A biomechanical analysis of different types of implant connections is relevant to clinical practice because it may impact the longevity of the rehabilitation treatment. Therefore, the objective of this study is to evaluate the Morse taper connections and the stress distribution of structures associated with the platform switching (PSW) concept. It will do this by obtaining data on the biomechanical behavior of the main structure in relation to the dental implant using the 3-dimensional finite element methodology. Four models were simulated (with each containing a single prosthesis over the implant) in the molar region, with the following specifications: M1 and M2 is an external hexagonal implant on a regular platform; M3 is an external hexagonal implant using PSW concept; and M4 is a Morse taper implant. The modeling process involved the use of images from InVesalius CT (computed tomography) processing software, which were refined using Rhinoceros 4.0 and SolidWorks 2011 CAD software. The models were then exported into the finite element program (FEMAP 11.0) to configure the meshes. The models were processed using NeiNastram software. The main results are that M1 (regular diameter 4mm) had the highest stress concentration area and highest microstrain concentration for bone tissue, dental implants, and the retaining screw (P<0.05). Using the PSW concept increases the area of the stress concentrations in the retaining screw (P<0.05) more than in the regular platform implant. It was concluded that the increase in diameter is beneficial for stress distribution and that the PSW concept had higher stress concentrations in the retaining screw and the crown compared to the regular platform implant.
Objective
The objective of this systematic review was to evaluate
the efficacy of non-surgical periodontal therapy on rheumatoid arthritis
activity.
Material and methods
Articles published until April 2019 were electronically
searched and screened using PubMed / MEDLINE, Scopus, and Cochrane databases
according to the Preferred Reporting Items for Systematic Reviews and
Meta-Analyses guidelines (PRISMA). This study was recorded in the international
PROSPERO database (CRD42019132205). The PICO question (population, intervention,
comparison, results) was: in adult patients with rheumatoid arthritis and
periodontitis (P), does non-surgical periodontal treatment (I), as compared to
no treatment (C), provides better outcomes in rheumatoid arthritis activity
(O).
Results
After searching the databases, seven articles were
selected for qualitative and five for quantitative analysis. The total number of
participants included was 292, with an average age of 50.5 years. All patients
had rheumatoid arthritis and periodontal disease. Non-surgical periodontal
treatment significantly reduced Disease Activity Score 28 (P = 0.004;
I
2
= 92%) and erythrocyte sedimentation rate (P = 0.01;
I
2
= 78%), but with no significant effect on C-reactive
protein (P = 0.34; I
2
= 92%).
Conclusions
It can be concluded that non-surgical periodontal
treatment can benefit patients with rheumatoid arthritis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.