The technologies for full dentures realization are almost the same for more than fifty years despite their being associated with many risks of error. In recent years, digital technologies have been ...increasingly used in dental practice, due to the many advantages it offers. The CAD / CAM technologies, are moving constantly in new directions, to provide exciting, innovative products and systems, with the highest quality standards. Thanks to CAD/CAM technologies, perfect clinical restorations can be achieved, with no secondary reactions and excellent esthetic appearance, through a digital cooperation between dentists and dental laboratories. CAD/CAM technology allows the realization of a well-fitting, aesthetic, and durable prosthetic appliances. Conventional technologies also have a number of advantages and disadvantages that must be known, and computerized methods have not only advantages but also disadvantages. We cannot notice that there is an ideal technology, but that we can choose, knowingly, the most appropriate method for each clinical case. The present paper aims to comparatively analyze a series of clinical parameters of conventional complete and CAD-CAM complete dentures.
The paper presents investigations of different copper microchannel structure manufacturing technologies. Both additive and subtractive techniques are taken into consideration. Performed tests show ...that due to the chosen material and dimensions only wire cutting process and milling process can be selected. The use of these methods results in differences in obtained microchannel shape. Further, the analysis of microchannel shape, various geometrical and thermal parameters and their influence on cooling abilities of the microchannel structures are presented. It is shown that the geometry resulting from chosen manufacturing technology may impact the overall thermal performance of the copper microstructures, especially for heat transfer coefficients below 5
W/cm
2
K. The numerical analysis has been conducted with the aid of ANSYS software.
To evaluate the trueness, precision, time efficiency, and cost of three different workflows for manufacturing single crowns (SCs).
A plaster model with a prepared tooth (#15) was scanned with an ...industrial scanner, and an SC was designed in computer-assisted-design (CAD) software. Ten SCs were printed with a hybrid composite (additive chairside) and a stereolithographic (SLA) printer (Dfab®), 10 SCs were milled in lithium disilicate (subtractive chairside) using a chairside milling unit (inLab MC XL®), and 10 SCs were milled in zirconia (lab-based) using a five-axis laboratory machine (DWX-52D®). All SCs were scanned with the same scanner after polymerization/sinterization. Each scan was superimposed to the marginal area of the original CAD file to evaluate trueness: absolute average (ABS AVG), root mean square (RMS), and (90˚-10˚)/2 percentile were calculated for each group. Marginal adaptation and quality of the occlusal and interproximal contact points were also investigated by two prosthodontists on 3D printed and plaster models. Finally, the three workflows' time efficiency and costs were evaluated.
Additive chairside and subtractive lab-based SCs had significantly better marginal trueness than subtractive chairside SCs in all three parameters (ABS AVG, p < 0.01; RMS, p < 0.01; 90˚-10˚/2, p < 0.01). However, the two prosthodontists found no significant differences between the three manufacturing procedures in the quality of the marginal closure (p = 0.186), interproximal (p = 0.319), and occlusal contacts (p = 0.218). Both time efficiency and cost show a trend favoring the chairside additive workflow.
Chairside additive technology seems to represent a valid alternative for manufacturing definitive SCs, given the high marginal trueness, precision, workflow efficiency and low costs.
Additive chairside manufacturing of definitive hybrid composite SCs is now possible and shows high accuracy, time efficiency, and competitive cost.
To compare and analyze trueness and precision of provisional crowns made using stereolithography apparatus and subtractive technology.
Digital impressions were made using a master model and an ...intraoral scanner and the crowns were designed with CAD software; in total, 22 crowns were produced. After superimposing CAD design data and scan data using a 3D program, quantitative and qualitative data were obtained for analysis of trueness and precision. Statistical analysis was performed using normality test combined with Levene test for equal variance analysis and independent sample t-test. Type 1 error was set at 0.05.
Trueness for the outer and inner surfaces of the SLA crown (SLAC) were 49.6±9.3 µm and 22.5±5.1 µm, respectively, and those of the subtractive crown (SUBC) were 31.8±7.5 µm and 14.6±1.2 µm, respectively. Precision values for the outer and inner surfaces of the SLAC were 18.7±6.2 µm and 26.9±8.5 µm, and those of the SUBC were 25.4±3.1 µm and 13.8±0.6 µm, respectively. Trueness values for the outer and inner surfaces of the SLAC and SUBC showed statistically significant differences (
<.001). Precision for the inner surface showed significance (
<.03), whereas that for the outer surface showed no significance (
<.58).
The study demonstrates that provisional crowns produced by subtractive technology are superior to crowns fabricated by stereolithography in terms of accuracy.
Embroidery is often the preferred technology when rigid circuit boards need to be connected to sensors and electrodes by data transmission lines and integrated into textiles. Moreover, conventional ...circuit boards, like Lilypad Arduino, commonly lack softness and flexibility. One approach to overcome this drawback can be flexible sequins as a substrate carrier for circuit boards. In this paper, such an approach of the development of flexible and functional sequins and circuit boards for wearable textile applications using subtractive and additive technology is demonstrated. Applying these techniques, one-sided sequins and circuit boards are produced using wax printing and etching copper-clad foils, as well as using dual 3D printing of conventional isolating and electrically conductive materials. The resulting flexible and functional sequins are equipped with surface mounted devices, applied to textiles by an automated embroidery process and contacted with a conductive embroidery thread.
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