Ultrastructure of the Natal and Primary Teeth

Aim: The teeth present in the oral cavity at birth are known as natal teeth and their etiology is still unknown. In this study, we aimed to compare the morphologic structures of natal and primary teeth at the ultra structural level using transmission electron microscope (TEM). Material and Methods: We investigated a natal tooth of a fourteen-day-old newborn baby. It was extracted due to the hypermobility with a risk of aspiration. As a control, a healthy primary incisor tooth was extracted from another child due to the physiologic root resorption. Immediately after extraction, both teeth were fixed in 10% formalin solution and decalcified by immersion in ethylenediaminetetraacetic acid (EDTA) solution. Following routine TEM preparation process, teeth were embedded in Epon 812. Results: Histologically, structures of enamel prism and dentin tubules were different in the natal tooth compared to the primary tooth. Light microscopic (LM) and TEM investigations of the primary tooth showed prominent crystal structures in the enamel prism and regular organization in both enamel and dentin. LM and TEM investigations of the natal tooth revealed an irregular enamel prism in the hypoplastic enamel, vacuolization in the interprismatic enamel and an irregular organization in the dentin tubules. Conclusion: We conclude that the structural differences of the enamel and dentin in the natal tooth might be a result of incomplete maturation

Çalışanların iş tatmin düzeylerinin incelenmesi (Muğla Orman Bölge Müdürlüğü örneği)

Günümüz çalışma hayatında iş tatmininin artan önemi ve ormancılık sektöründeki çalışmaların yetersizliği, bu çalışmanın ortaya çıkışındaki başlıca nedenlerdir. Çalışmanın amacı, yöneticilerin tatmin düzeylerini belirlemek ve böylece gereken tedbirlerin alınabilmesi için öneriler sunmaktır. Çalışmada veri elde etmek için anket yönteminden yararlanılmıştır. Verilerin değerlendirilmesi için bağımsız iki örnek t-testi ve tek yönlü varyans analizi kullanılmıştır. Çalışanların, işin niteliği ve çalışma koşullarına, çalışma arkadaşlarına ve iletişim ve kurum imajına ilişkin tatmin düzeyleri yüksek çıkmıştır. Çalışanların en fazla tatminsizlik duydukları faktörün ücret olduğu ve yaş ilerledikçe ücrete bağlı tatminsizliğin arttığı bulunmuştur. Çalışanların iş tatmin düzeylerini arttırmak için daha iyi ücret politikaları uygulanmalı ve sosyal imkânlar iyileştirilmelidir. Anahtar Kelimeler: İş tatmini, Varyans analizi, Orman Bölge Müdürlüğü, Muğl

Prevalence of Black Stain and Dental Caries in Children Attending a University Pediatric Dentistry Clinic in Istanbul

Objective: The purpose of the present study is to investigate the prevalence of black stain and dental caries in Istanbul schoolchildren attending a university pediatric dentistry clinic and compare it with the literature findings from other countries. Methods: Presence of black stain and WHO df-t/DMF-T scores were recorded from randomly selected 325 (boys: 167, girls: 158) schoolchildren between 5 to 13 years of age who reside in Istanbul and attend Marmara University Pediatric Dentistry Clinic. Results: Black stain was observed in 60 children (27 boys, 33 girls). The overall percentage of children affected by black stain was 18.5%. The mean df-t, DMF-T scores for children with black stain (3.67 +/- 3.25; 1.39 +/- 1.68) did not differ from children without black stain (4.29 +/- 3.48; 1.79 +/- 2) (p>0.05). Number of children with and without black stain did not differ according to DMF-T and df-t scores, gender, parental education levels and toothbrushing frequency (p>0.05). Conclusions: The mean df-t and DMF-T scores were not statistically different between the groups with stain and without stain. Black staining and df-t, DMF-T scores were not associated with each other. The prevalence of staining in our sample was found higher than the prevalence reported from Brazil, Italy, Germany, Spain, Poland, Philippines, India, Greece, and China but lower than those reported from Switzerland and United Kingdom

Two-colour chewing gum mixing ability test for evaluating masticatory performance in children with mixed dentition: validity and reliability study

The unappealing taste of the chewing material and the time-consuming repetitive task in masticatory performance tests using artificial foodstuff may discourage children from performing natural chewing movements. Therefore, the aim was to determine the validity and reliability of a two-colour chewing gum mixing ability test for masticatory performance (MP) assessment in mixed dentition children. Masticatory performance was tested in two groups: systemically healthy fully dentate young adults and children in mixed dentition. Median particle size was assessed using a comminution test, and a two-colour chewing gum mixing ability test was applied for MP analysis. Validity was tested with Pearson correlation, and reliability was tested with intra-class correlation coefficient, Pearson correlation and Bland-Altman plots. Both comminution and two-colour chewing gum mixing ability tests revealed statistically significant MP differences between children (n = 25) and adults (n = 27, both P < 0.01). Pearson correlation between comminution and two-colour chewing gum mixing ability tests was positive and significant (r = 0.418, P = 0.002). Correlations for interobserver reliability and test-retest values were significant (r = 0.990, P = 0.0001 and r = 0.995, P = 0.0001). Although both methods could discriminate MP differences, the comminution test detected these differences generally in a wider range compared to two-colour chewing gum mixing ability test. However, considering the high reliability of the results, the two-colour chewing gum mixing ability test can be used to assess masticatory performance in children, especially at non-clinical settings

Isolation and in vitro characterisation of dental pulp stem cells from natal teeth

Dental pulp stem cells were primarily derived from the pulp tissues of exfoliated deciduous teeth, primary incisors and permanent third molar teeth. The aim of this study was to isolate and extensively characterise SCs derived from human natal dental pulp (hNDP). For characterisation, proliferation capacity, phenotypic properties, ultrastructural and differentiation characteristics and gene expression profiles were utilised. A comparison was done between the properties of NDP-SCs and the properties of mesenchymal stem cells (MSCs) from bone marrow (BM) of the human. Stem cells isolated from hNDP and hBM were analysed by flow cytometry, reverse transcriptase-PCR, Real Time-PCR, and immunocytochemistry. Both cell lines were directionally differentiated towards adipogenic, osteogenic chondrogenic, myogenic and neurogenic lineages. hNDP-SCs and hBM-MSCs expressed CD13, CD44, CD90, CD146 and CD166, but not CD3, CD8, CD11b, CD14, CD15, CD19, CD33, CD34, CD45, CD117, and HLA-DR. Ultrastructural characteristics of hNDP-SCs showed more developed and metabolically active cells. hNDP-SCs and hBM-MSCs expressed some adipogenic (leptin, adipophilin and PPAR gamma), myogenic (desmin, myogenin, myosinIIa, and alpha-SMA), neurogenic (gamma-enolase, MAP2a,b, c-fos, nestin, NF-H, NF-L, GFAP and betaIII tubulin), osteogenic (osteonectin, osteocalcin, osteopontin, Runx-2, and type I collagen) and chondrogenic (type II collagen, SOX9) markers without any stimulation towards differentiation under basal conditions. Embryonic stem cell markers Oct4, Rex-1, FoxD-3, Sox2, and Nanog were also identified. The differentiation potential of hNDP-SCs and hBM-MSCs to adipogenic, osteogenic, chondrogenic, myogenic and neurogenic was shown. This report described the first successful isolation and characterisation of hNDP-SCs

Mycological and cytological examination of oral candidal carriage in diabetic patients and non-diabetic control subjects: thorough analysis of local aetiologic and systemic factors

In this study, 55 diabetic patients and 45 non-diabetic control subjects were examined to determine oral candidal carriage state. The influence of some local aetiologic and systemic factors such as: salivary flow rate and pH, heredity, alcohol drinking, smoking habits, antimicrobial therapy, wearing of denture, burning sensation, dry mouth, taste alteration and tooth brushing habit on candidal carriage rate were investigated. Imprint culture, cytological smears and biochemical tests were used. Oral carrier rate and density of Candida species were non-significantly higher in the diabetic patients than in the non-diabetic control subjects. This increase was confirmed cytologically too. In both groups, Candida albicans was found to be a predominant species on tongue dorsum. Cigarette and alcohol habits of men were higher while tooth brushing habit was less than in women in diabetic and control groups. Salivary flow rate and pH values of diabetic patients were significantly lower while serum glucose values were significantly higher than of non-diabetic controls. The rate of diabetic patients suffering from dry mouth and having diabetic heredity in the family were significantly higher than control subjects. The candidal colonization was higher and keratinization was lower while diabetic treatment tended from diet and oral antidiabetic towards insulin. The decrease in salivary pH, the increase in serum glucose and wearing denture were correlated with the increased rate and density of C. albicans in both groups. Keratinization was also accompanied with the increase in leucocytes. In diabetic group, positive correlations were found between antimicrobial therapy and C. glabrata carriage; the increase in leucocytes and C. albicans carriage; the increase in keratinization and alcohol habit; serum glucose and smoking habit; dry mouth complaint and antimicrobial therapy. There was a negative correlation between salivary flow rate and C. albicans carriage. In control group a positive correlation was found between antimicrobial therapy and keratinization