Tag: nevin manimala

J Contemp Dent Pract. 2020 Nov 1;21(11):1201-1204.

ABSTRACT

AIM: This study aims to evaluate the difference in fracture resistance of the short fiber-reinforced composite (SFRC) thickness as intermediate layer of class II composite restoration.

MATERIALS AND METHODS: Thirty human maxillary premolars were selected and divided into three groups. In groups I, II, and III, class II cavities were prepared. Groups I and II were restored with 2 mm and 4 mm thickness of SRFC as intermediate layer. Group III as control group was restored with nanohybrid composite. Thermocycling procedure was performed manually 250 times. Fracture resistance was measured by using Universal Testing Machine. Data were analyzed statistically using One-way Analysis of Variance (ANOVA) and post hoc least significant difference (LSD) test.

RESULTS: The result showed that group II had the highest fracture resistance and group III had the lowest fracture resistance. The difference between groups was statistically significant (p value < 0.05).

CONCLUSION: The conclusion showed that adding 4 mm of SFRC as an intermediate layer increased the fracture resistance.

CLINICAL SIGNIFICANCE: The use of SFRC as intermediate layer enhanced the fracture resistance of class II composite restoration.

PMID:33850063

J Contemp Dent Pract. 2020 Nov 1;21(11):1233-1237.

ABSTRACT

AIM AND OBJECTIVE: The present study aimed to assess the formation of microcracks in root dentin post-instrumentation with nickel-titanium (NiTi) hand and rotary file system.

MATERIALS AND METHODS: Totally, 80 freshly extracted mandibular premolar teeth with single roots were chosen for this study. Access opening was performed and #10 K-file was used to attain patency of canal. All specimens were divided into four groups (each group having 20 specimens), i.e., Group I: Unprepared, Group II: NiTi hand K-files, Group III: Self-adjusting file, and Group IV: XP-Shaper single file. Complete irrigation of all the canals was performed after instrumentation. All roots were cut horizontally at three levels [apical third (3 mm), middle third (6 mm), and cervical third (9 mm)] from the apex with diamond disc. A stereomicroscope was used to view the sections under 20× magnification.

RESULTS: Self-adjusting file showed least number of defects with a percentage of 75% followed by XP-Shaper and NiTi hand K-files with a values of 65 and 60%, respectively. Use of hand K-files resulted in greater number of incomplete cracks (30%) and use of XP-Shaper demonstrated greater number of craze lines (15%). A statistically significant difference was found between the experimental groups in the formation of dentinal defects of root at apical third (3 mm) (p < 0.031) and middle third (6 mm) (p < 0.001), whereas the sections at cervical third (9 mm) did not show any statistically significant difference (p > 0.312).

CONCLUSION: The present study concluded that the self-adjusting file system gives promising better results in cleaning ability with minimal incidence of radicular dentin microcracks than XP-Shaper and NiTi hand K-files system.

CLINICAL SIGNIFICANCE: The root dentin may unavoidably get damaged during instrumentation resulting in the formation of dentinal cracks and tiny complicated fractures, thus leading to endodontic failures. Various factors cause dentinal cracks, but the flexibility of file due to heat treatment, kinematics of the file, and the basic architecture of the file are the most significant ones. Self-adjusting file system represented satisfactory results with minimal microcracks defects.

PMID:33850068

J Contemp Dent Pract. 2020 Nov 1;21(11):1253-1257.

ABSTRACT

AIM AND OBJECTIVE: In the present study, the prepared roots obturated by gutta-percha/AH plus and Resilon/Epiphany were tested and compared for fracture resistance. The study also does a scanning electron microscope (SEM) evaluation of the adaptability of these obturating materials to root canal walls.

MATERIALS AND METHODS: One hundred extracted mandibular premolars were decoronated and the dimensions of the roots were standardized. Each root was prepared to a size of #25 with 6% taper. Roots were gauged after preparation and those requiring more preparation were discarded. Seventy-seven prepared roots were finally selected for the study. The samples were then divided into three groups. Group I with 25 specimens was control group in which no obturation was performed, group II with 26 specimens was obturated by gutta-percha/AH plus sealer, and group III with 26 specimens was filled by Resilon/Epiphany. The method for obturation was cold lateral condensation. The samples were then stored at 100% humidity for 2 weeks. One random sample from groups II and III was subjected to SEM analysis. Groups I, II, and III were then subjected to vertical loading in Instron machine. One-way analysis of variance (ANOVA) test and Tukey’s multiple comparison test were used for statistical analysis.

RESULTS: Group III exhibited the maximum fracture resistance as compared to groups I and II. The least mean fracture resistance of 370.05 N was seen in group II and the maximum mean fracture resistance of 481.05 kN was observed in group III. One-way ANOVA and Tukey’s multiple comparison test between groups I, II, and III, group III showed a highly significant resistance to fracture as compared to groups I and II (p < 0.0001). Scanning electron microscope microphotographs showed a better adaptation of Resilon/Epiphany as compared to gutta-percha/AH plus to the root canal.

CONCLUSION: The Resilon/Epiphany on obturation of root canals creates a monoblock by penetrating inside the dentinal irregularities, which strengthens the root and provides fracture resistance. This fracture resistance was significantly higher in the present study as compared to groups I and II.

CLINICAL SIGNIFICANCE: In the present study, Resilon/Epiphany when used to obturate the prepared canals showed a promising result both in terms of fracture resistance and adaptability to root canal walls. This paves a way for the use of this combination of obturating material not only to strengthen the compromised root strength in clinical scenario but also providing an increased sealing ability which will contribute to the success of root canal treatment.

PMID:33850071

J Neurol Neurosurg Psychiatry. 2021 Apr 13:jnnp-2020-325141. doi: 10.1136/jnnp-2020-325141. Online ahead of print.

ABSTRACT

OBJECTIVE: To describe decline in muscle strength and physical function in patients with sporadic inclusion body myositis (IBM).

METHODS: Manual muscle testing (MMT), quantitative muscle testing (QMT) and disability scoring using the IBM Functional Rating Scale (IBMFRS) were undertaken for 181 patients for up to 7.3 years. The relationship between MMT, QMT and IBMFRS composite scores and time from onset were examined using linear mixed effects models adjusted for gender and age of disease onset. Adaptive LASSO regression analysis was used to identify muscle groups that best predicted the time elapsed from onset. Cox proportional hazards regression was used to evaluate time to use of a mobility aid.

RESULTS: Multilevel modelling of change in percentage MMT, QMT and IBMFRS score over time yielded an average decline of 3.7% (95% CI 3.1% to 4.3%), 3.8% (95% CI 2.7% to 4.9%) and 6.3% (95% CI 5.5% to 7.2%) per year, respectively. The decline, however, was not linear, with steeper decline in the initial years. Older age of onset was associated with a more rapid IBMFRS decline (p=0.007), but did not influence the rate of MMT/QMT decline. Combination of selected muscle groups allowed for generation of single measures of patient progress (MMT and QMT factors). Median (IQR) time to using a mobility aid was 5.4 (3.6-9.2) years, significantly affected by greater age of onset (HR 1.06, 95% CI 1.04 to 1.09, p<0.001).

CONCLUSION: This prospective observational study represents the largest IBM cohort to date. Measures of patient progress evaluated in this study accurately predict disease progression in a reliable and useful way to be used in trial design.

PMID:33849999 | DOI:10.1136/jnnp-2020-325141

Proc Natl Acad Sci U S A. 2021 Apr 20;118(16):e2015188118. doi: 10.1073/pnas.2015188118.

ABSTRACT

Many social and biological systems are characterized by enduring hierarchies, including those organized around prestige in academia, dominance in animal groups, and desirability in online dating. Despite their ubiquity, the general mechanisms that explain the creation and endurance of such hierarchies are not well understood. We introduce a generative model for the dynamics of hierarchies using time-varying networks, in which new links are formed based on the preferences of nodes in the current network and old links are forgotten over time. The model produces a range of hierarchical structures, ranging from egalitarianism to bistable hierarchies, and we derive critical points that separate these regimes in the limit of long system memory. Importantly, our model supports statistical inference, allowing for a principled comparison of generative mechanisms using data. We apply the model to study hierarchical structures in empirical data on hiring patterns among mathematicians, dominance relations among parakeets, and friendships among members of a fraternity, observing several persistent patterns as well as interpretable differences in the generative mechanisms favored by each. Our work contributes to the growing literature on statistically grounded models of time-varying networks.

PMID:33850012 | DOI:10.1073/pnas.2015188118

Proc Natl Acad Sci U S A. 2021 Apr 27;118(17):e2100365118. doi: 10.1073/pnas.2100365118.

NO ABSTRACT

PMID:33850050 | DOI:10.1073/pnas.2100365118

Ann Rheum Dis. 2021 Apr 13:annrheumdis-2021-220142. doi: 10.1136/annrheumdis-2021-220142. Online ahead of print.

NO ABSTRACT

PMID:33849919 | DOI:10.1136/annrheumdis-2021-220142

J Immunother Cancer. 2021 Apr;9(4):e002501. doi: 10.1136/jitc-2021-002501.

ABSTRACT

BACKGROUND: Immune checkpoint inhibitors (ICIs) are the new standard of care in microsatellite instability-high (MSI-H)/deficient mismatch repair (dMMR) metastatic colorectal cancer (mCRC). Since tumor response dynamic parameters already shown a strong association with survival outcomes in patients with mCRC treated with first-line therapy, we investigated the association of early tumor shrinkage (ETS) and depth of response (DoR) in patients with MSI-H/dMMR mCRC treated with ICIs.

METHODS: This is a retrospective, multicenter, cohort study in patients with dMMR and/or MSI-high mCRC treated with ICIs (anti-PD-1/PD-L1 with or without anti-CTLA-4 agents) with measurable disease and at least one post-baseline radiological disease reassessment. The Kaplan-Meier method and Cox proportional-hazards regression models were used for survival analyses. A maximally selected statistics method in a Cox regression model for progression-free survival (PFS) was used to determine the optimal cut-offs for ETS and DoR.

RESULTS: We included a total of 169 patients: 116 (68.6%) were treated with anti-PD-1 monotherapy, whereas 53 (31.4%) with anti-PD-1 plus anti-CTLA-4 agents. Patients with primary progressive disease (N=37, 21.9%), experienced an extremely poor overall survival (OS) and were evaluated separately. In patients with clinical benefit, we observed a significant association between ETS and DoR with both OS and PFS, and we identified a relative reduction of at least 1% as the optimal cut-off for ETS and a relative reduction of at least 50% as the optimal cut-off for DoR.

CONCLUSIONS: ETS and DoR are important prognostic factors in patients with MSI-high mCRC treated with ICIs that might be useful to design treatment intensification/deintensification strategies. A prospective validation of both is warranted.

PMID:33849927 | DOI:10.1136/jitc-2021-002501

Hosp Pediatr. 2021 Apr 13:hpeds.2020-001636. doi: 10.1542/hpeds.2020-001636. Online ahead of print.

ABSTRACT

BACKGROUND: Penicillin allergy is reported in up to 10% of the general population; however, >90% of patients reporting an allergy are tolerant. Patients labeled as penicillin allergic have longer hospital stays, increased exposure to suboptimal antibiotics, and an increased risk of methicillin-resistant Staphylococcus aureus and Clostridioides difficile. The primary aim with our quality improvement initiative was to increase penicillin allergy delabeling to at least 10% among all hospitalized pediatric patients reporting a penicillin allergy with efforts directed toward patients determined to be low risk for true allergic reaction.

METHODS: Our quality improvement project included several interventions: the development of a multidisciplinary clinical care pathway to identify eligible patients, workflow optimization to support delabeling, an educational intervention, and participation in our institution’s quality improvement incentive program. Our interventions were targeted to facilitate appropriate delabeling by the primary hospital medicine team. Statistical process control charts were used to assess the impact of this intervention pre- and postpathway implementation.

RESULTS: After implementation of the clinical pathway, the percentage of patients admitted to hospital medicine delabeled of their penicillin allergy by discharge increased to 11.7%. More than one-half of those delabeled (51.2%) received a penicillin-based antimicrobial at time of discharge. There have been no adverse events or allergic reactions requiring emergency medication administration since pathway implementation.

CONCLUSIONS: Our quality improvement initiative successfully increased the rate of penicillin allergy delabeling among low-risk hospitalized pediatric patients, allowing for increased use of optimal antibiotics.

PMID:33849960 | DOI:10.1542/hpeds.2020-001636

BMJ Open. 2021 Apr 13;11(4):e044949. doi: 10.1136/bmjopen-2020-044949.

ABSTRACT

INTRODUCTION: Surgical interventions can elicit neuroendocrine responses and sympathovagal imbalance, ultimately affecting cardiac autonomic function. Cardiac complications account for 30% of postoperative complications and are the leading cause of morbidity and mortality following non-cardiac surgery. One cardiovascular parameter, heart rate variability (HRV), has been found to be predictive of postoperative morbidity and mortality. HRV is defined as variation in time intervals between heartbeats and is affected by cardiac autonomic balance. Furthermore, altered HRV has been shown to predict cardiovascular events in non-surgical settings. In multiple studies, experimentally induced pain in healthy humans leads to reduced HRV suggesting a causal relationship. In a different studies, chronic pain has been associated with altered HRV, however, in the setting of clinical pain conditions, it remains unclear how much HRV impairment is due to pain itself versus autonomic changes related to analgesia. We aim to review the available evidence describing the association between postsurgical pain and HRV alterations in the early postoperative period.

METHODS AND ANALYSIS: We will conduct a scoping review of relevant studies using detailed searches of MEDLINE and EMBASE, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Included studies will involve participants undergoing non-cardiac surgery and investigate outcomes of (1) measures of pain intensity; (2) measures of HRV and (3) statistical assessment of association between #1 and #2. As secondary review outcomes included studies will also be examined for other cardiovascular events and for their attempts to control for analgesic treatment and presurgical HRV differences among treatment groups in the analysis. This work aims to synthesise available evidence to inform future research questions related to postsurgical pain and cardiac complications.

ETHICS AND DISSEMINATION: Ethics review and approval is not required for this review. The results will be submitted for publication in peer-reviewed journals.

PMID:33849852 | DOI:10.1136/bmjopen-2020-044949