Table 2.
Table Characteristics of included studies.
| Study ID and design | Participants / Implants with Location,Intervention | IOS system and digital analysis software | Outcomes assessed and Comparator | Major findings | Limitations |
| Xiong et al. [9] prospective clinical study | 16 / 16 anterior maxillaIntervention: IOS of peri-implant soft tissue with and without implant-supported provisional restoration (ISPR) | TRIOS (3Shape, Copenhagen, Denmark)Software: Geomagic Control X (3D Systems, Rock Hill, USA) | Peri-implant soft tissue deviation (µm) in 2D and 3D; accuracy of mucosal profile replicationComparator: conventional impression using ISPR as impression coping | Removal of ISPR led to rapid peri-implant mucosal collapse. IOS with ISPR in place showed significantly higher accuracy than IOS without ISPR (mean 3D deviation: 230.6 ± 85.5 μm vs 414.7 ± 116.0 μm; p < .0001) | Small sample size; limited to single implants on only anterior maxilla; short-term assessment; conventional impression may introduce material-related inaccuracies |
| da Silva Marques et al. [10] cross-over pilot clinical study | 6 / 6 anterior maxillaIntervention: digital intraoral impression obtained immediately after removal of provisional crown and compared with conventional impression using customized implant impression coping (CIIC) | TRIOS (3Shape, Copenhagen, Denmark)Software: Geomagic Design X (3D Systems, Rock Hill, USA) | 3D trueness (RMS, μm) of hard and soft tissues, peri-implant emergence profile, effect size (Hedges’ g)Comparator: conventional polyvinyl siloxane impression with customized implant impression coping and extraoral scanning | Digital impressions showed statistically significant differences in peri-implant soft tissue replication compared with CIIC (overall RMS ≈ 244 μm; large effect size), but discrepancies were below the clinically detectable threshold (1 mm) | Small sample size; pilot design; limited to single implants on only anterior maxilla; no correlation analysis for implant depth, connection type, or gingival biotype; clinical impact on esthetic outcomes not assessed |
| Duran et al. [11] pilot clinical study | 10 / 10 anterior maxillaIntervention: digital intraoral impression of peri-implant soft tissue immediately after removal of implant-supported fixed interim restoration (ISFIR); STL superimposition and linear cross-sectional measurements | CEREC Omnicam (Sirona Dental Systems, Bensheim, Germany)Software: Cerec SW 4.4 (SironaDental System, Bensheim, Germany) | Linear dimensional changes (mm) of peri-implant soft tissue profile in buccolingual and mesiodistal directions at coronal and mid-gingival levelsComparator: conventional polyvinyl siloxane impression using ISFIR as customized impression transfer, followed by stone cast fabrication and digital scanning | Significant dimensional discrepancies were observed between the ISFIR emergence profile and unsupported peri-implant soft tissue captured by IOS, with deviations up to 1.35 mm buccolingually and 1.29 mm mesiodistally; digital impressions did not accurately reproduce soft tissue contours after ISFIR removal | Small sample size; pilot design; only single implants in the anterior maxilla; absence of repeated measurements; only linear (2D) measurements performed; short observation period |
| Ling et al. [12] prospective clinical pilot study | 14 / 20 anterior maxillaIntervention: comparison of direct versus indirect IOS techniques for duplicating peri-implant soft tissue contour during definitive crown delivery; STL superimposition before and after delivery | TRIOS 3 (3Shape, Copenhagen, Denmark)Software: DentalDB (Exocad GmbH, Darmstadt, Germany) | Linear deviations of peri-implant mucosa (labial and palatal gingival margin height, thickness); volumetric deviations of labial and palatal soft tissue; PESComparator: direct digital impression technique based on peri-implant soft tissue profile immediately after provisional crown removal | Indirect technique resulted in significantly smaller labial and palatal tissue thickness deviations and lower labial soft-tissue volume changes compared with the direct technique; palatal tissue collapse occurred mainly with the direct technique; no significant differences in PES between techniques | Pilot design; limited sample size; no conventional impression control; short-term evaluation only; limited to single implants on only anterior maxilla; long-term esthetic stability not assessed |
| Docampo-Vázquez et al. [13] pilot clinical trial | 10 / 10 mandibleIntervention: free gingival graft performed to increase peri-implant keratinized tissue; serial digital IOS obtained preoperatively and at 1 week, 1, 3, and 6 months to assess healing | True Definition (3M ESPE, Saint Paul, USA)Software: 3D Geomagic Capture Wrap (3D Systems, Rock Hill, USA) | Volumetric changes (mm³) of peri-implant soft tissues at donor and recipient sites; linear width of keratinized tissue; repeatability and reproducibility (Gage R&R)Comparator: conventional clinical linear measurements (endodontic file with rubber stop) | Digital technique demonstrated high repeatability and reproducibility (<10% variability); recipient sites showed significantly higher soft-tissue volume than donor sites at all follow-ups; no significant differences between digital and conventional methods for linear width, but conventional measurements lacked repeatability | Pilot study with small sample size; limited to implants in overdenture patients; no comparison with other soft-tissue augmentation techniques or materials; volumetric assessment limited to implant sites only |
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