Purpose The aim of this study was to answer the question: For patients requiring apicoectomy (apicectomy/root-end resection) and retrograde (root-end) obturation (filling), which retrograde obturation (root-end filling) material(s) is/are the most effective, as determined by reduction in periapical radiolucency and elimination of signs and symptoms?
Materials and methods A MEDLINE and a Cochrane search (two specified searches) were conducted to identify randomised (RCT) and nonrandomised controlled clinical trials (CCT), cohort studies (CS) and case-control studies (CCS), published between 1966 and 2002, October week 4, conducted on humans, and published in English, German and French language, relating to retrograde obturation materials following apicoectomy.
Results The MEDLINE and the Cochrane search identified 324 and 21 published articles, respectively. The Cochrane search identified three additional articles to the MEDLINE-search articles. Fourteen studies met the inclusion criteria: two were RCTs, six were CCTs, none was a CS and six were retrospective CCSs. Nine of the 14 studies compared a new retrograde (root-end)-filling material to amalgam, 4 of the 14 studies compared orthograde root canal fillings to retrograde (root-end) amalgam and the fourteenth study compared variations of a resin composite (Retroplast) when used in combination with the bonding agent Gluma (Bayer AG, Gluma 1 and 2). The two RCTs indicated that glass ionomer cement appeared to be equivalent to amalgam. The six CCTs indicated that orthograde filling with gutta-percha and sealer was more effective than amalgam retrograde (root-end)-filling (one trial). Similarly, retrograde (root-end)-filling with (i) composite and Gluma (Bayer AG, Leverkusen, Germany) as bonding agent (one trial), (ii) reinforced zinc oxide eugenol cement (EBA cement) (Stailine, Staident, Middlesex, England; one trial) and (iii) gold leaf (one trial) appeared to be better than amalgam retrograde (root-end)-filling. Finally, gutta-percha retrograde (root-end)-filling appears to be less effective than amalgam (one trial) and Retroplast with ytterbium trifluoride is better than Retroplast with silver, when they are both used with Gluma as bonding agent (one trial).
Conclusions For the highest level of evidence (RCT) retrograde (root-end)-filling with glass ionomer cement is almost as effective as amalgam. However, there was a significant caveat as there were only two RCTs. At the next highest level of evidence (CCT), and given the additional caveat that there was only one controlled trial for each material, retrograde (root-end) EBA cement, composite with Gluma and gold leaf, as well as orthograde gutta-percha, may be more effective than retrograde (root-end) amalgam filling. In conclusion, these results suggest that additional validating CCTs and RCTs are needed.