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OBJECTIVE: This study evaluated the ability of mid-regional proadrenomedullin (MR-proADM) to identify disease severity in Coronavirus disease 2019 (COVID-19) patients in comparison to conventional inflammatory biomarkers and clinical scores. PATIENTS AND METHODS: In an observational trial, COVID-19 acute respiratory distress syndrome (ARDS) patients were enrolled. MR-proADM, C-reactive protein (CRP), procalcitonin (PCT) and lactic acid (LA) were measured in all patients at admission (T0), at 24 hours (T1) and in the third (T3) and fifth day (T5) of hospitalization. The aims of this study were to determine the role of MR-proADM to detect patients with high risk of mortality and compare the prognostic value of MR-proADM with commonly used clinical scores (Sequential Organ Failure Assessment score - SOFA score, Acute Physiologic Assessment and Chronic Health Evaluation II score - APACHE II score, and Simplified Acute Physiological score II - SAPS II score). RESULTS: Twenty-one COVID-19 ARDS patients admitted to the Intermediate Care Unit (IMCU) were enrolled. The median MR-proADM values were 2.28, 2.41, 1.96 and 1.89 nmol/L at T0, T1, T3 and T5, respectively. The 30-day all-cause mortality rate was 52.4%. Mean MR-proADM T0 value was significantly higher in non-survivors compared with survivors (3.5 vs. 1.1 nmol/L, p < 0.05). No significant differences were found for the other inflammatory biomarkers. In terms of the area under the receiver-operating characteristic curve (AUC), MR-proADM showed a similar discriminatory power compared with APACHE II, SOFA and SAPS II score (0.81, 0.91, 0.70 and 0.78, respectively). The optimal MR-proADM cut-point cut-off point was 1.07 nmol/L, which corresponds to a sensitivity of 91% and a specificity of 71%. CONCLUSIONS: MR-proADM, in addition to the clinical scores, could be useful to predict outcome in COVID-19 ARDS patients.
Subject(s)
Adrenomedullin/blood , COVID-19/blood , Protein Precursors/blood , SARS-CoV-2 , Severe Acute Respiratory Syndrome/blood , APACHE , Biomarkers/blood , C-Reactive Protein/analysis , COVID-19/mortality , Humans , Italy , Organ Dysfunction Scores , Prognosis , ROC Curve , Severe Acute Respiratory Syndrome/mortality , Severe Acute Respiratory Syndrome/virologyABSTRACT
Human brain activity allows to anticipate future events and to prepare the next action accordingly; consistently, event-related potential (ERP) studies found action preparatory brain activities in the premotor and prefrontal cortex. In the present study, we investigated the preparatory activity in the sensory cortical regions. Slow cortical potentials were recorded during passive tasks, i.e., subjects expected for a sensory stimulus and no motor or cognitive response were required. In particular, we tested the hypothesis that perceptual anticipatory cortical mechanisms were modality specific. Three groups of 21 young adults underwent passive perceptual tasks in different sensory modalities (visual, auditory, or somatosensory). We confirmed the presence of a visual negativity (vN) component for the visual modality starting about 800 ms before stimulus with source in extrastriate areas and we found novel modality-specific sensory readiness components for the auditory and somatosensory modalities. The auditory positivity (aP) started about 800 ms before stimulus with source in bilateral auditory cortices and the somatosensory negativity (sN) started about 500 ms before stimulus with source in the somatosensory secondary cortex, contralateral to the stimulated hand. The scalp topography and intracranial sources of these three slow preparatory activities were mirrored with inverted polarity at early post-stimulus stage evoking the well-known visual P1, auditory N1, and somatosensory P100 components. Present findings contribute to widening the family of slow wave preparatory components, providing evidence about the relationship between top-down and bottom-up processing in sensory perception.
Subject(s)
Anticipation, Psychological/physiology , Cerebral Cortex/physiology , Evoked Potentials , Perception/physiology , Adult , Auditory Cortex/physiology , Auditory Perception/physiology , Electroencephalography , Female , Humans , Male , Physical Stimulation , Somatosensory Cortex/physiology , Touch Perception/physiology , Visual Cortex/physiology , Visual Perception/physiology , Young AdultABSTRACT
In the present study, we investigated neural correlates associated with gender differences in a simple response task (SRT) and in a discriminative response task (DRT) by means of event-related potential (ERP) technique. 120 adults participated in the study, and, based on their sex, were divided into two groups matched for age and education level. Behavioral performance was assessed with computing response speed, accuracy rates and response consistency. Pre- and post-stimulus ERPs were analyzed and compared between groups. Results indicated that males were faster than females in all tasks, while females were more accurate and consistent than males in the more complex tasks. This different behavioral performance was associated with distinctive ERP features. In the preparation phase, males showed smaller prefrontal negativity (pN) and visual negativity (vN), interpreted as reduced cognitive preparation to stimulus occurrence and reduced reliance on sensory proactive readiness, respectively. In the post-stimulus phase, gender differences were present over occipital (P1, N1, P2 components) and prefrontal (pN1, pP1, pP2 components) areas, suggesting allocation of attentional resources at distinct stages of information processing in the two groups. Overall, the present data provide evidence in favor of a more proactive and cautious cognitive processing in females and a more reactive and fast cognitive processing in males. In addition, we confirm that (1) gender is an important variable to be considered in ERP studies on perceptual processing and decision making, and (2) the pre-stimulus component analysis can provide useful information concerning neural correlates of upcoming performance.
Subject(s)
Brain/physiology , Psychomotor Performance , Adult , Electroencephalography , Evoked Potentials , Female , Humans , Inhibition, Psychological , Male , Reaction Time , Sex Factors , Visual Perception/physiologyABSTRACT
Proactive brain control optimizes upcoming actions and inhibits unwanted responses. In the present event-related potential (ERP) study, participants freely decided in advance whether to respond or not to an upcoming stimulus, then prepared or not the action according to their decision; finally, a stimulus was delivered, and subjects had to respond (or not). During the decision-making stage, a prefrontal negativity raised bilaterally in case no-response was decided, reflecting the first brain signal of proactive inhibition. Simultaneously, slow activity raised over premotor cortices independently from the decision taken, and then raised during the preparation phase only in the case of response decision (as a sort of accelerator). When the decision was not to respond, the prefrontal activity remained sustained (as a sort of brake) and showed a right-lateralized distribution during the preparation phase. Overall, we described the time-course of a proactive accelerating-braking system regulating self-control of actions.
Subject(s)
Brain/physiology , Psychomotor Performance/physiology , Self-Control , Decision Making/physiology , Electroencephalography , Evoked Potentials/physiology , Female , Humans , Male , Young AdultABSTRACT
In this study the LCA methodology is applied in order to satisfy two goals: i) to evaluate the hot spots in site-specific production chain of biodiesel from terrestrial and micro-algae feedstock; ii) to compare quantitatively, utilizing primary data, the impacts of the first generation in respect to the third generation bio-fuels. Results show that micro-algae are neither competitive yet with traditional oil crops nor with fossil fuel. The use of renewable technologies as photovoltaics and biogas self production might increase the competitiveness of micro-algae oil. Further investigations are however necessary to optimize their production chain and to increase the added value of co-products.
Subject(s)
Biofuels , Crops, Agricultural , Environment , Fossil Fuels , TechnologyABSTRACT
Research on preparatory brain processes taking place before acting shows unexpected connections with cognitive processing. From 50 years, we know that motor-related brain activity can be measured by electrocortical recordings 1-3s before voluntary actions. This readiness potential has been associated with increasing excitably of premotor and motor areas and directly linked to the kinematic of the upcoming action. Now we know that the mere motor preparation is only one function of a more complex preparatory activity. Recent research shows that before any action many cognitive processes may occur depending on various aspects of the action, such as complexity, meaning, emotional valence, fatigue and consequences of the action itself. In addition to studies on self-paced action, the review considers also studies on externally-triggered paradigms showing differences in preparation processes related to age, physical exercise, and task instructions. Evidences from electrophysiological and neuroimaging recording indicate that in addition to the motor areas, the prefrontal, parietal and sensory cortices may be active during action preparation to anticipate future events and calibrate responses.
Subject(s)
Cognition , Brain Mapping , Contingent Negative Variation , Electroencephalography , Humans , Motor Cortex , MovementABSTRACT
We compared the effect of locking the event-related potentials (ERPs) on the stimulus vs. the response in a simple (SRT) and in a discriminative (DRT, equally probable Go/No-go) visuo-motor task. The accurate alignment of stimulus- and response-locked ERPs on the same time scale was obtained selecting a group of 27 participants with low inter-individual response time (RT) variation in the two tasks to reduce the jitter of RTs. Two-second epochs were defined for the analyses based on averaged RTs in the two tasks. Results show that the preparatory pre-stimulus activities (i.e., the pN and the BP components) were not affected by the different locking in both SRT and DRT. As expected, the exogenous post-stimulus P1 and N1 components (and the P2, present only in SRT) were larger in stimulus- than response-locked averaging; the same trend was observed for the less-known prefrontal N1 and P1 components (pN1 and pP1) that were larger in stimulus-locked averaging (the effect was not significant in SRT). The prefrontal pP2 component was only present in DRT peaking around 370 ms, and did not show an effect of locking. The frontal-central N2 component was enhanced by response-locked averaging in SRT, while it did not show effects of locking in DRT. The P3 component peaked at about 350ms over central sites in SRT, and at about 500ms over parietal sites in DRT; in both cases its amplitude was larger in response- than in stimulus-locked averaging. Overall, the amplitude of the preparatory components was independent from locking, the exogenous components were enhanced by stimulus locking, and the late components were more related to the response than to the stimulus. Concluding, to investigate action preparation, perception, and perceptual-decisional activity ERP studies should adopt stimulus-locked averaging with an appropriate baseline and longer pre-stimulus interval, or use both types of locking.
Subject(s)
Evoked Potentials/physiology , Photic Stimulation , Reaction Time/physiology , Task Performance and Analysis , Adult , Electroencephalography , Female , Humans , Male , Middle Aged , Young AdultABSTRACT
The reactions of 1,3,5-triaminobenzene derivatives with 2,3,4-trinitrothiophene and 2-bromo-3,4,5-trinitrothiophene gave new all-conjugated compounds bearing both an electron-withdrawing and an electron-donor moiety on the same unit. The reactions with 2,3,4-trinitrothiophene offered evidence, by NMR spectroscopy at low temperature, of the formation of new labile Wheland-Meisenheimer intermediates whereas at room temperature stable unexpected products derived from the attack of the nucleophile at C-4 with replacement of the nitro group were isolated. Their formation caused, in turn, the obtainment of a salt between 1-nitroso-2,4,6-triaminobenzenes and 2,4-dinitrothiophen-3-ol. The reactions with 2-bromo-3,4,5-trinitrothiophene produced in good yields the SNAr substitution product with the displacement of the bromide. All the new coupling products obtained are of applicative interest, considering the increasing concern for highly conjugated π-systems in solar energy conversion or optoelectronic devices.
ABSTRACT
Studies on perceptual decision-making showed that manipulating the proportion of target and non-target stimuli affects the behavioral performance. Tasks with high frequency of targets are associated to faster response times (RTs) conjunctively to higher number of errors (reflecting a response bias characterized by speed/accuracy trade-off) when compared to conditions with low frequency of targets. Electroencephalographic studies well described modulations of post-stimulus event-related potentials as effect of the stimulus probability; in contrast, in the present study we focused on the pre-stimulus preparatory activities subtending the response bias. Two versions of a Go/No-go task characterized by different proportion of Go stimuli (88% vs. 12%) were adopted. In the task with frequent go trials, we observed a strong enhancement in the motor preparation as indexed by the Bereitschaftspotential (BP, previously associated with activity within the supplementary motor area), faster RTs, and larger commission error rate than in the task with rare go trials. Contemporarily with the BP, a right lateralized prefrontal negativity (lateral pN, previously associated with activity within the dorsolateral prefrontal cortex) was larger in the task with rare go trial. In the post-stimulus processing stage, we confirmed that the N2 and the P3 components were larger for rare trials, irrespective of the Go/No-go stimulus category. The increase of activities recorded in the preparatory phase related to frequency of targets is consistent with the view proposed in accumulation models of perceptual decision for which target frequency affects the subjective baseline, reducing the distance between the starting-point and the response boundary, which determines the response speed.
Subject(s)
Anticipation, Psychological/physiology , Prefrontal Cortex/physiology , Probability , Decision Making/physiology , Electroencephalography , Evoked Potentials , Female , Humans , Male , Photic Stimulation , Psychomotor Performance/physiology , Reaction Time , Visual Perception/physiology , Young AdultABSTRACT
Nowadays computer-guided "flap-less" surgery for implant placement using stereolithographic tem-plates is gaining popularity among clinicians and patients. The advantages of this surgical protocol are its minimally invasive nature, accuracy of implant placement, predictability, less post-surgical discomfort and reduced time required for definitive rehabilitation. Aim of this work is to describe a new protocol (Smart Fusion by Nobel Biocare), thanks to which is now possible to do a mini-invasive static guided implant surgery, in partially edentulous patients with at least 6 remaining teeth, without the use of a radiographic guide. This is possible thanks to a procedure named surface mapping based on the matching between numerous points on the surface of patient's dental casts and the corresponding anatomical surface points in the CBCT data. The full protocol is examined focusing the attention on the clinical and laboratory procedures. CONCLUSIONS: Also with some critical points and needing an adequate learning curve, this protocol allows to select the ideal implant position in depth, inclination and mesio-distal distance between natural teeth and or other implants enabling a very safe and predictable rehabilitation compared with conventional surgery. It represents a good tool for the best compromise between anatomy, function and aesthetic, able to guarantee better results in all clinical situations.
ABSTRACT
PURPOSE: This study describes the ability to perform a technique for bone regeneration in maxillary posterior deficit (TGSL) without the use of bone grafting materials using a highly minimally invasive protocol. MATERIALS AND METHODS: Sixty six implants have been inserted in the sinus floor of a total of 39 patients through the transcrestal guided sinus lift technique (TGSL). All patients have been followed for at least three years in function. The drilling protocol was adapted on the basis of bone density of each implant site to achieve a torque between 45 and 55 Ncm. Healing titanium abutments tightened to 35 Ncm have been used. A CAD/CAM metal ceramics final prosthetic restoration has been generated a six months after the tissues healing and the provisional functionalization of the occlusion. Survival rate of implants and prostheses, biological and biomechanical complications, changes in marginal bone levels, and total height of alveolar crest bone before and after surgery have been evaluate and measured by the results obtained in this prospective study. It was also measured the periodontal parameters as well as levels of perception of pain by the patient during the entire recovery period. RESULTS: The result of the data of follow-up was 41.96 (24 to 36) months. Cumulative implant survival was 98.53% at 3 years. There were no biological and mechanical complications and there were no prosthetic failures during the whole period of follow-up. The Marginal Bone Loss (MBL) average during the first year of operation was from 0.33 to 0.36 mm, while the 3-year follow-up, the MBL average was 0.51 to 0.29 mm. The average of residual bone height of alveolar ridge before treatment was 6.7 to 1.6 mm (range 5.1 to 9.2 mm), while the average bone height was gained 6,4 - 1.6 mm (range 3.2 to 8.1 mm). All patients reported lower pain levels and found to have normal periodontal parameters. CONCLUSIONS: This study suggests that the use of guided surgery to perform transcrestal maxillary sinus lift to increase the sub-antral crestal height is a minimally invasive technique of success for the short and medium-term of follow-up, thus avoiding the extended treatment time and reducing the morbidity associated with the lifting of the floor of the maxillary sinus with traditional technique using bone grafting materials. Furthermore, this protocol without the use of graft materials does not vary the final outcome that have demonstrated the presence of newly formed bone around implants offering always predictable results, and giving a further reduction in the costs of the procedure rehabilitation.
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OBJECTIVE: Data about endocrine and bone disease in nontransfusion-dependent thalassaemia (NTDT) is scanty. The aim of our study was to evaluate these complications in ß-TI adult patients. METHODS: We studied retrospectively 70 ß-TI patients with mean followup of 20 years. Data recorded included age, gender, haemoglobin and ferritin levels, biochemical and endocrine tests, liver iron concentration (LIC) from T2*, transfusion regimen, iron chelation, hydroxyurea, splenectomy, and bone mineralization by dual X-ray absorptiometry. RESULTS: Thirty-seven (53%) males and 33 (47%) females were studied, with mean age 41 ± 12 years, mean haemoglobin 9.2 ± 1.5 g/dL, median ferritin 537 (range 14-4893), and mean LIC 7.6 ± 6.4 mg Fe/g dw. Thirty-three patients (47%) had been transfused, occasionally (24/33; 73%) or regularly (9/33; 27%); 37/70 (53%) had never been transfused; 34/70 patients had been splenectomized (49%); 39 (56%) were on chelation therapy; and 11 (16%) were on hydroxyurea. Endocrinopathies were found in 15 patients (21%): 10 hypothyroidism, 3 hypogonadism, 2 impaired glucose tolerance (IGT), and one diabetes. Bone disease was observed in 53/70 (76%) patients, osteoporosis in 26/53 (49%), and osteopenia in 27/53 (51%). DISCUSSION AND CONCLUSIONS: Bone disease was found in most patients in our study, while endocrinopathies were highly uncommon, especially hypogonadism. We speculate that low iron burden may protect against endocrinopathy development.
Subject(s)
Bone Diseases/complications , Endocrine System Diseases/complications , beta-Thalassemia/complications , Adult , Bone Diseases, Metabolic/complications , Female , Humans , Male , Osteoporosis/complicationsABSTRACT
AIM: Aim of the study was to review our experience with fenestrated and branched stent-grafts to treat juxtarenal (JAA) and thoracoabdominal (TAAA) aortic aneurysms after previous open or endovascular aortic surgery. METHODS: A prospectively maintained database including all consecutive patients with JAA or TAAA treated with fenestrated/branched stent-grafts after previous open or endovascular aortic surgery within the period March 2002-November 2013 was analyzed. Evaluated outcomes included initial technical success, operative mortality and morbidity and late procedure-related events with regard to survival, target vessel patency, and re-intervention. RESULTS: A total of 122 patients (110 male, 12 female; mean age mean age 70±9.5 years) were treated. Median time interval from previous aortic surgery to current fenestrated/branched stent-grafting was 80 months (range 3-261 months). Seventy-seven (63.1%) patients had previous open infrarenal aortic surgery, 33 (27%) had previous endovascular abdominal aortic aneurysm repair (EVAR), nine (7.4%) had previous open thoracic aortic surgery, and three (2.5%) had previous endovascular thoracic aortic repair (TEVAR). Indication for current treatment was a JAA in 65 (53.3%) patients and a TAAA in 57 (46.7%) patients. Technical success was achieved in 115 (94.3%) patients. Seven patients were considered as technical failure (open conversion; N.=1, target vessel loss; N.=6). Operative target vessel perfusion success rate with endovascular means was 98.5% (391/397). Intraoperative technical difficulties due to pre-existing stent-graft/surgical graft were encountered in 28 (23%) patients (access, N.=12; target vessel catheterisation, N.=16). Thirty-day operative mortality was 4.1% (5/122), with zero mortality in 65 JAA, and 8.8% (5/57) in TAAA, respectively. Cause of death was multiple organ failure (N.=3), acute gastrointestinal bleeding (N.=1), and subdural hematoma (N.=1). Major complications occurred in 20 (16.4%) patients. Median hospital stay was 7 days (range 3-50 days), and mean ICU stay 1.5±3.2 days. Mean follow-up was 22.5±21 months. All-cause late mortality was encountered in 23 patients, including one aneurysm-related mortality. Estimated survival was 91.2±3%, 83.3±4.2% and 81.1±4.6% at one, two and three years, respectively. During follow-up, eight target vessels occluded. Estimated target vessel patency was 97.2±1.1%, and 96.3±1.2% at one and three years, respectively. Reintervention during follow-up was required in 13 (10.6%) cases accounting for an estimated freedom from reintervention of 91.6±3.1%, and 82.1±5.4% at one and three years, respectively. CONCLUSION: Fenestrated and branched stent-grafting represents a feasible option for the repair of JAA and TAAA after prior endovascular or open aortic surgery. Despite increased technical difficulties it is associated with high technical success rate and is advantageous in terms of mortality and morbidity compared to redo open aortic surgery.
Subject(s)
Aortic Aneurysm, Abdominal/surgery , Aortic Aneurysm, Thoracic/surgery , Blood Vessel Prosthesis Implantation/instrumentation , Blood Vessel Prosthesis , Endovascular Procedures/instrumentation , Stents , Aged , Aortic Aneurysm, Abdominal/mortality , Aortic Aneurysm, Abdominal/physiopathology , Aortic Aneurysm, Thoracic/mortality , Aortic Aneurysm, Thoracic/physiopathology , Blood Vessel Prosthesis Implantation/adverse effects , Blood Vessel Prosthesis Implantation/mortality , Endovascular Procedures/adverse effects , Endovascular Procedures/mortality , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Postoperative Complications/mortality , Postoperative Complications/surgery , Prosthesis Design , Reoperation , Risk Factors , Time Factors , Treatment Outcome , Vascular PatencyABSTRACT
Implant surgery has been changing in different ways following improvements of computer technologies. Since its beginning, according to the original procedures of Branemårk system implants, guide-lines in implants-supported prosthetic rehabilitation have been founding on the placement of fixtures in a fairly upright position, after maxillary sinus floor elevation; while in the case of interforaminal rehabilitation, an upright distal implant may need to be placed anterior to the mental foramina without nerve damage (although the consequence would have been bilateral cantilevers to provide good chewing capacity). Some authors have proposed engaging the molar/tuberosity area: Bahat and Venturelli demonstrated these areas reliable and predictable alternative to distal cantilever prostheses or sinus elevation procedures. In recent years, the immediate loading of tilted implants with a provisional restoration has been proposed for the treatment of the atrophic maxilla. Tilted posterior implants in either arches could avoid (cantilever length) and provide to a better load distribution. Further studies have showed excellent outcomes for both tilted and axial implants; indeed this protocol allows to use longer implants, improve bone anchorage and avoid bone grafting procedures. Malò at al., in a retrospective clinical study, showed important results using two posterior tilted implants and two anterior non-tilted ones in the so-called All-on-four technique (Nobel Biocare, Göteborg, Sweden). Instead of the great loss of bone (amount and quality) in long-term edentuly the clinically documented computer-guided implantology software is able, through posterior tilted implants, to improve load distribution. Many authors have reported reduced surgical invasion (sinus grafting surgery is needless), shorter treatment time, lower cost, natural aesthetic profiles and functional bite.
ABSTRACT
Environmental profiles of mineral nitrogen fertilizers were used to evaluate the environmental disturbances related to their use in cultivation systems in Europe. Since the production of mineral fertilizers requires a large amount of energy, the present study of bioenergy systems is relevant in order to achieve crop yields less dependent on fossil fuels and to reduce the environmental impact due to fertilization. In this study, the suitability of the LCA methodology to analyze the environmental impact of sunflower cultivation systems with different forms of mineral nitrogen fertilizers urea and ammonium nitrate was investigated. Effects on climate change were estimated by the use of Ecoinvent 2.2 database default value for soil N2O emission factor (1%) and local emission data (0.8%) of mineral nitrogen applied to soils. LCA analysis showed a higher impact on environmental categories (human health and ecosystem quality) for the system in which urea was used as a nitrogen source. Use of urea fertilizer showed a higher impact on resource consumption due to fossil fuel consumption. Use of mineral nitrogen fertilizers showed a higher environmental burden than other inputs required for sunflower cultivation systems under study. Urea and ammonium nitrate showed, respectively, a 7.8% and 4.9% reduced impact of N2O as greenhouse gas by using direct field data of soil N2O emission factor compared to the default soil emission factor of 2006 IPCC Guidelines. Use of ammonium nitrate as mineral nitrogen fertilizer in sunflower cultivation would have a lower impact on environmental categories considered. Further environmental analysis of available technologies for fertilizer production might be also evaluated in order to reduce the environmental impacts of each fertilizer.
Subject(s)
Agriculture/methods , Environmental Monitoring/methods , Fertilizers/analysis , Helianthus/growth & development , Nitrogen Compounds/metabolism , Conservation of Natural Resources , Europe , Nitrates/metabolism , Urea/metabolismABSTRACT
It has been suggested that for success with immediate loaded dental implants it is necessary that, prior to their placement, bone quality and quantity as well as the biomechanical environment in which the implants are to function be evaluated.However, conventional techniques currently used for immediate implant placement lack sufficient precision and are usually accomplished by opening flap procedures. Nowadays computer-guided flapless surgery for implant placement using stereolithographic templates is gaining popularity among clinicians and patients. The advantages of this surgical protocol are its minimally invasive nature, accuracy of implant placement, predictability, less post-surgical disconfort and reduced time required for definitive rehabilitation. The introduction of digital planning programs has made it possible to place dental implants in preplanned positions and being immediately functionally loaded by using prefabricated prostheses. The surgical guide is used, infact, to develop a master model and fabricate the provisional bridge that will be secured to the implants immediately after their placement using the guided surgery template. In this way patients are able to achieve, in the same day of the surgery, a comfortable fixed rehabilitation needing only minor occlusal adjustments. Job S. et al during the three-month period, have demonstrated that the average reduction of crestal bone height around the implants placed with flapless surgery (0.06 mm) is not statistically significant, while the average reduction of crestal bone height around the implants placed using flap surgery (0.4 mm) is statistically significant, concluding that the use of stereolithographic appliances in accordance with flapless surgery makes immediate placement of the implants more predictable. However, the documentation of this technique in partial rehabilitations is limited. PURPOSE of this paper is to report the benefit of sophisticated pre-operative diagnostic implant planning and a flapless surgical approach with immediate loading in the rehabilitation of partial edentulies.
ABSTRACT
The prevalence of the elderly population, as well as life expectancy, increased in the final decades of the 20th century, as described in the World Health Organization 2004 Annual Report. The edentulous condition therefore has a negative impact on the oral health-related quality of life. Patients wearing complete dentures for many years infact, and especially in the mandible, are often unsatisfied because of the instability of the prosthesis during speaking and eating. To date dental implant treatment is well documented as a predictable treatment for partial or complete edentulism. On the other hand the rehabilitation of atrophied edentulous arches with endosseous implants (> 10 mm) in the posterior regions is often associated with anatomic problems such as bone resorption, poor bone quality, mandibular canal, and the presence of maxillary sinuses. Different procedures have been proposed to overcome these anatomic limitations. The use of tilted implants parallel to the anterior wall of the maxillary sinus or the mental foramen/inferior alveolar nerve has been proposed as a conservative solution for the treatment of the atrophic edentulous maxilla. Aim of this study was to describe, through a detailed literature review, the clinical and biomechanical rationale for tilting implants and to evaluate the long-term prognosis of immediately loaded full fixed prostheses for the treatment of edentulous patients (#35) with extreme bone atrophy rehabilited with both axial (#70) and tilted (#70) implants from 2008 to 2010. The results of the present study would suggest that this new surgical technique may reduce patient morbidity and extend the indications for immediate loading full fixed rehabilitations. This improves the predictability of treatment goal, allows for a better risk management, and provides more individual information for the patient. These are the most important aspects of this technology, which may contribute to establish higher-quality standards in implantology.
ABSTRACT
PURPOSE: A novel technique for transcrestal guided sinus lift elevation (TGSL), is described underlining the step by step surgical protocol. MATERIALS AND METHODS: TGSL modified osteotome technique was planned by the NobelProcera(®) Software Planning Programm (Nobel Guide, Nobel Biocare AB) and performed by stereolitographic template. The depth of the planned osteotomy was determined precisely via cross-sectional images of the elevation site to facilitate puncture of the bony sinus floor without risk of perforation of the adherent sinus membrane. A customized drilling-osteotome protocol is used to raise the Schneiderian membrane to the final implant length. RESULTS: The sinus membrane is successfully elevated in all sites without any iatrogenic perforation. CONCLUSIONS: The TGSL modified osteotome technique may provide a new option for minimally invasive transcrestal sinus surgery and may represent a safe method to increase bone volume in the atrophic posterior maxilla. The results of the present study would suggest that this new surgical technique may reduce patient morbidity and extend the indications for transcrestal maxillary sinus floor elevation.
ABSTRACT
The severe atrophy of the jaws are a challenging therapeutic problem, since the increase in bone is necessary to allow the placement of a sufficient number of implants. Combining immediate functionalization with the concept of guided surgery they combine the advantages offered by the innovative surgical and prosthetic implant technique (All-on-Four(®)) with those of computer-assisted planning in cases of severe bone atrophy. The method used in this case report, combines these two concepts in a surgical and prosthetic protocol safe and effective for the immediate function of 4 implants to support a fixed prosthesis in completely edentulous subjects. The integration of technology with immediate function with the concept of computer-guided surgery for implant placement and rehabilitation of completely edentulous jaws is now a predictable treatment modality with implant survival comparable to the traditional protocols.