Mohamed Aboras

Types of Failures in Porcelain-Fused-to-Metal Dental Restoration

Porcelain-fused-to-metal (PFM) restoration is a type of dental prosthesis introduced since the early 1960s. This prosthesis is strong, aesthetically satisfactory, and affordable. This study aims to classify the types of failures observed in PFM prostheses that were constructed in a dental laboratory in Misrata, Libya. Data from six months of laboratory fabrication and clinical observation were collected. Approximately 12% of the PFM prostheses demonstrated the following defects: bubbles (31%), fractures and cracks in the porcelain (25%), chipping (13%), porosity (13%), shade defects (13%), and fractures in the metal framework (6%). These defects can impair PFM restorations. Hence, future studies must determine the cause of these defects and improve the materials used for dental restorations.

Type of Failure of Zirconia-Based Ceramics in Dental Laboratory in Misurata, Libya

Zirconia (ZrO2) is used to fix restorations as a core material because of its mechanical properties, aesthetics, and compatibility. This study aims to analyze the failure types in ZrO2-based restoration fabricated in a dental laboratory in Misurata, Libya. Data were collected from laboratory records for a 30-day period with follow-up for five months. About 6% of the total restorations had defects with different percentages, 46% of which were fractures, 29% of which had weak bonding between ZrO2 frameworks and veneers, 18% of which had cracks, and 7% of which had shade defects. Although ZrO2 is a suitable material for dental restorations, defects may occur and lead to the failure of dental restorations. A thorough study is necessary to analyze the cause of failurein zirconia-based restorationsand to improve the properties to produce a versatile dental restorative material.

A review of the low-temperature degradation of dental zirconia

The use of tetragonal zirconia as a dental restorative material has recently increased because of its unique mechanical and optical properties, as well as high biological compatibility with the oral cavity environment. However, the mechanical properties of zirconia can be severely degraded, which leads to the failure of dental restorations. This review focuses on the low-temperature degradation of dental zirconia and its effects on the properties of zirconia and on the oral environment. The purpose is to show the importance of this negative phenomenon and suggest guidelines for minimizing the aging of zirconia that is used as a dental restoration material.

Properties and survival rate of all ceramics dental crown: A review

All-ceramic dental crown restoration is popular because it results in better aesthetic quality than metal alloy restoration. Ceramics also show superior biocompatibility and inertness to human biological systems. However, clinical experience indicates that all-ceramic crowns are not as durable as their porcelain-fused-to-metal counterparts, particularly on molar teeth. New ceramic biomaterials that combine durability with excellent aesthetic qualities have been developed. In this study, several promising bioceramics for dental crown applications are evaluated and compared. The evaluated parameters include strength of the material, survival rate in clinical performance, and aesthetic quality.