonstrated by strong positive Caspase-3 immunoreactivity.

Bradykinin mediates phosphorylation of eNOS in odontoblasts.

While the activation of eNOS by Akt/PKB-dependent phosphorylation, leading to NO release, and the inhibition of enzyme activity by bradykinin (BK)-mediated phosphorylation of eNOS in endothelial cells are established, the phosphorylation of eNOS in odontoblasts is unknown. To clarify the regulation of eNOS in odontoblasts by BK, we examined the phosphorylation of eNOS, Akt/PKB, and ERK1/2 in odontoblasts of rat molars. BK (10(-7) M) transiently induced the phosphorylation of eNOS at Ser1177, Akt/PKB in odontoblasts, while it induced the phosphorylation of eNOS at Thr495 throughout the entire period of BK treatment. BK receptor 2 antagonist HOE 140 (10(-6) M) significantly reduced signal intensities of phosphorylated-eNOS at Ser1177, Thr495, and phosphorylated-Akt/PKB. These results suggest that BK has dual effects on the activation of eNOS in odontoblasts, the Akt/PKB-dependent up-regulation of eNOS by the transient phosphorylation at Ser1177, and the ERK1/2-independent down-regulation of eNOS by the phosphorylation at Thr495.

Impact of endodontic treatments on the rigidity of the root.

The destabilizing effect of endodontic treatment upon teeth is still controversial. The purpose of this study was to investigate the effects of different steps of endodontic treatments upon the rigidity of teeth. Extracted untreated central maxillary anterior teeth were loaded (3.75 N), and deformations of the root were assessed by Speckle pattern interferometry. The following treatments (with subsequent determination of deformability) were conducted sequentially: access preparation, manual instrumentation (Kerr files ISO-40, ISO-60, ISO-80, ISO-110), and tapered and parallel-sided post preparation. It was found that the teeth were increasingly destabilized by any treatment. While the increased deformability was not significant with the manual enlargement (p > 0.05), we found a significant destabilization after access preparation and post preparation (p < 0.05). A corresponding difference was found after conversion of the post preparation from tapered to parallel-sided (p < 0.05). Both substance loss and modifications of the natural root canal geometry play an important role in tooth rigidity.

Sealant and composite bond strength to enamel with antibacterial/self-etching adhesives.

INTRODUCTION: The enamel in pits and fissures undergoing preventive or ultraconservative resin restorations may be affected by secondary caries. An antibacterial adhesive bond may be a useful choice to prevent and reduce demineralization. OBJECTIVES: The purpose of this study was to determine the shear bond strength of an experimental antibacterial bond, a self-etch bond, and an ormocer-based adhesive bond using an ormocer-based fissure sealant and a composite resin on intact enamel. METHODS: Twenty-four extracted human molars were sectioned bucco-lingually to obtain two flat and sound enamel surfaces. Forty-eight specimens were randomly assigned into four groups. The groups were prepared to receive the following treatments: (1) Admira Bond + Admira Seal (n = 10); (2) ABF Bond + Admira Seal (n = 11); (3) Clearfil SE Bond + Clearfil AP-X (n = 12); and (4) ABF Bond + Clearfil AP-X (n = 11). A cylindrical mould was placed over the bonded surface, and both materials were applied according to the instructions. The teeth were thermocycled 500 cycles between 5 and 55 degrees with a dwell time of 30 s. For shear bond strength testing, the load was applied vertically to the base of the mould. The cross-head speed was 5 mm min(-1). RESULTS: The maximum load that a specimen can withstand until failure was determined and shear bond strength was calculated by dividing the load at failure by the surface area of the mould. The results (median, minimum and maximum, respectively) for the four groups were: (1) 7.9, 4.2 and 13.6 MPa; (2) 8.6, 2.6 and 15.9 MPa; (3) 5.9, 5.3 and 8.2 MPa; and (4) 8.8, 3.0 and 19.2 MPa. Kruskal-Wallis and Mann-Whitney U-tests were performed for the statistical analysis. Groups 3 and 4 were statistically significantly different (P = 0.005; P < 0.05). There was no statistically significant difference between the sealant and composite groups for ABF (P = 0.375). Fracture sites were viewed by microscope under x 16 magnification to determine if the mode of failure was adhesive or cohesive. The results (number of adhesive failed specimens and number of cohesive failed specimens, respectively) for the four groups were: (1) 7 and 3; (2) 3 and 8; (3) 2 and 9; and (4) 8 and 3. CONCLUSION: The ABF bond has sufficiently physical qualities to be used under fissure sealant and composite resin on uncut enamel, its antibacterial efficiency notwithstanding.

NO-cGMP signaling molecules in cells of the rat molar dentin-pulp complex.

By the formation of cyclic guanosine 3',5'-monophosphate (cGMP), nitric oxide (NO)-sensitive enzyme-soluble guanylate cyclase (sGC) plays a receptor role for NO within the NO-cGMP signaling cascade, which is involved in vasodilatation and neurotransmission. The hypothesis that NO-cGMP signaling molecules modulate cells of the dentin-pulp complex was investigated in rat molars by histochemical, immunohistochemical, immuno-ultrastructural, and organ bath techniques. NO synthase (NOS) I-III, the sGC alpha(2)-subunit/beta(1)-subunit, and cGMP were detected in odontoblasts and blood vessels. NOS I, sGC alpha(2), and cGMP were identified in nerve fibers. Treatment of rat molars with the NO donor NONOate (10(-5) M) increased cGMP staining intensities in blood vessels and odontoblasts, while NO synthase inhibitor L-NAME (10(-4) M) attenuated intensity of the reaction products for cGMP, suggesting an effect of endogenous NO on sGC. These correlations of patterns and alterations of cGMP staining intensities after treatment with the NO donor or NO inhibitor might represent an NO-sGC-cGMP signaling-dependent modulation of odontoblasts, blood vessels, and nerve fibers in the dentin-pulp complex.