Please activate JavaScript!
Please install Adobe Flash Player, click here for download
ePaper created 2016-01-20, 13:53:08 | version 1.38.0
I 15 studies _ comparison of three methods of therapy I roots1_2015 tient sample, but accounted for 65.5% of EX. The EX rate in the higher socio-economic groups was more favourable in relation to their percentage of the pa- tient sample. Thus, the patient sample in this study confirms the finding in the literature45 that socio- economic status does influence loss of teeth: the lower the status, the sooner EX is performed. According to Ng et al.,46 predictors of increased lossofteethwerepreoperativepathology,toothfrac- ture and restoration with a post. The last had a 2.6 times greater EX rate. The authors found the highest EXrate(9.9%)afterprimaryRCTinthemaxillarypre- molars. In the course of a significantly longer follow- upperiod,thepresentstudyfoundthehighestEXrate in the maxillary premolars (20.6%) and the lowest in the maxillary anterior teeth (12.3%). WithrespecttoprimaryandsecondaryRCT,statis- ticallysignificantdifferencesregardingdevelopment ofFailure2andthenumberofEXswerenotfound.Af- terfive(ten)years,93.1%(84.9%)didnotexhibitFail- ure 2 after primary RCT, nor did 95.2% (87.1%) after secondary RCT. However, acute exacerbations after nsRCT developed more often after secondary RCT (17.6%, n = 21) than after primary RCT (12.1%, n = 49). Five (ten; 15) years after RCT, the EX survival rate was 88.9% (72.2%; 57.1%) after nsRCT, 88.7% (76.8%;69.6%)afterRERand90.5%(80.6%;70.6%) afterTR.AcomparisonofnsRCTandTRshowedasta- tisticallysignificantdifferenceofp=0.029.Nostatis- tically significant difference was noted between nsRCT and RER (p= 0.104). After five years, the pres- ent study showed the same EX rate of 11% as Salehrabi and Rotstein.9 Also Ng et al.46 noted no dif- ference in EX rate between primary and secondary RCT after two to four years (4.6% and 4.8%, respec- tively).Painandtheinsertionofacastpostledtoasta- tistically significant loss of teeth. Overfilling had no effectinthefirst22monthspost-RCT,butdidlateron. In another study, Ng et al.5 found that flush RCFs and those that were too short in a primary RCT led to the samesuccessrateprovidedthattherewasnoAPpre- RCT. However, they attached special importance to RCF quality: a success rate of 82.9% with good qual- ityRCFandof61.1–64.2%withpoorqualityRCF.Inthe caseoftheFailure1rate,thepresentstudydidnotshow any difference with regard to RCF quality. The failure difference (development of Failure 2) between good andpoorqualityRCFwashighlystatisticallysignificant (p < 0.001). The Failure 2 rate was more than double withpoorqualityRCFcomparedwithgoodqualityRCF. Ten years after RCT, 87.6% of teeth with good qualityRCFand70.5%ofteethwithpoorqualityRCF did not exhibit Failure 2. In the present study, rela- tivelyfewerteethwereextractedafteroverfillingver- sus underfilling and RCF of length 0 to –1. The mandibular premolars featured the lowest Failure 2 rate (9.5%) and the mandibular incisors the highest (21.8%), followed by the maxillary lat- eral incisors (16.3%). The high Failure 2 rate for the mandibularincisorsmaybeduetothefactthatthese teeth often have two canals and that the filling of a second canal might not have been registered. The Failure 2 rate was as follows for the maxillary lateral incisors:17.9%fornsRCT,18.9%forRERand11.4% for TR. The higher Failure 2 rate for the maxillary lat- eral incisors might be attributed to the anatomic situationoftheroottippointinginthepalataldirec- tionandthusamorecomplicateddiagnosis,aswell astotheincreasedpresenceofascar,especiallyaf- ter RER, as mentioned by Friedman23 and Kirchen.27 Kerekes47 found that the lowest success rate for all tooth locations was for the maxillary lateral inci- sors:43%afterRCTbypractitionersand68%after RCT by students. Kerekes47 specified a general suc- cess rate of 60% for practitioners and of 82% for students. It is important to note that TR as therapy for pain isjudgedinthisstudyassuccesslimiting.Possiblefol- low-uptherapiesinacuteexacerbationshavenotof- ten been described in the endodontic literature. Per- haps,await-and-seeattitudeisoftenadoptedand/or analgesics are administered. Instead of immediately reacting with a therapeutic measure (EX, RER, TR) in the case of pain, waiting might have led to pain re- leaseanyway,thusimprovingthementionedRCTsur- vival and failure results. Itisimportanttonotethatthenumberofremain- ing teeth was ultimately higher than might be as- sumed by the failure rate, as failure did not necessar- ily mean loss of teeth; 105 cases remained in situ af- ter RER, TR or RV, starting a new survival cycle on the day of re-intervention. Table 5_Survival rate in relation to Failures 1 and 2, depending on the quality of the RCF. Table 6_Survival rate in relation to Failure 2, depending on restoration type. Years Survival rate (%) Quality 1 Quality 2 5 95.0 86.5 10 87.6 70.5 15 81.3 61.8 Years Survival rate (%) Filling Crown Post:no Post:yes 5 89.3 97.3 96.4 10 83.1 92.4 77.8 15 74.7 86.7 70.7 Table 5 Table 6 595.086.5 1087.670.5 1581.361.8 589.397.396.4 1083.192.477.8 1574.786.770.7