Effects of concentration of sodium hypochlorite as an endodontic irrigant on the mechanical and structural properties of root dentine: A laboratory study

alexandrossfakianakis shared this article with you from Inoreader Effects of concentration of sodium hypochlorite as an endodontic irrigant on the mechanical and structural properties of root dentine: A laboratory study via International Endodontic Journal Abstract Aim The use of high-concentration sodium hypochlorite (NaOCl) as an endodontic irrigant remains controversial because of its potential impact on the fracture strength of endodontically-treated teeth. This study evaluated the effects of using different NaOCl concentrations, with 2-min-ethylenediaminetetraacetic acid (EDTA) as the final active irrigant, on the biomechanical and structural properties of root dentine. Methodology A new test method, which is more clinically relevant, was utilized to calculate the fracture strength of root dentine. Bovine incisors were used to obtain root dentine discs. The root canals were enlarged to mean diameter of 2.90 mm with a taper of 0.06. The resulting discs were divided into 5 groups (n=20) and treated with different concentrations of NaOCl (5.25%, 2.5%, and 1.3%) for 30 min plus 17% EDTA for 2 min. The discs were then loaded to fracture by a steel rod with the same taper through the central hole. The fractured specimens were examined by scanning electron microscopy to evaluate changes in the dimensions of the remaining intertubular dentine and the tubular radius. Micro-hardness was also measured with a Knoop diamond indenter along a radius to determine the depth of dentine eroded by the irrigation. Results were analyzed by one-way ANOVA and the Tukey test. The level of significance was set at α = 0.05. Results The damage by NaOCl increased with its concentration. 5.25% NaOCl greatly reduced the fracture strength of root dentine from 172.10±30.13 MPa to 114.58±26.74 MPa. The corresponding reduction in micro-hardness at the root canal wall was 34.1%. The damages reached a depth of up to 400 μm (p < 0.05). Structural changes involved degradation of the intratubular wall leading to enlarged dentinal tubules and the loss of intertubular dentine. Changes in the microstructural parameters showed positive linear relationships with the fracture strength. Conclusions With the adjunctive use of EDTA, NaOCl caused destruction to the intratubular surface near the root canal and, consequently, reduced the root dentine's mechanical strength. The higher the concentration of NaOCl, the greater the effect. Therefore, endodontists should avoid using overly high concentration of NaOCl for irrigation to prevent potential root fracture in endodontically-treated teeth. View on Web

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Response to a novel, weight self‐awareness plan used in a multi‐component lifestyle intervention programme to reduce breast cancer risk factors in older women – secondary analysis from The ActWELL trial

alexandrossfakianakis shared this article with you from Inoreader Response to a novel, weight self‐awareness plan used in a multi‐component lifestyle intervention programme to reduce breast cancer risk factors in older women – secondary analysis from The ActWELL trial via Journal of Human Nutrition and Dietetics Abstract Background The ActWELL RCT assessed the effectiveness of a weight management programme delivered by volunteer lifestyle coaches (LC) in women attending breast clinics. The intervention focused on caloric intake and physical activity, utilising behavioural change techniques including a weight awareness plan (WAP). The current work is a secondary analysis of the ActWELL data and aims to examine the response to the weight self-awareness plan (used as part of the intervention programme). Methodology The LCs invited participants (n=279) to undertake an implementation intention discussion to formulate a self-weighing (SW) plan. Bodyweight scales were offered, and recording books provided. The PA intervention focused on a walking plan assessed by accelerometers. The LCs contacted participants by telephone monthly and provided personalised feedback. Mann-Whitney tests and chi-squared analysis were used to examine the effect of SW on weight change. A qualitative evaluation utilising semi-structured interviews was also undertaken. Results Most participants (96.4%) agreed to set a weekly SW goal and 76 (27%) requested scales. At 12 months, 226 (81%) returned for follow up. The median (IQR) weight change for those who self- reported at least one weight (n=211) was -2.3kg (-5.0, 0.0) compared to -1.2kg (-5.0, 0.03) in those who did not (n=14). Participants who reported weights on >8 occasions (39%) were significantly more likely (p=0.012) to achieve 5% weight loss compared to those who weighed less often. Low numbers of accelerometers were returned which did not allow for significance testing. Qualitative data (n=24) indicated that many participants found the WAP helpful and motivating. Principal Conclusion Greater adherence to the WAP initiated by volunteer coaches is associated with achieving 5% weight loss. This article is protected by copyright. All rights reserved. View on Web

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Interpretation of Mendelian randomization using a single measure of an exposure that varies over time

alexandrossfakianakis shared this article with you from Inoreader Interpretation of Mendelian randomization using a single measure of an exposure that varies over time via International Journal of Epidemiology - Advance Access Abstract BackgroundMendelian randomization (MR) is a powerful tool through which the causal effects of modifiable exposures on outcomes can be estimated from observational data. Most exposures vary throughout the life course, but MR is commonly applied to one measurement of an exposure (e.g. weight measured once between ages 40 and 60 years). It has been argued that MR provides biased causal effect estimates when applied to one measure of an exposure that varies over time. Methods We propose an approach that emphasizes the liability that causes the entire exposure trajectory. We demonstrate this approach using simulations and an applied example. Results We show that rather than estimating the direct or total causal effect of changing the exposure value at a given time, MR estimates the causal effect of changing the underlying liability for the exposure, scaled to the effect of the liability on the exposure at that time. As such, results from MR conducted at different time points are expected to differ (unless the effect of the liability on exposure is constant over time), as we illustrate by estimating the effect of body mass index measured at different ages on systolic blood pressure. Conclusion Univariable MR results should not be interpreted as time-point-specific direct or total causal effects, but as the effect of changing the liability for the exposure. Estimates of how the effects of a genetic variant on an exposure vary over time, together with biological knowledge that provides evidence regarding likely effective exposure periods, are required to interpret time-point-specific causal effects. View on Web

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Toll‐like receptor‐1, ‐2, and ‐6 genotypes in relation to salivary human beta‐defensin‐1, ‐2, ‐3 and human neutrophilic peptide‐1

alexandrossfakianakis shared this article with you from Inoreader Toll‐like receptor‐1, ‐2, and ‐6 genotypes in relation to salivary human beta‐defensin‐1, ‐2, ‐3 and human neutrophilic peptide‐1 via Journal of Clinical Periodontology Abstract Aim To examine whether functional gene polymorphisms of toll-like receptor (TLR)1, TLR2, and TLR6 are related to the salivary concentrations of human beta-defensins (hBDs)-1, -2, -3, and human neutrophilic peptide (HNP)-1. Materials and methods Polymorphisms of TLR1 (rs5743618), TLR2 (rs5743708), and TLR6 (rs5743810) were genotyped by PCR-based pyrosequencing from the salivary samples of 230 adults. Salivary hBD-1, -2, -3, and HNP-1 concentrations were measured using ELISA. General and periodontal health examination, including panoramic radiography, were available for all participants. Results The genotype frequencies for wild types and variant types were as follows: 66.5% and 33.5% for TLR1, 95.5% and 4.5% for TLR2, and 25.1% and 74.9% for TLR6, respectively. The TLR2 heterozygote variant group exhibited higher salivary hBD-2 concentrations than the TLR2 wild type group (p=0.038). On the contrary, elevated hBD-2 concentrations were detected in the TLR6 wild type group compared to the TLR6 heterozygote & homozygote variant group (p=0.028). The associations between TLR6 genotypes and salivary hBD-2 concentrations remained significant after adjusting them for periodontal status, age, and smoking. Conclusion hBD-2 concentrations in saliva are related to TLR2 and TLR6 polymorphisms, but only the TLR6 genotype seems to exhibit an independent association with the salivary hBD-2 concentrations. This article is protected by copyright. All rights reserved. View on Web

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Anterior implant restorations with a convex emergence profile increase the frequency of recession: 12‐month results of a randomized controlled clinical trial

alexandrossfakianakis shared this article with you from Inoreader Anterior implant restorations with a convex emergence profile increase the frequency of recession: 12‐month results of a randomized controlled clinical trial via Journal of Clinical Periodontology Abstract Objectives To test whether or not the emergence profile (CONVEX or CONCAVE) of implant-supported crowns influences the mucosal margin stability up to 12 months post insertion of the final restoration. Materials and methods Forty-seven patients with a single implant in the anterior region were randomly allocated to one of three groups:1) CONVEX (n=15), implant provisional and an implant-supported crown both with a convex profile; 2) CONCAVE (n=16), implant provisional and an implant-supported crown both with a concave profile; 3) CONTROL (n=16), no provisional (healing abutment only) and an implant-supported crown. All patients were recalled at baseline, 6 and 12 months. The stability of mucosal margin along with clinical, aesthetic, profilometric outcomes as well as time and costs were evaluated. To predict the presence of recession multivariable logistic regressions were performed and linear models using generalized estimation equations (GEE) were conducted for the different outcomes. Results Forty-four patients were available at 12 months post-loading. The frequency of mucosal recession amounted to 64.3% in group CONVEX, 14.3% in group CONCAVE and 31.4% in group CONTROL. Regression models revealed that a CONVEX profile was significantly associated with the presence of recessions (OR:12.6, CI:95%: 1.82-88.48, p=0.01) compared to the CONCAVE profile. Pink aesthetic scores amounted to 5.9 in group CONVEX, 6.2 in group CONCAVE and 5.4 in group CONTROL, with no significant differences between the groups (p=0.756). Groups CONVEX and CONCAVE increased the appointments and costs compared to the CONTROL group. Conclusion The use of implant-supported provisionals with a CONCAVE emergence profile results in a greater stability of the mucosal margin compared to a CONVEX profile up to 12 months of loading. This is accompanied, however, by increased time and costs compared to the absence of a provisional and may not necessarily enhance the aesthetic outcomes. This article is protected by copyright. All rights reserved. View on Web

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Autogenous Bone Block versus Collagenated Xenogeneic Bone Block in the reconstruction of the atrophic alveolar ridge: a non‐inferiority randomized clinical trial

alexandrossfakianakis shared this article with you from Inoreader Autogenous Bone Block versus Collagenated Xenogeneic Bone Block in the reconstruction of the atrophic alveolar ridge: a non‐inferiority randomized clinical trial via Journal of Clinical Periodontology Abstract Objective To compare the efficacy of equine derived collagenated bone blocks (CXBB) and autogenous bone block (ABB) for lateral alveolar ridge augmentation and two-stage implant placement. Materials and methods Sixty-four patients with tooth gaps up to 4 teeth and atrophic alveolar ridges with ≤ 4 mm were randomly assigned to lateral augmentation using CXBB or ABB. Lateral bone thickness was measured 2 mm below the alveolar crest at augmentation surgery and 30 weeks later at implant placement. Implant related outcomes, adverse events, surgery duration, pain sensation, analgesic consumption and oral health-related quality of life were also assessed. Data was analyzed using Fisher's exact, Mann–Whitney, and Wilcoxon signed-rank tests. Results At 30 weeks, the median change in lateral bone thickness amounted to 2.90 (CXBB) and 3.00 (ABB), respectively. Secondary endpoints demonstrated similar results for CXBB and ABB in terms of possibility to place an implant, need to perform a secondary bone augmentation at implant placement and rate of complications. Early implant failure was 20% for CXBB and 10% for ABB, with no difference between the groups. Pain scores and postoperative consumption of analgesics were significantly lower in the CXBB group than in the ABB group, especially during the first days post-surgery. Conclusion CXBB is non-inferior to ABB for horizontal alveolar ridge augmentation and two-stage implant placement. This article is protected by copyright. All rights reserved. View on Web

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Offset analgesia is increased intra‐orally

alexandrossfakianakis shared this article with you from Inoreader Offset analgesia is increased intra‐orally via Journal of Oral Rehabilitation Abstract Background Offset analgesia (OA) is commonly used to quantify endogenous pain inhibition. However, the potential role of afferent inputs and the subsequent peripheral factors from different body areas on the underlying mechanisms are still unclear. Objectives The aim of this cross-sectional study was to compare the magnitude of OA in four different body areas representing a) glabrous and non-glabrous skin, b) trigeminal and extra-trigeminal areas, and c) intra- and extra-oral tissue. Methods OA was assessed at the oral mucosa of the lower lip, at the skin of the cheek, the forearm and the palm of the hand in 32 healthy and pain-free participants. OA testing included two trials: (1) a constant trial (30 seconds of constant heat stimulation at an individualized temperature of Pain50 (pain intensity of 50 out of 100)), and (2) an offset trial (10 seconds of individualized Pain50, followed by 5 seconds at Pain50+1°C and 15 seconds at Pain50). Participants continuously rated their pain during each trial with a computerized visual analog scale. Results A significant OA response was recorded at the oral mucosa (p<0.001, d=1.24), the cheek (p<0.001, d=0.84) and the forearm (p<0.001, d=1.04), but not at the palm (p=0.19, d=0.24). Significant differences were shown for OA recorded at the cheek versus the mucosa (p=0.02), and between palm and mucosa (p=0.007), but not between the remaining areas (p>0.05). Conclusion This study suggests that intra-oral endogenous pain inhibition assessed with OA is enhanced and supports the role of peripheral mechanisms contributing to the OA response. View on Web

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