Microsurgical instruments for root-end cavity preparation following apicoectomy: a literature review

Root-end cavities have traditionally been prepared by means of small round or inverted cone burs in a micro-handpiece. Since sonically or ultrasonical ly driven microsurgical retrotips became commercially available in the earl y 1990s, this new technique of retrograde root canal instrumentation has be en established as an essential adjunct in periradicular surgery. At first g lance, the most relevant clinical advantages are the enhanced access to roo t ends in limited working space and the smaller osteotomy required for surg ical access because of the various angled designs and small size of the ret rotips. However, a number of experimental studies comparing root-end prepar ations made with microsurgical tips to those made with burs have demonstrat ed other advantages of this new technique, such as deeper cavities that fol low the original path of the root canal more closely. The more centered roo t-end preparation also lessens the risk of lateral perforation. In addition , the geometry of the retrotip design does not require a beveled root-end r esection for surgical access thus decreasing the number of exposed dentinal tubules. A controversial issue of sonic or ultrasonic root-end preparation is the formation of cracks or microfractures, and its implication on heali ng success. The present paper reviews experimental and clinical studies abo ut the use of microsurgical retrotips in periradicular surgery and discusse s many issues raised in previous papers.