Zeki Akkus

Comparison of logistic regression model and classification tree: An application to postpartum depression data

In this study, it is aimed that comparing logistic regression model with classification tree method in determining social-demographic risk factors which have effected depression status of 1447 women in separate postpartum periods. In determination of risk factors, data obtained from prevalence study of postpartum depression were used. Cut-off value of postpartum depression scores that calculated was taken as 13. Social and demographic risk factors were brought up by helping of the classification tree and logistic regression model. According to optimal classification tree total of six risk factors were determined, but in logistic regression model 3 of their effect were found significantly. In addition, during the relations among risk factors in tree structure were being evaluated, in logistic regression model corrected main effects belong to risk factors were calculated. In spite of, classification success of maximal tree was found better than both optimal tree and logistic regression model, it is seen that using this tree structure in practice is very difficult. But we say that the logistic regression model and optimal tree had the lower sensitivity, possibly due to the fact that numbers of the individuals in both two groups were not equal and clinical risk factors were not considered in this study. Classification tree method gives more information with detail on diagnosis by evaluating a lot of risk factors together than logistic regression model. But making correct selection through constructed tree structures is very important to increase the success of results and to reach information which can provide appropriate explanations.

Measuring Bone Density in Healing Periapical Lesions by Using Cone Beam Computed Tomography: A Clinical Investigation

INTRODUCTION Differences in bone density before and after endodontic treatment were examined in teeth with periapical lesions in Hounsfield units (HUs) by using cone beam computed tomography (CBCT). METHODS Sixteen patients requiring endodontic treatment for periapical lesions underwent CBCT scan before and after treatment. Their bone densities were calculated in HUs. The study included 16 lesions measuring 8-10 mm in diameter. HU measurements were taken from an area of 2.25 mm(2) on the CBCT images where the bone density was lowest, before and after treatment. RESULTS The initial and final measurements were compared statistically by using paired samples statistics at the 5% significance level. CONCLUSIONS The results of this study support the use of CBCT to measure bone density before and after endodontic treatment.

Effects of lidocaine and adrenaline combination on postoperative edema and ecchymosis in rhinoplasty

Nasal osteotomies are the most important cause of periorbital edema and ecchymosis. Injection of lidocaine and adrenaline is recommended to reduce bleeding. Whilst the lidocaine and adrenaline combination (LAC) is claimed to reduce postoperative ecchymosis and edema, this effect remains to be proven conclusively. This study, on 48 patients, was designed to investigate the effects of LAC injection on postoperative edema/ecchymosis in rhinoplasty. LAC was applied at a random side prior to the lateral osteotomy. The opposite side was used as a control. The relationship between edema/ecchymosis and the degree of LAC on the injected and uninjected sides was evaluated on the first, third and seventh day postoperatively. The relationships between edema and ecchymosis with operation time and intraoperative systolic blood pressure were also evaluated. Bleeding was reduced on the side treated with LAC (p=0.050). The degrees of edema/ecchymosis increased with increases in the duration of operation and the systolic blood pressure on the first postoperative day for the LAC-applied side (p<0.05). This correlation was not observed on the opposite side (p>0.05). Application of LAC reduces bleeding during rhinoplasty and pain control postoperatively but reduced edema and ecchymosis should not be expected following LAC application.

Determination of trigeminocardiac reflex during rhinoplasty

In most rhinoplasty procedures, osteotomies are usually required. The osteotomy areas are innervated by sensory branches of the trigeminal nerve. The trigeminocardiac reflex (TCR) is clinically defined as the sudden onset of parasympathetic activity during stimulation of the trigeminal nerve. When an osteotomy is performed or external pressure is applied over the nasal bone, the infraorbital nerve may send signals via this nerve. The aim of this prospective study is to determine the blood pressure changes and occurrence of TCR during rhinoplasty. one hundred and eight patients were enrolled into the study. Lidocaine and adrenaline combination (LAC) was injected only into the left lateral osteotomy sites. All patients underwent median, right-side, then left-side lateral osteotomies and nasal pyramid infracture. The haemodynamic changes were recorded. A 10% or more decrease in the heart rate from baseline was considered a TCR. TCR was detected in nine patients following lateral osteotomies and nasal pyramid infracture procedures (8.3%). The authors determined that LAC injection prior to osteotomy did not prevent TCR. Manipulation at or near the infraorbital nerve during rhinoplasty may cause TCR, even if local anaesthetic infiltration is used.

Effects of extracorporeal shock‐wave lithotripsy on intrarenal resistive index

Objective: This prospective study was performed to determine whether extracorporeal shock‐wave lithotripsy (ESWL), widely used for treating renal and ureteral stones, affects the kidney interlobar artery resistive index (RI). Material and Methods: A total of 43 patients (30 with renal and 13 with ureteral stones) underwent color Doppler examination before and 30 min and 3 h after ESWL. Seventeen patients with renal and nine with ureteral stones underwent Doppler examination 2 weeks later. Measurements were made near the stones (nearby region), at least 2 cm from the stones (remote region) and in the contralateral kidney for renal stones, and in the ipsilateral and contralateral kidneys for ureteral stones. Results: In patients with renal stones, the RI was increased 30 min and 3 h after ESWL in the nearby and remote regions, and more markedly in the former. In the contralateral kidney, there was an increase in RI only at 3 h, which was less than that in the ipsilateral kidney. The RI at 2 weeks post‐ESWL in the nearby region and contralateral kidney did not differ from the pre‐ESWL values. ESWL performed for ureteral stones caused no increase in RI in the ipsilateral kidney. Conclusion: Patients with renal stones had a temporary increase in RI in the hours following ESWL in both the ipsilateral and contralateral kidneys, which was highest in the region near the stones and lowest in the contralateral kidney. Two weeks later, the RI in both areas had returned to pre‐ESWL levels.

Effectiveness of ethylenediaminetetraacetic acid (EDTA) and MTAD on debris and smear layer removal using a self-adjusting file

OBJECTIVE The aim of this study was to investigate the cleaning ability of a self-adjusting file (SAF) system regarding debris and smear layer removal using ethylenediaminetetraacetic acid (EDTA) or MTAD. STUDY DESIGN In total, 45 maxillary incisor teeth were randomly divided into 2 different irrigation groups of 20 canals each and a negative control group of 5 canals. The canals in each of the irrigation groups were irrigated using sodium hypochlorite (1.3%) as an initial irrigant during the first 2 minutes of operation, followed by 2 minutes continuous irrigation with either 17% EDTA or MTAD in a closed system. The negative control group was irrigated using 1.3% sodium hypochlorite. The roots were split longitudinally and subjected to scanning electron microscopy (SEM). The presence of debris and smear layer in the coronal, middle, and apical thirds of the canal was evaluated using a 5-grade scoring system with ×200 and ×2,000 magnification, respectively. RESULTS The SAF operation with 2-minute continuous irrigation using MTAD resulted in root canal walls that were free of smear layer in 85%, 70%, and 60% and of debris in 95%, 90%, and 95% of the coronal, middle, and apical thirds of the root canals, respectively. The SAF operation with continuous irrigation using EDTA resulted in root canal walls that were free of smear layer in 85%, 60%, and 50% and of debris in 95%, 90%, and 85% of the coronal, middle, and apical thirds of the root canals, respectively. Teeth in the negative control group were totally covered with debris. Evaluation by SEM showed no significant difference between the tested irrigants in removing the smear layer and debris among the different regions of the root canal. Both groups were significantly different from the negative control group. CONCLUSIONS When using the SAF, the protocols used in this study were effective for debridement for all regions of the root canal even for the apical thirds.

Patient-specific factors in the proximity of the inferior alveolar nerve to the tooth apex.

Objectives: To evaluate whether age and gender differences are predictive factors for inferior alveolar nerve position with respect to mandibular first molar roots. Study Design: Cone-beam computed tomography scans [0.2-mm3 voxel size; n = 200 (100 males, 100 females)] of patients aged 15–65 years showing mandibular first and second molars were included in this study. Patients with pathoses that might affect inferior alveolar nerve position, including second molar and/or first premolar extraction, were excluded. Fourteen measurements (mm) were taken from the inferior alveolar nerve to the mesial and distal root apices. Subjects were grouped by age and gender. Data were analysed using two-way analyses of variance with post hoc Bonferroni corrections. Results: The distance from the inferior alveolar nerve to the root apices was smaller in females than males, regardless of age (p < 0.01). Distal roots were closer to the nerve than mesial roots in both genders (p < 0.05). Total buccolingual mandibular length (at 3-mm apical level) was shorter in females than males (p < 0.01) but mean buccolingual mandibular width at the level of the inferior alveolar canal did not differ. Nerve–root apex distances were significantly shorter in males and females aged 16–25 and 56–65 years than in other age groups (p < 0.01). Conclusions: The distance between inferior alveolar nerve and mandibular first molar roots depends upon the age and gender: it is shorter in females than in males and in subjects aged 16–25 years and >55 years than in other age groups. Key words:Age, cone-beam computed tomography, inferior alveolar nerve, root apex, gender.

A Comparison of Microleakage Scores of Five Different Types of Composite Resins

ABSTRACT This study aimed to perform a comparative assessment of microleakage in Class V cavities among five different composite resins. For this purpose 100 fresh caries-free human permanent molars were randomly assigned to one of five groups (n=20). Clearfil Majesty Esthetic + Clearfil S3 Bond (Group I), TPH Spectrum + Xeno V (Group II), Gradia Direct Anterior + G Bond (GC) (Group III), Premise + Optibond All in One (Group IV) and Charisma + iBond (Group V) were applied and polymerized under LED. Specimens were varnished, immersed in 0.5% methylene and sectioned bucco-palatinally/lingually, and microleakage scores were determined. Gingival and occlusal microleakage scores among groups were statistically significant (p<0.05) (p=0.043, p=0.005). Occlusal microleakage scores for Clearfil Majesty Esthetic and Premise were lower than in the other groups. Charisma had the highest microleakage scores, with no difference among the other groups (p>0.05). In conclusion occlusal and gingival microleakage scores were satisfactory except for Charisma.

The effecTs of exTreMly low frequency MagneTIc fIeld and Mangan To The oral TIssues

ABSTRACT Exposure to extremely low frequency magnetic field (ELFMF) originating from daily electrical-electronic appliances and electric lines, is a common thing. Recently, the discussions focused on the topic whether ELFMF had any harmful effects over health or not. Several previous studies displayed that ELFMF significantly increased bone mineral density. The aim of the present study was to investigate the influence of ELFMF and manganese over mineral accumulation in head and jaw bones of rats. Previous studies showed that manganese plays a significant role over normal development of enamel and dentin alongside contributing to the calcium and phosphorus association. In the present study, the effects of exposure to ELFMF and manganese on mineral density and histology of teeth, were investigated. In the present study, 64 male Wistar albino rats were divided into 8 groups. Amount of mineral elevations were determined in head and jaw bones of the first 6 groups (p<.05) and histologic alterations were found in teeth of rats. The obtained results indicated that ELFMF plays an important role over mineral density and histologic structure of cranial and jaw bones in rats. In conclusion, further epidemiological and experimental laboratory studies are required for more detailed evaluation of the effects of ELFMF on cranial and jaw bones of rats.

Effect of electromagnetic fields and antioxidants on the trace element content of rat teeth

The purpose of this study was to examine the possible effect of extremely low-frequency electromagnetic fields (ELF-EMFs), from a high-voltage source, on rat teeth in terms of changes in trace elements (TEs) and the effect of antioxidants (melatonin [MLT] and Ganoderma lucidum [GL]) in counteracting these effects. We used adult male Wistar albino rats with a mean weight of 250–300 g and divided the rats into eight groups. The groups were subjected to an ELF-EMF that was applied with a high-voltage line for 8 hours/day for 26 days (Groups I, II, and III) or 52 days (Groups V, VI, and VII). Groups IV and VIII were the 26- and 52-day control/sham groups, respectively. Groups II and VI were treated with GL, and Groups III and VII were treated with MLT. MLT and GL were administered daily based on the weight of the animals and appropriate standards. At the end of the study, the rats were euthanized, and their anterior teeth were extracted. The teeth were preserved in pure water before evaluating the major TEs. At the end of the study, TE concentrations (in mg/kg) were assessed in the control and test groups. Compared with Group V, statistically significant differences in the concentrations of zinc (Zn) and strontium (Sr) were found for Group VII (ELF-EMF + MLT) (P<0.05). Therefore, ELF-EMF exposure can change the content of certain TEs in teeth and, after administering MLT and GL, the values of some of the TEs return to normal.