The self-perceived competency of dental students about contagious diseases during the COVID-19 pandemic and its effect on their career plans.

BACKGROUND: Dentistry is reported as a very-high-risk profession for COVID-19 contagion. A lack of face-to-face education and poor information during the COVID-19 pandemic may have impacted dental students. OBJECTIVES: We aimed to evaluate the effects of the COVID-19 pandemic on career plans and self-perception of knowledge levels in undergraduate dental students. MATERIAL AND METHODS: In this multicenter cross-sectional study, a multiple-choice survey was completed by dental students of Near East University (NEU) in North Nicosia and University of Kyrenia (UoK) in the Turkish Republic of Northern Cyprus (TRNC), and Erciyes University (ERU) in Kayseri, Turkey, in 2020. The χ2 tests were used to determine statistically significant differences. RESULTS: Of the 755 students that participated in the study, 66% declared fear of being at risk for contagion. More than half of the students reported not having sufficient knowledge about occupational infections and methods for protection, and the percentages were significantly higher in female and preclinical students. Utilization of credible publications, guidelines (57% compared to 34%, p < 0.001) and online education (19% compared to 8%, p < 0.001) were significantly higher in students claiming to have adequate knowledge. Eleven percent of the students thought about dropping out of dental education because of the COVID-19 pandemic. These students exhibited a markedly increased fear of being at risk for contagion because of the COVID-19 pandemic (80% compared to 64%, p = 0.011). Seventy-six percent of the students were aiming for a dental specialty. Eighteen percent changed their desired specialty, and 25% were in search of a specialty that they believed required fewer close contact procedures. CONCLUSIONS: It is crucial to prepare students for the next possible outbreak using the knowledge gained during this pandemic by modifying the dental curriculum and providing credible information and psychological support to guide dental students in building a healthy career path.

Relationship Between Temporomandibular Ankylosis And Maximum Mouth Opening In Children.

BACKGROUND: Pediatric dentists should have information regarding whether mouth opening is limited. In clinical practice, these professionals should collect and record oral area measurements at the pediatric patient's first medical examination. OBJECTIVES: The study's aim developed the standard mouth opening measurement in children by using ordinary least squares regression to develop a clinical prediction model in children with Temporomandibular Joint Ankylosis before preoperative surgery. METHODS: All participants completed their age, gender, and calculated height, weight, body mass index, and birth weight. Pediatric dentist performed all mouth-opening measurements. The oral-maxillofacial surgeon marked subnasal and pogonion points for the lower facial length of soft tissue. It was measured using the distance between the subnasal and pogonion with a digital vernier caliper. The widths of the three fingers (index, middle, and ring fingers) and four fingers (index, middle, ring, and little fingers) were also measured using a digital vernier caliper. RESULTS: Maximum mouth opening showed that three-finger width (R2 = 0.566, F = 185.479) and four-finger width (R2 = 0.462, F = 122.209) had a significant influence on the Maximum mouth opening (MMO) (p < 0.001). CONCLUSION: Pediatric dentists should collaborate with the treating maxillofacial surgeon to manage long-term treatment needs for individuals with Temporomandibular Joint Ankylosis.

A Comparison of Hard and Soft Occlusal Splints for the Treatment of Nocturnal Bruxism in Children Using the BiteSTRIP®.

OBJECTIVE: Bruxism is defined as a parafunctional activity. It could be in diurnal or nocturnal form, based on the time it occurs. The purpose of the study compares the effectiveness of occlusal splint treatments in children with nocturnal bruxism using the BiteStrip®. STUDY DESIGN: The muscle activity of children was measured using the BiteStrip®. The groups used occlusal splints during nighttime sleep for three months, at the end of which their muscle activity were measured again through the use of the BiteStrip®. RESULTS: Muscle pain in palpation and pain in the dynamic position of TMJ pain was significantly reduced in patients using soft occlusal splint (p=0.01). There was no significant change in the BiteStrip® score in both group I (p=0.11) and group II (p=0.61). CONCLUSION: Soft occlusal splints could reduce pain caused by nocturnal bruxism on muscle and TMJ. The relationship between treatment results and BiteStrip® scores of patients using soft occlusal splint or hard occlusal splint are not significantly.

Consequences of Decompression Treatment With a Special-Made Appliance of Nonsyndromic Odontogenic Cysts in Children.

PURPOSE: Odontogenic cysts can cause changes in bone structure. The purpose of this study is to evaluate the change in bone healing before and after decompression of nonsyndromic odontogenic cysts in children. METHODS: A retrospective cohort study was performed including children diagnosed with nonsyndromic odontogenic cysts between January 2016 and December 2020. Study variables included the measurement times (baseline: T0, 1-month postoperative: T1, and end treatment: T2), measurement regions (middle cyst and control area), maxilla, and mandible. The primary and secondary outcome variables were fractal dimension (FD), treatment time, and cyst volume, respectively. Bone healing was evaluated using the fractal analysis method, the results of which are expressed as the FD. Data were analyzed by Friedman repeated measures analysis of variance by ranks, the Wilcoxon rank, Mann-Whitney U, and Kruskal-Wallis tests, Spearman correlation analysis, and linear regression model. RESULTS: Twenty-three children (9 girls,14 boys) with a mean age of 9.57 ± 2.02 years were included into the study. A comparison of the measurement regions showed that the middle cyst area (1.279 ± 0.090) had significantly lower FD values than control area before decompression (T0; P < .001). Statistically significant differences were observed in FD values at T0, T1, and T2 (1.279 ± 0.090, 1.311 ± 0.090, and 1.384 ± 0.075) in the middle cyst area (P <. 001). After decompression, no significant difference was found in FD values between the middle cyst (1.384 ± 0.075) and the control area (1.401 ± 0.050). CONCLUSIONS: Decompression resulted in successful bone healing in children with odontogenic cysts. Conservative treatment methods should be preferred due to the continuation of growth and development in pediatric patients.

Can zirconia crowns be the first restorative choice after endodontic treatment of primary teeth?

OBJECTIVE: Early loss of primary teeth due to caries can cause temporary or permanent problems, such as occlusion disorders, aesthetic problems, nutritional problems, abnormal habits, and speech disorders. Although the development of restorative materials has led to significant improvements, failures are still frequent. The purpose of this study was to evaluate the success rates of zirconia crowns compared to other crowns for the restoration of endodontically treated teeth with excessive loss of material. METHODS: A total of 45 teeth of patients aged under 10 years, including primary molars and anterior teeth, requiring restoration after root canal treatment, were included in this randomized, non-blinded clinical study. Stainless steel (SSC), zirconia (ZC), and strip (SC) crowns were used and compared clinically and radiographically during a six-month follow-up period. Parents were asked to fill out a questionnaire at one week and six months to evaluate the parent and child satisfaction levels. The patients' pain and discomfort levels were assessed using a visual analogue scale. The Mann-Whitney U, Chi-Squared and Friedman and Cochran Q tests were used for statistical comparisons using IBM SPSS Statistics version 23 (IBM, Armonk, NY, USA). RESULTS: The six-month follow-up evaluations revealed no significant differences in clinical outcomes between the SSC, ZC, and SC groups. There were no significant differences between the groups with respect to parent and child satisfaction. CONCLUSION: The clinical outcomes of ZCs were comparable to those of the other crowns. ZCs could be a choice for aesthetic purposes, with the disadvantage of a higher cost.

The effects of various irrigation protocols on root canal wall adaptation and apical microleakage in primary teeth.

Objective: The objective of this study is to evaluate the wall adaptation and apical microleakage values following the application of various irrigation protocols in primary teeth.Material and methods: For the two parts of the study, extracted upper incisor primary teeth were randomly included to the 1% sodium hypochlorite (NaOCl), 10% ethylenediaminetetraacetic acid (EDTA)+1% NaOCl, 6% citric acid (CA)+1% NaOCl and 0.9% physiological saline (PS) groups. Canal wall adaptation and apical microleakage were assessed by scanning electron microscopy (SEM) and stereomicroscope, respectively.Results: 6% CA + 1% NaOCl group was found to be the most successful irrigation protocol in providing strong canal wall adaptation and less apical microleakage, followed by 10% EDTA +1% NaOCl. 6% CA +1% NaOCl was significantly superior regarding apical microleakage (p < .05).Conclusions: Due to the ability to provide appropriate changes in the root canal walls to make a well-adapted and leak-proof canal filling, 6% CA + 1% NaOCl can be recommended as an irrigation protocol in primary teeth.

The effect of different irrigation protocols on smear layer removal in root canals of primary teeth: a SEM study.

OBJECTIVE: The purpose of this study was to compare the efficacy of different irrigation protocols on smear layer removal in root canals of primary teeth by scanning electron microscopy (SEM). MATERIAL AND METHODS: The study was conducted with 40 extracted maxillary primary incisor teeth divided into four groups (n = 10) as 1% sodium hypochlorite (NaOCl), 10% ethylenediaminetetraacetic acid (EDTA)+1% NaOCl, 6% citric acid (CA)+1% NaOCl, and 0.9% physiological saline (PS). After the irrigation procedures, root canal walls were examined by SEM and the efficacies of irrigation solutions in smear layer removal were scored and compared. Data were analyzed using Kruskal-Wallis, Friedman and Siegel Castellan tests. RESULTS: The smear layer removal was found to be statistically more effective in groups of 10% EDTA + 1% NaOCl and 6% CA + 1% NaOCl when compared with the other groups (p < .05). Smear removal efficacy was statistically significantly higher in coronal and medium thirds when compared with the apical regions in the experimental groups. CONCLUSIONS: It was concluded that 10% EDTA + 1% NaOCl and 6% CA + 1% NaOCl could be alternative irrigation protocols regarding smear layer removal. However, due to the absence of erosive dentinal changes, it might be suggested that using 6% CA + 1% NaOCl can be recommended compared to 10% EDTA + 1% NaOCl in primary root canals.

Eustigmaeus johnstoni Zhang - Gerson (Acari: Stigmaeidae) a Parasitic Mite Species Detected in Phlebotomus papatasi (Diptera: Psychodidae) Specimens Collected from Aydin, Turkey.

OBJECTIVE: We aimed to report the presence of the parasitic mite Eustigmaeus johnstoni Zhang - Gerson (E. johnstoni) on the sand fly species Phlebotomus papatasi (P. papatasi) collected in Aydin province, Turkey. METHODS: Sand flies were collected from nature by CDC light traps in Nazilli town in Aydin province and were separated according to collection localities. Head and genital areas were cut and mounted for species identification, and midgut contents were checked for the possible presence of Leishmania parasites under a light microscope. Mites detected in sand flies were diagnosed on the species level based on the literature. RESULTS: A total of 360 female and 378 male sand flies were caught. During dissection and preparation, two female E. johnstoni parasitic mite specimens belonging to the genus Eustigmaeus were detected on the abdominal pleura of P. papatasi specimens. CONCLUSION: To our knowledge, this is the first study to report the presence E. johnstoni on P. papatasi in Turkey. Previous studies showing the relationship between parasitic mites and sand flies have indicated that this relationship is not accidental. More studies are needed to understand this relationship for obtaining more detailed information.

Prevalence and Density of Demodex folliculorum and Demodex brevis (Acari: Demodicidae) in Erzincan Province.

OBJECTIVE: This study aimed to determine the prevalence and density of Demodex folliculorum and D. brevis in Erzincan Province and the association between Demodex spp. and skin moisture, pH, and temperature. METHODS: The study included total 300 healthy participants without dermatological ailments and residing in Erzincan Province. Moisture, pH, and temperature of the cheek were measured, and the presence of mite was determined in samples from the cheek, nasolabial, and chin region using the standard superficial skin biopsy technique. RESULTS: The prevalence and density of D. folliculorum and D. brevis were found to be 61.3% (mean 14.3/cm2) and 23.3% (mean 3.2/cm2), respectively, in healthy participants. Infestation by Demodex spp. was greater in the cheek (mean 10.4/cm2), followed by the nasolabial region (mean 7.2/cm2) and chin (mean 6.6/cm2), respectively (p<0.001). The prevalence and density of Demodex spp. were greater in those with dry skin (mean 11.6/cm2), pH of 5.5-7.0 (mean 11.2/cm2), and temperature of 20-23°C (mean 13.1/cm2). Males, with aged >60 years, with lower educational status, and who were single were significantly more infested with Demodex spp. CONCLUSION: Demodex mites are very prevalent in healthy individuals with different skin moisture, skin pH, skin temperature, and demographic characteristics. This may be taken into consideration when epidemiological and clinical studies are conducted on patients having different dermatological ailments.

Postoperative Pain After Root Canal Preparation with Hand and Rotary Files in Primary Molar Teeth.

PURPOSE: The purpose of this study was to evaluate the intensity and duration of postoperative pain after root canal preparation of primary maxillary molar teeth using two preparation techniques. METHODS: A total of 110 patients requiring pulpectomy for asymptomatic primary molar teeth with non-vital pulps were included in the study. The patients were randomly assigned to two groups of 55 patients each, according to the canal preparation method used. In Group one, teeth were prepared up to size 35 with hand files. In Group two, teeth were prepared up to size 35 with Revo-S rotary instruments. Following canal preparation, teeth were obturated with zinc-oxide eugenol paste and then permanently restored. The presence of postoperative pain was assessed after six, 12, 24, 48, and 72 hours and after one week, using a four-point pain-intensity scale. RESULTS: Except for those assessed after 72 hours and one week, patients who had their teeth prepared with hand files reported more intense postoperative pain than those who had their teeth prepared with Revo-S rotary files (P<0.05). In both groups, postoperative pain decreased over time. CONCLUSIONS: Hand files caused more postoperative pain after pulpectomy in primary maxillary molar teeth compared to the rotary system.

Sensitivity to House Dust Mites Allergens in Patients with Allergic Asthma in Erzincan Province, Turkey.

OBJECTIVE: To investigate the sensitivity of allergic asthma (AA) patients to house dust mites (HDM) by conducting skin tests, measuring total and specific IgE antibodies to Dermatophagoides pteronyssinus and D. farinae mites, and examining HDM fauna in patients' homes. METHODS: The study included 25 patients with AA and 31 healthy controls, who were challenged with Der p and Der f allergens; serum levels of allergen-specific lgE and total IgE were measured. Dust samples were collected from the homes of all participants, and mite species and the number of mites per gram of dust were investigated. RESULTS: D. pteronyssinus was found in the homes of 94.7% patients with positive Der p reactions in the skin test (p<0.001). D. farinae was found in the homes of 22.2% patients with positive Der f reactions in the skin test (p>0.05). D. pteronyssinus-specific IgE was detected in 75% patients in whose homes D. pteronyssinus was also found, while D. farinae-specific IgE was detected in 16.6% patients in whose homes D. farinae was also found. CONCLUSION: A part of AA patients residing in Erzincan are sensitive to HDM allergens, and high numbers of mites leading to allergic sensitization are found in their homes.

The effect of skin moisture, pH, and temperature on the density of Demodex folliculorum and Demodex brevis (Acari: Demodicidae) in students and staff of the Erzincan University, Turkey.

BACKGROUND: The aim of this study was to determine the prevalence and density of Demodex folliculorum and Demodex brevis in students and staff of the Erzincan University, Turkey, and to define the influence of age, gender, educational level, and hygiene as well as skin moisture, pH, and temperature on the presence of Demodex mites. METHODS: Healthy people without apparent facial dermatoses from nine faculties and five vocational schools of the university were included in the study. The measurements for moisture, pH, and temperature were conducted in the cheek region, while samples for mite presence were taken from the same region using the standard superficial skin biopsy technique. RESULTS: A total of 538 healthy people, 385 students and 153 university staff, were included in the study. Demodex mites were detected in 50.1% of the students (mean 7.1/cm2 ) and in 69.3% of the university staff (mean 13.1/cm2 ). There were statistical differences between the groups of people who were cleaning their face one, two, three, or more times daily and between those who were using and not using personal towels. There was a borderline significant difference between the different age groups and people with different education levels. The density of mites was higher in those with a skin moisture of less than 50%, with a pH of 5-6.5 and temperature of 24-28 °C, however the differences between the groups with different skin moisture, skin pH, and skin temperature were not statistically significant. CONCLUSION: Demodex mites are very prevalent in healthy individuals of both sexes, and this should be taken into consideration when epidemiological and clinical studies are conducted with patients having different dermatological ailments.

Evaluation of root canal morphology of human primary molars by using CBCT and comprehensive review of the literature.

OBJECTIVE: Knowledge of primary tooth morphology is essential for clinical dentistry, especially for root canal treatment and dental traumatology. However, this has not been well documented to date with a large sample. This study was carried out to investigate the variation in number and morphology of the root canals of the primary molars, to study the applicability of cone beam computerized tomography (CBCT) in assessing the same and to provide a comprehensive review of the literature. MATERIALS AND METHODS: A total of 343 primary molars, without any root resorption, were divided into four main groups including the maxillary first molars, maxillary second molars, mandibular first molars and mandibular second molars. All of them were analysed in CBCT images in the axial, sagittal and coronal planes. Various parameters such as the number of roots, number of canals, the root canal type, diameter of root and root canal and root canal curvature were studied. RESULTS: Primary molars in all four groups showed variability in the number of roots and root canals. As far as length of the roots was concerned, the palatal root of the maxillary molar was found to be longest, while the distobuccal root was shortest. In mandibular molars, the mesial root was longer than the distal root. The length of distobuccal root canal of the maxillary molars and the distolingual canal of the mandibular molars was found to be shortest. The number of roots and root canals varied from two to four and three to four, respectively. The maxillary molars exhibited more one-canal than two-canal roots. CONCLUSION: The present study provides comprehensive information to the existing literature concerning the variation in root canal morphology of the maxillary and mandibular primary molar teeth. These data may help clinicians in the root canal treatment of these teeth.

Comparison of Living and Bedrooms in Terms of House Dust Mites in the Province of Erzincan, Turkey.

The most important factors in development of symptoms such as allergic asthma, rhinitis, conjunctivitis, and dermatitis in atopic persons are the allergens of house dust mites. The objective of this study was to compare living rooms and bedrooms, and woolen and spring mattresses in terms of the number and species of mites in houses in the province of Erzincan, Turkey. In total, 74 dust samples were collected from living rooms and bedrooms of 37 randomly selected houses from various districts of the city. All examined houses were positive for house dust mites. In total, 5,210 mites were isolated, 1,058 from the living rooms and 4,152 from the bedrooms, and the differences were statistically significant (P < 0.05). Of 4,152 mites detected in bedrooms, 1,330 (32%) were isolated from 31 spring mattresses and 2,822 (68%) from 6 woolen mattresses (P < 0.001). The study identified 14 families, 17 genera, and 16 species belonging to Astigmata, Prostigmata, and Oribatida. Of these, Dermatophagoides pteronyssinus (Trouessart) was the dominant species: living rooms, 63.3%; bedrooms, 74.4%; woolen mattresses, 84.6%; and spring mattresses, 52.8%. This was followed by Lepidoglyphus destructor (Schrank) (9.8%), Dermatophagoides farinae Hughes (5.1%), Tyrophagus putrescentiae (Schrank) (4.3%), and Acarus siro L. (2.5%) in living rooms; L. destructor (11.2%), Euroglyphus maynei (Cooreman) (4.2%), D. farinae (3.8%), and T. putrescentiae (1.0%) in bedrooms; L. destructor (11.8%), D. farinae (2.1%), E. maynei (0.3%), and T. putrescentiae (0.2%) in woolen mattresses; and E. maynei (12.5%), L. destructor (9.9%), D. farinae (7.5%), and T. putrescentiae (2.7%) in spring mattresses.

House Dust Mites in Erzincan Province.

OBJECTIVE: We aimed to determine the species of the house dust mites seen in Erzincan, the number of mites per gram of dust in the houses, and the relationship between temperature and the number of mite specimens. METHODS: For this purpose, 54 dust samples collected from 18 houses located in different districts of Erzincan province between November 2013 and January 2014. These samples were examined by a lactic acid precipitation method. RESULTS: Of the houses in which the dust samples were collected, 94.44% were found to be positive in terms of mites. A total of 844 mite specimens were isolated from the dust samples, and the mean number of mites per gram of dust was found to be 18.34. The most common species was found to be Acarus siro (55.55%) and was followed by Dermatophagoides pteronyssinus (50.00%), Tyrophagus putrescentiae (22.22%), Histiostoma sp. (22.22%), Lepidoglyphus destructor (16.66%), T. perniciosus(11.11%), Euroglyphus maynei (11.11%), Glycyphagus privatus (11.11%), Cheyletus sp. (11.11%), Tarsonemus sp. (11.11%), and Tetranychus sp. (11.11%). CONCLUSION: Mite-holding rate of the houses in Erzincan province was found to be 94.44%. The mean number of mites per gram of dust was found to be 18.34. The most common mite species was A. siro, which was followed by D. pteronyssinus.

Effects of melatonin on Wi-Fi-induced oxidative stress in lens of rats.

INTRODUCTION: Melatonin has been considered a potent antioxidant that detoxifies a variety of reactive oxygen species in many pathophysiological states of eye. The present study was designed to determine the effects of Wi-Fi exposure on the lens oxidant, antioxidant redox systems, as well as the possible protective effects of melatonin on the lens injury induced by electromagnetic radiation (EMR). MATERIALS AND METHODS: Thirty-two rats were used in the current study and they were randomly divided into four equal groups as follows: First and second groups were cage-control and sham-control rats. Rats in third group were exposed to Wi-Fi (2.45 GHz) for duration of 60 min/day for 30 days. As in the third group, the fourth group was treated with melatonin. The one-hour exposure to irradiation in second, third and fourth took place at noon each day. RESULTS: Lipid peroxidation levels in the lens were slightly higher in third (Wi-Fi) group than in cage and sham control groups although their concentrations were significantly (P < 0.05) decreased by melatonin supplementation. Glutathione peroxidase (GSH-Px) activity was significantly (P < 0.05) lower in Wi-Fi group than in cage and sham control groups although GSH-Px (P < 0.01) and reduced glutathione (P < 0.05) values were significantly higher in Wi-Fi + melatonin group than in Wi-Fi group. CONCLUSIONS: There are poor oxidative toxic effects of one hour of Wi-Fi exposure on the lens in the animals. However, melatonin supplementation in the lens seems to have protective effects on the oxidant system by modulation of GSH-Px activity.

Seasonal changes of house dust mite population in Bitlis and Mus provinces of Turkey.

OBJECTIVE: This study was conducted to determine the dust mite fauna of houses in Bitlis and Mus provinces, the monthly value of mite numbers/g dust, as well as the impact of temperature, humidity and altitude on their numbers. METHODS: Dust samples were collected monthly from May 2010 to April 2011 from six houses belonging to three settlements; two of the houses were located in Bitlis, while another four were in Mus province. RESULTS: All 72 examined dust samples were found to be positive with regard to mites. The number of mites found in 1 g dust varied from 25 to 2,740. Overall, 1,167 house dust mites belonging to the orders Astigmata, Mesostigmata and Prostigmata were isolated. Dermatophagoides pteronyssinus was the predominant mite (83.2%), followed by Lepidoglyphus destructor (6.3%), Acarus siro (2.7%) and Tyrophagus putrescentiae (1.9%). The mite numbers were higher in the warmer months of the year. CONCLUSION: The dominant mite in the Bitlis and Mus provinces is Dermatophagoides pteronyssinus, and the highest mite numbers were found in months in which the outside humidity was low.

2.45-Gz wireless devices induce oxidative stress and proliferation through cytosolic Ca²âº influx in human leukemia cancer cells.

PURPOSE: Electromagnetic radiation from wireless devices may affect biological systems by increasing free radicals. The present study was designed to determine the effects of 2.45 GHz radiation on the antioxidant redox system, calcium ion signaling, cell count and viability in human leukemia 60 cells. MATERIALS AND METHODS: Twelve cell cultures were equally divided into two main groups as controls (n = 6) and irradiated (n = 6) and then subdivided into four different subgroups depending on the duration of exposure, namely 1, 2, 12 and 24 hours. The samples were analyzed immediately after the experimental period. RESULTS: The extent of lipid peroxidation, cytosolic free Ca²âº and cell numbers were higher in 2.45 GHz groups than in the controls. The increase of cytosolic free Ca²âº concentrations was radiation time-dependent and was highest at 24-h exposure. The reduced glutathione, glutathione peroxidase, vitamin C and cell viability values did not show any changes in any of the experimental groups. 2-aminoethyl diphenylborinate inhibits Ca²âº ions influx by blockage of the transient receptor potential melastatin 2. CONCLUSIONS: 2.45 GHz electromagnetic radiation appears to induce proliferative effects through oxidative stress and Ca²âº influx although blocking of transient receptor potential melastatin 2 channels by 2-aminoethyl diphenylborinate seems to counteract the effects on Ca²âº ions influx.

Glutathione modulates Ca(2+) influx and oxidative toxicity through TRPM2 channel in rat dorsal root ganglion neurons.

Glutathione (GSH) is the most abundant thiol antioxidant in mammalian cells and maintains thiol redox in the cells. GSH depletion has been implicated in the neurobiology of sensory neurons. Because the mechanisms that lead to melastatin-like transient receptor potential 2 (TRPM2) channel activation/inhibition in response to glutathione depletion and 2-aminoethyldiphenyl borinate (2-APB) administration are not understood, we tested the effects of 2-APB and GSH on oxidative stress and buthionine sulfoximine (BSO)-induced TRPM2 cation channel currents in dorsal root ganglion (DRG) neurons of rats. DRG neurons were freshly isolated from rats and the neurons were incubated for 24 h with BSO. In whole-cell patch clamp experiments, TRPM2 currents in the rat were consistently induced by H(2)O(2) or BSO. TRPM2 channels current densities and cytosolic free Ca(2+) content of the neurons were higher in BSO and H(2)O(2) groups than in control. However, the current densities and cytosolic Ca(2+) release were also higher in the BSO + H(2)O(2) group than in the H(2)O(2) alone. When intracellular GSH is introduced by pipette TRPM2 channel currents were not activated by BSO, H(2)O(2) or rotenone. BSO and H(2)O(2)-induced Ca(2+) gates were blocked by the 2-APB. Glutathione peroxidase activity, lipid peroxidation and GSH levels in the DRG neurons were also modulated by GSH and 2-APB inhibition. In conclusion, we observed the protective role of 2-APB and GSH on Ca(2+) influx through a TRPM2 channel in intracellular GSH depleted DRG neurons. Since cytosolic glutathione depletion is a common feature of neuropathic pain and diseases of sensory neuron, our findings are relevant to the etiology of neuropathology in DRG neurons.

Effect of tube potential and image receptor on the detection of natural proximal caries in primary teeth.

The aim of this study was to assess the detection of proximal caries in primary teeth at three different tube potentials using Ektaspeed films, storage phosphor plates (SPPs), and a charge-coupled device (CCD). Fifty-three extracted human primary molars with natural proximal caries were radiographed with three different imaging modalities--Digora Optime SPP system, RVGui CCD system, and Ektaspeed films--at 50-, 65-, and 70-kV tube potentials. Three observers scored the resultant images for the presence or absence of caries. The definitive diagnosis was determined by stereomicroscopic assessment. The diagnostic accuracy for each imaging modality was expressed as the area under the receiver operating characteristic curves (A(z)). Differences among the A(z) values were assessed using two-way ANOVA and t tests. Kappa was used to measure inter- and intra-observer agreement. Higher accuracy was found for SPPs compared to film and CCD images at all tube potentials. Accuracy was significantly different only at 50-kV tube setting in favor of SPPs (p < 0.05). Inter- and intra-observer agreement was high for all systems. A SPP system can be recommended for dental peadodontic clinics particularly with 50-kV tube potential for the diagnosis of proximal caries since further advantages include the elimination of chemical processing, image enhancement, and a better low-contrast detectability performance.