| Background:This study aimed to optimize the existing scanning protocol to improve the accuracy of intraoral scanning(IOS)technology.The accuracy,chair-side time and patient satisfaction were compared between the optimized protocol and routine protocol,to provide some reference and suggestions for clinicians in selecting appropriate impression methods.Materials and Methods:The design process,clinical workflow,laboratory workflow and practical clinical application of the optimized scanning method were described in the first part.In the second part,sixteen participants with single implant-supported provisional restoration(ISPR)in the maxillary esthetic area were recruited in this study.Two digital impression procedures were performed by making an intraoral scan(TRIOS,3Shape,Denmark)of the gingival contours before and immediately after ISPR removal(IOS+ISPR & IOS-ISPR).The control procedure was formed by fabricating definitive casts from the conventional polyether impression using the ISPR as a customized impression-transfer and making digital impressions of these definitive casts.Both images of paired groups were superimposed using image analysis software(Geomagic Control X).Two-dimensional(2D)and threedimensional(3D)analyses were performed to measure the peri-implant soft-tissue deviation between the reference models and IOS from the groups with or without the ISPR,respectively.Data were presented as the means ± standard deviations.Two-way analyses of variance with post hoc Sidak’s multiple comparisons and paired t-tests were performed for 2D and 3D analyses,respectively.The significance level was set at p<0.05.In the third part,twelve participants were recruited.IOS procedures were performed by making an intraoral scan(TRIOS,3Shape,Copenhagen,Denmark)of the gingival contours with and without ISPR removal.Impression procedures were performed by costumed impression and routine impression.2D and 3D analyses were performed to measure the peri-implant soft-tissue deviation between the reference models and experience models,respectively.Data were presented as the means ± standard deviations.Two-way analyses of variance with post hoc Sidak’s multiple comparisons and paired t-tests were performed for 2D and 3D analyses,respectively.The significance level was set at p<0.05.In addition,chair-side time was recorded on each part of the operation and visual analogue scale was used to record the participants’ comfort.Results:In the first part,an optimized scanning method was designed,and a definitive restoration of a patient was successfully completed.In the second part,the peri-implant soft-tissue without the ISPR immediately collapsed,particularly on the palatine side of the labial mucosa and labial side of the palatine mucosa.Consequently,the routine scanning method led to 414.7±116.0μm of overall dimensional deformation in the cuff-like subgingival region,which was significantly larger(p<0.0001)than that in the optimized method(230.6±85.5μm)in the same aesthetic area.In the third part,it demonstrated a precision level of 199.9 ± 39.3μm for customed impression and 197.2±50.5μm for the optimized scanning method,which differ from deviation values 397.4±93.6μm of the routine scanning method.A statistically significant difference was found among three groups(p<0.05).The order of chair-side time from short to long was the routine scanning,optimized scanning,conventional impression and customed impression.In terms of patient comfort survey,most patients had higher acceptance of intraoral scanning.Conclusions:Our data showed that the optimized scanning led to a significant peri-implant gingival tissue deviation,indicating that the ISPR is necessary to maintain the gingival contour and emergence profile in the maxillary esthetic area.Therefore,it is necessary to have the appropriate gingival support to improve the accuracy of intraoral scanning for peri-implant soft-tissue in the maxillary esthetic area. |
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