NEET MDS Shorts
953889
Conservative DentistryExplanation: The outline form of a Class V cavity preparation
is primarily determined by the extent of carious tissue. The goal is to remove
all carious dentin while preserving as much healthy tooth structure as possible.
The outline form must encompass the entire area affected by caries to ensure
that the restoration is effective and durable. Other factors, such as the height
of the gingival crest, type of restorative material, and tooth anatomy, may
influence the preparation but are secondary to the extent of caries.
571737
Conservative DentistryExplanation:Sodium nitrite is often used as a protective agent during the autoclaving process to prevent corrosion of dental instruments, including burs. It helps to maintain the integrity of the metal during the sterilization process.
744262
Conservative DentistryExplanation: When dealing with adjacent Class III cavities, it is generally recommended to prepare the larger cavity first and fill it last. This approach allows the dentist to have better access and visibility when preparing the larger cavity, which can be more complex. Filling the larger cavity last helps to avoid contamination and ensures that the smaller cavity can be filled with precision without compromising the integrity of the larger restoration.
785586
Conservative DentistryExplanation: The external shape of a Class V amalgam
restoration is closely related to the contour of the marginal gingiva. This is
important for aesthetic and functional reasons, as the restoration must blend
seamlessly with the surrounding gingival tissue. The outline form should respect
the natural contours to minimize plaque accumulation and promote periodontal
health. While axial line angles and the direction of enamel rods are relevant to
the preparation, they do not primarily dictate the external shape of the
restoration.
308170
Conservative DentistryAnnealing gold foil is the process of heating gold to remove impurities and restore its cohesion properties. Annealing of gold foil is a heat treatment process used to alter the physical and sometimes chemical properties of the material. The primary purpose of annealing gold foil is to remove any contaminants and stresses that may be present on the surface of the material. This is achieved by heating the gold foil to a specific temperature, typically around 400°C (750°F), and then allowing it to cool slowly. The process can also help in improving the foil's ductility, making it more malleable and easier to work with. However, the direct effect of annealing on the rigidity, ductility, and proportional limit is not explicitly stated in the question, and thus the correct answer is that annealing of gold foil primarily serves to remove contaminants from the surface.
499027
Conservative DentistryExplanation: The lingual approach to the distal surface of a canine for Class III amalgam restoration is primarily related to aesthetics. This approach minimizes visibility of the restoration from the facial aspect, which is important for maintaining the natural appearance of the tooth. Aesthetic considerations are particularly significant in anterior teeth, where the visibility of restorations can impact the overall smile and facial aesthetics. While retention, outline form, and resistance are important factors in cavity preparation, the lingual approach is specifically chosen to enhance the aesthetic outcome.
402381
Conservative DentistryIn class V preparation, the pulpal wall is not present at all, as the cavity is
confined to the cervical third of the tooth. It does not extend into the pulp
chamber.
926802
Conservative DentistryEmery is a polishing agent that can be used to polish amalgam restorations. It is a natural abrasive material that is relatively safe for metal surfaces and does not cause significant wear on the amalgam. Garnet, silex, and alumina are also abrasive materials, but they are less commonly used for polishing amalgam due to potential issues with scratching or wearing down the restoration.