Complete-arch fixed reconstruction by means of guided surgery and immediate loading: a retrospective clinical study on 12 patients with 1 year of follow-up.

BACKGROUND: Guided implant surgery is considered as a safe and minimally invasive flapless procedure. However, flapless guided surgery, implant placement in post-extraction sockets and immediate loading of complete-arch fixed reconstructions without artificial gum are still not throughly evaluated. The aim of the present retrospective clinical study was to document the survival and success of complete-arch fixed reconstructions without artificial gum, obtained by means of guided surgery and immediate loading of implants placed also in fresh extraction sockets. METHODS: A total of 12 patients (5 males and 7 females, with a mean age of 50.0 ± 13.8) were enrolled in this study. Implant planning was performed with a guided surgery system (RealGuide®, 3Diemme, Como, Italy), from which 3D-printed surgical templates were fabricated. All implants (Esthetic Line-EL®, C-Tech, Bologna, Italy) were placed through the guides and immediately loaded by means of a temporary fixed full-arch restoration without any artificial gum; the outcome measures were implant stability at placement, implant survival, complications, prosthetic success, soft-tissue stability, and patient satisfaction. RESULTS: One hundred ten implants (65 of them post-extractive) were placed flapless through a guided surgery procedure and then immediately loaded by means of provisional fixed full arches. Successful implant stability at placement was achieved in all cases. After a provisionalization period of 6 months, 72 fixed prosthetic restorations were delivered. Only 2 implants failed to osseointegrate and had to be removed, in one patient, giving a 1-year implant survival rate of 98.2% (108/110 surviving implants); 8/12 prostheses did not undergo any failure or complication during the entire follow-up period. At the 1-year follow-up control, soft-tissue was stable in all patients and showed satesfactory aesthetic results. CONCLUSIONS: Within the limits of this study, complete-arch fixed reconstruction by means of guided surgery and immediate loading of implants placed in fresh extraction sockets appears to be a reliable and successful procedure. Further long-term prospective studies on a larger sample of patients are needed to confirm these positive outcomes.

Trueness and precision of 5 intraoral scanners in the impressions of single and multiple implants: a comparative in vitro study.

BACKGROUND: Until now, a few studies have addressed the accuracy of intraoral scanners (IOSs) in implantology. Hence, the aim of this in vitro study was to assess the accuracy of 5 different IOSs in the impressions of single and multiple implants, and to compare them. METHODS: Plaster models were prepared, representative of a partially edentulous maxilla (PEM) to be restored with a single crown (SC) and a partial prosthesis (PP), and a totally edentulous maxilla (TEM) to be restored with a full-arch (FA). These models were scanned with a desktop scanner, to capture reference models (RMs), and with 5 IOSs (CS 3600®, Trios3®, Omnicam®, DWIO®, Emerald®); 10 scans were taken for each model, using each IOS. All IOS datasets were loaded into a reverse-engineering software where they were superimposed on the corresponding RMs, to evaluate trueness, and superimposed on each other within groups, to determine precision. A statistical analysis was performed. RESULTS: In the SC, CS 3600® had the best trueness (15.2 ± 0.8 µm), followed by Trios3® (22.3 ± 0.5 µm), DWIO® (27.8 ± 3.2 µm), Omnicam® (28.4 ± 4.5 µm), Emerald® (43.1 ± 11.5 µm). In the PP, CS 3600® had the best trueness (23 ± 1.1 µm), followed by Trios3® (28.5 ± 0.5 µm), Omnicam® (38.1 ± 8.8 µm), Emerald® (49.3 ± 5.5 µm), DWIO® (49.8 ± 5 µm). In the FA, CS 3600® had the best trueness (44.9 ± 8.9 µm), followed by Trios3® (46.3 ± 4.9 µm), Emerald® (66.3 ± 5.6 µm), Omnicam® (70.4 ± 11.9 µm), DWIO® (92.1 ± 24.1 µm). Significant differences were found between the IOSs; a significant difference in trueness was found between the contexts (SC vs. PP vs. FA). In the SC, CS 3600® had the best precision (11.3 ± 1.1 µm), followed by Trios3® (15.2 ± 0.8 µm), DWIO® (27.1 ± 10.7 µm), Omnicam® (30.6 ± 3.3 µm), Emerald® (32.8 ± 10.7 µm). In the PP, CS 3600® had the best precision (17 ± 2.3 µm), followed by Trios3® (21 ± 1.9 µm), Emerald® (29.9 ± 8.9 µm), DWIO® (34.8 ± 10.8 µm), Omnicam® (43.2 ± 9.4 µm). In the FA, Trios3® had the best precision (35.6 ± 3.4 µm), followed by CS 3600® (35.7 ± 4.3 µm), Emerald® (61.5 ± 18.1 µm), Omnicam® (89.3 ± 14 µm), DWIO® (111 ± 24.8 µm). Significant differences were found between the IOSs; a significant difference in precision was found between the contexts (SC vs. PP vs. FA). CONCLUSIONS: The IOSs showed significant differences between them, both in trueness and in precision. The mathematical error increased in the transition from SC to PP up to FA, both in trueness than in precision.

Computer-assisted, template-guided immediate implant placement and loading in the mandible: a case report.

BACKGROUND: Computer-assisted implant planning has become an important diagnostic and therapeutic tool in modern dentistry. This case report emphasizes the possibilities in modern implantology combining virtual implant planning, guided surgery with tooth and implant supported templates, immediate implant placement and loading. CASE PRESENTATION: A straight forward approach was followed for the mandible presenting with hopeless lower incisors. Diagnosis, decision making and treatment approach were based on clinical findings and detailed virtual three-dimensional implant planning. Extractions of the hopeless mandibular incisors, immediate and guided implant placement of six standard implants, and immediate loading with a provisional fixed dental prosthesis (FDP) were performed fulfilling patient's functional and esthetic demands. The final computer assisted design / computer assisted manufacturing (CAD/CAM) FDP with a titanium framework and composite veneering was delivered after 6 months. At the 1-year recall the FDP was free of technical complications. Stable bony conditions and a healthy peri-implant mucosa could be observed. CONCLUSIONS: Computer assisted implantology including three-dimensional virtual implant planning, guided surgery, and CAD/CAM fabrication of provisional and final reconstructions allowed for a concise treatment workflow with predictable esthetic and functional outcomes in this mandibular full-arch case. The combination of immediate implant placement and immediate loading was considerably more complex and required a high level of organization between implantologist, technician and patient. After the usage of a first tooth-supported surgical template with subsequent extraction of the supporting teeth, a second surgical template stabilized on the previously inserted implants helped to transfer the planned implant position in the extraction sites with a guided approach.

Full in-Office Guided Surgery with Open Selective Tooth-Supported Templates: A Prospective Clinical Study on 20 Patients.

BACKGROUND: Guided implant surgery appears to have several benefits, such as the possibility of inserting flapless implants in a prosthetically driven manner, avoiding dangerous anatomical structures. However, to date, only a few surgeons routinely use guided surgery in partially edentulous patients. AIM: To present the results obtained with tooth-supported surgical templates characterized by an innovative open design with selective support, and manufactured via a full in-office procedure with a low-cost desktop 3D printer. METHODS: Over a two-year period (2016⁻2018), all partially edentulous patients with one to three missing teeth (in maxilla and/or mandible), referred to a private dental practice for restoration with dental implants, were considered for inclusion in this prospective clinical study. An intraoral scanner (CS 3600®, Carestream Dental) and cone beam computed tomography (CS 9300®, Carestream Dental) were used to acquire the 3D information on the patients. Guided surgery software (SMOP®, Swissmeda) was used to plan the surgeries and to design open, selective, tooth-supported templates that were fabricated with a stereolithographic (SLA) desktop 3D printer (XFAB2000®, DWS). Guided implant surgeries were performed and patients were followed for a period of one year. The study outcomes were fit and stability of surgical templates, duration (time) of surgery, intra and post-operative complications, and implant stability and survival. RESULTS: Twenty (20) partially edentulous patients (9 males, 11 females; mean age 54.4 ± 9.4 years) were included in the study; 28 open, selective, tooth-supported templates were designed with the aim of inserting 38 implants. Among the surgical templates, 24 had optimal fit and stability, three had optimal fit and sufficient stability, and only one had inadequate fit and unsatisfactory stability and was therefore not suitable for clinical use. The average time of the intervention was 15.7 ± 5.2 min per template. No intra-operative complications were reported, but one implant was not stable at placement and had to be removed. In total, 36 implants were restored with 10 two-unit fixed partial prostheses and 16 single crowns. All implants were successfully functioning at one year, even if, in two single crowns, minor prosthetic complications (abutment screw loosening) occurred. CONCLUSIONS: Full in-office guided surgery with open, selective, tooth-supported templates seem to represent a clinically predictable surgical procedure to restore partially edentulous patients. Further studies are needed to confirm these positive outcomes.

Clinical applications and effectiveness of guided implant surgery: a critical review based on randomized controlled trials.

BACKGROUND: Nowadays implant placement protocols are widespread among clinicians all over the world. However, available literature, only partially analyses what can be potential benefits for the clinicians and patients, often focusing just on specific aspects, such as accuracy. The purpose of this review is to compare computer guided implant placement with conventional treatment protocols. METHODS: A search strategy according to the P-I-C-O format was developed and executed using an electronic MEDLINE plus manual search from 2000 up to December 2016. This review included only randomized controlled trials (RCTs) focusing on subjects treated with digital workflow for oral implant placement compared to conventional procedures. Data were extracted from eligible papers and analysed. All kinds of outcomes were considered, even patient-related and economical outcomes. RESULTS: The search strategy revealed 16 articles; additional manual searches selected further 21 publications. Afterwards the evaluation of articles, only two studies could be selected for subsequent data extraction. The two identified RCTs analysed primary outcomes as prosthesis failure, implant failure, biological or prosthetic complications, and secondary outcomes as periimplant marginal bone loss. One RCT evaluated also the duration of treatment, post-surgical progress, additional treatment costs and patient satisfaction. The other RCT focused instead on evaluating eventual improvement of patient's quality of life. In both selected studies, were not observed by the authors statistically significant differences between clinical cases treated with digital protocols and those treated with conventional ones. In one RCT, however post-surgical progress evaluation showed more patients' self-reported pain and swelling in conventional group. CONCLUSIONS: Within the limitation of this review, based on only two RCTs, the only evidence was that implant survival rate and effectiveness are similar for conventional and digital implant placement procedures. This is also confirmed by many other studies with however minor scientific evidence levels. Reduction of post-operative pain, surgical time and overall costs are discussed. Authors believe that scientific research should focus more in identifying which clinical situations can get greatest benefits from implant guided surgery. This should be done with research protocols such as RCT that assess comprehensively the advantages and disadvantages of fully digital surgical protocols.

Accuracy of four intraoral scanners in oral implantology: a comparative in vitro study.

BACKGROUND: Until now, only a few studies have compared the ability of different intraoral scanners (IOS) to capture high-quality impressions in patients with dental implants. Hence, the aim of this study was to compare the trueness and precision of four IOS in a partially edentulous model (PEM) with three implants and in a fully edentulous model (FEM) with six implants. METHODS: Two gypsum models were prepared with respectively three and six implant analogues, and polyether-ether-ketone cylinders screwed on. These models were scanned with a reference scanner (ScanRider®), and with four IOS (CS3600®, Trios3®, Omnicam®, TrueDefinition®); five scans were taken for each model, using each IOS. All IOS datasets were loaded into reverse-engineering software, where they were superimposed on the reference model, to evaluate trueness, and superimposed on each other within groups, to determine precision. A detailed statistical analysis was carried out. RESULTS: In the PEM, CS3600® had the best trueness (45.8 ± 1.6µm), followed by Trios3® (50.2 ± 2.5µm), Omnicam® (58.8 ± 1.6µm) and TrueDefinition® (61.4 ± 3.0µm). Significant differences were found between CS3600® and Trios3®, CS3600® and Omnicam®, CS3600® and TrueDefinition®, Trios3® and Omnicam®, Trios3® and TrueDefinition®. In the FEM, CS3600® had the best trueness (60.6 ± 11.7µm), followed by Omnicam® (66.4 ± 3.9µm), Trios3® (67.2 ± 6.9µm) and TrueDefinition® (106.4 ± 23.1µm). Significant differences were found between CS3600® and TrueDefinition®, Trios3® and TrueDefinition®, Omnicam® and TrueDefinition®. For all scanners, the trueness values obtained in the PEM were significantly better than those obtained in the FEM. In the PEM, TrueDefinition® had the best precision (19.5 ± 3.1µm), followed by Trios3® (24.5 ± 3.7µm), CS3600® (24.8 ± 4.6µm) and Omnicam® (26.3 ± 1.5µm); no statistically significant differences were found among different IOS. In the FEM, Trios3® had the best precision (31.5 ± 9.8µm), followed by Omnicam® (57.2 ± 9.1µm), CS3600® (65.5 ± 16.7µm) and TrueDefinition® (75.3 ± 43.8µm); no statistically significant differences were found among different IOS. For CS3600®, For CS3600®, Omnicam® and TrueDefinition®, the values obtained in the PEM were significantly better than those obtained in the FEM; no significant differences were found for Trios3®. CONCLUSIONS: Significant differences in trueness were found among different IOS; for each scanner, the trueness was higher in the PEM than in the FEM. Conversely, the IOS did not significantly differ in precision; for CS3600®, Omnicam® and TrueDefinition®, the precision was higher in the PEM than in the FEM. These findings may have important clinical implications.

Trueness and Precision of Four Intraoral Scanners in Oral Implantology: A Comparative in Vitro Study.

PURPOSE: The aim of this study was to compare the trueness and precision of four intraoral scanners used in oral implantology. METHODS: Two stone models were prepared, representing a partially and a totally edentulous maxilla, with three and six implant analogues, respectively, and polyether-ether-ketone (PEEK) cylinders screwed on. The models were digitized with an industrial scanner (IScan D104I®) used as a reference, and with four intraoral scanners (Trios®; CS 3500®; Zfx Intrascan®; Planscan®). Five scans were taken for each model, using each different intraoral scanner. All datasets were loaded into reverse-engineering software (Geomagics 2012®), where intraoral scans were superimposed on the reference model, to evaluate general trueness, and superimposed on each other within groups, to evaluate general precision. General trueness and precision of any scanner were compared by model type, through an ANOVA model including scanner, model and their interaction. Finally, the distance and angles between simulated implants were measured in each group, and compared to those of the reference model, to evaluate local trueness. RESULTS: In the partially edentulous maxilla, CS 3500® had the best general trueness (47.8 µm) and precision (40.8 µm), followed by Trios® (trueness 71.2 µm, precision 51.0 µm), Zfx Intrascan® (trueness 117.0 µm, precision 126.2 µm), and Planscan® (trueness 233.4 µm, precision 219.8 µm). With regard to general trueness, Trios® was significantly better than Planscan®, CS 3500® was significantly better than Zfx Intrascan® and Planscan®, and Zfx Intrascan® was significantly better than Planscan®; with regard to general precision, Trios® was significantly better than Zfx Intrascan® and Planscan®, CS 3500® was significantly better than Zfx Intrascan® and Planscan®, and Zfx Intrascan® was significantly better than Planscan®. In the totally edentulous maxilla, CS 3500® had the best performance in terms of general trueness (63.2 µm) and precision (55.2 µm), followed by Trios® (trueness 71.6 µm, precision 67.0 µm), Zfx Intrascan® (trueness 103.0 µm, precision 112.4 µm), and Planscan® (trueness 253.4 µm, precision 204.2 µm). With regard to general trueness, Trios® was significantly better than Planscan®, CS 3500® was significantly better than Zfx Intrascan® and Planscan®, and Zfx Intrascan® was significantly better than Planscan®; with regard to general precision, Trios® was significantly better than Zfx Intrascan® and Planscan®, CS 3500® was significantly better than Zfx Intrascan® and Planscan®, and Zfx Intrascan® was significantly better than Planscan®. Local trueness values confirmed these results. CONCLUSIONS: Although no differences in trueness and precision were found between partially and totally edentulous models, statistically significant differences were found between the different scanners. Further studies are required to confirm these results.