Pain experience during initial alignment with a self-ligating and a conventional fixed orthodontic appliance system. A randomized controlled clinical trial.
OBJECTIVE
To test the hypotheses that (1) there is no difference in the pain experience during the week following initial placement of two orthodontic appliances (SmartClip and Victory; 3M Unitek, Monrovia, Calif); and (2) there is no difference in the pain experience during removal and insertion of orthodontic archwires with these brackets.


METHODS
Sixty-six consecutive patients were treated with a self-ligating bracket system (SmartClip) or a conventional appliance (Victory) on the basis of computer-generated random allocation. After appliance placement and engagement of a 0.016'' nickel-titanium archwire, pain experience was recorded after 4, 24, and 72 hours and after 7 days with the use of a visual analog system (VAS) questionnaire. At a subsequent visit, participants documented pain experiences during removal and insertion of 0.019 x 0.025'' archwires on an additional 100 mm VAS questionnaire. Independent t-tests and analyses of covariance were used to analyze normally distributed data; the Mann-Whitney U-test was used for skewed distributions.


RESULTS
Forty-eight (72.2%) and fifty-one (77.3%) subjects completed the first and second parts of the study, respectively. Bracket type had no influence on pain experience at 4 hours (P = .958), 24 hours (P = .289), 72 hours (P = .569), and 7 days (P = .756) following appliance placement. However, bracket type significantly influenced pain experience during archwire removal (P = .001) and insertion (P = .013).


CONCLUSIONS
Hypothesis 1 cannot be rejected. The bracket type had no effect on subjective pain experience during the first week after initial placement of two preadjusted orthodontic appliances. Hypothesis 2 was rejected. Significantly greater discomfort was experienced during archwire insertion and removal with the SmartClip appliance.
Fleming
P S
PS
Royal London Hospital, London, UK. padhraigfleming@hotmail.com
Dibiase
A T
AT
Sarri
G
G
Lee
R T
RT
D000293:Adolescent; D003722:Dental Alloys; D005157:Facial Pain / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D009532:Nickel; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets / Q000009:adverse effects*; D009969:Orthodontic Wires / Q000009:adverse effects*; D009971:Orthodontics, Corrective / Q000009:adverse effects / Q000295:instrumentation; D010147:Pain Measurement; D013193:Stainless Steel; D011795:Surveys and Questionnaires; D013997:Time Factors; D014025:Titanium
D003722:Dental Alloys; C040654:titanium nickelide; D013193:Stainless Steel; D009532:Nickel; D014025:Titanium