###### Abstract
The choice of the correct clasp geometry starts with the analysis of the Kennedy class and the insertion axis of the prosthesis, which determines the equator and the retentive zone of the tooth [12; 13]. A clasp assembly consists of an occlusal rest, a reciprocal arm and a retentive arm [12]. All claps must provide retention, stability, support, reciprocity and passivity and cover the largest possible area of the tooth [12; 15; 16]. The retentive arm provides primary retention of the prosthesis and must be able to deform as it passes the equator of the tooth and return to its original position without exerting damaging forces on the tooth [15; 17; 18]. In partial dedentulous patients with bilateral (Class I Kennedy) or unilateral (Class II Kennedy) distal extension, retention, stability and support are very important [19]. The selected clasp must provide good retention, transfer forces parallel to the tooth axis, and minimize the application of damaging forces to the abutment tooth [12; 19]. In these situations, it is common to use claps with mesial occlusal rests, such as the reverse back-action clasp when buccal retention is on the distal side and the back-action clasp when there is mesial retention [16; 19; 20]. Of the various materials available for the manufacture of the metal framework, cobalt-chromium (Co-Cr) alloy has been the most commonly used material since 1929 [21]. This material is known for its low cost and adequate mechanical properties, such as lower density and higher modulus of elasticity than gold, as well as its high corrosion resistance, which is related to biocompatibility [4; 17; 18; 21]. This metallic alloy contains about 53% to 67% Co, 25% to 32% Cr, 2% to 6% Mo, and a mixture of other elements [22; 23]. The lost waxing casting or conventional method is most commonly used to produce metal frameworks [9; 23]. The quality of the production largely depends on the experience of the laboratory technician and the quality of the impressions taken by the clinician, which is a time-consuming and expensive method [9; 24]. Normally, this technique is prone to several errors that can result in 75% of frameworks not fitting properly on the supporting structures at the time of insertion into the patient's oral cavity [12; 25; 26]. Thus, over the years, the need to develop new techniques has increased, and scientific advances have made it possible to improve the process of RPD framework production, reducing the time and cost of fabrication, and improving the fit and functional efficiency of rehabilitations [1; 3]. With the advent of digital technology, manufacturing methods have changed with the introduction of digital processes such as computer-aided design (CAD) and computer-aided manufacturing (CAM) [6; 27]. With the development of these new methods, the results have become more predictable, reproducible, and accurate, which improves the longevity of the rehabilitations [4; 28]. The use of CAD/CAM offers the advantages of digital planning and analysis, reduction in material waste and use of innovative materials, better communication between laboratory and clinician, reduction in the number of steps and errors, easy cast reproduction, and better quality control of the production [4; 29; 30; 31]. The production of these structures can be performed by two digital methods: addition (AM--additive manufacturing) or subtraction (milling) [29]. The AM method makes use of sintering technology, such as: SLM--Selective Laser Melting, SLS--Selective Laser Sintering or DMLS--Direct Metal Laser Sintering [9; 18]. This technology offers high productivity,improves the properties of materials by increasing density and homogeneity, and is a precise and cost-effective method [4; 9]. Basically, additive manufacturing is based on the production of metal objects in 3D by sintering metal powders with a high-power laser [9; 32]. In DMLS, a powder consisting of several metals is partially fused with a high-power Yb fiber laser [18; 32].