Lost-wax Research Articles

Comparison of the influence of different cements on the compressive strength of Nickel chromium coping and Zirconium oxide coping- An invitro study

Strength and biocompatibility of any restoration is an important criterion for success and function of any prosthesis. Despite the high fracture resistance of traditional metal ceramic crowns, limitations are imposed by esthetic concerns. The objective of this study is to determine whether zirconium dioxide or nickel chromium copings had better strength when used with two resin based luting cements namely RelyX U100 and Variolink II. Materials and Methods: A total of 40 copings were fabricated, of which 20 were zirconium oxide copings made using CAD/CAM technology. The remaining 20 were nickel-chromium copings obtained using Lost Wax technique. Two resin cements were selected i.e, RelyX U100 universal selfadhesive resin luting cement (RelyXTM U100, 3M ESPE, Sumar´e, SP, Brazil) and Variolink II resin luting cement (Ivoclar Vivadent, Schann, Liechtenstein). These cements were mixed and luted on the copings. The copings were seated onto the steel die using finger pressure for 1 minute and placed under a 2.2 kg standard load for 15 minutes. A compressive load was applied through a 1/8-inch diameter hardened steel sphere attached to the moving head of universal testing machine (LR 50K, Lloyds instruments, UK). Load was applied at a crosshead speed of 0.5 mm per minute until fracture occurred. Results: It was found that Nickel-Chromium yielded a higher fracture load compared to Zirconia and the difference in mean fracture load between them was found to be statistically significant (P Copings are found to be a significant factor influencing fracture load. No statistically significant difference was observed between RelyX and Variolink II cements (P>0.05). Slightly higher mean fracture load was recorded in Variolink II compared to RelyX. Keywords: Variolink II, RelyX U100, Nickel-Chromium, Zirconium dioxide.

Structure, physical and mechanical properties of bronze castings obtained by continuous and centrifugal casting

The influence of crystallization conditions (continuous and centrifugal casting) of small-sized BrА1Fe4Ni4 bronze castings on the structure, phase composition, and hardness was studied. It was found by metallographic and X-ray diffraction methods that the castings consist of (α + γ')-eutectoid, α phase and AlCu, Al2Cu3 intermetallic compounds. The matrix phase in the alloy, crystallized by centrifugal casting, due to its higher alloying with Al atoms, has an increased value of the crystal lattice parameter, compared with the case of continuous casting. The hardness of the casting obtained by centrifugal casting increases compared with continuous casting, which is due to the formation of a more dispersed structure, as well as a large solid solution hardening of the matrix phase of the casting.

Design, fabrication and characterization of soft sensors through EGaIn for soft pneumatic actuators

Abstract At present, very few soft actuators have achieved strain and pressure sensing capabilities simultaneously. In this paper, one kind of soft strain and pressure sensors based on liquid conductive metal (EGaIn) are proposed, which can be integrated into typical soft pneumatic actuator easily for sensing functions. Here we report design models, fabrication techniques, sensing characterization and sensation experiments for the potential sensors. Especially for EGaIn-based strain sensors, sensitivity is improved greatly (up to 28.6–~30.8) realized via embedded fibers, and low hysteresis (2.23%) and high repeatability (loading: ±0.92% and unloading: ±1.34%) are further demonstrated. Also, we explore a novel embedded channels-manufacturing method called lost-wax casting, which could overcome fabrication complexity, possible leakage and low manufacturing success rate dramatically. Finally, our experimental demonstration utilized the sensorized actuators to detect the profiles, sizes and softness of objects and obtained desired results like a real finger.

Fabrication and Characterization of the Newly Developed Superalloys Based on Inconel 740

The chemical composition of standard Inconel 740 superalloy was modified by changes in the Al/Ti ratio (0.7, 1.5, 3.4) and addition of Ta (2.0, 3.0, 4.0%). Remelted Inconel 740 (A0) and nine variants with various chemical compositions were fabricated by lost-wax casting. The microstructure, microsegregation, phase transformation temperatures, thermal expansion coefficients and hardness of the superalloys were investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy, differential scanning calorimetry, dilatometry and Vickers measurements. Typical dendritic microstructure was revealed with microsegregation of the alloying elements. Segregation coefficient ki for Ti, Nb and Ta did not exceed unity, and so precipitates enriched mainly in these elements were found in interdendritic spaces. The Nb-rich blocky precipitates, MC carbides, MN nitrides, oxides, and fine γ’ was in all modified castings. Presence of other microstructural features, such as Ti-rich needles, eutectic γ-γ’ islands, small Al-rich and Cr-rich precipitates depended on the casting composition. The lowest solidus and liquidus temperatures were observed in superalloys with a high Al/Ti ratio. Consequently, in A7–A9 variants, the solidification range did not exceed 100 °C. In the A0 variant the difference between liquidus and solidus temperature was 138 °C. Hardness of all modified superalloys was at least 50% higher than for the remelted Inconel 740 (209 HV10).

Polyethylene Wax Modified by Organoclay Bentonite Used in the Lost-Wax Casting Process: Processing-Structure-Property Relationships.

In this paper, the influence of bentonite (BNT) on rheological properties, linear shrinkage, hardness, and structure of polyethylene wax (PE-wax) used in the lost-wax casting process are studied. Experiments were conducted with PE-wax with different contents of bentonite (from 0.1 to 5 wt.%). The structural changes of modified polyethylene wax were evaluated using differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The addition of bentonite in a concentration range between 0 and 0.8 wt.% into PE-wax caused a decrease of the linear shrinkage and the hardness of PE-wax/BNT blends. Modified polyethylene wax containing greater than 1 wt.% of the filler showed an increase in viscosity. The DSC-based investigations confirmed good miscibility and a uniform structure of PE-wax with BNT. Moreover, an increase in melting temperature onset and its enthalpy observed for filler PE-wax material showed an influence of bentonite on the crystalline structure of the polymeric matrix. SEM observations of the fractured surfaces confirmed the homogeneous structure of blends with contents up to 0.8 wt.% BNT. In the case of higher filler concentrations, the presence of more numerous and large clusters of filler in the polymer matrix was observed due to the increase in the viscosity of the PE-wax/BNT melt composition during mixing. The PE-wax blend with 0.4 wt.% BNT gives better results of reduced linear shrinkage and lower hardness than unmodified material. Lastly, a new developed material (PE-wax/0.4 BNT) was subjected to technological tests, consisting of the preparation of the mold and manufacture of a high-quality aluminum cast, using the lost-wax method.

«BIRD-HEAD» OR «HORSE-HEAD» SCEPTRES — A REAL OR APPARENT DILLEMA?

«BIRD-HEAD» OR «HORSE-HEAD» SCEPTRES — A REAL OR APPARENT DILLEMA?

Thermodynamic study of the acid-induced decontamination of waste green sand generated in a brass foundry.

Waste foundry sand (WFS) from the brass and bronze casting and molding process include various potentially toxic elements (PTEs), such as copper, zinc, tin, and lead. Hence, the utilization of WFS in construction and geotechnical applications evokes environmental concerns due to the rain-induced leaching of PTEs into the groundwater system. The present study investigated the extractive decontamination of WFS using mineral acids, e.g., HCl, H2SO4, or HNO3. Favorable extraction efficiency was achieved with HCl as compared to the other mineral acids, which was further enhanced at high temperatures and increased acid concentrations. The thermodynamic analysis indicated that ≥ 4molL-1 of HCl and ≤ 100°C temperature ensured maximum extraction of PTEs due to the endothermic interactions between the HCl and PTEs. The HCl-treated WFS needed to be rinsed with water to restrict the after treatment elution of PTEs. The hazardous environmental impact of acid-treated WFS was evaluated following the standard leaching test and comparison with legislative recommendations for PTEs, which showed the water-assisted leaching rate of all the PTEs are within the regulatory limits.

Towards the Problem of Construction an SPD Stress-Strain Curve for Low-Plastic Materials

Stress-strain curve construction for low-plastic alloys under severe plastic deformation conditions is considered. A material under investigation is cast bronze Cu85-Pb5-Sn5-Zn5. Experiments on upsetting and deep rolling were conducted. Based on these data, the initial hardening modular and the hardening modular at large strain were evaluated. Classic tests on determining an initial segment of stress-strain curve can lead to grate mistakes because shear band sliding can diminishes appreciably both yield stress and hardening modular. A correct methodology for stress-strain curve construction is proposed.

Study on microstructure control and performance optimization of ZCuPb20Sn5 alloy by rare earth la

ZCuPb20Sn5 alloy is a cast lead-tin bronze alloy. Due to its high lead content, it has excellent comprehensive properties such as friction reduction and wear resistance, high fatigue strength, good thermal conductivity, and good wear resistance. It is widely used in automobiles, Aerospace industry and other fields. Therefore, this article selects ZCuPb20Sn5 alloy as the research object. By adding rare earth La to ZCuPb20Sn5 alloy solution, the metallographic structure and mechanical properties are observed, and the effect of rare earth La on the microstructure and properties of ZCuPb20Sn5 alloy material is analyzed. The results show that with the increase of La content, the tensile strength, elongation and hardness of lead-tin bronze alloys all increase first and then decrease. Without the addition of rare earth lanthanum, the tensile strength of lead-tin bronze can reach about 241.5 MPa. Adding different amounts of rare earth to the lead-tin bronze alloy can improve the tensile strength and elongation of the alloy. When 0.04 wt.% rare earth lanthanum is added, The strength and elongation reached the maximum. After several experiments, the tensile strength remained at about 267.1, the elongation remained at about 15.13%, the tensile strength increased by about 25.6 MPa, and the hardness remained at about 80 HB, with little increase.

Digital evaluation of laser scanning speed effects on the intaglio surface adaptation of laser-sintered metal frameworks

Statement of problemLaser sintering has several processing parameters, typically under the control of dental laboratory technicians. Laser scan speed is an important parameter, which has a significant effect on manufacturing time but may also affect the adaptation of restorations. However, limited information is available regarding its impact. PurposeThe purpose of this in vitro study was to evaluate the intaglio surface adaptation of laser-sintered cobalt-chromium single-crown frameworks sintered at laser scanning speeds of 1, 3, and 6 m/s. Material and methodsA master bronze metal die was prepared and scanned by using a laboratory scanner to fabricate the metal frameworks for 4 groups (n=10). In group C, the frameworks were fabricated by using the lost-wax method (control). In group L1, L3, and L6, the frameworks were fabricated by using direct metal laser melting (DMLM) at laser scanning speeds of 1, 3, and 6 m/s. After fabrication, 3 scanning data sets were used to evaluate the intaglio surface adaptation: the master die, the intaglio surface of each metal framework, and each metal framework seated on the master die. The intaglio surface adaptation of the metal frameworks was evaluated by using a metrology software program. The data were statistically analyzed by using a 1-way ANOVA, the Tukey honestly significant difference test, and the Tamhane T2 test (α=.05). ResultsThe highest mean intaglio surface discrepancy value was obtained from group L6, and this was significantly different from the other 3 groups (P<.001). No significant intaglio surface discrepancy differences were found among the other groups. ConclusionThe amount of intaglio surface discrepancy increased when the laser scanning speed reached 6 m/s.

Lancaster Pet Cemetery Memorial Plaques 1951–2018: An Analysis of Inscriptions

ABSTRACTIndividuals in many cultures have a close relationship with their pets and think of them not only as companion animals but also as family. Research on the ways in which people memorialize their deceased pets has become increasingly important, and pet cemetery gravestone inscriptions have provided a way to examine the evolution of the human–animal bond. Past studies of the inscriptions on gravestones have been largely qualitative, whereas our longitudinal study of the 2,695 memorial plaques from 1951 to 2018 in the Lancaster Pet Cemetery in the United States allows for a quantitative analysis of the inscriptions and what they reveal about pets, owners, and people’s relationship with their pets over time. The results showed that nearly all plaques listed the pet’s name as well as the pet’s year of birth and year of death. Identifying the type of pet on the plaque increased over time as did the use of a bronze cast or picture to identify the type of pet, nearly all of which were dogs or cats. The use of gendered human names for pets increased over time, particularly for families and male-female couples. The types of owners remained relatively stable over time, with about two-thirds of pets belonging to families and male-female couples; however, the way in which owners listed themselves on the plaques changed over time. Words on the memorial plaques that increased over time included “love/loved,” “you,” “Mommy/Daddy,” and “missed,” and described the owner relative to the pet or feelings about it. On the other hand, the word that decreased most over time was “pet.” For the most part, there was little variation in the words by type of pet or type of owner. Many of the findings signaled an increasing tendency for people to think of their pets as family. Suggestions for future research are also included.

Design and Mechanical Characterization of Voronoi Structures Manufactured by Indirect Additive Manufacturing.

Additive manufacturing (AM) is a production process for the fabrication of three-dimensional items characterized by complex geometries. Several technologies employ a localized melting of metal dust through the application of focused energy sources, such as lasers or electron beams, on a powder bed. Despite the high potential of AM, numerous burdens afflict this production technology; for example, the few materials available, thermal stress due to the focused thermal source, low surface finishing, anisotropic properties, and the high cost of raw materials and the manufacturing process. In this paper, the combination by AM of meltable resins with metal casting for an indirect additive manufacturing (I-AM) is proposed. The process is applied to the production of open cells metal foams, similar in shape to the products available in commerce. However, their cellular structure features were designed and optimized by graphical editor Grasshopper®. The metal foams produced by AM were cast with a lost wax process and compared with commercial metal foams by means of compression tests.

A new way to obtain NiTi SMA superelastic meshes: investment casting followed by hot rolling

In this work, NiTi superelastic meshes are manufactured through plasma melting followed by an injection into a mesh ceramic coating mold obtained by the lost wax technique. This is the first time such a manufacturing sequence is reported for NiTi SMA. Focus is given to the feasibility and efficiency of the manufacturing process. The as-cast NiTi meshes were afterward heat-treated and hot-rolled for thickness reduction and to increase malleability. After manufacturing, the meshes’ thermomechanical properties were characterized. Differential scanning calorimetry showed that at room temperature the NiTi meshes can either be used as thermal actuators (using the shape memory effect) or as superelastic devices, depending on whether heating or cooling is performed prior to the application. This behavior leaves great potential for applications in engineering systems and biomedical uses. The superelastic behavior of the NiTi meshes was characterized through tensile tests at room temperature, showing very good cycling stability and strain recovering up to 4%. In the future, microstructural and biocompatibility investigations of the product will be evaluated to optimize the manufacturing process.

Long-term clinical outcome of posterior metal-ceramic crowns fabricated with direct metal laser-sintering technology

ObjectivesTo evaluate the long-term clinical outcome of posterior metal-ceramic crowns fabricated with CAD/CAM-based laser-sintering technology (BEGO Medical, Bremen, Germany). Materials and MethodsSixty posterior crowns were placed in 39 patients. After tooth preparation, impression taking and model casting, the stone dies were scanned to create STL data, followed by manufacturing of crown frameworks with laser-sintering technology. A base metal alloy (CoCr) and a precious alloy (AuPt) were used for 31 and 29 posterior crowns, respectively, which were veneered using the layering technique. All crowns were cemented using glass-ionomer cement. ResultsThe mean observation period was 10.5 ± 3.9 years. Six patients with 10 crowns were regarded as dropout. Nine crowns had been removed, three of them were intact but they were removed due to a new prosthetic treatment plan. The cumulative survival rate of all crowns was 81% after 14.7 years. When comparing the survival rates related to the alloy used, the Gehan-Wilcoxon test showed no significant differences between both alloys. Biological complications were most commonly reported, while technical complications did not affect the function of the crowns. ConclusionThe long-term clinical outcome of posterior metal-ceramic crowns fabricated with CAD/CAM-based laser-sintering technology is very promising, so that this novel technique could be an alternative to the traditional lost wax casting process.

Effects of the Thickness Ratio of Zirconia-Lithium Disilicate Bilayered Ceramics on the Translucency and Flexural Strength.

To determine the effects of the total thickness and core/veneer thickness ratio of bilayered ceramics on their three-point flexural strength and translucency. Two groups of specimens were prepared with two different total thicknesses, 1.0 mm and 0.6 mm. These groups were divided into five and three subgroups with ten specimens each, respectively, having different core/veneer thickness ratios. Lithium disilicate was pressed on the zirconia surface using the "lost-wax technique." The translucency and three-point flexural strength were measured, and a one-way analysis of variance test (p < 0.05) was performed to determine whether the translucency and three-point flexural strength were affected by the total thickness and core/veneer thickness ratio of the specimens. For the same total thickness, translucency decreased with a increase in the zirconia core proportion (p < 0.001). For the same core/veneer ratio, the translucency decreased with an increase in the total thickness (p < 0.001). If the zirconia thickness was less than half of the total thickness, the bilayered ceramic specimens containing zirconia cores and monolithic lithium disilicate specimens exhibited a similar translucency. The three-point flexural strength increased with the increasing proportion of zirconia; however, it did not change significantly with the total thickness. However, for the same total thickness, the flexural strengths of the bilayered ceramics were higher than those of the monolithic specimens. At the same total thickness, increasing the zirconia core thickness decreased the translucency and increased the three-point flexural strength. Bilayered ceramic specimens with low zirconia ratios exhibited translucency similar to that of monolithic lithium disilicate ceramic but a higher flexural strength.

Adorning the Body, Asserting Status: Prestige-Goods and Social Distinction at Ancient Chadic Chiefdom of Houlouf (Northern Cameroon)

Copper and alloyed copper artefacts, carnelian and glass beads have been recovered in archaeological excavations since the middle of the 20th century in the Chadian plain in northern Cameroon, northeastern Nigeria and southwestern Chad Republic. The initial research projects conducted by Marcel Griaule and Jean-Paul Lebeuf resulted in the “creation” of the Sao Civilization, characterized by a relatively high level of art craftmanship. They made impressive large pottery vessels, terracotta figurines, iron objects, and copper and alloyed copper artefacts, called “Sao Bronzes”. These artefacts were generally analysed from their supposed artistic characteristics; production techniques – the lost wax technique – were addressed but no metal production features were ever recorded in the first decades of research on northernmost Cameroon mounds. The Houlouf archaeological project conducted from 1981 to 1991 allowed for a better understanding of the production and use of the copper/alloyed copper artefacts and other prestige goods recovered from archaeological contexts. They range widely in nature, forms, and shape. There are ordinary personal adornment items – finger-rings, arm-rings, and ankle rings, necklaces, waist-beads – to very specialized cavalry – leg-guards – and archery – arm-bands -, including exceptional figurines. This contribution brings to light the context of use and socio-political implications of these prestige artefacts and outlines their meaning in the developing Central Sudan long-distance trade networks.

Производственные участки на поселении ранней бронзы Старый Тартас-5 (Барабинская лесостепь)

В статье представлены результаты исследования участков со следами бронзолитейного производства на поселении одиновской культуры Старый Тартас-5 в Барабинской лесостепи. Рассмотрены два участка: один — на территории жилища № 1 — с очагом и ямами, расположенными вблизи теплотехнического устройства, другой — за пределами этого жилища — с плавильным горном. Даются характеристика объектов и информация об археологическом контексте находок. В работе приведены полные описания каждого предмета литейного комплекта производственной оснастки, аналоги этих находок, результаты бинокулярного анализа формовочных масс. На основе данных термогравиметрических исследований установлены функциональная принадлежность обломков технической керамики и кратность использования различных предметов литейного комплекта. Отмечено, что тигли в виде прямостенных баночек известны только по одному целому изделию из погр. № 286 могильника Тартас-1; в составе поселенческих комплексов одиновской культуры они ранее не встречались. Определены специализация жилища № 1 указанного поселения на бронзолитейном производстве и специфика организации данного производства как индивидуально-семейного. Подчеркнуто, что традиции бронзового литья одиновской культуры сохранились в традициях кротовской культуры и пополнились новациями: типичные для одиновской культуры тигли в виде овальных чашечек носители кротовской культуры в соответствии с особенностями своего производственного процесса делали с более толстым дном. Одиновские комплексы Барабинской лесостепи датируются в пределах первой половины III тыс. до н.э. Сделан вывод о том, что свидетельства бронзолитейного производства, выявленные на памятнике Старый Тартас-5, являются самыми ранними для данного региона, уровень этого производства у носителей одиновской культуры был высоким.

Бронзолитейный комплекс поселения одиновской культуры Марково-2

Purpose. Metalworking production of the Early Bronze Age in Western Siberia is discussed in this article. Results. The first signs of local production can be traced to the beginning of the third millennium BC in Odino culture settlements occupying a vast area of the Ob-Irtysh forest-steppe. At present, foundry production has been identified at Stary Tartas-5, Tartas-1 and Markovo-2 settlements. The materials of the first two complexes have been published. This article is devoted to the introduction of the Markovo-2 bronze casting complex, examination of the archaeological context of finding materials, and description of the structure and objects inside it. The traces of intensive foundry activity were found in only one dwelling at the settlement. This can be explained by specialization and concentration of production in the hands of certain groups within the settlement population. Planigraphic and stratigraphic analysis make it possible to reconstruct this dwelling as a surface structure with a slightly elongated oval shape. The production complex consisted of a smelter and a utility pit located in the central part of the dwelling. The finds from the filling are represented by fragments of at least five clay molds and two melting pots. For each bronze casting item, a complete description, data from binocular analysis of molding masses, analogies and reconstruction of the manufacturing method are provided. Conclusion. Based on the research, it was concluded that the metalworking traditions, techniques, equipment and tools formed in Odin culture are spread over the vast territories of the Siberian forest-steppe zone and continue to exist within Krotovo culture. The Odino sites in the Baraba forest-steppe date to the first half of the third millennium BC. It is concluded that the evidence of the bronze casting industry found at Markovo-2 is the earliest in that region, and that its level in Odino culture was high.

Marginal and internal fit evaluation of conventional metal-ceramic versus zirconia CAD/CAM crowns.

The purpose of this in vivo study was to compare the marginal and internal gap widths of monolithic zirconia crowns fabricated by CAD/CAM technique and metal-ceramic crowns fabricated by conventional technique. 10 participants needing a single restoration were selected. Zirconia crowns using CAD/CAM technology (Group A) (n=10) and metal-ceramic crowns (Group B) (n=10) using lost wax casting technique were fabricated for each selected tooth. The marginal and internal gaps of crowns were recorded using a replica technique with light body silicone material stabilized with a regular set putty. Each replica was sectioned buccolingually and mesiodistally and then evaluated at five pre-determined sites. The points measured were PM for marginal gap, PA for axial gap, PAO for axio-occlusal transition gap and PO and PCO for occlusal gaps using a stereomicroscope at 30× magnification. The Paired Sample (t) test was used to detect significant differences between the two groups in terms of marginal and internal fit (α= 0.05). The mean for the marginal gap was 77.42μm (±39.5μm) for Group A compared with 95.86μm (±55.12μm) for Group B. Mean values for internal gap was 87.24 (±21.7 µm) for Group A and 132.91 µm (± 50.63 µm) for Group B. Significant differences were observed between both the groups for marginal (p=.010) and internal (p=.000) fit. The CAD/CAM fabricated zirconia crowns demonstrated a better accuracy of fit when compared to metal-ceramic crowns fabricated by conventional technology. Key words:Marginal fit, Internal fit, Computer-aided design/computer-aided manufacturing (CAD/CAM).

Marginal and internal fit evaluation of conventional metal-ceramic versus zirconia CAD/CAM crowns

BackgroundThe purpose of this in vivo study was to compare the marginal and internal gap widths of monolithic zirconia crowns fabricated by CAD/CAM technique and metal-ceramic crowns fabricated by conventional technique. Material and Methods10 participants needing a single restoration were selected. Zirconia crowns using CAD/CAM technology (Group A) (n=10) and metal-ceramic crowns (Group B) (n=10) using lost wax casting technique were fabricated for each selected tooth. The marginal and internal gaps of crowns were recorded using a replica technique with light body silicone material stabilized with a regular set putty. Each replica was sectioned buccolingually and mesiodistally and then evaluated at five pre-determined sites. The points measured were PM for marginal gap, PA for axial gap, PAO for axio-occlusal transition gap and PO and PCO for occlusal gaps using a stereomicroscope at 30× magnification. The Paired Sample (t) test was used to detect significant differences between the two groups in terms of marginal and internal fit (α= 0.05). ResultsThe mean for the marginal gap was 77.42μm (±39.5μm) for Group A compared with 95.86μm (±55.12μm) for Group B. Mean values for internal gap was 87.24 (±21.7 µm) for Group A and 132.91 µm (± 50.63 µm) for Group B. Significant differences were observed between both the groups for marginal (p=.010) and internal (p=.000) fit. ConclusionsThe CAD/CAM fabricated zirconia crowns demonstrated a better accuracy of fit when compared to metal-ceramic crowns fabricated by conventional technology. Key words:Marginal fit, Internal fit, Computer-aided design/computer-aided manufacturing (CAD/CAM).