## 4 Discussion
Providing dental laboratories impressions with adequate design information is critical, as the technician does not have access to crucial information relating to the nature and health (biology) of the periodontal and oral tissues. This will reflect negatively on the prosthesis fabrication accuracy and may result in damage and injuries to dental and periodontal tissues. In this present survey, about 7.7% of the dentists did select the components that were needed for cast removable partial dentures in their work authorizations, but some did not. Those who did not complete the design left it for the dental technician to decide by himself or herself. Since rests, clasps, and connectors are essential components in cast removable partial dentures in order to achieve retention, resistance, and support, their proper selection plays a vital role in the design process for every individual patient. A lack of proper connector designing can lead to impingement of the gingival margins and failure to provide relief at the gingival margins [23]. Moreover, an unfitting design of the clasps can lead to fracturing of the clasps and a lack of retention [22]. Furthermore, incorrect designing of the rests can result in undue stress on the RPD [23]. It is clear, however, that the dentists should select and decide upon the components of the RPD, such as guide planes, and communicate this to the dental technicians [24]. Since it is the dentist who has studied the anatomy of the teeth and occlusion of patients, including the physiological and pathological processes in the oral cavity, selecting the right components of the RPD for the patient is the responsibility of the dentist. Furthermore, the choice of denture material, including metal alloy, which is used for a removable partial denture, has its effect on the patient, dentist, and technician with respect to allergic reactions, cost, corrosion resistance, castability, and personal choice. The American Dental Association indicates that the type of metal alloy that is used has its ethical and legal implications on the dentist [25]. In our study, about 72.3% of the dentists did choose a specific material for the construction of RPDs, but 10.7% of the dentists did not. One study in the literature emphasized the choice of material for RPDs such as cobalt chromium, but aesthetics was a major concern [26]. The number and design of the pontics for fixed partial dentures is critical for the gingival health and ability to be cleaned by the patients. In the present study, most of the dentists selected the number and design of the pontics for the FPDs. However, previous reports from dental laboratories have suggested that some dentists fail to include the information about the number and design of the pontics for fixed partial dentures [27]. In this study, we found that about 67.7% of the dentists did select the type of margins for a fixed partial denture, but 17.2% of the dentists did not. The importance of the margin design has been emphasized in order to maintain oral hygiene and the periodontal health of the patient. Improper margin design of an FPD might lead to the creation of a favorable environment for the deposition of plaque, development of caries, and periodontal diseases [28]. In the present study, 64.9% of the dentists instructed the dental technicians about the surface of the FPDs to be covered with metal, but 17.1% of the dentists did not. Metal alloys are known to be vital for the construction of FPDs, as the presence of metal increases the -fracture resistance, leading to an increase in the life of the prosthesis [29]. Furthermore, the presence of metal alloys provides FPDs the strength to resist occlusal forces and durable occlusal contact [29]. In addition, the type of metal alloy selection in the construction of FPDs plays a vital role, as precious metals provide a much better fit at the margins and adaptation compared with base metals, along with the variable costs of the metals.