The Role of Porcelain Veneers in the Aesthetic Restoration of Discolored Endodontically Treated Teeth.

BACKGROUND: The discoloration of endodontically treated anterior teeth poses a significant aesthetic concern for many individuals, impacting their confidence and self-image. Porcelain veneers have emerged as a popular solution for the aesthetic restoration of such teeth. This paper explores the role of porcelain veneers in addressing tooth discoloration, examining their efficacy, durability, and aesthetic outcomes via a clinical case. CASE DESCRIPTION: In this clinical case, an aesthetic restoration of a discolored central incisor was performed using a ceramic veneer. Due to the high degree of discoloration, an internal bleaching of the tooth was carried out prior to the final restoration. Various factors influencing the selection of porcelain veneers as a treatment modality, including shade matching, preparation techniques, and adhesive bonding, are discussed. CONCLUSIONS: The advancements in materials and techniques have enhanced the versatility and aesthetic appeal of porcelain veneers, making them a valuable option for achieving natural-looking and durable aesthetic restorations in individuals with discolored endodontically treated anterior teeth.

Research on the Role of Surface Treatment of the Metal Surface on the Strength of the Metal-Ceramic Bond.

AIM: The aim of the present study is to investigate the metal-ceramic bond strength as a result of three different surface treatment methods: (1) oxidation, (2) oxidation and sandblasting, and (3) double oxidation on the metal substrate. MATERIALS AND METHODS: A total of 72 metal substrates were made from two different types of metal-ceramic alloys (n = 36): group I, Ni-Cr and group II, Co-Cr alloys. Each group was further divided and subjected to three different surface treatments (n = 12): (1) oxidation in accordance with the manufacturer's instructions; (2) oxidation according to the manufacturer's instructions and then sandblasting with Al2O3, with a grain size of 110 µm, a pressure of 75 psi for 10 sec with a distance of 5 cm and steam cleaning; and (3) double oxidation. The bond strength of the specimens was evaluated with the three-point bending process. The data were recorded, tabulated, and statistically analyzed. RESULTS: For group I, the materials with oxidation based on the specifications, show mean value of 64.02 Nt. The oxidation and sandblasting materials have mean 55.92 Nt. The double oxidation materials have mean 55.47. For group II, the materials with oxidation based on the specifications, show mean value of 58.46 Nt. The oxidation and sandblasting materials have a mean value of 42.56 Nt. The double oxidation materials have mean 42.96 Nt. CONCLUSION: The best method of treatment of the metal substrate is specification oxidation, in terms of the strength of the metal-ceramic bond. Further treatment of the metal substrate reduces the strength of the metal-ceramic bond. CLINICAL SIGNIFICANCE: A prerequisite for clinical success of metal-ceramic prosthetic restorations is the increased strength of the bond between ceramic material and metal substrate. With that in mind, the present research gives important insight into best practices for prosthetic restorations.

Clinical Longevity of Indirect Composite Resin Inlays and Onlays: An Up to 9-Year Prospective Study.

OBJECTIVE: This clinical study evaluated the clinical performance of composite resin inlays and onlays over 9 years. MATERIALS AND METHODS: Sixty composite resin inlays and onlays were placed in 32 patients, aged 20 to 60 years, by a single operator using the same clinical procedure. The restorations were examined for fracture rate; esthetics; and patient acceptance and marginal integrity, including caries, marginal discoloration, tooth integrity, and surface texture. All restorations were evaluated at the time of placement and 3, 6, and 9 years after placement by using the modified U.S. Public Health Service criteria. RESULTS: At the 3-year follow-up, an Alpha score was given to 88.4% of restorations, while a Bravo score was given to the remaining 11.6%. There was not any failure. At the 6-year follow-up, the success rate of the restorations was 100% without failure. None of the restorations was scored with Delta (D). An Alpha score was given to 60% of the restorations, a Bravo score was assigned to 35%, and a Charlie score was 5% of the restorations. Overall, the success rate of the restorations at 9-year follow-up was 85% and the failure rate was 15%. An Alpha score was given to 15% of the restorations, a Bravo score was given to 50%, a Charlie score was assigned to 20%, and a D score was given to 15% of the restorations. CONCLUSION: Indirect resin composite inlays and onlays showed acceptable long-term clinical results. The success rate of the restorations at 9-year follow-up was 85% and the failure rate was 15%.

Characterization of the Interface of Heat-pressed Glass-Ceramic Masses on Metal Support Cr-Co in Metal-Ceramic Prosthetic Restorations.

AIM AND OBJECTIVE: The aim and objective of this study is to evaluate the interface between heat-pressed glass-ceramic masses on a Cr-Co metal substrate using a scanning electron microscope and an X-ray energy dispersion spectrometer. MATERIALS AND METHODS: A pressed porcelain-leucite-based ceramic (IPS InLine press-on-metal (PoM); Ivoclar Vivadent AG) was used. Three cylindrical metal specimens cast (diameter 5 mm, height 1.5 mm) in Co-Cr alloy and covered with pressed ceramic (height 1.5 mm), according to the instructions of the manufacturer. All the specimens were covered with conductive carbon and then examined with a scanning electron microscope. The interface areas were studied using projections from an ETD secondary emission detector and a reversing atomic SSD contrast beam at a magnification of 1200× and 2000×, with a voltage 25 kV acceleration and 110 mA climb current. The elemental analysis was done with genesis 3.5 software, without the use of templates. Surface mapping areas and linear line scan projections of elemental distributions during the interface were recorded. RESULTS: The distribution of specific elements in the ceramic coating concludes the existence of ion diffusion from one side of the interface to the other, which leads to an initial conclusion of the development of primary bonds with oxygen bridges. Also, in the interface, there are ledges of the mass of opaquer on the metal substrate, which results in the creation of a mechanical bond. Therefore, the adhesive mechanism must be due to both micromechanical retention and wetting phenomena and is similar to the conventional layering technique. CONCLUSION: The PoM technique can be used as an alternative fabrication method for metal-ceramic restorations. Factors, such as material composition and properties, firing temperatures, cooling rates, operator's skill, porosities, and fabrication process, may affect the quality and strength of the bond between the core and the veneering materials. CLINICAL SIGNIFICANCE: The PoM technique can be used as an alternative fabrication method for metal-ceramic restorations.

Clinical evaluation of fractured metal-ceramic fixed dental prostheses repaired with indirect technique.

OBJECTIVES: Metal ceramic restorations continue to be widely used in dental practice, as they combine esthetics with superior mechanical properties. However, ceramic materials have the potential to fracture due to their brittle nature. The purpose of this study was to evaluate the clinical survival of fractured metal-ceramic restorations repaired with an indirect technique which uses a new "overlay" metal-ceramic crown that is luted to the existing restoration. METHOD AND MATERIALS: The study population consisted of 92 patients. Only patients with one or more fractured retainers of multipleunit metal-ceramic fixed partial dentures were involved in this study. In all cases there were a bulk fracture of the overlaying ceramic material and exposure of the underlying metal substructure. The remaining retainers of the fixed partial dentures were intact. The total number of fractured retainers was 106. All clinical procedures of the indirect repairs were carried out by a single investigator, according the previously published technique. The patients were examined clinically at 1, 2, 4, 6, and 8 years after placement of the new restorations. The repaired restorations were examined for debonding, fracture rate, and esthetics. Patient acceptance was also recorded. RESULTS: Of the 92 patients re-examined, all were satisfied with the function and the esthetic appearance of their restorations. None of the repaired restorations fractured after 8 years of service, and there were no gingival margin problems of significance. Four restorations debonded during the evaluation period. The overall survival rate was 96.2% after 8 years. CONCLUSION: Repair methodology and materials employed in this study resulted in satisfactory longevity for metal-ceramic dental prostheses. The success rate was 96.2% after 8 years. The retention rate was very good, patient satisfaction was very encouraging, and maintenance of the esthetics was good.