Original Stone Research Articles

Style and Inscription

The practice of using classical capital lettering was introduced north of the Alps from Italy in the second half of the 15th century, and appeared very early in the Kingdom of Hungary. The article contains six case studies on the problems of architectural carvings, stone tabernacles, tombstones and the classical inscriptions on them. I. Tabernacles. All’antica tabernacles were produced in large numbers in late mediaeval Hungary and survive in churches from monumental to very small. The tabernacle frames, which followed the antique architecture of the façade, were accompanied by inscriptions: quotations about the Eucharist or, less frequently, inscriptions referring to the maker. II. Inscriptions outside the royal court. Outside the Buda residence of King Matthias, inscriptions engraved with humanist capitals also appeared, earlier than in the royal court, according to our present knowledge. The earliest dated inscriptions in Hungary survive in Veszprém and are attributed to Bishop Albert Vetési, the best known being a text written on ribbons running on a Gothic console (1467). The all’antica heraldic stones known from several places in the country are often dated, the earliest being found in the Nógrád castle of Miklós Báthory, the humanist bishop, with the date 1483. III. The royal court. Monumental all’antica inscriptions adorned the royal palace in Buda: building inscriptions, statue bases. Their texts are mostly known only from sources, as few original stone carvings have survived. These inscriptions were sometimes in bronze letters, but there were also engraved ones. The monumental inscriptions were associated with King Matthias, while the inscriptions known from the time of Vladislaus II are smaller in size and do not have bronze lettering. IV. Epitaphs. Antique letters also appeared as circular inscriptions on late medieval tombstones. The epitaph written in distychs was often engraved in a tabula ansata. Rarely, the wording was also antiquated, as exemplified by the abbreviations DOM, DOMS, DM. V. Inscriptions around Hungary in the Jagiellonian period. The commissioners of early inscriptions were familiar with the all’antica inscriptions of the Buda court. In Vienna, the first known all’antica inscriptions can be attributed to a citizen of Buda, Peter Juncker, and in Moravia to the lords of Tovačov and Moravská Třebová (Ctibor Tovačovský z Cimburka; Ladislav z Boskovic). VI. Architectural inscriptions of the Jagellonian period in Hungary. Inside the sepulchral chapel of Tamás Bakócz in Esztergom there is a bronze donation inscription (1507), in keeping with the perfect Renaissance centralised space. After 1500, all’antica building inscriptions became common in Hungary. We know of many of them, mainly in the Transdanubian region, written in pure classical capitals. In the northern part of the country, the early humanist capitals are more common; the Biblical quotations and proverbs on the staircase of the town hall of Bártfa were written in such letters. In Transylvania, classical capitals are again common: the inscriptions of the Lázói Chapel, built next to the cathedral in Gyulafehervár, or the Várday Chapel were also carved in such letters.

Tracing the biographies of textiles in the transition of medieval to modern times: Wool fabrics and brigandines from an Iberian castle

Findings of archaeological textiles and fibres in Northern Iberia are extremely rare. The occurrence of a set of textile fragments, dated between the 14th and 16th centuries CE at the Pambre castle (Palas de Rei, Lugo, Spain) is exceptional. The original stone roof of the southeastern tower was intact. The dark, cold and moist conditions inside the tower favoured the preservation of a unique series of waterlogged textile remains. In addition, a set of pseudomorphs preserved by mineral replacement were recovered from the east edge of the north wing in the main hall of the castle. Fibres have been identified using optical and scanning electron microscopy (SEM), and they have been chemically characterised using Energy Dispersive X-Ray Spectroscopy (EDX). We also performed analytical pyrolysis-GC-MS (Py-GC-MS) and thermally assisted hydrolysis and methylation (THM-GC-MS) of the wool fabrics and pseudomorphs to assess their state of degradation and the presence of chemical markers associated to the use of these textile remains. High performance liquid chromatography with diode array detection (HPLC-DAD-MS) and ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS/MS) analysis were applied on wool fabrics to identify the chemical markers of dyes but without success. To expand the information related to raw material identification and the technical aspects of the fabrics, further evidence such as adherences identified as opal phytoliths, seeds, and insect remains associated to wool fabrics were examined. These findings offer a unique glimpse into the clothing dated to the end of the Medieval period, and its life-cycle. Wool scraps were probably part of at least two different garments, whereas the mineralised textiles probably formed part of at least two brigandines which were made of bast fibres, flax, or hemp.

A robust superhydrophobic coating of siloxane resin and hydrophobic calcium carbonate nanoparticles for limestone protection

Hydrophobic calcium carbonate (CaCO3) nanoparticles (NPs), modified with dodecanoic acid (DA), are produced and dispersed in solutions of KSE 100, which is a silicic acid ester base product used for the conservation and maintenance of heritage and modern buildings. The dispersions are sprayed on limestone and marble specimens. By adjusting the relative concentrations of DA and NPs, the treated stones obtain superhydrophobic properties. Focusing on limestone it is reported that the treatment has negligible effects on the colour and vapour permeability of the original stone and offers protection against water capillary rise. Several studies are performed to test the durability of the composite (KSE + CaCO3-DA NPs) coating against rain impact, freezing and thawing, salt attack and UV radiation. Moreover, the mechanical, chemical and thermal durability of the coating is studied according to the tape peeling test, contact angles of drops which correspond to a vast range of pH, and heat treatment. The results of the aforementioned tests reveal the very good stability of the composite coating. In sum, it is reported that the wetting properties of the KSE 100 stone strengthener, which is used in building conservation, can be highly improved by adding a small amount of modified CaCO3 NPs. The latter are chemically compatible with calcareous stones.

Chemical Composition of Hydrophobic Coating Solutions and Its Impact on Carbonate Stones Protection and Preservation

The decay diagnosis and conservation of stone-built heritage is becoming a worldwide concern, especially when stone decay causes chromatic changes in the original stone aesthetics, which directly impacts its sociocultural value. Among all the causes of stone decay, water action is identified as the major cause of stone decay and chromatic changes in stone building materials; hence, protective eco-friendly hydrophobic coatings are the efficient and fundamental options to prevent penetrating water into the stone. This paper aims to contribute to tackling water action on natural building stones by studying three different commercial hydrophobic coatings and finding out the correlation between the effectivity, compatibility, and durability of these coatings and the physical, chemical, and mineralogical features of four distinct types of limestone, one calcitic dolomite, four kinds of marble, and one granitoid. Nine different natural stones have been chosen due to their variations in physical, chemical, and mineralogical natures. A multi-analytical approach was adopted through digital microscopy and colourimetry assays to assess the compatibility of the hydrophobic coatings, accelerating ageing in climatic chambers to assess their durability, optical tensiometer analyses to evaluate the hydrophobic effectiveness, and h-XRF and XRPD for determining the chemical and mineralogical composition of stone samples. The results obtained demonstrate that the coating composed of silane/siloxane with modified fluorinated additives (FAKOLITH FK-3 Plus Nano) is the most effective, compatible, and durable coating among the selected hydrophobic coatings. These results can be considered the pioneering steps for developing eco-friendly and cost-effective coatings.

The Architectural Façade Features of Traditional Nigde Houses that are Influential in the Formation of Urban Identity

Factors such as the change of societies living in cities, migration from village to city, unplanned urbanization, socio-economic and socio-political effects cause the emergence of new settlements in the city, as well as the rapid change and transformation of the local architectural identity that has been formed before. This situation causes cities to become ordinary, similar to each other and even the same, distancing from their original identities. One of the most important parts of the city, which is the object of memory and reflects the identity elements of a period, is the residential architecture. When the old and original neighbourhood textures formed by the Nigde houses are reviewed, it is seen that it was settled on the Kayabasi, Tepeviran and Alaaddin hills in the centre. It was observed that the garden walls and houses were placed by using the slope of the land from the hills to the plain and the planning was made without blocking the view and the sun, thus organic street textures emerged. It is seen that the original two-storey stone houses and organic street texture in the gardens, which constitutes the architecture of Nigde and its nearby villages (Yesilburc Village, Fertek Village, etc.), have been demolished in recent years due to the roads opened for vehicle traffic. Within the scope of the study, it is aimed to reveal the contribution of the architectural elements of the traditional Nigde houses, which constitute the urban identity and urban texture of Nigde and which is one of the biggest components of the urban life setup, to the urban identity.

Fragmenty Krocínovy kašny z Lapidária Národního muzea. Pohled restaurátora

Fragments of Krocín’s fountain from the Lapidarium of the National Museum – a restorer’s perspective Krocín’s fountain in Prague’s Old Town Square is an impressive and beautiful stone sculpture work from the second half of the 16th century. Its partial historical reconstruction is now part of the permanent exhibition “Stone Sculpture Monu­ments in Bohemia from the 11th to the 19th century“ in the Lapidarium of the National Museum. However, only part of the fragments taken over by the National Museum were used for the historical reconstruction in 1991, with another large part remaining stored in the Lapidarium’s depository. Given the planned reconstruction of the Lapidarium building, and the necessary intervention in the permanent exhibition, the question arises of whether it would be possible to display Krocín’s fountain on a larger scale in the future. The aim of this article is to evaluate the physical condition of the original stone fragments that were not used for the exhibition reconstruction. Twenty stone fragments from Krocín’s fountain underwent restoration and laboratory research. Finally, documentation is presented of the conservation of the two most damaged fragments, which were treated in collaboration with students of the Sculpture Workshop of the Academy of Fine Arts in Prague.

Роль культурных факторов в формообразовании каменных орудий в раннем Палеолите

Introduction. The original stone industries of the Early Paleolithic, produced by the earliest hominins and known as the Oldowan (~2.6-1.0 Ma), are characterized by rather primitive stone-working techniques and a very simple set of tools that show the intentional design of only workers and accommodators. elements. These industries have changed little in time and space and are not subdivided into variants due to cultural factors.Materials and Methods: The main sources of the work were massive historical documents related to the development of technology and protodesign in the early Paleolithic.Results. The Acheulean industries, which were made more advanced by early people, are distinguished by the appearance of more complex technologies and a whole range of tools of various shapes and purposes. Throughout the Acheulian era (~2.0-0.2 million years ago), these industries gradually developed, and also divided into local groups with specific technological repertoire and tool forms, which were almost completely modeled by ancient craftsmen according to their preferences and reproduced over time. This means the emergence of proto-design and cultural traditions, which are most reflected in the forms of the most important large tools, primarily the axe.Conclusion. Persistent tool patterns in different Acheulean industries can be seen as cultural types that mark distinct traditions. There are also individual samples of axes, the anomalous dimensions of which, along with extremely careful processing and some peculiarities of the form, suggest that they were not so much tools as some kind of symbolic objects that played a certain role in the cultural practices of different populations of the Acheulean people.

나주읍성 동점문 성벽부재에 대한 암석학적 연구 및 산지 추정

This study is based on the mentorship course in CNU Science Education Institute For the Gifted. The Naju Eupseong Dongjeommun Gate, which was built in the Goryeo Dynasty, was restored in 2002, but a heterogeneous stone material that showed a significant difference from the original stone of the fortress wall, was used as the restoration stone. This study aims to clarify the difference between raw stones and restored stones by the investigation of the petrological features of the stone materials for the Naju Eupseong Dongjeommun Gate, and to estimate the provenances of the raw stones through the geologic survey. In addition, replacement stones that can be used for when the Naju Eupseong Dongdaemun Gate is renovated are presented. As a result of measured magnetic susceptibility and visual observation, the stone materials of the Naju Eupseong Dongjeommun Gate consist of granodiorite, and granite gneiss. Compared to the original stone, the restored stone is judged to be a granite, which shows a clear difference in the petrographical features such as the results of visual observation and the magnetic susceptibility. As a result of the geologic survey around Naju Eupseong Walled Town, the area of Geumseongsan Mountain in Naju is presumed to be the source of the original stones. Granite diorite is considered appropriate as a substitute stone if the restoration of Naju Eupseong Dongjeommun Gate is carried out.

Jadeite original stone inspired PBA core-shell architecture endowed fire-safe and mechanic-robust EP composites with low toxicity

Epoxy resin (EP) has been favored in extensive fields. Nevertheless, the notorious issue of high fire hazard has been a nonnegligible bottleneck for its extended application. Here, a Jadeite original stone inspired PBA core-shell architecture (Co–Fe–Co PBA) is constructed towards fire retardation and toxicity elimination of EP. This architecture holds high strengths in physically blocking and chemically catalyzing towards released volatiles, leading to markedly impaired fire hazard. By using 2.0 wt% Co–Fe–Co PBA, the peak heat release rate and total heat release values are decreased by 40.2% and 33.8% whilst the peak smoke production rate and total smoke production are reduced by 43.7% and 35.2%. Also, the inhibited emissions of toxic gases including CO, NO and HCN, are discovered. Of note, the promotion in impact strength can be acquired. In brief, this work may be encouraging for the construction of PBA based hierarchical architecture, as cornerstones for fire-safe polymer composites with low toxicity.

Experimental thermo-hydric study to simulate natural weathering conditions

• Development of an experimental setup realistically reproducing thermo-hydric strain. • Estimation and localization of the generated thermo-hydric stress. • Comparison of stones through the assessment of long-term stone weathering. Laboratory aging tests allow to indirectly study stones behaviors on a monument. Classic aging tests are designed to compare materials resistance to different weathering mechanisms: they are more intense than the on-site conditions and do not reflect the real weathering intensity and kinetics. To study the real weathering on a monument and the materials behavior, an experimental setup using realistic experimental conditions was designed. The stones of a monument in Reims (France) were studied through this experimental setup: the Courville limestone (original stone) and the Savonnières limestone (restoration stone). The environmental variations were taken into account through a previous climatic monitoring of the monument. The realistic experimental setup was designed to reproduce, in a stone sample, the thermal and hydric strains experienced by a stone on a vertical wall. Temperature and humidity variations were applied unidirectionally through one surface, defined as the exposed surface. The temperature and humidity variations were based on typical variations identified with an in-situ monitoring of the basilica: sunny day, cold and warm rainy days, and frost day. The mild conditions, similar to the on-site conditions, did not visibly damage the samples and their behavior was studied through temperature and strain variations. The Courville limestone appeared more sensitive to the thermo-hydric variations of the typical days, particularly by the presence of water in the porous network than the Savonnières. Water generated high stress in the wet layer due to hydric expansion and at the wet/dry interface due to strain difference. Furthermore, the ice formation in the wet layer could induce high stress. On the contrary, the Savonnières limestone did not appear sensitive and little to no stress was generated during the typical days. The realistic setup allowed a simulation of the temperature and water repartitions in the samples close to on-site conditions. It provided relevant information in this specific environment and could help anticipate stone weathering on the monument.

Behaviour of Composite Structural Members Built-Up from Locally Available Stone Units Jacketed with Ferrocement

In this study, the traditional building system using locally available stone units is re-engineered by adding a ferrocement jacket to the original stone member. This technique did not only improve both the strength and behaviour of the new composite section, but also will be more economical by saving the land cost due to the reduced section width and extend the service life expectancy of the building. Nine types of stones were taken from different quarries in the North and West region of Iraq and were subjected to preliminary compressive strength tests to select three of them based on their grade of strength for further and more in-depth mechanical properties investigation to be used in building the structural members in this study.Both beam and column sections are investigated. The variables were the type of the stone used and the number of wire-mesh layers in the ferrocement jacket. The results indicate that regardless the type of stone used, weak medium or strong, the number of wire-mesh layers is the dominant parameter and the more the number of wire-mesh layers the more strength and better behaviour is resulted. Using 6-layers of wire-mesh in the ferrocement jacket led to an increase in the beam ultimate flexural strength of 245.9% and column axial compression strength of 94.3%. In addition, stiffness, ductility, toughness, and mode of failure are also investigated and shown to be improved with ferrocement jacketing.

Nano‐silica/fluorinated polyacrylate composites as surface protective coatings for simulated stone cultural relic protection

AbstractStone cultural relics are widely distributed globally and have significant historical and cultural significance and research value. However, most of them have suffered severe weathering and erosion due to the physical and chemical effects of different climatic conditions. Herein, a series of nano‐silica/fluorinated polyacrylate composites as surface protective coatings to protect simulated stone cultural relics were prepared with dodecafluoroheptyl methacrylate (DFMA), acrylates, and different contents of nano‐silica. The storage stability, mechanical stability, coagulum rate, and surface tension of the composite coatings were measured. The UV absorption, chemical structure, surface morphology, and thermal properties of composite films were characterized. When the nano‐silica content was 6 wt%, the optimal nano‐silica/fluorinated polyacrylate (Si‐F‐3) composite with excellent comprehensive properties was applied in the protection of simulated stone cultural relics. Compared with the uncoated original stone samples, the simulated stone cultural relics treated with Si‐F‐3 composite not only had freeze–thaw resistance but also could slow down sulfate erosion and freeze–thaw coupling cycle (SEFTCC) test damage. To conclude, the nano‐silica/fluorinated polyacrylate composites could be a desirable solution for protecting stone cultural relics.

Geochemical Data from Polynesian Artifacts Pack Pofatu Database

A new resource may help match artifacts with their original stone sources—“a really a niche part of archaeology that requires geological expertise.”

Ancient Stone Inscription Image Denoising and Inpainting Methods Based on Deep Neural Networks

Chinese ancient stone inscriptions contain Chinese traditional calligraphy culture and art information. However, due to the long history of the ancient stone inscriptions, natural erosion, and poor early protection measures, there are a lot of noise in the existing ancient stone inscriptions, which has adverse effects on reading these stone inscriptions and their aesthetic appreciation. At present, digital technologies have played important roles in the protection of cultural relics. For ancient stone inscriptions, we should obtain more perfect digital results without multiple types of noise, while there are few deep learning methods designed for processing stone inscription images. Therefore, we propose a basic framework for image denoising and inpainting of stone inscriptions based on deep learning methods. Firstly, we collect as many images of stone inscriptions as possible and preprocess these images to establish an inscriptions image dataset for image denoising and inpainting. In addition, an improved GAN with a denoiser is used for generating more virtual stone inscription images to expand the dataset. On the basis of these collected and generated images, we designed a stone inscription image denoising model based on multiscale feature fusion and introduced Charbonnier loss function to improve this image denoising model. To further improve the denoising results, an image inpainting model with the coherent semantic attention mechanism is introduced to recover some effective information removed by the former denoising model as much as possible. The experimental results show that our image denoising model achieves better results on PSNR, SSIM, and CEI. The final results have obvious visual improvement compared with the original stone inscription images.

Analysis on Material Characteristics of Restored Areas with Mortar and Basis of Surface Deterioration on the Stupa of State Preceptor Jigwang from Beopchensaji Temple Site in Wonju, Korea

The Stupa of State Preceptor Jigwang from Beopcheonsa Temple Site in Wonju (National Treasure) is a representative stupa of the Goryeo Dynasty, with outstanding Buddhist carvings and splendid patterns, clearly indicating its honoree and year of construction. However, it was destroyed by bombing during the Korean War (1950-1953) and repaired and restored with cement and reinforcing bars in 1957. The surface condition of the original stone shows long-term deterioration due to the m ortar used in past restorations. In order to identify the exact causes of deterioration, the m ortar and surface contaminants on the original stone were analyzed. Portlandite, calcite, ettringite, and gypsum from the mortar were identified, and its ongoing deterioration was observed through pH measurements and the neutralization reaction test. Analysis of surface contaminants identified calcite and gypsum, both poorly water-soluble substances, and their growth in volume among rock-forming minerals was observed by microscopy. Based on those results, semi-quantitative analysis of Ca and S contents significantly influencing the formation of salt crystals was conducted using P-XRF to analyze the basis of surface deterioration, and cross-validation was performed by comparing the body stone affected by the mortar and the upper stylobate stone unaffected by the mortar. Results indicate that the elements are directly involved in the surface deterioration of the body stone.

Novel Approach for Reinforcement the Extraction of ECG Signal for Twin Fetuses Based on Modified BSS

One of the most used traditional method to measure heart conductivity of fetal is the fetal Electrocardiography (FECG). Many indicators related to the health of fetal can be determined depending on FECG since fetal heart rate (FHR) is obtained from the components of FECG signal. Recording fetal ECG in a clinic forms a problem due to the interferences of other signals which corrupt the ECG signal. Another problem happen as a result to the location of the used electrodes for recording ECG since these electrodes are placed on the mother abdomen. The obtained abdominal ECG signal also contain different types of interferences. The maternal ECG represents the first big interference source with the FECG signal. Breathing, the activity of mother's muscle, electrode contact with the mother's skin, power line interference and thermal noise, all of them represent a possible noise source. In case of extraction ECG signal for twin gestation, clear FECG for every single fetal would be more difficult because in addition to the all mentioned source of interferences and noise, both fetuses may share the same morphology and FHR. Close monitoring to the heart of twin is required for early diagnose of congenial problems which infect heart. In this study a novel approach has been made by combining conventional Stone BSS and particle swarm optimization (PSO) to produce (MSBSS). The obtained results are compared with other two BSS algorithms (EFICA and JADE) in addition to the obtained results using conventional Stone BSS. MSBSS method has revealed better performance comparing with the other BSS techniques including original Stone BSS.

A New RFID-Identification Strategy Applied to the Marble Extraction Industry

This paper aims to improve the marble industry production chain by proposing new technological approaches using the Radio Frequency Identification (RFID) systems. The dynamic capabilities of the RFID read-write tags allow the storage of physical characteristics of stone blocks, according to electrical, ultrasound and three-dimensional image characterization tests. These characterization non-destructive tests allow the evaluation of important parameters of the original stone blocks, by analyzing the internal structure of the rocks. Then, these parameters can be stored in databases through RFID-tags, in order to optimize their subsequent cutting and transformation processes. RFID identification technology when integrated into an ethernet communication network enables automatic communication with cutting and processing equipment, building an intelligent industrial platform, integrating PCs (Personal Computers) and PLCs (Programmable Logic Controllers) within an Industry 4.0 environment. Another huge advantage of RFID technology is that it allows full product traceability, namely by enabling the end consumer to reverse the production path. A laboratory prototype was implemented and a detailed analysis and discussion of the obtained functionalities is shown at the end of this paper.

Alkali activated materials using pumice from the Aeolian Islands (Sicily, Italy) and their potentiality for cultural heritage applications: Preliminary study

In this paper, the potentialities of pumice-based geopolymers have been explored with the aim to evaluate their use as restoration materials. In particular, the behaviour of Aeolian pumice during alkali activation process, either alone or in binary mixtures with metakaolin, has been assessed using sodium hydroxide and sodium silicate activators. Hardened products were characterized by: X-ray diffraction; infrared spectroscopy; thermo gravimetry and electron microscopy. Furthermore, Hg-intrusion porosimetry, water absorption, compressive strength and colorimetric measurements were carried out in order to define the technical features of the produced geopolymers. The results reveal that Aeolian pumice mixed with small quantities (20–30 wt%) of metakaolin is suitable for the formation of lightweight geopolymers which exhibit an accessible porosity up to 30%, water absorption of about 18.0%, and satisfactory 28-day compressive strength up to 12 MPa. These values indicate good breathability and adaptability to the substrates of the proposed formulations. Final products display a homogeneous and compact amorphous matrix, and their colour mimic the original stones, highlighting their potential role in Cultural Heritage preservation.

AK MEDRESENİN (NİĞDE) YAPIMINDA KULLANILAN TAŞLARIN MÜHENDİSLİK ÖZELLİKLERİ VE SORUNLARI

Ak Medrese (Niğde) 1409-1410 yılında Karamanoğlu hükümdarı Alâeddin Ali Bey’in oğlu Ali Bey tarafından yaptırılmıştır. Bazı onarımlar görerek günümüze kadar gelen medrese, orijinal durumunun muhafaza etmekte olup, dönem medrese yapıları arasında en önemlilerinden birisidir. Yapı, Cumhuriyet döneminden itibaren farklı amaçlar için kullanılmaktadır (okul, müze deposu, kütüphane vb.). Bu tür yapıların korunması ve gelecek nesillere aktarılması için bakımlarının düzenli bir şekilde yapılması gerekmektedir. Bu çalışmada yapıda kullanılan taşların jeomekanik özellikleri ve sorunlarının belirlenmesi amaçlanmış olup, alınan üç örnek üzerinde taşların karakteristik özellikleri belirlenmiştir. Yapıda temel seviyesine yakın kesimlerdeki yapı taşlarında zemin suyuna bağlı olarak önemli oranda bozunmalar gözlenmiştir. Anıtta restorasyon aşamasında gerçekleştirilen drenaj uygulamasından sonra da anıtın bazı kesimlerde zemin suyu ile ilişkili olarak renklenme, çiçeklenme ve taşın dayanımın azalması sonucunda yüzeysel ve bazı kesimlerde oldukça önemli miktarda taş kayıpları gözlenmiştir. Restorasyon uygulamalarında yörenin orijinal taşının kullanılmadığı belirlenmiş olup, yerine kullanılan restorasyon taşların özellikle kapiler bölgede bozunma sürecini hızlandırdığı belirlenmiştir.

Comparison of the Accuracy of Three-Dimensional Printed Casts, Digital, and Conventional Casts: An In Vitro Study.

Objectives The integration of computer-aided design and manufacturing technologies in diagnosis, treatment planning, and fabrication of prosthetic restoration is changing the way in which prosthodontic treatment is provided to patients. The aim of this study was to compare the accuracy of three-dimensional (3D) printed casts produced from the intraoral scanner using stereolithographic (SLA) 3D printing technique, their digital replicas, and conventional stone casts. Materials and Methods In this in vitro study, a typodont of maxillary and mandibular arches with full dentate ivory teeth was used as a reference cast. The typodont was digitized using Trios 3Shape intraoral scanner to create digital casts. The digital files were converted into 3D printed physical casts using a prototyping machine that utilizes the stereolithography printing technology and photocurable polymer as printing material. Linear measurements (mesiodistal and occlusocervical) and interarch measurements (intercanine and intermolar) were made for digital and prototyped models and were compared with the original stone casts. The reference teeth were canines, first premolars and second premolars in the maxillary and mandibular arches on the right and left sides. The measurements on printed and conventional casts were done by digital caliper while on digital casts; Geomagic Qualify software was used. Statistical Analysis One-way analysis of variance (ANOVA) was used to compare measurements among groups. Results Digital casts showed significantly higher error than the other two groups in all linear and interarch measurements. The mean errors of the digital cast in occlusocervical (OC) and mesiodistal (MD) measurements (0.016 and 0.006, respectively) were higher compared with those in the other two groups (OC, 0.004 and 0.007 and MD, 0.003 and 0.005 [ p < 0.0001 and p = 0.02, respectively]). Also, digital mean error in intermolar width (IMW) and intercanine width (ICW) (0.142 and 0.113, respectively) were greater than the other two groups (IMW, 0.019 and 0.008 and ICW, 0.021 and 0.011 [ p < 0.0001]). However, the errors were within the acceptable clinical range. Conclusion The 3D printed casts may be considered as a substitute for stone casts with clinically acceptable accuracy that can be used in diagnosis, treatment planning, and fabrication of prosthetic restorations.