Mario Veltri
University of Siena
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Publication
Featured researches published by Mario Veltri.
Journal of Endodontics | 2004
Mario Veltri; Aniello Mollo; Pier Paolo Pini; Luca Ghelli; Piero Balleri
This study analyzed the abilities of ProTaper and GT Rotary files to shape the curved canals of extracted mandibular molars. Twenty mesial canals with curvatures ranging from 23 to 54 degrees (Weine analysis) were radiographically selected from a group of 58 molars. The specimens, divided into two groups, were instrumented using the two systems according to the manufacturers guidelines. Using a radiographic platform and a contrast medium, reproducible preinstrumentation and postinstrumentation radiographs were taken. A computer analysis allowed magnification and superimposition of the images to measure the preparation asymmetry and the linear amount of dentin removal at five points along the canals and to detect canal aberrations. Instrument failures, working time, and working length changes were recorded. The dentin removal and the mean asymmetry showed no significant differences between the two systems. Neither aberrations nor significant changes in working length resulted, but two instruments separated in each group. Working time was shorter for ProTaper files (p < 0.05).
Clinical Implant Dentistry and Related Research | 2012
Piero Balleri; Mario Veltri; Niccolò Nuti; Marco Ferrari
BACKGROUND Membrane elevation in combination with implant placement without biomaterials is a rather new technique proposed for sinus lifting. PURPOSE This study assessed the clinical outcome of such technique during the first year of loading. MATERIAL AND METHODS Fifteen patients with a mean residual bone height of 6.2 mm were consecutively recruited for sinus lifting. After opening a replaceable bone window, the membrane was dissected from the sinus walls. A total of 28 implants were placed in the residual crest and they kept the membrane lifted upwards. After window repositioning, the flap was sutured. A 6-month healing period was allowed. Patients were re-examined after 12 months of loading. RESULTS All the implants survived at the end of the follow-up. The 5.5 mm mean bone reformation was significantly lower than the 8.2 mm mean membrane lift achieved after implant placement. Regeneration at the distal surface of the most posterior implants was significantly less than at other aspects. The height of membrane lift was not correlated with the amount of regenerated bone. CONCLUSIONS All of the 28 implants placed in combination with sinus membrane elevation were stable during the first year of loading. No extra costs for biomaterial or morbidity for bone harvesting were necessary.
Clinical Oral Implants Research | 2008
Mario Veltri; Marco Ferrari; Piero Balleri
OBJECTIVES This study aimed at assessing the clinical outcome of narrow diameter implants in the treatment of knife-edge edentulous maxillas of adequate bone height but inadequate width (class IV of Cawood and Howell). MATERIAL AND METHODS Twelve consecutive patients (eight women and four men, mean age 58 years) with class IV atrophic edentulous maxillas were included in the study. Seventy-three microthreaded TiO(2)-blasted implants were placed and the resonance frequency measured. All the implants had a diameter of 3.5 mm. After 6 months of submerged healing, fixed implant-supported prostheses were delivered to the patients and resonance frequency and radiographic examinations performed. After the first year of loading, the implant outcome was again evaluated clinically, radiographically and with resonance frequency analysis. RESULTS All the implants were followed up to 1 year of loading and their survival rate was 100%. Bone loss after 1 year of loading was (mean+/-SD) 0.30+/-0.13 mm. Stability values were (mean+/-SD) 63+/-5.8 ISQ at placement, 60+/-4.7 ISQ at the abutment connection and 61+/-5 ISQ after 1 year of loading. A significant difference resulted between placement and abutment connection values (P=0.03). CONCLUSIONS According to the present study, narrow implants may be used to restore edentulous maxillas with atrophies of class IV of Cawood and Howell. When planning the treatment of edentulous maxillas with such a resorption pattern, this possibility has to be considered as an alternative to more demanding grafting techniques.
Clinical Oral Implants Research | 2011
Davide Apicella; Mario Veltri; Piero Balleri; Antonio Apicella; Marco Ferrari
OBJECTIVES The aim of the present study was to evaluate differences in the ultimate fracture resistance of titanium and zirconia abutments. MATERIAL AND METHODS Twenty titanium fixtures were embedded in 20 resin mandible section simulators to mimic osseointegrated implants in the premolar area. The embedded implants were then randomly divided into two groups. Afterwards, specimens in group A (n=10) were connected to titanium abutments (TiDesign™ 3.5/4.0, 5.5, 1.5 mm), while specimens in group B (n=10) were connected to zirconia abutments (ZirDesign ™ 3.5/4.0, 5.5, 1.5 mm). Both groups were loaded to failure in a dynamometric testing machine. Fractured samples were then analyzed by scanning electron microscopy (SEM). RESULTS Group A showed a significantly higher fracture strength than that observed in group B. Group A failures were observed at the screw that connects the abutment with the implant while the abutment connection hexagons were plastically bent by the applied load. Group B failures were a result of abutment fractures. SEM analysis showed that in group A the screw failure was driven by crack nucleation, coalescence and propagation, while in group B, the SEM analysis of failed surfaces showed the conchoidal fracture profile characteristic of brittle materials. CONCLUSIONS The strength of both tested systems is adequate to resist physiologic chewing forces in the premolar area. Conversely, the titanium and zirconia failure modes evaluated here occurred at unphysiological loads. In addition, because the abutments were tested without crowns, the presented data have limited direct transfer to the clinical situation.
Clinical Oral Implants Research | 2012
Oscar González-Martín; Ernesto Lee; Mario Veltri
OBJECTIVES To evaluate, on the base of cone beam computed tomography (CBCT) fractal dimension, bone quality changes surrounding the apical portion of immediate implants placed under higher insertion torque utilizing an undersized drilling technique. MATERIALS AND METHODS Three patients were enrolled in this study. Single implants were placed into fresh extraction sockets in the anterior maxilla and provisionalized immediately. Adequate stability was ensured on all the implants by a 28.5% undersizing of the apical portion of the osteotomy. Bone quality at the most apical 1.15 mm peri-implant bone portion were measured by CBCT at placement and after 6 months. This analysis was carried out by evaluating the box counting fractal dimension of 15 consecutive CBCT slices related to the most apical part of each implant. RESULTS All the three implants were successful after an 18-month follow-up period. The mean fractal dimension at the implant apex exhibited a 3% increase 6 months following placement. CONCLUSIONS Within the limitations of an explorative study, an undersized drilling resulting in high insertion torque would seem to induce no adverse changes in radiographic bone quality after 6 months of follow-up. The most favorable entity of drilling undersizing and its effect on peri-implant bone remodeling, should be evaluated on a larger patient population.
American Journal of Orthodontics and Dentofacial Orthopedics | 2009
Mario Veltri; Beatrice Balleri; Cecilia Goracci; Roberto Giorgetti; Piero Balleri; Marco Ferrari
INTRODUCTION Several miniscrews are available for skeletal anchorage. They have different geometries with self-drilling or self-tapping features. The aim of this study was to evaluate the soft bone primary stability of 3 different orthodontic screws by using the resonance frequency analysis. METHODS Aarhus mini-implant (Aarhus Mini-implant, Charlottenlund, Denmark) (A), Mini Spider Screws (HDC, Sarcedo, Italy) (S), and Micerium Anchorage System (Micerium, Avegno, Italy) (MAS) were investigated. To be compatible with the device used for resonance frequency analysis, the screws were modified (an abutment [Astra Tech, Mölndal, Sweden] was soldered on top). Four screws per system were tested. Each screw was placed in 5 excised rabbit femoral condyles, providing experimental models of soft bone. Placement was drill-free for the A screw, whereas the MAS and S screws required a pilot hole through the cortical layer. After each placement procedure, resonance frequency was assessed as a parameter of primary stability. Differences among the systems were analyzed by using analysis of variance for repeated measures, with the level of significance at P < 0.05. RESULTS The recorded resonance frequencies (in Hz) were (mean +/- SD): MAS, 6236.1 +/- 192.1; S, 6270.1 +/- 99.7; and A, 6193.1 +/- 142.4. Differences among the groups were not statistically significant (P > 0.05). CONCLUSIONS The resonance frequency analysis is applicable to comparatively assess the primary stability of orthodontic miniscrews. The 3 systems had similar outcomes in an experimental model of soft bone.
Clinical Implant Dentistry and Related Research | 2010
Piero Balleri; Marco Ferrari; Mario Veltri
BACKGROUND Implant treatment in the partially edentulous maxilla is often challenging because of minimum bone volumes in distal direction. PURPOSE The aim of this study was to evaluate, after 1 year of loading, the outcome of three-unit fixed partial dentures supported by two implants in the retrocanine triangle. MATERIALS AND METHODS Twenty patients with atrophic posterior maxillae participated in the study. A total of 40 implants were placed in residual bone anterior to the sinus wall and posterior to the canine. Implant angulations and lengths were chosen to match as much as possible boundaries of the available bone. After a 6-month healing period, three-unit, screw-retained, fixed partial dentures were delivered. The patients were clinically and radiographically reexamined after 1 year of loading. RESULTS All the implants survived at the end of the follow-up. No differences in bone level changes resulted between axial and tilted implants. No biological or mechanical complications were recorded. CONCLUSIONS Within the limitations of this short-term study on relatively few patients, a positive outcome was seen for three-unit fixed partial dentures supported by two implants. Retrocanine placement of implants with carefully planned lengths and angulations might be an alternative to grafting procedures for restoration of atrophic posterior maxillae.
International Journal of Oral and Maxillofacial Surgery | 2008
E. Sani; Mario Veltri; Maria Crysanti Cagidiaco; Piero Balleri; Marco Ferrari
Owing to the increasing use of dental implants to restore edentulous conditions, clinicians often face situations where available bone volumes are reduced and need to be augmented before implant placement. This is common in the posterior maxilla, where the presence of the maxillary sinus combined with severe atrophy of the bone crest, owing to long-standing edentulism or pathological conditions, might preclude implant placement. Techniques to augment the sinus floor in combination with several grafting materials are commonly used to restore adequate volumes for implantation. Recent studies have described bone reformation and integration of oxidized implants by simple elevation of the sinus membrane without any grafting material. The aim of this case report is to document the application of the sinus membrane elevation technique in combination with the placement of 3 blasted microthreaded implants in a patient who was clinically and radiographically followed up for 3 years. During the follow-up period, the blasted implants were all stable and intraoral radiographs showed that the bone reformed in contact with the implants and remained stable.
Journal of Biomechanics | 2014
Roberto De Santis; Antonio Gloria; Teresa Russo; Ugo D’Amora; Angelo Varriale; Mario Veltri; Piero Balleri; Francesco Mollica; Francesco Riccitiello; Luigi Ambrosio
This study aimed at investigating the effects of titanium implants and different configurations of full-arch prostheses on the biomechanics of edentulous mandibles. Reverse engineered, composite, anisotropic, edentulous mandibles made of a poly(methylmethacrylate) core and a glass fibre reinforced outer shell were rapid prototyped and instrumented with strain gauges. Brånemark implants RP platforms in conjunction with titanium Procera one-piece or two-piece bridges were used to simulate oral rehabilitations. A lateral load through the gonion regions was used to test the biomechanical effects of the rehabilitations. In addition, strains due to misfit of the one-piece titanium bridge were compared to those produced by one-piece cast gold bridges. Milled titanium bridges had a better fit than cast gold bridges. The stress distribution in mandibular bone rehabilitated with a one-piece bridge was more perturbed than that observed with a two-piece bridge. In particular the former induced a stress concentration and stress shielding in the molar and symphysis regions, while for the latter design these stresses were strongly reduced. In conclusion, prosthetic frameworks changed the biomechanics of the mandible as a result of both their design and manufacturing technology.
International Journal of Periodontics & Restorative Dentistry | 2014
Oscar González-Martín; Mario Veltri; Osvaldo Moraguez; Urs C. Belser
The aim of this study was to describe a technique for the assessment of soft tissue volumetric and profilometric changes. The technique has been applied at the alveolar contour of mild to moderate horizontal ridge defects after soft tissue augmentation at pontic sites. A quantitative three-dimensional (3D) analysis based on laser scanning was used for the measurement of volume gain and horizontal changes of alveolar profile 5 months after a subepithelial connective tissue graft using a pouch approach in five patients. All the surgical sites healed uneventfully. A mean soft tissue volume increase of 35.9 mm3 was measured 5 months after the grafting procedure. The linear measurements showed that, in the area where the augmentation was performed, the distance between the preoperative vestibular profile and the postoperative one ranged from 0.16 to 2 mm. The described quantitative measurements based on 3D laser scanning appear to be an effective method for assessment of soft tissue changes in future studies. Additionally, within the limitation of a small sample size, the present data suggest that the investigated surgical technique can be considered when corrections of mild to moderate alveolar horizontal ridge atrophies at maxillary lateral incisor edentulous gaps are necessary.