Long-term effect of curcuminoid treatment on resin-to-dentin bond strength.

Endogenous dentin proteases contribute to the degradation of collagen fibrils in the hybrid layer. Recently, inhibition of host-derived proteases by curcuminoids has shown promising results. The aim of this study was to evaluate the effect of curcuminoid treatment on the microtensile bond strength (µTBS) after 24 h or 12 months of storage. Fifty-four extracted sound human molars were flattened to mid-coronal dentin and divided into nine groups. After phosphoric acid-etching for 15 s, the dentin was experimentally treated for 60 s using 100 µM or 200 µM of curcumin, diflourobenzocurcumin, or demethoxycurcumin dissolved in 1% and 2% dimethyl sulfoxide (DMSO)/water solutions. Untreated and DMSO-treated groups served as controls. After bonding agent application, each tooth was restored with dental composite. The molars were sectioned into 0.9 × 0.9 × 6 mm beams. The µTBS testing was performed after 24 h and 12 months of storage in artificial saliva. Data were analyzed using regression analyses. Failure patterns were evaluated using scanning electron microscopy. Dentin treatment with curcuminoids did not adversely affect 24-h µTBS compared to controls. After 12 months, the µTBS of curcuminoid groups was statistically significantly higher than the controls. This study indicates the feasibility of using curcuminoids as protease inhibitors.

A comparative assessment of orthodontic treatment outcomes using the quantitative light-induced fluorescence (QLF) method between direct bonding and indirect bonding techniques in adolescents: a single-centre, single-blind randomized controlled trial.

INTRODUCTION: The aim of this two-arm parallel trial was to evaluate enamel demineralization in fixed orthodontic treatment using an indirect bonding technique in comparison to a direct bonding technique by the quantitative light-induced fluorescence (QLF) method. DESIGN, SETTINGS AND PARTICIPANTS: Fifty-six patients who needed fixed orthodontic treatment were randomly separated into either the direct bonding group or the indirect bonding group. The presence and extent of lesions on the buccal surfaces of all teeth, except the molar teeth, were assessed. The percentage of fluorescence loss (ΔF and ΔFmax), the degree of demineralization (ΔQ) and lesion area (WS area) were determined using the system's software. The data were analysed with the Wilcoxon signed-rank and Mann-Whitney U-tests (P < 0.05). INTERVENTIONS: Treatment with a direct bonding or an indirect bonding technique. RESULTS: This study was completed with 25 patients in the indirect bonding group (12 females, 13 males; mean age: 15.42 ± 1.71 years) and 26 patients in the direct bonding group (12 females, 14 males; mean age: 14.73 ± 1.65 years). In the indirect bonding technique, a few teeth (especially mandibular left canine: 50.45 ± 93.48; 95% confidence interval: -12.35 and 113.26) were found to develop significant white spot lesion (WSL) formation (P < 0.05). However, the number of teeth with demineralization was higher in the direct bonding group (P < 0.05). CONCLUSION: The bonding procedures used in the indirect bonding technique contribute to reducing the degree of WSL formation. Further, the use of flowable composite adhesives in this bonding process is more effective at reducing the appearance of WSLs than in cases where conventional composite adhesives are used. LIMITATIONS: The limitation of our trial may be the small sample size and the short follow-up time for the patients. HARMS: No harms were detected during the study. PROTOCOL: The protocol was not published before trial commencement. REGISTRATION: This trial was registered post hoc at 'Clinical Trials' (http://www.clinicaltrials.gov), registration number (ID): NCT03738839.

Evaluation of the relationship between compliance with the follow-up and treatment protocol and health literacy in bladder tumor patients.

Objective: To investigate the relationship between the compliance of bladder cancer patients with cystoscopic follow-up and the treatment protocol, and their health literacy. Methods: Patients who underwent transurethral resection surgery for bladder tumor were found to have non-muscular invasive bladder carcinoma on pathology examination and then underwent cystoscopic follow-up for 1 year or more were included in the study. Cystoscopic follow-up was recommended to the low- and high-risk groups in terms of progression and recurrence. The patients were evaluated with the Health Literacy Survey-European Union scale. Results: The mean age of the patients was 67.13 ± 10.77 years. The treatment continuity rate was 80.50% (n = 33) in the adequate health literacy group (n = 41) and significantly higher than the 56.50% (n = 48) rate in the inadequate health literacy group (n = 85) (p = .008). The health literacy results revealed that the health promotion and general index score was higher in the group of patients under the age of 65. Conclusions: Adequate health literacy in bladder cancer patients is associated with better compliance with the treatment protocol. Young patients show better compliance with the follow-up protocol recommended by the physician. Increasing the follow-up protocol compliance of elderly patients with inadequate health literacy is necessary.

Thiol-disulphide balance in infertility secondary to varicocele.

Oxidative stress plays an important role in the development of infertility secondary to varicocele. We aimed to investigate the dynamic thiol-disulphide homeostasis as an oxidative stress marker in the spermatic vein of infertility secondary to varicocele. Sixty-one patients with varicocele were included in the study. Blood was drawn from the median cubital vein and the testicular venous return side before the spermatic vein was separated during surgery. Total thiol, native thiol, disulphide, ischaemia modified albumin (IMA) and albumin values were measured from both the dilated spermatic vein and the median cubital vein. The disulphide/native thiol, disulphide/total thiol and native thiol/total thiol ratios were determined. The mean age of the patients was 27.0 ± 6.68 (15-50) years. While the albumin, native thiol and total thiol values and the native thiol/total thiol ratio were significantly lower (p = 0.004, p < 0.001, p < 0.001, p < 0.001 respectively), the IMA value and the disulphide/native thiol and disulphide/total thiol ratios were significantly higher (p < 0.001, p < 0.001, p < 0.001 respectively) in the samples taken from spermatic venous blood. Thiol-disulphide balance had deteriorated towards disulphide formation in the spermatic vein compared with the peripheral vein. Abnormal thiol-disulphide balance may be an independent risk factor for infertility secondary to varicocele.

Lymphocyte-to-monocyte ratio is a valuable marker to predict prostate cancer in patients with prostate specific antigen between 4 and 10 ng/dl.

OBJECTIVE: To evaluate the diagnostic value of serum inflammation markers derived from complete blood count in diagnosis of prostate cancer (PCa). METHODS: We retrospectively analyzed the data of 621 patients who underwent prostate biopsy between March 2013 and April 2018. Age, prostate specific antigen (PSA), free PSA, platelet count, neutrophil count, lymphocyte count, monocyte count, prostate volume (PV) and pathology result of the patients were recorded. Patients were grouped as benign prostatic hyperplasia (BPH), prostatitis and PCa. Patients were also grouped according to PSA values, as PSA < 4 , PSA 4-10 and PSA > 10 ng/dl. RESULTS: The mean lymphocyte-to-monocyte ratio (LMR) value of the patients with PCa was significantly lower in the entire cohort (p = 0.047). In the PSA 4-10 ng/dl range, LMR value wassignificantly lower in patients with PCa than those with BPH or prostatitis (p = 0.012). In this PSA range, free/total PSA ratio and LMR were significant factors to predict PCa. The cut-off values of LMR, free/total PSA were 3.05 and 0.15 respectively. The sensitivities, spesificities, positive predictive values (PPV) and negative predictive values using LMR cut-off, free/total PSA cut-off and their combination were assessed. Specificity and PPV of the combination group were higher (97.2%, 83.3% respectively) compared to free/total PSA cut-off group (91.6%, 76.6%) and LMR cut-off group (67.8%, 43.7%). CONCLUSIONS: LMR is a useful tool at detecting PCa especially in patients with PSA value between 4 and 10 ng/dl. The combination of free/total PSA ratio and LMR improves the diagnostic accuracy more than the use of free/total PSA ratio alone.

Comparison of the effectiveness of IPSS and VPSS without any help in LUTS patients: a prospective study.

AIM: To compare the correlation of visual prostate symptom score (VPSS) and international prostate symptom score (IPSS). To investigate the effect of educational level and age in the responses to VPSS and IPSS. METHOD: Three hundred and nine patients who gave consent and applied via LUTS to our institution were included in this study. They were requested to fill IPSS and VPSS. The patients were divided into two groups as middle-aged and elderly with a cutoff point of 65 years. They were divided into six groups based on educational level. SPSS was used for the statistical evaluation. RESULTS: The mean age of the patients was 61.5 ± 8.9 years. The correlation was found between IPSS and VPSS (p < .05). Education was found not to contribute for answering IPSS and VPSS (p = .332 and .138, respectively). No difference was found between the middle-aged and elderly groups in terms of the rates of inability to answer IPSS and VPSS (p = .177 and .681, respectively). CONCLUSIONS: There is a correlation between VPSS and IPSS. VPSS can be used as an auxiliary or alternative tool instead of IPSS in evaluating LUTS; however, has no superiority to IPSS in elderly group. Currently, the best option to exclude bias in illiterate group is VPSS.

Treatment of Posterior Hip Dislocation due to Juvenile Idiopathic Arthritis. Report of Two Cases.

Introduction: Juvenile idiopathic arthritis ( JIA) is a persistent autoimmune-inflammatory disease that affects children younger than 16. Aggressive synovitis of the hip may cause joint destruction, hip protrusion, erosion, pseudosubluxation, dysplasia, and osteoarthritis. Subluxation of the hip had been reported previously. However, dislocation of the hip in JIA is an extremely rare situation, and only two cases have been reported up to date. Reduction of the dislocated hip has to be performed in any way. However, there is no algorithm to be followed for the treatment of hip dislocations caused by JIA. Case Presentation: In this study, we presented two cases of hip dislocation caused by JIA.Case 1: An 11-year-old boy had JIA and chronic recurrent multifocal osteomyelitis (CRMO). X-rays and computed tomography (CT) revealed a posterior dislocation of the left hip. An urgent operation was planned for the reduction of the hip. Avascular necrosis, dysplasia, or erosions were not evident at the last follow-up.Case 2: An 11-year-old girl was referred to the hospital with excessive left hip pain starting 24 h ago. A limited synovectomy with joint irrigation was performed. However, pathological examination of the synovium showed chronic inflammation consistent with JIA. On the post-operative 10th day, the patient was consulted for an increase in hip pain and deformity of the left hip. X-rays and MRI revealed posterior dislocation of the left hip with synovial hypertrophy. An urgent operation was planned. The hip could be reduced under anesthesia with mild traction, and a pelvipedal cast was applied only for 3 weeks. Avascular necrosis, dysplasia, destruction, or erosions were not evident at the last follow-up. Conclusion: For early diagnosed patient reduction under anesthesia and medial soft-tissue contracture release; for late diagnosed patient medial soft-tissue contracture release, capsulotomy and synovectomy were effective to prevent destruction and early degenerative changes of the hip joint for treatment of dislocation caused by JIA.

Identification of HLA alleles involved in immune thrombotic thrombocytopenic purpura patients from Turkey.

Thrombotic thrombocytopenic purpura (TTP) is one of the rare group disorders classified as thrombotic microangiopathies (TMAs). Approximately 90% of TTP developed immune-mediation by the formation of antibodies against the enzyme ADAMTS-13. The exact cause is unknown. To establish an association between human leukocyte antigen (HLA) and autoimmune basis, as susceptibility or protection against the disease, we contributed a study aiming to evaluate the role of HLA in immune-mediated TTP (iTTP). Considering epidemiological factors such as age, sex, ethnicity, and geographical origins, we contributed the study in our country, Turkey, which consist of a very heterogeneous population. Patients' data collection was retrospectively from electronic database on two University hospitals having big therapeutic apheresis service. Control arm was healthy people registered as stem cell donors matched in terms of age and sex. The frequency of HLA-DRB1 and HLA-DQB1 alleles between acquired TTP and the control group was compared using the chi-square method. Yates correction and logistic regression were performed on these results. A total of 75 iTTP patients and 150 healthy individuals enrolled to the study. HLA-DRB1∗11, HLA-DQB1∗03, HLA-DRB1∗11:01, HLA-DRB1∗14:01, HLA-DRB1∗13:05, HLA-DRB1∗11 + HLA-DQB1∗03 allele pair and HLA-DRB1∗15 + HLA- DQB1∗06 were proved to be susceptibility allele pairs for iTTP. HLA-DRB1∗15, HLA-DRB1∗01:01, HLA-DRB1∗07:01, HLA-DRB1∗13:01, HLA-DRB1∗14:54, HLA-DQB1∗05:01, HLA-DQB1∗02:02 and HLA-DRB1∗07 + HLA-DQB1∗02 allele pair were found to be protective against iTTP. Our findings support an association with iTTP across very heterogenous populations in Turkey.

In vitro evaluation of the minimum bactericidal concentrations of different root-end filling materials.

AIM: The aim of this study was to evaluate the minimum bactericidal concentrations (MBC) of root-end filling materials ProRoot MTA, MTA Angelus and IRM. MATERIALS AND METHODS: Macrodilution broth method was used. Microorganisms used were: Staphylococcus aureus (ATCC 29213), Enterococcus faecalis (ATCC 29212) and Streptococcus mutans. Serial two-fold dilutions of root-end filling samples were prepared in macrodilution tubes with concentrations ranging from 1/2 to 1/512. The samples dilutions were incubated for 24 hours. After incubation, 0.1 ml of diluted culture was inoculated onto the surface of supplemented sheep blood agar (Merck, Germany) and all plates were incubated at 37°C in aerobic condition for 24 hours. The MBC was defined as the lowest concentration of root-end filling samples where no growth was recorded. RESULTS: MBC of both mineral trioxide aggregate (MTA) products against S. aureus were recorded as 15.62 mg/ml and for IRM 31.25 mg/ml MBC for both MTA groups against E. faecalis were recorded as 31.25 mg/ml and for IRM 62.5 mg/ml. MBC of all root-end filling samples against S. mutans were recorded as 62.5 mg/ml. CONCLUSION: All tested root-end filling materials showed acceptable MBC against S. aureus and E. faecalis. CLINICAL SIGNIFICANCE: All tested materials can be used safely for filling of a root-end cavity.

Treatment Process of Primary Prostate Leiomyosarcoma: A Rare Case Report.

Prostate sarcoma is an extremely rare malignancy that accounts for only %0.1 of all neoplasms of the prostate gland. Primary prostate leiomyosarcoma (PLSOP) is the most common subtype in adults. Due to the fact that it is an extremely rare malignancy, case reports have been reported frequently and several publications in the form of case series. The number of case reports in the world is less than 200. Our opinion is that publishing such rare diseases and bringing them to the literature will have positive benefits both scientifically and for the patients. We present a patient with PLSOP and discuss the clinical, diagnostic and therapeutic aspects of this rare malignancy. Keywords: Prostate, Leiomyosarcoma, Cancer, Prognosis.

Measurement and rapid assessment of indoor air quality at mass gathering events to assess ventilation performance and reduce aerosol transmission of SARS-CoV-2.

To assess risk factors for COVID-19 transmission and address the closure of mass gathering events since March 2020, the UK Government ran the Events Research Programme (ERP), following which it reopened live events in sports, music, and culture in July 2021. We report the rapid post-occupancy evaluation of Indoor Air Quality (IAQ) and associated long-range airborne transmission risk conducted in the Environmental Study of the ERP. Ten large venues around the UK were monitored with CO2 sensors at a high spatial and temporal resolution during 90 events. An IAQ Index based on CO2 concentration was developed, and all monitored spaces were classified in bands from A to G based on their average and maximum CO2 concentrations from all events. High resolution monitoring and the IAQ Index depicted the overall state of ventilation at live events, and allowed identification of issues with ventilation effectiveness and distribution, and of spaces with poor ventilation and the settings in which long-range airborne transmission risk may be increased. In numerous settings, CO2 concentrations were found to follow patterns relating to event management and specific occupancy of spaces around the venues. Good ventilation was observed in 90% of spaces monitored for given occupancies. Practical applications: High-resolution monitoring of indoor CO2 concentrations is necessary to detect the spatial variation of indoor air quality (IAQ) in large mass gathering event venues. The paper summarises COVID-19 ventilation guidance for buildings and defines a methodology for measurement and rapid assessment of IAQ during occupancy at live events that can be implemented by venue managers. Comparisons of the CO2 concentrations measured during the events identified the spaces at high risk of long-range transmission of airborne pathogens. Building operators should be mindful of the ventilation strategies used relative to the total occupancy in different spaces and the occupant's activities.

Apical extrusion of debris when using OneCurve, ProTaper Next and TruNatomy in curved canals.

BACKGROUND: The extrusion of apical debris is related to various factors, and may be affected by variations in technique or instrumentation system. Although the extrusion cannot be completely prevented, it is crucial to minimize the amount of extruded material. OBJECTIVES: The present study aimed to compare apical debris extrusion by the novel TruNatomy (TRN), OneCurve (OC) and ProTaper Next (PTN) instruments in curved root canals. MATERIAL AND METHODS: A total of 60 multi-rooted human mandibular molar teeth with moderate and severe curvature were selected and randomly divided into 3 groups. The root canals were prepared with the OC, TRN and PTN files. For collecting the debris extruded through the apical foramen, Eppendorf tubes were used. After the vaporizing period, the tubes were re-weighed, and the amount of the extruded debris was calculated by subtracting the initial weight from the final weight. Statistical analysis was performed with the Shapiro-Wilk and Kruskal-Wallis tests. The statistical significance level was set at p < 0.05. RESULTS: The least amount of debris was extruded with TRN and the greatest with PTN, but the difference between the groups was not significant (p = 0.257). CONCLUSIONS: All instrumentation systems were associated with debris extrusion. The tested file systems presented similar results in terms of apical debris extrusion in curved canals. The novel TRN system demonstrated promising results, comparable to OC and PTN.

Efficacy of various activation techniques on tubule penetration of resin-based and bioceramic root canal sealers: An in vitro confocal microscopy study.

To compare the penetration of Ah Plus and MTA Fillapex after irrigation activation with sonic, passive ultrasonic, SWEEPS and XP-Endo Finisher using confocal microscopy. Instrumented root canals of 160 mandibular premolar teeth were allocated randomly to four groups (n = 40/group) and eight subgroups according to the activation techniques and canal sealers (n = 20/subgroup). After the obturation, three sections at 1-2, 5-6 and 9-10 mm levels from the apex were examined. Penetration area and maximum penetration depth values were represented as mean and standard deviation, and results below 0.05 were considered statistically significant. For penetration area and maximum penetration depth, the statistical difference was found in terms of material, device and region (Maximum penetration depth: p = 0.006, p < 0.001, p < 0.001; Penetration area: p = 0.004, p < 0.001, p < 0.001). SWEEPS was found to be relatively higher than other groups. Sealers presented similar results when evaluated independently of the region. The use of SWEEPS for irrigation activation is promising in terms of tubule penetration.

Dentinal tubule penetration of gutta-percha with syringe-mix resin sealer using different obturation techniques: A confocal laser scanning microscopy study.

This study aimed to evaluate dentinal tubule penetration of the root canal filling material using various techniques such as cold lateral compaction, new generation thermoplastic core carrier and continuous-wave obturation. The root canals of premolar teeth were instrumented, and the teeth were allocated randomly to three groups (n = 15/group). After the obturation with three different techniques, three sections of 2-mm thickness at 2, 5 and 8-mm from the apex were examined under a confocal laser scanning microscope. The data were analysed of variance with a significance level of P < 0.05. There was no significant difference between techniques when parameters were evaluated in total (penetration depth P = 0.418, penetration area P = 0.701). The mean value of the cold lateral compaction group for maximum penetration depth was obtained higher than continuous wave (P = 0.004), whilst there was no significant difference between the thermoplastic core carrier and the other groups.

Composite repair: On the fatigue strength of universal adhesives.

OBJECTIVES: To determine whether the composition of universal adhesives and the use of silane coupling agents could affect the fatigue strength of composite repair. METHODS: Composite samples were aged in water at 37 °C for 90 days and bonded to fresh composite to produce twin-bonded bar-shaped composite specimens (2 × 2 × 12 mm). Five universal adhesives, a multistep composite repair system and a hydrophobic solvent-free resin associated to a separate silane coupling agent application were used for bonding. Composite samples were tested under 4-pointflexure initially at quasi-static loading (n = 12) followed by cyclic loading (n = 25). The stress-life fatigue behavior was evaluated following the staircase method at 4 Hz. The unfractured side of cyclic loaded beams were evaluated under SEM to determine crack initiation sites. Fatigue data was analyzed by ANOVA and Tukey test and Wilcoxon Rank Sum Test (α = 0.05). RESULTS: Bonding protocols were unable to restore the cohesive strength of the nanofilled composite (p < 0.05). Fatigue testing was more discriminative to reveal discrepancies in composite repair than conventional quasi-static loading. While the composition of universal adhesives affected composite repair potential, the highest endurance limits occurred for the separate silane coupling agent application. Crack propagation sites were mostly located on the aged composite surface. SIGNIFICANCE: Although a trend for simplification invariably overruns current adhesive dentistry, composite repair using solely universal adhesives may result in inferior repair potential. The additonal use of silane coupling agents remains as an important procedure in composite repairs.

Sealing ability of retrofilling materials following various root-end cavity preparation techniques.

The aim of this study is to compare the sealing efficacy of the retrograde cavity preparations prepared and filled with different equipment and materials. In the study, low speed burs, ultrasonic or Er, Cr:YSGG laser devices were used for cavity preparations and ProRoot MTA and MTA-Angelus as filling materials. Seventy-eight single-rooted teeth were instrumented, root filled, and grouped. Root-end cavities were prepared and filled by using the following: Group 1: Low-speed carbide bur + ProRoot MTA; Group 2: Low-speed bur + MTA-Angelus; Group 3: Ultrasonic retrotips + ProRoot MTA; Group 4: Ultrasonic retrotips + MTA-Angelus; Group 5: Er, Cr:YSGG laser tips + ProRoot MTA; Group 6: Er, Cr:YSGG laser tips + MTA-Angelus. Microleakage was measured using a fluid filtration technique. Differences in the fluid movement among groups were analyzed with a two-way analysis of variance (ANOVA) and LSD test. The results showed a significant difference between the groups prepared with laser and carbide bur (p < 0.05). No difference was found between root-end filling materials (p > 0.05). According to the results of the study, the cavities prepared with Er, Cr:YSGG laser demonstrated significantly lower microleakage in all the filling materials considered.

Effects of repeated sterilization cycles on the surface alterations of ProTaper Next, TF Adaptive, HyFlex CM, and 2Shape instruments.

Background. This study aimed to evaluate the effects of repeated sterilization cycles on the surface alterations of various nickel-titanium instruments, including ProTaper Next (PTN), TF Adaptive (TFA), HyFlex CM (HCM), and 2Shape (2S). Methods. Twenty-four new NiTi files of four different alloys were selected. The instruments in each group were divided into two equal groups, as follows: control and sterilization. The first group was chosen as the control without applying any sterilization procedure, while in group 2, five cycles of sterilization procedures were applied. The surface topographies were evaluated using scanning electron microscope (SEM) and atomic force microscope (AFM). The root mean square (RMS) and maximum height (MH) values and three-dimensional images were recorded. The data were analyzed with the Shapiro-Wilk test, one-way ANOVA, and post hoc Tukey tests. The statistical significance level was set at P ≤ 0.05. Results. Before the experiment, HCM demonstrated the highest RMS value, and 2S showed the lowest. After the procedures, the RMS and MH values deteriorated on the surface of PTX, TFA, and 2S (P < 0.001). The HCM was not affected by sterilization processes (P > 0.05). Conclusion. The initial irregularity on the surface did not affect the rate of alteration. The HCM files demonstrated superior surface properties after several cycles of sterilization. The PTN, TFA, and 2S presented similar surface responses after five cycles of autoclave sterilization.

A comparative investigation between ProTaper Next, Hyflex CM, 2Shape, and TF-Adaptive file systems concerning cyclic fatigue resistance.

Background. This study aimed to compare the cyclic fatigue resistance of ProTaper Next, Hyflex CM, 2Shape, and TF-Adaptive nickel-titanium endodontic file systems with various alloy properties and production methods and investigate the fractured cross-sectional surface of files due to cyclic fatigue by scanning electron microscopy (SEM). Methods. A total of 120 instruments were used (n=30). For standardization, #25/.06 apical diameter and taper angle were selected for each file system. The experiment of files was subjected to a static cyclic fatigue model. The time for files' failure was recorded with a digital chronometer and multiplied by the rotation speed to calculate the number of cycles. Kolmogorov-Smirnov, one-way ANOVA, and post hoc Bonferroni analysis were used for statistical analysis. Statistical significance was set at P < 0.05. Results. The number of cycles for the failure of files was compared between the groups, and significant differences were found (P < 0.05). The number of cycles for instrument failure was recorded from the highest to the lowest as follows: Hyflex CM, TF-Adaptive, ProTaper Next, and 2Shape. Conclusion. The files were fractured at different average numbers of cycles in an artificial canal in all the groups. The Hyflex CM demonstrated better cyclic fatigue resistance than TF Adaptive, ProTaper Next, and 2Shape file systems. Factors such as production patterns, alloy properties, and the phase in which the files were produced might affect the lifespan of file systems.

The pursuit of resin-dentin bond durability: Simultaneous enhancement of collagen structure and polymer network formation in hybrid layers.

OBJECTIVE: Imperfect polymer formation as well as collagen's susceptibility to enzymatic degradation increase the vulnerability of hybrid layers over time. This study investigated the effect of new dimethyl sulfoxide (DMSO)-containing pretreatments on long-term bond strength, hybrid layer quality, monomer conversion and collagen structure. METHODS: H3PO4-etched mid-coronal dentin surfaces from extracted human molars (n = 8) were randomly treated with aqueous and ethanolic DMSO solutions or following the ethanol-wet bonding technique. Dentin bonding was performed with a three-step etch-and-rinse adhesive. Resin-dentin beams (0.8 mm2) were stored in artificial saliva at 37 °C for 24 h and 2.5 years, submitted to microtensile bond strength testing at 0.5 mm/min and semi-quantitative SEM nanoleakage analysis (n = 8). Micro-Raman spectroscopy was used to determine the degree of conversion at different depths in the hybrid layer (n = 6). Changes in the apparent modulus of elasticity of demineralized collagen beams measuring 0.5 × 1.7 × 7 mm (n = 10) and loss of dry mass (n = 10) after 30 days were calculated via three-point bending and precision weighing, respectively. RESULTS: DMSO-containing pretreatments produced higher bond strengths, which did not change significantly over time presenting lower incidence of water-filled zones. Higher uniformity in monomer conversion across the hybrid layer occurred for all pretreatments. DMSO-induced collagen stiffening was reversible in water, but with lower peptide solubilization. SIGNIFICANCE: Improved polymer formation and higher stability of the collagen-structure can be attributed to DMSO's unique ability to simultaneously modify both biological and resin components within the hybrid layer. Pretreatments composed of DMSO/ethanol may be a viable-effective alternative to extend the longevity of resin-dentin bonds.