Effects of demineralizaton-inhibition procedures on the bond strength of brackets bonded to demineralized enamel surface

Ekizer, Abdullah,Zorba, Yahya Orcun,Uysal, Tancan,Ayrikcil, Servet The Korean Association Of Orthodontists 2012 대한치과교정학회지 Vol.42 No.1

Objective: To study and compare the effects of different demineralization-inhibition methods on the shear bond strength (SBS) and fracture mode of an adhesive used to bond orthodontic brackets to demineralized enamel surfaces. Methods: Eighty freshly extracted, human maxillary premolars were divided into 4 equal groups and demineralized over the course of 21 days. Brackets were bonded to the demineralized enamel of teeth in Group 1. In Group 2, bonding was performed following resin infiltration ($ICON^{(R)}$, DMG, Hamburg, Germany). Before bonding, pre-treatment with acidulated phosphate fluoride (APF) or solutions containing casein phosphopeptide-amorphous calcium phosphate with 2% neutral sodium fluoride (CPP-ACP/wF) was performed in Groups 3 and 4, respectively. The SBS values of the brackets were measured and recorded following mechanical shearing of the bracket from the tooth surface. The adhesive remnant index (ARI) scores were determined aft er the brackets failed. Statistical comparisons were performed using one-way ANOVA, Tukey's post-tests, and G-tests. Results: Significant differences were found in some of the intergroup comparisons of the SBS values (F = 39.287, p < 0.001). No significant differences were found between the values for the APF-gel and control groups, whereas significantly higher SBS values were recorded for the resin-infiltrated and CPP-ACP/wF-treated groups. The ARI scores were also significantly different among the 4 groups (p < 0.001). Conclusions: Tooth surfaces exposed to resin infiltration and CPP-ACP/wF application showed higher debonding forces than the untreated, demineralized surfaces.

Skin Findings in Newborns and Their Relationship with Maternal Factors: Observational Research

( Ozlem Ekiz ),( Ulker Gul ),( Leyla Mollamahmutoglu ),( Muzeyyen Gonul ) 대한피부과학회 2013 Annals of Dermatology Vol.25 No.1

Background: Cutaneous lesions are commonly seen in the newborn period and exhibit inconsistency from the skin lesions of an adult. Objective: The present study was carried out with an aim to determine the frequency of physiologic and pathologic cutaneous findings in newborns. Methods: Typically, 1234 newborns were included in this study. A questionnaire about maternal gestational history, maternal and family history was issued to the parents of each newborn. The presence of cutaneous lesions was recorded. Results: Overall, 642 (52%) of the newborns were male and 592 (48%) were female. Typically, 831 newborns (67.3%) had at least one cutaneous lesion. The prevalence of genital hyperpigmentation and milia was significantly higher in males. In premature newborns, the pervasiveness of cutis marmorata and genital hyperpigmentation was found to be significantly higher. Caput succedaneum, transient neonatal pustular melanosis and cyanosis appeared predominantly in vaginally born infants. Erythema toxicum neonatorum was seen in infants, who were born by cesarean section. The predominance of Mongolian spots and erythema toxicum neonatorum were significantly higher in the newborns of the multiparous mothers; however, caput succedaneum was significantly higher in newborns of the primiparous mothers. Conclusion: A number of studies about neonatal dermatoses have been carried out involving different methods in various countries. We consider that our study may be useful in literature, as it has been carried out involving large number of maternal parameters. (Ann Dermatol 25(1) 1∼4, 2013)

Effects of demineralizaton-inhibition procedures on the bond strength of brackets bonded to demineralized enamel surface

Abdullah Ekizer,Yahya Orcun Zorba,Tancan Uysal,Servet Ayrikcil 대한치과교정학회 2012 대한치과교정학회지 Vol.42 No.1

Objective: To study and compare the effects of different demineralizationinhibition methods on the shear bond strength (SBS) and fracture mode of an adhesive used to bond orthodontic brackets to demineralized enamel surfaces. Methods: Eighty freshly extracted, human maxillary premolars were divided into 4 equal groups and demineralized over the course of 21 days. Brackets were bonded to the demineralized enamel of teeth in Group 1. In Group 2, bonding was performed following resin infiltration (ICON®, DMG, Hamburg, Germany). Before bonding, pre-treatment with acidulated phosphate fluoride (APF) or solutions containing casein phosphopeptide-amorphous calcium phosphate with 2% neutral sodium fluoride (CPP-ACP/wF) was performed in Groups 3 and 4, respectively. The SBS values of the brackets were measured and recorded following mechanical shearing of the bracket from the tooth surface. The adhesive remnant index (ARI) scores were determined after the brackets failed. Statistical comparisons were performed using one-way ANOVA, Tukey’s post-tests, and G-tests. Results: Significant differences were found in some of the intergroup comparisons of the SBS values (F = 39.287, p < 0.001). No significant differences were found between the values for the APF-gel and control groups, whereas significantly higher SBS values were recorded for the resin-infiltrated and CPPACP/wF-treated groups. The ARI scores were also significantly different among the 4 groups (p < 0.001). Conclusions: Tooth surfaces exposed to resin infiltration and CPP-ACP/wF application showed higher debonding forces than the untreated, demineralized surfaces.

Elevated Serum Neutrophil to Lymphocyte and Platelet to Lymphocyte Ratios Could be Useful in Lung Cancer Diagnosis

Kemal, Yasemin,Yucel, Idris,Ekiz, Kubilay,Demirag, Guzin,Yilmaz, Bahiddin,Teker, Fatih,Ozdemir, Meltem Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Background: Lung cancer (LC) is still the primary cause of cancer deaths worldwide, and late diagnosis is a major obstacle to improving lung cancer outcomes. Recently, elevated preoperative or pretreatment neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR) and mean platelet volume (MPV) detected in peripheral blood were identified as independent prognostic factors associated with poor survival with various cancers, including colon cancer, esophageal cancer, gastric cancer and breast cancer. Objective: The aim of this study was to examine whether MPV, NLR and PLR could be useful inflammatory markers to differentiate lung cancer patients from healthy controls. An investigation was also made of the relationship between these markers and other prognostic factors and histopathological subgroups. Materials and Methods: Retrospectively eighty-one lung cancer patients and 81 age-sexes matched healthy subjects included into the study. Patients with hypertension, hematological and renal disease, heart failure, chronic infection, hepatic disorder and other cancer were excluded from the study. The preoperative or pretreatment blood count data was obtained from the recorded computerized database. Results: NLR and PLR values were significantly higher in the LC patients compared to the healthy subjects.( NLR: 4.42 vs 2.45 p=0.001, PLR: 245.1 vs 148.2 p=0.002) MPV values were similar in both groups (7.7 vs 7.8). No statistically significant relationship was determined between these markers (MPV, NLR and PLR) and histopathological subgroups and TNM stages. Conclusions: NLR and PLR can be useful biomarkers in LC patients before treatment. Larger prospective studies are required to confirm these findings.

Soil structure interaction effects on strength reduction factors

Eser, Muberra,Aydemir, Cem,Ekiz, Lbrahim Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.41 No.3

In this study, strength reduction factors are investigated for SDOF systems with period range of 0.1-3.0 s with elastoplastic behavior considering soil structure interaction for 64 different earthquake motions recorded on different site conditions such as rock, stiff soil, soft soil and very soft soil. Soil structure interacting systems are modeled and analyzed with effective period, effective damping and effective ductility values differing from fixed-base case. For inelastic time history analyses, Newmark method for step by step time integration was adapted in an in-house computer program. Results are compared with those calculated for fixed-base case. A new equation is proposed for strength reduction factor of interacting system as a function of structural period of system (T), ductility ratio (${\mu}$) and period lengthening ratio (T/T). It is concluded that soil structure interaction reduces the strength reduction factors for soft soils, therefore, using the fixed-base strength reduction factors for interacting systems lead to non-conservative design forces.

Soil structure interaction effects on strength reduction factors

Muberra Eser,Cem Aydemir,Ibrahim Ekiz 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.41 No.3

In this study, strength reduction factors are investigated for SDOF systems with period range of 0.1-3.0 s with elastoplastic behavior considering soil structure interaction for 64 different earthquake motions recorded on different site conditions such as rock, stiff soil, soft soil and very soft soil. Soil structure interacting systems are modeled and analyzed with effective period, effective damping and effective ductility values differing from fixed-base case. For inelastic time history analyses, Newmark method for step by step time integration was adapted in an in-house computer program. Results are compared with those calculated for fixed-base case. A new equation is proposed for strength reduction factor of interacting system as a function of structural period of system (T), ductility ratio (μ) and period lengthening ratio (T/T). It is concluded that soil structure interaction reduces the strength reduction factors for soft soils, therefore, using the fixed-base strength reduction factors for interacting systems lead to nonconservative design forces.

Inelastic Displacement Ratios for Structures with Foundation Flexibility

Müberra Eser,Cem Aydemir,Ibrahim Ekiz 대한토목학회 2012 KSCE JOURNAL OF CIVIL ENGINEERING Vol.16 No.1

Inelastic displacement ratios have been generally investigated for fixed-base systems without taking into consideration soil structure interaction. In this study, inelastic displacement ratios are investigated for SDOF systems with period range of 0.1-3.0 s with elastoplastic behavior considering soil structure interaction for 64 different earthquake motions recorded on different site conditions such as rock, stiff soil, soft soil and very soft soil. Soil structure interacting systems are modeled with effective period, effective damping and effective ductility values differing from fixed-base case. For inelastic time history analyses, Newmark method for step by step time integration was adapted in an in-house computer program. Results are compared with those calculated for fixed-base case. A new equation is proposed for inelastic displacement ratio of interacting system as a function of structural period of interacting system ( ), ductility ratio (μ) and period lengthening ratio ( /T). The fitness of the regressed function of the inelastic displacement factor is shown in figures. The regressed equation for μ should be useful in estimating the inelastic deformation of structure where the global ductility capacity can be estimated.