applied sciences Article The Influence of Hard- and Software Improvement of Intraoral Scanners on the Implant Transfer Accuracy from 2012 to 2021: An In Vitro Study Alexander Schmidt 1,*, Maximiliane Amelie Schlenz 1 , Haoyu Liu 1, Holger Sebastian Kämpe 2 and Bernd Wöstmann 1 1 Dental Clinic—Department of Prosthodontics, Justus Liebig University, Schlangenzahl 14, 35392 Giessen, Germany; maximiliane.a.schlenz@dentist.med.uni-giessen.de (M.A.S.); haoyu.liu@dentist.med.uni-giessen.de (H.L.); bernd.woestmann@dentist.med.uni-giessen.de (B.W.) 2 Dental Practice, Rommelstr. 1, 35708 Haiger, Germany; holger.kaempe@gmail.com * Correspondence: alexander.schmidt@dentist.med.uni-giessen.de; Tel.: +49-641-9946150 Abstract: This study aimed to investigate the transfer accuracy (trueness and precision) of three different intraoral scanning families using different hardware and software versions over the last decade from 2012 to 2021, compared to a conventional impression. Therefore, an implant master model with a reference cube was digitized and served as a reference dataset. Digital impressions of all three scanning families (True definition, TRIOS, CEREC) were recorded (n = 10 per group), and conventional implant impressions were taken (n = 10). The conventional models were digitized,  and all models (conventional and digital) were measured. Therefore, it was possible to obtain the  deviations between the master model and the scans or conventional models in terms of absolute Citation: Schmidt, A.; Schlenz, M.A.; three-dimensional (3D) deviations, deviations in rotation, and angulation. The results for deviations Liu, H.; Kämpe, H.S.; Wöstmann, B. between the older and newer scanning systems were analyzed using pairwise comparisons (p < 0.05; The Influence of Hard- and Software SPSS 26). The absolute 3D deviations increased with increasing scan path length, particularly for Improvement of Intraoral Scanners the older hardware and software versions (old vs. new (MW ± SD) True Definition: 355 ± 62 µm on the Implant Transfer Accuracy vs. 483 ± 110 µm; TRIOS: 574 ± 274 µm vs. 258 ± 100 µm; and CEREC: 1356 ± 1023 µm vs. from 2012 to 2021: An In Vitro Study. Appl. Sci. 2021, 11, 7166. https:// 110 ± 49 µm). This was also true for deviations in rotation and angulation. The conventional doi.org/10.3390/app11157166 impression showed an advantage only regarding the absolute 3D deviation compared to the older systems. Based on the data of the present study, the accuracy of intraoral scanners is decisively Academic Editors: Paola Gandini and related to hardware and software; though, newer systems or software do not necessarily warrant Andrea Scribante improvement. Nevertheless, to achieve high transfer accuracy, regular updating of digital systems is recommended. The challenge of increasing errors with increasing scan paths is overcome in the Received: 25 June 2021 most recent systems. The combination of two different scanning principles in a single device seems Accepted: 1 August 2021 to be beneficial. Published: 3 August 2021 Keywords: dental implants; digital dentistry; dental impression technique; dimensional measurement Publisher’s Note: MDPI stays neutral accuracy; intraoral scanner with regard to jurisdictional claims in published maps and institutional affil- iations. 1. Introduction Intraoral scanners (IOSs) have demonstrated ceaseless development since their in- troduction in 1985; therefore, currently, a wide range of digital scanners are available for Copyright: © 2021 by the authors. a dental practice, and the use of IOSs is part of the daily practice routine for a continu- Licensee MDPI, Basel, Switzerland. ously increasing number of dentists [1,2]. Numerous studies on IOS are available, most This article is an open access article distributed under the terms and dealing with different aspects of accuracy, some addressing handling, and a few focusing conditions of the Creative Commons on the further development and implementation of digital processes [3–7]. However, all Attribution (CC BY) license (https:// these aspects are necessarily related to the capabilities of the actual scanners used in this creativecommons.org/licenses/by/ study [8]. Although improvements have occurred over the years, the underlying reasons 4.0/). for the differences are difficult to distinguish as they may be related to the study setup, Appl. Sci. 2021, 11, 7166. https://doi.org/10.3390/app11157166 https://www.mdpi.com/journal/applsci Appl. Sci. 2021, 11, 7166 2 of 13 the operator’s experience, or the scanners themselves. To the best of our knowledge, no study has compared different generations of scanner families in an identical study setup over the years. For each of the three different scanning principles (optical triangulation technique, active wavefront sampling, and confocal laser scanning systems), a typical scanner is included. As only a single scanner family uses active wavefront sampling, this family is also included, although the respective manufacturer will discontinue the scanner and the future of the system is unclear. A large number of studies have shown that various factors influence the accuracy of intraoral scans. To date, a lack of calibration [9], the scanning path [10,11], and the users themselves [12] were identified as potentially influential factors. While IOS could already reach or even exceed the accuracy of conventional impressions for single teeth [13], the situation, for a long time, with regard to impressions of natural teeth, especially across the quadrant, was that IOS could not reach the level of accuracy of conventional impressions [14,15]. However, in more recent studies, it was demonstrated that IOS impressions within a quadrant and even beyond could achieve even better results than with conventional impression methods [3,16]. With regard to implant impressions, the results of a previous clinical study even showed similar results between conventional and digital impression methods when taking impressions of maxillary situations or partially edentulous jaw sections [4]. Comparable results were also obtained in other studies [17,18]. Although IOS are constantly being developed and improved, only a few studies [19–21] are available where different software versions were examined and described as potentially influencing the transfer accuracy of IOS. However, within one study, only two different software versions of a scanner family were investigated with regard to the accuracy of single tooth preparations. It was found that the software version can have an influence on the result of the transfer accuracy [19]. In a further study, the influence of different parameters during the production of crowns was investigated. Two different software versions of a scanner were also used [20]. The most recent study on the influence of differ- ent software versions was investigated in relation to the accuracy of different restorative materials [21]. However, none of these studies investigated the influence on the transfer accuracy of implants. Furthermore, the transfer accuracy of implants by intraoral scanners is of specific interest, since implants have a tenfold lower mobility compared to natural teeth which requires an enormously high transfer accuracy from the oral situation to the model situation [22,23]. For this reason, an implant model setup with a corresponding reference key offers excellent possibilities for standardization over the years, due to the fact that the implant model structures are precisely prefabricated and remain dimensionally stable over a long period of time. Thus, implant models represent identical basic situa- tions. Therefore, in order to eliminate possible external influences such as different study setups, the influence of scanbodies, or measuring strategies [4,16,24–26] in the present study, two investigators assessed the transfer accuracy (trueness and precision) of three different IOS families using different hardware and software versions from 2012 to 2021 and compared them to a conventional impression (CI) on the same implant model over a period of ten years. According to ISO 5725-1, mean values for the deviations between the IOS results and the master model describing trueness and standard deviation describing precision for the different scanners and the CI [27]. The null hypothesis tested was as follows. There are no differences in the transfer accuracy for different IOSs with different hardware and software versions. 2. Materials and Methods To simulate a clinically close setup, a partially edentulous maxillary model was used as an implant master model (IMM). The model shows a typical patient situation with one interrupted and one unilaterally shortened arch. The base plate (100 × 100 mm) of the model is made of stainless steel, into which four steel tubes for implant placement (positions 16, 14, 25, and 26 of the Federation Dentaire Internationale [FDI]) were inserted. Appl. Sci. 2021, 11, x FOR PEER REVIEW 3 of 14 2. Materials and Methods To simulate a clinically close setup, a partially edentulous maxillary model was used as an implant master model (IMM). The model shows a typical patient situation with one interrupted and one unilaterally shortened arch. Appl. Sci. 2021, 11, 7166 The base plate (100 × 100 mm) of the model is made of stainless steel, into which3 offo1u3r steel tubes for implant placement (positions 16, 14, 25, and 26 of the Federation Dentaire Internationale [FDI]) were inserted. FFoouurrs stteeeellt tuubbeessf foorri mimpplalannttp plalacceemmeenntt( (ppoossitiitoionnss1 166, ,1 144, ,2 255, ,a anndd2 266o offt htheeF Feeddeerraatitoionn DDeennttaaiirreeI Inntteerrnnaattiioonnaallee [[FFDDII]]))w weerreei ninsseerrtteeddi nint hthees tsataininlelesssss tseteeel lb baasesep plalatete( 1(100× × 1100 ccmm)) oofft thheeI IMM,,a annddS Sttrraauummaannnn RRNN SSttaannddaarrddP Plluuss iimmppllaannttss ((SSttrraauummaannnn,, FFrreeiibbuurrgg,,G Geerrmmaannyy)) wweerreea addhheessiviveelylyl uluteteddi nint htheet utubbeess( 1(144m mmml elennggthth, ,4 4.8.8m mmmd diaiammeeteter;r;G GaalvlvaannooA AGGCC-C-Ceemm aaddhheessivivee, ,W Wieielalanndd-D-Denentatla,lW, Würüzrbzubrugr,gG, Geremrmanayn)y. )T. wTowroe freerfeenrecnescecsu cbuebs e(Rs C(R,Cp,e rppeernpdenicduilcaur- tloare atoc heaocthh eort)hwere) rweeinres einrtseedrteind FinD FIDpIo psiotisoitniosn1s8 1a8n adn2d3 2.3T. hTeheb absaiscics tsrtuructcuturereo of fa ap paarrtitaialllyly eeddeennttuulolouussu upppeerrw wasasm modoedlelelldedo fopf ipnikn-kco-cloorloedremd emtheythl yml emtheatchrayclraytela(tPea (lPaaXlparXepssr,eKssu, lKzeurl,- Hzearn, aHua, nGaeurm, Gaenrym; Fanigyu; rFeig1u).re 1). FFiigguurree1 1. .I Imppllaanntt maasstteerr mooddeell( (IIMM))w witithht twwoor reeffeerreenncceec cuubbeessa annddfi fninaal ls seetutuppw witihthi ninsseertretedds sccaann bbooddieiess( (FFDDII1 166, ,1 144, ,2 255, ,2 266).). TTood deetetermrminineet htheeim impplalnatnpt opsoistiiotinosn,st,h tehIeM IMMw wasads idgiitgiizteizdeuds uinsginagc ao ocordoirndaitneamtee maseuars-- iungrinmga mchainchei(nCeM (CMM, TMh, oTmheomRaep Rida,pTidh,o mTheopmreec pisrieocni,siMone,s sMele,sGseelr,m Gaenrym, anccyu, racccyu2ra.2cyµ m2.)2 wµimth) twheitcho rtrhees pcoonrrdeisnpgonsodfitnwga rseofMtweatrroe loMge(tMroelotrgo l(oMgiectrGorlooguipc , GMreoyulpa,n ,MFeraynlacne,) .FTrahnecree)-. fTorhee,rtehfeoruep, ptheer usuprpfaerc esuorfftahcee ionfd tihveid iunadlivsicdaunablo sdciaensbwoedrieest owuecrhee dtoauncdhedde fiannded daesfianepdla anse a. Tphlaenne, .t hTehelant,e trhael slautrefraacle ssuorffatchees socfa tnhbeo sdciaensbwoderieest wouecrhe etdouacnhdedd eafinnde ddeafisnceydl iansd ceyrlsin. dTehres. kTnhoew knnloewngnt hleonfgtthhe osfc tahneb socdainesbomdaidese mit apdoes siitb pleostositbrlaen tsof etrrathnesfperla tnhee opflathnee soufr tfhacee stuorftahcee itmo ptlhaen ti–mapbulatnmt–eanbtuintmteerfnatc einpteorifnatcbe ypmoienatn bsyo fmaepaanrsa ollfe las hpiafrt.alTloel dsehtiefrtm. Tinoe dtehteerlemnignteh tohfe tlheengscthan obfo thdeie sscpanrebcoisdeileys, pthreecyisweleyr,e thalesyo wmeeraes aulrseod mweaitshutrheed CwMithM th(Te hCoMmMe R(Tahpoidm, eT Rhoapmide , pTrhecoimsioen p, rMeceisssieoln, ,G Meremssaenly, )Gdeurmrinagnyp)r edluimriinnga rpyrteelsimts.inTahrey dteefistnse. dThpela dneefoinnetdh epslacanneb oond itehse asscawneblloadsietsh easd wefienlli taosn tohfet dheefcinyliitnodne orfa tlhsoe mcyalidnedietrp aolsssoi bmleatdoed iet tpeormssiinbelet htoe danegteurlmatiinoen tohfe tahnegsuclaantbioond oiefs t.hTeh secasnabmoediaepsp. Tlihese tsoamthee arpoptaltieiosn t,ow thhei crhotcaotiuolnd, bwehdicehfi ncoeudldon beth deebfianseids oofn atnhoet bhaesrifls aotf saunrofathceero fnlatth seuorfuatceer osunr tfhaece oouftethr esucryflainced eorf othfeth ceylsicnadnebro odfy t.he scanbody. Based on the reference cube (RC; FDI 18) on the IMM, a coordinate system was defined as reference. Scan data were exported as a standard tessellation language (STL) file format, serving as a reference file. Four intraoral scanbodies (ISBs; N1410, Medentika, Hügelsheim, Germany) were screwed in the implants (15 Ncm) of the IMM for the digital impressions. The H1410 ISB consists of a cylindrical titanium base and a flattened plane in the upper part. Scans were performed using three different IOS families: True Definition Scanner (3M, St. Paul, MN, USA), which is based on active wavefront sampling; the TRIOS Appl. Sci. 2021, 11, 7166 4 of 13 family (3Shape, Copenhagen, Denmark) based on confocal laser scanning microscopy; and the Sirona CEREC Omnicam/Primescan family (Sirona, Bensheim, Germany) with an optical triangulation technique. Primescan additionally uses confocal microscopy [28,29] as a second acquisition principle. The scanners used in the corresponding software versions are listed in Table 1. Table 1. Intraoral scanning systems with corresponding software versions used in the present study. Scanner Family Type Software Version Release Date Label True Definition scanner (Cart version) 4.0.3 2013-04 TD_4.1 True Definition True Definition scanner (Cart version) 5.4 2018-07 TD_5.4 Scanner True Definition scanner (Portable version) 5.4 2018-07 TDpb_5.4 TRIOS II 2013-01 2013-01 TR2 TRIOS TRIOS 4 19.2.4 2020-12 TR4 CEREC Omnicam 4.2.1.61068 2012-04 OC_4.2 CEREC CEREC Omnicam 4.6.1.152739 2018-05 OC_4.6 CEREC Primescan 5.1.0.190461 2020-05 PS Two trained and calibrated examiners (H. L. and H. S. K.) performed 10 full-arch scans using the calibrated scanners and followed the scanning paths, recommended by the different manufacturers, which were as follows: scan started at the occluso-palatal surfaces of the right molar in the maxillary (including the RCs), moved towards the second quadrant constantly including the palatal surfaces, then again to the RCs, and to the occlusal surfaces, returning to the buccal side. It was of particular importance that both examiners had an identical level of training in scanning. Both were in the same period after their exams and were trained on all devices. If a single examiner had performed all the scans, it could be assumed that the knowledge gained in scanning over the long period from 2012 to 2021 had an influence on the results. The analyses were based on evaluation methods already known and used in a previous study [26]; for this purpose, all scan data were first exported to a standard STL file format. For conventional impressions (n = 10), the open-tray technique was used [30,31]. A custom tray consisting of C-Plast (Candulor Dental GmbH, Rielasingen-Worblingen, Germany; thickness 3 mm) with a tubular design around the impression copings (including RCs) was fabricated. Four impression copings (N TR-RN024.8, nt-trading, Karlsruhe, Germany) were fixed into the implants (15 Ncm). To compensate for the laboratory conditions, the impression material (Impregum Penta) was allowed to set for ten minutes (23 ± 1 ◦C temperature, 50 ± 10% relative humidity). Afterwards, impression post screws were loosened, and the impression was removed from the IMM. A total of ten impressions were obtained. Laboratory analogs were repositioned on the impression posts (N51, nt- trading, Karlsruhe, Germany) and tightened with a torque of 15 Ncm. Using Fujirock EP (GC Corporation, Tokyo, Japan), ten plaster casts were produced and stored under laboratory conditions for seven days. The received STL files were imported into Gom Inspect (Gom, Braunschweig, Ger- many) and aligned to the reference file with the RCs to measure the digital impressions. This made it possible to superimpose the respective coordinate systems within the digital impressions using the reference cuboids. To clearly determine the distances within the digi- tal models, the distances between the reference cuboid and the implant–abutment interface points (IAIPs) were measured in the IMM. This procedure was applied to both the digital and the conventional models. Then,√the absolute linear displacement (∆R) of the IAIPsfor each implant position from the digital and conventional impressions and the reference data set was calculated using ∆R = 2 (x2 − x1)2 + (y2 − y1)2 + (z2 − z1)2. To measure the deviations of rotation and angulation, planes and cylinders were constructed at the respective scan bodies. This made it possible to compare the same planes and cylinders in Appl. Sci. 2021, 11, x FOR PEER REVIEW 5 of 14 Karlsruhe, Germany) and tightened with a torque of 15 Ncm. Using Fujirock EP (GC Cor- poration, Tokyo, Japan), ten plaster casts were produced and stored under laboratory con- ditions for seven days. The received STL files were imported into Gom Inspect (Gom, Braunschweig, Ger- many) and aligned to the reference file with the RCs to measure the digital impressions. This made it possible to superimpose the respective coordinate systems within the digital impressions using the reference cuboids. To clearly determine the distances within the digital models, the distances between the reference cuboid and the implant–abutment in- terface points (IAIPs) were measured in the IMM. This procedure was applied to both the digital and the conventional models. Then, the ab(s𝑥ol−ut𝑥e )li2n e+ar ( d𝑦is−p𝑦lac)2em +e n(t𝑧 (Δ−R𝑧) )o2f the IAIPs for each implant position from the digital and conventional impressions and the reference data set was calculated using ΔR = . To Appl. Sci. 2021, 11, 7166 measure the deviations of rotation and angulation, planes and cylinders were construc5toefd1 3 at the respective scan bodies. This made it possible to compare the same planes and cyl- inders in the master model and digital models. The corresponding distances and angles arthe eshmoawstne rinm Foigduelrea n2d. digital models. The corresponding distances and angles are shown in Figure 2. FiFgiugurer e2.2 S.chSecmheamtica rtiecprreespernetsaetniotant ioofn thoef mtheeasmureeads uarbesdolaubtes othlurteee-tdhirmeee-ndsiimoneanls dioisntaalncdeiss t(aAn)c,e rsot(aA-), tiroontsa t(iBo)n, san(Bd) ,aanngdulaantigounlsa t(iCo)n ws (iCth)iwn itthhei nimthpelainmtp mlaansttemr amstoedreml (oIdMeMl ()I.M M). To measure the IAIPs, rotation, and angulation of the gypsum models, four scan bodTieos m(Nea1s4u1r0e, tMhee dIAenIPtisk, ar,oHtaütigoenl,s ahnedim a,nGguelramtiaonny o)fw theer egytipgshutemn emdoidnetlhs,e foimurp slcaannts bwodit-h ieas t(oNrq1u41e0o, fM15edNecnmtikaan, dHmügeealssuhreeidmu, sGinegrmaaCnMy) Mwe(RreA tPigIDht,eTnheodm ine, tMhee sismelp, lGanetrsm wanityh) ato toervqaulue aotfe 1t5h Ne cambs aonludt em3eDasudrisetda nucseinsgb ae tCwMeeMn (tRhAe PIAIDIP, sThaonmd eR, CM.eTsosealv, Goiedrmerarnoyrs) ttoh aetvacal-n uraetseu tlhtef raobmsoelvueten 3tDhe dsimstaalnlecsets vbiebtrwateioenn sthoef tIhAeIPCsM aMndd RuCe.t Toom aavnouidal emrraonrisp tuhlaatt icoanns raensdultto frionmcr eeavseenth tehep rsemciasilolensto fvtibhreamtioeanssu oref mtheen tCs,MthMe fdoulleo wtoin mgamneuaaslu mreasnwipeurelattaikoenns. aAndp rtoog rinam- crweaassec trheaet pedretcoissiotann odfa trhdeiz me eaansduraeumtoemntast,e ththee fomlleoawsuinrgem meenatspurroecs ewsserfoe rtaakllecna. sAts pursoignrgatmhe wMase tcrroelaotgeds otoft wstaanred(aMrdeitzreo laongdi caGutroomupat,eM theey lmane,aFsurarnemcee).nTt hperopcreosgs rfaomr ailnl cclausdtse udssinergi etsheo f Mperterdoelofign esdoftmweaarseu (rMemeternotlocgoimc Gmraonudps, (MTUeyRlaNnI,N FGranPcOe)I.N TTh,eC pYrLoIgNraDmE Rin,cPluLdAeNd Ese)rfioers tohfe pCreMdeMfinweidt hmseuabssuerqeumenent td acotamemvaalnudasti o(TnU. WRNithINinGt hPeOpIrNogTr, aCmY,LthINe DmEoRd,e lPsLwAeNreEm) feoars uthreed 10 times, and the arithmetic mean was calculated. This procedure was performed 10 times. Statistical analyses were performed using SPSS version 26 (IBM, Chicago, IL, USA). The results for the deviations were analyzed using the Mann–Whitney and Kruskal–Wallis tests. As the data in some cases were not normal distributed, the results were reported using boxplot format. Though the not normal distributed results had limited relevance, they had to be considered. Mean values and standard deviations are presented in Table 2 to provide additional information and an overview over trueness and the precision according to ISO 5725-1. Appl. Sci. 2021, 11, 7166 6 of 13 Table 2. Statistical analysis of the implant positions (FDI: 16, 14, 24, 26) and impression methods (TD_4.1: True Definition scanner (Cart version) 4.1; TD_5.4: True Definition scanner (Cart version) 5.4; TDpb_5.4: True Definition scanner (Portable version) 5.4; TR2: TRIOS II; TR 4: TRIOS 4; OC_4.2: CEREC Omnicam 4.2.1.61068; OC_4.6: CEREC Omnicam 4.6.1.152739; PS: CEREC Primescan 5.1.0.190461) for trueness and precision according to ISO 5725. Mean ± standard deviations [µm]) of the three-dimensional deviations, deviations in rotation, and angulation. Significant differences (p < 0.05) are highlighted in bold type. Impression Method p-Value Trueness/Precision (Mean [µm] ± Standard Deviation [µm]) Implant Position Hardware/Software- Version 16 14 25 26 (Old—New) <0.001/0.672 <0.001/0.010 <0.001/0.024 0.013/0.135 TD_4.1—TD_5.4 (0.047 ± 0.009– (0.047 ± 0.014– (0.258 ± 0.052– (0.355 ± 0.062– 0.101 ± 0.013) 0.185 ± 0.035) 0.515 ± 0.103) 0.483 ± 0.110) <0.001/0.082 <0.001/0.009 <0.001/0.007 0.002/0.010 TD_4.1—TDpb_5.4 (0.047 ± 0.009– (0.047 ± 0.014– (0.258 ± 0.052– (0.355 ± 0.062– 0.115 ± 0.028) 0.192 ± 0.069) 0.597 ± 0.120) 0.632 ± 0.184) 0.006/0.004 <0.001/0.009 0.002/0.035 0.001/0.071 Three-dimensional TR2—TR4 (0.089 ± 0.036– (0.335 ± 0.105– (0.516 ± 0.242– (0.574 ± 0.274– Deviations 0.044 ± 0.011) 0.092 ± 0.043) 0.214 ± 0.072) 0.258 ± 0.100) <0.001/0.863 <0.001/0.002 <0.001/<0.001 0.001/<0.001 OC_4.2—OC_4.6 (0.282 ± 0.058– (0.747 ± 0.262– (1.260 ± 0.889– (1.356 ± 1.023– 0.154 ± 0.039) 0.256 ± 0.092) 0.335 ± 0.173) 0.370 ± 0.195) <0.001/0.163 <0.001/<0.001 <.001/<0.001 <0.001/<0.001 OC_4.2—PS (0.282 ± 0.058– (0.747 ± 0.262– (1.260 ± 0.889– (1.356 ± 1.023– 0.038 ± 0.014) 0.085 ± 0.024) 0.115 ± 0.053) 0.110 ± 0.049) <0.001/0.099 <0.001/0.099 0.001/0.605 0.821/0.435 TD_4.1—TD_5.4 (0.067 ± 0.044– (0.031 ± 0.029– (0.108 ± 0.073– (0.152 ± 0.090– 0.312 ± 0.078) 0.237 ± 0.108) 0.335 ± 0.108) 0.143 ± 0.065) <0.001/0.123 0.001/0.001 0.004/0.004 0.005/0.012 TD_4.1—TDpb_5.4 (0.067 ± 0.044– (0.031 ± 0.029– (0.108 ± 0.073– (0.152 ± 0.090– 0.339 ± 0.076) 0.211 ± 0.182) 0.640 ± 0.354) 0.494 ± 0.266) 0.324/0.026 0.012/0.009 0.012/<0.001 0.008/0.004 Rotational TR2—TR4 (0.161 ± 0.125– (0.349 ± 0.233– (0.709 ± 0.491– (0.067 ± 0.044– Deviations 0.084 ± 0.058) 0.139 ± 0.073) 0.206 ± 0.131) 0.339 ± 0.076) 0.021/0.718 0.405/0.003 0.001/0.008 0.006/0.001 OC_4.2—OC_4.6 (0.218 ± 0.138– (1.567 ± 2.414– (1.307 ± 0.877– (1.083 ± 0.814– 0.418 ± 0.184) 0.404 ± 0.247) 0.241 ± 0.272) 0.313 ± 0.221) 0.130/0.030 0.008/0.002 0.002/0.001 0.001/<0.001 OC_4.2—PS (0.218 ± 0.138– (1.567 ± 2.414– (1.307 ± 0.877– (1.083 ± 0.814– 0.122 ± 0.083) 0.131 ± 0.088) 0.123 ± 0.067) 0.123 ± 0.070) 0.471/0.724 <0.001/0.681 <0.001/0.525 <0.001/0.638 TD_4.1—TD_5.4 (0.052 ± 0.047– (0.251 ± 0.119– (0.194 ± 0.082– (0.101 ± 0.092– 0.058 ± 0.044) 0.541 ± 0.132) 0.515 ± 0.097) 0.453 ± 0.105) 0.006/0.487 <0.001/0.401 <0.001/0.072 <0.001/0.210 TD_4.1—TDpb_5.4 (0.052 ± 0.047– (0.251 ± 0.119– (0.194 ± 0.082– (0.101 ± 0.092– 0.118 ± 0.041) 0.526 ± 0.089) 0.601 ± 0.162) 0.477 ± 0.111) 0.290/0.090 0.004/0.005 <0.001/0.008 0.015/0.007 Angulation TR2—TR4 (0.219 ± 0.146– (0.685 ± 0.352– (0.567 ± 0.238– (0.374 ± 0.224– Deviations 0.139 ± 0.074) 0.299 ± 0.100) 0.130 ± 0.069) 0.159 ± 0.083) 0.096/0.007 0.705/0.008 0.059/0.010 0.054/0.010 OC_4.2—OC_4.6 (0.318 ± 0.296– (0.569 ± 0.658– (0.663 ± 0.448– (0.531 ± 0.399– 0.121 ± 0.104) 0.236 ± 0.087) 0.275 ± 0.216) 0.183 ± 0.139) 0.151/0.005 0.019/0.003 0.023/<0.001 0.002/<0.001 OC_4.2—PS (0.318 ± 0.296– (0.569 ± 0.658– (0.663 ± 0.448– (0.531 ± 0.399– 0.120 ± 0.092) 0.055 ± 0.039) 0.152 ± 0.114) 0.053 ± 0.031) Appl. Sci. 2021, 11, x FOR PEER REVIEW 7 of 14 0.130/0.030 0.008/0.002 0.002/0.001 0.001/<0.001 Appl. Sci. 2021, 11, 7166 OC_4.2—PS (0.218 ± 0.138– (1.567 ± 2.414– (1.307 ± 07.8o7f71–3 (1.083 ± 0.814– 0.122 ± 0.083) 0.131 ± 0.088) 0.123 ± 0.067) 0.123 ± 0.070) 0.471/0.724 <0.001/0.681 <0.001/0.525 <0.001/0.638 3. Results TD_4.1—TD_5.4 (0.052 ± 0.047– (0.251 ± 0.119– (0.194 ± 0.082– (0.101 ± 0.092– The results for the absolute 3D deviation0s.a0n5d8 ±th 0e.0r4o4ta) tio0n.a5l4a1n ±d 0a.1n3g2u)l ati0o.n51d5e ±v i0a.t0i9o7n)s 0.453 ± 0.105) for each implant position and the IOS are p0r.0e0se6n/0t.e4d87i n Fi