The purpose of this study was to attempt to apply the magnetic attachment (Magfit^TMEX 400 W) as retainers for denture type spacemaintainers and orthodontic appliances in pediatric dentistry.
We studied the effect on the retention force of magnet dentures according to the direction of traction, number of anchor teeth, kinds of teeth for the anchor and the angle of the keeper to the anchor teeth using the dental study model of the mixed dentition. These data were statistically analyzed using ANOVA and subsequently Fisher's PLSD.
We moreover compared the retention force of the denture with Adamus clasps with magnetic attachments in the clinical cases. These data were statistically analyzed using the student's t-test. The results were as follows.
1)The optimum angle of the attached keeper to the tooth axis was 10°in the maxillary first and second desiduous molar and the maxillary first molar, when the retention force of the denture type appliance with a different keeper angle,0°,10°and 20° was investigated.
2) As the number of anchor teeth increased from two to four, the retentive force was increased. The comparatinely high retention force when first deciduous molar was included as an anchor tooth was also observed.
3) Concerning the relationship between retentive force and the tractive direction of denture type appliance, it tended to show a high retentive force when the anchor teeth were located near the tractive direction.
4) The retentive force of the appliance with magnetic attachment was 1.5 fold higher than that of with Adamus clasp in the clinacal cases. In all of the clinical cases, the retentive force of the appliance with magnetic attachments also showed a higher retention force than that with the Adamus clasps.
These findings suggested that the magnetic attachments can be useful as retainers for denture type appliances in pediatric dentistry.