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    COMPARISON OF SUBJECTIVE ESTHETIC PERCEPTIONS OF DENTISTS WITH DIFFERENT GENDER AND CLINICAL EXPERIENCES WITH OBJECTIVE DENTOLABIAL ESTHETIC MEASUREMENTS
    (2020) Geduk, Şükriye Ece; Şahin, Onur; Velioğlu, Neslin
    Objective: This study aimed to evaluate the consistency of specific measurable dentolabial criteria between the esthetic values accepted in the literature and the subjective opinions of physicians. Materials and Methods: Four associate professors and four research assistants in the field of prosthodontics were selected as the examiners in the study. Photographs of smiles (focusing on the mouth region of the face) taken from 200 volunteers were examined. The results of the objective measurements of the curvature of the incisal edge and lower lip parallelism, the incisal edge and lower lip contact, the laugh line, the buccal corridor and the interincisal line and midline variables, and the subjective assessments of the evaluators were compared using Cochran’s Q test. Results: Esthetic perception is subjective; however, there was a significant correlation between the objective measurements and subjective perceptions in the incisal edge and lower lip parallelism, laugh line, and buccal corridor variables. No statistically significant difference was found between the objective computer measurements and the evaluations of the male and female examiners or between the perceptions of the specialists (associate professors) and the research assistants. Conclusion: There is no consensus between esthetically objective findings and subjective perceptions.
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    Performance of polyether ether ketone (peek) for dental applications: surface roughness and color stability
    (2022) Erdağ, Ümmü Habibe; Şahin, Onur; Köroğlu, Ayşegül; Özdemir, Tonguç; Dede, Doğu Ömür
    Polymeric materials are inevitably used in dental applications. Dental prostheses are cleaned during their service life, and surface roughness is an important criterion for these polymeric materials. In this study, the efect of diferent denture cleaning methods on the surface roughness and color stability of polyether ether ketone (PEEK) dental materials was studied. Seventy disk-shaped (10×3 mm) specimens were fabricated and divided into seven groups (n=10) according to the cleaning procedure. One of these groups subjected to distilled water was the control group. Other three groups were subjected to daily cleansing with denture cleaners (5% sodium hypochlorite, alkaline peroxide, chlorhexidine gluconate solution) and the other three groups were subjected to mechanical cleaning with a toothbrush with three diferent dentifrices (toothpaste, soap, and denture cleansing gel). The surface roughness values (Ra) were measured with a proflometer before (Ra0) and after cleaning procedures for 270 days (Ra1). CIELab color parameters of each specimen were measured with a spectrophotometer before and after 7 days of storage in a coffee solution. Color diferences were calculated, and data were statistically analyzed with one-way ANOVA and the Tukey HSD test (?=.05). For all test groups, Ra0 and Ra1 values were lower than the plaque accumulation threshold level (PATL) of 0.200 ?m. For both Ra and ?E00 values, the efect of the cleaning method was not statistically signifcant (P>0.05). Also, no signifcant diference was observed for Ra0, Ra1, and ?E00 values between the test groups (P>.05). It was concluded that considering the color stability and surface roughness, many cleaning procedures can be used safely for PEEK polymers.
  • Küçük Resim
    Öğe
    Surface roughness and Streptococcus mutans adhesion on surface sealant agent coupled interim crown materials after dynamic loading
    (2022) Eşlemez Topçu, Eda; Şahin, Onur; Köroğlu, Ayşegül; Cömert, Füsun; Yılmaz, Burak
    Background: With the application of surface sealant agents, smooth surfaces can be achieved in a shorter time when compared with conventional polishing. However, studies on the performance of these agents against chewing forces are not many. The purpose of this study was to evaluate the surface roughness and Streptococcus mutans adhesion on surface sealent coupled interim prosthetic materials after chewing simulation. Methods: One hundred and twelve specimens were fabricated from two poly(methyl methacrylate) (Tab 2000, Dentalon Plus) and two bis-acryl (Tempoft, Protemp 4) interim crown materials and divided into 4 groups (n=7) according to applied surface treatment: conventional polishing (control) and 3 surface sealant (Palaseal, Optiglaze, Biscover) coupling methods. The surface roughness values (Ra) were measured with a proflometer before (Ra0) and after aging through dynamic loading in a multifunctional chewing simulator for 10,000 cycles at 50 N load combined with integral thermocycling (between 5 and 55 °C) (Ra1). Specimens were incubated with Streptococcus mutans suspension and the total number of adherent bacteria was calculated by multiplying the counted bacterial colonies with the dilution coefcient. Results: Surface sealant agent application signifcantly decreased the surface roughness compared with conventionally polished specimens, except for Optiglaze or BisCover LV applied Protemp 4 and Palaseal or Biscover LV applied Tempoft. Surface roughness after dynamic loading showed a statistically signifcant increase in all groups, except for the control groups of Tab 2000 and Protemp 4. A positive correlation was found between surface roughness values of interim prosthodontic materials and the quantitiy of Streptococcus Mutans. Conclusions: Even though surface sealant agent application signifcantly decreased the surface roughness compared with conventionally polished specimens, dynamic loading signifcantly increased the surface roughness of all surface sealant coupled materials. The Ra values of all test groups were higher than the plaque accumulation threshold (0.20 µm). Streptococcus mutans adhered more on rougher surfaces