The Effect of Various Restorative Materials on the Microhardness of Reparative Dentin

This study showed a statistically significant difference between the microhardness of reparative and primary dentin at both five- and eight-week intervals. Reparative dentin from occlusal trauma is harder than reparative dentin underlying a cavity preparation at the 99% level. No statistical difference was noted in the hardness of reparative dentin underlying different materials, but trends were observed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66484/2/10.1177_00220345800590020101.pd

Reasons for placement and replacement of restorations in student clinics in Manchester and Athens

Data on reasons for the placement and replacement of restorations provide insight into patterns of clinical practice. This study investigated reasons for the provision of restorations in student clinics at the Universities of Manchester and Athens. Using the methods first described by Mjör, data were collected in relation to all initial and replacement restorations placed in adult patients in the main teaching clinics in the 2 schools over a 3-month period. The principal reason for intervention was recorded, according to approved treatment plans. Data were collected on 2620 restorations, 1431 (55%) of which were placed in Manchester. Primary caries was the main reason for the placement of initial restorations: 82% in Athens and 48% in Manchester (p<0.001). The principal reason for restoration replacement was secondary caries, accounting for 54% in Manchester and 33% in Athens (p<0.001). Other differences between the schools, included the ratio of initial placement to replacement restorations (Manchester 1:1.1; Athens 1:0.6: p<0.01) and significantly more 2-surface class II restorations having been placed in Manchester (p<0.001). Class III and IV restorations predominated in Athens. It is concluded, despite the acknowledged limitations of the methods employed, that the patterns of placement and replacement of restorations and the use of materials differ between the dental schools of Manchester and Athens. The differences are considered to relate more to local patterns of dental disease and patient selection for student clinics than to any differences in teaching philosophy. Subsequent studies of the type reported, despite acknowledged limitations would provide insight into the impact on patient care of the teaching of new materials, techniques and treatment philosophies. © Munksgaard, 2000