Accuracy of the Provisional Prosthesis Scanning Techniqueversus a Conventional Impression Technique on Completely Edentulous Arches

Аннотация

Purpose:Inthisstudy,weaimedtocomparethemarginalfitoffixeddentalrestorations fabricatedwiththeprovisionalprosthesisscanningtechniqueversusaconventionalimpression techniqueandtodeterminetheeffectofbothvariablesontheaccuracyoutcome. Materialsand Methods:Twelveidenticalpolyurethaneedentulousmaxillarymodelswereequallydividedintotwo groups:control(conventionalimpressiongroup)andtest(provisionalprosthesisscanninggroup). Afterobtainingtheimpressionusingtheabove-mentionedmethodsandfurtherpreparingthefinal prosthesis,thepassivityofthemetalframeworkprosthesiswascheckedusingasinglescrewtest,i.e., Citation: Lee,C.; onlyonescrewwasfixedontheterminalrightabutment,andallotherswereempty.Themarginal Dusmukhamedov,S.;Fang,Y.-Q.; fitofthefinalprostheticframeworksscrewedontotheimplantsontheterminalleftabutmentwas Jeong,S.-M.;Choi,B.-H.Accuracyof measuredattheterminalrightsightbyperiapicalradiographsobtainedimmediatelyaftermetal theProvisionalProsthesisScanning frameworkplacementsinbothgroups.Themediansderivedfromthetwogroupswerecompared TechniqueversusaConventional usingtheMann–Whitneytest.Inalltests,ap-value<0.05indicatedstatisticalsignificance.Results: ImpressionTechniqueonCompletely EdentulousArches.Appl.Sci.2021, In the provisional prosthesis scanning group, the median marginal fit discrepancy was 170 µm 11,7182. https://doi.org/10.3390/ (range120–190). Intheconventionalimpressiongroup,themedianmarginalfitdiscrepancywas app11167182 1080µm(range1040–1100).Therewasasignificantdifferenceintheimplant-frameworkmarginal gapfitdiscrepancybetweenthesetwogroups.Conclusion:Prosthesesfabricatedwiththeprovisional AcademicEditor:AntonioScarano prosthesisscanningtechniquearesignificantlymoreaccuratethanthosefabricatedwithconventional impressiontechniques. Received:13July2021 Accepted:2August2021 Keywords:accuracyofimplantprosthesis;provisionalprosthesisscanning;conventionalimplant Published:4August2021 impressions;edentulousarch Publisher’sNote:MDPIstaysneutral withregardtojurisdictionalclaimsin publishedmapsandinstitutionalaffil- 1. Introduction iations. Inimplantdentistry,passivefittingofanimplant-supportedfixedprosthesisisessen- tialtoensurecorrectandsuccessfuloralrehabilitation,especiallyincasesofimmediate placementandimplantloading[1–3]. Thereareseveralclinicalandlaboratoryvariables that affect the accuracy of an implant cast [3], but the most significant factor is the im- Copyright: © 2021 by the authors. pressionprocedure. Heckmannetal.[4]reportedthat50%oferrorsintermsofaccuracy Licensee MDPI, Basel, Switzerland. arebecauseoftheimpressiontechniqueperformedbytheclinicians,whiletheremaining This article is an open access article 50% are related to inaccurate laboratory procedures. The development of CAD/CAM distributed under the terms and systemshasresultedinnewandmoreaccuratemethodsthathavereplacedconventional conditionsoftheCreativeCommons techniques,particularlyinimplantprostheticdentistry. Inthedigitalworkflowforfull- Attribution(CCBY)license(https:// archfixedscrew-retainedrestoration,finalrestorationscanbefabricatedbycorrelation creativecommons.org/licenses/by/ 4.0/). techniques[5–9]. Severalstudieshaverecommendedtheadvantageofdigitalimpression Appl.Sci.2021,11,7182.https://doi.org/10.3390/app11167182 https://www.mdpi.com/journal/applsci Appl.Sci.2021,11,7182 2of10 methodsascomparedwithconventionalmethods[4,10–12],however,therearerelatively fewstudiesreportingontheprecisionoffinalprosthesesfabricatedbydigitalworkflowin edentulouspatients. Themarginalfitofafinalprosthesisisoneofthemostimportantfactorsforquality assessment of successful prosthetic treatment [11–15]. Numerous studies have evalu- ated the value of passive fit using multiple methods to demonstrate the importance of this point [16–18]. A misfit at the implant-abutment junction results in complications, includingscrewloosening/fracture,ceramicveneerfracture/wear/chipping,andcrestal boneloss[2,19–29]. Hence,attemptsshouldbemadetoensurethatanaccuratemastercast isproducedtogenerateanaccuratelyfittingimplant-supportedfixedfinalprosthesis. Theroleofanimplantandfinalprosthesisinterconnectionontheaccuracyofimplant castsgeneratedwithprovisionalprosthesisscanningtechniqueforedentulousjawshas still not been fully investigated. Thus, additional studies are necessary to evaluate the accuracyofthismethodascomparedwiththoseofconventionaltechniques. Inthisstudy,weaimedtocomparetheaccuracyoffull-archprosthesisframeworks fabricated with the provisional prosthesis scanning versus a conventional impression technique,incompletelyedentulouscases. Thenullhypothesiswasthattheprovisional prosthesisscanningtechniquewouldprovidemoreaccurateframeworksthantheconven- tionalimpressiontechnique. 2. MaterialsandMethods 2.1. ConventionalImpressionGroup Here,weusedapolyurethaneedentulousmaxillarymodelwithasofttissuereplica. Nineimplants(UFII,DIOInc.,Atlanta,GA,USA)wereplacedinthecanine,firstpremolar, second premolar, first molar, second molar, and right upper incisor, thereby creating a master model