Effect of the temperature of sodium hypochlorite on the cyclic fatigue resistance of ProTaper Gold rotary files.

BACKGROUND: Instrument fracture is one of major challenges during root canal treatment. In order to reduce such errors, it seems necessary to investigate the effects of potentially impactful factors. One of such factors could be the temperature of an agitator. OBJECTIVES: This study examined the effects of different temperature of the sodium hypochlorite solution on the cyclic fatigue resistance of ProTaper Gold (PTG) rotary files. MATERIAL AND METHODS: Forty-five PTG S1 rotary files were tested in a metal block that simulated a canal curvature angle of 60° and a curvature radius of 5 mm. They were randomly divided into 3 groups of 15 according to sodium hypochlorite temperatures of 22°C (group 1), 4°C (group 2) and 37°C (group 3). Files from each group were rotated at 300 rpm in the block at each temperature. The number of cycles to fracture was calculated and the fragment length was measured. The fractured surfaces were examined by means of scanning electron microscopy (SEM). The statistical analysis was completed using the Kolmogorov-Smirnov and Kruskal-Wallis tests, and the IBM SPSS Statistics for Windows software, v. 22.0, at a significance level of 5%. RESULTS: The cyclic fatigue resistance of the PTG rotary files was not significantly affected by the temperature of sodium hypochlorite (p > 0.05). CONCLUSIONS: Increasing the temperature of sodium hypochlorite to 37°C or decreasing it to 4°C did not significantly affect the cyclic fatigue resistance of PTG rotary files.

Endodontic and Surgical Management of Iatrogenic Root Injury Caused by Orthodontic Miniscrew Placement: A Case Report.

One of the potential serious complications, associated with the inter-radicular placement of an orthodontic miniscrew, is root injury. This article reports the endodontic and surgical treatments of an iatrogenic root perforation in a mandibular first molar caused by the placement of an orthodontic miniscrew anchorage. The 24-month follow-up showed a successful treatment outcome.

Periopathogens in atherosclerotic plaques of patients with both cardiovascular disease and chronic periodontitis.

BACKGROUND: Atherosclerosis and periodontitis are both chronic inflammatory diseases. Although a strong relationship between the two has already been established, the underlying mechanism is unknown. The present study was conducted aiming to detect the deoxyribonucleic acid (DNA) of Aggregatibacter actinomycetemcomitans (A.a), Campylobacter rectus (C.r), and Porphyromonas gingivalis (P.g) in subgingival and atherosclerotic plaques of patients with both chronic periodontitis and cardiovascular disease (CVD). METHODS: In this cross sectional study, patients with coronary artery disease (CAD) and moderate to severe periodontitis which were scheduled for coronary artery bypass grafting (CABG) were enrolled in the study. The subgingival plaques were collected before surgery. All samples were examined for the detection of selected periopathogens using polymerase chain reaction (PCR). RESULTS: The subgingival and atherosclerotic plaque samples of 23 patients were examined. The DNA of P.g, A.a, and C.r were found to be positive in 43.47%, 43.47%, and 78.26% of subgingival plaques, and 13.04%, 17.39%, and 8.69% of atherosclerotic plaques, respectively. In all cases, the bacterial species found in atherosclerotic plaques were also found in the subgingival plaques of the same patient. CONCLUSION: This study demonstrated the presence of periopathogens in atherosclerotic plaques of patients with chronic periodontitis. More studies are required to ascertain the exact role of these periopathogens in atherosclerotic plaque formation.

Genetic diversity of Staphylococcus aureus strains from a teaching hospital in Isfahan, Iran: The emergence of MRSA ST639- SCCmec III and ST343- SCCmec III.

BACKGROUND AND OBJECTIVES: Staphylococcus aureus is an important pathogen that can be colonized in the nose and increase the risk of spreading infections in hospitals. The present study aimed at determining the phenotypic and genotypic characterization of S. aureus strains isolated from patients and healthcare workers (HCWs) from a teaching hospital in Isfahan, Iran. MATERIALS AND METHODS: This cross-sectional study was performed on 262 nasal swabs and 23 clinical isolates that were collected from a teaching hospital during February and April 2016. Staphylococcal cassette chromosome mec (SCCmec) and multilocus sequence typing (MLST) were performed for selected isolates. RESULTS: Overall, 23% and 18% of healthcare workers and patients were carriers, respectively. Methicillin-resistant S. aureus (MRSA) rate was 13%, 33% and 52% in nasal HCWs, nasal patients, and clinical samples, respectively. The molecular typing of MRSA isolates revealed that the most common SCCmec type is SCCmec type III (88%). The highest rate of resistance was observed against tetracycline and erythromycin, with 48.7%. The most frequently detected toxin genes among S. aureus isolates were hla (99%) and sea (44%), moreover, pvl genes were detected in (40%) of MRSA isolates. The results of MLST showed 7 different sequence types (STs): ST859 (2/9), ST6 (2/9), ST639 (1/9), ST343 (1/9), ST239 (1/9), ST291 (1/9) and ST25 (1/9). CONCLUSION: Our results revealed that ST clones associated with healthcare-associated MRSA (HA-MRSA) are actively circulating among nasal carriage in our healthcare setting, and thus, effective infection control policies are needed to reduce nasal carriage in healthcare settings.

Molecular characteristics and antibiotic resistance pattern of Staphylococcus aureus nasal carriage in tertiary care hospitals of Isfahan, Iran.

Carriage of S. aureus in the anterior nares seems to play a significant role in the pathogenesis of infection. This study aimed to determine the molecular characteristics and antibiotic susceptibility pattern of S. aureus isolates obtained from the nasal carriage of health care workers (HCWs). This study was performed during July 2014 to July 2015 at three tertiary care hospitals. Nasal samples were collected from the nasal cavity of HCWs. Standard microbiological methods were used for identification of S. aureus isolates. Antibiotic susceptibility pattern was determined by the disc diffusion method. Determination of SCCmec typing and virulence genes was performed by the PCR method. From the isolates of 340 nasal swab samples of HCWs, 65 S. aureus strains (19%) including 22 (33.8%) MRSA were isolated. The highest sensitivity for MRSA isolates was towards vancomycin and rifampicin, each with 90.9%. Overall, 17% (11/65) and 92.3% (60/65) of S. aureus isolates were positive for pvl and hla genes, respectively. The rates of SCCmec types II, III, IV, V and I among MRSA isolates were 36.4 %, 22.7 %, 22.7 %, 9.1% and 4.5% respectively. The results of the present study indicate that S. aureus nasal carriage with potential virulence ability still remains a significant healthcare problem, especially in hospital environments.

Comparison of Postoperative Pain after Root Canal Preparation with Two Reciprocating and Rotary Single-File Systems: A Randomized Clinical Trial.

INTRODUCTION: Root canal preparation techniques may cause postoperative pain. The aim of the present study was to compare the intensity of postoperative pain after endodontic treatment using hand files, single file rotary (OneShape), and single file reciprocating (Reciproc) systems. METHODS AND MATERIALS: In this single-blind, parallel-grouped randomized clinical trial a total of 150 healthy patients aged between 20 to 50 years old were diagnosed with symptomatic irreversible pulpitis of one maxillary or mandibular molars. The teeth were randomly assigned to three groups according to the root canal instrumentation technique: hand files (control), OneShape and Reciproc. Treatment was performed in a single visit by an endodontist. The severity of the postoperative pain was assessed by the visual analogue scale (VAS) after 6, 12, 24, 48 and 72 h. Data were analyzed using the Kruskal-Wallis and Mann-Whitney U tests. RESULTS: The patients in control group reported significantly higher mean postoperative pain intensity at 12, 24, 48, and 72 h compared to the patients in the two other groups (P<0.05). There was no significant difference in mean intensity of postoperative pain between Reciproc and OneShape at 5 time points (P>0.05). CONCLUSION: The instrumentation kinematics (single-file reciprocating or single-file rotary) had no impact on intensity of postoperative pain.