Biomedical subjects

M Waplington

Publications and source records attributed to M Waplington.

4 recordsLinked to original sources

PubMed1997

Incidence of root face alteration after ultrasonic retrograde cavity preparation.

PROBLEM: Ultrasonic root end preparation is now a recognized clinical procedure. Advantages claimed include improved access to the surgical site (because of reduced root end bevel), and faster more conservative preparation of the root end cavity. However, cracking of the root face has been reported after preparation. OBJECTIVES: The aim of this study was to determine the incidence of root end cracking at varying ultrasonic power levels with a replica technique and scanning electron microscopy. STUDY DESIGN: The root canals of 55 single-rooted teeth were prepared to size 40 apically and obturated with laterally condensed gutta perch and sealer. Root ends were resected at 90 degrees 3 mm from the apex. Class 1 cavities (n = 5) were prepared with retro tips in a Neosonic handpiece with different power settings. Time of preparation and load applied were constant. Another experimental group (n = 5) was prepared with a no. 1 rotary bur. A replica technique with addition-cured silicone impression material and epoxy resin was used to prevent drying artefacts. Specimens were viewed under scanning electron microscope for alterations of the root face. RESULTS: Results showed no root face cracking across the full range of instrument power settings, although chipping of the retrograde cavity margins was observed. No cracking was noted in bur-prepared teeth.

Analysis of Variance↗

PubMed1996

Cutting characteristics of a sonic root-end preparation instrument.

The aim of this study was to investigate the cutting ability of retro tips powered by a sonic handpiece (MM 1500, Micro Mega, Prodonta, Geneva, Switzerland). Two levels of the following variables were evaluated in this study: a) power setting with the an inlet ring half or fully open, b) orientation of tip perpendicular or parallel to the long axis of the handpiece, c) length of tip 2 or 3 min, d) loading of 25 or 50 grams, e) tip size 35 or 55. The substrate used was 1 mm thick sections of bovine bone and load was controlled by using a load cell interfaced with a transducer meter. Instrumentation time was fixed at 10 seconds with water irrigation. A 2(5) full factorial analysis was performed with two replications making a total of 64 experimental units. The resultant depth of cut was measured using a stereo microscope at x50 magnification. Analysis of the data indicated that all variables had a significant effect on cutting (ANOVA p < 0.05). The most significant factor was power, followed by tip length tip orientation, width and load. An increase in loading resulted in tip constraint and a reduction of cutting at the lower power setting. In conclusion sonically activated retro tips were found to cut satisfactorily with instrument air inlet ring opening/power having the main effect.

Analysis of Variance↗

PubMed1995

Cutting ability of an ultrasonic retrograde cavity preparation instrument.

The aim of this study was to investigate the cutting ability of a working ultrasonic instrument designed for surgical endodontic use (Neosonic, Amadent Corp, Cherry Hill, NJ, USA). Three designs of tip, designated CT 1 to CT 3 were calibrated by measuring their displacement amplitudes in air using light microscopy over a range of power settings. Extracted teeth were sectioned longitudinally and polished to produce a smooth dentine surface onto which the tips were applied for 1 minute over the above range of power settings at a load of approximately 20 g. The depth of cut in the dentine surface was measured using a two dimensional surface profilometry technique. Results showed that a raising of the power setting produced an increase in displacement amplitude and cutting ability for all tip designs. This increase was linear, with minimal cutting occurring at lower power settings. In conclusion the ultrasonic tips could be successfully used to remove dentine, and medium to high power settings optimised their efficiency.

Analysis of Variance↗

PubMed1995

Sonic instruments in root canal therapy.

Although hand instrumentation is considered the most acceptable method of preparing root canals, sonic instruments may be useful additions to the endodontic armamentarium. Sonic instrumentation may be incorporated as an adjunct to traditional techniques for shaping the root canal. The use of such instruments may assist the practitioner during root canal treatment in general practice.

Dental Instruments↗