Mehmet Selim Bilgin

Fabricating Complete Dentures with CAD/CAM and RP Technologies.

Two techological approaches for fabricating dentures; computer-aided design and computer-aided manufacturing (CAD/CAM) and rapid prototyping (RP), are combined with the conventional techniques of impression and jaw relation recording to determine their feasibility and applicability. Maxillary and mandibular edentulous jaw models were produced using silicone molds. After obtaining a gypsum working model, acrylic bases were crafted, and occlusal rims for each model were fabricated with previously determined standard vertical and centric relationships. The maxillary and mandibular relationships were recorded with guides. The occlusal rims were then scanned with a digital scanner. The alignment of the maxillary and mandibular teeth was verified. The teeth in each arch were fabricated in one piece, or set, either by CAM or RP. Conventional waxing and flasking was then performed for both methods. These techniques obviate a practitioners need for technicians during design and provide the patient with an opportunity to participate in esthetic design with the dentist. In addition, CAD/CAM and RP reduce chair time; however, the materials and techniques need further improvements. Both CAD/CAM and RP techniques seem promising for reducing chair time and allowing the patient to participate in esthetics design. Furthermore, the one-set aligned artificial tooth design may increase the acrylics durability.

A review of computer-aided design/computer-aided manufacture techniques for removable denture fabrication

The aim of this review was to investigate usage of computer-aided design/computer-aided manufacture (CAD/CAM) such as milling and rapid prototyping (RP) technologies for removable denture fabrication. An electronic search was conducted in the PubMed/MEDLINE, ScienceDirect, Google Scholar, and Web of Science databases. Databases were searched from 1987 to 2014. The search was performed using a variety of keywords including CAD/CAM, complete/partial dentures, RP, rapid manufacturing, digitally designed, milled, computerized, and machined. The identified developments (in chronological order), techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication are summarized. Using a variety of keywords and aiming to find the topic, 78 publications were initially searched. For the main topic, the abstract of these 78 articles were scanned, and 52 publications were selected for reading in detail. Full-text of these articles was gained and searched in detail. Totally, 40 articles that discussed the techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication and the articles were incorporated in this review. Totally, 16 of the papers summarized in the table. Following review of all relevant publications, it can be concluded that current innovations and technological developments of CAD/CAM and RP allow the digitally planning and manufacturing of removable dentures from start to finish. As a result according to the literature review CAD/CAM techniques and supportive maxillomandibular relationship transfer devices are growing fast. In the close future, fabricating removable dentures will become medical informatics instead of needing a technical staff and procedures. However the methods have several limitations for now.

Comparison of fracture resistance between cast, CAD/CAM milling, and direct metal laser sintering metal post systems

PURPOSE The purpose of this study was to compare the fracture resistance of Co-Cr post-cores fabricated with 3 different techniques: traditional casting (TC), computer-aided design and manufacturing (CAD/CAM) milling (CCM) and direct metal laser sintering (DMLS). METHODS Forty intact human mandibular premolar were endodontically treated. The roots were then randomly divided into four groups according to the post systems: the control group was only filled with gutta percha. Co-Cr metal posts were fabricated with TC, CCM and DMLS in the other three groups. The posts were luted with a resin cement and subjected to compression test at a crosshead speed of 1mm/min. The statistical analysis of the data was performed using one-way analysis of variance (ANOVA) and multiple comparison post hoc Tukey tests (α=.05). The samples were examined under a stereomicroscope with ×20 magnification for the evaluation of the fracture types. RESULTS The mean fracture loads were 432.69 N for control, 608.89 N for TC, 689.40 N for DMLS and 959.26 N for CCM. One-way ANOVA revealed significant difference between the groups (p<0.01). In the post hoc Tukey test, there were significant differences between groups except DMLS and TC. CONCLUSION While Co-Cr posts fabricated by TC and DMLS systems performed similarly in terms of fracture resistance, posts fabricated by CCM techniques showed higher fracture resistance values. SIGNIFICANCE Co-Cr metal posts fabricated by CCM and DMLS could be an alternative to TC processing in daily clinical application.

Posttreatment diagnosis of caries under fixed restorations: a pilot study.

STATEMENT OF PROBLEM Conventional radiographic techniques are insufficient for detecting caries under fixed restorations or for acquiring clear images of the disease. Advanced radiographic techniques such as cone beam computerized tomography may be a solution. PURPOSE The purpose of this study was to assess the viability of detecting and characterizing caries under complete-ceramic and metal-supported crowns by using cone beam computerized tomography. MATERIAL AND METHODS A grade 6 carious molar tooth according to the International Caries Detection and Assessment System criteria was selected. The tooth was prepared, and 3 different crowns were fabricated in a dental laboratory: yttria tetragonal zirconia polycrystal (Y-TZP) ceramic, lithium disilicate ceramic, and metal ceramic. The crowns were placed on the prepared tooth, and each specimen was subjected to cone beam computerized tomography. Opacity values were recorded and evaluated with 2-way ANOVA. Multivariate comparisons (Tukey was performed to assess the mean gray value differences of the materials between caries and dentin, and the Mann-Whitney U test was performed to assess the mean gray value differences between caries and dentin for each material (α=.05). RESULTS Carious borders and cavities were detected under the 3 ceramic crown specimens with a cone beam computerized tomography radiographic technique. The statistical analysis of the radiopacity mean gray value was at the borderline of significance for the specimen radiographies. Significant differences were found with respect to materials, location, and the interaction between these 2 factors (P<.001). CONCLUSIONS Cone beam computerized tomography can be used as a posttreatment diagnostic technique for detecting caries under high atomic numbered crowns and partial fixed dental prostheses.

CAD/CAM Endocrown Fabrication from a Polymer-Infiltrated Ceramic Network Block for Primary Molar: A Case Report

OBJECTIVE The aim of this case report is to describe the treatment of a primary molar with a deep carious lesion by pulpotomy and placement of a ceramic endocrown. CLINICAL CASE A 7-year-old male patient with profound caries in tooth number 85 was referred to our clinic and underwent a pulpotomy. As the final treatment in tooth restoration, placement of an endocrown was planned, because little more than half of the tooth structure remained. After an additional request from the patients parents for an advanced and prompt restoration, a computer-aided design/computer-aided manufacturing (CAD/CAM) polymer-infiltrated ceramic network (PICN) block was chosen. A three-dimensional model of the arch was obtained after scanning the dental cast, and the endocrown was designed digitally according to the model. When the design was complete, the endocrown was fabricated with a milling machine. Finally, the endocrown was cemented with self-adhesive resin cement. RESULTS Over the 9-month follow-up period, no pulpal or periradicular pathology was observed on radiographs. Regarding the crown, the marginal fit was excellent, the anatomical form was protected, and no discoloration occurred. CONCLUSION During follow-up, the CAD/CAM PICN block endocrown proved to be a good material for the short- to long-term treatment of a primary tooth. However, more clinical cases and follow-up are required to investigate the long-term effects of antagonistic tooth wear.

Farkli cam iyonomer simanlarin kompozit ve kompomere olan makaslama bağlanma dayanim kuvvetlerinin karşilaştirilmasi

Amac: Bu calismanin amaci dort farkli cam iyonomer simanin kompozit ve kompomere olan makaslama baglanma dayanimlarini karsilastirmaktir. Gerec ve Yontemler: Calisma icin 80 adet silindirik sekilli akrilik blok hazirlandi. Bloklarin duz yuzeylerinin ortasina 2 mm derinliginde ve 3 mm capinda olan cukurcuklar acildi. Bloklar dort gruba ayrilarak acilan cukurcuklar Ionoseal (Ionoseal, Cuxhaven, Almanya), Ketac Molar (3M EPSE, Seefeld, Almanya), Equia (GC Avrupa, Tokyo, Japonya) ve Imicryl (Imicryl SC, Imicryl Dis Malz San. Tic. AŞ, Konya, Turkiye) marka cam iyonomer materyalleri ile dolduruldu. Standart yuzeyler elde etmek icin sertlesmeden once cam iyonomerlerin uzeri seffaf bant ile kapatildi. Sertlesme tamamlandiktan sonra cam iyonomer siman yuzeylerine tek asamali adeziv (Futurabond M, VOCO GmbH, Cuxhaven, Almanya) uygulandi ve polimerize edildi. Her bir grup 2 alt gruba ayrildi. Hazirlanan yuzeylerin uzerine yerlestirilen 2 mm yuksekliginde ve 2 mm capindaki aparatin icerisine tasmayacak sekilde doldurulan kompomer (Imicryl SC, Imicryl Dis Malz San. Tic. AŞ, Konya, Turkiye) ve kompozit (VOCO, Cuxhaven, Almanya) materyalleri uretici firmalarin tavsiyeleri dogrultusunda LED isik cihazi ile polimerize edildi. Universal test makinesi ile her bir ornekte kirilma meydana gelinceye kadar kuvvet uygulandi. Veriler iki yonlu varyans analizi ve Tukey coklu karsilastirma testleri ile istatistiksel olarak degerlendirildi (p=0.05). Bulgular: Ionoseal’ in kompozit ve kompomere olan makaslama baglanma degeri diger cam iyonomerlerden istatistiksel olarak daha yuksek bulundu (p 0,05). Sonuc: Rezin esasli cam iyonomer siman olan Ionoseal kimyasal sertlesen Ketac Molar, Equia ve Imicryl cam iyonomer simanlara gore daha yuksek makaslama baglanma degeri gostermektedir.

Is it possible to diagnose caries under fixed partial dentures with cone beam computed tomography

OBJECTIVE The goal of this study was to determine the possibility of detecting/diagnosing caries under fixed partial dentures using cone beam computed tomography. STUDY DESIGN A range of teeth with grade 3 to 6 caries, according to International Caries Detection and Assessment System criteria, were selected. All teeth were prepared, and three different specimens- zirconia full-ceramic, lithium disilicate full-ceramic, and metal-supported ceramic crowns-were built for each tooth. Each specimen underwent scanning by cone beam computed tomography. Opacity values were recorded and evaluated using two-way analysis of variance. The Tukey test was performed for material and slice differences, and the t test for mean gray value differences, between caries and noncaries regions of each material. RESULTS Significant differences were detected with respect to horizontal location (anterior/posterior), restoration type (crown/bridge), material (zirconia/lithium disilicate/metal), and situation (caries/noncaries) (P < .001). Mean gray values of caries and noncaries regions were found to differ for each material. There were no significant differences with respect to vertical position. CONCLUSIONS Cone beam computed tomography can be used as a posttreatment diagnostic technique for detecting caries under high-atomic-number fixed plate dentures. By combining high resolution and accuracy, cone beam computed tomography could provide the means for diagnosing caries without removing fixed plate dentures.

Management of an intruded primary central incisor with a natural crown under general anesthesia.

Tooth intrusion is the most common trauma during early infancy. Primary maxillary central incisors are the most affected teeth. There are a few treatment approaches which depend upon the severity of the trauma, and the treatment must be managed professionally. In this case report, a 3-year-old girl with a history of trauma 40 days before referring to our pediatric clinic is presented. Deciduous maxillary right central incisor was intruded through labial and alveolar socket and completely covered with soft tissue. The intruded deciduous incisor tooth was surgically extracted and impression was taken under general anesthesia. The removable partial prosthesis was completed by using the patient′s own extracted tooth. Using natural crown on removable prosthesis gives psychological satisfaction to the patient and his/her family, and can be better tolerated since its shape, size, and color are exactly in harmony.