A comparison of root canal preparations using stainless steel, Ni-Ti hand, and Ni-Ti engine-driven endodontic instruments – an in vitro study

The main advantage of nickel titanium instruments is that they permit canal preparation with less transportation and ledging. Hand used Ni-Ti and rotary Ni-Ti instruments have a wider range of elastic deformation and greater flexibility. The aim of the present study was to evaluate and compare the preparation time, loss of working length, apical transportation, instrument deformation and fracture with stainless steel, Ni-Ti hand and Ni-Ti rotary endodontic instruments. Fifty freshly extracted human mandibular molars with curved roots were collected and stored in 10% formalin. The samples were divided into 3 groups of 15 each. The access opening was made for each tooth and the biomechanical preparation was carried out using crown down pressureless technique in all the groups. Group I was instrumented with stainless steel files, group II with hand Ni-Ti and group III with Ni-Ti rotary files. The preparation time to enlarge each canal was recorded in minutes and seconds, which included only active instrumentation. Following preparation, the final length of each canal was subtracted from the original length to give the loss of working length. SEM photographs of the deformed and fractured instruments were taken. The apical transportation was measured using computer software (Microdraw 4.1). The readings were noted and statistically analyzed.The results of this in vitro study showed that the mean preparation time was less with Ni- Ti rotary (1.85 min) when compared to hand Ni-Ti (6.33) and stainless steel files (6.73), which was statistically significant. The loss of working length was more for stainless steel group which was statistically significant (P<0.05) when compared with the other 2 groups.One instrument in stainless steel and one in Ni-Ti rotary files were fractured. Only one instrument in stainless steel file deformed permanently. Apical transportation was found to be greater in stainless steel group than other groups (P<0.01) which was statistically significant. Considering the parameters in this study, Ni-Ti rotary files proved to perform better than the other two groups. Key words: Canal preparation; crown-down pressure less technique; double exposure radiographic technique. DOI: 10.3329/bjms.v9i4.6689Bangladesh Journal of Medical Science Vol.09 No.4 July 2010 pp.223-230

Download Full-text

Effectiveness of Ultrasonic and Manual Dynamic Agitation Techniques in Irrigant Penetration: An in vitro Study

World Journal of Dentistry ◽

10.5005/jp-journals-10015-1439 ◽

2017 ◽

Vol 8 (3) ◽

pp. 207-212

Author(s):

BS Suprabha

Keyword(s):

In Vitro Study ◽

Vitro Study ◽

Passive Ultrasonic Irrigation ◽

Canal Irrigation ◽

Root Canals ◽

Lateral Canal ◽

Group I ◽

Working Length ◽

Ultrasonic Irrigation

ABSTRACT Aim The aim is to compare the extent of irrigant penetration into root canals up to the working length and in simulated lateral canals after passive ultrasonic irrigation (PUI) and manual dynamic agitation (MDA). Materials and methods Root canals of 36 single-rooted extracted teeth were shaped using rotary files. Irrigation was done with 5.25% sodium hypochlorite and 17% ethylenediaminetetraaceticacid. Teeth were decalcified in 5% nitric acid. Lateral canals were created by inserting 10 K-files and then, the teeth were cleared using methyl salicylate. Samples were randomly divided into three groups of 12 teeth each: Group I — Control, group II — PUI, and group III — MDA. A contrast solution was delivered to the root canals during final irrigation and activation. Specimens were photographed using dental operating microscope, and the mean length of dye penetration was measured. Results Data were analyzed using analysis of variance (ANOVA), Tukey test, and repeated measures ANOVA. Passive ultrasonic irrigation group showed the highest penetration of the irrigant upto the working length followed by MDA. Manual dynamic agitation and PUI groups had equivocal results in lateral canal irrigation. Conclusion Passive ultrasonic irrigation technique is the most effective in delivering the irrigants up to the working length. The effectiveness of PUI and MDA is equivocal in lateral canal irrigation, and hence, MDA can be considered an alternative to PUI, in the case of nonavailability of PUI. Clinical significance The clinician can consider the use of MDA technique for irrigant agitation in root canals as an alternative to PUI, based on the extent of irrigant penetration. How to cite this article Khare M, Suprabha BS, Yadav A, Shenoy R, Boaz K, Rao A. Effectiveness of Ultrasonic and Manual Dynamic Agitation Techniques in Irrigant Penetration: An in vitro Study. World J Dent 2017;8(3):207-212.

Download Full-text

Assessment of shear bond strength of brackets bonded by direct and indirect techniques: an in vitro study

Dental Press Journal of Orthodontics ◽

10.1590/s2176-94512012000400008 ◽

2012 ◽

Vol 17 (4) ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Roberto Hideo Shimizu ◽

Karlos Giovani Grando ◽

Isabela Almeida Shimizu ◽

Augusto Ricardo Andriguetto ◽

Ana Cláudia Moreira Melo ◽

...

Keyword(s):

Bond Strength ◽

Shear Bond Strength ◽

In Vitro Study ◽

Adhesive System ◽

Vitro Study ◽

Group Iii ◽

Indirect Bonding ◽

Group I ◽

Group Ii

OBJECTIVE: This in vitro study was designed to evaluate the shear bond strength (SBS) of orthodontic metal brackets bonded by direct and indirect techniques. METHODS: Thirty healthy human maxillary premolar teeth were used. The teeth were divided into three groups of 10 teeth each: Group I - indirect bonding with SondhiTM Rapid-Set system (3M/Unitek), Group II - indirect bonding with TransbondTM XT adhesive system (3M/Unitek) and Group III - direct bonding with TransbondTM XT adhesive system (3M/Unitek). After bonding and obtaining the specimens for the study, the specimens were subjected to SBS testing in a universal testing machine (Emic, model DL-500). The Kolmogorov-Smirnov test was applied to ascertain that the data had a normal distribution and the Bartlett test to check whether there was homogeneity of variance. One-factor analysis of variance was performed and, subsequently, Tukey's test for paired means. A 5% significance level was adopted. RESULTS: The results of Group I were 67.6 (N) and 5.9 (MPa); Group II, 68.9 (N) and 6.1 (MPa) and Group III (control), 92.5 (N) and 8.1 (MPa). CONCLUSION: It can therefore be concluded that the means for Group III were significantly higher compared with Groups I and II in both Newton (N) and Megapascal (MPa) values. The means attained by the indirect bonding technique used in Groups I and II, however, exhibited no statistically significant differences.

Download Full-text