Wax Pattern Research Articles

High Efficiency Producing Technology Applied in Metal Optical Lens by 3D Wax Printing Combined with Investment Casting

3D printing technology can easily and quickly produce small batch models and full-size parts, which has obvious and important benefits in shortening development time. Since metals exhibit excellent mechanical strength and high wear resistance, metal additive manufacturing (MAM) is a popular technology for making metal parts. However, metal powders and 3D-printing machines are costly, which increases the difficulty of achieving mass production through MAM. In this study, the 3D wax printing and investment casting (WPIC) approach was developed to manufacture high-quality metal optical lenses with high efficiency and low cost. The manufactured lenses had a diameter of 38.1 mm, two radii of curvature (15 and 90 mm), and a cooling channel. These lenses were manufactured through 3D printing by using wax patterns produced through investment casting. The manufacturing efficiency and machining accuracy of the lenses produced using the proposed method were compared with those of lenses produced through MAM and investment casting. The results indicated that the total costs of manufacturing an optical lens through MAM and investment casting were nine and eight times greater, respectively than that of manufacturing an optical lens through WPIC. In addition, the surface roughness of metal lenses manufactured through WPIC was 45% lower than that of lenses manufactured through MAM. Finally, the time required to manufacture 50 metal lenses was only 15 days when WPIC was used; the corresponding time was 25 days and 6 months when MAM and investment casting were used, respectively. According to the above-mentioned results, the WPIC process has excellent advantages in product manufacturing cost and developing schedule over MAM and traditional methods of investment casting.

Influence of Silver Nanoparticle Integration on the Composition and Surface Properties of Acrylic Dental Resins Employed in Temporary Bridges

Background: Recognized widely for its irreversible effects, periodontal disease stands as one of the most prevalent conditions, particularly emphasizing the potential for permanent damage caused by gingivitis, extending to encompass the entirety of the supportive complex, including the connective tissue and alveolar bone. Patients necessitating comprehensive periodontal and prosthetic treatments require an interdisciplinary approach, involving the coordination of pre-treatment procedures and appropriate prosthetic strategies. The adoption of advanced materials and techniques can prove beneficial in addressing complex dental issues. (2) Methods: Forty specimens were prepared using the prescribed procedure, with 20 acting as controls and the other 20 integrating AgNPs. The initial step involved crafting wax patterns of distinct shapes: dumbbell shapes for tensile testing and rectangular shapes for roughness assessments. These dimensions were aligned with ASTM D-638 and ISO 527-2 standards and adjusted to match the specifications of the analysis device for mechanical properties. (3) Results: In this case, the results indicate minimal differences in heat-curing acrylic resins compared to the control samples at a 5% concentration. However, notable disparities arise at concentrations of 10% and 20%. (4) Conclusions: Temporary prosthetic constructions are essential for preventing functional imbalances and complications. Incorporating AgNPs at a 5% concentration maintains mechanical properties while providing antibacterial effects for long-term interim prosthodontic restorations. Higher nanoparticle concentrations may reduce resin mechanical properties without affecting material surface condition

Comparison of the Marginal and Internal Fit of Ceramic Laminate Veneers Fabricated with Four Different Computer-Aided Manufacturing Techniques.

Purpose: The improvement of computer-aided design and computer-aided manufacturing (CAD/CAM) has changed the methods of fabricating laminate veneers. The objectives of this study were to evaluate the marginal and internal fit of ceramic veneers manufactured with different CAD/CAM techniques. Materials and methods: A metal die was made by copying a prepared plastic maxillary central right incisor and scanned for designing a laminate veneer. One hundred laminate veneers were made with four different CAD/CAM techniques (n=25), including milled lithium disilicate (MLD), heat-pressed lithium disilicate with 3-dimensional (3D) printed wax patterns (PLD), milled zirconia (MZ), and 3Dprinted zirconia (PZ). The virtual marginal and internal fit of fabricated veneers was evaluated with digital crown fitting software. The actual marginal and internal fit was measured with the silicone replica method under a digital microscope. The measured data were analyzed using the one-way analysis of variance and the Turkey test. Results: There were significant differences in marginal and internal fit (P < 0.001) among manufacturing techniques. Both the virtual and actual marginal and internal gaps were higher in the PLD and PZ groups compared to the MLD and MZ groups. Conclusion: All four CAD/CAM techniques of manufacturing veneers, that is, milled lithium disilicate, heat-pressed lithium disilicate with 3D-printed wax patterns, milled zirconia, and 3D-printed zirconia, have clinically acceptable marginal and internal fit. Milled zirconia and lithium disilicate veneers demonstrated superior marginal and internal fit compared to 3D-printed zirconia and heat-pressed lithium disilicate veneers with 3D-printed wax patterns.

Wax Patterns, Textural Properties, and Quality Attributes of Two Eggplant (Solanum melongena L.) Cultivars during Storage

Two eggplant cultivars (Brigitte and Dalong) were stored under ambient conditions for 8 days to examine the postharvest quality and shelf life. Results indicated that the respiration rate, firmness and springiness, and nutritional quality of both eggplant cultivars decreased with the extension of shelf life. On the contrary, opposite trends were observed in weight loss, gumminess, and chewiness of eggplant fruits. In addition, the weight loss of ‘Brigitte’ eggplant fruits was 3.3% and 6.9% lower compared with ‘Dalong’ eggplant fruits at 4 and 8 days after storage. Thicknesses of epidermal cells and the stratum corneum, the epicuticular wax content of ‘Brigitte eggplant fruits increased by 42.9%, 766.7%, and 58.8% compared with ‘Dalong’ eggplant fruits, respectively, with a concomitant increase in the dense wax layer structure. In conclusion, the storage tolerance of ‘Brigitte’ eggplant fruits was higher than that of ‘Dalong’ eggplant fruits due to the higher epicuticular wax content and dense wax layer structure.

Effect of Composition and Pouring Temperature of Cu-Sn on Fluidity and Mechanical Properties of Investment Casting

The composition and pouring temperature are important parameters in metal casting. Many cast product failures are caused by ignorance of the influence of both. This research aims to determine the effect of adding tin composition and pouring temperature on fluidity, microstructure and mechanical properties including tensile strength and hardness of tin bronze (Cu-Sn). The Cu-Sn is widely used as employed in the research is Cu (20, 22 and 24) wt.%Sn alloy using the investment casting method. Variations in pouring temperature treatment TS1 = 1000°C and TS2 = 1100°C. The mold for the fluidity test is made with a wax pattern then coated in clay. The mold dimensions are 400 mm long with mold cavity variations of 1.5, 2, 3, 4, 5 mm. Several parameters: increasing the pouring temperature, adding tin composition, decreasing the temperature gradient between the molten metal and the mold walls result in a decrease in the solidification rate which can increase fluidity. The α + δ phase transition to β and γ intermetallic phases decreases fluidity at &amp;gt;22wt.%Sn. The columnar dendrite microstructure increases with the addition of tin composition and pouring temperature. The mechanical properties of tensile strength decrease, hardness increases and the alloy becomes more brittle with increasing tin composition.

Fabrication of sacrificial wax pattern through large-scale fused granulated fabrication (FGF-AM) hybrid manufacturing system

Fabrication of sacrificial wax pattern through large-scale fused granulated fabrication (FGF-AM) hybrid manufacturing system

Effect of pattern fabrication methods on retentive strength in three‐unit implant‐supported frameworks: A comparative analysis

AbstractObjectiveGiven the significant role of retention in the long‐term success of implant‐supported prostheses, this study aimed to compare the retentive strength of three‐unit implant‐supported frameworks manufactured using the conventional, subtractive milling, and 3D printing methods.Materials and MethodsIn this in vitro study, two fixture analogs were placed in the mandibular right first premolar and first molar region of a Dentiform model, and two prefabricated abutments were secured in the fixture analogs. A total of 27 three‐unit frameworks were fabricated utilizing wax patterns prepared through conventional, milling, and 3D printing techniques (n = 9 per group). The frameworks were cemented with zinc oxide eugenol and subjected to thermocycling. The retentive strength of each specimen was evaluated through a pull‐out test conducted with a universal testing machine. The data were analysed using one‐way ANOVA and Tukey's post hoc test (p &lt; 0.05).ResultsThe three groups were found to be significantly different (p = 0.01). While the 3D printing and milling groups were not significantly different (p = 0.99), they yielded significantly higher retentive strength compare to the conventional group (p = 0.02 for 3D printing and p = 0.03 for milling group).ConclusionThe utilization of 3D printing and milling technique for wax pattern preparation significantly increased the retention of the implant‐supported framework, with no statistically significant difference between the two methods.

An innovative approach for lid design for rehabilitation of maxillary oncological defect using hollow bulb obturator

BackgroundPost Maxillectomy, prosthodontic treatment modalities include surgical obturator, interim obturator and followed by definitive obturator. The surgical and interim obturator serves the purpose of providing a matrix on which surgical packing can be placed, reduces the contamination during wound healing, facilitates speech and permits deglutition and lessens the psychological impact of surgery. Local drug delivery techniques at the surgical site and the fabricated prosthesis have an impact on the targeted tissue. ObjectivesTo design a hollow bulb obturator with a detachable lid with attachments in the palatal surface of the obturator and to facilitate local drug delivery. MethodsDuplication of patient's maxillectomy cast, pre-shaped plaster bolus was incorporated inside the defect space to create the hollow space. After which a wax pattern was fabricated and acrylized. Wax template of the lid design was made and acrylized incorporating pins. ResultThe weight of the prosthesis is reduced. Due to the lesser weight of the prosthesis retention and physiologic function increases. The decrease in pressure to the surrounding tissue aids in deglutition and encourages the regeneration of tissue. The fabricated lid appears stable and retentive, which can be easily removed and placed back according to the need. ConclusionLocal drug delivery techniques at the surgical site and the fabricated prosthesis has an impact on the targeted tissue.The ability of the drug to reach the appropriate anatomic region will always be important, and has been the subject of much research in the past 5 years. Modified hollow bulb of the obturator in this research can aid in local drug delivery in surgical and interim obturators avoiding the removal of the obturator as the whole.

Comparing the trueness of 3D printing and conventional casting for the fabrication of removable partial denture metal frameworks for patients with different palatal vault depths: An in vitro study

Statement of problemThe success of a removable partial denture depends on its fit, and, with conventional casting, the framework is more distorted in patients with a deep palatal vault. Questions remain about whether the three-dimensional (3D) printing technique for fabricating a framework can improve the accuracy of fit for these patients. PurposeThe purpose of this in vitro study was to compare the trueness of metal frameworks fabricated by selective laser melting, 3D printing pattern casting, and conventional casting for different palatal vault depths. Material and methodsA total of 30 partially edentulous maxillary casts were custom-made in 15 medium and 15 deep palatal vaults. All stone casts were scanned as reference models in digital files. For the medium palatal vault casts, Co-Cr frameworks of the conventional casting (CON) group (n=5) were fabricated with the lost wax technique. For the 3D printing pattern casting (PPC) group (n=5), wax patterns of the framework were printed, followed by metal casting. The frameworks created for the selective laser melting (SLM) group (n=5) were printed directly by using the SLM machine. The same procedures were followed for the deep palatal vault group. All the metal frameworks were scanned and superimposed with the reference casts by using the Geomagic Control X software program. Discrepancies were measured as mean ±standard deviation (trueness), and the data were statistically analyzed with a 2-way ANOVA test to evaluate the interaction of 2 independent factors (fabrication techniques and palatal vault depths) on a trueness outcome (α=.05). ResultsThe lowest mean ±standard deviation value was 0.092 ±0.023 mm, found from the SLM framework with deep palatal vault group, while the highest value was 0.194 ±0.017 mm, found from the CON framework with deep palatal vault group. Different fabrication techniques interacted with different palatal vault depths in terms of trueness (P<.05); however, no significant differences were observed in the medium palatal vault groups (P>.05). Additionally, color mapping demonstrated the gaps of metal frameworks among the 6 groups. ConclusionsWith the conventional casting technique, the accuracy of the metal framework was affected by the depth of the palate. For medium palatal vaults, all fabricated frameworks had clinically acceptable fit. For deep palatal vaults, the SLM frameworks showed the lowest discrepancy. As a result, the SLM technique is advised for fabricating a better-fitting metal framework for patients with a deep palatal vault.

A multi-objective optimization based on machine learning for dimension precision of wax pattern in turbine blade manufacturing

A multi-objective optimization based on machine learning for dimension precision of wax pattern in turbine blade manufacturing

A novel method for evaluating thermal expansion forces during dewaxing of investment casting and 3D-printing waxes

This study proposes a novel method for the evaluation of expansion forces that occur during the heating of IC (investment casting) waxes with the help of a rheometer. Thermal expansion of the IC wax patterns is the main reason that causes ceramic shell failure during the dewaxing process. The technique is based on the measurement of normal forces that develop in the measuring system of the rotational rheometer during solidification of wax samples. These forces are created as a result of shrinkage of thermally expanded wax samples. To assess the efficiency of the proposed method, three types of commercially available waxes and one 3D-printable wax have been tested and compared. According to research findings, the proposed method can be prescribed as an efficient procedure for the evaluation of expansion forces that develop during wax heating, especially for waxes that have low viscosity properties. It was observed that machinable wax produced the highest value of normal load equivalent to 86 N while the IC and 3D-printing wax generated 18.8 and 36.3 N respectively. Moreover, it was discovered that additively manufactured wax patterns perform considerably better compared to their casted analogs during dewaxing processes

Evaluation of the trueness and precision of ceramic laminate veneers fabricated with four computer-aided manufacturing methods

The accuracy of computer-aided design/computer-aided manufacturing (CAD/CAM) methods plays an important role in the clinical success of ceramic veneers. This study aimed to evaluate the impact of different CAD/CAM methods, including subtractive, hybrid, and additive manufacturing, on the trueness and precision of ceramic veneers. A typodont central incisor was prepared for a laminate veneer, followed by the design of a veneer with CAD software. Ceramic veneers were fabricated with four different CAD/CAM methods, including milled lithium disilicate, pressed lithium disilicate with three-dimensional (3D) printed wax patterns, milled zirconia, and 3D-printed zirconia. All veneers were scanned and imported to 3D inspection software for trueness and precision evaluation. Laminate veneers fabricated with all investigated methods exhibited clinically acceptable trueness and precision. Pressed lithium disilicate veneers from 3D-printed wax patterns and 3D-printed zirconia veneers showed lower precision of the fitting surfaces compared to their milled counterparts.

Marginal fit of 3-unit implant-supported fixed partial dentures: Influence of pattern fabrication method and repeated porcelain firings.

Marginal fit significantly impacts the long-term success of dental restorations. Different pattern fabrication methods, including hand-waxing, milling, or 3D printing, may affect restorations accuracy. The effect of porcelain firing cycles on the marginal fit of metal-ceramic restorations remains controversial, with conflicting findings across studies. The aim was to evaluate the potential effects of multiple porcelain firings (3, 5, 7 cycles) as well as pattern fabrication method (conventional hand-waxing, milling, and 3D printing) on the marginal adaptation of 3-unit implant-supported metal-ceramic fixed partial dentures. It was hypothesized that neither the wax pattern fabrication method nor repeated ceramic firings would significantly affect the marginal adaptation of metal-ceramic crowns. In this in-vitro study, 30 Cobalt-Chromium alloy frameworks were fabricated based on pattern made through three techniques: conventional hand-waxing, CAD-CAM milling, and CAD-CAM 3D printing (n = 10 per group). Sixteen locations were marked on each abutment to measure the vertical marginal gap at four stages: before porcelain veneering and after 3, 5, and 7 firing cycles. The vertical marginal gap was measured using direct microscopic technique at ×80 magnification. Mean vertical marginal gap values were calculated and two-way ANOVA and Tukey's post hoc tests were used for inter-group comparisons (α = 0.05). The 3D printing group showed significantly lower (P<0.001) mean vertical marginal gaps (60-76 μm) compared to the milling (77-115 μm) and conventional hand-waxing (102-110 μm) groups. The milling group exhibited a significant vertical gap increase after 3 firing cycles (P<0.001); while the conventional (P = 0.429) and 3D printing groups (P = 0.501) showed no significant changes after 7 firing cycles. Notably, the vertical marginal gap in all groups remained below the clinically acceptable threshold of 120 μm. CAD-CAM 3D printing provided superior marginal fit compared to CAD-CAM milling and conventional hand-wax pattern fabrication methods. The impact of porcelain firing on the mean marginal gap was significant only in the milling group. All three fabrication techniques yielded clinically acceptable vertical marginal adaptation after repeated firings. Additive manufacturing holds promise to produce precise implant-supported prostheses.

Role of silicon carbide in enhancing microwave hybrid heating and reducing dewaxing time in investment casting

Mould cracking is a common problem in investment casting (IC) that occurs during the dewaxing process, which is caused by the difference in thermal expansion between the wax pattern and the ceramic mould. Therefore, appropriate modifications to the mould, waxes and hybrid heating of the materials are proposed to address this problem. This study aims to investigate the effects of silicon carbide (SiC) addition on dewaxing time and mould structural defect in two different waxes (HYFILL B289 MOD S and SIVUCH L1203) under microwave hybrid heating. For the mould fabrication, stucco (Al2O3-SiO3) was added with various amounts of SiC to improve microwave heat absorption capabilities. The modified stucco was applied on layers 3–6 to ensure that the mould was more durable and suited for the casting process. The thermal expansion of the waxes and the ceramic mould was evaluated to determine its thermal expansion mismatch. The density, porosity, thermal conductivity, and dielectric properties were characterized to evaluate the properties of modified green mould. The results showed that SIVUCH L1203 wax outperformed HYFILL B289 MOD S wax, in obtaining a crack-free ceramic investment mould with a clean internal surface. This superiority is attributed to the exceptional thermal and absorption properties of the SIVUCH L1203 wax. Furthermore, the incorporation of SiC played a pivotal role in enhancing the hybrid heating process while maintaining the density and porosity of the green moulds. This was evident by the remarkable reduction of dewaxing time by 62% with 7.5% of SiC addition, which also contributed toward improving energy savings and sustainability.

Technological considerations regarding the use of CAD-CAM systems in the metal substructure design of some metal-ceramic prosthetic restoration

Abstract In this material, two clinical cases are described, regarding the use of CAD-CAM technology for producing the wax pattern of the metal substructure for a fixed prosthetic restoration. In fact, in these cases, it is about making a digital design and milling from a block of wax the patterns of future fixed metal-ceramic prosthetic restorations.

Enhancing the Cooling Efficiency of Aluminum-Filled Epoxy Resin Rapid Tool by Changing Inner Surface Roughness of Cooling Channels.

In low-pressure wax injection molding, cooling time refers to the period during which the molten plastic inside the mold solidifies and cools down to a temperature where it can be safely ejected without deformation. However, cooling efficiency for the mass production of injection-molded wax patterns is crucial. This work aims to investigate the impact of varying surface roughness on the inner walls of the cooling channel on the cooling efficiency of an aluminum-filled epoxy resin rapid tool. It was found that the cooling time for the injection-molded products can be determined by the surface roughness according to the proposed prediction equation. Employing fiber laser processing on high-speed steel rods allows for the creation of microstructures with different surface roughness levels. Results demonstrate a clear link between the surface roughness of cooling channel walls and cooling time for molded wax patterns. Employing an aluminum-filled epoxy resin rapid tool with a surface roughness of 4.9 µm for low-pressure wax injection molding can save time, with a cooling efficiency improvement of approximately 34%. Utilizing an aluminum-filled epoxy resin rapid tool with a surface roughness of 4.9 µm on the inner walls of the cooling channel can save the cooling time by up to approximately 60%. These findings underscore the significant role of cooling channel surface roughness in optimizing injection molding processes for enhanced efficiency.

Rapid Investment Casting: Towards Rapid Die Development

Abstract: Presently the cost of investment casting via wax patterns is an expensive endeavor. Its costs are only justified if the end product is to be produced in high volumes, however for customized products or small Industries, the costs are not viable. In Pakistan, die manufacturing is especially costly due to the use of modern computerized machines like CNC machining and electric discharge machining (EDM). The cost of manufacturing increases significantly with the complexity of the die, the number of cavities, high surface quality requirements, and the number of undercuts. The purpose of this research is to use modern techniques to investigate the feasibility of dies manufacturing through rapid investment casting technique. 3D printing technology is used to make the patterns for casting of die. The research focuses on the differences in dimensions between the actual casted die, and the designed values.

Revolutionizing Papertronics: Advanced Green, Tunable, and Flexible Components and Circuits

AbstractPapertronics introduce a sustainable, cost‐effective revolution in electronics, especially for the Internet of Things. This research overcomes the traditional challenges of paper's porosity, which has impeded electronic component fabrication and performance. A novel approach that harnesses paper's natural capillary action, combined with hydrophobic wax patterning, to achieve precise vertical integration of electronic components is introduced. This method marks a significant departure from conventional surface deposition techniques. This study demonstrates the successful creation of tunable resistors, capacitors, and field‐effect transistors, embedded within a single sheet of paper. Contrary to previous assumptions that impeded the use of paper, its rough and porous texture as a strategic advantage, facilitating the precise fabrication of intricate electronic components is leveraged. Machine learning algorithms play an important role in predicting and enhancing the performance of these papertronic components. This innovation facilitates the development of compact printed circuit boards with increased circuit density, enabling the integration of diverse analog and digital circuits in either single or multi‐layer paper formats. The resulting papertronic systems exceed performance benchmarks, offering eco‐friendly disposal through biodegradability or incineration. These breakthroughs establish papertronics as a feasible, eco‐friendly alternative in the electronics industry, permitting widespread adoption and continuous innovation in sustainable electronic solutions.

A Lab-Based Study to Assess the Surface Roughness of Various Investments: An Original Research.

Surface roughness of the crowns is dependent on the pattern material used for the making as well as the procedure of investing. The study was aimed to examine the impact of various pattern materials and investment procedures on the surface roughness of nickel-chromium alloy raw castings. An in-vitro study was piloted at a tertiary care hospital. Eighty samples of inlay wax and pattern resin were divided equally. They were invested in phosphate-bonded investment material and kept under normal atmospheric pressure as well as invested under a pressure of 3 bars. The surface roughness was calculated with a Profilometer. The values obtained were compared using statistical tools keeping P < 0.05 as significant. Lowest surface roughness was seen for the wax pattern invested under positive pressure. While the highest was seen for the resin patterns invested at room pressure. A significant variance between the wax 1 and wax 2 (P < 0.01); as well as between the wax 2 vs. Resin 2 specimens (P < 0.01) was noted. Wax patterns can be suggested as the material and method of choice because they showed the least amount of surface roughness when placed under pressure. Resin patterns when invested under pressure can also be suggested as an alternate as they also exhibited similar surface roughness as that of the wax.

The effect of glycerin-painted wax pattern on surface quality of dental stone mold

Aim: The aim of this study was to examine the effects of glycerin-coated wax patternon dental stone surface quality in terms of surface roughness and micro airbubble formation.Method: In this study, a total of 20 modeling wax samples were used for thehydrophilicity test (the contact angle test) divided into 2 groups (control andglycerin-painted). A total of 20 dental stone samples were also prepared forvisual and microscopic analysis divided into 2 groups (control and glycerinpainted).Results and conclusion: The contact angle data showed a significant decrease insurface hydrophilicity for the glycerin-painted group (P-value &lt; 0.05). However,the visual and microscopical analysis did not show a prominent distinction insurface quality between the two groups, so there is no noticeable effect on dentalstone surface caused by glycerin-modified wax pattern.