50 research outputs found
PRADER-WILLI SYNDROME: ORAL FINDINGS
Aim: Prader-Willi syndrome is a rare multisystemic genetic disorder
caused by lack of expression of certain paternal genes
located on chromosome 15.
The syndrome, associated to hypothalamic and pituitary disfunction,
is characterized by severe neonatal hypotonia and
feeding problems. Neonatal hypotonia is followed, during
childhood by hyperphagia and obesity. In addition, hypothalamic
alterations can cause intellectual disability, behavioral
problems, a high pain threshold, respiratory sleep disorders.
The aim of this work is to evaluate the main dental aspects and
the therapeutic implications.
Methods: an analysis of the literature was performed using
databases.
Results: common clinical findings: gingivitis and periodontitis,
dental and skeletal malocclusions, enamel hypoplasia, tooth wear
and dental erosion, bruxism, xerostomia, candidiasis and angular
cheilitis, high risk of caries and increased DMFT score.The typical
poor oral hygiene in PWS patients is related to qualitative-quantitative
changes in saliva and incoordination in tooth brushing.
Conclusion: it is necessary to motivate family and patient to
maintain oral hygiene. Due to the various systemic and dental
problems, a six-monthly follow-up is required since early childhood.
Dental treatment purposes require a multidisciplinary
approach which includes periodontal and conservative cares.
In prosthetics, we suggest the use of removable dentures because
of the difficulty in maintaining oral hygiene
EXPERIMENTAL EVALUATION OF INTRAORAL SCANNERS IN EDENTULOUS MANDIBLES
Aim: the main difficulties for intraoral scanners (IOS) are found in
the edentulous mandibles. The reduced bucco-lingual surface, the
limited height of the bone crest and the mobility of the soft tissues
generate criticalities for the acquisition of the digital impression.
The purpose of this study is to evaluate the comparison between
digital and analog impressions in these particular conditions.
Methods: two scans were obtained for the 11 subjects. The first
intraoral scan was carried out with intraoral scan (Omnicam
DentsplySirona) and the second was acquired by digitizing a plaster
model, obtained from an impression taken with an analogue
method, the best choice in these cases. All scans were converted
to standard tessellation language (STL). The STL files obtained for
each patient were superimposed by means of the GEOMAGIC
Control X software, to evaluate the comparison.
The average distance values obtained through the Geomagic
3D software constitute our primary outcome measure. 1 sample
t-test was used to prove the hypothesis that the average
distances of the points obtained between the two files are relevant
(α = .05).
Results: concerning the scans ability to reproduce the analog
impression the intraoral scans carried out with a intraoral scan
generated files with single measurements in terms of minimal
distance between objects far from scans obtained with analogue
methods (t =-7.29, P < .001).
Conclusion: regarding the results obtained, it was possible to
conclude that the STL files deriving from digital impressions
are significantly different from those deriving from analog impressions,
highlighting a difference between the two methods
Pencarian File Gambar Berdasarkan Dominasi Warna
. Image File Searching Based on Color Domination. One characteristic of an image that can be used in image searching process is the composition of the colors. Color is a trait that is easily seen by man in the picture. The use of color as a searching parameter can provide a solution in an easier searching for images stored in computer memory. Color images have RGB values that can be computed and converted into HSL color space model. Use of HSL images model is very easy because it can be calculated using a percent, so that in each pixel of the image can be grouped and named, this can give a dominant values of the colors contained in one image. By obtaining these values, the image search can be done quickly just by using these values to a retrieval system image file. This article discusses the use of the HSL color space model to facilitate the searching for a digital image in the digital image data warehouse. From the test results of the application form, a searching is faster by using the colors specified by the user. Obstacles encountered were still searching with a choice of 15 basic colors available, with a limit of 33% dominance of the color image search was not found. This is due to the dominant color in each image has the most dominant value below 33%.Ă‚
DIGITAL TECHNOLOGIES IN COMPLETE REMOVABLE DENTURE: A CASE SERIES
Aim: complete removable denture has been the last prosthetic
procedure to follow the digitization because of drawbacks into
the intraoral scans of edentulous arches; in addition, it is impossible
to record muco-compressive impressions through
IOS. So, a full digital procedure is not yet conceivable.
We considered the possibility of an “hybrid” protocol thanks to
a specific software. The hybrid protocol requires traditional
techniques for the anatomical impression followed by laboratory
scan of casts and wax.
Methods: the software consists in two synergic programs:
- Ruthinium Digital Preview allows to have a picture of the prosthetic
project and change it previously, thanks to two calibrated
photographs.
- Ruthinium Denture Guide is a 3D software that helps laboratory
work into denture production, particularly to a correct setting of
acrylic teeth. The planned dental setting is printed in a template.
Template and base plate, both 3D printed, are connected thanks
to a structure that ensures the designed occlusal scheme.
Results: the collected clinical cases did not allow a statistic
analysis about patient and clinical satisfaction through evaluation
questionnaires.
Conclusion: it looks like that patients appreciate the prosthetic
rehabilitation previsualization and in particular being actively
involved in aesthetic choices. Clinically, it appears to be a
shorter need for touch-ups at the last appointment; probably
because of the 3D tooth position planning
The influence of custom-milled framework design for an implant-supported full-arch fixed dental prosthesis: 3D-FEA sudy
The current study aimed to evaluate the mechanical behavior of two different maxillary prosthetic rehabilitations according to the framework design using the Finite Element Analysis. An implant-supported full-arch fixed dental prosthesis was developed using a modeling software. Two conditions were modeled: a conventional casted framework and an experimental prosthesis with customized milled framework. The geometries of bone, prostheses, implants and abutments were modeled. The mechanical properties and friction coefficient for each isotropic and homogeneous material were simulated. A load of 100 N load was applied on the external surface of the prosthesis at 30° and the results were analyzed in terms of von Mises stress, microstrains and displacements. In the experimental design, a decrease of prosthesis displacement, bone strain and stresses in the metallic structures was observed, except for the abutment screw that showed a stress increase of 19.01%. The conventional design exhibited the highest stress values located on the prosthesis framework (29.65 MPa) between the anterior implants, in comparison with the experimental design (13.27 MPa in the same region). An alternative design of a stronger framework with lower stress concentration was reported. The current study represents an important step in the design and analysis of implant-supported full-arch fixed dental prosthesis with limited occlusal vertical dimension