Comparative Evaluation of Smear Layer Removal Using Four Different Irrigation Techniques: An in-vitro Study

INTRODUCTION: Irrigation is the vital part of root canal debridement. Usually post biomechanical preparation, the canal walls are covered by smear layer. It is important to remove this layer before obturation for better bond between the filling and walls. Conventional needle irrigation doesn’t give us adequate cleaning, therefore, new irrigation techniques are being tried to facilitate better smear layer removal. AIM: The aim was to evaluate and compare the smear layer removal by PATS,  EndoActivator device, Passive ultrasonic irrigation and side vent needle irrigation from canal walls. MATERIALS AND METHODS:  60 extracted mandibular premolars were instrumented up to 35/.04 with Heroshaper files. Samples were divided into 4 groups randomly before final irrigation as follows: Group I (n=15): Irrigation with side vent needles (Nexus ltd.,India), Group II (n=15): Irrigation with EndoActivator (Advanced Endodontics, Santa Barbara, CA ) Group III (n=15): Irrigation with PATS ( InnovationsEndo,India), Group IV (n=15): Irrigation with ultrasonic tips (Mani inc.). Teeth were split and one-half of each tooth was chosen for SEM examination.  The images were taken at apical third and scoring was done according to criteria by Torabinejad et al in 2003. Data obtained were analyzed using Kruskal-Wallis analysis of variance followed by Mann–Whitney U-test for individual comparison. RESULTS: All irrigating systems remove smear layer but PUI has better cleaning ability as compared to other groups. CONCLUSION: Passive ultrasonic irrigation shows better smear layer removal as compared to other technique

To Study The Efficacy Of Reciprocating Single File System And Multifile Rotary Systems In Elimination Of Root Canal Bacteria And Endotoxins

AIM: To study the efficacy of reciprocating single file system and multifile rotary systems in elimination of root canal bacteria and endotoxins. MATERIAL AND METHOD: Forty permanent single rooted mandibular premolars with straight canals inoculated with Escherichia Coli suspension for 21 days were selected for the study. Teeth were randomly divided into four groups (n=10) according to instrumentation system: Grp. A–Reciproc (VDW); Grp. B–WaveOne (Dentsply Maillefer); Grp. C–MTwo (VDW); and Grp. D–K3( Sybron Endo); Bacterial and endotoxin samples were collected with a sterile paper point before instrumentation  and after instrumentation. Culture methods estimated the colony-forming units (CFU) and the Limulus Amebocyte Lysate test was used for quantification of endotoxins. Results so obtained were calculated and statistically analysed.  RESULT: Results at S1 concluded that bacteria and endotoxins were found in all of the investigated root canals. After instrumentation all systems were associated with the significant reduction of the bacterial load and endotoxins respectively: Grp. A– Reciproc (88.25% and 89.10%); Grp. B– WaveOne (83.53% and 80.59%); Grp. C– MTwo(79.41% and 75.84%) and Grp. D– K3 (67% and 74.4%). Statistically no difference was found amongst the instrumentation systems regarding bacteria and endotoxin elimination (P <0.05).  CONCLUSION: The reciprocating single file, Reciproc and WaveOne were as effective as the multifile rotary systems for the eradication of bacteria and endotoxins from root canals

Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

Accuracy of two different apex locators for working length determination during root canal retreatment of mandibular molars using two different retreatment files: An in vitro study

Aim: The aim of this study was to evaluate the accuracy of two different apex locators for working length determination during root canal retreatment of mandibular molars in an in vitro study. Method: Sixty extracted mandibular first molars with separate mesial canals and apical foraminae and one distal canal were selected. The mesiobuccal and distal canals were investigated; the length with the file tip at the major diameter was defined as the tooth length (TL). The canals were prepared with ProTaper files to 1 mm short of this and filled with gutta-percha and AH Plus sealer. One week later, the root fillings were removed using ProTaper and M2 retreatment files. Tooth length was remeasured and recorded as the retreatment tooth length (RTL). Then electronic measurements were taken at the major (electronic apex locator (EAL) major) and minor (EAL minor) foraminae with Root ZX and Apex ID apex locator as suggested by the instrument display. These lengths were compared with RTL and measurements 0.5 and 1 mm short of this distance. Results: For both canals, no significant difference was found between RTL and EAL major, and 0.5 mm short of RTL and EAL minor with Root ZX apex locator and protaper retreatment files. There were significant differences found between Apex ID apex locator with M2 retreatment files readings. Conclusion: Root ZX apex locator was more accurate as compared to Apex ID apex locator in determining the working length in teeth after removing the root canal obturating material