67 research outputs found
The use of platelet rich plasma in maxillary sinus augmentation. Biologic principles and clinical studies
No full textL’utilizzo del concentrato piastrinico nel rialzo del seno mascellare. Principi biologici e studi clinici
No full textTurbidite channel-levée transitions: insights from the Tachrift system (Complex 6, Taza-Guercif Basin, NE Morocco)
No full textThis contribution reports on the outcrop of one (Complex 6, hereafter) of multiple turbidite channel-levée complexes making the Tachrift system (Late Tortonian- early Messinian), beautifully exposed in NE Morocco as part of the clastic fill of the Taza-Guercif Basin. Geological mapping was integrated with facies analysis on 46 logs and physical stratigraphic correlations. Complex 6 consists of three sandstone-rich units labelled A, B, and C that progressively increase in grain-size and are laterally stacked in a SE-ward shifting fashion. Particularly, channel- fills and correlative levées of Units B and C have contrasting architectural styles which likely reflect changes in flow parameters (e.g., grain size, volume, density stratification etc.), channel sinuosity, and morphodynamics. Owing to magnificent 3D exposures, the ongoing study of Complex 6 outcrops will provide sedimentological characterization of channel-fills and correlative levée deposits, insights into evolution of their parent channel from inception trough abandonment, and sub-seismic lithological calibration of subsurface analogues
Possibilita’ terapeutiche e risultati a lungo termine degli innesti di apposizione orizzontale
No full textLate Quaternary sedimentation and tectonics in the Po Basin: field evidences at the Po Plain-Apennines border (Lombardy)
No full textTopographic reliefs and terraced landscapes represent key-sectors to constrain recent geological evolution and subsurface stratigraphy in almost flat landscapes like the Quaternary Po Plain. Aiming to investigate the role of Late Quaternary tectonics on the complexity of stratigraphic and geomorphological features exposed at the Po Plain-Apennines border in Lombardy, we focus on a structural culmination of the Emilia salient, the San Colombano Hill ramp anticline.
Geological and geomorphological mapping at 1:10.000 scale, stratigraphic, sedimentological, paleontological, petrographic and morpho-structural analyses, complemented by C14 and OSL age determinations, show the incremental tectonic imprints on the Quaternary stratigraphy originating the present-day palimpsest landscape. Location of unconformable stratigraphic vs. conformable morphological boundaries, pinch-out and cross-cut relationships among alluvial sedimentary bodies, uplifted paleovalley fills, cannibalism of pre-existing alluvial clastics, colluvial wedges and sediment deformation structures highlight how, where and when tectonic-driven processes controlled the evolution of the Hill and the adjacent plain.
The S. Colombano ramp anticline underwent Early-Middle Pleistocene thrusting, which uplifted and folded the Gelasian regional unconformity between littoral Calabrian and deep-marine Miocene formations. Late Pleistocene, alpine-sourced alluvial and glacio-fluvial units, terraced the deformed marine succession through the composite Late Pleistocene unconformity. The mapped synthems progressively wedge, thin and amalgamate S-wards, suggesting the syn-sedimentary confinement by an uplifting mild relief ancestor of the present-day Hill. Relicts of syn-tectonic paleo-valley fills testify the first drainage pattern of this proto-hill, where also polycyclic loess-soil aggraded during early Late Pleistocene.
The S. Colombano structure underwent dissection since latest Pleistocene along three fault systems, while LGM glacio-fluvial and alluvial units prograded from the NW. Evidences of Latest Pleistocene fault activity are observed as thickness variations of the LGM synthem, offset of the Late Pleistocene unconformity, paleosol reworking in colluvial wedges on the fault-block hangingwalls, marked by triangular facets and abrupt diversions of the river network. A late-LGM muddy flood plain developed N of the hill, owing to tectonic-induced subsidence. This was cross-cut by the meandering tributaries of the paleo-Po River during the Late Glacial. The post-glacial-Holocene entrenchment of the river network and river anomalies suggest an eventual latest phase of uplift and transtension of the San Colombano structure, plausibly related to the ongoing N-wards propagation of the Emilia salient. The progressing research is integrating the surface and subsurface field geological and evolutionary constraints into 3D(4D) geological models, as the basis for hydrogeological and geohazard applications
Immediate rehabilitation of the completely edentulous jaws with fixed prostheses supported by upright and tilted implants : a multicenter clinical study
No full textPurpose: The aims of this study were to assess the treatment outcome of immediately loaded full-arch screw-retained prostheses with distal extensions supported by both upright and tilted implants for the rehabilitation of edentulous jaws and to compare the outcomes of upright versus tilted implants. Materials and Methods: At 4 study centers, 342 Osseotite NT implants were consecutively placed in 65 patients (96 implants were placed in 24 mandibles and 246 implants in 41 maxillae). The 2 distal implants were tilted by 25 to 35 degrees. Provisional full-arch restorations made of a titanium framework and acrylic resin teeth were delivered within 48 hours of surgery and immediately loaded. The final prosthesis was delivered after 3 months of healing. Results: Three implants failed during the first year and another 2 within 18 months of loading in the maxilla. The cumulative implant survival rate for the maxilla was 97.59% for up to 40 months of follow-up. No implant failure was recorded for the mandible. The prosthetic success rate was 100%. Marginal bone loss around upright and tilted implants was similar. Patients were satisfied of their esthetics, phonetics, and function. Conclusion: The preliminary results of this study suggest that immediate rehabilitation of the edentulous maxilla and mandible by a hybrid prosthesis supported by 6 or 4 implants, respectively, may represent a viable treatment alternative with respect to more demanding surgical procedures. The clinical results indicate that immediately loaded tilted implants may achieve the same outcome as upright implants in both jaws
Il carico immediato nei mascellari totalmente edentuli mediante impianti inclinati : studio clinico prospettico multicentrico
No full textComparative results of single implants with and without laser-microgrooved collar placed and loaded with different protocols: a long-term (7 to 10 years) retrospective multicenter study
No full textPURPOSE: This nonrandomized, retrospective multicenter study aimed to evaluate success rates, peri-implant marginal bone loss, and clinical parameters around single implants with and without laser-microgrooved collars placed and loaded using different protocols after 7 to 10 years of function. MATERIALS AND METHODS: A chart review was used to select patients treated at five private dental clinics with single dental implants with and without laser-microgrooved collars. Cumulative success rates, peri-implant marginal bone loss, probing depth, Plaque Index, bleeding on probing, and gingival recession were recorded at baseline examinations (ie, definitive restoration delivery) and at each year during the follow-up period. RESULTS: Three hundred single implants (140 without laser-microgrooved collars and 160 with 1.7-mm laser-microgrooved collars) in 300 patients were selected. At the completion of the study period, 26 patients and 26 implants (17 with and 9 without a laser-microgrooved collar) were classified as "dropouts." Implants and restorations were categorized into two subgroups each for a total of four study groups: group 1, immediate implant placement; group 2, delayed implant placement; group 3, immediate nonocclusal loading of prostheses; and group 4, delayed loading of prostheses. Nineteen implants (6.9%) failed clinically (4 [2.7%] with and 15 [11.4%] without a laser-microgrooved collar). The difference in cumulative success rates was statistically significant (P < .05). Radiographically, at the end of the follow-up period, the laser-microgrooved group showed a mean peri-implant marginal bone loss of 0.64 mm compared with 1.82 mm for the non-laser-microgrooved group. At the same time point, a mean probing depth of 0.76 mm was observed for the laser-microgrooved group compared with 2.75 mm for the non-laser-microgrooved group. A statistically significant difference in peri-implant marginal bone loss and probing depth between the two types of implant collars was evident (P < .05). No statistically significant correlation was noted between the types of implant placement/prosthetic restoration and clinical parameters. CONCLUSION: Implants with a laser-microgrooved collar appear to influence the peri-implant soft and hard tissue stability, reducing the probing depth levels and the peri-implant marginal bone loss by more than 50% after 10 years of function, regardless of the type of implant placement and loading protocol
The channel-levée transition: insights from the Tachrift Turbidite System (Complex T6, Taza-Guercif Basin, NE Morocco)
No full textTurbidite channel-levée complexes have been the focus of research over more than forty years. Although high-resolution 3D seismic yielded detailed imaging of these deposits, facies transition from channel to correlative levée remains elusive. To fill this gap, extensive and well-exposed outcrops are important, as they provide information on fine-scale facies heterogeneity. Despite this, documented outcrops where accordant channel fills and overbank sediments can be observed with continuity are relatively few/small. We present the Tachrift Project aimed at the field-based reconstruction of the Tachrift Turbidite System (Tortonian-Early Messinian) in the Taza-Guercif Basin (Rifian Corridor, NE Morocco). Among the 9 superimposed, spectacularly exposed channel-levée complexes (T1 to T9) filling the basin for a total 600 m thickness, here we focus on the T6 complex. Detailed geological mapping was integrated with measurements and facies analysis on 46 logs, and physical stratigraphic correlations. T6 (12 m thick) is bounded above and below by 3 to 10 m-thick mudstone units. It consists of three stacked sandstone-rich units that are separated by erosional surfaces. Each unit comprises peculiar, physically traced facies associations showing different channel-levée transitions. They reveal an eastward channel belt migration and a progressive flow energy/density increase. Benefitting from 3D great exposures, the ongoing project provides i) characterization and correlation of channels and accordant overbank sediments, ii) insights on evolution of a channel-levée complex from inception to its deactivation, iii) sub-seismic scale lithological and architectural calibration for analogue subsurface deposits
A 5-year report from a multicentre randomised clinical trial : immediate non-occlusal versus early loading of dental implants in partially edentulous patients
No full textPURPOSE: To compare peri-implant bone and soft-tissue levels of immediately non-occlusally loaded versus non-submerged early loaded implants in partially edentulous patients 5 years after implant placement. MATERIALS AND METHODS: Fifty-two patients were randomised in five Italian private practices: 25 in the immediately loaded group and 27 in the early loaded group. To be immediately loaded, single implants had to be inserted with a torque of > 30 Ncm, and splinted implants with a torque of > 20 Ncm. Immediately loaded implants were provided with non-occluding temporary restorations within 48 hours. After 2 months, the provisional restorations were put in full occlusion. Implants were early loaded after 2 months. Final restorations were provided 8 months after implant placement. Outcome measures were prosthesis and implant failures as well as biological and prosthetic complications recorded by non-blinded assessors. Blinded assessors evaluated peri-implant bone and soft-tissue levels. RESULTS: Fifty-two implants were immediately loaded and 52 early loaded. One patient of the early loaded group dropped out after the 1-year recall. One single immediately loaded implant failed 2 months after placement. Only one complication (iatrogenic peri-implantitis) occurred in one patient of the early loading group. Both groups gradually lost peri-implant bone in a highly statistically significant way at 2, 8 and 14 months and at 4 and 5 years. After 5 years, patients of both groups had lost an average of 1.2 mm of peri-implant marginal bone. There were no statistically significant differences in peri-implant bone and soft-tissue level changes between the 2 groups. At 5 years, there was a statistically significant recession (0.2 mm) of the vestibular soft tissues from baseline (delivery of the final restorations 8 months after implant placement) only for immediately loaded implants. CONCLUSIONS: In well maintained patients, complications are uncommon and healthy and stable periimplant tissues can be maintained for 5 years around immediately and early loaded implants
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