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Aim: The main aim of the present study was to compare and evaluate the effect of repetitive firings on different shades of a pressable all ceramic system layered with veneering porcelain. Setting and Design: In-vitro comparative study Materials And Methods: An in vitro comparative study was conducted, and a total of 60 disc shaped specimens (15 mm in diameter and 0.8 mm in thickness) were made of heat pressed ceramic of shades A2, A3, and B2 (20 discs of each shade) grouped as Group I, II, and III, respectively, using the lost wax technique. The discs were subsequently layered with veneering porcelain followed by glazing and overglazing and underwent a firing cycle at each step until six times combined. CIE L*a*b* measurements were noted on each sample after the third, fourth, fifth, and sixth firing using VITA Easyshade Advance 4.0 spectrophotometer. Statistical Analysis Used: Statistical Analysis was done by SPSS 17.0 software. One way analysis of variance, multiple comparisons using the Tukey test, and descriptive statistical analysis were done for all the groups in the study. P

Darkening of the dental crown is one of the consequences that most motivates patients to seek professional help. However, its management becomes challenging when having to mask a single tooth element in the oral cavity. The objective of this work was to report a clinical case of a patient, victim of dental trauma, which occurred 20 years ago, the consequences of which were the development of a periapical lesion and severe discoloration and darkening of the dental crown, in which there was an endodontic-dentistic interrelationship. for the success of the treatment. Endodontic retreatment was performed to control the infection and cementation of a fiber post and porcelain crown for aesthetic rehabilitation. After 12 months, it was possible to notice complete repair of the periapical lesion and aesthetic harmony of the smile, configuring the proposed treatment as a success. [ABSTRACT FROM AUTHOR]

Introduction: The final color of dental ceramics depends on different factors such as light source, substrate, and selected material (thickness, contour, and texture). Objective: To report a clinical case in which a predictable protocol is used to optimize the final color of porcelain laminate veneers. Case report: A male patient attended the dental clinic dissatisfied with the composite resin restorations made on his upper anterior teeth. After anamnesis and clinical examination, it was suggested that the resin restorations be replaced by laminated porcelain veneers. A diagnostic wax-up was performed. The mockup was also used to evaluate the aesthetic length for replicating the details of the incisal edge and the shape and size of the embrasures. The shade was selected before composite resin removal to avoid dehydration of the dental substrate. A photograph was taken to guide the selection of colors in different thirds. After removing the restorations, another photograph was taken to evaluate the color of the substrate. The impression was taken with 000 retractor wire and addition silicone. The laminates were made with pressed ceramic and feldspathic porcelain veneers were subsequently applied by layering the layers of dentin, incisal edge and enamel based on the waxing diagnosis. After approval by the patient, a conventional cementation technique was performed. The occlusal adjustment was made with rubber polishing cups and the anterior and lateral guides were checked. Conclusion: The protocol recommended for successful selection of the color of a porcelain laminate relies on the combination of knowledge of concepts, resources such as shade guides, spectrophotometers, and photographs, and porcelain application and characterization techniques performed by the technician and luting techniques by the dentist. [ABSTRACT FROM AUTHOR]

The present study aims to evaluate the indication of the use of feldspathic ceramics in posterior teeth, by the CAD/CAM technique (Computer-aided design [CAD] and computer-aided manufacturing [CAM]), in a public institution, through a literature review. An advanced search was carried out in the PubMed database, covering the last 15 years and using the following MeSH search terms: “dental crowns”, “CAD/CAM system”, “porcelain” and “review”. Thirty out of the 47 articles initially surveyed were selected to compose the final sample. From the present study, it was possible to conclude that the use of feldspathic ceramics developed by the CAD/CAM technique is safe in posterior teeth, whether the technique is respected. This technique is an excellent option for dental treatment in institutions of high restorative demand that have high levels of demand and readiness, promoting celerity, avoiding the use of temporary restorations, also reducing the number of urgencies in prosthesis

Background: Porcelain combined with zirconia core substructure has low fracture toughness. Nanoparticles are incorporated into the porcelain to boost its mechanical properties. Aims: To evaluate the effect of the incorporation of silver oxide and titanium oxide nanoparticles into porcelain powder on the bond strength of porcelain veneer to zirconia core. The flexural strength of nanoparticles-modified porcelain was also evaluated. Materials and Methods: The flexural strength of feldspathic porcelain was measured (according to ISO specifications number 6872) after the incorporation of silver and titanium oxide nanoparticles. For measuring the bond strength at the porcelain-zirconia interface, 70 bars (4 × 4 × 12 mm) of zirconia were cut and fired in a furnace. The control and nanoparticles-modified porcelain powders were built up on the zirconia bars and fired to create veneers of 3 mm height, 4 mm width and 4 mm thickness. The porcelain veneers were de-attached from the zirconia core by the universal testing machine. The failure load was recorded to calculate the bond strength. Statistical Analysis: The data were analysed with one-way analysis of variance followed by Tukey's test. Results: The addition of 0.5–1.5% silver oxide nanoparticles to feldspathic porcelain increased the flexural strength. The addition of 1.0–4.0% titanium oxide nanoparticles to feldspathic porcelain increased the flexural strength. Either 0.5–1.0% silver oxide or 3.0–4.0% titanium oxide nanoparticles in feldspathic porcelain increased the shear bond strength to zirconia core. Conclusion: The flexural strength of porcelain veneer and the bond strength at porcelain-zirconia interface can be improved by adding either 0.5% silver oxide nanoparticles or 4% titanium oxide nanoparticles to porcelain powder.

AimsThe aim of this project was to evaluate the effects of 2 different whitening strips on color, microstructure and roughness of tea stained porcelain and composite surfaces.Methods54 porcelain and 72 composite chips served as samples for timed application of over-the-counter (OTC) test or control dental whitening strips. Chips were divided randomly into three groups of 18 porcelain and 24 composite chips each. Of these groups, 1 porcelain and 1 composite set served as controls. The remaining 2 groups were randomized to treatment with either Oral Essentials® Whitening Strips or Crest® 3D White Whitestrips™. Sample surface structure was examined by light microscopy, profilometry and Scanning Electron Microscopy (SEM). Additionally, a reflectance spectrophotometer was used to assess color changes in the porcelain and composite samples over 24 hours of whitening. Data points were analyzed at each time point using ANOVA.ResultsIn the light microscopy and SEM images, no discrete physical defects were observed in any of the samples at any time points. However, high-resolution SEM images showed an appearance of increased surface roughness in all composite samples. Using profilometry, significantly increased post-whitening roughness was documented in the composite samples exposed to the control bleaching strips. Composite samples underwent a significant and equivalent shift in color following exposure to Crest® 3D White Whitestrips™ and Oral Essentials® Whitening Strips.ConclusionsA novel commercial tooth whitening strip demonstrated a comparable beaching effect to a widely used OTC whitening strip. Neither whitening strip caused physical defects in the sample surfaces. However, the control strip caused roughening of the composite samples whereas the test strip did not.

Aim: The aim of this study was to evaluate and compare the shear bond strength between ceramic layered over titanium and ceramic layered over cobalt-chromium alloy, which are used in the fabrication of screw-retained implant prosthesis. Settings and Design: In-vitro – Comparative study. Materials and Method: A total of 40 samples (20 samples of Titanium in Group 1 and 20 samples of Cobalt-Chromium in Group 2) were fabricated. For all the samples bonding agent was applied on to the sand blasted surface and firing was done at a temperature of 980° C. A layer of opaque was applied using a brush and placed back in the furnace at a temperature of 910° C. Then ceramic was layered on to the surface with putty index as guide and firing was done in the ceramic furnace up to a temperature of 880° C followed by glazing. Shear bond strength was measured using a Universal Testing Machine. Statistical Analyses Used: One sample t-test and paired sample t-test. Results: Descriptive statistics were done to calculate mean differences between groups and samples. The mean bond strength of titanium- ceramic samples was more than those of cobalt-chromium-ceramic samples. Inferential statistics used in the study were one sample t-test for intra-group comparison and paired sample t-test for inter group comparison which showed no statistically significant difference between the two metal types (P value = 0.163). Conclusion: The shear bond strength of ceramic veneered over titanium meets the ISO requirements of minimum shear bond strength between metal-ceramic systems and has achieved the clinically acceptable values. The use of titanium super structure over titanium implants reduces the adverse effects and avoids undesirable effects.

Purpose: The purpose of this study is to clarify the porcelain firing temperature conditions that give strongest bonding strength of porcelain to zirconia to manufacture all-ceramic fixed dental prostheses (FDPs) with excellent long-term stability.Methods: Opaque porcelain samples (8.0 × 3.0 × 1.2 mm) were placed in the center of zirconia plates (25.0 × 3.0 × 0.5 mm) and fired at temperatures of 950°C, 1,050°C, 1,100°C, and 1,150°C. Schwickerath crack initiation tests, elemental analyses, and morphological changes of the samples were compared.Results: There was no difference in the bonding strength among all the groups of porcelain fired at different temperatures. Elemental analysis of Si and O2 at the interface between the zirconia and porcelain were observed in the 950°C, 1,050°C, and 1,100°C groups. No silicon was found in the 1,150°C group by elemental analysis, and the zirconia plate where the porcelain sample was placed had irregular shape changes.Conclusion: It is suggested that silicon is also involved in chemical bonds due to firing at high temperatures. [ABSTRACT FROM AUTHOR]

Certain patients, despite receiving proper treatment, still show higher failure rates of restorative dental treatments. The aim of this work was to test if MMP2 and MMP3 alleles are overrepresented in individuals with secondary caries. A total of 1,089 individuals from the University of Pittsburgh School of Dental Medicine Dental Registry and DNA Repository project were selected for this study. From this total, 341 individuals were selected for having a record of secondary caries in any type of restoration and were matched with 748 individuals by sex, age, ethnicity, and restorative work in the same teeth that did not fail. Genomic DNA extracted from saliva was used to obtain genotypes in five markers of MMP2 and MMP3 using TaqMan chemistry and end-point analysis. Chi-square was used to test if differences in allele and genotype distributions were statistically different at an alpha of 0.05. The less common allele and homozygote genotype of MMP2 rs9923304 were less commonly found among individuals with secondary caries. The less common allele of MMP2 rs2287074 was also less frequent among individuals with secondary caries. These results provide statistical evidence for the role of MMP2 in failure of restorations due to secondary caries. We can conclude that MMP2 variation impacts the risk of having secondary caries, independent of the restorative material.

Background: Considering the increase in demand for orthodontic treatment in adults, bracket bond to restored teeth is a clinical challenge. This study sought to compare the shear bond strength (SBS) of orthodontic brackets to feldspathic porcelain using universal adhesive and conventional adhesive with and without silane application. Materials and Methods: In this in vitro study Fifty-six feldspathic porcelain discs were roughened by bur, and 9.6% hydrofluoric acid was used for surface preparation. Samples were divided into the following four groups (n = 14): Group 1: universal adhesive, Group 2: universal adhesive/silane, Group 3: conventional adhesive, and Group 4: conventional adhesive/silane. Mandibular central incisor brackets were bonded, and SBS was measured by Instron® machine. To assess the mode of failure, adhesive remnant index (ARI) score was determined. The data were analyzed using SPSS software and two-way ANOVA, Bonferroni test, and Kruskal–Wallis test (P < 0.05 considered significant). Results: The highest SBS was noted in the universal adhesive/silane group (12.7 MP) followed by conventional adhesive/silane (11.9 MP), conventional adhesive without silane (7.6 MP), and universal adhesive without silane (4.4 MP). In the absence of silane, the conventional adhesive yielded significantly higher SBS than universal adhesive (P = 0.03). In the presence of silane, the two adhesives showed SBS values significantly higher than the values obtained when silane was not applied, while the two adhesives were not significantly different in terms of SBS in the presence of silane (P = 0.53). Based on ARI score, there were statistically significant differences between Groups 1 and 4 (P = 0.00) and Groups 2 and 4 (P = 0.023). Conclusion: Based on the current results, SBS of bracket to porcelain mainly depends on the use of silane rather than the type of adhesive. Both universal and conventional adhesives yield significantly higher SBS in the presence of silane compared to that in the absence of silane.

Background: Porcelain veneer restoration is the primary choice for indirect restoration, especially for anterior teeth, given its high esthetic properties and lower failure rate than resin composites. Glass-based ceramics such as IPS e.max Press and Vintage LD Press are a choice for veneer due to its superior physical properties. Resin cement is used to attach the veneer restoration to the teeth. The polymerization of resin cement used in veneer restoration affects the stability, mechanical properties, and resistance of the restoration. The composition and thickness of the porcelain material affect the light-curing unit to cured resin cement. Objectives: The aim of this study was to evaluate the influence of porcelain thickness, light intensity, and exposure time in the hardness of resin cement. Methods: Porcelain samples measuring 5 mm in diameter with three types of thicknesses of IPS e.max Press and Vintage LD Press were used in the study. Resin cement in a metal mold was placed under a porcelain sample before curing with a light-emitting diode (LED) intensity of 1300 or 1700 mW/cm2. The hardness test was then carried out on the bottom of the resin cement. Result: The highest hardness value was obtained from a Vintage LD Press with a thickness of 0.7 mm (cured at 1300 mW/cm2 for 20 s). A four-way ANOVA test showed significant differences for brands, thicknesses, and times of exposure (P < 0.05) as well as insignificant difference for LED intensity. Conclusion: The study indicates that polymerization of resin cement with lower thickness presented higher hardness values. Irradiation time affected hardness, while LED intensity did not.

Objective:The aim of the present study was to compare the shear bond strength (SBS) of metal orthodontic brackets bonded to long-term water-aged and fresh porcelain and composite surfaces.Methods:One porcelain (Vitadur Alpha (VA)) and three composite (Filtek Ultimate (FU), Tetric EvoCeram (TEC), and Gradia Direct Anterior (GDA)) materials were evaluated in the present study. First, 10 discs from each material were prepared and subjected to the aging procedure for 5 years. Then, for comparison, another 10 discs from each material were prepared as fresh surfaces and stored in distilled water for 24 h. Metal brackets were bonded to the prepared disc surfaces, and after being stored in water for 24 h, they were subjected to shear bond test using a universal testing machine. Adhesive remnant index (ARI) scores were obtained by examining the disc surfaces under a stereomicroscope at 10× magnification. Kruskal-Wallis test was used to compare the aged and fresh groups.Results:Although the difference between the SBS between the aged and fresh groups with VA, FU, and TEC was not significant, the SBS was significantly higher in the fresh group with GDA. With regard to ARI scores, there was no significant difference between the aged and fresh groups with FU and GDA, whereas the ARI scores of the aged groups with VA and TEC were higher.Conclusion:It was concluded that the aged restoration materials have a distinctive influence on the SBS of metal orthodontic brackets.

The article focuses on a technique for creating rich white teeth that possesses richness and transparence by applying porcelain on the dentin base layer. It notes that while it would be possible to achieve 100% light transmission in a vacuous state, 100% pure transparent object does not exist. It says that even snow white and transparence represent opposite ends of the spectrum, both are physiologically categorized as colorless without having hue and chroma. It assesses that the dentin porcelains in the market have shade guides (SG) which varies from lower, similar, or higher value. Moreover, when there were differences in value between the natural teeth and SG, the result could be final restorations having incorrect value but with similar chromacity to the natural teeth.

The article offers information on using porcelain laminate veneers in teeth rehabilitation. It stresses that veneers are bonded on minimally invasive preparations, usually on enamel. According to the article, despite having a well-established record of success as esthetic and functional restorations, some rules should be followed and the case must be selected carefully. The article discusses the standard preparation in using porcelain laminate veneers and in which situations these should be used including on improperly aligned teeth.

The article describes the case of a 26-year old female model with teeth damages, said to be unacceptable for her age and profession. According to the article, the treatment plan was to replace her porcelain-fused-to-metal crowns with all-ceramic crowns. The article also presents pictures of the progress of the treatment.

Porcelain laminate veneers are widely accepted as the treatment of choice to noninvasively restore the esthetics and function of anterior teeth, provided there is a sufficient amount of tooth structure to support the reconstruction. However, there are certain esthetic limitations if the underlying tooth structure is discolored, which may occur in cases of nonvital roots. This article describes how to manage this esthetic challenge. Internal bleaching, tooth-colored internal buildups, and preparation guidelines are discussed via clinical case presentations. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the use of new adhesive/primer materials, including an experimental self-etch primer and a cyanocrylate adhesive, to enhance the shear strength of orthodontic brackets bonded to porcelain surfaces. Material and Methods: Sixty porcelain maxillary central incisor teeth were used. The teeth were randomly divided into four groups: group 1, teeth were etched with 37% phosphoric acid and the brackets were bonded with a composite adhesive; group 2, teeth were microetched, hydrofluoric acid and silane applied, and then the brackets were bonded with a composite adhesive; group 3, an acid-etch primer was used, then the brackets were bonded with the same composite adhesive as in the first 2 groups; group 4, teeth were etched with 35% phosphoric acid and the brackets were bonded with the cyanoacrylate adhesive. Results: The analysis of variance comparing the groups tested (F = 9.446) indicated that there was a significant difference between the 4 groups. The cyanoacrylate adhesive had the lowest shear bond strength (mean = 1.7 ± 2.1 MPa), followed by the conventional bonding using a 37% phosphoric acid etch and composite (mean = 2.1 ± 1.2 MPa). The use of Transbond after microetching, with the application of hydrofluoric acid and silane, provided the highest shear bond strength (mean = 5.5 ± 2.7 MPa). Transbond used with the acid etch-primer had a lower bond strength (mean = 3.8 ± 2.5 MPa), but was not significantly different from the microetch/hydrofluoric acid/silane group. Conclusion: The results indicated that the use of a phosphoric acid etch with either a cyanoacrylate or composite adhesive to bond orthodontic brackets to porcelain surfaces produced significantly lower shear bond strength. Self-etch primers produced higher but less consistent shear bond strength for bonding orthodontic brackets. The most reliable bonding procedure to porcelain surfaces is through microetching with the use of hydrofluoric acid and a silane coupler before bonding, but this also produces the greatest damage to the porcelain surface. [ABSTRACT FROM AUTHOR]

Background: Composite resin (CR) currently is one of the most commonly used material in restoring noncarious cervical lesions (NCCL) due to its strength and esthetics color but has microleakage problem. The aim of this study is to compare in vitro the microleakage depth between CR and porcelain in restoring NCCL. Materials and Methods: This an in vitro study was done by preparing cavities on the buccocervical surface of 62 extracted premolar teeth which randomly assigned to two groups (n = 31) where Group 1 was restored with nanocomposite and Group 2 was cemented with porcelain cervical inlays. They were then subjected to thermocycling before immersion in 2% methylene blue dye for 24 h. Dye penetration depths were measured using Leica imaging system For statistical analysis, independent t-test was used to analyze the results (P < 0.05). Results: Porcelain cervical inlay restorations demonstrated statistically lesser microleakage depth for the cervical margins (P = 0.018) when compared to CR. Deeper microleakage depth at the cervical compared to coronal margins of CR (P = 0.006) but no significant difference of both margins for porcelain cervical inlays (P = 0.600). Conclusion: Porcelain cervical inlays show lesser microleakage than CR which could be alternative treatment option in restoring NCCL with better marginal seal and esthetics.

The color accuracy of resin composite cements and their corresponding try-in pastes was assessed. Three shades of three brands were compared using the cements alone and in contact with a standard porcelain disk. There were significant differences in color between resin cements and their corresponding try-in pastes. The addition of a 1-mm-thick porcelain disk greatly reduced the apparent color differences. The color of resin cements changed over time but not significantly. Baseline measurements of resin cement colors were compared and measurements made after 24 hours of storage. Color changes were statistically significant but not perceptible, and all samples became slightly darker with age. [ABSTRACT FROM AUTHOR]

The surface roughness of Vita VMK porcelain following oven glazing and eight grinding/polishing treatments was analyzed qualitatively using scanning electron microscopy and quantitatively using a profilometer. Techniques were selected to simulate clinical practice. Scanning electron microscopy evaluation found oven glazing produced a better surface than other polishing methods. On the basis of the profilometric examination, the best roughness average value was obtained using diamond instruments with progressively smaller particle sizes (30, 15, and 8 μm). Scanning electron microscopy analysis showed that all the treatments left the surfaces partially porous and cracked; however, the glazed surface yielded the best result. Although no significant differences were detected for the different treatments, the use of a 30-μm diamond instrument produced a rougher surface. No correlation was found between scanning electron microscopy and profilometer results. This study suggests that several procedures may be used to effectively finish ceramic surfaces. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine how surface treatments and moisture affect the flexure strength of a high-leucite feldspathic porcelain. Uniaxial flexure strength was measured for porcelain beams whose surfaces were coarse ground, overglazed, or polished. Hall of the specimens were stored in distilled water and tested while their surfaces were coated with distilled water. The other half were stored in a dry environment and tested immediately in dry air. The high-leucite feldspathic porcelain was found to be sensitive to roughness and surface stresses, similar to leucite-tree and low-leucite feldspathic porcelains. The experimental method used, however, was not sensitive enough to detect susceptibility to moisture. [ABSTRACT FROM AUTHOR]

The tensile bond strength of inlay materials to dentin was evaluated. Five materials, two direct resin composite inlay products, one hybrid resin composite, a preformed ceramic block, and a conventional porcelain material were bonded to bovine dentin and bonded together using a dual-polymerizing resin luting agent. Specimens were tested with and without thermocycling. Some bar to bar bonding groups fractured through the bar. Significantly higher (P < .05) bar-to-bar bonds were recorded than the bar-dentin bonds, irrespective of the inlay materials. VitaDur N showed the lowest bar-to-bar failure values (7.6 MPa) compared to the four other inlay materials (14.4 MPa to 22.2 MPa), but had the highest dentin bond strength (4.5 MPa). Unexpectedly, thermal loading increased the bond strength to bovine dentin, although this was only statistically significant for VitaDur N. The dentin bond strength of Charisma (1.4 MPa) was inferior (P< .02) to all other materials (26 MPa to 4.5 MPa) when thermocycled before testing. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the stress corrosion fatigue characteristics of a heat-pressed ceramic material, IPS-Empress. Disks (1 mm thick, 12 mm in diameter) were prepared, polished, and subjected to dynamic loading at multiple constant stressing rates. Fatigue tests were conducted in a circulating bath using a biaxial flexure test. The inert strength of the samples was determined in oil. The mean fracture strength for the inert tests was 1 35.7 MPa. Linear regression analysis of log fracture strengths vs log time to failure was performed to obtain fatigue parameters. For IPS-Empress then value was 31 SE 3.5) and σf0 was 83.3 MPa SE 1.3 MPa). [ABSTRACT FROM AUTHOR]

The purpose of this study was to demonstrate the ability of Kubelka-Munk reflectance theory to predict color parameters of veneer porcelain on various backings using colorimetric measurements. Tristimulus absorption and scattering coefficients were used to predict the respective tristimulus reflectance values of A1, D3, and translucent porcelain samples after they had been bonded to light and dark substrates using universal, opaque, and untinted shades of bonding resin. Observed and predicted reflectance values exhibited high correlation (r² ≥ 0.93 for each porcelain shade). Kubelka-Munk theory offers an accurate prediction for the resultant colorimetric reflectance parameters of veneer porcelain bonded to variously colored backings. [ABSTRACT FROM AUTHOR]

This study evaluated the fracture resistance of three types of all-ceramic crowns and compared these to the fracture values of metal ceramics. Uniform metal ceramic specimens; veneered, cast glass-ceramic; and porcelain fused to two different dispersion-strengthened ceramic cores (Hi-Ceram and In-Ceram) were investigated. The metal ceramic specimens demonstrated a significantly higher resistance to fracture than did the Hi-Ceram or veneered glass-ceramic units but did not significantly differ from the In-Ceram specimens. The metal ceramic crowns showed cracks only in the ceramic layer, whereas the all-ceramic specimens underwent global fracture. [ABSTRACT FROM AUTHOR]

One goal in metal ceramic substructure design is strengthening the restoration. This investigation compared the strength of four metal ceramic crown designs advocated in the dental literature. Metal ceramic crowns were fabricated, luted to a master die, and loaded to failure on a mechanical testing machine. Crowns with a facial veneer of porcelain covered occlusally with metal withstood significantly higher failure loads than did the other designs. These were followed by crowns having the porcelain extended to the central groove, crowns with facial porcelain veneers without occlusal metal coverage and, the weakest group, crowns with complete occlusal porcelain coverage. There were no significant differences between the latter three designs. [ABSTRACT FROM AUTHOR]

Eight intraoral porcelain repair systems, ie, Oral Ceram-Etch (Gresco), Scotchprime (3M), Rocatec (ESPE), Command Ultrafine (Kerr), Silistor (Kulzer), Clearfil Porcelain Bond (J Morita), All-Bond (Bisco), and Monobond S (Vivadent) were used in this study. The control specimens consisted of unetched porcelain surfaces onto which a resin composite was polymerized without the use of an adhesive. Load fatigue was used as the testing method to simulate the repetitive action of mastication. The peak stress applied to each test specimen was 1500 psi (10.34 MPa), and an upper limit on the number of load cycles applied to any specimen was set at 2,000,000 cycles. Statistical analysis revealed two significant subsets. Only Clearfil Porcelain Bond and All-Bond did not fail before reaching the 2,000,000-cycle upper limit. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of porcelain surface treatment on the shear bond strength of composite resin to various porcelains and porcelain combinations. A variety of feldspathic porcelains with low and medium alumina content were tested. Porcelain/composite resin samples were stored in 37°C water, thermocycled 1,000 times, and tested in shear. A 3-minute etching using hydrofluoric acid significantly increased the bond strength of most of the feldspathic porcelains with low and medium alumina content. Silane application to all types of etched porcelain had no significant effect on bond strength. [ABSTRACT FROM AUTHOR]

A method for selecting the optimal shade of a ceramic restoration is presented. The shade is determined using a direct approach, facilitating communication with the laboratory. The dentist generates a custom shade tab using unfired dental porcelain powder mixed with an organic binder which has a refractive index that is adjusted to the fired material. Hue, chroma, value, and translucency are verified by direct comparison with the tooth to be replicated. Necessary adjustments are ascertained prior to fabricating the restoration, minimizing postfabrication alterations. [ABSTRACT FROM AUTHOR]

The article discusses esthetic restoration for anterior teeth with the use of a ceramo-metal restoration having a labial butt-joint. It notes the prerequisite for the fabrication of a natural-looking anterior restoration which include a proper and appropriate preparation of the finish line area of the abutment. It also presents a step-by-step instruction for the build-up and correction of this restoration which include the application of a spacer on the stone die, the exposition of labiogingival shoulders without covering it with wax, and the application of shoulder powder which could become the butt-joint porcelain shoulder.

The article focuses on the use of photography in dentistry. For quality control before and after shots should be taken as part of the patient's records. These records dictates that the after shot not embarrass the dentist. It is stated that the value of recall and the degree of patient involvement can be increased by before and after shots. The author says that he uses an 18 % gray card to select shades for porcelain jackets. It is stated that It is stated that an intra-oral photo with a lot of gadgetry should not be taken without very special reason or unless the slide is needed for teaching other dentists.

Objective: The overall clinical performance of porcelain veneers was evaluated at 5 years. Method and materials: Porcelain veneers were placed on 87 maxillary anterior teeth in 25 patients (19 to 69 years) by a single operator following a standardized clinical procedure. At the 5-year recall, esthetics, marginal performance, vitality, fracture rate, and patient satisfaction were recorded. Results: At recall, 93% of the veneers were satisfactory without intervention. The remaining 7% presented clinically unacceptable problems such as recurrent caries, porcelain fracture, severe clinical microleakage, or pulpal reaction. The retnetion rate of the porcelain veneers was 100%, and the maintenance of esthetics was perfect . Only 14% of the veneers presented excellent marginal adaptation over the entire outline of the restoration; however, the impact of the slight marginal defects on the clinical performance was negligible. Conclusion: Labial porcelain veneers offer a reliable and effective procedure for the conservative treatment of discolored, malformed, and malaligned anterior teeth. [ABSTRACT FROM AUTHOR]

Aims: The aim of this study was to evaluate and compare the shear bond strength of porcelain to the alloys of nickel-chromium (Ni-Cr), cobalt-chromium (Co-Cr), and titanium. Materials and Methods: A total of 40 samples (25 mm × 3 mm × 0.5 mm) were fabricated using smooth casting wax and cast using Ni-Cr, Co-Cr, and titanium alloys followed by porcelain buildup. The samples were divided into four groups with each group containing 10 samples (Group A1–10: sandblasted Ni-Cr alloy, Group B1–10: sandblasted Co-Cr alloy, Group C1–10: nonsandblasted titanium alloy, and Group D1–10: sandblasted titanium alloy). Shear bond strength was measured using a Universal Testing Machine. Statistical Analysis Used: ANOVA test and Tukey's honestly significance difference post hoc test for multiple comparisons. Results: The mean shear bond strength values for these groups were 22.8960, 27.4400, 13.2560, and 25.3440 MPa, respectively, with sandblasted Co-Cr alloy having the highest and nonsandblasted titanium alloy having the lowest value. Conclusion: It could be concluded that newer nickel and beryllium free Co-Cr alloys and titanium alloys with improved strength to weight ratio could prove to be good alternatives to the conventional nickel-based alloys when biocompatibility was a concern.

Objective: The aim of the study was to make an inventory of current literature on the bond strength between zirconia and veneering porcelain after surface treatment of zirconia by grinding with diamond bur and/or with airborne-particle abrasion. Material and methods: The literature search for the present review was made following recommended guidelines using acknowledged methodology on how to do a systematic review. The electronic databases PubMed, Cochrane Library, and Science Direct were used in the present study. Results: Twelve studies were selected. Test methods used in the original studies included shear bond strength (SBS) test, tensile bond strength test, and micro-tensile bond strength test. The majority of studies used SBS. Results showed a large variation within each surface treatment of zirconia, using different grain size, blasting time, and pressure. Conclusions: Airborne-particle abrasion might improve the bond strength and can therefore be considered a feasible surface treatment for zirconia that is to be bonded. Grinding has been recommended as a surface treatment for zirconia to improve the bond strength; however, this recommendation cannot be verified. A standardized test method and surface treatment are required to be able to compare the results from different studies and draw further conclusions.

Aim and Objectives: Effective finishing and polishing of dental restorations provides for oral health, function and aesthetics. There are studies which state that porcelain should be glazed after chairside adjustments, whereas, some studies advocate that polishing is equivalent or better than glazing. The main objective of this study was to compare glazing and polishing, and also, to compare three different polishing systems available in the Indian market, namely SHOFU, DFS and DIATECH. Materials and Methods: One hundred twenty six specimens of porcelain discs were prepared and divided into 3 groups with subsequent subgroups. Quantitative analysis was done using a profilometer to determine the roughness quotient (Ra value) and qualitative analysis was done using a Scanning Electron Microscope (SEM). Result: It was found out that glazing produces smoother surfaces as compared to polishing. Among the three different polishing systems used, SHOFU was found to produce the most smooth surfaces. Conclusion: The polished surface provided by the polishing kits was not comparable to the smoothness of the glazed surface and cannot substitute for glazing.

Background: Porcelain fracture is the most important problem in fixed prosthetic restorations. The replacement of fractured restoraions isn't often prefer by patients and dentists. Intraoral repair of fractured porcelain is a big alternative for patient and dentist. For this reason, dentists try to improve different surface treatments to increase the bond strength between porcelain and repair materials such as composite resins. Aims: The aim of this study was to evaluate the shear bond strength (SBS) of nano-hybrid (Nh.com) and nano-ceramic composite resins (Nc.com) to this feldspathic porcelains (Vita and Ivoclar). Settings and Design: 120 ceramic disc were fabricated from feldspathic porcelain. Materials and Methods: The following surface treatment was applied on the ceramic surface: 1) Hydrofluoric acid+silane, 2) Air-abrasion+silane, 3) Air-abrasion=Control group. Nh.com and Nc.com was placed on the porcelain surface. Half of the specimens were stored in 37 ± 2oC distilled water and another half were subjected to thermocycling before SBS. The samples placed in an universal testing machine and applied shear force until seperation occured. Statistical analysis used: The data were analyzed by multi-way analysis of variance (ANOVA) and Duncan test (P

Background. Any decrease in friction between orthodontic wire and bracket can accelerate tooth movement in the sliding technique and result in better control of anchorage. This study was carried out to evaluate frictional forces by coating orthodontic wires and porcelain brackets with zinc oxide nanoparticles (ZnO). Methods. In this in vitro study, we evaluated a combination of 120 samples of 0.019×0.025 stainless steel (SS) orthodontic wires and 22 mil system edgewise porcelain brackets with and without spherical zinc oxide nanoparticles. Spherical ZnO nanoparticles were deposited on wires and brackets by immersing them in ethanol solution and SEM (scanning electron microscope) evaluation confirmed the presence of the ZnO coating. The frictional forces were calculated between the wires and brackets in four groups: group ZZ (coated wire and bracket), group OO (uncoated wire and bracket), group ZO (coated wire and uncoated bracket) and group OZ (uncoated wire and coated bracket). Kolmogorov-Smirnov, Mann-Whitney and Kruskal-Wallis tests were used for data analysis. Results. The frictional force in ZZ (3.07±0.4 N) was the highest (P

Background and aims. Use of porcelain as inlays, laminates and metal-ceramic and all-ceramic crowns is common in modern dentistry. The high cost of ceramic restorations, time limitations and difficulty of removing these restorations result in delays in replacing fractured restorations; therefore, their repair is indicated. The aim of the present study was to compare the shear bond strengths of two types of composite resins (methacrylate-based and silorane-based) to porcelain, using three adhesive types. Materials and methods. A total of 156 samples of feldspathic porcelain surfaces were prepared with air-abrasion and randomly divided into 6 groups (n=26). In groups 1‒3, Z250 composite resin was used to repair porcelain samples with Ad-per Single Bond 2 (ASB), Clearfil SE Bond (CSB) and Silorane Adhesive (SA) as the bonding systems, afterapplication of silane, respectively. In groups 4‒6, the same adhesives were used in the same manner with Filtek Silorane composite resin. Finally, the shear bond strengths of the samples were measured. Two-way ANOVA and post hoc Tukey tests were used to compare bond strengths between the groups with different adhesives at P

Introduction. The objective of this in-vitro study was to compare the accuracy, defined as trueness and precision, of an intraoral scanner and a cast scanner belonging to the same manufacturer (Dental Wings, Montreal, Canada). Materials and methods. An experimental model consisting of a die with a standard preparation for a porcelain fused to a metal crown was manufactured from a disk of polymethylmethacrylate resin, through CAD/CAM milling. The PMMA model was digitized by using an industrial CT in order to obtain the digital reference model. Afterwards, the resin model was scanned 15 times with each scanner, following manufacturer's instructions. In order to asses trueness, comparisons were performed with the digital reference model while, for precision, the first scan in the series was compared with the following scans. Results and disscusion. When the trueness of the included scanners was tested, the average deviation for the laboratory scanner was 9.85 μm and 20.85 μm, respectively, for the intraoral scanner. As for precision, the mean recorded deviations were 6.32 μm for the laboratory scanner and 17.18 μm for the intraoral scanner. For both fidelity and trueness, F and T tests demonstrate a statistically significant difference between the scanners. Conclusions. Within the limits of this study, we can state that a significant difference was observed between the accuracy displayed by the scanners tested in this study, mainly generated by the different capturing techniques used by each scanner. [ABSTRACT FROM AUTHOR]

With the growth of cosmetic dental procedures, the practise of dentistry has become increasingly centred on fulfilling patient desires. Porcelain veneers are increasing in popularity among today’s patients and dental practitioners for conservative restoration of unaesthetic anterior teeth. The ability to place restorations without significant removal of structure is becoming more critical than ever. Besides being painless and conservative, it is a durable material and doesn’t stain like composite making it attractive for a much longer period of time thus making contemporary dentistry, increasingly oriented toward elective and cosmetic procedures. [ABSTRACT FROM AUTHOR]

Purpose of the Study: The purpose was to evaluate the effect of various surface treatments and sandblasting with different particle size on the bond strength of feldspathic porcelain with predominantly base metal alloys, using a universal testing machine. Materials and Methods: Totally, 40 specimen of nickel-chromium alloy were prepared in an induction casting machine. The groups divided were as follows: Group I-sandblasted with 50 μ Al 2 O 3 , Group II-sandblasted with 110 μ Al 2 O 3 , Group III-sandblasted with 250 μ Al 2 O 3 and Group IV-sandblasted with 250 μ Al 2 O 3, followed by oxidation and again sandblasted with 250 μ Al 2 O 3 . The dimensions of each specimen were adjusted so as to maintain the thickness of ceramic at 1 mm. The specimen were loaded on the assembly of the universal testing machine, and a cross head speed of 0.5 mm/min was used to apply a compressive force at the junction of metal and feldspathic porcelain. The force application continued until adhesive fracture occurred, and the readings of the load applied to that particular specimen were recorded. Results: The means for shear bond strength for Group I, II, III and IV were found to be (226.92 ± 1.67), (233.16 ± 3.85), (337.81 ± 16.97) and (237.08 ± 4.33), respectively. Means of shear bond strength among the groups were compared using one-way analysis of variance test. Comparison between individual groups were made with Tukey′s Honestly Significant Difference post-hoc test. Conclusion: Different particle size and surface treatment have an important role on the bond strength of ceramic-metal interface. Greater particle size demonstrated higher bond strength.

Introduction: Intraoral chair side porcelain repair system is a quick, painless and highly patient acceptable procedure, without removal of restoration or fabrication of new restoration. There are very limited studies conducted to evaluate the shear bond strength of repair systems after different surface treatment. Objectives of Research: The objective of research was to evaluate the shear bond strength of two intraoral porcelain repair systems Clearfil repair system (Kuraray) and Ceramic repair system (Ivoclar) to repair metal-ceramic restoration after three different surface treatment. Materials and Methods: Totally, 120 discs of base metal alloy were fabricated. The opaque, dentine and enamel of ceramic were applied to achieve the uniform thickness. Defect was created, and repair was done using two repair systems after different surface treatment. Shear bond strength was measured. Results: Analysis of variance was utilized. Ceramic repair system after 40% phosphoric acid surface treatment showed the highest mean value and Clearfil repair system after surface treatment with 37% phosphoric acid showed the lowest. The statistical difference was found to be significant between the groups. Conclusion: The shear bond strength of Ceramic repair system with 40% phosphoric acid etching showed highest shear bond strength as compared to other system and surface treatment used in the study.

Recently, effects of rapidly developing technology have been seen in the dentistry. Advances in materials enable minimally invasive treatments in which dental tissue is preserved in order to provide esthetics. Porcelain laminate veneer technique, one of the minimally invasive treatments, is the most popular treatment today. Porcelain laminate veneers stand out with having translusity close to tooth and high biocompatibility properties. In this case report, stages of porcelain laminate veneer technique are described in detail. [ABSTRACT FROM AUTHOR]

Introduction: The selection of porcelain is based on high biocompatibility, endurance, superficial texture and aesthetics. Nevertheless, the innate fracture charateritics of porcelain is the main cause of the intra oral fractures. Electing a suitable porcelain restorative system in terms of stability of color is important. For this reason, this study aimed to examine the color changes of common porcelain repair materials . Methods: Using a silicon mold, 30 pieces of feldspathic porcelain in A3 color, 10mm of diameter and 2 mm of thickness were prepared. The samples were randomly distributed into three groups : Group 1: Porcelain-Silane-Bonding-Composite Group 2: Porcelain-Silane-Bonding-Panavia F 2.0-Bonding-Silane-Porcelain Group 3: Porcelain-Silane-Bonding-Choice 2 -Bonding-Silane-Porcelain The aging process was accomplished with thermocyling (3000 cycles, 5/55 degree), incubation in 37° and 100° humidity. Thereafter, discoloration was assessed In CIE system via designation of color transforming matrix in MATLAB environment . Results: The average quantitative amount of discoloration at day 0, 90 and 180 were 76.8±0.57, 79.15±0.52, 80.13±0.6 for Choice, 78.03±0.9, 79.42±0.82, 80.17±0.51 for Panavia, and 78.41±1.53, 79.59±0.77, 81.03±0.63 for Composite, respectively. The color changes by the time were significant for the all three groups (p

This article encompasses the variety of all ceramic materials available now a days and their clinical applications. It will help the clinicians understand the advantages and disadvantages of different types of ceramic materials available based on their microstructure, processing method and usage area. Although PFM or Porcelain fused to metal crowns had rampant use because of their long-term clinical success rate, the quench for more esthetic, more biocompatible materials led the way for the usage of new all-ceramic crowns-a new age dentistry destination. [ABSTRACT FROM AUTHOR]

Background: Bonding of molar tubes is becoming more popular in orthodontics. Occasionally, these bonding are done on posterior porcelain crowns or bridges. The purpose of this study was to evaluate the shear bond strength of buccal tubes on feldspathic porcelain crowns with two different methods. Materials and Methods: Forty porcelain right molar crowns were fabricated for this study. The crowns were randomly divided into two groups. In group 1, the crowns were etched with 9.6% hydrofluoric acid, silane coupling agent applied, coated with bonding primer and bonded with Transbond XT (3M Unitek, Monrovia, Calif). In group 2, the crowns were etched with phosphoric acid 37%, silane coupling agent applied, coated with bonding primer and bonded with Transbond XT. All the crowns were stored for 24 hours at 37°C and thermo-cycled before the shear bond test. The analysis of variance (ANOVA) was used to determine whether significant difference were present between the groups. Results: The results of the analysis of variance (F = 0.23) indicated the shear bond strength of group 1 (3.57 ± 0.87 MPa) was not significantly different ( P > 0.05) from group 2 (3.46 ± 0.65 Mpa). Fisher′s exact test for the adhesive remnant index (ARI) revealed significant difference between both groups ( P < 0.05). Eighty percent of group 1 buccal tubes failed at buccal tube/resin interface and eighty percent of group 2 mostly failed at porcelain/resin interface. Conclusion: Etching with phosphoric acid with the use of silane coupling agent would be safer and should make it easier for clinicians to clean the adhesive on the porcelain surface after debonding.

The availability of zirconium dioxide (zirconia) ceramics in dentistry has expanded the range of designs and applications for all-ceramic restorations and increased its popularity. This article reviews the literature on the bond strength between layering materials and zirconia frameworks used in dental restorations. Database searches were conducted for in vitro studies of bond strength between layering materials and zirconia frameworks. The search was carried out in different electronic databases, supplemented by handsearch in dental journals and by examination of the bibliographies of the retrieved articles. A variety of studies on bond strength was identified, including comparisons with metal–ceramic systems and studies on mismatched coefficients of thermal expansion, the use of press-on ceramics or liner materials, and the effect of cooling time after firing. The available data provide considerable information on achieving stable layering of material/zirconia composites. However, only a few in vitro studies on bond strength between indirect composites and zirconia were identified. Such studies and additional controlled clinical trials are needed.