INTRODUCTION: This study aimed to compare the cyclic fatigue resistance of Hyflex EDM and WaveOne Gold rotary instruments in simulated abrupt apical curvature at body temperature.
METHODS: A total of 10 Hyflex EDM OneFile (25/04-08) and 10 WaveOne Gold Primary (25/07) instruments free of visible defects were selected after inspection. Instruments were tested in an artificial canal having an angle of curvature of 90° and a radius of curvature of 2 mm. The instruments were rotated at speed and torque values recommended by manufacturers at 37°C until fracture occurred. Time required for fracture (TF) was recorded with a 1/100 s digital chronometer. The TF and fractured fragment length data were statistically analyzed using t-test with significance threshold of 5%.
RESULTS: The mean TF value was 98.40 ± 19.93 seconds for WaveOne Gold group and 183.50 ± 35.33 seconds for Hyflex EDM group. Hyflex EDM OneFile instruments fractured in a longer time period than WaveOne Gold instruments and the difference between them was statistically significant (p<0.05).
DISCUSSION AND CONCLUSION: Hyflex EDM OneFile instruments, which are produced with electric discharge machining, were found to be more resistant to cyclic fatigue than WaveOne Gold instruments.

INTRODUCTION: This study aims to evaluate the effects of ozone on color parameters of the Munsell color system in comparison with hydrogen peroxide.
METHODS: Twenty-four samples were prepared from the buccal surfaces of bovine maxillary incisors. The initial color of the samples was measured with a spectrophotometer. All samples were incubated for 45hours in a discoloration solution containing instant coffee. Color measurements were repeated. The samples were randomly divided into two groups (n=12). Bleaching procedures were carried out using office-type bleaching material containing 35% hydrogen peroxide and a dental ozone generator has a special bleaching setting capable of producing 600 ppm ozone gas. Color measurements were repeated. ΔE, ΔL *, Δa *, and Δb were calculated from L*, a* and b* values. Statistical evaluation was performed with Shapiro-Wilk, Levene, Friedman, and Mann Whitney U tests (p <0.01).
RESULTS: Both bleaching materials provided effective bleaching (ΔE> 3.7). Among the bleaching groups, a statistically significant difference was found between ΔL * and ΔE (p <0.01), while Δa * and Δb * values were statistically similar (p = 0.950, p=0,080).
DISCUSSION AND CONCLUSION: Ozone gas provided effective bleaching and changed b* value, the most important parameter in the perception of the tooth color whiter, similar to hydrogen peroxide.

INTRODUCTION: The aim of this study was to evaluate the oral-dental health knowledge, attitudes and behaviors of the doctors working in the emergency medicine, pediatric services and family health centers.
METHODS: The data were obtained through a face-to-face questionnaire applied to 85 doctors. The questionnaire form was composed of three sections including demographic information, questions measuring attitudes and behaviours related to oral-dental health, and information about oral health. Descriptive statistical analysis and Chi-Square test were used.
RESULTS: It was determined that 90.6% of the doctors who participated in this study did not receive information about oral-dental health before and 80% did not consider their knowledge about oral-dental health sufficient. A statistically significant relationship was observed between the doctors who thought that caries in the decidious teeth should be treated (p=0.01) and doctors who thought that children should start dental cleaning from birth (p=0.045) and their specialties. In addition, the relationship between doctors who thought that an avulsed tooth should be found and their specialties was found to be statistically significant (p=0.002).
DISCUSSION AND CONCLUSION: It is thought that it would be beneficial to include the oral-dental health issues in the medical education curriculum of the doctors who play an important role in oral and dental health.

INTRODUCTION: The purpose of this study was to compare the effects of the insertion angle of implants on stress distributions in implants of maxillar implant-supported zirconia-ceramic crowns.
METHODS: For comparison, vertical and oblique loading forces were used. Three-dimensional finite-element implant models of a maxillar section of bone with missing first molars and their zirconia-ceramic crowns were used. Dental implants of 10 mm in length, 3.7 mm in diameter were modelled. A load of 300 N was applied toward vertical and oblique (30o to the vertical) directions. Maximum and minimum von Mises stress values of the implants were calculated.
RESULTS: The highest stress value was concentrated in the zirconia framework of the maxilla 45o angled implant-supported zirconia-ceramic crown model with the oblique loading force (663,83 MPa). The stress values 45o angled implant-supported models were higher than other angled implant models (vertical and 15o angled). Stress values with oblique loading forces were higher than with vertical loading forces.
DISCUSSION AND CONCLUSION: As the angle of placement of the implants in the maxilla increases, stresses increase both in the neck of the implants and in the cervical of the implant-supported zirconia-ceramic crowns.

INTRODUCTION: The aim of the study was to evaluate the applicability and accuracy of age estimation using Willems method in Turkish children from the Aegeon region and to analyze the reliability of this method in different age groups for both genders.
METHODS: Panoramic radiographs of 2000 children (1000 females, 1000 males) aged between 5 and 15 years were examined by one observer. This retrospective study involved a contemporary aegean Turkish population. The chronological ages of the subjects were divided into 11 groups. These 11 groups consisted of children of the following ages 5 and 15. The paired t-test was used to compare all data according to gender and age groups.
RESULTS: No statistically significant difference was present between Williems method, Demirjiyan method and chronologic age in all ages groups (p>0.05).
DISCUSSION AND CONCLUSION: In conclusion, Williems method is suggested for age estimation in the pediatric population because it is easy to use and it has similar results compared to the chronologic age.

INTRODUCTION: The aim of this study was to compare the radiopacities of four different root canal files and gutta-percha with digital radiographic technique and energy dispersion X-ray spectrometry.
METHODS: Reciproc, Reciproc Blue, Protaper and stainless steel files and gutta-percha cone were used.Digital radiographic images of specimens were obtained under standard exposure conditions.In addition, the chemical contents of the test groups were determined by energy dispersive X-ray spectrometry analysis.The relationship between the contents of the materials and the radiopacity values was evaluated. The data were compared statistically using One-way ANOVA and post-hoc Tukey analysis(p=0.05).
RESULTS: The radiopacity values of the samples were determined as Stainless steel file, Reciproc Blue, Protaper and gutta-percha from the highest to the least, and it was observed that they had radioopacity values compatible with the nickel, titanium, iron and zinc ratios in their contents. It was revealed that there was no statistical difference between the radiopacity values of Reciproc, Reciproc Blue, Protaper, and stainless steel files(p>0.05).The difference between all file groups and gutta-percha was found to be statistically significant(p<0.05).
DISCUSSION AND CONCLUSION: It was determined that the radiopacity values of all the materials were above the minimum standard values recommended by the International Standards Organization(ISO) and the American National Standards Institute(ANSIADA).

INTRODUCTION: The aim of this study was to identify endodontic prediagnoses and referral reasons for Cone Beam Computed Tomography (CBCT) examinations, and to determine the radiological confirmation rate on archived CBCT reports.
METHODS: Radiological reports from CBCT examinations performed between January 01-December 31, 2019 were scanned through the archives. CBCT examination that were requested by endodontists were identified and endodontic prediagnoses were recorded for each examination. The distribution of endodontic prediagnoses was analyzed using descriptive methods. The radiological confirmation rate between endodontic prediagnoses and radiological diagnosis was calculated using Wilson’s method with 95% confidence interval.
RESULTS: A total of 4325 CBCT reports were included. Among these 329 CBCT examinations (7.60%) were performed for the diagnosis of endodontic pathologies. The most common reasons for CBCT referral were examination of apical lesion (39.36%), root canal morphology (22,22%) and vertical fracture (20.63%). Internal root resorption was the highest radiologically confirmed pathology, while confirmation rate for vertical fracture was the lowest. The overall radiological confirmation rate for endodontic prediagnoses was calculated as 55%.
DISCUSSION AND CONCLUSION: According to our results a prediagnosis of internal root resorption is commonly confirmed by CBCT, while the radiological confirmation rate for suspected vertical root fracture is low.

INTRODUCTION: Evaluation the effect of prophylactic polishing protocols on the surface roughness of different resin composites.
METHODS: Three different resin composites were used: nanohybrid(Charisma Topaz-CT), high-viscosity bulk-fill(Filtek Bulk Fill-FB) and low-viscosity bulk-fill(Metafil Bulk Fill-MB)(N=40). Totally 120 disc-shaped specimens(diameter: 4mm,thickness: 2mm) were fabricated and polymerized with LED light-curing device for 20s(1000 mW/cm2). The polishing procedures were performed with aluminum oxide discs (OptiDisc) and randomly subdivided into four groups according to different prophylactic polishing protocols(n=10): 1)control(no prophylactic polishing protocol), 2)polishing paste, 3)air-polishing, 4)air-polishing+polishing paste. The surface roughness(Ra,μm) were measured by a contact profilometry(Marsurf M 300C). Data were statistically analyzed with two-way ANOVA and Bonferroni tests(p<0.05).
RESULTS: Regarding the polishing protocols, for MB and CT, control and polishing paste groups showed significantly lower surface roughness than air-polishing and air-polishing+polishing paste groups. For FB, polishing paste group showed significantly lower surface roughness than air-polishing group. Regarding the resin composites, for control group, CT showed significantly lower surface roughness than MB and FB. For all prophylactic polishing protocols, CT showed significantly lower surface roughness than MB(p<0.05).
DISCUSSION AND CONCLUSION: Air-polishing caused higher surface roughness than polishing paste for all tested composites. Besides, low-viscosity bulk-fill showed higher surface roughness than nanohybrid composite for all prophylactic polishing protocols.

Halitosis describes unfavourable/unacceptable odour in the expired air originating from both intra-oral and extra-oral causes. Individuals with bad breath suffer social anxiety which eventually leads to poor oral health-related quality of life. Besides its adverse impacts on psychology and social aspects, halitosis can also be an indicator of severe systemic diseases. A new standardized and etiology-based classification system has been proposed recently to overcome drawbacks of former classification systems such as non-standardized typing and lack of specific description for different types of halitosis. The aim of this article is to present current classification system and etiological factors for halitosis, along with diagnostic methods and therapeutic approaches.