Solid index and reverse implant library for the fabrication of a bar for overdenture: a proof of concept.

OBJECTIVES: To present a solid index (SI), a 3D-printed replica of a patient's preexisting complete denture, which allows the dentist to accurately capture the position of the implants and the dental technician to model a bar for overdenture (OD) in CAD software with the use of reverse implant libraries. MATERIALS AND METHODS: A patient in need of rehabilitation of a fully edentulous mandible was restored with an implant OD supported by a polyetheretherketone (PEEK) milled bar. The position of the implants was captured through a physical impression using an SI, with the transfers screwed in. The analogs were then connected, and the SI was scanned upside down to directly capture the position of the implants in the space. This scan was used to design the bar in CAD software using reverse implant libraries, without the need for pouring any SI-derived cast or for using any scanbody. The bar was milled in PEEK. RESULTS: When delivered to the patient, the bar was clinically precise, screwing perfectly onto the implants without any tension or misfit. CONCLUSIONS: The present proof-of-concept article supports the use of an SI and reverse implant libraries for the fabrication of a bar for OD. Further clinical studies are needed to confirm these results.

Trueness of 12 intraoral scanners in the full-arch implant impression: a comparative in vitro study.

BACKGROUND: The literature has not yet validated the use of intraoral scanners (IOSs) for full-arch (FA) implant impression. Hence, the aim of this in vitro study was to assess and compare the trueness of 12 different IOSs in FA implant impression. METHODS: A stone-cast model of a totally edentulous maxilla with 6 implant analogues and scanbodies (SBs) was scanned with a desktop scanner (Freedom UHD®) to capture a reference model (RM), and with 12 IOSs (ITERO ELEMENTS 5D®; PRIMESCAN® and OMNICAM®; CS 3700® and CS 3600®; TRIOS3®; i-500®; EMERALD S® and EMERALD®; VIRTUO VIVO® and DWIO®; RUNEYES QUICKSCAN®). Ten scans were taken using each IOS, and each was compared to the RM, to evaluate trueness. A mesh/mesh method and a nurbs/nurbs method were used to evaluate the overall trueness of the scans; linear and cross distances between the SBs were used to evaluate the local trueness of the scans. The analysis was performed using reverse engineering software (Studio®, Geomagics; Magics®, Materialise). A statistical evaluation was performed. RESULTS: With the mesh/mesh method, the best results were obtained by CS 3700® (mean error 30.4 µm) followed by ITERO ELEMENTS 5D® (31.4 µm), i-500® (32.2 µm), TRIOS 3® (36.4 µm), CS 3600® (36.5 µm), PRIMESCAN® (38.4 µm), VIRTUO VIVO® (43.8 µm), RUNEYES® (44.4 µm), EMERALD S® (52.9 µm), EMERALD® (76.1 µm), OMNICAM® (79.6 µm) and DWIO® (98.4 µm). With the nurbs/nurbs method, the best results were obtained by ITERO ELEMENTS 5D® (mean error 16.1 µm), followed by PRIMESCAN® (19.3 µm), TRIOS 3® (20.2 µm), i-500® (20.8 µm), CS 3700® (21.9 µm), CS 3600® (24.4 µm), VIRTUO VIVO® (32.0 µm), RUNEYES® (33.9 µm), EMERALD S® (36.8 µm), OMNICAM® (47.0 µm), EMERALD® (51.9 µm) and DWIO® (69.9 µm). Statistically significant differences were found between the IOSs. Linear and cross distances between the SBs (local trueness analysis) confirmed the data that emerged from the overall trueness evaluation. CONCLUSIONS: Different levels of trueness were found among the IOSs evaluated in this study. Further studies are needed to confirm these results.

Comparative Study between Laser Light Stereo-Lithography 3D-Printed and Traditionally Sintered Biphasic Calcium Phosphate Scaffolds by an Integrated Morphological, Morphometric and Mechanical Analysis.

In dental districts, successful bone regeneration using biphasic calcium phosphate materials was recently explored. The present study aimed to perform a comparative study between 3D-printed scaffolds produced by laser light stereo-lithography (SLA) and traditionally sintered biphasic calcium phosphate scaffolds by an integrated morphological, morphometric and mechanical analysis. METHODS: Biphasic calcium phosphate (30% HA/70% ß-TCP) samples, produced by SLA-3D-printing or by traditional sintering methods, were tested. The experimental sequence included: (1) Microtomography (microCT) analyses, to serve as control-references for the 3D morphometric analysis; (2) loading tests in continuous mode, with compression up to fracture, to reconstruct their mechanical characteristics; and (3) microCT of the same samples after the loading tests, for the prediction of the morphometric changes induced by compressive loading of the selected materials. All the biomaterials were also studied by complementary scanning electron microscopy to evaluate fracture regions and surfaces. RESULTS: The characterization of the 3D mineralized microarchitecture showed that the SLA-3D-printed biomaterials offer performances comparable to and in some cases better than the traditionally sintered ones, with higher mean thickness of struts and pores. Interestingly, the SLA-3D-printed samples had a higher ultimate strength than the sintered ones, with a smaller plastic region. Moreover, by SEM observation, it was observed that fractures in the SLA-3D-printed samples were localized in the structure nodes or on the external shells of the rods, while all the traditionally sintered samples revealed a ductile fracture surface. CONCLUSIONS: The reduction of the region of plastic deformation in the SLA-3D-printed samples with respect to traditionally sintered biomaterials is expected to positively influence, in vivo, the cell adhesion. Both microCT and SEM imaging revealed that the studied biomaterials exhibit a structure more similar to human jaw than the sintered biomaterials.

A novel guided surgery system with a sleeveless open frame structure: a retrospective clinical study on 38 partially edentulous patients with 1 year of follow-up.

BACKGROUND: This retrospective clinical study aims to present results of experience with a novel guided surgery system with a sleeveless, open-frame structure, in which the surgical handpiece (not the drills used for preparation) is guided. METHODS: This study was based on an evaluation of the records of partially edentulous patients who had been treated with a sleeveless open-frame guided surgery system (TWIN-Guide®, 2Ingis, Brussels, Belgium), between January 2015 and December 2017. Inclusion criteria were patients with good systemic/oral health and a minimum follow-up of 1 year. Exclusion criteria were patients who had been treated without a guide, or with a guide with sleeves, patients with systemic/oral diseases and who did not have a follow-up of 1 year. The main outcomes were surgical (fit and stability of the surgical guide, duration of the intervention, implant stability, and any intra-operative or immediate post-operative complication), biologic, and prosthetic. RESULTS: Thirty-eight patients (24 males, 14 females; mean age 56.5 ± 14.0 years) were included in the study. These patients had been treated with 110 implants inserted by means of 40 sleeveless, open-frame guides. With regard to fit and stability, 34 guides were excellent, 4 acceptable, and 2 inadequate for use. The mean duration of the intervention was 23.7 (± 6.7) minutes. Immediately after placement, 2 fixtures were not stable and had to be removed. Two patients experienced pain/swelling after surgery. The 108 surviving implants were restored with 36 single crowns and 32 fixed partial prostheses (24 two-unit and 8 three-unit bridges); these restorations survived until the 1-year follow-up, with a low incidence of biologic and prosthetic complications. CONCLUSIONS: Within the limits of this study, this novel guided surgery system with sleeveless, open frame-structure guides seems to be clinically reliable; further studies on a larger sample of patients are needed to confirm these 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.

Augmented reality for dental implantology: a pilot clinical report of two cases.

BACKGROUND: Despite the limited number of articles dedicated to its use, augmented reality (AR) is an emerging technology that has shown to have increasing applications in multiple different medical sectors. These include, but are not limited to, the Maxillo-facial and Dentistry disciplines of medicine. In these medical specialties, the focus of AR technology is to achieve a more visible surgical field during an operation. Currently, this goal is brought about by an accurate display of either static or dynamic diagnostic images via the use of a visor or specific glasses. The objective of this study is to evaluate the feasibility of using a virtual display for dynamic navigation via AR. The secondary outcome is to evaluate if the use of this technology could affect the accuracy of dynamic navigation. CASE PRESENTATION: Two patients, both needing implant rehabilitation in the upper premolar area, were treated with flapless surgery. Prior to the procedure itself, the position of the implant was virtually planned and placed for each of the patients using their previous scans. This placement preparation contributed to a dynamic navigation system that was displayed on AR glasses. This, in turn, allowed for the use of a computer-aided/image-guided procedure to occur. Dedicated software for surface superimposition was then used to match the planned position of the implant and the real one obtained from the postoperative scan. Accuracies, using this procedure were evaluated by way of measuring the deviation between real and planned positions of the implants. For both surgeries it was possible to proceed using the AR technology as planned. The deviations for the first implant were 0.53 mm at the entry point and 0.50 mm at the apical point and for the second implant were 0.46 mm at the entry point and 0.48 mm at the apical point. The angular deviations were respectively 3.05° and 2.19°. CONCLUSIONS: From the results of this pilot study, it seems that AR can be useful in dental implantology for displaying dynamic navigation systems. While this technology did not seem to noticeably affect the accuracy of the procedure, specific software applications should further optimize the results.

Combining Intraoral Scans, Cone Beam Computed Tomography and Face Scans: The Virtual Patient.

PURPOSE: The aim of this literature review was to provide an update on the current scientific knowledge in the field of 3D virtual patient science and to identify a possible easy, smart, and affordable method to combine different file formats obtained from different digital devices. METHODS: Electronic searches of the Medline database was performed, up to May 2017, for articles dealing with the construction of a 3D virtual patient; the matching of data acquired with different digital devices (cone beam computed tomography, CBCT; face scanner, FS; intraoral scanner, IOS; and desktop scanner, DS) was considered. The inclusion of studies was based on the superimposition of at least 2 different digital sources. RESULTS: Twenty-five studies were selected for subsequent examination. Only 3 studies analyzed the feasibility of superimposition of 3 different types of 3D data (CBCT + FS + IOS/DS). The most frequently used matching procedure was between CBCT and FS and CBCT and IOS/DS. CONCLUSION: The procedure of superimposition of data from CBCT, IOS, and FS is currently feasible and it is now possible to create a 3D "virtual patient" to better diagnose, plan the treatment, and communicate with patients.

Prosthetic Complications Affecting Single-Tooth Morse-Taper Connection Implants.

PURPOSE: To evaluate the long-term cumulative implant survival rate (CISR%) and cumulative implant-crown success rate (CICSR%) of single-tooth Morse-taper connection implants, with particular attention to documenting the incidence of prosthetic complications. METHODS: The customized records of all patients who had been treated with single-tooth Morse-taper connection implants in 2 dental centers during the period between January 2002 and December 2012 were revisited. These records included patient-related (gender, age at surgery, smoking, bruxism), implant-related (date of insertion, site/location, and length/diameter of the implant, previous/concomitant bone regeneration), and restoration-related (date of delivery of the provisional and final crown) information. In addition, these records contained information about any implant failure and biologic and/or prosthetic complication that occurred during the follow-up period as well as the radiographic documentation. The follow-up period comprised between 5 and 15 years. The main outcomes were CISR% and CICSR%, with the latter being defined as the condition in which no complication had affected the surviving implant-supported crown during the entire follow-up. Life-table analysis was used for the analysis of CISR% and CICSR%. Peri-implant marginal bone resorption (PIMBR) at 5, 10, and 15 years was a secondary outcome of this study. RESULTS: In total, 578 patients who had received 612 implants were included in this study. The overall CISR% at 15 years was 94.8% (94.2% maxilla, 95.3% mandible). Among the surviving crowns, the overall CICSR% at 15 years was 94.5% (93.1% and 94.9% for anterior and posterior crowns, respectively), and the incidence of prosthetic complications was low (1.5%). The PIMBL amounted to 0.38 ±â€Š0.29 mm, 0.49 ±â€Š0.35 mm, and 0.94 ±â€Š0.58 mm at the 5-, 10-, and 15-year follow-ups, respectively. CONCLUSION: Morse-taper connection implants represent a reliable treatment procedure for the restoration of single-tooth gaps in the long term, with high CISR% (94.8%) at 15 years, a very low incidence of complications, and a high CICSR% (94.5%).

Osteo-regeneration personalized for children by rapid maxillary expansion: an imaging study based on synchrotron radiation microtomography.

BACKGROUND: Personalized maxillary expansion procedure has been proposed to correct maxillary transversal deficiency; different protocols of stem cell activation have been suggested and rapid maxillary expansion (RME) is the most commonly used among clinicians. The present study aimed to quantify in three-dimensions (3D) the osteo-regeneration of the midpalatal suture in children submitted to RME. METHODS: Three patients (mean age 8.3 ± 0.9 years) were enrolled in the study to preform biopsy of midpalatal suture. Two patients (subjects 1 and 2) were subjected to RME before biopsy. The third patient did not need maxillary expansion treatment and was enrolled as control (subject 3). Midpalatal suture samples were harvested 7 days after RME in subject 1, and 30 days after RME in subject 2. The samples were harvested with the clinical aim to remove bone for the supernumerary tooth extraction. When possible, maxillary suture and bone margins were both included in the sample. All the biopsies were evaluated by complementary imaging techniques, namely Synchrotron Radiation-based X-ray microtomography (microCT) and comparative light and electron microscopy. RESULTS: In agreement with microscopy, it was detected by microCT a relevant amount of newly formed bone both 7 days and 30 days after RME, with bone growth and a progressive mineralization, even if still immature respect to the control, also 30 days after RME. Interestingly, the microCT showed that the new bone was strongly connected and cross-linked, without a preferential orientation perpendicular to the suture's long axis (previously hypothesized by histology), but with well-organized and rather isotropic 3D trabeculae. CONCLUSIONS: The microCT imaging revealed, for the first time to the authors' knowledge, the 3D bone regeneration in children submitted to RME.

Aesthetic outcome of immediately restored single implants placed in extraction sockets and healed sites of the anterior maxilla: a retrospective study on 103 patients with 3 years of follow-up.

OBJECTIVES: The aim of this study was to compare the aesthetic outcome of single implants in extraction sockets and healed ridges of the anterior maxilla by means of the pink aesthetic score/white aesthetic score (PES/WES) index. MATERIALS AND METHODS: This retrospective study was based on data from 103 patients (43 males, 60 females) aged 24-65 years (mean age 41.4 ± 13.8 years) who had been successfully treated with a single implant in the anterior maxilla, in four different clinical centres. Forty-two patients (mean age 46.5 ± 15.1 years) were treated with a single implant in a fresh post-extraction socket (immediate implant treatment, IIT), while 61 patients (mean age 38.0 ± 11.8 years) were treated with a single implant in a healed site (conventional implant treatment, CIT). Two independent calibrated examiners applied the PES/WES index to the 103 single-tooth restorations, respectively 3 months and 3 years after implant placement. RESULTS: A few biological (4.8%) and prosthetic (8.7%) complications were reported. Both IIT and CIT yielded satisfactory aesthetic outcomes. At the delivery of the final restoration, a PES/WES score of 16.6 ± 2.6 and 15.7 ± 3.0 was reported for IIT and CIT, respectively: this difference was not statistically significant. A higher decrease in the PES/WES score was observed with CIT over time. At 3 years, a PES/WES score of 16.4 ± 2.8 and 15.2 ± 3.3 was reported for IIT and CIT, respectively: this difference was statistically significant. IIT seemed to yield better aesthetic outcomes in young patients (≤30 years), with implants placed in central incisor/cuspid areas, in the presence of bone contouring. CONCLUSIONS: Both immediate and conventional single-implant treatment in the anterior maxilla can yield satisfactory aesthetic outcomes, when performed by experienced clinicians in well-selected cases. Further studies are needed to confirm these results.

Early bone formation around immediately loaded implants with nanostructured calcium-incorporated and machined surface: a randomized, controlled histologic and histomorphometric study in the human posterior maxilla.

OBJECTIVE: The aim of this randomized, controlled histologic/histomorphometric study was to compare the early bone formation around immediately loaded implants with nanostructured calcium-incorporated (NCI) and machined (MA) surface, placed in the human posterior maxilla. MATERIALS AND METHODS: Fifteen fully edentulous patients (six males; nine females; mean age 57.9 ± 6.7 years) were selected for this study. Each patient was installed with two temporary transmucosal implants, with different surfaces: one NCI (test) and one MA (control) implant. All temporary implants were placed in the posterior maxilla, according to a split-mouth design, to help to support an interim complete maxillary denture. After 8 weeks, all temporary transmucosal implants were retrieved for histologic/histomorphometric evaluation. The bone-to-implant contact (BIC%) and the bone density (BD%) were calculated. The Wilcoxon matched-pairs signed-rank test was used to evaluate differences (BIC%, BD%) between the surfaces. The level of significance was set at 0.05. RESULTS: Eight weeks after placement, 24 clinically stable implants (12 test, 12 control) were subjected to histologic/histomorphometric evaluation. In the MA implants, the histomorphometric evaluation revealed a mean BIC(±SD)% and BD(±SD)% of 21.2(±4.9)% and 29.8(±7.8)%, respectively. In the NCI implants, the histomorphometric analysis revealed a mean BIC(±SD)% and BD(±SD)% of 39.7(±8.7)% and 34.6(±7.2)%, respectively. A statistically significant difference was found between the two surfaces with regard to BIC% (p < 0.001), while no significant difference was found with regard to BD% (p = 0.09). CONCLUSIONS: The NCI surface seems to increase the peri-implant endosseous healing properties in the native bone of the posterior maxilla, under immediate loading conditions, when compared with the MA surface. CLINICAL RELEVANCE: Under immediate loading conditions in the human posterior maxilla, the nanostructured calcium-incorporated surface has led to better histologic and histomorphometric results than the machined surface; therefore, the clinical use of implants with nanostructured calcium-incorporated surface may be beneficial in the posterior maxilla, under immediate loading protocol.

Early Bone Response to Dual Acid-Etched and Machined Dental Implants Placed in the Posterior Maxilla: A Histologic and Histomorphometric Human Study.

PURPOSE: To compare the early bone response to implants with dual acid-etched (DAE) and machined (MA) surface, when placed in the posterior human maxilla. MATERIALS AND METHODS: Fourteen patients received 2 implants in the posterior maxilla: 1 DAE and 1 MA. After 2 months, the implants were retrieved for histologic/histomorphometric evaluation. The bone-to-implant contact (BIC%), bone density in the threaded area (BDTA%), and the bone density (BD%) were calculated. The Wilcoxon matched-pairs signed rank test was used to evaluate differences (BIC%, BDTA%, and BD%) between the surfaces. RESULTS: In the MA implants, a mean (±SD) BIC%, BDTA%, and BD% of 21.76 (±12.79), 28.58 (±16.91), and 21.54 (±11.67), respectively, was reported. In the DAE implants, a mean (±SD) BIC%, BDTA%, and BD% of 37.49 (±29.51), 30.59 (±21.78), and 31.60 (±18.06), respectively, was reported. Although the mean BIC% of DAE implants value was almost double than that of MA implants, no significant differences were found between the 2 groups with regard to BIC% (P = 0.198) and with regard to BDTA% (P = 0.778) and BD% (P = 0.124). CONCLUSIONS: The DAE surface increased the periimplant endosseous healing properties in the native bone of the posterior maxilla.

Cellular Midpalatal Suture Changes after Rapid Maxillary Expansion in Growing Subjects: A Case Report.

The present case report aimed to investigate immediate histologic changes in midpalatal suture in humans following rapid maxillary expansion compared to control. Three patients (mean age 8.3 +/- 0.9 years) were enrolled in the case report and underwent midpalatal suture biopsy. Two patients underwent treatment before biopsy. The third patient did not show transversal maxillary deficiency and was enrolled as a control. Biopsy samples of midpalatal suture at 7 (subject 1) and 30 days (subject 2) after maxillary expansion as well as of one control (subject 3) were collected and processed for histology. In the control (subject 3) inter-digitations at the palatal suture gap were observed. At 7 days (subject 1) mature bone with small marrow spaces and trabecular bone with the peculiar storiform appearance inside the soft tissue and collagen fibers running parallel only in the central part were present. At 30 days (subject 2), a greater number of newly-formed bone trabeculae with a perpendicular orientation to the long axis of the suture could be seen. At 30 days the fibrous component of bone tissue was less represented compared to the sample at 7 days. Data from the preliminary histological results showed that bone formation was observed in the gap after rapid maxillary expansion, although the healing process was still ongoing.

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.

Esthetic assessment of immediately restored implants combined with GBR and free connective tissue graft.

AIM: Esthetic assessment of immediately restored implants combined with GBR and free connective tissue (CT) graft METHODS: A case-control, retrospective study involving 34 patients treated with maxillary anterior single implants, immediately placed and restored. Clinical and esthetic results were analyzed using standard clinical examination and a comprehensive index, comprising pink esthetic and white esthetic scores (PES/WES). The height of the implant crown and the corresponding height of the contralateral tooth crown were measured to identify mucosal recessions. The distance from the mucosal margin to the implant shoulder (DIM) was measured on the master model. RESULTS: Thirty of 34 implants fulfilled the strict success criteria set for dental implants with regard to osseointegration. Success was defined as implants with bone loss not exceeding 1.5 mm during the first year and loosing not more than 0.2 for each successive year. The other four implants were stable but did not meet the bone loss criteria mentioned above and defined as survived implants. Mean PES/WES was 14.44 ± 2.34 (range: 9-20). Mean PES was 7.12 ± 1.89 (range: 1-10). The highest mean values were achieved for the variable of root convexity/soft tissue color and texture (1.71 ± 0.46) whereas the mesial papilla (1.09 ± 0.62) proved to be the least pleasing. The mean WES was 7.32 ± 1.25 (range: 5-10). The difference between IC and contralateral TC was 0.54 mm. The mean value for the facial DIM was 3.82 ± 0.87 mm. CONCLUSIONS: An evaluation of soft and hard tissue augmentation in immediately restored immediate implant procedures was employed to obtain stable hard and soft tissues. The combined GBR and CT graft procedure achieved favorable peri-implant soft tissue condition and esthetic results. However, recession and incomplete papillas were frequently observed.

Is Low Serum Vitamin D Associated with Early Dental Implant Failure? A Retrospective Evaluation on 1625 Implants Placed in 822 Patients.

Aim. To investigate whether there is a correlation between early dental implant failure and low serum levels of vitamin D. Methods. All patients treated with dental implants in a single centre, in the period 2003-2015, were considered for enrollment in this study. The main outcome was early implant failure. The influence of patient-related variables on implant survival was calculated using the Chi-square test. Results. 822 patients treated with 1625 implants were selected for this study; 27 early failures (3.2%) were recorded. There was no link between gender, age, smoking, history of periodontitis, and an increased incidence of early failures. Statistical analysis reported 9 early failures (2.2%) in patients with serum levels of vitamin D > 30 ng/mL, 16 early failures (3.9%) in patients with levels between 10 and 30 ng/mL, and 2 early failures (9.0%) in patients with levels <10 ng/mL. Although there was an increasing trend in the incidence of early implant failures with the worsening of vitamin D deficiency, the difference between these 3 groups was not statistically significant (P = 0.15). Conclusions. This study failed in proving an effective link between low serum levels of vitamin D and an increased risk of early implant failure. Further studies are needed to investigate this topic.

The Effect of Crown-to-Implant Ratio on the Clinical Performance of Extra-Short Locking-Taper Implants.

BACKGROUND: The aim of the present prospective 5-year study was to evaluate the influence of crown-to-implant ratio (C/I ratio) on the survival, peri-implant marginal bone loss, and complications of extra-short (6.5 mm) locking-taper implants placed in the posterior areas of the jaw. METHODS: Over a 2-year period, all patients presenting with partial edentulism associated with vertical defects of the posterior alveolar ridges and sufficient bone volume to place extra-short (6.5 mm length × 5 mm diameter) implants were considered for inclusion in this study. RESULTS: Fifty-one patients (22 men, 29 women; aged between 40 and 75 years) were included in this study. Sixty-eight extra-short, locking-taper implants were placed to support 49 single crowns and 9 fixed partial dentures. The C/I ratio was <2 for 51 implants and ≥2 for 17 implants. All patients underwent the 5-year clinical examination. Two implants failed. Failure proportion was 2% in the C/I<2 group, and 6% in the C/I≥2 group: this difference was not statistically significant (P = 0.4). After 1 year of loading, a mean marginal bone loss of 0.29 and 0.39 was reported in the C/I<2 group and the C/I≥2 group, respectively. After 5 years of loading, a mean marginal bone loss of 0.38 and 0.48 was reported in the C/I<2 and C/I≥2 groups, respectively. The linear regression model failed to find a correlation between the C/I ratio and marginal bone loss along time, with a 0.023 mm (95% CI: -0.002; 0.048) increase in 1-year bone resorption for every 0.1 increase in C/I ratio (P = 0.07). At 5-year, the association reduced to 0.019 mm (P = 0.18). Only a few complications were reported. There was no statistically significant difference in the prevalence of biological (P = 0.9) complications between the 2 groups. Prosthetic complications were more frequent with C/I≥2 (12.5%) than with C/I<2 (6%), but this difference was not statistically significant (P = 0.6). CONCLUSIONS: Extra-short, locking-taper implants may be successfully used in the posterior areas of the jaw.

Evaluation of Volumetric Changes of Augmented Maxillary Sinus With Different Bone Grafting Biomaterials.

Extensive alveolar bone resorption because of pneumatized maxillary sinus is a common problem that limits dental implant placement. Maxillary sinus floor augmentation (MSFA) is an accepted treatment protocol that provides sufficient bone volume. The aim of this study was to evaluate the percentage of graft volume reduction following MSFA using cone beam computed tomography. In this retrospective study, cone beam computed tomography scans of MSFA were measured to evaluate the volume of the grafted sinus with deproteinized bovine bone (DBB), mineralized allograft (MA), or a mixture of MA and demineralized allograft as a composite. The volumetric changes in sinus augmentation between 2 weeks (T-I) and 6 months (T-II) after operation were analyzed. Thirty-nine patients were included in this study. The average percent volume reduction was 8.14 ±â€Š3.76%, 19.38 ±â€Š9.22%, and 24.66 ±â€Š4.68% for DBB, MA, and composite graft, respectively. A significant graft volume reduction was found between T-I and T-II for all groups (P < 0.01). The DBB group showed the least volume reduction (P < 0.01). Biomaterials can influence the bone graft volume change before implant placement. Deproteinized bovine bone may offer greater volume stability during healing than mineralized and composite allografts.

Quantitative Kinetics Evaluation of Blocks Versus Granules of Biphasic Calcium Phosphate Scaffolds (HA/ß-TCP 30/70) by Synchrotron Radiation X-ray Microtomography: A Human Study.

INTRODUCTION: Successful bone regeneration using both granules and blocks of biphasic calcium phosphate materials has been reported in the recent literature, in some clinical applications for maxillary sinus elevation, but the long-term kinetics of bone regeneration has still not been fully investigated. MATERIALS AND METHODS: Twenty-four bilateral sinus augmentation procedures were performed and grafted with hydroxyapatite/ß-tricalcium phosphate 30/70, 12 with granules and 12 with blocks. The samples were retrieved at different time points and were evaluated for bone regeneration, graft resorption, neovascularization, and morphometric parameters by computed microtomography and histology. RESULTS: A large amount of newly formed bone was detected in the retrieved specimens, together with a good rate of biomaterial resorption and the formation of a homogeneous and rich net of new vessels. The morphometric values were comparable at 5/6 months from grafting but, 9 months after grafting, revealed that the block-based specimens mimicked slightly better than granule-based samples the healthy native bone of the maxillary site. CONCLUSION: The scaffold morphology was confirmed to influence the long-term kinetics of bone regeneration.