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ePaper created 2016-01-20, 13:53:08 | version 1.38.0
16 I I studies _ comparison of three methods of therapy Follow-upradiographswereevaluatedoneyearor more post-RCT, based on the statement by Orstavik42 that the radiographic evaluation would make sense from this point, as 51% of the preoperative lesions will have healed after one year in relation to 76% of the lesions in teeth that were AP-free upon the start of treatment. Molven et al.48 proved that late periapi- cal changes may even occur after ten years or longer, especially after overfilling. This corresponds to the histological findings of Malooley et al.49 that, in the caseofwell-condensedoverfilling,onlydelayedheal- ingoccurs.Theauthorsobservednohistologicalheal- ing in the case of underfilling and poor quality RCF. According to Wood et al.,50 45% of all surgically treatedAPhealswithinonetotenyears,but25%will never heal completely. Grung et al.25 report the heal- ingresults(>78.0%)forRERandperiapicalcurettage as identical; however, it has to be considered that the RER cases included RERs followed by RCF, lowering the RER healing result, with a failure rate of 27.9% versus a failure rate of 4.9% in RER cases with or- thograde RCF. Friedman and Mor26 found a success rate of 37–91% for RER in their survey with asymp- tomatic continuance in function of 86–92%. After primary and secondary RCT with initial AP, the au- thors report a healing rate of 74–86%, as well as a functional survival rate of 91–97%. Barone et al.22 found healing of 84% in RER cases in the age group of over 45 and of 68% in the younger age group. The authors thus considered success in relation to age. Statisticallysignificantdifferencesregardingsuccess orfailureaccordingtoagecouldnotbeproveninthis study. In the present study, almost 70.0% of the RER cases were diagnosed with AP at the start of treat- ment, as were 42.4% of the nsRCT cases and 47.9% of the TR cases. Almost 73.9% of the RER cases (60.8%ofthensRCTand76.4%oftheTRcases)were considered AP-free or healed based on the follow-up radiograph, after an average of 5.9 years. However, it cannotbeexcludedthat,owingtoscarorRCFresorp- tion from the root canal end, some cases were misdi- agnosedasAP.Therefore,theindicatedsuccessrateis in the mid-range of that in the literature on RER: a weighted average healing rate of 70% according to FriedmanandMor26 and81%accordingtoHepworth and Friedman.21 The success rate of each of the three therapy methods compared in this study was 10–20 percentage points higher when there was no initial AP. Aside from the mentioned AP, RCF quality and the restorationtypehadadecisivesignificancefortreat- ment success and survival. Kvist et al.51 report about 13% of apical lesions in restorations without a post and about 16% in those with a cast post. In the pres- entstudy,therewasaFailure2rateof20.1%inteeth thathadreceivedacrownandapost,of5.9%inteeth that had received a crown but no post, and of 13.9% in teeth provided with a filling. The chi-squared test revealed a percentage difference of p < 0.001, indi- cating high statistical significance. It has to be noted thatthecastpostitselfaccountsforfailuretoalesser extent than a technical deficit: via falsa, insufficient RCF (length, homogeneity) before post insertion, as well as preparation of the root canal to too great a depth and thus less remaining RCF. One can learn from the results that an additional TRorRERshouldbetakenintoconsiderationforther- apy of non-vital teeth after orthograde RCF in order toguaranteeabettertreatmentresult.Overfillingwas often followed by acute exacerbation, which might have been treated prematurely in the author’s prac- tice. RER was followed by only 0.5% acute exacerba- tions.RERwaspreferredinthecaseofexistingAPand TR was preferred after overfilling. Failures with a fol- low-up radiograph were diagnosed more frequently after RER compared with the alternative therapies. However,thedifferenceswerenotstatisticallysignif- icant,althoughtheteethtreatedbysimultaneousRCF and RER showed by far the highest rate of apical le- sions at the beginning of RCT. Undertheconditionsattheauthor’spractice,RER and TR were found to be therapy options superior to nsRCT._ Editorial note: A list of references is available from the publisher. Table 7_Drop-out in relation to therapy type. roots1_2015 Dr Robert Teeuwen Berliner Ring 100 52511 Geilenkirchen Germany robteeuwen@t-online.de _contact roots Remaining patients NsRCT RER TR Years n % n % n % 0 570 100.0 756 100.0 464 100.0 1 396 69.5 543 71.8 351 75.6 5 249 43.7 355 47.0 237 51.1 10 89 15.6 180 23.8 110 23.7 15 19 3.3 78 10.3 40 8.6 Table 7 According to Wood et al.,5045% of all surgically 0570100.0756100.0464100.0 139669.554371.835175.6 524943.735547.023751.1 108915.618023.811023.7 15193.37810.3408.6