Influence of surface characteristics on survival rates of mini-implants.
OBJECTIVE
To compare the clinical performance and the survival rate of two mini-implant systems with different surface characteristics under immediate orthodontic loading.


METHODS
Seventeen machined titanium (MT) mini-implants and 15 sandblasted, large grit, acid-etched (SLA) mini-implants were placed in 10 patients. The mini-implants were immediately loaded and the patients seen at 7, 14, 30, 60, and 150 days. Clinical parameters such as anatomical location, character of the soft tissue at the screw head emergence, type of mini-implant system, diameter, and length were analyzed. In addition, the insertion torque recorded at the time of insertion was also assessed. Survival rate and clinical parameters were evaluated by the chi-square exact tests using the SAS version 9.1.


RESULTS
The overall survival rate was 87.5%. Over the four failing mini-implants, three were MT and one SLA resulting in an individual survival rate of 82.4% and 93.4%, respectively. In the failure group, all the fixtures had their screw emergence at the oral mucosa and recorded a torque range of less than 15 Ncm. The insertion torque statistically influenced the survival rate of the mini-implants (P < .05). Surface treatment, anatomical location, as well as soft tissue emergence were not statistically significant.


CONCLUSIONS
Surface characteristics did not appear to influence survival rates of immediately loaded mini-implants.
Chaddad
Karim
K
Department of Periodontics, University of Alabama at Birmingham, 1919 7th Ave South, SDB 412, Birmingham, AL 35294, USA. kcchaddad@gmail.com
Ferreira
André F H
AF
Geurs
Nico
N
Reddy
Michael S
MS
D000134:Acid Etching, Dental; D000293:Adolescent; D000328:Adult; D000368:Aged; D001863:Bone Screws; D045662:Dental Etching / Q000379:methods; D003764:Dental Materials / Q000737:chemistry; D004868:Equipment Failure; D005500:Follow-Up Studies; D006801:Humans; D008422:Materials Testing; D008875:Middle Aged; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D016382:Orthodontic Appliance Design; D013314:Stress, Mechanical; D013499:Surface Properties; D016019:Survival Analysis; D014025:Titanium / Q000737:chemistry; D014087:Tooth Movement Techniques / Q000295:instrumentation; D019415:Torque
D003764:Dental Materials; D014025:Titanium