Effects of pain catastrophizing and anxiety on analgesic use after surgical removal of impacted mandibular third molars

Altan, Ahmet,Akkoc, Sumeyra,Erdil, Aras,Colak, Sefa,Demir, Osman,Altan, Halenur The Korean Dental Society of Anesthsiology 2019 Journal of Dental Anesthesia and Pain Medicine Vol.19 No.6

Background: In dentistry, pain is a factor that negatively affects treatments and drug use. The aim of this study was to evaluate the correlations of the postoperative analgesic use with pain catastrophizing and anxiety in patients who underwent removal of an impacted mandibular third molar. Methods: We recruited 92 patients who underwent the extraction of impacted mandibular third molar. In this study, the Pederson index was used to preoperatively determine the difficulty of surgical extraction. Patients were asked to note the number of analgesics used for 7 postoperative days. Patients were divided into two groups based on the Pain Catastrophizing Scale: low and high score groups. State-Trait Anxiety Inventory-trait and State-Trait Anxiety Inventory-state questionnaires were used to determine the anxiety levels of the patients. The obtained data were examined to evaluate the correlations of pain catastrophizing and anxiety with the postoperative analgesic use. Results: In this study, 92 patients, including 60 women and 32 men, were recruited. The analgesic use was higher in women than in men but with no significant difference (P > 0.05). Pain Catastrophizing Scale scores were higher in women than in men but with no significant difference (P > 0.05). The analgesic use was higher in patients with high pain catastrophizing than in those with low pain catastrophizing but with no significant difference (P > 0.05). State-Trait Anxiety Inventory-trait scores were higher in women than in men but with no significant difference. However, state-Trait Anxiety Inventory-state scores were significantly higher in women than in men (P < 0.05). Conclusion: The postoperative analgesic use may be higher in patients who catastrophize pain than in others. Knowing the patient's catastrophic characteristics preoperatively would contribute to successful pain management and appropriate drug selection.

Numerical and experimental analysis of a 3D printed Savonius rotor with built-in extension plate

Altan, Burcin Deda,Kovan, Volkan,Altan, Gurkan Techno-Press 2018 Wind and Structures, An International Journal (WAS Vol.27 No.1

In this study, the enhancement of the conventional Savonius wind rotor performance with extension plate has been investigated experimentally and numerically. Experimental models used in the study have been produced with 3D (three dimensional) printing, which is one of the rapid prototyping techniques. Experiments of produced Savonius wind rotor models have been carried out in a wind tunnel. CFD (Computational Fluid Dynamics) analyses have been performed under the same experimental conditions to ensure that experiments and numerical analyses are supported to each other. An additional extension plate has been used in order to enhance the performance of the conventional Savonius wind rotor with a gap distance between blades. It can be called modified Savonius rotor or Savonius rotor with built-in extension plate. Thus, the performance of the rotor has been enhanced without using additional equipment other than the rotor itself. Numerical and experimental analyses of Savonius wind rotor models with extension plate have been carried out under predetermined boundary conditions. It has been found that the power coefficient of the modified Savonius rotor is increased about 15% according to the conventional Savonius rotor.

Elastic-plastic thermal stress analysis of an aluminum composite disc under parabolic thermal load distribution

Gürkan Altan,Muzaffer Topçu,Numan Behlül Bektaş,Burçin Deda Altan 대한기계학회 2008 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.22 No.12

An elastic-plastic thermal stress analysis was carried out on an orthotropic aluminum metal matrix composite disc with a hole by using an analytical solution. The thermal load distribution was chosen to vary parabolically from inner surface to outer surface. An aluminum composite disc reinforced curvilinearly by steel fibers was produced under hydraulic press. The mechanical properties of the composite disc were obtained from experiments by using strain gauges. A computer program was developed to calculate the thermal stresses under a parabolic temperature from inner surface to outer surface. The material was assumed to be non-linear hardening. The elastic-plastic solution was performed for the plastic region expanded around the inner surface by an analytical method. The magnitude of the tangential stress component for elastic and elastic-plastic was higher than the magnitude of the radial stress component. Besides, the tangential stress component was compressive on the inner surface and tensile on the outer surface. The magnitude of the tangential residual stress component was the highest on the inner surface of the composite disc. The plastic region began at the inner surface of disc.

Numerical and experimental analysis of a 3D printed Savonius rotor with built-in extension plate

Burcin Deda Altan,Volkan Kovan,Gurkan Altan 한국풍공학회 2018 Wind and Structures, An International Journal (WAS Vol.27 No.1

In this study, the enhancement of the conventional Savonius wind rotor performance with extension plate has been investigated experimentally and numerically. Experimental models used in the study have been produced with 3D (three dimensional) printing, which is one of the rapid prototyping techniques. Experiments of produced Savonius wind rotor models have been carried out in a wind tunnel. CFD (Computational Fluid Dynamics) analyses have been performed under the same experimental conditions to ensure that experiments and numerical analyses are supported to each other. An additional extension plate has been used in order to enhance the performance of the conventional Savonius wind rotor with a gap distance between blades. It can be called modified Savonius rotor or Savonius rotor with built-in extension plate. Thus, the performance of the rotor has been enhanced without using additional equipment other than the rotor itself. Numerical and experimental analyses of Savonius wind rotor models with extension plate have been carried out under predetermined boundary conditions. It has been found that the power coefficient of the modified Savonius rotor is increased about 15% according to the conventional Savonius rotor.

Evaluation of mesial root canal configuration of mandibular first molars using micro-computed tomography

Altan Şallı Gülay,Egil Edibe 대한영상치의학회 2021 Imaging Science in Dentistry Vol.51 No.4

Purpose: The aim of this study was to evaluate the root canal morphology of mesial roots of mandibular first molars. Materials and Methods: Forty extracted mandibular first molars were used in this study. The morphological examination of root canals was conducted in accordance with the Vertucci classification using micro-computed tomography (micro-CT). Any aberrant root canal configurations not included in the Vertucci classification were recorded, and their frequency was established using descriptive statistics. Intra-observer reliability was assessed using the Wilcoxon signed-rank test, while inter-observer reliability was assessed using the Cohen kappa test. Significance was evaluated at the P<0.05 level. Results: The mesial roots of mandibular first molars had canal configurations of type I (15%), type II (7.5%), type III (25%), type IV (10%), type V (2.5%), type VI (7.5%), and type VII (7.5%). The images showed 10 (25%) additional configuration types that were not included in the Vertucci classification. These types were 1-3-2-3, 1-2- 3-2-3, 2-3-1, 2-3, 1-2-3-1, 2-1-2-3, 3-2-1, 1-2-3-1, 2-3-2-3, and 1-2-1-2-1. The intra-observer differences were not statistically significant (P>0.05) and the kappa value for inter-observer agreement was found to be 0.957. Conclusion: Frequent variations were detected in mesial roots of mandibular first molars. Clinicians should take into consideration the complex structure of the root canal morphology before commencing root canal treatment procedures to prevent iatrogenic complications. Micro-CT was a highly suitable method to provide accurate 3-dimensional visualizations of root canal morphology.

터어키 政治와 9月 12月 쿠데타

Altan Kaynak 한국외국어대학교 1982 한국외국어대학교 논문집 Vol.15 No.1

Investigation of Galling In Forming Galvanized Steel Sheet

( Taylan Altan ),( Nimet Kardes ),( Hyunok Kim ) 한국부식방식학회(구 한국부식학회) 2011 Corrosion Science and Technology Vol.10 No.1

The major purpose of the present study is to evaluate the performance of various galvanized (GI) or galvannealed (GA) mild steels and AHSS in stamping applications. Finite Element Analysis (FEA) of selected stamping operations was conducted to estimate the critical pressure boundary conditions that exist in practice. Using this information, laboratory tribotests, e.g. Twist Compression (TCT), Deep Drawing (DDT) and Strip Drawing (SDT) Tests, were developed to evaluate the performance of selected lubricants and die materials/coatings in forming galvanized steels of interest. The sheet materials investigated included mild steels and AHSS (e.g. DP600 GI/GA, DP780 GI/GA, TRIP780 GA and DP980 GI/GA). Experimental results showed that galvanized material resulted in more galling, while galvannealed material showed more powdering and flaking. The surface roughness and chemical composition of galvanized sheet materials affected the severity of galling under the same testing conditions, i.e. lubricants and die materials/coatings. The results of this study helped to determine the critical interface pressure that initiates lubricant failure and galling in stamping selected galvanized sheet materials. Thus, to prevent or postpone the critical interface conditions, the results of this study can be used to select the optimum combination of galvanized sheet, die material, die coating and lubricant for forming structural automotive components.

Experimental and numerical assessment of the improvement of the load-carrying capacities of butterfly-shaped coupling components in composite structures

Gürkan Altan,Muzaffer Topçu 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.6

This study was designed to analyze the load-carrying capacities of composite structures connected face-to-face by a butterfly coupling component experimentally and numerically without adhesive. The results of the experimental studies were supported with numerical analysis. In addition, the butterfly coupling component was developed geometrically with a view to the results of the numerical and experimental studies. The change in the load-carrying capacity of the improved butterfly coupling components was analyzed numerically and experimentally to obtain new results. Half-specimens and butterfly-shaped lock components were cut with a water jet machine. Experiments and analyses were conducted to analyze the effects of coupling geometry parameters, such as the ratio of the butterfly end width to the specimen width (w/b), the ratio of the butterfly middle width to the butterfly end width (x/w), and the ratio of the butterfly half height to the specimen width (y/b). It was intended to determine the damage in the butterfly before any damage to the composite structure and to increase the service-life span of the composite structure with the repair of the butterfly lock. As a result of this study, it was determined that the geometrical fixed ratios (w/b) and (x/w) were 0.4 and 0.2 at 0.4 of (y/b) according to the experimental and numerical studies with basic and modified models.

Emotional effect of the Covid-19 pandemic on oral surgery procedures: a social media analysis

Ahmet Altan 대한치과마취과학회 2021 Journal of Dental Anesthesia and Pain Medicine Vol.21 No.3

Background: This study aimed to analyze Twitter users' emotional tendencies regarding oral surgery procedures before and after the coronavirus disease 2019 (COVID-19) pandemic worldwide. Methods: Tweets posted in English before and after the COVID-19 pandemic were included in the study. Popular tweets in 2019 were searched using the keywords "tooth removal", "tooth extraction", "dental pain", "wisdom tooth", "wisdom teeth", "oral surgery", "oral surgeon", and "OMFS". In 2020, another search was conducted by adding the words "COVID" and "corona" to the abovementioned keywords. Emotions underlying the tweets were analyzed using CrystalFeel - Multidimensional Emotion Analysis. In this analysis, we focused on four emotions: fear, anger, sadness, and joy. Results: A total of 1240 tweets, which were posted before and after the COVID-19 pandemic, were analyzed. There was a statistically significant difference between the emotions' distribution before and after the pandemic (p < 0.001). While the sense of joy decreased after the pandemic, anger and fear increased. There was a statistically significant difference between the emotional valence distributions before and after the pandemic (p < 0.001). While a negative emotion intensity was noted in 52.9% of the messages before the pandemic, it was observed in 74.3% of the messages after the pandemic. A positive emotional intensity was observed in 29.8% of the messages before the pandemic, but was seen in 10.7% of the messages after the pandemic. Conclusion: Infectious diseases, such as COVID-19, may lead to mental, emotional, and behavioral changes in people. Unpredictability, uncertainty, disease severity, misinformation, and social isolation may further increase dental anxiety and fear among people.

Evaluation of mesial root canal configuration of mandibular first molars using micro-computed tomography

Salli, Gulay Altan,Egil, Edibe Korean Academy of Oral and Maxillofacial Radiology 2021 Imaging Science in Dentistry Vol.51 No.-

Purpose: The aim of this study was to evaluate the root canal morphology of mesial roots of mandibular first molars. Materials and Methods: Forty extracted mandibular first molars were used in this study. The morphological examination of root canals was conducted in accordance with the Vertucci classification using micro-computed tomography (micro-CT). Any aberrant root canal configurations not included in the Vertucci classification were recorded, and their frequency was established using descriptive statistics. Intra-observer reliability was assessed using the Wilcoxon signed-rank test, while inter-observer reliability was assessed using the Cohen kappa test. Significance was evaluated at the P<0.05 level. Results: The mesial roots of mandibular first molars had canal configurations of type I (15%), type II (7.5%), type III (25%), type IV (10%), type V (2.5%), type VI (7.5%), and type VII (7.5%). The images showed 10 (25%) additional configuration types that were not included in the Vertucci classification. These types were 1-3-2-3, 1-2-3-2-3, 2-3-1, 2-3, 1-2-3-1, 2-1-2-3, 3-2-1, 1-2-3-1, 2-3-2-3, and 1-2-1-2-1. The intra-observer differences were not statistically significant(P>0.05) and the kappa value for inter-observer agreement was found to be 0.957. Conclusion: Frequent variations were detected in mesial roots of mandibular first molars. Clinicians should take into consideration the complex structure of the root canal morphology before commencing root canal treatment procedures to prevent iatrogenic complications. Micro-CT was a highly suitable method to provide accurate 3-dimensional visualizations of root canal morphology.