McGreevey, Edward J.2023-03-242023-03-2419951995https://hdl.handle.net/2144/45905PLEASE NOTE: This work is protected by copyright. Downloading is restricted to the BU community: please click Download and log in with a valid BU account to access. If you are the author of this work and would like to make it publicly available, please contact open-help@bu.edu.Thesis (MSD)--Boston University, Henry M. Goldman School of Graduate Dentistry, 1995 (Department of Endodontics)Includes bibliography: leaves 140-149.The purpose of this investigation was to evaluate the efficiency in which Nickel-Titanium ProFile .04 Taper Series 29 Rotary Instruments effectively clean and shape the root canal system when compared to the conventional cleaning and shaping hand technique as described by Dr. Schilder when utilizing ProFile Series 29 hand instruments. Additionally, the specimens were judged with regard to the elimination of morphological aberrations within the root canal system, instrument deformation and separation, and the time to prepare each specimen. A total of fifty-two roots were divided into three groups, seventeen of which were cleaned and shaped in accordance with Dr. Schilder's technique and ProFile Series 29 hand instruments, eighteen were instrumented with ProFile .04 Taper Series 29 Rotary Instruments, and seventeen were manipulated with a combined technique in which the apical portion of the roots were cleaned and shaped with Series 29 hand instru ments, according to the Schilder Technique, and the body preparation was completed utilizing ProFile .04 Taper Series 29 Rotary Instruments. An additional ten roots were prepared for evaluation in a SEM, seven were instrumented with ProFile .04 Taper Series 29 Rotary Instruments and three were manipulated using the combined technique. All specimens were stabilized in a customized mounting jig and x-rayed before manipulation. Following canal preparation, the specimens were three dimensionally obturated with vertical compaction of warm gutta­ percha and Kerr sealer, and placed back in the mounting jig for a final x­ ray. The specimens were then subjected to a clearing process to render the roots transparent. All specimens were judged in their ability to fulfill the five design objectives of cleaning and shaping for canals that will be filled with warm gutta-percha. Instrumentation with ProFile .04 Taper Series 29 Rotary Instruments failed to produce a preparation which was able to fulfill Dr. Schilder's five design objectives of cleaning and shaping, and all exhibited parallelism and undershaping throughout the preparation. Furthermore, 38.8% displayed the presence of fins and projections in the gutta-percha of the cleared specimens; evidence of canal space that was neither cleaned nor shaped. Of the seven roots examined under the SEM, all seven revealed evidence of extensive pulpal debris and tissue throughout the preparation. Moreover, all representative canals unveiled areas that were untouched by the instruments. Also, instrument deformation occurred in nine of thirty-five roots prepared with the ProFile .04 Taper Series 29 Rotary Instruments or 25.7% of the time, and of these, two exhibited separation of the instrument tip. The average time to prepare each specimen, in this group, was twenty-seven minutes. Of the seventeen roots prepared with the combined technique, only 64.7% were able to fulfill these same parameters, the other 35.3% exhibited parallelism in some portion of the canal preparation; with one specimen displaying an "hour glass" canal shape. The average time to prepare each specimen was 35.7 minutes and all roots revealed gutta­ percha which was well adapted to the canal space with no evidence of fins or projections. None of the sections evaluated under the SEM revealed the evidence of pulpal debris and tissue. Furthermore, the tubules appeared to be open. Cleaning and shaping of the root canal system in accordance with Dr. Schilder's, utilizing ProFile Series 29 hand files and reamers, was able to satisfy the five design objectives of cleaning and shaping 88.3% of the time. Only two specimens (11.7%) failed to fulfill these parameters, and these manifested parallelism in some portion of the canal preparation. Also, there was no visible evidence of any instrument deformation, or breakage, in this group. The average time to prepare each specimen was 40.6 minutes, and all cleared specimens exposed gutta­ percha which was well adapted to the canal space with no evidence of fins or projections.en-USThis work is protected by copyright. Downloading is restricted to the BU community. If you are the author of this work and would like to make it publicly available, please contact open-help@bu.edu.Dental InstrumentsThesis/Dissertation