Abstract:

Objective　To evaluate thein vivoretentive forces of mandibular complete overdenture with Magfit attach- ments, as well as the relation between the location of magnetic attachments and the retentive forces of the denture.Methods　5 patients were selected and treated with mandibular complete overdentures retained by Magfit EX600 and MD800 attachments. A strainometerwas used to measure the retentive forces in anterior, central and posterior parts of the overdenture before and after magnets were set. The vertical and anterior-upper 60°retentive forces of the overdenture were measured one month later.Results　 The retentive forces of the overdentures after setting magnets were significantly greater than that before magnets were set (P< 0·05).There was no significant difference in retentive forces between the different parts (P>0·05). The retentive force in verti- cal direction was greater than that in anterior-upper 60°direction (P<0·025).Conclusion　Magnetic attachments can signifi- cantly improve the retention of mandibular complete overdenture. The location of magnetic attachments greatly influences the re- tentive force of the overdenture.

Key words: magnetic attachment, overdenture, retentive force