Construction of a copper stepwedge with aluminum equivalent mean gray values

OBJECTIVES: To produce a copper (Cu) stepwedge with aluminum (Al) equivalent mean gray values (MGV). MATERIAL AND METHODS: The thicknesses of Cu steps that were equivalent to those of the Al were formulated using the X-ray attenuation properties of the materials. The Al and fabricated Cu stepwedges were radiographed, but the MGVs of the Cu stepwedge were mismatching to those of the Al. Using a mathematical function to adjust the pixel MGV of Cu stepwedge to those of the Al, new Cu stepwedges were created. In vitro iterations were performed until best approximation to Al was reached. RESULTS: The MGV of the Cu stepwedges fabricated by formularization were different than those of Al (p=0.001). Iteration method led to MGV similar to those of the Al stepwedge (p=0.207). CONCLUSIONS: Construction of a Cu stepwedge according to the basic rules of radiophysic failed to result in a stepwedge with similar radiodensity values to those of Al stepwedge. Further studies may use the formularization method only for prototype Cu wedge production, but consecutive iterations shall be compassed to obtain the best approximation to Al MGV

Amputation of an Extra-root with an Endodontic Lesion in an Invaginated Vital Maxillary Lateral Incisor: A Rare Case with Seven-year Follow-up

The developmental abnormality of tooth resulting from the infolding of enamel/dentin into the root is called dens invaginatus. Management of such cases is usually challenging due to the morphological complexity of root canal system. This report presents a rare treatment protocol of a clinical case of Oehler’s type III dens invaginatus combined with an endodontic lesion in a vital maxillary lateral incisor. Access to the endodontic lesion located between the central and lateral incisors was achieved by reflection of a full mucoperiosteal flap. Granulomatous tissue as well as aberrant root was removed and the surface of the root and adjacent coronal region were reshaped. Three years later, the patient was orthodontically treated. Seven years after completion of surgical/orthodontic management, the tooth remained asymptomatic and functional with normal periodontium/vital pulp. Radiographically, the healing of the lesion was observed. Actually, vitality of the invaginated tooth and communication between the invagination and the root canal were the most important factors in determining such minimally invasive treatment protocol. Depending on the anatomy of the root canal system, surgical amputation of an invaginated root can be performed to achieve a successful outcome in Oehler’s type III dens invaginatus cases, even though it is associated with apical periodontitis.Keywords: Apical Periodontitis; Dens Invaginatus; Endodontic Therapy; Lateral Incisor; Periradicular Surger

Impact of internet supported dental education: Initial outcomes in a study sample

The aim of this preliminary mixed method study was to understand dental students’ thoughts on internet supported learning environment (ISLE) and to investigate its’ impact on their academic success. The research was designed to enroll the students from the 7th semester of School of Dentistry. The lecturer taught dental students for four hours (within four weeks) on the topics of "anamnesis, extraoral and intraoral examination". Voluntary twenty-four students participated actively to the ISLE. During the evaluation phase, data were collected by using open-ended questionnaire, instructor’s observation, students’ evaluation forms and exam results. According to the Open-ended questionnaire, 90% of the participating students mentioned e-learning experience positively affected their success; 55% of the students stated that dental courses can be taught online. According to students’ evaluation form, the highest mean score was granted to the instructor of the course (4.6/5), followed by the learning environment (4.1/5) and the materials (3.7/5). There was a significant difference between the grades granted to the instructor and materials; students thought the instructor was more important than the teaching materials (p<0.05). It was concluded that ISLE supported by PBL increased the students’ satisfaction, positive learning environment and academic success

Farklı post materyallerinin radyoopasitelerinin değerlendirilmesi

Amaç: Dört farklı post materyalinin radyoopasitelerinin karşılaştırılmalı olarak değerlendirilmesidir.Gereç ve Yöntem: CosmoPost (Ivoclar Vivadent, Leicester, İngiltere), Unicore (Ultradent, Salt Lake City, CA, ABD), D.T.Light-Post (Bisco Inc, Schaumburg, IL ABD), FRC Postec Post (Ivoclar Vivadent, Schaan, Liechtenstein) sistemlerine ait farklı serilerden seçilen postlardan, düşük hızda dönen elmas separe yardımıyla 2 mm kalınlığında sekizer tane örnek elde edildi. Her markaya ait birer örnek ve referans kabul edilen %99 saflıkta alüminyum step wedge ile birlikte fosfor plak üzerinde konumlandırılıp standart dijital radyografiler alındı. TIFF formatında kaydedilen görüntüler, görüntü analiz programıyla değerlendirildi ve her örneğin ortalama grilik değerleri tespit edildi. Veriler tek yönlü varyans analizi ve Tukey çoklu karşılaştırma testleri kullanılarak olarak analiz edildi (p=0,05).Bulgular: En yüksek radyoopasite değeri Cosmopost (7,37± 0,17 mm Al) için saptandı. Bu materyali sırasıyla Unicore (4,3±0,26 mmAl), D.T.Light-Post (2,11±0,1 mmAl) ve FRC Postec (1,72±0,24 mmAl)  izledi (p< 0,05). Sonuçlar: D.T.Light Post’un Al’a yakın bir radyoopasiteye sahip olduğu, diğer materyallerin radyoopasite özelliklerinin ise Al’den ve dolayısıyla dentinden daha yüksek veya düşük olduğu belirlendi

Intraoral premalign ve malign lezyonlu hastaların doku örneklerindeki candida türlerinin DNA analiziyle belirlenmesi ve sağlıklı doku ile karşılaştırılması

Amaç: Bu retrospektif çalışmada premalign ve malign lezyonlu ile sağlıklı bireylere ait doku örneklerindeki Candida albicans, Candida kruseii, Candida parapsilosis, Candida tropicalis ve Candida glabrata türlerinin belirlenmesi amaçlanmıştır.  Gereç ve Yöntem: Çalışmaya oral premalign veya malign lezyon şüphesi nedeniyle biyopsi uygulanmış doku örnekleri dahil edildi. Örnekler histolojik özelliklerine göre sağlıklı (n=20), displazi (n=20), karsinoma in-situ (n=20) ve skuamoz hücreli karsinom (SHK) (n=20) olmak üzere 4 gruba ayrıldı. DNA izolasyonunun ardından Candida türlerine ait DNA örneklerinin miktar ve saflık kontrolleri gerçekleştirildi. Kantitatif ölçümler için Real-Time PCR (LightCycler 96, Almanya) kullanıldı ve standart eğriler hesaplandı. Veriler Mann-Whitney ve Wilcoxon Signed Ranks testleri ile değerlendirildi (P<0.05).Bulgular: Sağlıklı ve displazik örneklerin yer aldığı gruplarda C. parapsilosis (104DNA/50 mg) en sık görülen Candida türüydü. Karsinoma in-situ grubunda C. tropicalis ve C. kruseii (103DNA/50 mg), SHK grubunda ise C. kruseii (104DNA/50 mg) seviyelerinin daha yüksek olduğu belirlendi. Örneklerin hiçbirinde C. albicans varlığı gösterilemedi. Gruplar arasında farklı Candida türlerinin sayısına göre anlamlı bir fark gözlenmedi (P>0.05). Farklı Candida türlerinin gruplar içerisindeki seviyeleri incelendiğinde; sağlıklı örneklerde C. glabrata (103DNA/50 mg), displazi grubunda C. parapsilosis (104DNA/50 mg), karsinoma in-situ grubunda C. tropicalis-C. kruseii (103DNA/50 mg), SHK grubunda ise C. kruseii’nin (103DNA/50 mg) en fazla sayıda gözlenen Candida türü olduğu belirlendi. Candida türlerinin gruplar içerisindeki dağılımı anlamlı değildi (P>0.05).Sonuç: Sağlıklı, displazik, karsinoma in situ ve skuamöz hücreli karsinoma doku örneklerinde Real-Time PCR yöntemiyle yapılan kantitatif değerlendirmede Candida türlerinin tüm gruplarda benzer oranda mevcut oldukları belirlendi.ANAHTAR KELİMELER Oral Candida, C. albicans, ağız kanseri, Real-Time PCR, moleküler analiz &nbsp

THE EFFECTS OF 3D MODELING ON PLANNING OF MAXILLOFACIAL SURGERY: A Preliminary CBCT STUDY

Abstract: Objectives: The aim is to evaluate the contribution of 3D modeling data to the planning of the maxillofacial surgery and to determine the indications of 3D modeling. Materials and Methods: In this preliminary study, CBCT images of 2 patients with the Kodak 9000 3D (Kodak Carestream Health, Trophy, France) system were used. The segmentation procedures of the pathologies were performed manually, and was followed by the construction of the 3D models. A questionnaire was prepared by consensus of the research team, including the parameters which are critical in preoperative maxillofacial surgery planning. Five oral and maxillofacial surgeons independently evaluated both the traditional CBCT data and 3D model assisted data under the same viewing conditions. The extent of their decision change was scored using a 2 point Likert scale. Conventional (pre 3D model) versus 3D model assisted data (post 3D model) scores were analyzed. Pair-wise comparisons were completed using Fisher’s exact test (P < 0.05). Kappa was used to measure inter-observer agreement. Results: In both of the evaluation sessions (pre and post 3D model), operation time, defect size and complication risk factors showed the highest variation for both patients. The difference between the decision change proportions for the variables of pre and post 3D model sessions were not statistically significant (p>0.05). Except 2 observers with excellent agreement for both evaluations (p=0.036), the agreement rates were fair without statistical significance. Conclusions: The results confirmed that personalized 3D modeling constructed by CBCT data may lead to changes in surgical treatment planning protocol of complex cases

Development, characterization, and in vivo assessment of mucoadhesive nanoparticles containing fluconazole for the local treatment of oral candidiasis

This study aimed to develop a suitable buccal mucoadhesive nanoparticle (NP) formulation containing fluconazole for the local treatment of oral candidiasis. The suitability of the prepared formulations was assessed by means of particle size (PS), polydispersity index, and zeta potential measurements, morphology analysis, mucoadhesion studies, drug entrapment efficiency (EE), in vitro drug release, and stability studies. Based on the optimum NP formulation, ex vivo drug diffusion and in vitro cytotoxicity studies were performed. Besides, evaluation of the antifungal effect of the optimum formulation was evaluated using agar diffusion method, fungicidal activity-related in vitro release study, and time-dependent fungicidal activity. The effect of the optimum NP formulation on the healing of oral candidiasis was investigated in an animal model, which was employed for the first time in this study. The zeta potential, mucoadhesion, and in vitro drug release studies of various NP formulations revealed that chitosan-coated NP formulation containing EUDRAGIT(®) RS 2.5% had superior properties than other formulations. Concerning the stability study of the selected formulation, the formulation was found to be stable for 6 months. During the ex vivo drug diffusion study, no drug was found in receptor phase, and this is an indication of local effect. The in vitro antifungal activity studies showed the in vitro efficacy of the NP against Candida albicans for an extended period. Also, the formulation had no cytotoxic effect at the tested concentration. For the in vivo experiments, infected rabbits were successfully treated with local administration of the optimum NP formulation once a day. This study has shown that the mucoadhesive NP formulation containing fluconazole is a promising candidate with once-a-day application for the local treatment of oral candidiasis

Ağız kanserlerinde virüs izleri

The role of viruses in oral carcinogenesis has been thoroughly investigated in recent two decades; however due to the varieties among the sensitivities of the methods used, the results have differed widely; some researchers have pointed out the effects of viruses in the development of oral cancers, whereas there are many others reporting the adverse and contradictory findings. the major viral agents investigated in oral cancerogenesis are Epstein-Barr viruses, Humanpapillomaviruses (HPV) and Humanherpesviruses [(Herpes Simpleks virus (HSV), Humanherpesvirus-8 (HHV-8), Hiimanherpesvirus-6 (HHV-6)[ from the Herpesviruses. in this review, the aim was to scrutinize the structures, features and potential mechanisms of action of these viruses in tumour development.Son 20 yıldan beri, kanser etiyolojisinde virüslerin etkinliği birçok araştırıcı tarafından değerlendirilmektedir, ancak elde edilen sonuçlar kullanılan yöntemlerin duyarlılığına bağlı olarak farklılık göstermektedir: kimi araştırıcılar viral organizmaların ağız kanserlerinin meydana gelmesinde rolü olabileceğini bildirirken, aksi yöndeki bulguları gösteren ve çelişkili sonuçlar sunan araştırmalar da literatürde yer almaktadır. Ağız kanserlerinin oluşumunda katkıları olduğu düşünülen başlıca virüsler, Herpesvirüs grubu içerisinde yer alan Epstein-Barr, Humanpapillomavirüs (HPV) ve Humanherpesvirüsleri [(Herpes Simpleks virüsü (HSV), Humanherpesvirüs-8 (HHV-8), Humanherpesvirüs-6 (HHV-6)]'dir. Sunulan derleme, yapıları, özellikleri ve tümör gelişimindeki olası etki mekanizmaları açısından bu ajanların irdelenmesini amaçlamaktadır

DENTAL DİJİTAL GÖRÜNTÜLEMEDE ÜÇÜNCÜ BOYUT

Dental volumetric tomography (DVT), which is developed uniquely for dentomaxillofacial imaging, appeared in the dental world concurrently with recent rapid developments in digital radiology technology, and is becoming more popular in dental practice. DVT devices that generate lower radiation doses and have lower cost when compared to medical CT enable acquirement of three dimensional data and reconstruction of these digital images on personal computers. In this review, the principles, technical features, indications, advantages and disadvantages of DVT systems are presented.Son yıllarda hızla ilerleyen dijital radyoloji teknolojisinin ürünü olan ve özellikle dentomaksillofasiyal yapıların görüntülenmesi amacıyla geliştirilen dental volumetrik tomografi (DVT), diş hekimliği uygulamalarında her geçen gün daha fazla kullanım alanı bulmaktadır. Medikal bilgisayarlı tomografi cihazlarına göre daha ucuz ve daha düşük radyasyon dozuna sahip olan DVT cihazları, diş hekimliğinde üç boyutlu verilerin elde edilmesine ve görüntüler üzerinde rekonstrüksiyon işlemlerinin yapılabilmesine olanak sağlamaktadır. Bu derlemede DVT görüntüleme sistemlerinin çalışma prensipleri, teknik özellikleri, kullanım alanları, avantaj ve dezavantajları ile ilgili genel bilgiler sunulmaktadır