Moderators of physical activity and quality of life response to a physical activity intervention for breast cancer survivors.

PURPOSE: Moderate-to-vigorous physical activity (MVPA) can improve the quality of life (QoL) for breast cancer survivors (BCS), yet, most do not achieve 150 + weekly minutes of MVPA. This study investigated moderators of response to a physical activity (PA) behavior change intervention for BCS. METHODS: BCS (N = 222) were randomized to the 3-month intervention (BEAT Cancer) or usual care. Measurements occurred at baseline, post-intervention, and 3 months post-intervention. Measures included accelerometry, self-reported MVPA, and Functional Assessment of Cancer Therapy (FACT-General, FACT-Breast, physical well-being (PWB), social well-being (SWB), emotional well-being (EWB), functional well-being (FWB), additional concerns (AC), and Trial Outcome Index (TOI)). RESULTS: Adjusted linear mixed-model analyses indicated individuals ≤ 24 months post-diagnosis and who were single reported smaller increases in weekly self-reported MVPA than those > 24 months (44.07 vs 111.93) and partnered (- 16.24 vs. 49.16 min), all p < 0.05. As for QoL, participants < 12 months post-diagnosis who received chemotherapy experienced smaller improvements than those ≥ 12 months in FACT-General, FACT-Breast, PWB, and SWB scores. Survivors with a history of chemotherapy had smaller improvements in FACT-General, FACT-Breast, PWB, SWB, TOI, and AC scores, all p < 0.05. CONCLUSION: These findings indicate that being < 2 years post-diagnosis, single, and prior chemotherapy may limit MVPA and QOL responses to a PA intervention. Further studies are needed to determine if and/or what additional PA supports and resources these subgroups of BCS might find beneficial and effective. TRIAL REGISTRATION: ClinicalTrials.gov number: NCT00929617.

Social Cognitive Constructs Did Not Mediate the BEAT Cancer Intervention Effects on Objective Physical Activity Behavior Based on Multivariable Path Analysis.

BACKGROUND: Most breast cancer survivors do not meet physical activity recommendations. Understanding mediators of physical activity behavior change can improve interventions designed to increase physical activity in this at-risk population. PURPOSE: Study aims were to determine the 3-month Better Exercise Adherence after Treatment for Cancer (BEAT Cancer) behavior change intervention effects on social cognitive theory constructs and the mediating role of any changes on the increase in accelerometer-measured physical activity previously reported. METHODS: Post-treatment breast cancer survivors (N = 222) were randomized to BEAT Cancer or usual care. Assessments occurred at baseline, 3 months (M3), and 6 months (M6). Adjusted linear mixed model analysis of variance determined intervention effects on walking self-efficacy, outcome expectations, goal setting, and perceived barrier interference at M3. Path analysis determined mediation of intervention effects on physical activity at M6 by changes in social cognitive constructs during the intervention (i.e., baseline to M3). RESULTS: BEAT Cancer significantly improved self-efficacy, goals, negative outcome expectations, and barriers. Total path analysis model explained 24 % of the variance in M6 physical activity. There were significant paths from randomized intervention group to self-efficacy (ß = 0.15, p < .05) and barriers (ß = -0.22, p < .01). Barriers demonstrated a borderline significant association with M6 physical activity (ß = -0.24, p = .05). No statistically significant indirect effects were found. CONCLUSIONS: Although BEAT Cancer significantly improved social cognitive constructs, no significant indirect effects on physical activity improvements 3 months post-intervention were observed (NCT00929617).

Breast Cancer Survivors' Exercise Preferences Change During an Exercise Intervention and are associated with Post-Intervention Physical Activity.

Purpose Exercise program preferences are important for designing physical activity (PA) interventions; yet may change following an intervention. Further, the relationship between preferences and PA behavior change is unclear. This study evaluated exercise program preferences among breast cancer survivors (BCS) before and after a behavioral intervention and associations between program preferences and PA change. Methods BCS were randomized to the BEAT Cancer intervention (n = 110) or written materials (n = 112). Questionnaires assessed exercise program preferences. Minutes per week of moderate-to-vigorous PA (MVPA) were accelerometer-measured and self-reported at baseline (M0), post-intervention (M3), and 3-month follow-up (M6). Results At M0, the majority of intervention group participants preferred exercising with others (62%) yet shifted to preferring exercising alone (59%) at M3 ( p < 0.001). Furthermore, preferring exercising with others at M0 was associated with greater increases in self-reported MVPA between M0 and M6 (124.2 ± 152 vs. 53.1 ± 113.8, p = 0.014). BCS preferring facility-based exercise decreased after the BEAT Cancer intervention (14% vs. 7%, p = 0.039) and preferring exercising at home/had no preference at M0 had greater improvements in accelerometer-measured MVPA from M0 to M3 (74.3 ± 118.8 vs. -2.3 ± 78.4, p = 0.033) and M0 to M6 (44.9 ± 112.8 vs. 9.3 ± 30.4, p = 0.021). Exercise program preferences regarding mode of counseling, training supervision, and type of exercise changed from M0 to M3 but were not associated with changes in MVPA. Conclusion Findings suggest BCS exercise program preferences may change after an intervention and be associated with changes in MVPA. Understanding the role of PA preferences will better inform the design and success of PA behavior change interventions. ClinicTrials.gov, ClinicalTrials.gov number: NCT00929617.

Comparative three-dimensional analysis of initial biofilm formation on three orthodontic bracket materials.

INTRODUCTION: The purpose of the present study was to investigate and compare early biofilm formation on biomaterials, which are being used in contemporary fixed orthodontic treatment. METHODS: This study comprised 10 healthy volunteers (5 females and 5 males) with a mean age of 27.3 +-3.7 years. Three slabs of different orthodontic materials (stainless steel, gold and ceramic) were placed in randomized order on a splint in the mandibular molar region. Splints were inserted intraorally for 48 h. Then the slabs were removed from the splints and the biofilms were stained with a two color fluorescence assay for bacterial viability (LIVE/DEAD BacLight-Bacterial Viability Kit 7012, Invitrogen, Mount Waverley, Australia). The quantitative biofilm formation was analyzed by using confocal laser scanning microscopy (CLSM). RESULTS: The biofilm coverage was 32.7 ± 37.7% on stainless steel surfaces, 59.5 ± 40.0% on gold surfaces and 56.8 ± 43.6% on ceramic surfaces. Statistical analysis showed significant differences in biofilm coverage between the tested materials (p=0.033). The Wilcoxon test demonstrated significantly lower biofilm coverage on steel compared to gold (p=0.011). Biofilm height on stainless steel surfaces was 4.0 ± 7.3 µm, on gold surfaces 6.0 ± 6.6 µm and on ceramic 6.5 ± 6.0 µm. The Friedman test revealed no significant differences between the tested materials (p=0.150). Pairwise comparison demonstrated significant differences between stainless steel and gold (p=0.047). CONCLUSION: Our results indicate that initial biofilm formation seemed to be less on stainless steel surfaces compared with other traditional materials in a short-term observation. Future studies should examine whether there is a difference in long-term biofilm accumulation between stainless steel, gold and ceramic brackets.

The influence of simulated aging on the mechanical properties of orthodontic elastomeric chains without an intermodular link.

OBJECTIVE: Orthodontic elastomeric chains are a main component in orthodontic therapy with fixed vestibular or lingual appliances. The objective of this study was to investigate the influence of artificial aging on the mechanical properties of orthodontic elastomeric chains (power chains, PCs) without an intermodular link using a test setup according to DIN EN ISO 21606:2007. MATERIAL AND METHODS: In this study, 11 types of PCs supplied by seven manufacturers were investigated. Four groups with 10 specimens each were randomly generated for each type. Samples were separately mounted in a universal testing machine and extended by 300% (four times their initial length) at a crosshead rate of 100 mm/min and were held at this position for five seconds. The chain length was then reduced to three times the initial length (extension by 200%) and kept for 30 s. Then, within the control group (t = 0) and the force Fmin was recorded before extension until failure was performed and force (Fmax) and length (Lmax) at failure were determined. After prestretching, specimens of the three other groups were stored in water at 37°C with its three times initial length for one day (t = 1), 14 days (t = 2), and 28 days (t = 3), respectively. The specimens were then placed in the universal testing machine and the residual force (Fmin) measured, so as to subsequently extend them until failure at Fmax and Lmax. Data were statistically analyzed by one-way analysis of variance; the level of significance was set at p = 0.05. RESULTS: Statistical analysis revealed significant differences in Fmax, Fmin, and Lmax in each group (t = 0 to t = 3) between the various manufacturers (p < 0.001). Moreover, artificial aging significantly influenced Fmax, Fmin, and Lmax (p < 0.001). CONCLUSION: The orthodontist should consider both the mechanical properties of PCs and the duration of these appliances' application when treating patients. Artificial aging had a significant influence on the parameters we determined (p <0.001).

Comparative analysis of long-term biofilm formation on metal and ceramic brackets.

OBJECTIVE: To test the null hypothesis that stainless steel and ceramic brackets show no differences in biofilm adhesion. MATERIALS AND METHODS: Twenty adolescents (6 boys, 14 girls) who had received fixed orthodontic therapy for 18.9 ± 3.2 months were divided into a metal and a ceramic bracket group. Thirty brackets per group were taken from central incisors, canines, and second premolars and quantitatively analyzed for biofilm coverage with the Rutherford backscattering detection method. Five micrographs were obtained per bracket with views from the buccal, mesial, distal, gingival, and occlusal aspects, resulting in a total of 300 images. Biofilm formation between groups was compared using the Mann-Whitney U-test (α = .05). RESULTS: Total biofilm formation was 12.5% ± 5.7% (3.3 ± 1.6 mm(2)) of the surface on metal and 5.6% ± 2.4% (1.5 ± 0.6 mm(2)) on ceramic brackets. Differences between groups were statistically significant (P < .05). A pairwise comparison of biofilm formation revealed significantly lower biofilm formation on ceramic brackets with respect to intraoral location (central incisor, canine, second premolar) and bracket surface (buccal, mesial, distal). CONCLUSIONS: The hypothesis was rejected. The results indicate that ceramic brackets exhibit less long-term biofilm accumulation than metal brackets.

Influence of orthognathic surgery on periodontal tissues: short-term results.

OBJECTIVE: The present prospective study aimed at evaluating the influence of orthognathic surgery on mucogingival tissues and the subgingival microflora. PATIENTS AND METHODS: Fifteen consecutively-treated patients with a mean age of 24.9±7.7 years were included in this study. The surgical interventions comprised the Le Fort I osteotomy of the maxilla and/or sagittal split osteotomy of the mandible. The following periodontal and microbial parameters were measured preoperatively (T(0)) as well as 1 week (T(1)) and 6 weeks (T(2)) postoperatively: pocket probing depth (PPD), gingival recession (GR), clinical attachment level (CAL), bleeding on probing (BOP), plaque index (PI), and changes in the subgingival microflora. Periodontal parameters were calculated for all sites as well as for buccal and oral sites separately. For statistical analysis, the general linear model and paired t test were applied (level of significance: p<0.05). RESULTS: PPD readings increased significantly on oral tooth sites when T(0) values were compared to T(1) (p=0.009) and T(2 )values (p=0.042). GR increased significantly on buccal sites from 0.10±0.16 mm at baseline to 0.21±0.23 mm at T(1) (p=0.013) and 0.31±0.31 mm at T(2) (p=0.001). Furthermore, we noted significant changes in the CAL (oral sites) and PI (buccal and oral sites). We observed no significant differences in BOP and periodontopathogenetic bacteria. CONCLUSION: Orthognathic surgery has a statistically significant effect on the development of gingival recessions. However, this effect may not necessarily clinically impair the esthetic appearance.

Tensile properties of orthodontic elastomeric chains.

AIM: Orthodontic elastomeric chains are a main component in orthodontic therapy employing labial or lingual appliances. The aim of this study was to investigate the tensile properties of orthodontic elastomeric chains with a test setup according to ISO 21606:2007. MATERIAL AND METHODS: Orthodontic elastomeric chains of eight manufacturers with and without an intermodular link were obtained from commercially-available stock, yielding 23 groups with ten specimens each. Samples were mounted in a universal testing machine and extended at a rate of 100 mm/min to four times the initial length and held for 5 seconds. After 5 seconds, the chain lengths were reduced to an extension of three times the initial length and held for 30 seconds before extension until failure. Forces at four times the test length (Fmax1), three times the initial length (Fmin) as well as force (Fmax2) and length (Lmax) at failure were recorded. Data were statistically analyzed by one-way analysis of variance using SPSS® 17. The level of significance was set at p = 0.05. RESULTS: Statistical analysis revealed significant differences in Fmax1, Fmin, Fmax2 and Lmax among the various manufacturers. Fmax1 ranged between 9.1 N and 23.2 N, Fmin ranged between 1.5 N and 3.0 N, Fmax2 ranged between 15.7 N and 34.0 N, and Lmax ranged between 425% and 629% of the initial length. CONCLUSIONS: The tensile properties of different manufacturers of elastomeric orthodontic chains differ statistically significantly. Hence the amount of orthodontic force that is applied depends significantly on the type of elastomeric chains used in combination with labial or lingual appliances.