Tag: nevin manimala

Oper Dent. 2022 Jan 3. doi: 10.2341/20-270-L. Online ahead of print.

ABSTRACT

OBJECTIVES: This study aimed to investigate the effects of hydrothermal treatment on four types of monolithic, translucent, yttria-stabilized, tetragonal zirconia polycrystals (Y-TZPs).

METHODS AND MATERIALS: Two commercially available Y-TZP brands-SuperfectZir High Translucency (Aidite Technology Co, China) and Katana HT (Kuraray Noritake Dental, Japan) were assessed. For each brand of Y-TZP, materials of four coloring types, including noncolored (NC), colored by staining (CS), precolored (PC), and multilayered (ML) specimens were investigated after hydrothermal aging in an autoclave at 134°C/0.2 MPa for 0 (control group), 5, 10, and 20 hours. The tetragonal-to-monoclinic phase transformation, surface roughness, flexural strength, and structural reliability (Weibull analysis) were measured and statistically analyzed (α=0.05). The subsurface microstructure was analyzed with scanning electron microscopy.

RESULTS: The group ML exhibited the lowest flexural strength and Weibull characteristic strength among the four coloring types (p<0.05). Slight increases in the monoclinic phase volume, flexural strength, and Weibull characteristic strength were observed after hydrothermal aging (pall<0.05). Regardless of coloring type, no significant effects of aging on the Weibull modulus or surface roughness were found for the tested materials. Compared with the Katana HT cross-sections, the SuperfectZir High Translucency cross-sections exhibited a similar but thicker transformation zone.

CONCLUSIONS: The coloring procedure and material type were found to affect the mechanical properties and aging resistance of translucent monolithic Y-TZP ceramics. Regardless of the aging time, the surface roughness of the tested Y-TZP ceramics remained unchanged.

PMID:34979031 | DOI:10.2341/20-270-L

Int J Pharm Pract. 2022 Jan 3:riab083. doi: 10.1093/ijpp/riab083. Online ahead of print.

ABSTRACT

OBJECTIVES: Literature assessing the optimal means of providing academic advisement in pharmacy education is limited. The objective of this study was to describe students’ perception of advising within a school of pharmacy.

METHODS: A 27-question survey was developed utilizing Qualtrics and sent to all students at one school of pharmacy. Baseline descriptive data regarding frequency and format of meeting with the assigned advisor were collected, as well as students’ opinions of these meetings.

KEY FINDINGS: Of 282 students who were sent the survey, 90 responded (31.9%). The majority of students preferred to meet with their faculty advisor in a group as compared with one-on-one (59 versus 29, 67%). Most students found the advisor/advisee relationship beneficial (n = 77, 85%).

CONCLUSIONS: There was no statistically significant difference in student perception of the quality or value of advisor/advisee meetings between students who met in a group or one-on-one with their advisors.

PMID:34979023 | DOI:10.1093/ijpp/riab083

Oper Dent. 2022 Jan 3. doi: 10.2341/20-236-C. Online ahead of print.

ABSTRACT

This study aimed to evaluate the effect of the bleaching gel application site on chromatic changes and postoperative sensitivity in teeth. Thirty patients were selected and allocated to three groups (n=10 per group), according to the location of the gel: GI, cervical application; GII, incisal application; and GIII, total facial. The amount and time of application of the 35% hydrogen peroxide (H2O2) gel were standardized. Color changes were analyzed by ΔE and Wid (bleaching index), using the values obtained in the readings conducted on a digital spectrophotometer in the cervical (CRs) and incisal regions (IRs) of the teeth. Spontaneous sensitivity was assessed using the questionnaire, and the stimulated sensitivity caused by the thermosensory analysis (TSA). The analysis occurred in five stages: baseline, after the first, second, and third whitening sessions (S), and 14 days after the end of the whitening, using the linear regression statistical model with mixed effects and post-test by orthogonal contrasts (p<0.05). Although the IR was momentarily favored, at the end of the treatment, the restriction of the application site provided results similar to those obtained when the gel was applied over the entire facial surface. Regarding sensitivity, only the GI showed spontaneous sensitivity. In the TSA, GIII had less influence on the threshold of the thermal sensation. It was concluded that the chromatic alteration does not depend on the gel application site. Spontaneous sensitivity is greater when the gel is concentrated in the cervical region (CR), and the teeth remain sensitized by thermal stimuli even after 14 days.

PMID:34979026 | DOI:10.2341/20-236-C

Gen Dent. 2022 Jan-Feb;70(1):72-77.

ABSTRACT

This study evaluated the quantity of metal artifacts produced by dental implants placed in different mandibular regions using various cone beam computed tomography (CBCT) protocols. Titanium implants were placed in 4 regions (incisor, canine, premolar, and molar) of an artificial mandible and subjected to CBCT examinations with the mandibular model placed in different positions within the field of view (FOV) and imaged with different FOV and voxel sizes. An axial section of the cervical region of each implant was selected for artifact quantification. The artifacts were measured by normalizing the actual standard deviation (ASD) of the voxel values. Kruskal-Wallis and Student-Newman-Keuls tests were used to compare the tooth regions and the different positions of the mandible. The Wilcoxon test was used to compare changes in FOV and voxel size. The intraobserver agreement was calculated using the intraclass correlation coefficient. The significance level was 5%. The incisor region showed significantly more artifacts than other regions (P = 0.0315). No statistically significant difference was found when the position of the mandible varied within the FOV (P = 0.7418). Smaller FOV and smaller voxels produced more artifacts (P < 0.0001). The quantity of metal artifacts was affected by FOV and voxel size as well as by anatomical region. Variation of the mandible location within the FOV did not affect the artifacts as defined by the normalized ASD of the voxel values.

PMID:34978995

Gen Dent. 2022 Jan-Feb;70(1):51-55.

ABSTRACT

The objectives of the present study were to compare measurements of pharyngeal airway subregions on lateral cephalometric (LC) and cone beam computed tomographic (CBCT) images in relation to skeletal classes and discuss the advantages and disadvantages of these imaging formats for this type of assessment. The CBCT images were assessed via both multiplanar reconstruction (MPR) and 3-dimensional (3D) reconstruction. The LC and CBCT images from 107 patients were classified according to skeletal class: I, n = 35; II, n = 35; and III, n = 37. Linear measurements of the subdivisions of the upper airway were performed on the LC, MPR, and 3D images. In addition, area and volumetric measurements were performed on the MPR images. The relationships among imaging methods, skeletal class, and pharyngeal thirds were assessed by means of a 1-way analysis of variance (α = 0.05). No statistically significant differences in the linear, area, or volumetric measurements of the upper airway subregions were found among the skeletal classes (P > 0.05). For the linear measurements in the oropharynx and hypopharynx, greater values were observed for the LC images than for the MPR and 3D images (P ≤ 0.05). Based on the study findings, MPR images should be preferred for visualization of the pharyngeal airway subregions. However, LC imaging is preferable to 3D reconstruction.

PMID:34978991

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