No abstract

This in vitro study was conducted to evaluate the interaction between the shear bond strength and the surface treatment method for a commercial dental ceramic. Ninety bonded ceramic units were manufactured for this study. Each unit was made by luting two cylinder-shaped ceramic samples to each other with a resin-composite luting agent. The units were then divided into nine groups, containing 10 units in each group. Samples from each group were treated with one of the following: etching with 4.9% hydrofluoric acid for 10, 20 and 40 s, 9.5% hydrofluoric acid for 10, 20 and 40 s, 40% orthophosphoric acid for 40 s, air abrasion with alumina in 50-microm particles, and grinding with a high-speed diamond bur. The treated samples were then silanated and luted with a resin-composite luting agent. The luted units were then loaded to failure. Two samples from each group were neither silanated nor luted after the surface treatment procedure, and morphological changes obtained by various surface treatment regimens were investigated by scanning electron microscopy. A statistically significant difference was observed among the mean shear bond strengths of the groups prepared with different surface treatment techniques (P = 0.00). Hydrofluoric acid appeared to be the most suitable chemical medium to produce a reliable ceramic bond. Etching time and concentration of the acidic medium were also observed as important prognostic variates. Orthophosphoric acid treatment was observed to be the least effective surface treatment method on the heat-pressed ceramic samples. Physical applications such as bur grinding and air blasting maintained stronger bonds than the orthophosphoric acid, while producing weaker bonds than surfaces treated with hydrofluoric acid in all concentrations and etching periods. The effect of the silane priming agent was not considered in this study.

This in-vitro study compared the marginal and internal fit and also the microleakage of zirconia infrastructures (Procera All-Zircon, Cercon Smart Ceramics) in contrast to heat-pressed ones (Empress 2).Thirty maxillary premolars (n=30) were divided into three groups (n=10) and prepared with individual chamfer preparations by using the silicone index method. Plaster dies of 10 individual preparations were allocated to each coping fabrication method of computer-aided design and computer-aided manufacturing (Procera), computer-aided manufacturing (Cercon) and heat pressing (Empress 2) as the control. All the specimens were kept in distilled water at room temperature for four weeks after cementation with dual-curing resin cement (Variolink II, Ivoclar-Vivadent). They were then thermocycled between 5°C to 55°C for 5000 cycles with a 20-second dwell time and immersed in 0.5% basic fuchsin for 48 hours. The cemented specimens were separated into two halves vertically in the midvestibulo-palatal direction. The specimens were examined under a computer-aided stereomicroscope to evaluate both the internal and marginal fit. Marginal and internal gap widths were measured at 100× magnification. The specimens were evaluated for microleakage under a stereomicroscope at 100 × magnification. Selected specimens from each group were also examined using a scanning electron microscope. Fitting accuracy data were analyzed statistically with the Welch test and the Post-hoc Dunnett C-test (p<0.05). The microleakage data were analyzed with the Kruskal-Wallis test. Special software (SPSS/PC+ Version 10.0, SPSS, Chicago, IL, USA) was used for statistical evaluations.Differences between the marginal and internal fitting accuracy of the tested non-veneered infrastructures were found to be statistically significant (p<0.05). However, there were no significant differences in microleakage among the groups (p=0.273).

No abstract

Prosthetic rehabilitation of a total glossectomized patient and specifications of the appliance, which differs from those previously reported, are presented. The functional considerations and logic used to design such a device are described. Speech performance of the patient with and without the prosthesis, is compared with a perceptibility test. Improvement of the functions of mastication, swallowing and speech were found acceptable.

This article has been retracted because of duplicate publication in different journals.

This clinical report describes a clinical and laboratory method for producing a new functional splint combining a MAS and a tongue-retaining device with a custom-made tongue-tip housing and discusses the rationale for using such a device.

The patient's tolerance was increased with the new overdenture.