Endodontic Spiral Root-fillers B. G. Tidmarsh, BDS., FRACDS., Department of Conservative Dentistry, University of Otago Dental School, Dunedin, New Zealand. The difficulty of placing sealing cements and pasles within root canals bas stimulated tbe design of several palterns of spiral root fillers. Although convenient, these instruments are liable to break if ibey are allowed to bind against ihe walls of the canal (Figure 1.) Broken instruments of this lype may on occasions be removed by engaging ibem either witb another spiral filler or a fine endodontic file. However, all attempts to remove them may fail necessitaling the need for retrogiade (;bluralion of the canal or occasionally extraction of tbe rool may be indicated. Fracture of these instruments is a result not only of a weakness of tbeir intrinsic design bul also in a lack of appreciation of tbis weakness.

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'I'wo spiral fillers fractured within a root canal.

Several brands of spiral root-fillers were examined under bolh a stereoscopic optical microscope and a scanning electron microscope. Allliough the Meisinger* and MicroMeg-a* spiral fillers showed a smooth surface devoid of any major irregularities, the FKG*** instrument showed obvious distortion of the surface, presumably due lo the manner of its manufacture. All of ibese instruments appear to be made of coiled steel wire (Figures 2 and 3). They have very sharp unfinished ends tbat could easily catch in any irregularity within a canal. The Hawe-Neos**** filler on the olher hand appeared to bave an entirely different construction, Ihc flal steel blade is twisted and tapered (Figure 4) and the free end is well finished. All the instruments under investigation were stressed by grasping the free end and rotating them in a band-piece. All lbe coiled wire design fillers broke quite readily, although tbe spirals of the Meisinger filler opened out considerably before fracture occurred. Tbe Hawe-Neos design, witbout any loss of flexibility, appeared lo be considerably stronger than ihe other instruments tested. Breakage within a tootb is very uncommon witb this instrument. . , . . * ** *** **** 104

Hager &: Meisinger GMIIII, Dusscldorf, West Germany. Micro-Mega Export, Geneva. Switzerland. Flucker and HuRucnin SA., La Chaux-de-Fonds, Switzerland. Hawe-Neos, Gentilano, Switzerland. Journal of the British Endodontic Society. 1975 VoL8 No.2

Fractures vvilbin the tooth are more likely to occur if the spiral filler is revolving whilst being introduced into tbe canal. It is therefore, preferable to place the instrument to the lull depth before starting to rotate and withdraw it at the same time. However, for ihe purpose of placing cements and pastes within the root canal it is equally convenient and effective to use an endodontic reamer rotated by hand in tbe reverse direction from tbat employed in tbe preparalion of a canal. The use of cither a hand reamer in this manner or the Hawe-Neos filler should prevent many of these so calletl endodontic accidents.

2.

Coiled wire type of spiral filler.

3.

igli power of coiled wire spiral filler showing surface convolutions.

4.

llawf-Ncos spiral root filler.

ACKNOWLEDGMENT: M. D. McMillan, Department of Denial Sciences, University of Otago is thanked for assistance with the scanning electron microscopy. Journal of the British Endodontic Society, 1975 Vol.S No.2

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Endodontic spiral root-fillers.

Endodontic Spiral Root-fillers B. G. Tidmarsh, BDS., FRACDS., Department of Conservative Dentistry, University of Otago Dental School, Dunedin, New Ze...
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