Tag: statistics

Gen Dent. 2022 Jan-Feb;70(1):65-71.

ABSTRACT

The objective of this study was to evaluate the effect of cement thickness and luting cement type on the push-out bond strength of glass fiber posts (GFPs) to root dentin. Sixty human maxillary root-filled canines or premolars with single straight roots were randomly divided into 6 groups (n = 10) according to the GFP configuration (conventional or relined with composite resin) and the cement used (RelyX U200, Ketac Cem, or Allcem Core). After endodontic treatment and GFP cementation, all of the roots were sectioned perpendicular to their long axis to obtain 1.0-mm-thick slices (n = 6 per group), which were mounted on a universal testing machine and submitted to a push-out test. The data (n = 45 to 51 specimens per group because of pretest failures) were analyzed by means of 2-way analysis of variance (ANOVA) and Tukey tests (α = 0.05). The type of failure was determined under a stereomicroscope, and representative specimens were observed with scanning electron microscopy. Significant interactions between the cements and GFP configurations were detected in the coronal and apical thirds (P < 0.05; 2-way ANOVA). For the coronal third, both RelyX U200 cement groups exhibited the greatest push-out bond strengths but were not significantly different from the Allcem Core relined group. For the middle third, no statistically significant interactions were observed between the cements and GFP configurations (P = 0.232; 2-way ANOVA). Adhesive failure between the dentin and cement layer was the most frequently observed failure mode. As expected, because of the composite resin added to relined GFPs, the cement layer was thinner in those groups. The type of cement used played an important role in the push-out bond strength.

PMID:34978994

Gen Dent. 2022 Jan-Feb;70(1):22-25.

ABSTRACT

The aim of this study was to compare the effectiveness of a reciprocating file (Reciproc) and a rotary retreatment file (Mtwo retreatment [Mtwo-R]) for the removal of filling material during root canal retreatment. A total of 30 mandibular molars with a mesial root curvature between 20° and 40° were selected and prepared using a Reciproc R25 file. The canals were filled using the lateral condensation technique and a root canal sealer. The specimens were randomly allocated into 2 groups according to the retreatment technique used (n = 15): a Reciproc R25 file or Mtwo-R 15/.05 and 25/.05 files. After retreatment, the specimens were longitudinally sectioned and photographed with an operating microscope under ×10 magnification. The percentage of total remaining filling material and the percentages in the cervical, middle, and apical thirds of the specimens were calculated. The Student t test was used for statistical comparisons of the 2 groups, and the analysis of variance followed by Tukey test was used to verify differences among the root thirds within each group. No statistically significant difference between the 2 groups was detected in the percentage of total remaining filling material (P = 0.87) or the percentage in any of the thirds of the root canals (P > 0.05) after reinstrumentation. In both groups, there was a significantly greater amount of remaining material in the apical third (P < 0.05). The results suggested that there is no difference between the 2 systems in their effectiveness at removing filling material.

PMID:34978985

Gen Dent. 2022 Jan-Feb;70(1):30-33.

ABSTRACT

The purpose of this in vitro study was to compare the 3- and 90-day bond strengths of 3 cements used for luting metal-ceramic crowns. Zinc phosphate cement (ZPC; SS White), resin-modified glass ionomer cement (RMGIC; Fuji Plus), and self-adhesive resin cement (SARC; RelyX U200) were assessed in 2 different treatment conditions (with and without microsandblasting of the alloy) and at 2 experimental times (3 days [E1] and 90 days [E2] after cementation). The buccal surfaces of 84 bovine teeth were ground until the dentin was exposed, and 84 nickel-chromium alloy plates cast from a resin model were cemented to the dentin surfaces with 1 of the 3 cements (n = 28). In half of the specimens of each group (n = 14), the bonding surfaces of the nickel-chromium plates received 6 seconds of microsandblasting with 45-μm aluminum oxide particles prior to cementation. The compressive shear bond strengths of the specimens were evaluated in a universal testing machine at E1 and E2 (n = 7). The SARC group showed the greatest bond strength, followed by the RMGIC group, while the bond strength of the ZPC group was significantly lower (P < 0.01). For the RMGIC specimens subjected to microsandblasting, there was a statistically significant difference between the mean bond strengths at E1 and E2 (P = 0.040). All of the other cement and treatment groups showed statistically similar adhesion results at E1 and E2 (P > 0.05). The complementary test by Šidák revealed that the cements Fuji Plus and RelyX U200 showed higher values at E2 and were statistically similar to each other (P > 0.05). Although RMGIC specimens showed a lower initial bond strength than SARC specimens, the fact that the microsandblasted RMGIC subgroup was the only one that demonstrated a significant increase in bond strength with aging suggests that RMGIC can be a material of first choice because it also costs less than SARC.

PMID:34978987

Acta Med Port. 2021 Oct 1;34(10):669-676. doi: 10.20344/amp.15706. Epub 2021 Oct 1.

ABSTRACT

INTRODUCTION: Rotavirus infections are a leading cause of severe acute gastroenteritis in children under five years old. In December 2019, Portugal announced the inclusion of the rotavirus vaccine, already available for private purchase, in the National Immunization Program. We present the first nationwide analysis of the burden and trends of rotavirus and acute gastroenteritis hospital episodes in children under five years old in mainland Portugal (2014 – 2017).

MATERIAL AND METHODS: We used the hospital morbidity database and the Death Certificate Information System to identify hospital episodes and deaths of rotavirus and acute gastroenteritis based on the codes of the International Classification of Diseases. We described the number and rates of hospital episodes disaggregated by age group, sex, geographical units, and the seasonality and trends over the study period.

RESULTS: On average, during the study period, there were 1985 annual hospital episodes among children under five years old. The annual rate was 48.0/10 000 children (95% CI 46.9 – 49.0). Rates were consistently higher in younger children, and 67.8% episodes occurred in children under 24 months. We found a seasonal pattern with a major peak in the early spring.

DISCUSSION: Our results were consistent with the current knowledge on rotavirus and acute gastroenteritis hospital episodes in Europe. Additional studies are needed to identify the risk factors and high-risk groups for hospital attendance.

CONCLUSION: Rotavirus and acute gastroenteritis hospital episodes in children under five years old in mainland Portugal represent an important health and economic burden. In the future, monitoring this burden and these trends in relation with rotavirus vaccine coverage could be useful in order to assess the impact of the vaccination programme on the change in hospital episodes.

PMID:34978977 | DOI:10.20344/amp.15706

J Asthma. 2022 Jan 3:1-22. doi: 10.1080/02770903.2021.2025389. Online ahead of print.

ABSTRACT

Objective: The purpose of this study was to examine the effect of Medicaid expansion on asthma-related health care services utilization and expenditures among low-income adult patients with asthma aged 26-64. Methods: Using a pooled dataset from 2007 to 2018 Medical Expenditures Panel Surveys (MEPS), we implemented a multivariate difference-in-differences analysis, which compared changes in utilization and expenditures for asthma-related health care services among adult patients with asthma with income below 133% Federal Poverty Level (FPL) vs. above 133%-400% FPL, before and after Medicaid expansion in 2014. We used negative binomial models to analyze utilization outcomes. Expenditures were estimated using two-part models with logit as the first part and generalized linear models as the second part. Estimates were weighted for the complex multi-stage sampling design of MEPS. Results: Medicaid expansion was associated with increases in both utilization and expenditures for asthma-related prescription drugs among low-income patients with asthma, by 1.8 prescription fills (p < 0.05) and $233 (p < 0.05) per year, respectively. No statistically significant association was detected for other asthma-related health care services. Conclusion: Medicaid expansion led to an increase in accessibility of prescription drugs among low-income asthma patients, but had no effect on other asthma-related health care services.

PMID:34978935 | DOI:10.1080/02770903.2021.2025389

Am Nat. 2022 Jan;199(1):108-125. doi: 10.1086/717178. Epub 2021 Nov 22.

ABSTRACT

AbstractEfforts to explain animal population cycles often invoke consumer-resource theory, which has shown that consumer-resource interactions alone can drive population cycles. Eco-evo theory instead argues that population cycles are partly driven by fluctuating selection for resistance in the resource, but support for eco-evo theory has come almost entirely from laboratory microcosms. Here we ask, Can eco-evo theory explain population cycles in the field? We compared the ability of eco-evo models and classical “eco-only” models to explain data on cycles in the insect Lymantria dispar, in which outbreaks of the insect are terminated by a fatal baculovirus. We carried out a statistical comparison of the ability of eco-only and eco-evo models to explain combined data from L. dispar outbreak cycles and baculovirus epizootics (epidemics in animals). Both models require high host variation in resistance to explain the epizootic data, but high host variation in the eco-evo model leads to consistently accurate predictions of outbreak cycles, whereas in the presence of high host variation the eco-only model can explain outbreak cycles only by invoking high levels of stochasticity, which leads to highly variable and often inaccurate predictions of outbreak cycles. Our work provides statistically robust evidence that eco-evo models can explain population cycles in the field.

PMID:34978965 | DOI:10.1086/717178

Dent Med Probl. 2021 Dec 31. doi: 10.17219/dmp/135652. Online ahead of print.

ABSTRACT

OBJECTIVES: The aim of this study was to evaluate the SBS of pre-sintered and sintered zirconia to a selfadhesive resin cement after various treatment (air abrasion and the Nd:YAG laser irradiation at varying power levels -1 W, 2 W and 3 W).

MATERIAL AND METHODS: Ninety-nine zirconia specimens were prepared and divided into 3 groups: control (with no surface treatment); and pre-sintered and sintered groups with surface treatment. Surface treatment was applied before sintering in the pre-sintered group and after sintering in the sintered group. After following all protocols, a resin cement was layered on the zirconia surface. Shear bond strength was measured using a universal testing machine. The results were subjected to the statistical analysis. The surface topography and phase transformation of zirconia were evaluated using the atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses after surface treatment.

RESULTS: The laser irradiation (3 W, 1 W and 2 W) of the pre-sintered zirconia surface resulted in the highest SBS values (p < 0.001), while the lowest SBS values were obtained with airborne particle abrasion of the pre-sintered and sintered zirconia surfaces.

CONCLUSIONS: Laser irradiation increased the SBS of pre-sintered zirconia to a resin cement. Surface treatment with air abrasion had a lesser effect on the SBS values.

PMID:34978766 | DOI:10.17219/dmp/135652

Antimicrob Agents Chemother. 2022 Jan 3:AAC0182121. doi: 10.1128/AAC.01821-21. Online ahead of print.

ABSTRACT

The active metabolites of primaquine, in particular 5-hydroxyprimaquine, likely responsible for clearance of dormant hypnozoites, are produced through the hepatic CYP450 2D6 (CYP2D6) enzymatic pathway. With the inherent instability of 5-hydroxyprimaquine, a stable surrogate, 5,6 orthoquinone, can now be detected and measured in the urine as part of primaquine pharmacokinetic studies. This study performed CYP450 2D6 genotyping and primaquine pharmacokinetic testing, to include urine 5,6 orthoquinone, in 27 healthy adult Cambodians, as a preliminary step to prepare for future clinical studies assessing primaquine efficacy for Plasmodium vivax infections. The CYP2D6 *10 reduced activity allele was found in 57% of volunteers, and the CYP2D6 genotypes were dominated by *1/*10 (33%) and *10/*10 (30%). Predicted phenotypes were evenly split between Normal Metabolizer (NM) and Intermediate Metabolizer (IM) except one volunteer with a gene duplication and unclear phenotype, classifying as either IM or NM. Median plasma PQ area under the curve (AUC) was lower in the NM group (460 hr*ng/mL) compared to the IM group (561 hr*ng/mL), although not statistically significant. Similar to what has been found in the US study, no 5,6 orthoquinone was detected in the plasma. The urine creatinine-corrected 5,6 orthoquinone AUC in the NM group was almost three times higher than in the IM group, with peak measurements (T_max) at 4 hours. Although there is variation among individuals, future studies examining the relationship between the levels of urine 5,6 orthoquinone and primaquine radical cure efficacy could result in a metabolism biomarker predictive of radical cure.

PMID:34978892 | DOI:10.1128/AAC.01821-21

Trop Med Int Health. 2022 Jan 3. doi: 10.1111/tmi.13716. Online ahead of print.

ABSTRACT

OBJECTIVES: To describe the effect of adaptations to a person-centred care with short oral regimens on retention in care for rifampicin-resistant TB (RR-TB) in Kandahar province, Afghanistan.

METHODS: The study included people with RR-TB registered in the programme between 01 October 2016 and 18 April 2021. From 19 November 2019 the programme implemented a trial investigating the safety and effectiveness of short oral RR-TB regimens. During the trial, person-centred care was adapted. We included data from people living with RR-TB treated in the period before and after the care model was adapted and applied Kaplan-Meier statistics to compare rates of retention in care.

RESULTS: Of 236 patients registered in the RR-TB programme, 146 (61.9%) were registered before and 90 (38.1%) after the model of care was adapted. Before adaptations enhancing person-centred care, pre-treatment attrition was 23.3% (n=34/146), while under the adapted care model it was 5.6% (n=5/90). Attrition on treatment was 22.3% (n=25/112) before adaptations, while during the study period none of the participants were lost to follow-up on treatment and 3.3% died (n=3/90).

CONCLUSIONS: As person-centred care delivery and treatment regimens were adapted to better fit specific contextual challenges and the needs of the target population, retention in care improved among people with RR-TB in Kandahar, Afghanistan.

PMID:34978748 | DOI:10.1111/tmi.13716

Neth Heart J. 2022 Jan 3. doi: 10.1007/s12471-021-01650-y. Online ahead of print.

ABSTRACT

In the Netherlands, the coronavirus disease 2019 (COVID‑19) pandemic has resulted in excess mortality nationwide. Chronic heart disease patients are at risk for a complicated COVID‑19 course. The current study investigates all-cause mortality among cardiac implantable electronic device (CIED) patients during the first peak of the pandemic and compares the data to the statistics for the corresponding period in the two previous years. Data of adult CIED patients undergoing follow-up at the Leiden University Medical Centre were analysed. All-cause mortality between 1 March and 31 May 2020 was evaluated and compared to the data for the same period in 2019 and 2018. At the beginning of the first peak of the pandemic, 3,171 CIED patients (median age 70 years; 68% male; 41% ischaemic aetiology) were alive. Baseline characteristics of the 2019 (n = 3,216) and 2018 (n = 3,169) cohorts were comparable. All-cause mortality during the peak of the pandemic was 1.4% compared to 1.6% and 1.4% in the same period in 2019 and 2018, respectively (p = 0.84). During the first peak of the COVID‑19 pandemic, there was no substantial excess mortality among CIED patients in the Leiden area, despite the fact that this is group at high risk for a complicated course of a COVID‑19 infection. Strict adherence to the preventive measures may have prevented substantial excess mortality in these vulnerable patients.

PMID:34978678 | DOI:10.1007/s12471-021-01650-y