Minimal tooth preparation for posterior monolithic ceramic crowns: Effect on the mechanical behavior,reliability and translucency

ObjectiveDespite the increased use of monolithic crowns, their performance has yet to be determined when the minimal tooth preparation (MTP) principle is considered. The goal of this study was to evaluate the effect of MTP on the mechanical behavior, reliability and translucency of posterior monolithic ceramic crowns.MethodsDentin analogues were machined using two preparation designs (0.5 or 1 mm reduction) to receive first molar crowns in order to evaluate the monolithic crown performance. Next, 126 crowns were divided (21/g) according to the material (High translucent zirconia – YZHT, Zirconia reinforced lithium silicate – ZLS and Hybrid ceramic – HC) and thickness (0.5 or 1 mm). Tensile stress concentration was calculated using the finite element method. The crowns were adhesivelly cemented and step stress fatigued to calculate reliability for missions at 600 and 1000 N. Translucency was analyzed in 10 discs of each material and thickness.ResultsHigher stress concentration was found in thinner crowns and those with higher elastic modulus. YZHT crowns were suspended when fatigue reached 1500 N load, thus 1-parameter Weibull was used to analyze the data. Reliability was only affected by thickness at 1000 N. ZLS.5 showed lower survival than HC.5, which was similar to the groups that presented 100% survival. YZHT showed the highest strength and data scattering. ZLS1 (22.3 ± 1.4) presented higher translucency than HC1 (19.2 ± 0.6) and YZHT1 (12.0 ± 2.9), whereas ZLS.5 and HC.5 were similar to each other (26.5 ± 2.3, 26.7 ± 2.2) and superior to YZHT.5 (12.7 ± 1.2).SignificanceHC.5 combined high reliability and translucency with low stress concentration, yielding better crown performance and tooth preservation.     

Heterozygous mutations in the PALB2 hereditary breast cancer predisposition gene impact on the three‐dimensional nuclear organization of patient‐derived cell lines

PALB2/FANCN is a BRCA1‐ and BRCA2‐interacting Fanconi Anemia (FA) protein crucial for key BRCA2 genome caretaker functions. Heterozygous germline mutations in PALB2 predispose to breast cancer and biallelic mutations cause FA. FA proteins play a critical role in the telomere maintenance pathway, with telomeric shortening observed in FA cells. Less is known about telomere maintenance in the heterozygous state. Here, we investigate the roles of PALB2 heterozygous mutations in genomic instability, an important carcinogenesis precursor. Patient‐derived lymphoblastoid (LCL) and fibroblast (FCL) cell lines with monoallelic truncating PALB2 mutations were investigated using a combination of molecular imaging techniques including centromeric FISH, telomeric Q‐FISH and spectral karyotyping (SKY). Mitomycin C and Cisplatin sensitivity was assayed via cellular metabolism of WST‐1. The PALB2 c.229delT FCL showed increases in telomere counts associated with increased mean intensity compared with two wild‐type FCLs generated from first‐degree relatives (P =1.04E‐10 and P =9.68E‐15) and it showed evidence of chromosomal rearrangements. Significant differences in centromere distribution were observed in one of three PALB2 heterozygous FCLs analyzed when compared with PALB2 wild‐type, BRCA1 and BRCA2 heterozygous FCLs. No significant consistently increased sensitivity to Mitomycin C or Cisplatin was observed in LCLs. Our results are suggestive of an altered centromere distribution profile and a telomere instability phenotype. Together, these may indicate critical nuclear organization defects associated with the predisposition to transformation and early stage development of PALB2‐related cancers. © 2013 Wiley Periodicals, Inc.     

Occlusal splint for sleep bruxism: an electromyographic associated to Helkimo Index evaluation

This study aims to evaluate long-term effects of using an occlusal splint in patients with sleep bruxism (SB), using surface electromyography (EMG) of masseter and temporalis muscles, as well as the Helkimo Index. The subjects were 15 individuals aged from 19 to 29 years, bearers of SB, with presence of signs and symptoms of temporomandibular disorders (TMD), which never have used occlusal splints. The subjects answered the Helkimo's Index and underwent EMG before and after 60 days of occlusal splints use. There was no indication of a significant decrease in mean EMG levels over the therapy in the muscles. A significant decrease in TMD signs and symptoms were observed in SB patients after 60 days of occlusal splints therapy.     

Proximal Esophageal Contractions in Laryngectomized Patients

After laryngectomy for treatment of laryngeal cancer, the distal esophageal contractions have low amplitude. Our hypothesis is that proximal esophageal contractions are also impaired. We studied the proximal esophageal contractions in 20 laryngectomized patients (16 men) with a mean age of 44.2 years, 12 rehabilitated patients with esophageal speech, and 12 controls (7 men, mean age of 46.5 years). We used the manometric method with continuous perfusion. All subjects were studied in the sitting position and performed five swallows of a 5-ml bolus of water alternated with five dry swallows. The contractions were measured 2 cm below the high-pressure zone of the pharyngoesophageal transition. The results showed that the amplitude and duration of contractions were different in laryngectomized patients compared with controls. The amplitude of contractions of patients (wet swallows: 37.3 ± 20.7 mmHg, mean ± SD) was lower than that of controls (81.1 ± 31.7 mmHg). The duration of contractions was also lower in laryngectomized patients (2.2 ± 0.7 s) than in controls (2.6 ± 0.6 s). We conclude that the proximal esophageal contraction amplitude and duration of laryngectomized patients are lower than controls, a fact suggesting that laryngectomy may affect the proximal esophageal contractions.     

Short- and Medium-Term Efficacy of a Web-Based Computer-Tailored Nutrition Education Intervention for Adults Including Cognitive and Environmental Feedback: Randomized Controlled Trial

Background

Web-based, computer-tailored nutrition education interventions can be effective in modifying self-reported dietary behaviors. Traditional computer-tailored programs primarily targeted individual cognitions (knowledge, awareness, attitude, self-efficacy). Tailoring on additional variables such as self-regulation processes and environmental-level factors (the home food environment arrangement and perception of availability and prices of healthy food products in supermarkets) may improve efficacy and effect sizes (ES) of Web-based computer-tailored nutrition education interventions.

Objective

This study evaluated the short- and medium-term efficacy and educational differences in efficacy of a cognitive and environmental feedback version of a Web-based computer-tailored nutrition education intervention on self-reported fruit, vegetable, high-energy snack, and saturated fat intake compared to generic nutrition information in the total sample and among participants who did not comply with dietary guidelines (the risk groups).

Methods

A randomized controlled trial was conducted with a basic (tailored intervention targeting individual cognition and self-regulation processes; n=456), plus (basic intervention additionally targeting environmental-level factors; n=459), and control (generic nutrition information; n=434) group. Participants were recruited from the general population and randomly assigned to a study group. Self-reported fruit, vegetable, high-energy snack, and saturated fat intake were assessed at baseline and at 1- (T1) and 4-months (T2) postintervention using online questionnaires. Linear mixed model analyses examined group differences in change over time. Educational differences were examined with group×time×education interaction terms.

Results

In the total sample, the basic (T1: ES=–0.30; T2: ES=–0.18) and plus intervention groups (T1: ES=–0.29; T2: ES=–0.27) had larger decreases in high-energy snack intake than the control group. The basic version resulted in a larger decrease in saturated fat intake than the control intervention (T1: ES=–0.19; T2: ES=–0.17). In the risk groups, the basic version caused larger decreases in fat (T1: ES=–0.28; T2: ES=–0.28) and high-energy snack intake (T1: ES=–0.34; T2: ES=–0.20) than the control intervention. The plus version resulted in a larger increase in fruit (T1: ES=0.25; T2: ES=0.37) and a larger decrease in high-energy snack intake (T1: ES=–0.38; T2: ES=–0.32) than the control intervention. For high-energy snack intake, educational differences were found. Stratified analyses showed that the plus version was most effective for high-educated participants.

Conclusions

Both intervention versions were more effective in improving some of the self-reported dietary behaviors than generic nutrition information, especially in the risk groups, among both higher- and lower-educated participants. For fruit intake, only the plus version was more effective than providing generic nutrition information. Although feasible, incorporating environmental-level information is time-consuming. Therefore, the basic version may be more feasible for further implementation, although inclusion of feedback on the arrangement of the home food environment and on availability and prices may be considered for fruit and, for high-educated people, for high-energy snack intake.

Trial Registration

Netherlands Trial Registry NTR3396; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=3396 (Archived by WebCite at http://www.webcitation.org/6VNZbdL6w).     

Successful Treatment of Carbapenemase-Producing Pandrug-Resistant Klebsiella pneumoniae Bacteremia

New antibiotic options are urgently needed for the treatment of carbapenem-resistant Enterobacteriaceae infections. We report a 64-year-old female with prolonged hospitalization following an intestinal transplant who developed refractory bacteremia due to a serine carbapenemase-producing pandrug-resistant isolate of Klebsiella pneumoniae. After failing multiple antimicrobial regimens, the patient was successfully treated.