Dental plaque quantitation by light induced fluorescence technology in exclusive Electronic Nicotine Delivery Systems (ENDS) users.

OBJECTIVES: In comparison to conventional combustible cigarettes, Electronic Nicotine Delivery Systems (ENDS) including both e-cigarettes (ECs) and heated tobacco products (HTPs) significantly reduce exposure to toxic chemical emissions. However, their impact on dental plaque remains unclear. This study measures dental plaque in ENDS (ECs and HTPs) users using quantitative light-induced fluorescence (QLF) technology, comparing them with current, former, and never smokers. METHODS: This cross-sectional study compared dental plaque measurements using QLF technology (Q-ray cam™ Pro) among current smokers (≥10 cigarettes/day), former smokers (quit ≥6 months), never smokers, and exclusive ENDS users (quit ≥6 months). Dental plaque measurements were expressed as ΔR30 (total area of mature dental plaque) and ΔR120 (greater plaque thickness/maturation-calculus). The Simple Oral Hygiene (SOH) score was calculated by the QLF proprietary software. Statistical analyses including ANCOVA was performed by R version (4.2.3) with p < 0.05. RESULTS: A total 30 smokers, 24 former smokers, 29 never smokers, and 53 ENDS users were included. Current smokers had significantly higher ΔR30 and ΔR120 values compared to other groups (p < 0.001). ENDS users showed plaque levels similar to never and former smokers (p > 0.05) but significantly lower than current smokers (p < 0.01). Although ENDS users showed a lower SOH score than smokers, this difference was not statistically significant. Daily toothbrushing and mouthwash usage were significant covariates. CONCLUSION: ENDS users exhibited reduced accumulation of dental plaque and calculus compared with current smokers. CLINICAL SIGNIFICANCE: Exclusive ENDS use could less impact dental plaque accumulation compared to cigarette smoking. Further research is needed to confirm these findings and fully understand ENDS impact on dental plaque formation.

Advancements in guided surgical endodontics: A scoping review of case report and case series and research implications.

This scoping review examined current case series and reports on guided surgical endodontic applications in order to provide a critical platform for future research. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews guidelines were followed. A search on PubMed and Scopus yielded 611 articles, with 17 case reports and 1 series meeting inclusion criteria. Overall, guided surgery addressed anatomical complexities, with 15 articles employing static protocols and 3 dynamic. Results showed minimal iatrogenic errors and reduced chair time, with no postoperative issues reported. Within the cases described, guided endodontic surgery exhibited satisfactory results in management of anatomical complex cases. Cost-effectiveness, the need for adequate follow-up, procedure's reproducibility and accuracy, and objective measurement of the reduction in operative times and iatrogenic errors are some of the limitations in the current reports that need to be considered for planning of future experimental and cohort studies.

E-cigarettes and heated tobacco products impact on dental color parameters.

Objectives: Abstaining from tobacco smoking may not only improve general health, but also reduce teeth staining and restore teeth whiteness. Compared with conventional cigarettes, E-cigarettes (ECs) and heated tobacco products (HTPs) may offer substantial reduction in exposure to pigmented tar-like compounds of cigarette smoke. It is possible that improvements in dental color indices may be observed in those who have stopped smoking combustible cigarettes by switching to tar-free nicotine delivery products. Methods: This cross-sectional study evaluated and compared dental color parameters by digital spectrophotometry among five different groups: individuals who currently smoke ; individuals who used to smoke but have quit ; individuals who have never smoked ; exclusive users of electronic cigarettes (former smokers) ; and exclusive users of heated tobacco products (former smokers) . Results: Dental whiteness in current cigarette smokers was notably worse compared with never and former smokers, (13.38 Whiteness Index for Dentistry (WID) units vs. 19.96 and 16.79 WID units). Remarkably high WID values (i.e., whiter teeth) were also observed in ECs (16.72 WID units) and HTPs users (17.82 WID units). Compared to current smokers, difference in dental whiteness for ECs and HTPs users was visually noticeable (ΔWID difference being on average > 2.90 units). The colour differences measured as delta E*(ΔE*) were all visually detectable except for the comparison between ex-smokers and ECs users for which no perceptible color difference was observed (0.415). Conclusion: Exclusive use of ECs and HTPs is associated with better dental color measurements than current smoking, suggesting that tar-free nicotine delivery technologies are unlikely to have negative effects on dental appearance. Clinical significance: Use of alternative nicotine delivery systems may be associated with cosmetic benefits with important implications for those smokers perceiving dental aesthetics as a significant problem. For these an oral-based narrative may be a much more significant reason to refrain from smoking than the fear of developing smoking-related diseases in future.

Influence of quitting smoking on diabetes-related complications: A scoping review with a systematic search strategy.

INTRODUCTION: Smoking in people with diabetes markedly elevates their risk of developing complications and increases the likelihood of cardiovascular mortality. This review is the first to specifically provide evidence-based analysis about the influence of quitting smoking on diabetes-related complications in people with type 2 diabetes. METHOD: The present review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Extension for Scoping Reviews. All human clinical studies assessing the effects of stopping smoking cessation on diabetes-related complications were included. PubMed and Embase were screened until January 2024. References of primary studies and principal peer-reviewed scientific journals in the field were manually screened. RESULTS: We identified a total of 1023 studies. Only 26 met the criteria for eligibility. In general quitting smoking is associated with decreased risks of myocardial infarction and ischemic stroke. Regarding microvascular complications, the strongest evidence for the beneficial effects of smoking cessation is observed in diabetic nephropathy. However, the relationship between smoking cessation and retinopathy, neuropathy, diabetic foot complications and diabetic-related erectile dysfunction, is poorly investigated. CONCLUSION: Quitting smoking offers significant advantages in managing diabetes-related complications, significantly lowering the risks of myocardial infarction, ischemic stroke, and diabetic nephropathy. This underscores the importance of cessation. Providing evidence-based information on the benefits of stopping smoking for people with type 2 diabetes who smoke, can bolster smoking cessation efforts in the context of diabetes management.

Behavioral Therapy for People With Diabetes Who Smoke: A Scoping Review.

BACKGROUND: Tobacco smoking exacerbates diabetes-related complications; its prevalence is notwithstanding substantial. Persons with diabetes face a number of barriers and challenges to quitting such as multiple lifestyle restrictions; tailored interventions are required for smoking cessation. OBJECTIVE: To identify research on behavioral interventions for smoking cessation in diabetes. METHODS: Studies had to be randomized controlled trials, quasiexperimental or systematic reviews. The behavioral interventions included were: the 5As, Cognitive-Behavioral Therapy, Motivational Interviewing, Contingency Management, Health Coaching and Counselling, as compared to standard care. The outcomes were self-reported and/or biochemically verified smoking cessation. CINAHL Complete, MEDLINE Complete, the Cochrane databases of systematic reviews and randomized controlled trials, PsychInfo and PubMed Central were searched until July, 2023. Keywords used included diabetes, smoking cessation and each of the behavioral interventions included. RESULTS: 1615 papers were identified. Three studies on the 5As/brief advice, 4 on Motivational Intervention and 1 on counseling were retained. The results on the 5As and Motivational Interviewing were conflicting. More intensive interventions appear to be more successful in achieving smoking cessation in smokers with diabetes. CONCLUSIONS: Future research should focus on the continued development and evaluation of structured smoking cessation interventions based on the 5As, Motivational interviewing and Cognitive Behavioral Therapy.

Antimicrobial Activity of Antibacterial Sutures in Oral Surgery: A Scoping Review.

OBJECTIVE: The aim of this scoping review was to explore and synthesise the current evidence on the antimicrobial activity of antibacterial suture materials used in oral surgery. METHODS: The review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Extension for Scoping Reviews. A bibliographic search was carried out in the PubMed and Scopus databases to retrieve all human clinical studies that investigated the antimicrobial efficacy of antibacterial-coated sutures used in oral surgery. Included studies were screened and extracted independently by 2 examiners. Data were tabulated and qualitatively described. RESULTS: The search initially returned 150 articles and resulted in 5 included studies after the duplicates' removal and the full-text screening. Selected studies were published from 2014 to 2019. Three studies (60%) were randomised clinical trials, whilst the remaining studies did not report information on randomisation. The antimicrobial agents for coated sutures included triclosan and chlorhexidine. In almost all the studies, antibacterial-coated sutures exhibited lower bacterial retention compared to those without coating. CONCLUSIONS: Within limitations, the antimicrobial-coated sutures employed in oral surgery exhibited good results in terms of their microbicidal activity when compared with sutures that were not coated. Considering the high variability and confounding factors identified in the included studies, more high-quality research is needed to confirm these results. Antimicrobial-coated sutures could represent a promising and clinically valid strategy to reduce microbial colonisation in oral surgery. The reduced bacterial adherence is likely to improve the clinical success of the surgical procedures. Yet, the cost-benefit ratio of antimicrobial-coated sutures should be assessed in larger clinical trials to confirm their efficacy over conventional noncoated sutures.

Effects of Electronic Nicotine Delivery Systems Substitution on Body Weight Status: Protocol for a Systematic Review and Meta-Analysis.

BACKGROUND: Weight gain following smoking cessation is a well-documented concern, often attributed to the absence of nicotine's metabolic influence. The adoption of Electronic Nicotine Delivery Systems (ENDS) has been used to achieve smoking cessation, with claims of aiding weight control. However, existing reviews present conflicting conclusions on ENDS' impact on weight status, necessitating a rigorous evaluation. OBJECTIVE: We aim to conduct a systematic review with meta-analysis to assess the actual impact of ENDS on weight status in individuals who have ceased or reduced conventional smoking. The primary goal is to provide clinicians with evidence-based insights into the potential effects of ENDS use as a smoking substitute on weight control. METHODS: Adhering to PRISMA-P (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols) guidelines, our systematic review will analyze randomized and nonrandomized controlled trials, clinical trials (quasi-experimental), and prospective or retrospective cohort studies on the weight status effects of ENDS among individuals who have either quit or reduced smoking. Searches will include PubMed, Scopus, and Cochrane Library, covering the period from 2010 to January 2024. A gray literature search and supplementary searches will be performed. Data will be extracted independently by 2 reviewers and quality assessments will be conducted concurrently. Quality assessments will use Joanna Briggs Institute tools, 2020 version, along with bias assessments for internal validity and reporting bias based on the Catalogue of Bias. The included studies will be examined for any internal data reporting discrepancies by using Puljak's checklist. Meta-analysis and subgroup analyses (ie, general ENDS usage, ENDS use coupled with a reduction in smoking exceeding 50%, and exclusive ENDS use for achieving smoking cessation) are planned. Certainty of evidence will be evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. RESULTS: The protocol has been registered in PROSPERO (CRD42023494974) and the entire systematic review is expected to be completed by April 2024. The main goal of this review is to retrieve all current human research studies investigating the influence of ENDS on weight management among individuals who have quit or reduced smoking. Furthermore, the review will assess the quality of these studies and examine potential biases to identify the most dependable evidence available. Dissemination strategies will include traditional journal publications, social media announcements, and a white paper. The latter, available for download and distributed at conferences, aims to reach a broad audience, including clinicians and ENDS users. CONCLUSIONS: The review will address the importance of informing health care professionals and patients about the current and robust evidence regarding the effects of transitioning to ENDS for smoking cessation on weight status. TRIAL REGISTRATION: PROSPERO CRD42023494974; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=494974. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/56324.

Assessment of bone regeneration after maxillary radicular cyst enucleation with or without bone grafting materials: a retrospective cohort study.

OBJECTIVE: The limitations of spontaneous bone healing underscore the necessity for exploring alternative strategies to enhance bone regeneration in maxillary radicular cyst cases. This retrospective study aimed to assess the impact of a bone substitute material (i.e., Bio-Oss) on bone volume regeneration following maxillary radicular cyst enucleation using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Seventy-three patients with maxillary radicular cysts were divided into two groups: one undergoing guided bone regeneration (GBR) with Bio-Oss and absorbable collagen membrane (n = 35), and the other receiving cyst excision alone (n = 38). Volumetric measurements using Amira software on CBCT scans evaluated bone regeneration, with cystic lesion shrinkage rates calculated. Intergroup comparisons utilized independent sample t-tests (P < 0.05), and linear regression analysis assessed the influence of preoperative cyst volume and group on bone healing. RESULTS: Both groups showed similar success rates in bone formation at the 12-month follow-up, with no significant differences between them (mean (SD), control: 75.16 (19.17) vs. GBR: 82 (20.22), P > 0.05). Linear regression analysis revealed a negative correlation between preoperative cyst volume and bone regeneration in both groups (P < 0.05). CONCLUSION: Bio-Oss may not significantly enhance bone augmentation in maxillary radicular cysts. In addition, preoperative cyst volume negatively affected the shrinkage rate of cystic lesions. CLINICAL RELEVANCE: Clinicians should consider patient-specific factors such as anatomy and lesion size when determining the need for bone substitute materials. Future research could focus on optimizing treatment protocols and alternative regenerative strategies to improve patient outcomes in maxillary cyst cases.

Comparing pre- and postoperative etoricoxib administration versus only postoperative on third molar extraction sequelae and oral health quality of life: a prospective quasi-experimental study.

OBJECTIVES: This study aimed to compare the impact of pre- and postoperative etoricoxib administration versus only postoperative on third molar extraction sequelae and oral health quality of life. MATERIALS AND METHODS: This prospective quasi experimental study involved 56 patients, divided into a study group receiving preemptive etoricoxib 120 mg before surgery and postoperative etoricoxib 120 mg (n = 28), and a control group receiving preemptive placebo before surgery and postoperative etoricoxib 120 mg (n = 28). Follow-up assessments were conducted at 3- and 7-days post-surgery, recording swelling, trismus, and adverse events. Patients rated perceived pain using the visual analog scale (VAS) and completed an oral health-related quality of life (OHRQoL) questionnaire at specified intervals. Statistical analysis employed non-parametric tests (i.e., the Mann-Whitney test, Friedman test, and Wilcoxon sign test) with P < 0.05. RESULTS: Significantly lower VAS scores were reported in the study group throughout the follow-up period (P < 0.05). Pharmacological protocol did not have a significant impact on postoperative edema and trismus (P > 0.05). However, double etoricoxib intake significantly improved postoperative quality of life on day 3 after surgery (P < 0.05). CONCLUSIONS: Pre- and postoperative etoricoxib 120 mg intake in third molar surgery reduced postoperative pain and enhanced postoperative quality of life on day 3 after surgery. Importantly, it was equally effective in managing swelling and trismus compared to exclusive postoperative intake. CLINICAL RELEVANCE: Preemptive etoricoxib use may decrease patient discomfort following impacted mandibular third molar extraction.

Impact of pecking amplitude on cyclic fatigue of new nickel-titanium files.

OBJECTIVES: The aim of this study is to determine the cyclic fatigue resistance of Mtwo Minimal in static and dynamic tests, with different amplitudes of pecking movements, at intracanal temperature. MATERIALS AND METHODS: Two hundred new 25-mm Mtwo Minimal rotary files (#10/0.035, #17.5/0.045, #25/0.05, #40/0.03, #45/0.03) were tested in static and dynamic cyclic fatigue tests at 35°C (±1°C). An artificial stainless-steel canal was used. In the dynamic mode, axial movements were set at 1 and 3 mm. The number of cycles to fracture (NCF) was recorded and statistically analyzed by one-way analysis of variance (p < 0.05). RESULTS: The 3-mm dynamic test showed significantly increased NCF than the other tests for the #10/0.035, #17.5/0.045, and #25/0.05 files (p < 0.05). The #40/0.03 and #45/0.03 files showed no significant differences in all the tests (p > 0.05). CONCLUSION: Mtwo Minimal showed higher cyclic fatigue resistance in the dynamic test than the static test, except for the larger instruments. The 3-mm pecking amplitude increased the cyclic fatigue resistance of the smaller instruments.

Respiratory health effects of e-cigarette substitution for tobacco cigarettes: a systematic review.

BACKGROUND: E-cigarettes (electronic nicotine delivery system, ENDS) have been presented as a harm reduction strategy for people who smoke tobacco cigarettes but who cannot achieve abstinence, or for those who wish to continue to enjoy nicotine and the habit of smoking. What are the health effects of the substitution of ENDS for tobacco cigarettes? This systematic review evaluates the evidence of human clinical tests on the respiratory effects of ENDS use in participants who smoke tobacco cigarettes. METHODS: A registered and published protocol was developed conforming to PRISMA 2020 and AMSTAR2 standards. The literature search was conducted in PubMed, Scopus, and the CENTRAL Cochrane Library and updated to May 2022. Three supplementary searches and a grey literature search were performed. Studies were evaluated with the JBI quality tools and the Oxford Catalogue of Bias. Due to the heterogeneity (diversity) of the studies, a narrative data synthesis was performed on the test findings plus three sub-group analyses. RESULTS: The review consists of sixteen studies and twenty publications. Spirometry tests comprised the majority of the data. In total, 66 respiratory test measurements were reported, out of which 43 (65%) were not significant. Statistically significant findings were mixed, with 9 tests showing improvements and 14 measuring declines, none of which was clinically relevant. Ten studies were rated at a high risk of bias, and six had some concerns primarily due to inadequate research designs and the conduct of the studies. Reporting bias was documented in thirteen studies. CONCLUSIONS: Most of the studies showed no difference in respiratory parameters. This indicates that ENDS substitution for smoking likely does not result in additional harm to respiratory health. Due to the low quality of the studies, confidence in the conclusions is rated as low. Robust studies with a longer duration and sufficient power are required to validate any potential benefits or possible harms of ENDS substitution. Registration PROSPERO #CRD42021239094, International Registered Report Identifier (IRRID): DERR1-10.2196/29084.

Cyclic fatigue resistance of different nickel-titanium instruments in single and double curvature at room and body temperatures: A laboratory study.

The aim of this study was to compare the cyclic fatigue resistance of nickel-titanium instruments inside single and double-curved canals at different temperatures. 160 HyFlex EDM #20.05 (HEDM), VDW.ROTATE #20.05 and #25.06, Mtwo #25.06 were randomised (n = 10) for the dynamic cyclic fatigue tests according to the curvature (i.e. single and double) at 20° ± 1°C and 35° ± 1°C. The number of cycles to fracture (NCF) was analysed by two-way ANOVA with p < 0.05. Fatigue resistance of all instruments significantly decreased at body temperature in single and double curvatures, except for HEDM in double curvature. The NCF was significantly lower in double curvature than single at both temperatures for all files, except for VDW.ROTATE #20.05 at 35° ± 1°C. Within the study limitations, temperature significantly impaired cyclic fatigue resistance of all files except HEDM #20.05 in double curvature. Similarly, double curvature had a detrimental effect on cyclic fatigue resistance of all files except for VDW.ROTATE #20.05 at body temperature.

Identifying spin bias of nonsignificant findings in biomedical studies.

OBJECTIVE: The purpose of this research note is to share a technique for the identification of spin bias that we developed as part of a living systematic review on the cardiovascular testing of e-cigarette substitution for cigarette smoking. While some researchers have remarked on the subjective nature of ascertaining spin bias, our technique objectively documents forms of spin bias arising from the misrepresentation of nonsignificant findings and from the omission of data. RESULTS: We offer a two-step process for the identification of spin bias consisting of tracking data and findings and recording of data discrepancies by describing how the spin bias was produced in the text. In this research note, we give an example of the documentation of spin bias from our systematic review. Our experience was that nonsignificant results were presented as causal or even as significant in the Discussion of studies. Spin bias distorts scientific research and misleads readers; therefore it behooves peer reviewers and journal editors to make the effort to detect and correct it.

Shaping ability of Procodile and R6 Reziflow nickel-titanium reciprocating instruments in curved mesial root canals of mandibular molars: A MicroCT study.

To compare the shaping ability of Procodile and R6 Reziflow instruments used in reciprocating motion in severely curved root canals, assessed with micro-computed tomography (µCT). Fourteen extracted human mandibular first molars were randomly assigned to two instrumentation techniques (n = 14 mesial root canals): Procodile or R6 Reziflow. For both groups, root canals were prepared to the working length up to a size 25, .06 taper. Molars were virtually divided into apical, middle and coronal thirds and µCT was used to scan all samples pre- and post-root canal. Canal transportation, centring ability, volume, surface area and unprepared area were evaluated. Geometrical parameter changes were compared with preoperative values (one-way analyses of variance and Tukey multiple comparison post-hoc test) between groups and Student t-test within groups (α = 0.05) Significantly less transportation was observed associated with the Procodile technique in the molar's coronal third compared to the R6 Reziflow technique (p < .05). No significant differences in root canal centring ability, volume, surface area and unprepared area were observed. Procodile showed a lower percentage increase of surface area compared to R6 Reziflow (p < .05). The Procodile and R6 Reziflow techniques applied to first molar root canal performed similarly except for the less transportation observed in the coronal third using Procodile. RESEARCH HIGHLIGHTS: MicroCT analysis of canal geometry before and after instrumentation revealed that Procodile and R6 Reziflow showed a similar shaping ability to shape curved root canals without substantially modifications of the original tooth anatomy.

Influence of Coronal Flaring on the Shaping Ability of Two Heat-Treated Nickel-Titanium Endodontic Files: A Micro-Computed Tomographic Study.

Nickel-titanium (NiTi) usage is associated in endodontics with some complications including canal transportation. Centering ability of a NiTi file is the ability to stay centered in the root canal system during instrumentation. Any undesirable deviation from the natural canal path is indicated as canal transportation. A possible strategy to improve the centering ability of NiTi instruments is the pre-enlargement of the coronal third of the root canal to minimize coronal interferences. This procedure is known as coronal flaring. The aim of this study was to perform a micro-computed tomographic (micro-CT) evaluation of the effect of coronal flaring on canal transportation and centering ability of two heat treated nickel-titanium rotary instruments, 2Shape (Micro Mega, Besançon, France) and HyFlex CM (Coltène Whaledent, Altstätten, Switzerland). Thirty extracted mandibular molars with two independent mesial canals were selected and randomly instrumented (n = 15 canals) with One Flare (Micro Mega, Besançon, France) before HyFlex CM, HyFlex CM (without coronal flaring), One Flare before 2Shape and 2Shape (without coronal flaring). One Flare (Micro Mega, Besançon, France) was introduced 4 mm below the canal entrance for canals prepared with coronal flaring. HyFlex CM and 2Shape were used accordingly to manufacturers' instructions. New files were used for each canal. During and after instrumentation, irrigation procedures were performed. Micro-CT images were obtained pre- and post-preparation to measure and record root canal transportation and centralization. They were reconstructed from root apex to canal orifices, generating approximately 1000 sections per specimen. The anatomical thirds were determined by dividing the number of cross-sectional slices by three. Root canal transportation and centralization were determined by Gambil method, and the mean values were analyzed by repeated measures analysis of variance followed by multiple comparisons of Bonferroni to compare the different instrumentations procedures and the root thirds (p < 0.05). As for root canal transportation, 2Shape reported significantly higher values compared to HyFlex CM in the cervical region independently from the coronal flaring. In the apical region, 2Shape caused significantly minor canal transportation when used with coronal flaring with compared with the absence of coronal flaring. Regarding the centralization, HyFlex CM showed higher values than 2Shape in the cervical, independently from coronal flaring. In the apical region, 2Shape with coronal flaring exhibited significant major centering ratio, compared with not. Within the limitations of this study, coronal flaring reduced canal transportation and improved centralization of the 2Shape files in the apical section while it had no significant influence on shaping ability of the HyFlex CM instruments. Coronal flaring could represent a valid strategy to improve the shaping ability of NiTi files knowing that its benefit could be influenced by the shaping file used.

Torsional, Static, and Dynamic Cyclic Fatigue Resistance of Reciprocating and Continuous Rotating Nickel-Titanium Instruments.

INTRODUCTION: The aim of this study was to evaluate torsional, dynamic, and static cyclic fatigue resistance of the reciprocating One RECI (OR; Micromega, Besançon, France), WaveOne Gold (WOG; Dentsply Maillefer, Ballaigues, Switzerland), rotary One Curve (OC, MicroMega), and ProTaper Next X2 (PTN X2; Dentsply Sirona, Charlotte, NC) instruments. METHODS: A total of 120 OR (n = 30), WOG (n = 30), OC (n = 30), and PTN X2 (n = 30) nickel-titanium instruments were used. Torque and rotation angle until failure under static torsion loading were measured according to ISO 3630-1. Static and dynamic fatigue resistance was measured as the time to fracture in an artificial stainless steel canal with a 60° angle and 5-mm radius of curvature at intracanal temperature. The results were analyzed with 1-way analysis of variance and the post hoc Tukey test. The alpha-type error was set at 5%. Fracture instruments from torsion and fatigue tests were examined with a scanning electron microscope. RESULTS: OR showed higher static fatigue resistance and rotation angle at fracture than WOG, OC, and PTN X2 (P < .05). WOG exhibited higher torsional resistance than the others (P < .05). The cyclic fatigue tests in dynamic mode had higher TTF than static for the PTN X2 and WOG groups (P < .05). In the dynamic tests, OR and WOG showed higher TTF than OC and PTN X2 (P < .05). CONCLUSIONS: Under these experimental conditions, One RECI exhibited suitable mechanical properties with the highest cyclic fatigue resistance and angle of rotation among the tested instruments.

Influence of kinematics and incidence angles on the cutting efficiency of two single-file nickel-titanium rotary instruments.

To compare the cutting efficiency of F6 Sky Taper (F6ST) and One Curve (OC) with different kinematics and cutting inclinations. Cutting efficiency of 80 new F6ST and OC was tested at 90° and 70° inclination in relation to the sample, in continuous rotation and reciprocation, against standardised gypsum samples for 120 seconds using a customised device. Data expressed as weight loss and length of the sample cut were analysed using two-way analysis of variance and Tukey t-test (P<.05). F6ST showed significantly higher cutting efficiency in reciprocation, while OC in continuous rotation. Regardless of inclination, F6ST showed statistically higher values than OC in reciprocation, while OC exhibited higher cutting ability in continuous rotation. The 70° inclination significantly improved the cutting efficiency of both files. Reciprocation improved the cutting efficiency of F6ST while continuous rotation enhanced cutting ability of OC. An inclined insertion improved the cutting ability, independently from the movement.

Respiratory and Cardiovascular Health Effects of e-Cigarette Substitution: Protocol for Two Living Systematic Reviews.

BACKGROUND: Despite the clear risks of tobacco use, millions of people continue to smoke. Electronic nicotine delivery systems (ENDS), commonly called e-cigarettes, have been proposed as a substitute for those who are unwilling or unable to quit. Current systematic and narrative reviews on the health effects of ENDS use, particularly respiratory and cardiovascular effects, have come to differing conclusions. OBJECTIVE: We conducted two systematic reviews to critically assess and synthesize available human studies on the respiratory and cardiovascular health effects of ENDS substitution for people who smoke. The primary goal is to provide clinicians with evidence on the health effects of ENDS substitution to inform their treatment recommendations and plans. The twin goal of the reviews is to promote health literacy in ENDS users with facts on the health effects of ENDS. METHODS: These two reviews will be living systematic reviews. The systematic reviews will be initiated through a baseline review. Studies will be evaluated using the JBI quality assessment tools and a checklist of biases drawn from the Centre for Evidence Based Medicine Catalogue of Bias. A narrative synthesis is planned because of the heterogeneity of data. A search for recently published studies will be conducted every 3 months, and an updated review will be published every 6 months for the duration of the project or possibly longer. RESULTS: The baseline and updated reviews will be published in a peer-reviewed journal. The findings of the reviews will be reported in a white paper for clinicians and a fact sheet for people who use ENDS. CONCLUSIONS: The substitution of ENDS for cigarettes is one way to potentially reduce the risks of smoking. Clinicians and their patients need to understand the potential benefits and possible risks of substituting ENDS for cigarettes. Our living systematic reviews seek to highlight the best and most up-to-date evidence in this highly contentious and fast-moving field of research. TRIAL REGISTRATION: PROSPERO CRD42021239094; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=239094. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/29084.

Cutting efficiency of heat-treated nickel-titanium single-file systems at different incidence angles.

Cutting efficiency of Reciproc R25 (REC) and Reciproc blue R25 (REB) at different inclinations was evaluated. Sixty new files were tested at 90°, 70° and 45° of inclination in relation to the sample (n = 10), using a customised machine. All files were activated in reciprocation against standardised gypsum blocks for 120 s. Cutting efficiency was determined by measuring the block weight loss with an analytical balance and measuring the length of the block surface cut using a digital calliper. Data were statistically analysed (two-way ANOVA, Bonferroni t-test) with the significance level set at P < 0.05. There was no difference for REC among the tested angles. REB had no statistical difference between 90° and 70°; however, its cutting efficiency significantly increased at 45°. There was a significant difference between REC and REB at 45° only. Under these conditions, increased file inclination to 45° and blue heat treatment improved cutting efficiency of reciprocating files.