Protetik Diş Tedavisi Ana Bilim Dalı Koleksiyonu

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https://hdl.handle.net/20.500.13055/30

Listeleniyor 1 - 19 / 19

Post-processing protocols in 3d printed dental restorations: A literature-based data analysis
(Dennis Barber Journals, 2025) Mert, Selen Elif; Özkan, Yiğit Alp; Olkun, Abdullah Yaşar; Dilaverler Yardım, Esra Ayşe
Objectives: This literature-based data analysis aims to evaluate the effects of post-processing protocols on the physical, mechanical, and surface properties of dental restorations produced using 3D printing technologies (SLA, DLP, and LCD systems). The objective is to highlight the variability in current approaches and thematically analyze the clinical implications of these differences. Materials-methods: A systematic search of the literature published between 2018 and 2025 was conducted using PubMed, Scopus, and Web of Science databases, in accordance with PRISMA guidelines. Inclusion criteria were: (1) studies involving 3D printed resins, (2) evaluation of at least one post-processing variable (e.g., curing, cleaning, or support removal), and (3) focus on definitive or interim prosthodontic restorations. Studies involving orthodontic models, aligners, or CAD/CAM-milled restorations were excluded. The included studies were categorized into three groups: curing protocols, cleaning procedures, and support structure removal. Due to methodological heterogeneity, no meta-analysis was performed; instead, findings were interpreted through a descriptive, literature-based data analysis approach. RESULTS: A total of approximately 320 unique studies were identified through prior systematic and narrative reviews. After applying predefined inclusion criteria, 12 studies were selected for in-depth evaluation in this literature review. Although some included studies were systematic reviews and meta-analyses, this study did not perform an independent meta-analysis. Variations in curing time, light intensity, and atmospheric conditions were found to affect degree of conversion, microhardness, and flexural strength. Cleaning protocols involving different solvents and application techniques influenced surface roughness and dimensional accuracy. The support removal process impacted marginal adaptation, surface integrity, and gloss retention. Despite methodological differences, the overall evidence indicates that post-processing parameters significantly influence clinical performance outcomes. Conclusion: This analysis demonstrates that post processing protocols significantly affect material quality and clinical applicability. The findings underscore the need for manufacturer-independent, standardized protocols to ensure predictable outcomes in 3D printed dental restorations.
Prosthetic rehabilitation of a large maxillary defect due to nasopharyngeal tumor resection: A case report
(Dennis Barber Journals, 2025) Topuz, Buğra Tuğ; Kasıl, Ece; Ayvalıoğlu Şamiloğlu, Demet Çağıl
Introduction: Nasopharyngeal tumors are malignant neoplasms located in the epithelial lining of the nasopharynx, and they often require aggressive treatment modalities including surgery, radiotherapy, and/or chemotherapy. Surgical resection of these tumors, especially when involving adjacent maxillary and palatal structures, frequently results in large maxillofacial defects. This case report presents the comprehensive prosthetic rehabilitation of a patient with a large acquired maxillary defect following surgical resection of a nasopharyngeal tumor. Case Description: A 49 years old male patient with a large maxillary defect resulting from extensive surgical nasopharyngeal tumor resection applied to the clinic of Department of Prosthodontics. Following surgery, the patient had received postoperative radiotherapy and chemotheraphy. Prior to definitive prosthetic rehabilitation, endodontic and periodontal treatments of the remaining teeth were completed. Support was taken from the remaining teeth (16-15, 12-11-21- 22) to fabricate a precision attachment-retained obturator that provided partial separation between the oral and nasal cavities. A quadrilateral design was performed. For the mandibular partial edentulism, a precision attachment-retained, metal framework removable partial denture was designed. Results: The patient’s issues with speech and nutrition deficiency were resolved with the obturator prosthesis and the esthetic demands were fullfilled. Conclusion: Within the scope of this case, the use of an obturator provided functional and esthetic rehabilitation of a patient with a large maxillary defect following oncologic surgery.
Prosthetic approach to tooth structure damage associated with dietary habits and bruxism: A case report
(Dennis Barber Journals, 2025) Özkan Dayıoğlu, Selin; Ayvalıoğlu Şamiloğlu, Demet Çağıl; Rastgar Safari, Mahya
Introduction: Tooth structure loss resulting from parafunctional habits such as bruxism, compounded by erosive dietary factors, presents a multifactorial challenge in restorative dentistry. Patients often exhibit a combination of advanced anterior wear, dentin hypersensitivity, and non carious cervical lesions. Successful rehabilitation requires a minimally invasive, esthetically driven, and functionally stable prosthetic approach. This case presents a comprehensive adhesive and occlusal strategy for managing tooth wear caused by bothbruxism and dietary habits. Case Description: A 54-year-old female patient presented with severe anterior tooth wear, dentin hypersensitivity, and non carious cervical lesions attributed to parafunctional habits, particularly bruxism. The maxillary central incisors exhibited significant structural compromise and esthetic concerns. To fulfill the functional and esthetic needs of the patient, lithium disilicate crowns were placed on the maxillary central incisors. Additionally, seven maxillary anterior teeth were restored using minimally invasive lithium disilicate laminate veneers. A monolithic zirconia crown was placed on the maxillary first molar to reinforce posterior occlusal support. Tooth preparations followed adhesive principles, and the occlusion was carefully evaluated and adjusted. A protective occlusal splint was delivered post-treatment to eliminate future damage. Discussion: This case emphasizes the importance of early diagnosis and a comprehensive, adhesive-based prosthodontic treatment plan in managing bruxism induced tooth wear. Lithium disilicate ceramics allowed for both conservative tooth preparation and high esthetic outcomes. The use of a monolithic zirconia crown in the posterior ensured durability. The integration of occlusal assessment and an occlusal splint served as critical components for maintaining long-term stability. Conclusion: Through a customized, adhesive prosthodontic strategy, it was possible to restore esthetics, relieve sensitivity, and prevent further damage in a patient affected by bruxism.
Photogrammetry-assisted digital workflow for full-arch monolithic zirconia restorations: A clinical report
(Dennis Barber Journals, 2025) Güler, Edanur; Sabancı, Nibal; Dilaverler Yardım, Esra Ayşe
Introduction: Achieving cross-arch accuracy and passive fit remains a major challenge in conventional impression techniques for full-arch implant restorations. In contrast, photogrammetry-assisted digital workflows offer enhanced precision, efficiency, and predictability. This clinical report describes the rehabilitation of a 56-year-old fully edentulous female patient using a fully digital protocol and monolithic zirconia prostheses for both jaws. Case Description: Twelve endosseous implants (Ø3.7 mm, length 10–12 mm; ETK, France) were placed in anterior and posterior regions of the maxilla and mandible. After successful osseointegration, multi-unit abutments were connected. Final impressions were obtained using a hybrid protocol that combined photogrammetry (Imetric-Icam, Switzerland) with intraoral scanning (iTero Lumina, USA). With reference bars in place, interocclusal records and vertical dimension were registered using C-type vinyl siloxane ether (Zetaplus, Zhermack, Italy). Facial photographs and marker data were recorded in natural head position and transferred to the laboratory. Digital alignment and virtual articulation (Artex, Germany) were performed. A CAD-CAM resin mock-up (Armaresin, Turkey) was fabricated and evaluated intraorally for esthetics and occlusion. Final restorations were designed as full-arch, screw-retained prostheses using monolithic zirconia (Ceramill Zolid FX, Amann Girrbach, Austria) and torqued to 15 Ncm. Discussion: The photogrammetry-based workflow demonstrated superior cross-arch accuracy and passive fit compared to conventional techniques. The try-in allowed for verification of occlusal harmony, vertical dimension, and esthetics in a single appointment. Follow-up at 1-, 3-, 6-month, and 1-year intervals revealed no peri-implant complications. The patient reported high satisfaction in function and esthetics. This case highlights the clinical advantages of photogrammetry and monolithic zirconia in streamlining full-arch implant rehabilitation.
Mandibular overdenture supported by two canines: A two-year clinical follow-up case report
(Dennis Barber Journals, 2025) Eyidemir, Bahar; Güler, Edanur; Papatya, Zeynep; Dilaverler Yardım, Esra Ayşe
Introduction: Mandibular complete dentures often present insufficient retention and stability due to anatomical limitations in edentulous patients. Although implant therapy is commonly used to address these issues, it may not be feasible in patients with systemic conditions that contraindicate surgical interventions. In such cases, preserving and utilizing remaining natural teeth as abutments can enhance prosthetic success while minimizing invasiveness and improving patient comfort. Tooth-supported overdentures are a valuable alternative, particularly when strategic teeth such as canines are available. Case Description: A 60-year-old male patient with a history of diabetes mellitus presented with complaints of instability in his mandibular complete denture. The patient exhibited a fully edentulous maxilla and retained only two mandibular canines. Implant therapy was contraindicated due to his systemic condition. As an alternative, a tooth supported mandibular overdenture was planned. Clinical and radiographic evaluations confirmed that both canines were periodontally and structurally suitable for overdenture support. Endodontic treatment was performed, and the clinical crowns were reduced to allow sufficient space for prosthetic components. Cast copings with ball attachments were fabricated and cemented. A mandibular overdenture incorporating matching female housings was constructed and delivered. A conventional complete denture was also fabricated for the maxilla. The patient was recalled every six months for clinical evaluation and maintenance. Over a two-year follow-up period, no complications such as attachment loosening, mucosal irritation, or abutment failure were observed. The patient reported high satisfaction in terms of masticatory function, prosthesis stability. Discussion: This case demonstrates that, in patients for whom implant therapy is contraindicated, mandibular overdentures supported by two natural canines with ball attachments can offer a stable, functional, and long-term treatment solution. Tooth-supported overdentures provide biomechanical advantages and improve patient satisfaction through a minimally invasive approach. The strategic use of retained natural teeth, particularly canines, remains a clinically effective alternative for managing mandibular edentulism.
Functional and esthetic outcomes of full-mouth rehabilitation following vertical dimension reestablishment using posterior composite build-ups: A case report
(Dennis Barber Journals, 2025) Papatya, Zeynep; Güler, Edanur; Karabulut, Dicle; Özdal, Umut
Introduction: Loss of vertical dimension of occlusion (VDO) is a clinical condition that can significantly impact both function and esthetics. It may lead to impaired mastication, temporomandibular joint (TMJ) discomfort, facial disharmony, and reduced quality of life. Restoring VDO requires a systematic approach involving proper evaluation, neuromuscular adaptation, and establishment of a stable occlusal and TMJ relationship. This case report presents the functional and esthetic outcomes of full-mouth rehabilitation following VDO reestablishment using posterior composite build-ups and a gradual increase in occlusal height to promote TMJ stabilization. Case Description: A patient with reduced VDO was treated with posterior composite resin build-ups. The vertical dimension was increased by 1 mm per week over five weeks, allowing neuromuscular adaptation and TMJ repositioning. After successful adaptation, definitive restorations were completed. Pressable ceramic (e.max) laminate veneers were placed from first premolar to first premolar (5–5) in both arches. Zirconia crowns were used on the first and second molars (6 and 7). Throughout the procedure, esthetic, functional, and occlusal parameters were carefully monitored to ensure optimal outcomes. The patient adapted well to the new VDO, showing marked improvement in facial esthetics and occlusal function. High patient satisfaction was reported at the conclusion of treatment. Discussion: This case highlights the effectiveness of a controlled, stepwise approach to VDO restoration. Using composite build-ups allowed reversible testing of neuromuscular tolerance before final restorations. The combination of e.max veneers and zirconia crowns restored function and esthetics while preserving TMJ stability. No complications were observed during the one-month follow up, supporting the short-term success of the approach. Long term monitoring is essential to confirm the durability of results.
Endocrown-based restoration of a structurally compromised tooth using additive manufacturing in a fully digital workflow: A case report
(Dennis Barber Journals, 2025) Keskin, Muhammed Furkan; Altaş, Zeynep Tuğçe; Dilaverler Yardım, Esra Ayşe
Introduction: The rapid advancement of digital technologies in dentistry has facilitated the effective integration of CAD/CAM systems into restorative treatment protocols. These systems enable both subtractive and additive manufacturing methods to be incorporated into clinical workflows. Endocrowns, preferred for restoring endodontically treated teeth with compromised structural integrity, offer significant advantages in terms of precision and time efficiency when digitally planned and fabricated. Case Description: A 33-year-old male patient presented to the clinic with complaints of acute dental pain. Clinical and radiographic evaluations revealed deep dentinal caries and extensive coronal substance loss in the affected tooth, for which endodontic treatment was indicated. Following root canal therapy, an endocrown restoration was selected to preserve the remaining tooth structure and restore functional integrity. The treatment was carried out entirely using a digital workflow. An intraoral scanner (TRIOS® 3 Color, 3Shape, Denmark) was used to capture the digital impression. The restoration was designed using CAD software (Exocad, Germany) and subsequently fabricated using additive manufacturing technology with a 3D printer (Asiga MAX, Australia) and high-precision dental resin. The restoration was cemented using adhesive techniques in a clinical setting. Discussion: Endocrowns fabricated through a fully digital workflow demonstrate superior accuracy, workflow standardization, and time efficiency compared to conventional methods. Additive manufacturing enables the precise production of complex morphologies, eliminates the need for physical models, reduces material waste, and enhances cost-effectiveness. These restorations exhibit high clinical compatibility and improve patient comfort while reducing operator dependency during production. However, limitations such as high system acquisition costs, the need for technical proficiency, and limited long-term clinical data must be considered for widespread adoption.
Scientific accuracy of large language models in tilted implant dentistry: A guideline-based comparative evaluation
(Wolters Kluwer, 2026) Yıldız, Mehmet S.; Alkap, Melek; Özdal, Umut; Özdal Zincir, Özge
Tilted dental implant systems are widely used in the rehabilitation of anatomically compromised jaws and are supported by international consensus guidelines. Concurrently, large language models (LLMs) are increasingly accessed as informational tools in implant dentistry; however, their scien tific accuracy and adherence to guideline-based principles in advanced implant concepts remain insufficiently explored. This study evaluated the scientific accuracy, guideline conformity, and clinical consistency of responses generated by 4 LLMs regarding tilted dental implant systems. A total of 120 guide line-based questions covering 8 predefined domains (definition, indications, contraindications, advantages, surgical procedure content, prosthetic procedure content, complications, and prognosis/survival) were developed in accordance with ITI, EAO, and AAOMS consensus reports. Each question was in dependently submitted to ChatGPT-5.2, Copilot, DeepSeek, and Gemini, and all responses were anonymized and evaluated by a multidisciplinary expert panel using a structured ordinal scoring system. Overall, scientific accuracy scores were high across all models, with near-ceiling performance observed in domains related to indications, advantages, procedural con tent, and prognosis. Statistically significant between-model differences were identified in the definition (P = 0.003), con traindications (P = 0.006), and complications (P < 0.001) do mains, with DeepSeek and Gemini demonstrating consistently higher scores in complication-related content compared with ChatGPT and Copilot. Within-model analyses further revealed significant domain-dependent variability across all LLMs. Al-though LLMs demonstrate a strong capacity to reproduce es tablished, guideline-based knowledge regarding tilted implant systems, limitations remain in safety-critical domains requiring nuanced clinical judgment. Accordingly, LLMs should be re garded as adjunctive educational tools rather than substitutes for expert decision-making in craniofacial implantology.
Are informations of subperiosteal implant procedure on youtube really useful?
(Udruženje stomatologa Balkana, 2025) Özdal Zincir, Özge; Zincir, Ali; Özdal, Umut
Background/Aim: Subperiosteal implant is a type of implant preferred in oral implantology in cases with severe bone deficiency where intraosseous implant application cannot be performed. We evaluated the accuracy of the information by examining YouTube videos containing information on this subject. Material and Methods: In the YouTube video search conducted with the keywords ‘Subperiosteal dental implant’, the first 200 videos were watched and evaluated. 118 videos that didn’t meet the analysis criteria were excluded from evaluation and the remaining 82 videos were analyzed. The usefulness scores of all analyzed videos were determined as ‘poor’, ‘moderate’ and ‘excellent’ according to their information content. For statistical analysis, the Kruskal Wallis and Phi tests were used and the significance coefficient was determined as p<0.05. Results: According to the information content of the videos, the usefulness scores were numbered as poor(0), moderate(1), excellent(2) and the average was found to be 0.51. When the usefulness scores of the videos and their demographic information were compared, it was found that there was a significant difference between the video duration (p=0.002), the number of views (p=0.006) and the number of likes (p=0.003). There is a significant difference between the viewing rate of the videos (p=0.044) according to their usefulness scores. It can be stated that video types differ depending on the target audience (p=0.003). Conclusions: Among the YouTube videos examined, those uploaded by health professionals and health companies have a high educational quality and a high viewing rate. However, the number of such videos aimed at informing patients should be increased.Key words: Dental implant, subperiosteal implant, dental prosthesis, social media.
Protetik diş hekimliğinde fotopolimer dental reçineler
(Gece Kitaplığı, 2025) Dilaverler Yardım, Esra Ayşe; Mert, Selen Elif
Protetik diş hekimliğinde kullanılan üretim yöntemleri, son yıllarda dijital teknolojilerin gelişimine paralel olarak önemli bir dönüşüm süre cinden geçmektedir. Geleneksel döküm, presleme ve frezeleme temelli üretim yöntemlerinin yerini, bilgisayar destekli tasarım ve üretim sistem leri (Computer-Aided Design/Computer-Aided Manufacturing – CAD/ CAM) ile birlikte eklemeli üretim teknolojileri (Additive Manufacturing – AM) almaya başlamıştır. Bu teknolojiler, üretim doğruluğunu ve işlem hızını artırarak materyal kullanımında verimlilik sağlamış, aynı zaman da kişiye özgü protetik restorasyonların üretilmesini mümkün kılmıştır.
Video-assisted learning on youtube in dentistry education: The impact of overdenture videos on dentistry students
(Dennis Barber Journals, 2025) Olkun, Abdullah Yaşar; Özkan, Yiğit Alp; Dilaverler Yardım, Esra Ayşe
OBJECTIVES: This study aimed to evaluate the effectiveness of video-assisted learning on the knowledge and perceptions of dental students regarding implant-supported overdentures, which represent a challenging but essential aspect of prosthodontic treatment. The increasing use of digital platforms for educational purposes motivated this research. MATERIALS-METHODS: A prospective pretest–posttest intervention study was conducted involving 4th- and 5th-year dental students at Istanbul Health and Technology University. Participants initially completed a 15-item multiple-choice test designed to assess their baseline theoretical knowledge of implant supported overdenture procedures. Students watched the selected educational video demonstrating key clinical steps, including implant positioning, abutment selection, impression-taking techniques, and prosthesis fitting. After the video session, students completed the same knowledge test to evaluate knowledge gain, as well as a 10-item Likert-scale survey to assess their perceptions about the video’s clarity, educational value, engagement, and motivational impact. Data were statistically analyzed using paired t-tests for knowledge score comparisons and descriptive statistics for survey results.Students complete the survey via Google Forms. RESULTS: Analysis revealed a statistically significant increase in post-intervention test scores, indicating an improvement in students’ understanding of overdenture concepts and clinical procedures. Survey responses reflected positive student attitudes toward video-assisted learning, highlighting increased clarity, engagement, and confidence in managing implant-supported overdentures. Most students expressed a preference for integrating similar video modules into their formal prosthodontic education. CONCLUSION: Video-assisted learning through widely accessible platforms such as YouTube serves as an effective supplementary educational tool in dental training. It enhances both theoretical knowledge and practical confidence in complex prosthodontic procedures like implant-supported overdentures. Incorporating such multimedia resources into dental curricula is strongly recommended to enrich student learning experiences and outcomes.
In vitro evaluation of methyl methacrylate (MMA) release from different temporary denture base materials
(Dennis Barber Journals, 2025) Dilaverler Yardım, Esra Ayşe; Özer, Safa; Atasoyu Akgün, Begüm; Çakan, Umut
INTRODUCTION: Residual methyl methacrylate (MMA) released from temporary denture base materials is of clinical concern due to its potential biological effects. Recently, light polymerized and 3D-printed denture base resins have emerged as alternatives to conventional cold-polymerized acrylics. This study aimed to compare the in vitro MMA release levels of three clinically relevant temporary denture base materials. MATERIALS AND METHODS: Three materials were tested: cold-polymerized acrylic resin, light-polymerized baseplate resin, and 3D-printed denture base resin. Ten samples were prepared for each group (n=10), standardized to 0.05 g per specimen. Samples were immersed in 2 mL and 5 mL of artificial saliva and incubated at 37°C. MMA release was quantified using high-performance liquid chromatography (HPLC) at 15 minutes, 30 minutes, 1 hour, and 24 hours. Data distribution was analyzed with the Shapiro-Wilk test; the effects of time, material, and saliva volume were assessed using two-way ANOVA and Tukey post-hoc tests (p<0.05). RESULTS: No MMA release was detected before 24 hours in the 3D-printed and light-polymerized groups. The cold polymerized acrylic group showed progressive MMA release starting from 15 minutes, with a significant increase over time (p<0.001). At 24 hours, it exhibited the highest MMA levels among all groups. A significant difference between 2 mL and 5 mL saliva volumes was observed only in the cold-cure group. The 3D-printed resin showed the most stable performance across all time points. CONCLUSION: Temporary denture base materials should be selected with consideration of residual monomer release. The results support the biocompatibility of 3D-printed resins for short-term clinical applications, especially when early MMA release and toxicity are of concern.
The effect of commonly used polishing protocols on the color stability of 3D- printed temporary crowns
(Dennis Barber Journals, 2025) Yazar Özdemir, Nedime Zeynep; Dilaverler Yardım, Esra Ayşe
OBJECTIVE: Color stability is a crucial parameter for maintaining the long-term esthetic success of temporary restorations. This study aimed to evaluate the effects of different clinical polishing protocols applied to three-dimensional (3D) printed temporary resin crowns on their color stability. MATERIALS-METHODS: Fifty standardized specimens (12×12×2 mm) were prepared using a 3D printing resin material (PowerResins, Temp Resin, A2, Turkiye) and randomly divided into five groups (n=10) as G1: Control (no polishing), G2: Mechanical polishing (DCPT 14 RA SET), G3: Silicon dioxide containing polishing paste (Promida Prophy P), G4: Mechanical + silicon dioxide paste, G5: Diamond particle-containing polishing paste (Intensiv Unigloss). Initial color measurements were performed using a digital spectrophotometer (Vita Easyshade V). TSpecimens were exposed to a daily coffee cycle for 15 days. Color differences were calculated using the CIEDE2000 (ΔE00) formula, and the data were analyzed by one way analysis of variance (ANOVA). Tukey’s post-hoc test was applied for multiple comparisons (p < 0.05). RESULTS: No significant differences were observed between the groups before the coffee staining cycle (p > 0.05). After staining, intergroup differences were statistically significant (p < 0.05). The lowest ΔE00 values were recorded in G5 (diamond particle- containing polish). G3 and G4 exhibited moderate color changes, comparable to the control group (G1). The highest color change was observed in G2 (mechanical polishing only), with ΔE00 values exceeding the clinically perceptible threshold (ΔE00 ≥ 0.8). CONCLUSION: The diamond particle-containing polishing paste provided the best color stability both statistically and clinically. The polishing protocol plays a decisive role in the color stability of 3D-printed temporary crowns. The use of diamond-containing polishing systems is recommended, particularly in esthetic zone restorations.
Dental shade assessment via various digital photograph parameters: A pilot study
(EPA - TPID, 2025) Yılmaz, Seval Fatma; Ayvalıoğlu Şamiloğlu, Demet Çağıl
OBJECTIVES: Accurate shade matching is essential for successful restorative and prosthodontic dental treatments. Various methods, including visual, digital, and spectrophotometric techniques, have been utilized for shade selection. However, there is limited data regarding the optimal photographic parameters that yield the most accurate shade matching in digital photography. This pilot study aims to evaluate color differences arising from variations in photographic parameters -specifically camera aperture and ISO-while maintaining a constant shutter speed of 1/125. MATERIALS-METHODS: Spectrophotometric shade analysis (VITA Easyshade) was performed ten times on the maxillary right central incisor of a subject and the A1 tab from the VITA Classical shade guide before photography. A total of 12 digital images were captured using a DSLR camera (Canon EOS 850D) equipped with a 100 mm macro lens and ring flash (without polarized filter). The photographic parameters included a constant shutter speed (1/125 s), varying aperture values (f/11, f/13,f/22, f/32), and ISO values (100,160,200). Colorimetric evaluations were conducted using Adobe Photoshop, analyzing CIE Lab* coordinates and calculating ΔE values. RESULTS: The lowest ∆E value was recorded with ISO 200, f/32 aperture, and 1/125 shutter speed in the tooth group (5.41 ± 1.92), while the highest ∆E value was obtained with ISO 100, f/11 aperture, and 1/250 shutter speed in the shade guide group (62.14 ± 3.90). The digital photographic ∆E values mostly remained within the clinically unacceptable threshold (ΔE > 2.7 and ≤ 5.4). CONCLUSION: Within the limitations of this pilot study, digital photography alone for shade selection remains inconclusive.Further studies are warranted to comprehensively compare shade-matching accuracy using digital photography.
Farklı dental tarayıcı teknolojilerinin doğruluklarının değerlendirilmesi: In-Vitro çalışma
(7tepe Klinik, 2024) Ayvalıoğlu Şamiloğlu, Demet Çağıl; Beydili, Serra Nur
GİRİŞ ve AMAÇ: Diş hekimliğinde dijital teknolojinin kullanımı CAD/ CAM sistemlerinin hayatımıza girmesiyle son yıllarda oldukça artmıştır. CAD/CAM sistemleri ile bir iş akışı ağız içi tarayıcılarla direkt veya masaüstü tarayıcılarla indirekt yöntem ile başlayarak takip edilebilir. Bu çalışmanın amacı, tam ark dişli çenelerde masaüstü tarayıcı ve ağız içi tarayıcıların doğruluklarının değerlendirilmesidir. YÖNTEM ve GEREÇLER: Tam ark dişli çene modelinde yer alan kanin ve molar dişleri üzerinde, ISO standartları çerçevesinde, dört adet 6 mm çapında negatif küre oluşturulmuştur. Standart ışıksız ortamda, model, Dijital Şerit Projeksiyon Teknolojisi, Aktif Triangulasyon ve Konfokal Mikroskopi teknolojilerine sahip tarayıcılar ile firmanın önerdiği tarama protokolleriyle 20 kez taranarak dijitalize edilmiştir. Kontrol grubu, referans dijital data, endüstriyel tarayıcı (Solutionix C500, MEDIT) ile elde edilmiştir. Elde edilen tüm dijital data, 3 boyutlu (3B) analiz yazılım programı ile değerlendirilmiştir (Geomagic studio 2015; 3D Systems Inc., Almanya). Normal dağılan veriler için tek yönlü ANOVA ve post hoc Bonferroni testi, normal dağılmayan veriler için Bonferroni, Kruskal-Wallis testi ile değerlendirilmiştir (α=0,05). BULGULAR: Tam ark dişli model taramalarının doğruluğu, masaüstü tarayıcı ve ağız içi tarayıcıların tipine bağlı olarak anlamlı farklılık göstermiştir (p˂0,05). Her iki ağız içi tarayıcı arasında tarama doğruluğu bakımından istatistiksel olarak anlamlı fark bulunmuştur (p˂0,05). TARTIŞMA ve SONUÇ: Tam ark taramalarda dijital sistemlerin kullanılması klinik olarak kabul edilebilir sonuçlar göstermektedir.
Effect of scanbody material and mucosa modification technique on the accuracy of digital impressions of edentulous arches with multiple implants
(Necmettin Erbakan University, 2024) Göksoy, Görkem; Ayvalıoğlu Şamiloğlu, Demet Çağıl; Gökçen-Röhlig, Bilge
Aim: The aim of current research is to evaluate the effect of scanbody material and additional reference markers in the form of artificial landmarks on the accuracy of digital impressions of edentulous arches with multiple implants. Material and Methods: A model of an edentulous maxilla with six implants (BLT, RC, Institut Straumann, AG) was used as master model. PEEK and PMMA scanbodies were screwed on the implants and digital impressions were obtained with an intraoral scanner (TRIOS4, 3Shape). Reference markers made of flowable composite (C), gingival barrier material (GB), scannable silicone (S) were placed on the edentulous spaces and impressions were obtained. The master model was digitalized with an extraoral highresolution reference scanner. Deviations of the predetermined points and inter-implant distances were calculated by using superimpositining technique. Results: Inter-implant distance measurements showed that PEEK scanbodies demonstrated better precision than PMMA scanbodies, (p<.001). In the subgroups, also PEEK groups were more accurate than PMMA groups (p<.001). Kruskal-Wallis test also showed statistical difference in deviations of the predetermined points among the groups in precision (p<.001). Addition of markers did not influence the precision and trueness in PEEK groups but in PMMA groups both in distance measurements and predetermined point deviations. Conclusion: Addition of reference markers does not make any significance in the accuracy of digital impressions when PEEK scanbodies are used. PMMA seems not to be an alternative material as scanbody material, addition of markers is needed.
Evaluation of stress distributions in all ceramic conometric single crown restorations: 3-dimensional finite element analysis
(Marmara Üniversitesi, 2024) Vural, Sinem; Evren, Buket; Yıldız, Coşkun
Objective: The aim of the study is to compare the effect of monolithic translucent zirconia ceramic (TZI) and monolithic lithium disilicate glass ceramic (LDS) restorative materials on stress distributions in implant components and surrounding bone tissues in implant-supported conometric single crown restorations with a conical connection system by using 3D finite element analysis. Methods: Restorations produced with two different all-ceramic materials using a conometric abutment and a conometric cap on the implant with a conical connection system were placed in the maxillary right second premolar region. 3D finite element analysis was used to examine the amount and distribution of stresses in implant components, in cortical and cancellous bone tissues surrounding the implant and in crowns under vertical and oblique loading. For the statistical analysis one-way ANOVA and independent samples t-test were used (p<.05). Results: In oblique 100N simulation, maximum stress distribution in implant and its components occurred at the implant abutment contact as 475.63 MPa for the LDS. The screw’s peak stress values were determined to be 239.09 MPa in the transition zone and 280.061 MPa in the thread. On the bone surface, maximum and minimum cortical principal stress values were 61.25 MPa and – 62.028 MPa. During oblique loading, LDS exhibited the greatest surface stress on the cap as 441.33 MPa. Generally, tapping phase showed the lowest stress (p<.05). There was no significant difference regarding the materials (p> .05). Conclusion: von Misess and principal stresses are not very high in any location therefore conical connections are more promising in terms of future success.
Comparison of fiber reinforcing methods of composite resin: Aflexural strength and stereo microscopy study
(Wiley, 2023) Cengiz, Seda; Bağış, Bora; Külünk, Şafak; Velioğlu, Neslin; Sağlam, Gaye
This study aimed to compare the effect of fiber reinforcing methods on the flexural strength and failure modes of indirect composite resins. Based on the reinforcement methods, the bar specimens (3 x 3 x 25 mm) were divided into five groups (n = 20). Glass or polyethylene fibers were used for reinforcement of indirect composite resins. Fibers were either light polymerized and mixed with indirect composite resin or mixed with indirect composite resin after resin application and polymerized together. Indirect composite resin without fiber reinforcement was used as control. All five types of specimens were stored in distilled water at 37 & DEG;C for 24 h. Half of the specimens were additionally thermocycled. Then the specimens were tested in a three-point bending test. Failure types were examined and categorized by using stereo microscope. The data were analyzed using two-way ANOVA and Tukey HSD test. Flexural strength was found to be significantly higher for fiber-reinforced indirect resin composites than control. However, the fiber-reinforced groups did not present any significant difference. Analysis revealed aging does not affect the flexure strength of fiber reinforcement of indirect composite resin. The study concluded that the flexure strength of indirect composite resins was improved with fiber reinforcement. Different fiber reinforcement methods demonstrated similar effects on the flexure strength of indirect composite resin. Reinforcement with glass or polyethylene fibers presented the potential to improve the mechanical properties of indirect composite resins. Research Highlights Flexural strength of indirect composite resins are affected by the reinforcement of composites with glass or polyethylene fibers. Aging with thermocycling has no effect on the flexural strength of the indirect composite resins, however can cause catastrophic failures in material.
Evaluation of the effect of anodization-colored titanium abutments and zirconia substructure thickness on zirconia substructure color: An In vitro study
(Wolters Kluwer Health, 2022) Baş, B. B.; Çakan, Umut
Background and aim: The aim of this study is to evaluate the effect of anodized titanium abutments and zirconia substructure thickness on the color of zirconia substructure. Materials and methods: In this study, an electrochemical anodization setup was prepared for titanium coloring. Commercial titanium, anodization-colored yellow and pink titanium, and zirconia were used as different abutment specimens. Thirty zirconia discs in 0.7, 0.9, and 1.1 mm thickness were prepared from zirconia blocks as zirconia substructure specimens (n = 10). Zirconia substructure specimens of different thicknesses were placed on abutment specimens of different colors and L*, a*, b* values were measured with a spectrophotometer device. Color difference (ΔE) was calculated according to the CIELab formula by comparing the L*, a*, and b* values obtained on the zirconia abutment with the L*, a*, and b* values obtained on the other abutments. Statistical analyzes were performed with two-way analysis of variance and Tukey Honestly Significant Difference (HSD)test (p < 0.05). Results: The increase in the thickness of the substructure resulted in a statistically significant difference on ΔE, L*, a*, and b* values (p < 0.001). The effect of abutment color had no significant effect on ΔE values. The highest ΔE value was 18.10 at zirconia substructure with 0.7 mm thickness when paired with pink-anodized titanium abutment specimens. Conclusion: The thickness of zirconia substructure and the color of titanium abutments affect zirconia substructure color.

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