An esthetic approach to anterior segments: crown restorations following a subepithelial connective tissue graft procedure.

Achieving good esthetics while maintaining healthy surrounding tissues in fixed partial dentures (FPDs) is difficult, especially in the maxillary anterior region. Any unfavorable relationship between the residual ridge, pontic, and gingival papilla often compromises the final result. Alternative procedures can be developed to improve these relationships and provide esthetic and functionally acceptable FPDs. Using soft tissue grafts to correct an esthetic deficiency may be a feasible approach for establishing new and stable gingival and papilla contours. Altering the shape of a residual ridge by gradual hydropressure is another promising technique to improve tissue contour.

Effect of different surface-cleaning techniques on the bond strength of composite resin restorations.

STATEMENT OF PROBLEM: Different techniques have been suggested for cleaning dentin surfaces after the removal of an interim prosthesis and before the application of a bonding agent. How different surface-cleaning techniques affect the bond strength of the composite resin restorations is not clear. PURPOSE: The purpose of this study was to investigate the effects of different surface-cleaning techniques on the bond strength of composite resin restorations and the surface topography of the prepared tooth surfaces. MATERIAL AND METHODS: The occlusal surfaces of 25 molars were ground until the dentin was exposed. A bonding agent and interim cement were applied on the teeth. The teeth were divided into 5 groups (n=5) according to the method used for surface-cleaning (microairborne-particle abrasion, alcohol, rubber-rotary instrument, desiccating agent, and control). Once the surfaces of the teeth had been cleaned, the same bonding material was applied to the teeth. A 5-mm-thick composite resin layer was built up. Each specimen was sectioned to microbars, and 6 centrally located beams were selected for microtensile testing (n=30) (1.10 ±0.10 mm). The data were statistically analyzed with 1-way ANOVA (1-sample Kolmogorov-Smirnov test). The Bonferroni test was used for significantly different groups (α=.05). One specimen from each group was observed under a scanning electron microscope and an atomic force microscope. Energy dispersive x-ray analysis also was performed. RESULTS: Bond strength values were in the following descending order: microairborne-particle abrasion, desiccating agent, alcohol, rubber-rotary instrument, control. Differences between the microairborne-particle abrasion group and the remainder of the groups, desiccating agent--rubber-rotary instrument, desiccating agent-control, alcohol--rubber-rotary instrument, and alcohol-control groups, were statistically significant (P<.05). The microairborne-particle abrasion group displayed the roughest surface and a different surface topography from the remainder of the groups. Increased aluminum was observed in the microairborne-particle abrasion group. CONCLUSIONS: Surface-cleaning techniques, except for the rubber-rotary instrument, increased the bond strength of composite resin. The roughest dentin surfaces and highest bond strength were achieved with the microairborne-particle abrasion technique.

A clinical comparison of cordless and conventional displacement systems regarding clinical performance and impression quality.

STATEMENT OF PROBLEM: It is not clear whether newly introduced cordless displacement systems are better able to manage gingiva than conventional systems. PURPOSE: The purpose of this in vivo study was to evaluate the gingival management ability of 4 different displacement methods with a standardized subgingival preparation finish line. MATERIAL AND METHODS: The effects of 4 displacement techniques on gingival management and impression quality were evaluated by means of 6 evaluation criteria. A subgingival preparation finish line of between 1 and 2 mm was ensured, and the buccal aspects of 252 (n=63) teeth were clinically assessed for ease of application, time spent, bleeding, remnants, and dilatation. The complete reproduction of the preparation finish line and the bubble and void formations on polyether impressions were also evaluated. The data were statistically analyzed with the χ(2) test (α=.05). The Bonferroni correction was used to control Type I error for the pairwise comparison groups (α=.008). RESULTS: Statistically significant differences were found for all criteria among the groups (P<.05). The nonimpregnated displacement cord group was the least effective group in terms of bleeding and impression quality (P<.008). The aluminum chloride impregnated cord group and the displacement paste with cap group were found to be comparable in terms of remnants, dilatation, and impression quality (P>.008). The retraction cap with paste group showed better results for ease of application, time spent, and bleeding than the aluminum chloride impregnated cord group (P<.008). Although the group with aluminum chloride impregnated cord, displacement paste, and cap showed better results for dilatation, it was time consuming and difficult (P<.008). CONCLUSIONS: Except for the nonimpregnated cord group, all of the groups were comparable and clinically useful, with perfect or acceptable impression qualities.

Maxillary rehabilitation with a CAD/CAM-fabricated, long-term interim and anatomic contour definitive prosthesis with a digital workflow: A clinical report.

The digital workflow in this clinical report describes a maxillary rehabilitation with an articulator-free and definitive cast-free treatment protocol for computer-aided design and computer-aided manufacturing (CAD/CAM) fabricated long-term interim and anatomic contour monolithic lithium disilicate definitive restorations.

A hybrid classification model for digital pathology using structural and statistical pattern recognition.

Cancer causes deviations in the distribution of cells, leading to changes in biological structures that they form. Correct localization and characterization of these structures are crucial for accurate cancer diagnosis and grading. In this paper, we introduce an effective hybrid model that employs both structural and statistical pattern recognition techniques to locate and characterize the biological structures in a tissue image for tissue quantification. To this end, this hybrid model defines an attributed graph for a tissue image and a set of query graphs as a reference to the normal biological structure. It then locates key regions that are most similar to a normal biological structure by searching the query graphs over the entire tissue graph. Unlike conventional approaches, this hybrid model quantifies the located key regions with two different types of features extracted using structural and statistical techniques. The first type includes embedding of graph edit distances to the query graphs whereas the second one comprises textural features of the key regions. Working with colon tissue images, our experiments demonstrate that the proposed hybrid model leads to higher classification accuracies, compared against the conventional approaches that use only statistical techniques for tissue quantification.

A three-appointment alternative treatment protocol for fabricating an implant-supported milled bar overdenture.

This article describes an alternative impression technique for the fabrication of an implant-supported bar overdenture using the duplicated satisfactory interim denture as a custom tray for the implant-level impression. The primary advantage of this technique is that all the information needed for the definitive prosthesis fabrication is obtained from the interim denture and then transferred to the laboratory in a single appointment. However, this technique may be contraindicated for severely misaligned implants that require extensive reduction of the duplicated denture.

Management of interproximal soft tissue with a resin-bonded prosthesis after immediate implant placement: a clinical report.

This report describes immediate implant placement after the extraction of a vertically fractured tooth. During the healing phase, a resin-bonded prosthesis was inserted as a provisional restoration. After the creation of the optimal emergence profile and papillae with the provisional restoration, the definitive metal ceramic crown was fabricated.

A resampling-based Markovian model for automated colon cancer diagnosis.

In recent years, there has been a great effort in the research of implementing automated diagnostic systems for tissue images. One major challenge in this implementation is to design systems that are robust to image variations. In order to meet this challenge, it is important to learn the systems on a large number of labeled images from a different range of variation. However, acquiring labeled images is quite difficult in this domain, and hence, the labeled training data are typically very limited. Although the issue of having limited labeled data is acknowledged by many researchers, it has rarely been considered in the system design. This paper successfully addresses this issue, introducing a new resampling framework to simulate variations in tissue images. This framework generates multiple sequences from an image for its representation and models them using a Markov process. Working with colon tissue images, our experiments show that this framework increases the generalization capacity of a learner by increasing the size and variation of the training data and improves the classification performance of a given image by combining the decisions obtained on its sequences.