To evaluate the influence of implant scanbody (ISB) material, position and operator on the accuracy of a confocal microscopy intraoral scanning (IOS) for complete-arch implant impression.
An ...edentulous maxillary model with 6 internal hexagonal connection analogues was scanned with an extraoral optical scanner to achieve a reference file. Three ISBs made of different materials (polyetheretherketone (Pk), titanium (T) and Pk with a titanium base (Pkt)) were scanned with IOS by 3 operators. The resulting 45 test files were aligned to the reference file with a best fit algorithm. Linear (ΔX, ΔY and ΔZ-axis) and angular deviations (ΔANGLE) were assessed. Absolute values of the linear discrepancies were summed up to obtain a global measure of linear absolute error (ΔASS). Influence of ISB material, position and operator was statistically assessed using the mixed general linear model.
At multivariate analysis, whenΔASS was considered as response variable, it was identified a significant influence of material (p<0.0001) and position (p=0.0009) while no significant operator effect was detected.
When ΔANGLE was considered as response variable, material and position significantly influenced the expected ΔANGLE (p=0.0232 and p<0.0001) and no operator effect was identified.
The investigated IOS for complete-arch digital impression was influenced by the ISB material with peek reporting the best results on both linear and angular measurements followed by titanium, peek-titanium resulting as the less accurate. Implant angulation affected significantly the linear deviations while implant position the angular deviations. Operator did not show any significant effect on the IOS accuracy.
Technologies for agro-industrial feedstock utilization such as pyrolysis, gasification and hydrothermal carbonization at industrial scale develop rapidly. The thermochemically converted biomasses of ...these production technologies have fundamentally different properties controlled by the production technology. This is reflected by general properties such as pH or elemental composition. The 13C NMR spectroscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy and black carbon results confirmed these observations showing that hydrochars have lower proportions of aromatic compounds than biochars (less stable) but are rich in functional groups (higher cation exchange capacity) than biochars. Analyses of pollutants indicate that polycyclic aromatic hydrocarbons as well as dioxin contents of most samples were under the threshold values recommended by International Biochar Initiative and European Biochar Certificate. In conclusion, biochars and hydrochars are entirely different from each other and these materials will probably have a complementary reaction in a soil environment.
•Production technologies influences fundamentally chemical properties of chars.•Carbonized materials have different behaviour in soil environment.•Environmental risk of chars is low with respect to PAH and dioxin contents.•Certification standard for biochars is not suitable for hydrochars.•Commercial scale reactors are able to produce high quality biochars according to the regulations of the EBC or IBI.
To introduce a proof of concept technique and new integrated workflow to optimize the functional and esthetic outcome of the implant-supported restorations by means of a 3-dimensional (3D) ...facially-driven, digital assisted treatment plan.
The Smiling Scan technique permits the creation of a virtual dental patient (VDP) showing a broad smile under static conditions. The patient is exposed to a cone beam computed tomography scan (CBCT), displaying a broad smile for the duration of the examination. Intraoral optical surface scanning (IOS) of the dental and soft tissue anatomy or extraoral optical surface scanning (EOS) of the study casts are achieved. The superimposition of the digital imaging and communications in medicine (DICOM) files with standard tessellation language (STL) files is performed using the virtual planning software program permitting the creation of a VDP.
The smiling scan is an effective, easy to use, and low-cost technique to develop a more comprehensive and simplified facially driven computer-assisted treatment plan, allowing a prosthetically driven implant placement and the delivery of an immediate computer aided design (CAD) computer aided manufacturing (CAM) temporary fixed dental prostheses (CAD/CAM technology).
The aim of this study was to systematically review the current scientific literature regarding the accuracy of fully guided flapless implant positioning for complete-arch rehabilitations in ...edentulous patients and to assess if there was any statistically significant correlation between linear deviation at shoulder point, at apex point and angular deviation. The electronic and manual literature search of clinical studies was carried out using specified indexing terms. A total of 13 studies were eligible for qualitative analysis and 277 edentulous patients were rehabilitated with 1556 implants patients by means of fully guided mucosa-supported template-assisted flapless surgery. Angular deviation was 3.42° (95% CI 2.82-4.03), linear deviation at shoulder point 1.23 mm (95% CI 0.97-1.49) and linear deviation at apex point 1.46 mm (95% CI 1.17-1.74). No statistically significant correlations were found between the linear and angular deviations. A statistically significant correlation was found between the two linear deviations (correlation coefficient 0.91) that can be summarized by the regression equation y = 0.03080 + 0.8254x. Computer-assisted flapless implant placement by means of mucosa-supported templates in complete arch restorations can be considered a reliable and predictable treatment choice despite the potential effects that flapless approach could bring to the overall treatment.
Physical weathering can modify the stability of biochar after field exposure. The aim of our study was to determine the potential carbon sequestration of the two chars at different timescales. We ...investigated the modification in composition and stability resulting from physical weathering of two different chars produced (i) at low temperature (250 °C) by hydrothermal carbonization (HTC); and (ii) at high temperature (1200 °C) by gasification (GS) using contrasting feedstocks. Physical weathering of HTC and GS placed on a water permeable canvas was performed through successive wetting/drying and freezing/thawing cycles. Carbon loss was assessed by mass balance. Chemical stability of the remaining material was evaluated as resistance to acid dichromate oxidation, and biological stability was assessed during laboratory incubation. Moreover, we assessed modification in potential priming effects due to physical weathering. Physical weathering induced a carbon loss ranging between 10 and 40% of the total C mass depending on the feedstock. This C loss is most probably related to leaching of small particulate and dissolved compounds. GS produced from maize silage showed the highest C loss. The chemical stability of HTC and GS was unaffected by physical weathering. In contrast, physical weathering strongly increased the biological stability of HTC and GS char produced from maize silage. After physical weathering, the half‐life (t1/2) of GS was doubled but only slight increase was noted for those of HTC. During the first weeks of incubation, HTC addition to soil stimulated native soil organic matter (SOM) mineralization (positive priming effect), while the GS addition led to protection of the native SOM against biologic degradation (negative priming effect). Physical weathering led to reduction in these priming effects. Model extrapolations based on our data showed that decadal C sequestration potential of GS and HTC is globally equivalent when all losses including those due to priming and physical weathering were taken into account. However, at century scale only GS may have the potential to increase soil C storage.
Abstract Statement of problem In patients with an altered skeletal maxillomandibular relationship and bone resorption, the rehabilitation of edentulous jaws by combining 4 implants, 2 straight ...medially and 2 tilted distally, may be preferred to avoid a bone augmentation procedure. Purpose The purpose of this single cohort 1-year prospective study was to evaluate the clinical performance of a 4-implant overdenture fully supported by a computer-aided designed/computer-aided manufactured (CAD/CAM) titanium bar. Material and methods This single cohort prospective study included edentulous participants rehabilitated with a 4-implant overdenture in 1 of the 2 jaws. The outcomes were implant and prosthetic survival and success rates, any biologic and technical complications, periimplant marginal bone loss, changes in the oral health impact profile (OHIP), bleeding on probing, and the plaque index. Results Eighteen participants received 72 implants. One year after implant placement, no implants or prosthesis had failed, and no biologic or technical complications had been observed. At the 1-year follow-up, the mean marginal bone loss was 0.29 ±0.16 mm. The OHIP summary scores demonstrated a significant improvement in oral health-related quality of life. At the 1-year follow-up, positive bleeding was found in 2 participants (11.1%) around 3 implants (4.1%). Three participants (16.6%), accounting for 5 implants (6.9%), showed a slight amount of plaque. Conclusions A 4-implant overdenture supported by a CAD/CAM titanium bar may be a reliable option for the treatment of the edentulous mandible and maxilla over a 1-year period. Oral health-related quality of life significantly improved in all treated participants.
Statement of problem In the posterior maxilla, tooth loss is usually associated with alveolar bone resorption and sinus pneumatization, limiting the placement of implants without grafting procedures. ...Purpose The purpose of this study was to evaluate a minimally invasive treatment of the atrophic posterior maxilla, with axial and tilted implants and immediate loading. The research hypothesis was that the combination of a guided, minimally invasive approach and the biomimetic features of computer-aided design and computer-aided manufacturing (CAD/CAM) abutments would be an effective alternative to maxillary sinus floor augmentation procedures with reduced bone resorption around implants. Material and methods Twenty-seven consecutive participants (female=12, male=15) (mean age 54.18 years) with severe atrophy of the posterior maxilla were treated by using guided surgery with immediately loaded axial (39) and tilted (42) implants supporting CAD/CAM zirconia (39) and titanium (42) abutments (81 total) and partial fixed prostheses. Each participant underwent a computed tomography scan, after which 2 or 3 implants were positioned with a flapless or miniflap approach. The drilling protocol was adapted to the bone density of each implant site to obtain an insertion torque ranging between 40 and 50 Ncm. CAD/CAM customized abutments composed of zirconia or titanium were fixed to the implants with prosthetic screws tightened with a torque of 35 Ncm. An acrylic resin interim restoration reinforced with metal was placed immediately. Five to 6 months after initial loading, a zirconia framework was manufactured, and a definitive prosthesis was placed. Clinical and radiological controls were performed at baseline and after 1 and 3 years to assess implant and prosthesis survival and success rate and compare marginal bone remodeling of axial and tilted implants. Inferential statistics for radiological data were acquired by using the Mann-Whitney U-test. All statistical comparisons were conducted at the .05 significance level. Results The mean follow-up period was 43.3 months (ranging from 36 months to 54 months). The cumulative implant survival rate was 96.3% at 3 years. All prosthetic restorations were stable and in good function, resulting in a cumulative prosthetic survival rate of 100%. Three restorations had chipping of the veneer material; thereafter, the cumulative prosthetic success rate was 91.9%. Conclusions Treatment of the posterior partially edentulous atrophic maxilla with guided surgery and immediate loading of tilted and straight implants supporting short-span partial fixed dental prostheses is effective.
Incidence of ulcerative colitis (UC) in elderly population is increasing because of ageing and because of its minimal impact on life span. Data on natural history, outcomes and therapeutic strategies ...are limited. Our aim is to characterize UC in elderly-onset patients followed at our Inflammatory Bowel Disease outpatient clinic and compare with adult-onset UC.
From January 2000 to June 2019, 94 patients with UC diagnosed after the age of 65 years (elderly group, E-O) were identified and matched 1-1 according to gender and calendar year of diagnosis with patients diagnosed with UC at age between 40 and 64 years (adult age, A-O).
Comorbidity Index (3.8 vs 1.6, p < 0.0005) was higher for elderly UC patients. Symptoms at presentation were similar between the two groups, although abdominal pain was more common in adults, and weight loss was more common in the elderly. At diagnosis, left colitis (61% vs 39%) and proctitis (14% vs 26%) (p = 0.011) were more frequent in the elderly. Therapy and clinical behaviour were similar. Surgery was more frequently performed in the elderly (20% vs 9%, p = 0.02), while biological therapy was less used (2.1% vs 22%, p < 0.0005). Complications were more frequent in the elderly. Extraintestinal manifestations were lower in elderly patients (9.6% vs 19.2%, p = 0.061). Time to first relapse was similar between the two groups. Mortality (p < 0.0005) was higher in elderly patients.
Ulcerative Colitis has similar presentation and behaviour in elderly and adults patients. However, the elderly are more fragile because of comorbidities, increased risk of infections and disease-related complications.
Purpose: To assess and compare the accuracies of intraoral scanners (IOS) and stereophotogrammetry (SPG) devices for complete-arch digital implant impressions.Methods: A 4-analog model was digitized ...using a desk scanner to obtain a reference file. Thirty test scans were conducted using the investigated IOS device, while an additional 30 scans were performed using the SPG device. Using the best-fit algorithm, the resulting 60 test files were aligned with the reference file. Linear (ΔX, ΔY, and ΔZ-axis) and angular deviations (ΔANGLE) were evaluated. Three-dimensional (3D) deviation was calculated based on the Euclidean distance (ΔEUC). The analysis was stratified according to the scanning device and implant position. Fisher’s F and t-tests were used to compare the variances and expected values of the two scanning systems.Results: IOS expressed a higher 3D (ΔEUC) mean deviation than SPG (52.8 µm vs. 33.4 µm, P < 0.0001), with extreme measurements up to 181.9 µm. A significantly higher standard deviation (SD) was associated with IOS (37.1 µm vs. 17.7 µm, P < 0.0001). Considering angular deviations, the IOS showed slightly higher angular mean deviations (ΔANGLE) than the SPG (0.28° vs. 0.24°, P = 0.0022), with extreme measurements of up to 0.73°. The SPG SD values were significantly lower than the IOS SD values (0.14° vs. 0.04°, P < 0.0001).Conclusions: The SPG showed significantly higher 3D and angular accuracies for complete arch implant impressions, with consistent repeatability. IOS scanning revealed significantly higher extreme deviations exceeding the acceptable threshold value. Despite study limitations, SPG appears more feasible than IOS for complete-arch digital implant impressions.
To introduce a digitally assisted technique to achieve the ideal soft and bone tissue interface for anatomic-driven pink free implant supported fixed prosthesis, and prefabricate an interim ...prosthesis to be used the day of the surgery as a prosthetic scaffold to condition the healing.
The digital assisted soft tissue sculpturing (DASS) technique allows the previsualization of the ideal soft and bone tissue interface and fabricate a computer aided design computer aided manufacturing (CAD-CAM) anatomic-driven pink free complete arch interim prosthesis for the immediate loading. Bone and soft tissue interface as well as the interim prosthesis design are performed in a segmented multiple standard tessellation language (STL) file embedding the bone anatomy, the intraoral surface anatomy (dental and soft tissue), the digital wax-up and the implant positioning. The interim prosthesis is used as a prosthetic scaffold to guide the soft and bone tissue surgical sculpturing and regeneration.
The DASS technique is a predictable integrated digital workflow that simplifies the achievement of a scalloped tissue interface for pink free fixed implant prosthesis, reestablishing the mucosal dimension required for the protection of underlying bone while maintaining tissue health. The surgical sculpturing and maturation of the soft and bone tissue is driven and enhanced by the xenogeneic collagen matrix grafting and prosthetic scaffold effect of the digitally prefabricated interim prosthesis delivered the day of the surgery.
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