The effect of dentin desensitizers and Nd:YAG laser pre-treatment on microtensile bond strength of self-adhesive resin cement to dentin

Acar, Ozlem,Tuncer, Duygu,Yuzugullu, Bulem,Celik, Cigdem The Korean Academy of Prosthodonitics 2014 The Journal of Advanced Prosthodontics Vol.6 No.2

PURPOSE. The purpose of this study is to evaluate if pre-treatment with desensitizers have a negative effect on microtensile bond strength before cementing a restoration using recently introduced self-adhesive resin cement to dentin. MATERIALS AND METHODS. Thirty-five human molars' occlusal surfaces were ground to expose dentin; and were randomly grouped as (n=5); 1) Gluma-(Glutaraldehyde/HEMA) 2) Aqua-Prep F-(Fluoride), 3) Bisblock-(Oxalate), 4) Cervitec Plus-(Clorhexidine), 5) Smart protect-(Triclosan), 6) Nd:YAG laser, 7) No treatment (control). After applying the selected agent, RelyX U200 self-adhesive resin cement was used to bond composite resin blocks to dentin. All groups were subjected to thermocycling for 1000 cycles between $5-55^{\circ}C$. Each bonded specimen was sectioned to microbars ($6mm{\times}1mm{\times}1mm$) (n=20). Specimens were submitted to microtensile bond strength test at a crosshead speed of 0.5 mm/min. Kolmogorov-Smirnov, Levene's test, Kruskal-Wallis One-way Analysis of Variance, and Conover's nonparametric statistical analysis were used (P<.05). RESULTS. Gluma, Smart Protect and Nd:YAG laser treatments showed comparable microtensile bond strengths compared with the control group (P>.05). The microtensile bond strengths of Aqua-Prep F, and Cervitec Plus were similar to each other but significantly lower than the control group (P<.05). Bisblock showed the lowest microtensile bond strength among all groups (P<.001). Most groups showed adhesive failure. CONCLUSION. Within the limitation of this study, it is not recommended to use Aqua-prep F, Cervitec Plus and Bisblock on dentin when used with a self-adhesive resin cement due to the decrease they cause in bond strength. Beside, pre-treatment of dentin with Gluma, Smart protect, and Nd:YAG laser do not have a negative effect.

Comparison of micro-computerized tomography and cone-beam computerized tomography in the detection of accessory canals in primary molars

Acar, Buket,Kamburoglu, Kivanc,Tatar, Ilkan,Arikan, Volkan,Celik, Hakan Hamdi,Yuksel, Selcen,Ozen, Tuncer Korean Academy of Oral and Maxillofacial Radiology 2015 Imaging Science in Dentistry Vol.45 No.4

Purpose: This study was performed to compare the accuracy of micro-computed tomography (CT) and cone-beam computed tomography (CBCT) in detecting accessory canals in primary molars. Materials and Methods: Forty-one extracted human primary first and second molars were embedded in wax blocks and scanned using micro-CT and CBCT. After the images were taken, the samples were processed using a clearing technique and examined under a stereomicroscope in order to establish the gold standard for this study. The specimens were classified into three groups: maxillary molars, mandibular molars with three canals, and mandibular molars with four canals. Differences between the gold standard and the observations made using the imaging methods were calculated using Spearman's rho correlation coefficient test. Results: The presence of accessory canals in micro-CT images of maxillary and mandibular root canals showed a statistically significant correlation with the stereomicroscopic images used as a gold standard. No statistically significant correlation was found between the CBCT findings and the stereomicroscopic images. Conclusion: Although micro-CT is not suitable for clinical use, it provides more detailed information about minor anatomical structures. However, CBCT is convenient for clinical use but may not be capable of adequately analyzing the internal anatomy of primary teeth.

Agricultural Unskilled Labor Mobility : Does It Matter?

ACAR, Mustafa 세종대학교 국제경제연구소 2003 Journal of Economic Integration Vol.18 No.1

Labor mobility is on important issue in quantiative economic analyses due to its possible implications for the sectoral reallocation of factors of production, output response, prices, and wages. This paper investigates the issue of agricultural unskilled labor mobility from both modeling and empirical perspectives. After discussing the issue from a theoretical perspective, I look into the empirical implications fo treating agricultural unskilled labor less than mobile in the context of Turkey-EU agricaultural integration. The results indicate that degree of mobility of the agricultural unskilled labor moatters. It has certaqtin implications on sectoral labor mobility between farm and non-farm sectors, the higher the output response, and the lower the real earnings of unskilled labor in agriculture.

A Comparison of Models for Predicting Discretionary Accruals: A Cross-Country Analysis

ACAR, Goksel,COSKUN, Ali Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.9

In this study, we examined various aspects of discretionary accruals. We compared the power of Jones Model (JM), Modified Jones Model (MJM) and Performance Matched Model (PMM). Furthermore, we tested whether accruals derived from cash flow approach or balance sheet approach provide better results and we investigated the significance of country and industry control variables in models. In order to perform these tests, we constructed thirty equations. The data consists of 319 non-financial companies over five years in the GCC region. We used panel data regression models, and testing suggests us to use random effect model as the most suitable one. The results show that PMM has the highest explanatory power among models and it is followed by JM and MJM, consecutively. Secondly, results reveal that accruals derived from cash flow approach provide more accurate results. Moreover, country dummies are significant in models with cash flow approach and they lose significance in balance sheet approach. We differentiated industries due to two different classifications: the first group with higher number of industries is more precise compared to the second group with a narrower scope and lower number of industries. The model including both industrial and country-wise dummies scores highest in significance.

The Mechanical Effect of Rod Contouring on Rod-Screw System Strength in Spine Fixation

Acar, Nihat,Karakasli, Ahmet,Karaarslan, Ahmet A.,Ozcanhan, Mehmet Hilal,Ertem, Fatih,Erduran, Mehmet The Korean Neurosurgical Society 2016 Journal of Korean neurosurgical society Vol.59 No.5

Objective : Rod-screw fixation systems are widely used for spinal instrumentation. Although many biomechanical studies on rod-screw systems have been carried out, but the effects of rod contouring on the construct strength is still not very well defined in the literature. This work examines the mechanical impact of straight, $20^{\circ}$ kyphotic, and $20^{\circ}$ lordotic rod contouring on rod-screw fixation systems, by forming a corpectomy model. Methods : The corpectomy groups were prepared using ultra-high molecular weight polyethylene samples. Non-destructive loads were applied during flexion/extension and torsion testing. Spine-loading conditions were simulated by load subjections of 100 N with a velocity of $5mm\;min^{-1}$, to ensure 8.4-Nm moment. For torsional loading, the corpectomy models were subjected to rotational displacement of $0.5^{\circ}\;s^{-1}$ to an end point of $5.0^{\circ}$, in a torsion testing machine. Results : Under both flexion and extension loading conditions the stiffness values for the lordotic rod-screw system were the highest. Under torsional loading conditions, the lordotic rod-screw system exhibited the highest torsional rigidity. Conclusion : We concluded that the lordotic rod-screw system was the most rigid among the systems tested and the risk of rod and screw failure is much higher in the kyphotic rod-screw systems. Further biomechanical studies should be attempted to compare between different rod kyphotic angles to minimize the kyphotic rod failure rate and to offer a more stable and rigid rod-screw construct models for surgical application in the kyphotic vertebrae.

Perspectives of Women during Reproductive Years for Cervical Cancer Scans and Influencing Factors

Acar, Gokce Banu,Pinar, Gul Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.16

Background: This descriptive study was performed in order to assess health perspectives of women, who applied to Yildirim Beyazit University Ataturk Education and Research Hospital, Outpatient Clinic of Obstetrics and Gynecology for cervical cancer scans and were in the reproductive years. Factors influencing their perspectives were also assessed. Materials and Methods: In this study, a simple random sampling formula was adopted to calculate the volume (300) of the targeted sample. Results of the research were obtained through individual diagnosis form and cervical cancer and the Pap smear test health belief model scale (HBMS). Results: It was found that 75.0% of the women heard of the Pap smear test before, and 48.7% had undertaken one. Some 51.4% of the women who had Pap smear test expressed that they had the test at irregular periods. Most of the women stated that they heard about the smear test from the health staff (51.7%). Lack of any health complaints (28.3%) and not having adequate information about the test (21.0%) were among the reasons for not undergoing a Pap smear test. It was found that lower dimension average scores of the women obtained from the cervical cancer and Pap smear test HBMS varied from $7.7{\pm}2.3$ to $33.5{\pm}9.3$. When the lower dimension average scores of women from the HBMS were examined, the perception of usefulness was high but the susceptibility and health motivations were low. Conclusions: In this study, it was determined that the awareness of women about cervical cancer and the Pap smear test was insufficient, and susceptibility and motivation perception towards having a Pap smear test were low.

South-East Asian Integration in the Context of OIC: Implications of Free Trade among Malaysia, Indonesia and Bangladesh

( Mustafa Acar ),( Savas Alpay ),( Esat Bakimli ),( Zehra Zumrut Koc ) 세종대학교 경제통합연구소 2009 Journal of Economic Integration Vol.24 No.1

Organization of the Islamic Conference (OIC) is the second largest intergovernmental organization after UN with its 57 members. OIC accounts for 22.48 percent of world population, 6.64 percent of world GDP, and 9.1 percent of world trade as of 2007. When it comes to having world valuable resources, OIC`s potential is even more striking with more than 70% of oil and nearly 50% of natural gas reserves of the world. However, the level of economic integration and volume of trade among OIC members over the last 4 decades has been less than satisfactory. But recently there have been some efforts towards increased economic cooperation among the member countries as a key strategy for higher economic growth and welfare. Protocol on Preferential Tariff Scheme (PRETAS) signed by nearly a dozen countries proposes a preferential trade regime among the member states. Further steps in the coming years, including possible free trade areas and customs union are also on the agenda. In this context, this paper looks into the likely consequences of an economic integration among three OIC member countries: Malaysia, Indonesia, and Bangladesh. This could be seen as a first step to investigate the possible gains from more comprehensive economic integration initiative including all members of the OIC. Using a multi-sector, multi-country computable general equilibrium framework, we investigate the impact of full trade liberalization among Malaysia, Indonesia and Bangladesh. One should stress that there is not a simple and clear-cut conclusion one can derive: depending on the nature and the degree of integration, the results vary. The simulation results indicate that free trade among these three countries will likely benefit Indonesia and Malaysia while leading to some welfare loss for Bangladesh. Based on the results, it can be suggested that mechanisms be developed in order to strengthen the adjustment capacity of the less developed trade partners. Correspondingly, instead of FTAs, preferential trade arrangements can be considered in the beginning in accordance with the priorities of countries focusing on certain sectors in which they have comparative advantage. Larger integrations may be achieved in the long term gradually through such small-scale integrations.

Rate of convergence for generalized Szasz operators with derivatives of bounded variation

TUNCER ACAR 장전수학회 2013 Proceedings of the Jangjeon mathematical society Vol.16 No.1

The present paper deals with the general integral modi…-cation of the Szasz-Mirakyan operators having the weight functions ofgeneral Baskakov basis functions.We estimate the rate of convergencefor functions having derivatives of bounded variation.

LEVERAGING BIG DATA AND ARTIFICIAL INTELLIGENCE FOR SERVICE INNOVATION IN MARKETING

Murat Acar,Aysegul Toker 글로벌지식마케팅경영학회 2020 Global Marketing Conference Vol.2020 No.11

The effect of dentin desensitizers and Nd:YAG laser pre-treatment on microtensile bond strength of selfadhesive resin cement to dentin

Ozlem Acar,Duygu Tuncer,Bulem Yuzugullu,Cigdem Celik 대한치과보철학회 2014 The Journal of Advanced Prosthodontics Vol.6 No.2

PURPOSE. The purpose of this study is to evaluate if pre-treatment with desensitizers have a negative effect on microtensile bond strength before cementing a restoration using recently introduced self-adhesive resin cement to dentin. MATERIALS AND METHODS. Thirty-five human molars’occlusal surfaces were ground to expose dentin; and were randomly grouped as (n=5); 1) Gluma-(Glutaraldehyde/HEMA) 2) Aqua-Prep F-(Fluoride), 3) Bisblock-(Oxalate), 4) Cervitec Plus-(Clorhexidine), 5) Smart protect-(Triclosan), 6) Nd:YAG laser, 7) No treatment(control). After applying the selected agent, RelyX U200 self-adhesive resin cement was used to bond composite resin blocks to dentin. All groups were subjected to thermocycling for 1000 cycles between 5-55°C. Each bonded specimen was sectioned to microbars (6 mm × 1 mm × 1 mm) (n=20). Specimens were submitted to microtensile bond strength test at a crosshead speed of 0.5 mm/min. Kolmogorov-Smirnov, Levene’ test, Kruskal–allis One-way Analysis of Variance, and Conover’ nonparametric statistical analysis were used(P<.05). RESULTS. Gluma, Smart Protect and Nd:YAG laser treatments showed comparable microtensile bond strengths compared with the control group (P>.05). The microtensile bond strengths of Aqua-Prep F, and Cervitec Plus were similar to each other but significantly lower than the control group (P<.05). Bisblock showed the lowest microtensile bond strength among all groups (P<.001). Most groups showed adhesive failure. CONCLUSION. Within the limitation of this study, it is not recommended to use Aqua-prep F, Cervitec Plus and Bisblock on dentin when used with a self-adhesive resin cement due to the decrease they cause in bond strength. Beside, pre-treatment of dentin with Gluma, Smart protect, and Nd:YAG laser do not have a negative effect.