Preliminary evaluation of a novel polymer nanocomposite as a root-end filling material.

AIM: To evaluate two nanoparticle-enhanced polymer root-end filling materials (NERP1 and NERP2) on the initial apical seal as compared to a polymer-based commercial compomer. METHODOLOGY: One hundred and forty extracted roots with completely formed apices were resected 3 mm from the apex. Cavities were then prepared in the apical openings of the resected root ends using an ultrasonic handpiece to a depth of 3 mm. The roots were then randomly divided into five groups to receive one of five root-end filling materials. Roots in groups 1 and 2 received NERP1 and NERP2, whilst those in groups 3 and 4 received identical polymers as groups 1 and 2 but without nanoparticle addition (RP1 and RP2, respectively). The root-end cavities for the fifth group were filled with commercially available root-end filling compomer. Roots were mounted in a dual-chamber leakage apparatus and inoculated coronally with Enterococcus faecalis. Turbidity of the apical broth was assessed daily for 4 weeks as a sign of initial leakage. The results were statistically analysed using odds ratio and Fisher's chi-square analysis. RESULTS: Nanoparticle-enhanced root-end filling polymer 1 displayed significantly fewer leaked samples compared to all other tested groups as early as 5 days, whilst NERP2 was not significantly different compared to other groups. Odds ratio analysis revealed leakage of the commercial compomer was 12 times more likely than NERP1. CONCLUSION: Nanoparticle-enhanced root-end filling polymer 1 can reduce apical microleakage significantly under laboratory conditions.

Hospital- and community-based surveillance of methicillin-resistant Staphylococcus aureus: previous hospitalization is the major risk factor.

OBJECTIVE: The purpose of the study was to determine the incidence and risk factors for the acquisition of methicillin-resistant Staphylococcus aureus (MRSA) in our community. DESIGN: This study used a cross-sectional design to assess patients colonized or infected with MRSA. PATIENTS: The study population consisted of residents of London, Ontario, Canada, who were identified as MRSA-positive for the first time in 1997. SETTING: All acute- and chronic-care hospitals, long-term healthcare facilities, and community physicians' offices in the city of London participated in the study. MAIN OUTCOME MEASURE: Incidence of MRSA in the community, risk factors for acquisition, especially previous hospitalization over a defined period, and strain type were evaluated. RESULTS: In 1997, 331 residents of London were newly identified as MRSA-positive, representing an annual incidence of 100/100,000 persons (95% confidence interval, 88.8-110.7). Thirty-one (9.4%) individuals were not healthcare-facility patients in the previous month, and 11 (3.3%), 10 (3.0%), and 6 (1.8%) individuals had no such contact in the previous 3, 6, and 12 months, respectively. One hundred seventy-seven strains, including five of the isolates from patients with no healthcare-facility contact in the previous year, were typed. One hundred sixty (90.3%) of these isolates, including all typed strains from patients with no healthcare facility contact, belonged to a single clone. CONCLUSION: These findings demonstrate that the incidence of MRSA is higher than previously reported and that hospital contact is the single most important risk factor for the acquisition of MRSA in our community. Screening for MRSA in previously hospitalized patients at the time of hospitalization may reduce nosocomial spread and indirectly reduce the incidence of MRSA in the community.

Proximal fibular osteochondroma with associated peroneal nerve palsy: a review of six cases.

Osteochondroma of the proximal fibula is relatively common, but reports of this lesion in conjunction with peroneal nerve palsy have been scarce. Six patients with peroneal nerve palsy and fibular exostosis are presented with the results of electrical studies, radiographic evaluation, physical examination, and operative treatment. A wide variation in presentation and outcome was observed. Preoperative and postoperative electromyography and nerve-conduction studies are useful in evaluation. A heightened awareness of this entity is required to avoid permanent damage in an otherwise treatable condition.