<strong>Aim of the study.</strong> Marginal fit of the all ceramic chair side CAD CAM inlays evaluation.
<strong>Materials and methods.</strong> Inlay class II standardized preparations were performed on twelve natural teeth (molars) which were adapted and fixed on a typodont. Scanning of the cavities was done (Planmeca FIT) and the milling of the inlays was realized (Planmeca Mill 40). Light body silicone (Fit Checker II, GC, Tokyo, Japan) was injected on the preparations of the typodont model, and then each of the Empress CAD inlays were seated on the abutments under finger pressure, reproducing the clinical situation of the luting process. The marginal gap between the all ceramic inlays and the cavities was measured using microscopic photos of the silicone fit checker between the inlays and the cavities in 12 points/restoration. A calibration scale and imaging computer software (Image J) were used for the measurements.
<strong>Results</strong> The values measured for the occlusal cavity (marginal occlusal) were ranged between 19.026µ and 139.669µ and the values for the vertical cavity (marginal cervical) ranged between 69.256 µ and 295.091. Marginal openings below 100μ-120μ are clinically acceptable so there where some problems regarding the cervical fit.
Conclusion</strong> Within the limits of this study there were some cases with poor cervical marginal fit. Extensive studies could be useful for more accurate evaluations.
Digital impressions were introduced in order to overcome some inconveniences related to
conventional impression materials.The aim of this in vitro study is to determine and evaluate the way
the abutment geometry influences the accuracy of both, digital and conventional impressions. Crown
preparations with occlusal convergence angles (0,6,10 and 20 degrees) were created from 4 resin
maxillary right incisors.Each preparation was scanned using a high resolution scanner (reference
scanner) and saved in stereolithography (STL) format. Then the prepared resin teeth were scanned
(PlanScan group) using an intraoral scanner and saved in STL format as well.A number of three
conventional polyvinyl siloxane (PVS) impressions were made from each preparation, which were
poured with Type IV dental stone and scanned using the same intraoral scanner (PVS group). All
STL files were compared using metrology software (Geomagic Studio 2013), in terms of trueness
and precision. Based on the findings in this study, it may be concluded that the accuracy of digital
impressions is superior to conventional methods, but the difference between them is not significant.
Dental prosthetic restorations have to satisfy high stress as well as aesthetic requirements. In order to avoid deficiencies
of dental prostheses, several alternative systems and procedures were imagined, directly related to the material used and
also to the manufacturing technology. Increasing the biomechanical comportment of polymeric materials implies fiber
reinforcing. The different fibers reinforcing products made very difficult the evaluation of their performances and
biomechanical properties analysis.
There are several known methods which are used to assess the quality of dental prostheses, but most are invasive. These
lead to the destruction of the samples and often no conclusion could be drawn in the investigated areas of interest. Using
a time domain en-face OCT system, we have recently demonstrated real time thorough evaluation of quality of various
The aim of this study was to assess the quality of various polymeric materials used in dental technology and to validate
the en face OCT imagistic evaluation of polymeric dental prostheses by using scanning electron microscopy (SEM) and
microcomputer tomography (μCT).
SEM investigations evidenced the nonlinear aspect of the interface between the polymeric material and the fiber
reinforcement and materials defects in some samples. The results obtained by microCT revealed also some defects inside
the polymeric materials and at the interfaces with the fiber reinforcement.
The advantages of the OCT method consist in non-invasiveness and high resolution. In addition, en face OCT
investigations permit visualization of the more complex stratified structure at the interface between the polymeric
material and the fiber reinforcement.
The complete dentures are currently made using different technologies. In order to avoid deficiencies of the prostheses
made using the classical technique, several alternative procedures have been devised. In order to enhance the mechanical
strength, complete denture bases are reinforced with fibres. Their material and structure vary wildly, which makes the
investigation difficult. In this study, optical coherence tomography (OCT) is evaluated as a possible non-invasive
technique to assess the biomechanical behaviour of the reinforcing fibres. OCT images demonstrate structural defects
between fibres and the acrylic material in all dentures bases investigated. We conclude that OCT can successfully be
used as a noninvasive analysis method.