Peel bond strength of resilient liner modified by the addition of antimicrobial agents to denture base acrylic resin

In order to prolong the clinical longevity of resilient denture relining materials and reduce plaque accumulation, incorporation of antimicrobial agents into these materials has been proposed. However, this addition may affect their properties.

Objective

This study evaluated the effect of the addition of antimicrobial agents into one soft liner (Soft Confort, Dencril) on its peel bond strength to one denture base (QC 20, Dentsply).

Material and Methods

Acrylic specimens (n=9) were made (75x10x3 mm) and stored in distilled water at 37ºC for 48 h. The drug powder concentrations (nystatin 500,000U - G2; nystatin 1,000,000U - G3; miconazole 125 mg - G4; miconazole 250 mg - G5; ketoconazole 100 mg - G6; ketoconazole 200 mg - G7; chlorhexidine diacetate 5% - G8; and 10% chlorhexidine diacetate - G9) were blended with the soft liner powder before the addition of the soft liner liquid. A group (G1) without any drug incorporation was used as control. Specimens (n=9) (75x10x6 mm) were plasticized according to the manufacturers'' instructions and stored in distilled water at 37ºC for 24 h. Relined specimens were then submitted to a 180-degree peel test at a crosshead speed of 10 mm/min. Data (MPa) were analyzed by analysis of variance (α=0.05) and the failure modes were visually classified.

Results

No significant difference was found among experimental groups (p=0.148). Cohesive failure located within the resilient material was predominantly observed in all tested groups.

Conclusions

Peel bond strength between the denture base and the modified soft liner was not affected by the addition of antimicrobial agents.     

Get Up, Get Out, Get Moving: An Interactive Tool for Education at Your Local School

Background

Childhood obesity is a growing problem in America. Orthopaedic surgeons have an opportunity to interact with communities to educate children about healthy eating and physical activity. The American Academy of Orthopedic Surgeons (AAOS) Leadership Fellows Program [1] Class of 2012 created a presentation for AAOS members to bring to local schools. The goal was to teach the children about the potential complications of childhood obesity and the benefits of healthy living.

Questions/purposes

We describe a program in which orthopaedic surgeons gave presentations to elementary school students about healthy eating and activity and the effects that extra weight can have on their bones.

Methods

Each of the five members of the Leadership Fellows Program [1] 2012 class (JW, EM, MP, MR, MF) presented to a school in his or her hometown. The program was presented to 210 fifth grade children throughout the country. Before and after the presentation, students took a six-question multiple-choice quiz and answers compared to assess improvement in knowledge.

Results

The average number of answers correct before the presentation was 4.5 out of six, and the average after the presentation was six of six. The presentations were well received, and the students and their teachers invited each presenter back the next year.

Conclusions

The improvement in quiz scores demonstrated interest among the students in that they paid attention and understood the content. The children appeared enthusiastic to learn about this subject, and the schools were enthusiastic to include the curriculum.     

Incidence and Consequence of Close Margins in Patients with Ductal Carcinoma-In Situ Treated with Mastectomy: Is Further Therapy Warranted?

Background

The impact of close margins in patients with ductal carcinoma-in situ (DCIS) treated with mastectomy is unclear; however, this finding may lead to a recommendation for postmastectomy radiotherapy (PMRT). We sought to determine the incidence and consequences of close margins in patients with DCIS treated with mastectomy.

Methods

The records of 810 patients with DCIS treated with mastectomy from 1996 through 2009 were reviewed. Clinical and pathologic factors were analyzed with respect to final margin status. Median follow-up was 6.3 years.

Results

Overall, 94 patients (11.7 %) had close margins (positive, n = 5; negative but ≤1 mm, n = 54; 1.1–2.9 mm, n = 35). Independent risk factors for close margins included multicentricity, pathologic lesion size ≥1.5 cm, and necrosis, but not age, use of skin-sparing mastectomy, or immediate reconstruction (p > 0.05). Seven patients received PMRT, and none had a locoregional recurrence (LRR). Among the remaining 803 patients, the 10-year LRR rate was 1 % (5.0 % for margins ≤1 mm, 3.6 % for margins 1.1–2.9 mm, and 0.7 % for margins ≥3 mm [p < 0.001]). The 10-year rate of contralateral breast cancer was 6.4 %. On multivariate analysis, close margins was the only independent predictor of LRR (p = 0.005).

Conclusions

Close margins occur in a minority of patients undergoing mastectomy for DCIS and is the only independent risk factor for LRR. As the LRR rate in patients with close margins is low and less than the rate of contralateral breast cancer, PMRT is not warranted except for patients with multiple close/positive margins that cannot be surgically excised.     

Safety of repetitive nerve stimulation in patients with cardiac implantable electronic devices

Introduction: Pacemakers and implantable cardioverter-defibrillators (ICDs) are vulnerable to inappropriate sensing of electromagnetic interference (EMI), such as from nerve conduction studies. We conducted a prospective study to assess the safety of repetitive nerve stimulation (RNS). Methods: Fourteen patients undergoing insertion of 10 ICDs and 4 pacemakers under general anesthesia received RNS of the median, axillary, and spinal accessory nerves at 2 HZ and 50 HZ . We recorded detection of EMI and whether or not this resulted in an arrhythmia diagnosis or change in pacing output. Results: EMI was visible in 2 ICDs, without spurious tachyarrhythmia detection. EMI was observed in 3 of the 4 pacemakers, which led to pacing inhibition and a pause in 2, both of which were programmed to a unipolar sensing configuration. Conclusions: RNS is safe in patients with ICDs. In pacemaker patients, RNS appears safe during bipolar sensing, but caution is recommended in pacemaker patients with unipolar sensing. Muscle Nerve 47: 840–844, 2013