501 research outputs found
One-Month Postoperative Reentry for Maxillary Sinus Floor Augmentation After a Large Sinus Membrane Perforation: A Retrospective Clinical and Radiographic Analysis
No full textThe aim of this retrospective analysis was to evaluate the clinical and radiographic results of a shortened protocol (using a lateral approach) for early surgical reentry, following a large sinus membrane perforation that occurred during maxillary sinus augmentation (lateral approach), for the rehabilitation of patients with an atrophic posterior maxilla. Between May 2015 and October 2020, seven patients underwent reentry surgery using a lateral approach protocol 1 month after a large sinus membrane perforation during maxillary sinus floor augmentation with lateral approach surgery. All patients presented a residual under-sinus bone height < 3 mm in the posterior maxilla. The sinus membrane was elevated during the reentry surgery, without any difficulty for any patient, using manual blunt elevators or piezoelectric devices, and the sinus floor height was augmented with bone substitute particles. No further perforations were made, and no complications were recorded during the follow-up period from 18 months to 6 years. The 1-month waiting period after the initial sinus surgery allows easy sinus membrane elevation and a lack of complications. This timing could be a feasible option for surgical reentry after a large sinus membrane perforation occurs. Int J Periodontics Restorative Dent 2023;43:241-246. doi: 10.11607/prd.6463
Sling Suture Technique Used to Stabilize the Collagen Membrane on the Lateral Bone Window During Maxillary Sinus Floor Augmentation With a Lateral Approach: A Retrospective Case Series
No full textPurpose: Maxillary sinus floor augmentation is a safe and predictable technique used to increase bone volume under sinus cavity for implant placement in atrophic posterior maxilla before implant placement. Despite conflicting results concerning the new bone formation rates with or without a barrier membrane, the benefits of using a collagen membrane to cover the lateral bone window has been demonstrated, in order to prevent bone substitute particles dislodgement that may occur from the sinus cavity through the sinus antrostomy towards the oral mucosa, and to significantly reduce the postoperative swelling and pain reactions. The purpose of this case series is to present a sling suture technique used to stabilize the collagen membrane against the lateral bone window so as to improve the bone substitute stability inside the sinus cavity. Materials and methods: Maxillary sinus floor augmentation with lateral approach using sling suture technique to maintain the collagen membrane against the lateral bone window was performed in 17 patients (8 women/ 9 men, mean age: 58.2 years). Postoperative cone-beam computed tomography (CBCT) images up to 6-month follow-up were performed to control the bone graft stability at the level of the lateral antrostomy. The clinical postoperative pain and swelling were assessed through a Visual Analogue Scale (VAS) questionnaire from level 1 (low), level 5 (acceptable), to level 10 (high) at one week postoperative. Results: No bone substitute displacement was observed for all clinical cases on the CBCT images at 6-month postoperative. The pain and swelling level observed at one-week post operative were significantly low (respectively 1.6±1.0/2.1± 0.9). Conclusions: Within the limits of this case series, the use of sling suture technique to maintain the barrier membrane at the level of the lateral bone window in case of maxillary sinus floor augmentation with lateral approach surgery revealed to be a predictable protocol to prevent bone substitute displacement outside the sinus cavity
Does the Etiology of Pulp Necrosis affect Regenerative Endodontic Treatment Outcomes? A Systematic Review and Meta-Analyses
No full textObjective: To evaluate if there is a connection between the causes of pulp necrosis (eg, caries, trauma, dental anomaly) and the success of regenerative endodontic treatment. Methods: Electronic databases (PubMed, Scopus, Web of Science, Cochrane Central Register of Controlled Trials, Embase) were searched for studies on regenerative endodontic treatment, which used both clinical and radiographic evaluation of root maturation after at least 6 months of follow-up. The search terms “necrotic pulp”, “regenerative endodontic treatment”, “revascularization”, and “revitalization” were combined using Boolean operators. The main journals on endodontics and dental traumatology were additionally hand-searched. Studies were included if they specified the causes of pulp necrosis. The primary question under review was, “Does the cause of pulp necrosis affect the outcome of regenerative endodontic treatment?” Other factors such as tooth type, intracanal medicament, irrigation protocol, use of a collagen matrix, and the type of scaffold were evaluated for possible relation with the outcome. The risk-of-bias assessment for randomized and nonrandomized studies was performed separately, using a modified Cochrane Collaboration's tool and risk of bias in non-randomized studies of interventions-I tool, respectively. Meta-analysis was performed, when possible, between studies comparing treatment outcomes of teeth whose pulp necrosis had different etiology. The search strategy yielded 1197 items. After screening, 18 studies reporting 445 regenerative endodontic treatment cases were included. Results: The overall success rate for 274 teeth with trauma etiology was 94.8%, for 95 teeth with dens evaginatus etiology was 93.1%, and for 24 teeth with caries etiology was 96%. No significant difference was found between the results of regenerative endodontic treatment among teeth with trauma, dens evaginatus, and caries etiology (P = .055). Meta-analysis of studies comparing teeth with caries vs dens evaginatus and those with trauma vs caries confirmed that there was no evidence for difference in outcomes. Conclusion: Further randomized studies specifically testing such hypothesis are needed to confirm the preliminary results of this review
Endodontic therapy using magnification devices. A systematic review
No full textOBJECTIVES:
The purpose of this systematic review was to investigate if the use of magnification devices in endodontics is associated with the improvement of clinical and radiographic outcomes.
DATA:
The treatment success as determined by clinical and radiographic evaluation after 1-year follow-up was the main outcome. The main search terms used alone or in combination were: endodontic treatment, endodontic therapy, endodontic surgery, apicoectomy, periapical surgery, microscope, endoscope, loupes, magnification devices.
SOURCES:
The authors searched MEDLINE, Embase, Cochrane Oral Health Specialized Register, Cochrane Central Register of Controlled Trials for articles published up to September 2009 plus hand-searching of relevant journals and reference list of pertinent reviews and included studies.
STUDY SELECTION:
Prospective clinical trials comparing endodontic therapy performed with or without using magnification devices, as well as trials comparing two or more magnification devices for endodontic therapy were considered.
CONCLUSIONS:
Three prospective studies were included, all dealing with endodontic surgery. No significant difference in outcomes was found among patients treated using magnifying loupes, surgical microscope or endoscope. Similarly, no difference was found with or without using the endoscope. No comparative study on magnification devices was found regarding orthograde endodontic treatment. The type of magnification device per se can only minimally affect the treatment outcome. Well-designed randomized trials should be performed to determine the true difference in treatment outcomes when using a magnification device in both orthograde and surgical endodontic treatment, if any exist
Endoscopic endodontic microsurgery: 2-year evaluation of healing and functionality
No full textThis prospective clinical study aimed to evaluate the benefits of the endoscope as an aid to root-end management, and to assess the treatment outcome during 2 years following surgery. Forty-three endodontic surgical procedures in 30 patients were performed with the aid of an endoscope and followed for a period of 2 years. Radiographic criteria and clinical evaluation were used to assess the outcome. All cases were evaluated in terms of healing and functionality. 91.1% and 90.7% of the teeth evaluated after 1 and 2 years, respectively, were classified as successful. We found no statistically significant differences for both healing and functionality between the 1- and 2-year evaluations. No difference related to tooth type or tooth location was found at the 2-year follow-up. Fisher's exact test was used to statistically assess the difference between successful and unsuccessful cases for each of the variables considered. The endoscope can be an aid for endodontic surgical procedures in terms of both periapical healing and functionality up to 2 years follow-up
Postextraction osteotome sinus floor elevation technique using plasma-rich growth factors
No full textPURPOSE: To evaluate a modified osteotome sinus floor elevation technique with immediate postextraction implant placement and the adjunct of a platelet-derived fibrin plug for the rehabilitation of maxillary premolar sites.
MATERIAL AND METHODS:
Fifteen patients with nonrestorable fractured endodontically treated maxillary premolars were consecutively enrolled in the study. After extraction, the membrane was gradually elevated using osteotomes, with the interposition of a fibrin clot. Subsequently, an implant embedded with plasma very rich in growth factors was inserted.
RESULTS:
No implant failed after a mean follow-up of 35 months. The average membrane lift was 2.9 ± 0.8 mm. After 1 year of loading, marginal bone loss averaged 0.36 ± 0.19 mm. No postoperative symptoms were reported. All patients reported full satisfaction for mastication function, phonetics, and aesthetics.
CONCLUSIONS:
The present technique represents a viable option for the rehabilitation of fresh postextraction maxillary premolar sockets
Autologous platelet concentrates for treatment and prevention of MRONJ. A systematic review of the literature
No full textBACKGROUND: Medication related osteonecrosis of the jaw (MRONJ) is a drug-related adverse event consisting of progressive bone destruction in the maxillofacial region of patients under current or previous treatment with an antiresorptive agent, the most popular being bisphosphonates. Autologous platelet concentrates (APC) demonstrated to enhance bone and soft tissue healing in oral surgery procedures.
This systematic review aimed to evaluate if APC may improve treatment and prevention of MRONJ in patients under antiresorptive therapy.
Methods: An electronic search was performed on the following databases: MEDLINE, Scopus, Web of Science and Cochrane. The following search terms were used: “bisphosphonate”, “denosumab”, "antiresorptive agents”, “antiresorptive therapy”, “BRO NJ”, “MRONJ”, “osteoporosis”, “osteonecrosis”,
“maxilla”, “mandible”, “platelet-rich plasma”, “platelet concentrates”, “platelet growth factors”, “platelet-rich fibrin”, “PRP”, “PRGF”, “PRF”, “Platelet-Derived Growth Factor”, “PDGF”, “CGF”, “oral surgery”, “extraction socket”, “tooth extraction”. The limit “humans” was applied. For being included, studies had to report clinical results of oral surgery procedures in patients under antiresorptive therapy, in which APC agents were used for improving the clinical outcome. Both articles reporting on the treatment of an existing condition of MRONJ and those reporting on the incidence/onset of MRONJ in patients undergoing
oral surgery procedures were considered. Restrictions were not placed regarding the language and the year of publication. Both prospective and retrospective studies with at least 5 patients and 3 months follow-up were included. Case studies/reports were not included. The studies had to provide details on the type and dosage of antiresorptive drug taken, and the indication for antiresorptive therapy. Publications not dealing with original clinical cases (e.g. reviews, technical reports, expert opinions) were also excluded. The main variables extracted from each included study were: study design, study setting (university, hospital, private practice), sample size, patients gender and age, proportion of smokers, type, dosage and administration route of antiresorptive drug taken, reason for antiresorptive treatment, dosage, duration
of treatment at surgery, type of APC used, jaw (maxilla or mandible), any outcome variable used to evaluate treatment success, follow-up duration, complications, adverse events, postsurgical onset/recurrence of MRONJ. The MRONJ staging definition proposed by the AAOMS in 2014 was used as a reference.
Results: Thirteen studies were included, reporting on 648 patients undergoing oral surgery. The main surgical procedures were tooth extraction, dental implant placement, resection of necrotic tissue. APCs used were platelet-rich plasma, plasma rich in growth factors, platelet-rich fibrin. Post-surgery
follow-up ranged from 3 to 94 months. The adjunct of APC in MRONJ treatment significantly reduced osteonecrosis recurrence with respect to control. APC was associated with a lower BRONJ incidence after tooth extraction, though not significant. Heterogeneity was found regarding medication type, clinical
indication, triggering factors, study design, follow-up duration, type of APC, outcomes adopted to evaluate treatment success.
Conclusions: Though the results of this review must be cautiously interpreted, due to the low evidence level of the studies included, and the limited sample sizes, they are suggestive of possible benefits of APC when associated with surgical procedures for treatment or prevention of BRONJ. To confirm such indication, prospective comparative studies with a large sample size are urgently needed
Sub-barrier fusion for 24,26Mg + 12C. New techniques of gamma-particle and heavy ion-particle coincidences for 30Si + 12C
No full textIl lavoro di tesi consiste nello studio della dinamica di fusione di sistemi con Q-valore positivo ad energie molto al disotto della barriera Coulombiana. Lo studio di sistemi con Q-valore positivo è di particolare interesse per l'astrofisica, ma stabilire la presenza dell'effetto di hindrance per questi sistemi richiede misure impegnative. Per questo motivo, lo studio di sistemi leggermente più pesanti è molto importante. Il sistema 24Mg+12C è di particolare interesse poichè presenta due caratteristiche particolari. La prima è il valore molto alto della sezione d'urto alla soglia dell'hindrance rispetto ad altri sistemi simili, la seconda sta nel fatto che ad energie molto basse i dati sperimentali sono riprodotti da un semplice modello unidimensionale basato sulla penetrazione della barriera. La funzione di eccitazione del 24Mg+12C è stata riprodotta usando due modelli diversi, il primo è una formula empirica nello spirito del modello adiabatico. La seconda è una parametrizzazione dell'hindrance usato per riprodurre la funzione di eccitazione di molti sistemi con Q-valore positivo. Per capire meglio la ragione dietro l'alto valore della sezione d'urto alla soglia dell'hindrance, è stato misurato il sistema 26Mg+12C. In questo esperimento la sezione d'urto di fusione è stata ottenuta rivelando direttamente i residui di evaporazione (ER) con il set-up PISOLO che consiste in un deflettore elettrostatico usato per separare gli ER dal fascio trasmesso, due MCP che misura il tempo di volo, una camera di ionizzazione che misura l'energia persa e un rivelatore al silicio che misura l'energia residua. Combinando le informazioni fornite da PISOLO è possibile estrarre la sezione d'urto di fusione fino a 6 μb insieme alla derivata logaritmica e al fattore astrofisico S. Confrontando i due sistemi si può notare che nel caso 26Mg+12C il massimo del fattore S è meno evidente e il valore della sezione d'urto alla soglia dell'hindrance è più piccola rispetto al caso del 24Mg+12C. La ragione potrebbe essere la struttura α-like del 24Mg non presente per il 26Mg. Si può anche notare che la derivata logaritmica di entrambi i sistemi presenta delle oscillazioni che potrebbero essere collegate alla bassa densità dei livelli del nucleo composto. Per discriminare fra i due modelli usati per riprodurre la sezione d'urto sperimentale del 24Mg+12C è necessario eseguire misure precise ad energie molto al disotto della barriera. Però, PISOLO non può essere usato per misurare sezioni d'urto inferiore a pochi μb, per questo, sono stati testati due metodi alternativi per misurare funzioni di eccitazione nell'ordine dei nanobarn. Il primo è un miglioramento del set-up PISOLO: due rivelatori al silicio sono stati installati nella camera di reazione per rivelare le particelle cariche evaporate dal nucleo composto in coincidenza con gli ER rivelati da PISOLO. Questa tecnica è stata testata con il sistema 30Si+12C misurando le energie 47, 40 e 37 MeV. I risultati ottenuti mostrano una forte riduzione del fondo che può permettere di misurare sezioni d'urto di fusione inferiori a 1μb con PISOLO, al costo di una efficienza minore del set-up. Il secondo metodo si basa sulle coincidenze fra le particelle evaporate dal nucleo composto e i raggi-γ emessi dagli ER. Per questo esperimento sono stati usati lo spettrometro-γ AGATA e l'array di rivelatori al silicio a due stadi EUCLIDES per studiare l'esperimento 30Si+12C misurando le energie di 47 e 40 MeV. L'analisi è stata fatta selezionando gli eventi riconosciuti come protoni e particelle α negli spettri E-∆E per poi studiare gli spettri-γ in coincidenza. Questo permette di identificare le transizioni che vanno direttamente al fondamentale in modo da estrarre la sezione d'urto di fusione. Il testo ha prodotto buoni risultati e un esperimento basato sulle coincidenze γ-particelle cariche è stato fatto per misurare la sezione d'urto del sistema 28Si+12C usando AGATA e due DSSD.The thesis work focuses on the study of the fusion dynamics of systems with positive Q-value at energies far below the Coulomb barrier. The study of systems with positive Q-value is of particular interest for astrophysics, but establishing the presence of the hindrance effect for these systems requires challenging measurements. For this reason, the study of slightly heavier systems is very important. The system 24Mg + 12C is of particular interest since it presents two peculiar features. The first one is the very high value of the cross section at the hindrance threshold compared with other similar systems, the second one is that the experimental data at very low energies are well reproduced by a simple one-dimensional barrier penetration calculation. The excitation function of 24Mg + 12C has been reproduced with two different models, the first one is an empirical formula in the spirit of the adiabatic model. The second one is a hindrance parametrization used to reproduce the excitation function of several systems with positive Q-values. To better understand the reason behind the high value of the cross section at the hindrance threshold, the system 26Mg + 12C has been measured. The fusion cross section in this experiment has been obtained detecting the evaporation residue (ER) by the set-up PISOLO consisting of an electrostatic deflector to separate the ER from the transmitted beam, two MCP to measure the time of flight, an ionization chamber to measure the energy loss and a silicon detector giving the residual energy. Combining the information provided by PISOLO it has been possible to extract the fusion cross section down to about 6 μb together with the logarithmic slope and the astrophysical S factor. Comparing the two systems one can notice that for the 26Mg + 12C case the maximum for the astrophysical S factor is narrower and the value of the cross section at the hindrance threshold is smaller compared with what has been obtained for the 24Mg + 12C case. The reason may be the α-like structure of the 24Mg not owned by the 26 Mg. One can also notice that the logarithmic derivative presents some oscillations for both systems that could be related to the low level density of the compound nucleus. To discriminate between the two models used reproducing the experimental cross section of 24Mg + 12C at deep sub-barrier energies it is necessary to perform precise measurements at lower energies. However, PISOLO can not be used to measure cross section below a few μb, therefore, two alternative methods to measure the excitation function in the nanobarns range have been tested. The first one is an upgrade of the PISOLO set-up: two two-stage silicon detectors have been installed inside the reaction chamber to detect the light charged particles evaporated by the compound nucleus in coincidence with the ER detected by PISOLO. This technique has been tested for the system 30Si + 12C measuring three energies 47, 40 and 37 MeV. The results obtained show a large reduction of the background that could allow the measurement of fusion cross section below 1μb with PISOLO, at the cost of a lower efficiency of the set-up. The second method is based on the coincidences between the charged particles evaporated by the compound nucleus and the γ-rays emitted by the ER. To perform this measurement the γ-spectrometer AGATA and the array of two-stage silicon detectors EUCLIDES have been used to study the system 30Si + 12C at the energies of 47 and 40 MeV. The analysis has been performed by selecting the protons and α particles events in the E-∆E spectra and studying the γ-spectra in coincidence. This allows to identify the transitions of the ER that go directly to the ground state so to extract the fusion cross section. The test has been successful and an experiment based on the γ-charged particles coincidence technique has been performed to measure the fusion cross section of the system 28Si + 12C using AGATA and two DSSD detectors
Subatmospheric pressure in the rabbits pleural lymphatics
No full text1. Hydraulic pressure in intercostal and diaphragmatic lymphatic vessels was measured through the micropuncture technique in 23 anaesthetised paralysed rabbits. Pleural lymphatic vessels with diameters ranging from 55 to 950 microm were observed under stereomicroscope view about 3-4 h after intrapleural injection of 20 % fluorescent dextrans. 2. Lymphatic pressure oscillated from a minimum (Pmin) to a maximum (Pmax) value, reflecting oscillations in phase with cardiac activity (cardiogenic oscillations) and lymphatic myogenic activity. With intact pleural space, Pmin in submesothelial diaphragmatic lymphatic vessels of the lateral apposition zone was -9.1 +/- 4.2 mmHg, more subatmospheric than the simultaneously recorded pleural liquid pressure amounting to -3.9 +/- 1.2 mmHg. In extrapleural intercostal lymphatic vessels Pmin averaged -1.3 +/- 2. 7 mmHg. 3. Cardiogenic pressure oscillations (Pmax - Pmin), were observed in all recordings; their mean amplitude was about 5 mmHg and was not dependent upon frequency of cardiac contraction, nor lymphatic vessel diameter, nor the Pmin value. 4. Intrinsic contractions of lymphatic vessel walls caused spontaneous pressure waves of about 7 mmHg in amplitude at a rate of 8 cycles min-1. 5. These results demonstrated the ability of pleural lymphatic vessels to generate pressure oscillations driving fluid from the subatmospheric pleural space into the lymphatic network
Isola dei Granai, Danzica
No full textPresentazione del progetto per la trasformazione dell'Isola dei granai in centro città, redatto da G. Polesello con i suoi allievi (R. Fein, M. El Daccache, A. Dal Fabbro, M. Iori, S. Maffioletti, M. Montuori, P. Valle) in occasione del Seminario internazionale organizzato dall'Ordine degli Architetti della Polonia, Danzica 1989
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