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How to limit treaty-shopping
Investors’ treaty-shopping continues to represent a source of unpredictability regarding issues of jurisdiction and/or admissibility before arbitral tribunals. States should consider effectively solving this through apposite treaty provisions. Such clauses would include definitions of corporate investors requiring substantial business activities in the home State, denial-of-benefits and carve-out of dispute-settlement issues from MFN treatment
A Dual Hybrid Virtual Element Method for Plane Elasticity Problems
A dual hybrid Virtual Element scheme for plane linear elastic problems is
presented and analysed. In particular, stability and convergence results have
been established. The method, which is first order convergent, has been
numerically tested on two benchmarks with closed form solution, and on a
typical microelectromechanical system. The numerical outcomes have proved that
the dual hybrid scheme represents a valid alternative to the more classical
low-order displacement-based Virtual Element Method
Extraction socket preservation using porcine-derived collagen membrane alone or associated with porcine-derived bone. Clinical results of randomized controlled study
The aim of present randomized controlled clinical trial was to clinically evaluate hard tissue changes after extraction socket preservation procedures compared to natural spontaneous healing
Implant survival and success rates in patients with risk factors: results from a long-term retrospective study with a 10 to 18 years follow-up
OBJECTIVE:
Risk factors for implant therapy are represented by all general and local conditions that through various mechanisms can increase either short-term and long-term failure risk. The aim of this study is to assess the implant survival and implant success rates with single and multiple risk factors.
PATIENTS AND METHODS:
To address the research purpose, a retrospective cohort study was designed and implemented, including a sample of 225 patients with a total of 871 implants placed. The following risk factors were considered: smoking, bruxism, bone augmentation procedures and the presence of load risk (implants with crown/implant relation > 0.8; angulation > 25°; presence of cantilever). Follow-up ranged from 10 years to 18 years (average follow-up 13.6 years). Failures were subdivided into short-term failures, before the prosthetic phase, and long-term failures, after definitive prosthesis. The success criteria published by Albrektsson and Zarb were adopted. A Cox proportional hazard regression model was used to calculate hazard ratio, with a statistically significant p-value <0.05.
RESULTS:
Out of the 871 implants placed, 138 did not meet the success criteria, (success rate 84.16%), sixty (43.47%) were classified as "early failure" and seventy-eight as "late failure" (56.53%). A total of 70 dental implants were removed, with a survival rate of 91.96%.
CONCLUSIONS:
The presence of a single risk factor does not imply a marked increase of failure risk. Among the analyzed factors, the one that proved to be the most dangerous was bruxism, even when presented as the only risk factor. Bruxism with load risk proved to be the most dangerous association (success rate 69.23%) and could be included among the absolute contraindications for implant treatment
Effect of airborne particle abrasion on microtensile bond strength of total-etch adhesives to human dentin
Aim of this study was to investigate a specific airborne particle abrasion pretreatment on dentin and its effects on microtensile bond strengths of four commercial total-etch adhesives. Midcoronal occlusal dentin of extracted human molars was used. Teeth were randomly assigned to 4 groups according to the adhesive system used: OptiBond FL (FL), OptiBond Solo Plus (SO), Prime & Bond (PB), and Riva Bond LC (RB). Specimens from each group were further divided into two subgroups: control specimens were treated with adhesive procedures; abraded specimens were pretreated with airborne particle abrasion using 50 mu m Al2O3 before adhesion. After bonding procedures, composite crowns were incrementally built up. Specimens were sectioned perpendicular to adhesive interface to producemultiple beams, which were tested under tension until failure. Data were statistically analysed. Failure mode analysis was performed. Overall comparison showed significant increase in bond strength (p < 0.001) between abraded and no-abraded specimens, independently of brand. Intrabrand comparison showed statistical increase when abraded specimens were tested compared to no-abraded ones, with the exception of PB that did not show such difference. Distribution of failure mode was relatively uniform among all subgroups. Surface treatment by airborne particle abrasion with Al2O3 particles can increase the bond strength of total-etch adhesive
A randomized clinical trial about presence of pathogenic microflora and risk of peri-implantitis: comparison of two different types of implant-abutment connections
OBJECTIVE:
The aim of this in vivo study was to evaluate two different types of implant-abutment connections: screwed connection and cemented connection, analyzing peri-implant bacteria microflora as well as other clinical parameters.
PATIENTS AND METHODS:
Twenty implants were selected, inserted in 20 patients, 10 with a screwed implant-abutment connection (Group 1) and 10 with a cemented implant-abutment connection (Group 2). The peri-implant microflora was collected, after at least 360 days from the prosthetic rehabilitation, using paper points inserted in peri-implant sulcus for 30 s. Polymerase chain reaction (PCR) Real-time analyzed the presence of 9 bacteria periodontal-pathogens and Candida albicans.
RESULTS:
Our findings showed that bacteria colonized all Groups analyzed, the average bacterial count was 3.7 E +08 (±1.19) in Group 1, compared to 2.1 E +08 (±0.16) in Group 2; no statistically significant differences were observed (p>0.0.5). In Group 1, however, bacterial colonization of peri-implant sulci was over the pathogenic threshold for 5 bacteria, indicating a high-risk of peri-implantitis. Also in Group 2, results showed a microflora composed by all bacteria analyzed but, in this case, bacterial colonization of peri-implant sulci was over the pathogenic threshold for only 1 bacterium, indicating a lower risk of peri-implantitis. Moreover, clinical parameters (PPD > 3 mm and m SBI > 0) confirmed a greater risk of peri-implantitis in Group 1 compared to Group 2 (p<0.05).
CONCLUSIONS:
We concluded that, also after only 360 days, implants with screwed connection showed a higher risk of peri-implantitis that implants with cemented connection
Accuracy and precision of an intraoral scanner in complex prosthetic rehabilitations: an in vitro study
The main purpose of this study is to measure the accuracy and the precision of the intraoral
optical scanner CS3500® (Carestream Dental LLC, Atlanta, USA) in complex clinical situations as
full arch rehabilitations on impl
ants.
50 scans of the acrylic resin model were performed by using CS3500® (Carestream Dental
LLC, Atlanta, USA) scanner. Each scan was compared with the virtual model derived from scanning
with the laboratory scanner Dscan3® (Enhanced Geometry Soluti
on, Bologna, Italy) to measure a
possible misalignment.
The alignment error was found to be 79,6 (
±
12,87)
m. The measurement was taken at the
level of 2 distal scan
-
abutments. The scanner's precision ranges from 24 to 52
m , depending on
the dist
ance between scan
-
abutment.
CS3500® (Carestream Dental LLC, Atlanta, USA) intraoral scanner has detected a valid device
in the execution of complex rehabilitations on implants. His accuracy and precision values fall within
the range established in li
terature to define acceptable the prosthetic fitting on full arch implant
rehabilitation
Influence of the oral status on cardiovascular diseases in an older Italian population
Oral diseases have been adversely associated with cardiovascular diseases (CVD), which are also the most frequent
cause of death in older population. The aim of this study was to investigate the association among oral status indexes and
CVD in patients aged more than 65 years attending in the Oral department of a public hospital Policlinico Umberto 1 of
Rome. The study population consisted of 533 patients. Dental status was detected measuring the Decayed, Missing, and
Filled Teeth (DMFT) and Community Periodontal Index (CPI) indexes. The chi-square test with a 95% confidence level
was used to assess qualitative variables. Odds ratios (ORs) and stepwise logistic regression were used to calculate risk
estimates; the independent variables: age, gender, DMFT, CPI index, Geriatric Oral Health Assessment Index (GOHAI)
score, and tooth loss were included in the statistical model. P value <0.05 was considered a statistically significant cut-off.
No differences were found between females and males for DMFT and CPI. GOHAI data were worst for females. Patients
with CVD had less education and oral care (P < 0.05), and higher CPI index and number of missing teeth (P < 0.05). Data
show that patients with more than 18 missing teeth have 2.5 times greater risk of CVD. CVDs are associated with type
2 diabetes mellitus, underweight, and obesity (P < 0.05). From the findings of this study, it can be confirmed a significant
link between CVD and oral health. A cooperation among geriatrician, cardiologist, and dentist is suitable to counteract
the development of CVD and to early identify patients at risk of CVD
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