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.

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.

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.

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.

Fracture strength of 3-units fixed partial dentures fabricated with metal-ceramic, graphene doped PMMA and PMMA before and after ageing: An in-vitro study.

OBJECTIVES: To evaluate the fracture strength and linear elongation at break of three-units fixed partial dentures (FPDs) fabricated with traditional and new materials for fixed prosthodontics before and after ageing. METHODS: Sixty models of three-units FPDs were fabricated and cemented onto a Co-Cr model simulating the replacement of a maxillary second premolar. The samples were randomly divided into 3 groups: metal-ceramic (MCR), graphene-doped polymethylmethacrylate (PMMA-GR) and polymethylmethacrylate (PMMA). Half of the samples were directly subjected to fracture test, while the remaining half underwent an ageing process and then a fracture loading test using an electrodynamic testing machine. Fracture load and elongation at break values were taken and statistically analysed. RESULTS: Significant differences were detected between the different materials (p<0.05). All groups showed a reduction of the fracture load and elongation at break values after ageing, but not statistically significant, except for PMMA group (p = 2.012e-19) (p = 3.8e-11). CONCLUSIONS: MCR and PMMA-GR three-units FPDs showed higher fracture strength and lower elongation at break compared to PMMA. MCR and PMMA-GR had higher resistance to ageing processes compared to PMMA. CLINICAL SIGNIFICANCE: PMMA-GR could be considered a material for long-term provisional restorations as its mechanical behaviour and ageing resistance are more like MCR than PMMA.

The Role of Pecking Motion Depths in Dynamic Cyclic Fatigue Resistance: In Vitro Study.

OBJECTIVE: This is the first study evaluating the impact of different pecking motion depths on dynamic cyclic fatigue resistance of different endodontic instruments. METHODS: Four nickel-titanium systems (Hyflex EDM OneFile 25/. ∼; Rotate 25/0.6; Mtwo 25/0.6; Reciproc Blue R25) were tested. Forty instruments from each group were subjected to 4 different pecking movements to evaluate their cyclic fatigue resistance. The distances for the pecking motion were 3-mm forward and backward, 1-mm (3-mm forward and 2-mm backward), 2-mm (4-mm forward and 2-mm backward), and 3-mm (5-mm forward and 2-mm backward). Speeds were 100 and 200 mm/min for the descending and ascending motion, respectively. The times to fracture (TtF) in seconds were recorded for each instrument. Data were statistically analysed by using 2-way ANOVA and Bonferroni multiple comparison post hoc test (P < .05). RESULTS: All instruments had a significant increase in cyclic fatigue resistance during the forward dynamic motion compared with the axial continuous. Overall, the heat-treated instruments reported higher fatigue strength than the untreated files (P < .05). Reciproc Blue and Hyflex EDM showed higher TtF in the forward movements of 1-/2-mm and 2-mm (P < .05), respectively while Mtwo 25.06 and Rotate 25.06 in the forward movement of 3-mm (P < .05). CONCLUSIONS: Within the limits of this in vitro study, the pecking motion depths had varying impacts on the cyclic fatigue resistance of instruments. Reciproc Blue and Hyflex EDM performed significantly better with pecking motions of 1-and 2-mm. Improving endodontic instrument durability through specific pecking depths has the potential for improving clinical performance and reducing instrument failures.

Effectiveness of continuous chelation irrigation protocol in endodontics: a scoping review of laboratory studies.

This scoping review aimed to synthesize and explore the current boundaries and limitations of laboratory research on the effectiveness of continuous chelation irrigation protocol in endodontics. This scoping review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Extension for Scoping Reviews. Literature search was conducted on Pubmed and Scopus to identify all laboratory studies evaluating smear layer and hard-tissue debris removal or, antimicrobial efficacy, or dentine erosion induced by continuous chelation. Two independent reviewers performed the all review steps and the relevant items were recorded. Seventy-seven potentially relevant studies were identified. Finally, 23 laboratory studies met the eligibility criteria for qualitative synthesis. Seven studies focused on the smear layer/debris removal outcome, 10 on antimicrobial activity, and 10 on dentine erosion. In general, the continuous chelation protocol was equally or more effective in the cleanliness of root canals and antimicrobial activity compared with traditional sequential protocol. In addition, etidronate solutions seemed to be milder chelating agents compared to those with EDTA, thus resulting in reduced or no dentine erosion and roughness modification. Yet, the methodological differences among the included studies limit the results' generalizability. The continuous chelation seems to be equally or more effective in all investigated outcomes when compared with the traditional sequential protocol. The methodological variability among the studies and shortcomings in the methods employed limit the generalizability and clinical relevance of the results. Standardized laboratory conditions combined with reliable three-dimensional investigation approaches are necessary to obtain clinically informative findings.

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.

A scoping review of new technologies for dental plaque quantitation: Benefits and limitations.

OBJECTIVES: To determine the validity and reliability of novel digitalized tools for dental plaque detection and explore the benefits and limitations connected to their use. DATA: Reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Extension for Scoping Reviews. All human clinical studies comparing dental plaque detection using digitalized systems against a standard reference were included. SOURCES: PubMed and Scopus were screened from 01 January 2013 to 28 September 2023. Bibliographies of primary studies and principal peer-reviewed scientific journals were manually searched. STUDY SELECTION: The initial search identified 576 articles, with a total of 13 included in the review, published between 2015 and 2023. Most of the studies included (77 %) were cross-sectional with three being prospective. Digital devices captured 2D and 3D images via cameras and intra-oral scanners, respectively. The Turesky's modified plaque index was the most frequent clinical index. Correlation with clinical examination was moderate to strong, with good to excellent intra- and inter-system agreement. CONCLUSIONS: Within the limitations of this scoping review, image analysis-based plaque detection systems demonstrated good correlations with clinical plaque indices, using both 2D and 3D imaging systems. Whilst digital plaque detection devices offer advantages in terms of procedural standardization and reproducibility, they also have limitations, therefore currently, their application should be underpinned by a comprehensive clinical examination. CLINICAL SIGNIFICANCE: Digital plaque detection tools, that provide standardized measurements and store acquired images, facilitate more informed feedback to patients. This objective analysis may enhance clinician confidence in their utility for clinical trials and other applications.

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.

Assessing the impact of obturation techniques, kinematics and irrigation protocols on apical debris extrusion and time required in endodontic retreatment.

The aim of the study was to evaluate the impact of kinematics and irrigation protocols on the extrusion of apical debris during removal of different obturation techniques. A total of 144 single-rooted teeth were instrumented and obturated with Thermafil+AH Plus, Thermafil+AH Plus Bioceramic and single gutta-percha cone+AH Plus Bioceramic. Samples were divided according to the retreatment kinematics: continuous rotation or Jeni motion. Each sub-group was subjected to conventional irrigation or irrigation activated by EDDY. Extruded debris was collected in Eppendorf tubes, weighted and retreatment time was digitally recorded. Data were analysed with two-way ANOVA (p < 0.05). Debris extrusion was not significantly different between all groups. EDDY activation system and CanalPro Jeni required significantly longer time compared with other groups to remove Thermafil+AH Plus and single cone+AH Plus Bioceramic. Within current limitations, obturation technique, irrigation protocol and kinematics tested had no influence on apical extrusion debris, while they significantly impacted the retreatment time.

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.

Effectiveness of the platelet-rich fibrin in the control of pain associated with alveolar osteitis: a scoping review.

OBJECTIVES: The aim of this scoping review was to determine the effectiveness of the platelet-rich fibrin in the control of pain associated with alveolar osteitis. MATERIALS AND METHODS: Reporting was based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Extension for Scoping Reviews. A literature search was conducted in the PubMed and Scopus databases to identify all clinical studies on the application of platelet-rich fibrin in the control of pain caused by alveolar osteitis. Data were extracted independently by two reviewers and qualitatively described. RESULTS: The initial search returned 81 articles, with 49 identified after duplicates removal; of these, 8 were selected according to the inclusion criteria. Three of the eight studies were randomized controlled clinical trials, and four were non-randomized clinical studies, two of which were controlled. One study was case series. In all of these studies, pain control was evaluated using the visual analog scale. Overall, the use of platelet-rich fibrin resulted effective in the control of pain determined by alveolar osteitis. CONCLUSIONS: Within the limits of this scoping review, the application of platelet-rich fibrin in the post-extra-extraction alveolus reduced the pain associated with alveolar osteitis in almost all the included studies. Nevertheless, high-quality randomized trials with adequate sample size are warranted to draw firm conclusions. CLINICAL RELEVANCE: Pain associated with alveolar osteitis causes discomfort to the patient and is challenging to be treated. Use of platelet-rich fibrin could be a promising clinical strategy for pain control in alveolar osteitis if its effectiveness will be confirmed by further high-quality studies.

The effect of different kinematics on apical debris extrusion with a single-file system.

To compare the amount of extruded debris caused by different motions using a single-file system. Fifty mandibular first molar teeth were randomized into 5 groups (n = 10) according to the motion tested: Optimize Torque Reverse (OTR), TF Adaptive Motion (TFA), continuous rotation (CR), reciprocation motion (+ 150°, -30°) (REC), and Jeni motion (Jeni). One Curve single file 25/06 (Micro-Mega, Besançon, France) was used in all experimental groups. The root canals were irrigated with 2.5% NaOCl, and the extruded debris were collected at pre-weighted glass vials. The glass vials were kept inside an incubator for one week at 70 °C to dry out the irrigating solution. The extruded debris was quantified by subtracting the pre-instrumentation from the post-instrumentation weight of the glass vials. The time required for each instrumentation procedure was digitally recorded. All data were analyzed statistically with one way ANOVA and post hoc Tukey test (P < 0.05). All the motions extruded apically debris with Jeni mode caused significantly less debris extrusion than TFA, REC, and CR (P < 0.05) while no significant difference emerged with OTR. Preparation time was not significantly different in all groups. Within the limits of the present study, all the kinematics produced apically debris extrusion, with Jeni reporting a similar amount of debris compared with OTR and significantly less than TFA, REC, and CR. Preparation time was similar among the tested kinematics.

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.

Influence of different heat treatments and temperatures on the cyclic fatigue resistance of endodontic instruments with the same design.

OBJECTIVES: To evaluate the influence of different heat treatments and temperatures on the cyclic fatigue resistance of 2Shape instruments (Micro Mega, Besancon, France) with the same design. MATERIALS AND METHODS: A total of 80 2Shape TS1 (#25/.04) and 80 TS2 (#25/.06) files with different heat treatments (no heat-treated, NHT; C-Wire; T-Wire; CM-Wire) were tested at room (25° ± 1 °C) and body (37° ± 1 °C) temperatures in 16-mm stainless steel artificial canal with a curvature of 60° and 5 mm of radius. Files were tested in continuous rotation at 300 rpm using a customized device. Cyclic fatigue resistance was expressed in the number of cyclic to fracture (NCF). The phase transformation temperature of each file was determined by differential scanning calorimetry. Data were statistically analyzed using the two-way ANOVA and the Bonferroni post-hoc test with p < 0.05. RESULTS: All CM-Wire TS1 and TS2 files showed higher NCF than the other groups at both temperatures (p < 0.001). C-Wire TS2 showed higher resistance than NHT and T-Wire TS2 (p < 0.001), with no significant differences between the last two. Body temperature significantly decreased NCF of all tested files (p < 0.05) except for NHT and T-Wire TS1. CONCLUSIONS: Body temperature negatively affected the cyclic fatigue resistance of C-Wire and CM-Wire TS1 and of all TS2 files compared with room temperature. The CM-Wire instruments exhibited the highest cyclic fatigue resistance of all tested files. CLINICAL RELEVANCE: Heat-treated nickel-titanium files can differently perform according to environmental temperature and file dimensions. The CM-Wire 2Shape prototypes displayed the highest flexural resistance in all experimental conditions.