The capacity to change the lightness of discolored tooth substrates by means of minimal-invasive restorations: perception by dentists, dental technicians and laypersons

PURPOSE To evaluate the minimal ceramic thickness needed to increase the lightness by one value by means of glass-ceramic restorations perceived by dental technicians, dentists, and laypersons. MATERIAL AND METHODS A total of 15 assessment pairs (reference and test samples) were formed using glass-ceramic blocks in four different colors. Each assessment pair was comprised of two underground blocks differing in one value of lightness. On top of the underground blocks, glass-ceramic platelets were cemented in five different thicknesses (0.1 to 0.5 mm) and in the same color as the reference. Dental technicians, dentists, and laypersons (n = 41/group) were asked to determine the presence of a color difference between the two samples under standardized lighting conditions. The threshold ceramic thickness was defined as the thickness at which ≥ 50% of the evaluators were not able to perceive a difference within an assessment pair. The thresholds were analyzed, and groups were compared by applying chi-square test (P < .05). RESULTS The majority of dentists and dental technicians (> 50%) detected a lightness difference between the test and reference samples up to a ceramic thickness of 0.5 mm. The majority of laypersons (≥ 50%) did not perceive a lightness difference with ceramic thickness of 0.5 mm. If separated by the different color changes, the threshold ceramic thickness started at 0.4 mm and varied within the groups of evaluators and by the lightness of the assessed color. CONCLUSION A considerable number of evaluators perceived a lightness difference when minimally invasive ceramic restorations of 0.5-mm thickness were applied. The threshold ceramic thickness, however, was reduced when the lightness of the substrate was lower

Masking capacity of minimally invasive lithium disilicate restorations on discolored teeth-The impact of ceramic thickness, the material's translucency, and the cement color.

OBJECTIVES To evaluate minimally invasive restorations' capacity to mask discolored teeth and explore the impact of ceramic thickness, translucency, and cement color. MATERIALS AND METHODS Twenty-four assessment pairs of naturally colored and discolored bovine dentin samples were formed, using lithium disilicate specimens in six different thicknesses (0.3-0.8 mm), two different translucencies (high, low), and two cements (transparent, tooth-colored). Evaluators assessed the color differences in each assessment pair, and the threshold for detecting a color difference was determined using sequential testing and the Bonferroni-Holm method. RESULTS A thickness of 0.6 mm effectively masked color differences using high translucent ceramic with transparent cement, detectable differences were still observed at 0.7/0.8 mm. A threshold thickness of 0.4 mm was seen using high translucent ceramic and tooth-colored cement, with color differences still discernible at 0.5 and 0.8 mm. A threshold thickness of 0.4 mm was detected using low translucent ceramic and transparent cement, while detectable differences persisted at 0.5, 0.7, and 0.8 mm. A 0.5 mm threshold thickness was observed when using low translucent ceramic and tooth-colored cement, and no detectable color differences were detected beyond this thickness. CONCLUSIONS Masking can be achieved with a thickness of 0.4-0.5 mm using a low translucent material and tooth-colored cement. CLINICAL SIGNIFICANCE Understanding the impact of ceramic thickness, translucency, and cement color can aid clinicians in making informed decisions for achieving the best esthetic outcomes while preserving tooth structure. Effective masking can be accomplished with ceramic thicknesses starting at 0.4 mm, especially when employing a low translucent material and tooth-colored cement. However, clinicians should be aware that discolorations may still be detectable in certain scenarios when using minimally invasive lithium disilicate restorations

Ethical problems in an era where disasters have become a part of daily life: A qualitative study of healthcare workers in Turkey.

BACKGROUND:Natural disasters, armed conflict, migration, and epidemics today occur more frequently, causing more death, displacement of people and economic loss. Their burden on health systems and healthcare workers (HCWs) is getting heavier accordingly. The ethical problems that arise in disaster settings may be different than the ones in daily practice, and can cause preventable harm or the violation of basic human rights. Understanding the types and the determinants of ethical challenges is crucial in order to find the most benevolent action while respecting the dignity of those affected people. Considering the limited scope of studies on ethical challenges within disaster settings, we set upon conducting a qualitative study among local HCWs. METHODS:Our study was conducted in six cities of Turkey, a country where disasters are frequent, including armed conflict, terrorist attacks and a massive influx of refugees. In-depth interviews were carried out with a total of 31 HCWs working with various backgrounds and experience. Data analysis was done concurrently with ongoing interviews. RESULTS:Several fundamental elements currently hinder ethics in relief work. Attitudes of public authorities, politicians and relief organizations, the mismanagement of impromptu humanitarian action and relief and the media's mindset create ethical problems on the macro-level such as discrimination, unjust resource allocation and violation of personal rights, and can also directly cause or facilitate the emergence of problems on the micro-level. An important component which prevents humanitarian action towards victims is insufficient competence. The duty to care during epidemics and armed conflicts becomes controversial. Many participants defend a paternalistic approach related to autonomy. Confidentiality and privacy are either neglected or cannot be secured. CONCLUSION:Intervention in factors on the macro-level could have a significant effect in problem prevention. Improving guidelines and professional codes as well as educating HCWs are also areas for improvement. Also, ethical questions exposed within this study should be deliberated and actualized with universal consensus in order to guide HCWs and increase humane attitudes

Additively and subtractively manufactured implant-supported fixed dental prostheses: A systematic review

AIM To compare and report on the performance of implant-supported fixed dental prostheses (iFDPs) fabricated using additive (AM) or subtractive (SM) manufacturing. METHODS An electronic search was conducted (Medline, Embase, Cochrane Central, Epistemonikos, clinical trials registries) with a focused PICO question: In partially edentulous patients with missing single (or multiple) teeth undergoing dental implant therapy (P), do AM iFDPs (I) compared to SM iFDPs (C) result in improved clinical performance (O)? Included were studies comparing AM to SM iFDPs (randomized clinical trials, prospective/retrospective clinical studies, case series, in vitro studies). RESULTS Of 2'184 citations, no clinical study met the inclusion criteria, whereas six in vitro studies proved to be eligible. Due to the lack of clinical studies and considerable heterogeneity across the studies, no meta-analysis could be performed. AM iFDPs were made of zirconia and polymers. For SM iFDPs, zirconia, lithium disilicate, resin-modified ceramics and different types of polymer-based materials were used. Performance was evaluated by assessing marginal and internal discrepancies and mechanical properties (fracture loads, bending moments). Three of the included studies examined the marginal and internal discrepancies of interim or definitive iFDPs, while four examined mechanical properties. Based on marginal and internal discrepancies as well as the mechanical properties of AM and SM iFDPs, the studies revealed inconclusive results. CONCLUSION Despite the development of AM and the comprehensive search, there is very limited data available on the performance of AM iFDPs and their comparison to SM techniques. Therefore, the clinical performance of iFDPs by AM remains to be elucidated

An explanatory model for ethical problems in disaster settings*.

<p>* The term “Oceans of need” was quoted by Hunt [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0174162#pone.0174162.ref003" target="_blank">3</a>] from M. Michael & A.B. Zwi [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0174162#pone.0174162.ref051" target="_blank">51</a>].</p

'The Lancet' sağlıkta dönüşüm programı’nın ‘başarılarını’ Dünyaya pazarlıyor

In This essay was arranged to discuss an Article published in the Lancet on 27 June 2013, one of the longest of all Articles so far published in the journal to our knowledge, and the content of the meeting held on the same day participated by the authors of the Article and the Editor of the Lancet. The process is a sheer violation of the practice of referee that The Lancet itself envisages for its publication activities. To properly evaluate this process, the present Article first gives summaries of the Article-report, the meeting where the report was presented and supporting essays that were published in the same issue with the Article itself. The Article then makes reference to criticisms of the report either published or not in The Lancet as well as authors;amp;#8217; replies to these criticisms. It is observed that authors left most of the questions and criticisms made without any response or just ignored them saying ;amp;#8220;we could find no publication supporting this assertion.;amp;#8221; To accept the ;amp;#8220;success;amp;#8221; of the Programme for Transformation in Health in Turkey, as claimed by authors, first we have to agree that Turkey is actually a classless society and all have common interests. As is the case in other capitalist societies, the Turkish society is composed of classes and these classes have conflicting interests. Thus, contrary to the assertions of authors, the programme can be coined as ;amp;#8220;success;amp;#8221; not for all citizens but for bosses-exploiters.Bu makale, 27 Haziran 2013 tarihinde yayımlanan The Lancet’in bilebildiğimiz tarihindeki en uzun yazılardan bir tanesi ile aynı gün İstanbul’da gerçekleştirilen ve söz konusu yazının yazarları ile The Lancet Editörü’nün de konuşmacı olarak katıldığı toplantının içeriklerini tartışmak için derlenmiştir. The Lancet’in yayım faaliyeti için tanımladığı hakemlik uygulamasının ayaklar altına alındığı bu sürecin değerlendirilebilmesi için, öncelikle söz konusu yazının-raporun özeti, raporun sunulduğu toplantı ve raporla aynı sayıda yayımlanan destek yazıları özetlenmiştir. Daha sonra, rapora yönelik The Lancet’te yayımlanan ve yayımlanmayan eleştiri yazılarına yer verilmiş ve raporun yazarlarının eleştirilere yanıtı özetlenmiştir. Yazarların, kendilerine yöneltilen somut eleştiri ve soruların büyük bölümünü yanıtsız bıraktıkları ya da ‘iddiayı destekleyen bir yayın bulamadık’ ifadesiyle geçiştirdikleri izlenmiştir. Raporun yazarlarının ileri sürdüğü gibi Türkiye’de Sağlıkta Dönüşüm Programı’nı başarılı kabul edebilmemiz için Türkiye’nin sınıfsız bir toplum olduğunu ve herkesin çıkarının ortak olduğunu kabul etmemiz gerekir. Diğer kapitalist toplumlarda olduğu gibi Türkiye’de de toplum sınıflardan oluştuğu ve çıkarları birbiriyle çeliştiği için raporun yazarlarının iddialarının aksine, Sağlıkta Dönüşüm Programı toplumun bütün üyeleri için değil ancak patronlar-sömürgenler için başarılı kabul edilebilir