1,720,992 research outputs found
Evaluation of the clinical success of class I cavities prepared by an Er:YAG laser-5-year follow-up study
No full textHamidi, Mehmet Mustafa/0000-0003-3461-7925; Colak, Hakan/0000-0001-8262-0913; ERCAN, Ertugrul/0000-0002-4753-6553The purpose of this study was to evaluate, after 5 years, the clinical success of preparing class 1 composite resin restorations with an Er:YAG laser. Sixty-five teeth of 30 patients were included in the study, and an Er:YAG laser emitting at a wavelength of 2.94 mu m was used for the class I cavity preparations with not more than one third of the mesiodistal width of the occlusal surfaces of each tooth. All cavities were restored with a light-cured composite resin, following a single bond application. After the baseline examination, restorations were reevaluated by the same experienced clinician after 5 years, using the modified Ryge criteria. At the end of 5 years, 41 of the 65 restorations were evaluated in 22 patients and scored. With respect to marginal discoloration, anatomic form, color match, and surface texture, significant differences were found between baselines tested after 5 years. Clinical evaluation of postoperative sensitivity showed that 90.2 % were rated as alpha. All restorations evaluated in this study demonstrated acceptable clinical performance within the evaluation period based on the alpha and bravo ratings for clinically satisfactory restorations. Further evaluations are necessary for a better clinical performance analysis
One-year clinical evaluation of different types of bulk-fill composites
No full textColak, Hakan/0000-0001-8262-0913; Bayraktar, Yusuf/0000-0001-6250-5651; Hamidi, Mehmet Mustafa/0000-0003-3461-7925; ERCAN, Ertugrul/0000-0002-4753-6553Aim: In the present study, we evaluated the 1-year clinical performance of a conventional posterior composite resin and three bulk-fill composite resins. Methods: Fifty patients with four class II restorations under occlusion were enrolled in the present study. A total of 200 restorations were placed in the cavity, 50 for each material (Clearfil Photo Posterior, Filtek Bulk-Fill Flowable and Filtek P60, Tetric EvoCeram Bulk-Fill, and SonicFill). One operator placed the restorations in the cavity, and 1 week later the patients were called for baseline examination. Two calibrated examiners evaluated the restorations once every 3 months for 1 year, according to United States Public Health Service criteria. The data were analyzed using SPSS. Non-parametric tests (Kruskal-Wallis, Mann-Whitney U-test, and Friedman) were used for the analysis at a confidence level of 95%. Results: The 1-year recall rate was 86%. All restorations showed minor modifications after 1 year. However, no statistically-significant differences were detected between the materials' performance at baseline and after 1 year for all criteria (P > 0.05). Conclusions: The bulk-fill composite resin materials showed similar clinical performance when compared with a conventional posterior composite resin. Further evaluations are necessary for the long-term clinical performance of these materials
Analysis of Endodontic Complications Following Fixed Prosthodontic Rehabilitation
No full textColak, Hakan/0000-0001-8262-0913Purpose: The aim of this study was to determine endodontic treatment needs and types of endodontic disease following fixed prosthodontic treatment 24 hours after tooth preparation, 1 week after tooth preparation, 1 month after placement, and 6 months after placement. Materials and Methods: Study groups consisted of patients who attended a university dental hospital department of prosthodontics for fixed prosthodontic treatment from January 2011 to December 2013. All teeth were clinically and radiographically evaluated according to American Association of Endodontists evaluation criteria before preparation. Metal-ceramic fixed partial dentures were placed for all patients. A total of 1,633 abutment teeth were prepared with 1,100 pontics in 524 patients (214 female and 310 male). Participant age, sex, and tooth number were recorded. Endodontic treatment follow-up was scheduled for 24 hours after tooth preparation, 1 week after preparation, 1 month after placement, and 6 months after placement, and all teeth were evaluated after placement of FPDs according to a modified criteria. Results: 2,733 retainers were placed with 624 FPDs. Of the FPDs, 332 (53%) were placed in the posterior and 196 (31.5%) in the anterior region. The remaining 96 FPDs (15.5%) were placed anteroposterior. The abutment/pontic ratio was 1.44:1. The number of retainers per FPD was 4.37. Of 1,633 abutment teeth, 103 were endodontically treated after placement of FPDs. Most observed endodontic disease was symptomatic irreversible pulpitis. There were statistically significant differences in terms of teeth regions (P .05). Conclusion: A total of 2,733 retainers on 624 FPDs were evaluated over 6 months, and the mean endodontic treatment need ratio was 6.3%
Evaluation of Novel Microabrasion Paste as a Dental Bleaching Material and Effects on Enamel Surface
No full textColak, Hakan/0000-0001-8262-0913; Hamidi, Mehmet Mustafa/0000-0003-3461-7925Purpose: Dental fluorosis is an enamel dysplasia that can cause serious aesthetic and psychological problems. An examination of the literature shows that the microabrasion method is the most effective way to treat fluorosis. This study aimed to produce a prototype microabrasion paste for the treatment of fluorosis stains and to examine the effects of the paste on tooth structure and color in vitro. Material and Methods: Forty extracted upper incisor teeth were used in this study. The teeth were divided into four treatment groups: a prototype microabrasion paste group (N = 10), an Opalustre paste group (N = 10), a 37% phosphoric acid gel group (N = 10), and a distilled water (control) group (N = 10). Following treatment, all specimens in each of the four groups were examined by scanning electron microscopy for changes in their surface enamel. Changes in tooth color changes of the 1st and 2nd groups were measured before and after treatment by a VITA Easyshade Advance spectrophotometer. Results: In scanning electron microscopy evaluations, significant differences were not observed between the 1st and 2nd groups. Differences in three color-measuring coordinates between the 1st and 2nd were also not statistically significant (p > 0.05). Conclusions: The study demonstrated that the prototype paste is a viable treatment option for dental fluorosis. CLINICAL SIGNIFICANCE The findings in this study demonstrated that the tested prototype microabrasion paste is extremely harmless, minimally invasive agent, and able to improve the color, shine and chrome values of the teeth
A Survey on Prevalence, Causes and Prevention of Post-cementation Hypersensitivity
No full textColak, Hakan/0000-0001-8262-0913; Ozcan, Mutlu/0000-0002-9623-6098This study evaluated the prevalence and causes of post-cementation sensitivity and possible prevention measures according to the experience of dentists through an inter-net survey. A questionnaire was prepared with 25 items based on a survey introduced by Rosenstiel and Rashid. An online site was created for the participation to the survey. A total of 322 participants responded the questionnaire. The results of the questionnaire indicated the amount of tooth preparation (42.1%) is the most frequent reason for hypersensitivity followed by water-cooling with pressure (11.2%) and provisionals (10.9%). "Very important" response for tooth reduction, time before cementation, overheating, luting agent, occlusion and provisionals were found to be of statistical significance (p<0.001). Comparing respondents' opinions the incidence of post-cementation sensitivity appears to be underestimated. Tooth reduction, preparation under high volume spray and quality of provisional restorations was considered to have a significant impact on the incidence of post-cementation sensitivity according to the dentists surveyed across Turkey. Respondents to the questionnaire considered the use of antimicrobial, desensitizing, resin bonding, hemostatic agents, varnishes, type of liner material, rotary instruments to be less effective for prevention of post-cementation sensitivity
The effect of different adhesives and setting times on bond strength between Biodentine and composite
No full textColak, Hakan/0000-0001-8262-0913; Hamidi, Mehmet Mustafa/0000-0003-3461-7925; ERCAN, Ertugrul/0000-0002-4753-6553Background: The aim of this study was to evaluate the effects of 3 different adhesives with different functional monomers, on the shear bond strength (SBS) of Biodentine (R). Methods: Acrylic blocks (n = 90) were prepared and a 2-mm height x 4-mm diameter hole was opened in each block. Every hole was completely restored with Biodentine (R). Before preparation of composite restorations over the Biodentine (R) (2-mm height x 2-mm diameter), 3 different adhesives (Etch-37 (37%) w/BAC by Bisco & Prime Bond N&T, Clearfil S-3 Bond and Adper Prompt L-Pop) were applied. SBS was evaluated using a universal testing machine, and failure mode for each sample was recorded. The results were statistically analyzed using 2-way ANOVA and post hoc Tukey test. Results: When the megapascal values of all groups were compared, although there was no statistically significant difference in the different setting times (p>0.05), statistically significant differences were observed among all adhesive groups (p<0.05). Moreover, the highest SBS values were observed in the Clearfil S-3 Bond group. Conclusions: Clinical performance of Biodentine (R) may be affected by adhesive procedures and its setting time
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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