Objective: To evaluate the bond strength of a self-etch bonding system using static loading and cyclic fatigue with shear testing. This is a two-part evaluation; the first part will evaluate shear testing, the second part tensile testing. Materials and Methods: Bovine teeth (n 5 82) were randomly distributed to either a self-etch (Transbond Plus) or total-etch (37% phosphoric-acid + Transbond XT) group. The static shear (SSBS) and cyclic shear (CSBS) bond strengths were measured 24 hours after the bonding of mesh-based brackets. The adhesive remnant index (ARI) and failure sites were evaluated. Results: The mean SSBS was 34.25 6 9.21 and 24.64 6 9.42 MPa for the total-and self-etch groups, respectively. CSBS was 24.07 6 0.65 MPa and 18.92 6 1.08 MPa for the total-and selfetch groups, respectively. Cyclic loading produced lower bond strengths compared to static testing for both adhesives; the difference was only statistically significant for the total-etch system. Comparison of the two materials showed a statistically significant difference between the two techniques. The total-etch had higher bond strengths than the self-etch bonding system. The samples showed a predominance of ARI scored of 2 and 1, and their bonding failure sites were cohesive within the composite. Conclusion: Cyclic loading, simulating occlusal forces, reduces the bond strength of both bonding systems. Even though the self-etch bonding system had lower shear bond strength than the totaletch system, both were still clinically acceptable. (Angle Orthod. 2011;81:783-787.)

Despite possessing knowledge about the health risks of smoking, high numbers of dental students continue to smoke and were exposed to secondhand smoke. Sex and family influence were the main pro-smoking risk factors, whereas increased knowledge of health risks was a protective factor. Tobacco control programs to reduce and/or prevent tobacco use among future dentists are needed.

OBJECTIVES:To compare orthodontic elastics with different force extension characteristics, thereby aiming to reduce the orthodontist's inventory for elastics.MATERIALS AND METHODS:Thirty nonextraction class I models were used to determine extension distances. Light, medium, and heavy forced Latex elastics of size 1/4 and 3/16 (from three manufacturers) were used. Thirty elastics from each pack were selected, for a total sample size of 540 elastics. Elastic force was measured at three extensions: three times the lumen (A), first molar to opposing canine (B), and second molar to opposing canine distance (C). Force values were compared with the analysis of variance followed by the post hoc Scheffe test.RESULTS:Mean distance for extensions B and C were 22.3 and 38.7 mm, respectively. There was a continuous but significant increase in the force of 1/4 elastics when stretched from A to extension C. A significant increase in the force level of 3/16 elastics was only noted when stretched from A to B. Overall, 1/4 elastics had a wider range of force coverage in the extensions used, compared to 3/16 elastics.CONCLUSIONS:The use of 1/4 elastics is sufficient to cover the range of forces in orthodontic treatment.

The multicomponent, 13-item scale was a valid and reliable measure of willingness to accept SHS exposure. If validated in other populations, it might be useful in planning and evaluating tobacco prevention programs in these populations.

Objectives:To explore the perceived effectiveness of pictorial health warning (PHW) labels required by the Gulf Cooperation Council, to compare them with the Food and Drug Administration–approved PHW labels, and to determine factors affecting their perceived effectiveness.Methods:A cross-sectional study using a convenience sample of adult smokers and nonsmokers was conducted. The data were collected through a self-administered online questionnaire. The perceived effectiveness scores of PHW labels were calculated and compared among different subgroups using the Kruskal-Wallis test and the Dunn multiple comparison test at a .05 significance level.Results:Of the 90 people invited to participate in the survey, 77 (86%) completed it, with 39 (50%) nonsmokers, 22 (29%) smokers, and 16 (21%) former smokers. Overall, labels having graphic images of illness or pathology are perceived to be most effective. Smokers generally perceived labels significantly less effective compared with former smokers and nonsmokers. Also, 55 respondents (71%) suggested that the presence of a telephone quit-line would be effective.Conclusions:Smoking status and image type had the most effect on the perceived effectiveness of the PHW labels on cigarette packs. Pictorial health warning labels with graphic images of pathology and a telephone quit-line are perceived to be most effective.