Effect of conventional and microwave glazing on surface roughness of metal ceramics: An atomic force microscopy analysis

This study investigated and compared the surface roughness achieved by glazing porcelain samples in a conventional and a microwave oven. Materials and Methods: Two commercial brands of metal ceramics were used, VITA VMK MASTER and IPS CLASSIC. Sixty samples were fabricated, 30 for each type of ceramic. The samples were sintered in the conventional oven and hand-polished to remove any irregularities. Samples (n = 10) from each type of ceramic were further divided into three groups as follows: hand-polished (Group A), conventional oven glazed (Group B), and microwave glazed (Group C). Each specimen was evaluated for surface roughness by atomic force microscope. Data were statistically analyzed using two-way analysis of variance (ANOVA) and Tukey's post hoc test (a = 0.05). Results: Two-way ANOVA indicated a highly significant difference in surface roughness based on the type of glazing (P < 0.001), there was a significant difference based on the metal ceramics (P = 0.002). There was also a significant interaction between the type of glazing and metal ceramics (P = 0.009). The images obtained from the atomic force microscope corroborated the measured values. Conclusions: All the results indicate that microwave glazing can be a feasible option for glazing porcelain specimens. It was concluded that surface topography is influenced by surface treatment and microwave glazed ceramic is superior to conventional oven glazed ceramic and hand-polishing showed greater surface roughness when compared to glazing. IPS CLASSIC ceramic showed relatively smooth surface when compared to VITA VMK MASTER irrespective of the surface treatment.

Modern trends in modeling of extra-oral defects.

Maxillofacial prostheses are usually fabricated on the basis of conventional impressions and techniques. The extent to which the prosthesis reproduces normal facial morphology depends on the clinical judgment and skill of the individual fabricating the prosthesis. Recently, as a result of advances in technology, various computer-aided design and manufacturing techniques have been successfully introduced for the automated fabrication of maxillofacial prostheses. These systems are able to provide more consistently accurate reproduction of facial morphology.

Implant crest module: A review of biomechanical considerations.

The success of dental implants has long been established through various studies with a particular emphasis laid on an implant design. Crest module is that portion of a two-piece metal dental implant, designed to hold the prosthetic components in place and to create a transition zone to the load bearing implant body. Its design, position in relation to the alveolar crest, and an abutment implant interface makes us believe that, it has a major role in integration to both hard and soft tissues. Unfortunately, in most clinical conditions, early tissue breakdown leading to soft tissue and hard tissue loss begins at this region. Early crestal bone loss is usually highest during the first year after placement ranging from 0.9 to 1.6mm and averaged 0.05-0.13mm in the subsequent years . Various hypotheses have been stated to reason it however, none has been proved convincingly. In light of this, various attempts have been made to overcome this undesirable bone loss, by varying an implant design, the position, surgical protocol, and the prosthetic options. Irrespective of an implant system and designs that are used, crestal bone loss of up to the first thread is often observed. The purpose of this review is to look into the various designs and treatment modalities, which have been introduced into the crest module of an implant body to achieve the best biomechanical and esthetic result.

Validation of implant stability: A measure of implant permanence.

Implant stability is a requisite characteristic of osseointegration. Without it, long-term success cannot be achieved. Continuous monitoring in a quantitative and objective manner is important to determine the status of implant stability. Measurement of implant stability is a valuable tool for making decisions pertaining to treatment protocol and also improves dentist-patient communication. Owing to the invasive nature of histological analysis, various others methods have been proposed like radiographs, cutting torque resistance, reverse torque, modal analysis, resonance frequency analysis and Implatest® . This review focuses on objectives and various methods to evaluate implant stability.

Overdenture with accesspost system: A clinical report.

A patient presented with an unfavorable distribution of teeth in the arch which precluded treatment with a removable partial denture. The unique pattern of partial edentulism was treated with an overdenture restoration using accesspost system. The final restoration was stable, well retained and esthetic, serving as a conservative approach to root preservation.