Primary stability of orthodontic mini-implants inserted into maxilla and mandible of swine.
OBJECTIVE
The objective of this study was to assess the primary stability of different orthodontic mini-implants inserted into different maxillary and mandibular regions of swine.


METHODS
One hundred eighty orthodontic mini-implants produced by 5 different manufacturers, all presenting several shapes, were divided into 5 groups: Mondeal (M), Neodent (N), SIN (S), INP, and Titanium Fix (T). Fifteen pigs (Sus scrofa piau) were used for study and 12 mini-implants were inserted into 3 mandibular and maxillary regions. After insertion, the animals were killed and osseous blocks containing the mini-implants were obtained for mechanical pullout tests to be performed by a universal test machine at cross-head speed of 0.5 mm/s. Maximum force values (N/cm) for insertion were recorded and submitted to both analysis of variance and Tukey's test.


RESULTS
The primary stability provided by cylindrical mini-implants (groups M and I) was statistically significantly superior to that of conical mini-implants (groups N and S). On the other hand, screw-type mini-implants were shown to be statistically inferior compared with the others (P < .05). Statistical differences between pullout forces at different oral cavity regions were also found (P < .05). The mini-implants inserted into palatal suture had lesser stability, whereas those inserted into upper molar and premolar regions were shown to be more stable.


CONCLUSIONS
The shape of mini-implants, in association with location of insertion, is directly related to primary stability.
Southwest Bahia University, UESB, Bahia, Brazil. matheuspithon@bol.com.br
Matheus Melo
MM
Pithon
Matilde Gonçalves
MG
Nojima
Lincoln Issamu
LI
Nojima
D000818:Animals; D015519:Bone Density; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D003799:Dental Stress Analysis; D020878:Device Removal; D008297:Male; D008334:Mandible / Q000601:surgery; D008437:Maxilla / Q000601:surgery; D008904:Miniaturization; D016348:Osseointegration; D034421:Sus scrofa
D015921:Dental Implants