Floristic analysis of a high-speed railway embankment in a Mediterranean landscape

We analyzed the floristic composition of a 4.5 km-long segment of a high-speed railway in Lazio, central Italy, which travels on an artificial embankment through an intensively-farmed landscape. In total, 287 vascular plant species were recorded. The life-form distribution was found to be similar to that of the regional species pool, with high percentages of therophytes (38%) and phanerophytes (13%). In the chorological spectrum the Mediterranean floristic element prevailed (44%), while alien species were 8% of the flora. The phytosociological spectrum showed a high diversity of characteristic species from the class Stellarietea mediae or its subordinate syntaxa (26%), and in particular from the order Thero-Brometalia (Mediterranean, sub-nitrophilous annual communities). Species from forest syntaxa had a relatively high diversity (9%). These results suggest that the ecological filtering provided by the Mediterranean regional climate controlled species assemblage even in a completely artificial habitat, preventing floristic homogenization: the flora of the studied railway section is only partially »ruderalized«, while it keeps strong links with the regional (semi-) natural plant communities. However, in contrast to what is observed in central and north Europe, the railway sides studied in the present paper do not seem to represent a refugial habitat for rare species from grassland communities, mainly because in Italy semi-natural dry grasslands are still widely represented

Influence of bone density on implant stability parameters and implant success: a retrospective clinical study

<p>Abstract</p> <p>Background</p> <p>The aim of the present clinical study was to determine the local bone density in dental implant recipient sites using computerized tomography (CT) and to investigate the influence of local bone density on implant stability parameters and implant success.</p> <p>Methods</p> <p>A total of 300 implants were placed in 111 patients between 2003 and 2005. The bone density in each implant recipient site was determined using CT. Insertion torque and resonance frequency analysis were used as implant stability parameters. The peak insertion torque values were recorded with OsseoCare machine. The resonance frequency analysis measurements were performed with Osstell instrument immediately after implant placement, 6, and 12 months later.</p> <p>Results</p> <p>Of 300 implants placed, 20 were lost, meaning a survival rate of %. 93.3 after three years (average 3.7 ± 0.7 years). The mean bone density, insertion torque and RFA recordings of all 300 implants were 620 ± 251 HU, 36.1 ± 8 Ncm, and 65.7 ± 9 ISQ at implant placement respectively; which indicated statistically significant correlations between bone density and insertion torque values (p < 0.001), bone density and ISQ values (p < 0.001), and insertion torque and ISQ values (p < 0.001). The mean bone density, insertion torque and RFA values were 645 ± 240 HU, 37.2 ± 7 Ncm, and 67.1 ± 7 ISQ for 280 successful implants at implant placement, while corresponding values were 267 ± 47 HU, 21.8 ± 4 Ncm, and 46.5 ± 4 ISQ for 20 failed implants; which indicated statistically significant differences for each parameter (p < 0.001).</p> <p>Conclusion</p> <p>CT is a useful tool to determine the bone density in the implant recipient sites, and the local bone density has a prevailing influence on primary implant stability, which is an important determinant for implant success.</p

Bucco-lingual bone remodeling around implants placed into immediate extraction sockets: a case series

Abstract: Background: Implants placed immediately after tooth extraction have shown high percentages of clinical success. Few studies in the scientific literature have observed the horizontal bone remodeling in the buccal-lingual direction after immediate placement of implants. The aim of this study was to analyze bone healing and coronal bone remodeling around 15 implants placed immediately after tooth removal without the use of guided bone regeneration (GBR) techniques. Methods: Ten patients received a total of 15 implants placed immediately after removal of 15 single-rooted teeth. All implants were placed within the alveolar confines, limiting, in most cases, small peri-implant bone defects. After implant placement, the distance from the buccal to lingual bone plate was measured. No membranes or filling materials were used. Primary flap closure was performed in all cases. Results: At second-stage surgery, all peri-implant defects were completely filled and the distance from buccal to lingual bone was measured again. The pattern of bone healing around the neck of immediate implants showed an absence of peri-implant defects and a narrowing of bone crest width in a buccal-lingual direction. The mean distance between buccal bone and lingual bone at the time of implant placement was 10.5 mm (+/-1.52) and, at second-stage surgery, 6.8 mm (+/-1.33). Conclusions: The coronal bone remodeling around immediate implants showed a healing pattern with new bone apposition around the neck of the implants and, at the same time, bone resorption with horizontal width reduction of the bone ridge. The small peri-implant bone defects were completely healed without the use of GBR procedures. An absence of complications during the healing period was also observed, probably due to the absence of barrier membranes and grafting materials

Connective tissue grafts in postextraction implants with immediate restoration: a prospective controlled clinical study

Advances in biomaterial technology and clinical research have equipped clinicians with efficient tools to provide advanced treatment options. As a result, some of the original prerequisites for osseointegration have been redefined to satisfy patients' expectations of reduced treatment time, improved aesthetics, and increased comfort. Novel treatment concepts, such as immediate implant loading and early implant loading, have been proposed to reduce the overall treatment time and to allow delivery of the definitive prosthesis in the shortest time possible following implant placement. The purpose of this clinical study was to evaluate the aesthetic results obtained following the placement of transmucosal implants into fresh extraction sockets and immediate restoration with provisional crowns

Buccal Bone Augmentation Around Immediate Implants With And Without Flap Elevation: A Modified Approach

Abstract Purpose: The aim of this study was to compare the clinical success and bone healing of implants placed in fresh extraction sockets using a flapless procedure compared to those placed with flap elevation. Materials and Methods: Twenty teeth in 20 patients were selected for this study and were scheduled for tooth extraction and immediate implant placement. Ten implants were placed with flap elevation (control group), and 10 implants were placed without flap elevation (test group). All the sites selected showed a complete bone defect at the facial wall. All the implants included in this study were 2-stage implants placed at the level of palatal/lingual bone in augmented bone. Each surgical site was protected with a collagen membrane and, subsequently, a standardized radiograph was taken to evaluate the distance between the implant shoulder and the first bone-implant contact (DIB). Six months after placement, both control and test implants underwent a second-stage surgery and a clinical examination to determine the implant stability quotient, DIB, and the distance between implant shoulder and the crestal bone at the midbuccal aspect (DIC). Results: One implant failed in the test group. Only 1 implant (test group) showed bone growth over the implant neck at the re-entry procedure. Implant stability quotient (ISQ) and DIB did not show any significant differences between the control and test group; however, a higher DIC was found in the test sites compared to the control sites. Conclusion: Data from this study showed that immediate implants with and without a mucoperiosteal flap elevation can be successfully used even in the presence of bone defects requiring augmentation procedures. It was also noted that the bone regenerated reached a higher coronal level in the group with flap elevation than in the group without flap elevation

Vertical crestal bone changes around implants placed into fresh extraction sockets

Abstract: Background: The aim of this study was to analyze bone healing and vertical bone remodeling for implants placed immediately after tooth removal without guided bone regeneration techniques. Methods: Twenty patients received 20 implants immediately after the removal of 20 teeth. All implants were placed within the undamaged alveoli confines, and the cervical portion of each implant was positioned at coronal bone level. The distance from implant shoulder and bone crest was measured for each implant at four sites (mesial, buccal, distal, and palatal/lingual). No membranes or filling materials were used. Primary flap closure was performed in all clinical cases. Results: All peri-implant bone defects had healed completely 6 months after implant placement. The pattern of bone healing around the neck of the implants showed an absence of peri-implant defects. The vertical distance between the implant shoulder and bone crest ranged from 0 to 2 mm. Conclusions: The bone remodeling of implants placed in fresh extraction sockets showed a healing pattern with new bone apposition around the implant's neck and horizontal and vertical bone reabsorption. The vertical bone reabsorption, which has been observed at buccal sites, was not associated with any negative esthetic implications

Clinical Outcome Of Implants Placed Immediately After Implant Removal

Abstract: Background: The purpose of this study was to evaluate the clinical success of implants placed immediately after the explantation of failed implants due to fracture at 12 months. Methods: Nine immediate implants were placed in nine patients following explantation of nine fractured implants. Five experimental implants did not require any regenerative procedures; the remaining four immediate implants were grafted with deproteinized porcine bone particles and covered with bioabsorbable membranes. All implants were restored with flxed prostheses. The follow-up period was 12 months. Results: No residual bone defects were observed or probed around any implant at the second-stage surgery, and all implants were asymptomatic and stable. All the implants were successful after prosthetic rehabilitation showing no mobility, pain, suppuration, or absence of peri-implant radiolucency. The radiographic measurements showed no signiflcant bone loss pattern at the 12-month follow-up visit. Conclusion: The findings of this study suggested that implants placed immediately after implant explantation due to biomechanical fracture could be performed with results that are similar to results obtained with implants placed immediately after tooth extraction