A.To remove infected dentine and prohibit caries B.To protect the pulp and avoid pain C.To enhance the strength of the tooth D.To facilitate plaque control E.To restore the appearance(of teeth)and its function 43 Which is the best statement about resistance form A.Resistance form is the design of a cavity in such a way that the remaining tooth substance and the restorative material can withstand masticatory stress B.The bulk required will depend on the flexural strength of restorative material.In the case of amalgam it is estimated that a minimum of 1.5-2mm thickness of the restorative material is required to withstand masticatory stress C.If a marginal ridge is found to be too weak in the cause of an occlusal cavity preparation,a Class II cavity may have to be prepared instead,so as to eliminate the weak marginal ridge.This is particularly indicated where the ridge is only of enamel thickness and unsupported by sound dentine D.The cavity should be designed that the occlusal margins of the cavity are in areas not subjected to excessive occlusal trauma,otherwise the enamel wall of the cavity and/or the margins of the restorative material may fracture.In practice,this may be achieved by placing an occlusal margins of a cavity about one-quarter (1/4)of the intercuspal distance.Note,that efforts should always be made to conserve sound tooth tissue E.All of the above 44 Which is the most danger area of tooth in dental caries occurred after you have learned dental caries? A.Pits and fissures on occlusal surfaces of molars and premolars B.Approximal surfaces of all teeth. C.Gingival thirds of all teeth,both on facial and lingual surfaces D.Pits and fissures near the lingual of maxillary incisors and canines (lingual pits) E.Pits and fissures on the buccal of molars 45 Which is not true in the following statement about dental caries and micro-organisms? A.Caries could be induced by specific bacteria,especially mutans streptococci-group (eg.Streptococcus mutans and Strep.sobrinus). B.There are caries occurred when only fed a cariogenic (high sucrose)diet. C.In the '60s Keyes infected germ-free animals with known strains of streptococci and found that these organisms were transferred to uninfected litter mates who then became susceptible to caries.He thus demonstrated that dental caries was potentially infectious and transmissible. D.When talking about cariogenic microorganisms,we often refer to Streptococcus mutans,Lactobacillus and Actinomyces. E.Occlusal caries could be prevented using penicillin in animal study.A. To remove infected dentine and prohibit caries B. To protect the pulp and avoid pain C. To enhance the strength of the tooth D. To facilitate plaque control E. To restore the appearance (of teeth) and its function 43 Which is the best statement about resistance form A. Resistance form is the design of a cavity in such a way that the remaining tooth substance and the restorative material can withstand masticatory stress B. The bulk required will depend on the flexural strength of restorative material. In the case of amalgam it is estimated that a minimum of 1.5-2mm thickness of the restorative material is required to withstand masticatory stress C. If a marginal ridge is found to be too weak in the cause of an occlusal cavity preparation, a Class II cavity may have to be prepared instead, so as to eliminate the weak marginal ridge. This is particularly indicated where the ridge is only of enamel thickness and unsupported by sound dentine D. The cavity should be designed that the occlusal margins of the cavity are in areas not subjected to excessive occlusal trauma, otherwise the enamel wall of the cavity and/or the margins of the restorative material may fracture. In practice, this may be achieved by placing an occlusal margins of a cavity about one -quarter (1/4) of the intercuspal distance. Note, that efforts should always be made to conserve sound tooth tissue E. All of the above 44 Which is the most danger area of tooth in dental caries occurred after you have learned dental caries? A. Pits and fissures on occlusal surfaces of molars and premolars B. Approximal surfaces of all teeth. C. Gingival thirds of all teeth, both on facial and lingual surfaces D. Pits and fissures near the lingual of maxillary incisors and canines (lingual pits) E. Pits and fissures on the buccal of molars 45 Which is not true in the following statement about dental caries and micro-organisms? A. Caries could be induced by specific bacteria, especially mutans streptococci-group (eg. Streptococcus mutans and Strep. sobrinus). B. There are caries occurred when only fed a cariogenic (high sucrose) diet. C. In the ’60s Keyes infected germ-free animals with known strains of streptococci and found that these organisms were transferred to uninfected litter mates who then became susceptible to caries. He thus demonstrated that dental caries was potentially infectious and transmissible. D. When talking about cariogenic microorganisms, we often refer to Streptococcus mutans, Lactobacillus and Actinomyces. E. Occlusal caries could be prevented using penicillin in animal study