PubMed Health⌕ Search

PubMed · 10850265

All-ceramic restorations: classification and clinical evaluations.

Abstract

In the search for alternative and esthetic restorative materials, many all-ceramic systems have been introduced for the general practitioner. They are used as veneers, inlays/onlays, crowns, and as enamel/dentin bonded partial or total coverage without macroretention. This article describes a classification of the different commercial all-ceramic systems and gives a review of their clinical durability. Reasons for failures are given for the different restorations. Fracture is the main reason for failure, especially for all-ceramic crowns and inlays. The frequency of secondary caries contiguous to resin composite luted ceramics is very low. Wear of the luting agent, called ditching, is not an enduring clinical problem. The use of certain ceramic materials as well as luting agents have been shown to be contraindicated, especially in molar teeth. Newer reinforced ceramics showed better durability then the earlier fired ceramic reconstructions.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

J W van Dijken. 1999. All-ceramic restorations: classification and clinical evaluations.. https://pubmed.ncbi.nlm.nih.gov/10850265/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Cementable implant crowns composed of cast superstructure frameworks luted to electroformed primary copings: an in vitro retention study.

OBJECTIVE: The aim of this in vitro study was to investigate, on ITI solid abutments, the retention values of single crowns fabricated using an alternative prosthetic solution: secondary cast superstructure luted to an electroformed primary coping. MATERIALS AND METHODS: Fifty standard 4.1 mm ITI implants and 5.5 mm high ITI machined abutments were assembled and mounted in acrylic resin. Implant/abutment assemblies were randomly divided into two groups. In the test group, primary galvanic caps were directly fabricated on implant abutments (A.G.C. Micro machine), and a secondary cast noble alloy superstructure was luted on each primary galvanic cap with a resin cement (Nimetic Cem). In the control group, prefabricated burn-out caps were used for casting the metal frameworks. Test and control crowns were cemented using a resin cement (Panavia 21). After storage at 37 degrees for 24 h, the specimens were subjected to a pull-out test using an Instron universal testing machine. The load required to dislodge each sample and the respective mode of failure were recorded. Means and standard deviations of loads at failure were analyzed using ANOVA. Statistical significance was set at P< or =0.05. RESULTS: The retention values (+/-SD) of loads at failure were 67.26 (+/-16.61) for the test group and 44.03 (+/-9.45) for the control group. In the test group no separation occurred between the electroformed (galvanic) primary cap and the secondary superstructure. CONCLUSIONS: The results showed that this prosthetic solution is superior on retentive performance than the conventional cast framework. An added clinical advantage of this novel method is its potential to provide a totally passive fit. Further in vitro and in vivo studies involving multiple-unit restorations are needed in order to more generally validate this prosthetic concept.

Cementation↗

Intra-operative evaluation of cementless hip implant stability: a prototype device based on vibration analysis.

Cementless implants are mechanically stabilized during surgery by a press-fitting procedure. Good initial stability is crucial to avoid stem loosening and bone cracking, therefore, the surgeon must achieve optimal press-fitting. A possible approach to solve this problem and assist the surgeon in achieving the optimal compromise, involves the use of vibration analysis. The present study aimed to design and test a prototype device able to evaluate the primary mechanical stability of a cementless prosthesis, based on vibration analysis. In particular, the goal was to discriminate between stable and quasi-stable implants; thus the stem-bone system was assumed to be linear in both cases. For that reason, it was decided to study the frequency responses of the system, instead of the harmonic distortion. The prototype developed consists of a piezoelectric exciter connected to the stem and an accelerometer attached to the femur. Preliminary tests were performed on four composite femurs implanted with a conventional stem. The results showed that the input signal was repeatable and the output could be recorded accurately. The most sensitive parameter to stability was the shift in resonance frequency of the stem-bone system, which was highly correlated with residual micromotion on all four specimens.

Cementation↗