Four-point flexural strength and microtensile bond strength of digitally and conventionally veneered zirconia.

This study intended to evaluate the effect of digital veneering on four-point flexural strength (FS) and microtensile bond strength (µTBS) of veneered zirconia. Two different zirconia blocks, a lithium disilicate and a feldspathic ceramic block, and two different layering ceramics were used. IPS e.max Zir CAD (ZC) and Vita In-Ceram YZ (YZ) with yttria stabilized tetragonal zirconia polycrystals (3Y-TZP) were used as substructures. IPS e.max CAD (LD), Vita Mark II (VMII), IPS e.max Ceram (EC) and Vita VM9 (VM9) were used for veneering. Resin cement and fusion ceramic were placed between veneer and zirconia substructure for digital veneering. A total of one hundred and fifty specimens in five groups (n = 30) were prepared for FS and tested in universal machine at 1.0 mm/min. One hundred specimens in five groups (n = 20) were obtained for the µTBS and tested at 1.0 mm/min. Statistical analysis was made by one way ANOVA and Tukey HSD. Conventional veneering showed statistically significant FS. ZC veneered with EC had the highest mean FS and the lowest was obtained in groups veneered through resin cement. YZ layered with VM9 had the highest mean µTBS. ZC veneered through fusion ceramic and YZ veneered through resin cement showed significantly lower and similar µTBS.

Clinical protocol for intraoral repair of a chipped all-ceramic crown: a case report.

Ceramic chipping occurs frequently in veneered all-ceramic crowns, and the decision to repair or replace them depends on many factors. The least invasive method is the intraoral repair. This case report describes a conservative restorative treatment performed on a chipped dental crown. A 59-year-old patient fractured her all-ceramic crown, revealing chipping and debonding of the feldspathic ceramic veneer and exposure of the zirconia framework. The fractured fragment was brought to the dental office. Due to the patient's esthetic concerns about prolonged treatment, it was decided to use the fragment to repair the crown intraorally. The result exceeded the patient's expectations. The intraoral repair of a chipped all-ceramic crown is a conservative and low-cost alternative that allows for immediate restoration of the function and esthetics. It is essential to establish protocols that can support clinician decision-making about the most appropriate clinical treatment, seeking the longevity of the restoration and the dental structure.

Comparison of the Color Change of Porcelain Laminate Veneers Produced by Different Materials After Luting with Three Resin Cements.

OBJECTIVES: This study aimed to compare color change of porcelain laminate veneers fabricated with two lithium disilicate ceramics and a zirconia-reinforced lithium silicate ceramic material after luting with conventional dual-cure, amine-free dual-cure, or light-cure resin cements using artificial accelerated aging (AAA). METHODS AND MATERIALS: Ninety noncarious human maxillary central incisors were embedded in autopolymerizing acrylic resin blocks to prepare conventional laminate veneers with incisal coverage. Prepared teeth were randomly divided into 3 groups (n=30) to fabricate laminate veneer restorations using: (1) lithium disilicate ceramic, (2) lithium disilicate ceramic with high-density micronization, and (3) zirconia-reinforced lithium silicate ceramic. Impressions of the preparations were taken with a laboratory scanner. Acquired 3D images were processed into a surface tessellation language file. Data were exported for 3D printing on a printer, and laminate veneers were printed in castable wax resin. Ceramic veneers were heat-pressed after investment according to the manufacturer's recommendations and further divided into three groups (n=10) according to luting cement type: (1) light-cure resin cement, (2) amine-free dual-cure resin cement, and (3) conventional dual-cure resin cement. Color measurements were performed from the middle of each specimen with a spectrophotometer before and after AAA for 300 hours with a total energy of 150 kJ/m2. Color changes were calculated with the CIEDE 2000 (ΔE00) formula. Color differences were assessed using two-way analysis of variance (ANOVA) (α=0.05), and the paired t-test was used to compare the L*, a*, and b* parameters in each group before and after aging. RESULTS: There were no significant differences between the ceramic groups (p>0.05). The color changes of the materials ranged from 2.26 to 3.13. All materials were above the clinically acceptable limit (ΔE00>1.8). The conventional dual-cure resin cement group showed more color change (p>0.05). CONCLUSIONS: Color changes were observed in all porcelain laminate veneers after artificial accelerated aging. The zirconia-reinforced lithium silicate veneers showed similar color changes as lithium disilicate veneers; the amine-free dual-cure resin cement showed a similar color change as light-cure resin cement after aging.

The effect of surface treatments on the adhesive bond in all-ceramic dental crowns using four-point bending and dynamic loading tests.

The aim of this study was to determine the effect of sandblasting, grinding and plasma treatment on the adhesive bond strength between framework ceramic (Y-TZP) and veneering ceramic (feldspar ceramic). Therefore, four-point bending specimens (n = 180) were cut from densely sintered 3Y-TZP blanks. Subsequently, 80 of these samples received surface treatment by sandblasting and 80 samples by grinding. A reference group (20 samples) was not processed. Half of the specimens that received a surface treatment were additionally exposed to an oxygen plasma treatment. After processing, all specimens were manually veneered with feldspar ceramic and examined with a four-point bending test to evaluate the strain energy release rate G. The surface treatment parameters that achieved the highest and lowest G were transferred to real geometries of a posterior crown (n = 45). The crowns' ceramic framework was sandblasted and veneered by hand. The all-ceramic crowns were tested in a dynamic loading test and Wöhler curves were evaluated. Four-point bending samples blasted at an angle of 90° at 6 bar and a working distance of 1.5 cm without plasma treatment achieved the highest energy release rate. Samples blasted at an angle of 90° at 2 bar and a working distance of 1 cm with plasma treatment achieved the lowest energy release rate. Overall, plasma treatment did not improve bond strength. In the dynamic loading test, the group blasted with 2 bar showed the best results.

Proof testing to improve the reliability and lifetime of ceramic dental prostheses.

OBJECTIVES: Ceramic dental prostheses exhibit increasing failure rates with service time. In particular, veneered crowns and bridges are susceptible to chipping and other fracture modes of failure. The purpose of this manuscript is to introduce a computational methodology and associated software that can predict the time-dependent probability of failure for ceramic prostheses and subsequently design proof test protocols to significantly enhance their reliabilities and lifetimes. METHODS: Transient reliability and corresponding proof testing theories are introduced. These theories are coded in the Ceramic Analysis and Reliability Evaluation of Structures (CARES/Life) code. This software will be used to demonstrate the predictive capability of the theory as well as its use in designing proof test protocols to significantly improve the reliability (survival probability) and lifetime for dental prostheses. A three-unit fixed dental prosthesis (FDP) with zirconia core (ZirCAD) and veneering ceramic (ZirPress) are used to compare the predicted probabilities of failure to general clinical results. In addition, the capability to use proof testing to significantly improve the performance (reliability and lifetime) for this restoration is demonstrated. RESULTS: The probability of failure, Pf, after five years without proof testing is predicted to be 0.337. This compares to clinical studies showing the failure rate to be between 0.2 and 0.23 after 5 years. After 10 years, reference 18 found the clinical failure rate for similar bridges (but not the same) to be up to 0.28 compared to the predicted Pf of 0.38. The difference may be due to the analysis applying the load at an inclination of 75° which is more critical than vertical loading. In addition, clinical studies often report a simple survival rate instead of using Kaplan-Meier analysis to properly account for late enrollees. Therefore, true clinical failure rates may be higher than reported and may more closely match the predictions of this manuscript. The effectiveness of proof testing increases with selecting materials less susceptible to slow crack growth (higher SCG exponent, N). For example, proof testing the ZirPress glass-veneered bridges with N = 43.4 analyzed in this manuscript at 400 N bite force for 1 s which induces a failure rate during proof testing of 0.31, reduces the Pf of bridges not proof tested from 0.45 to an attenuated-proof-tested probability of failure Pfa of 0.21 after 20 years of usage. If another material is selected with improved resistance to SCG of N = 60 and the same loading conditions, the failure rate for the proof tested bridges after 20 years of service drops to 2 in 10,000 from 2.4 in 100 had they been not proof tested. The failure rate during proof testing for this material would be 5.1 in 100. Proof testing a material with absolutely no susceptibility to SCG at the same service load (in this case 285 N, not even the 400 N load used above) results in 0 % failure rate and is of course independent of time. SIGNIFICANCE: The transient reliability and proof test theory presented in this paper and associated computational software CARES/Life were successful in predicting the performance of ceramic dental restorations when compared to clinical data. Well-designed proof test protocols combined with proper material selection can significantly enhance the reliabilities and lifetimes of ceramic prostheses. This proof test capability can be a translational technology if properly applied to dental restorations.

Stress distribution in occlusal veneers with different finish lines when applying vertical and tangential forces / Distribución de estrés en carillas con diferentes líneas de terminación aplicando fuerzas verticales y tangenciales

Abstract To evaluate stress distribution when applying vertical and tangential forces to 1mm thick occlusal veneers with different finish lines preparations, using the finite element method. One extracted third molar was prepared for occlusal veneers, firstly without any bevel. It was scanned in order to design two groups of lithium disilicate (G1A, G2A) and composite resin (G1B, G2B) occlusal veneers. Then, the third molar preparation was modified, beveling the finish line and it was subsequently scanned again to design the occlusal veneer groups with bevel (LD: G3A, G4A and CR: G3B, G4B). The four groups were subjected to different forces (400 N vertical and 900 N tangential). At 400 N, the non-beveled veneers showed slightly higher Von Mises stress values (G1A: 783 MPa and G1B 736.5 MPa) than the beveled veneers (G3A: 685.7 MPa and G3B: 675.8 MPa). However, when 900 N tangential forces were applied, the beveled occlusal veneers showed higher Von Mises stress values (G4A: 4297 MPa and G4B: 4133 MPa) than the non-beveled occlusal veneers (G2A: 2581.1 MPa and G2B: 3519.1 MPa). Furthermore, it was observed that the tissue under the occlusal veneers with bevel showed higher Von Mises stress values than the models without any bevel. Beveled and non-beveled occlusal veneers of lithium disilicate and composite resin presented similar stress distribution values when vertical forces of 400 N were applied; whereas with tangential forces of 900 N applied near to the finish line, the beveled groups presented notably higher stress values than the non-beveled groups. However, both finish line preparations presented adequate values for possible clinical performance.

Resumen Evaluar la distribución de estrés al aplicar fuerzas verticales y tangenciales en carillas oclusales de 1mm de espesor con diferentes líneas de terminación marginal por el método de elementos finitos. Se preparó un tercer molar extraído para carilla oclusal, primero sin bisel. Se escaneó para diseñar dos grupos de carillas oclusales de disilicato de litio (G1A, G2A) y resina compuesta (G1B, G2B). Después, esta preparación molar fue modificada, biselando la línea de terminación y escaneándola nuevamente para diseñar los grupos de carillas oclusales con bisel (DL: G3A, G4A and RC: G3B, G4B). Los 4 grupos fueron sometidos a fuerzas diferentes (400 N vertical y 900 N tangencial). Con 400 N, las carillas sin bisel presentaron ligera mayor tensión de Von Mises (G1A: 783 MPa y G1B 736.5 MPa) que las carillas con bisel (G3A: 685.7 MPa y G3B: 675.8 MPa). De distinta forma, al aplicar fuerzas tangenciales de 900 N, las carillas oclusales con bisel presentaron mayor tensión de Von Mises (G4A: 4297 MPa y G4B: 4133 MPa) que las carillas oclusales sin bisel (G2A: 2581.1 MPa y G2B: 3519.1 MPa). Además, se observó que los tejidos subyacentes a las carillas oclusales con bisel, presentaron mayor tensión de Von Mises, frente a los modelos sin bisel. Las carillas oclusales con y sin bisel de disilicato de litio y resina compuesta presentaron una distribución de estrés similar con fuerzas verticales de 400 N, por otro lado, con fuerzas tangenciales de 900 N, los grupos con bisel presentaron notablemente mayor tensión que los grupos sin bisel. Sin embargo, ambos diseños de terminación marginal presentaron valores adecuados para un posible desempeño clínico.

The efficiency of ErCr: YSGG laser on the debonding of different thicknesses of ceramic veneers

Aims: To verify the efficacy of Er,Cr:YSGG laser for debonding of lithium disilicate (LD) reinforced glass ceramic veneers of different thicknesses. Methods: Forty bovine teeth were prepared and randomly divided into four groups (n=10/group) according to the ceramic disc thickness: C0.5 (Control group) and L0.5 (Laser irradiated group) in which LD discs had a thickness of 0.5mm and 5mm diameter; C1 and L1 in which LD discs had a thickness of 1mm and 5mm diameter. The lithium disilcate discs (IPS E.max®, shade HTA2) were fabricated following the manufacturer's recommendations and cemented to the prepared tooth surface. The Er,Cr:YSGG laser was applied to the laser groups at 2.5W and 25Hz for 60seconds. Universal testing machine was used to evaluate the shear bond strength for all samples at a cross head speed of 1mm/min in an inciso-gingival direction parallel to the sample surface. After debonding, the samples were examined under stereoscope to evaluate the mode of failure according to the adhesive remnant index (ARI). Results: Laser irradiation significantly diminishes the shear bond strength from 10.868 MPa to 3.778 MPa for C0.5 and L0.5 groups respectively (p=0.00) and from 14.711 MPa to 4.992 MPa for C1 and L1 groups respectively (p=0.00). The shear bond strength required for debonding increased with increasing thickness of discs, but without significant difference (p=0.110). Higher ARI scores were seen in the laser groups (more cement remaining adhered to the tooth) when compared to the control groups. Conclusions: The Er,Cr:YSGG laser could be an effective and useful tool in debonding of lithium disilicate ceramic veneers as it decreases the shear bond strength required for veneer debonding

Computer-aided design expertise affects digital wax patterns of CAD/CAM laminate veneers more than single crowns.

AIM: There is controversy in the literature regarding clinical outcomes of CAD/CAM laminate veneers. The aim of the present study was to assess the impact of different levels of CAD expertise and different software programs on the reliability and reproducibility of digital wax patterns of laminate veneers and single crowns. MATERIALS AND METHODS: The present preliminary in vitro study was performed on 10 prepared maxillary central incisors available in dental study models. Of the total, five central incisors were prepared with shoulder finish lines for single crowns, whereas the other five underwent incisal shoulder preparation for laminate veneers. The models were scanned using an intraoral scanner. Four dentists (group DENT) and four CAD dental technicians (group CAD) with expertise in different software programs performed digital diagnostic waxing on all prepared teeth. The resulting digital wax patterns (n = 80) were exported as standard tessellation language (STL) files and superimposed on gold standard digital wax patterns (obtained from the original shape of the teeth before preparations). 3D mesh deviations at the cervical margins as well as distal, mesial, and incisal/palatal surfaces between each STL and the gold standard digital wax patterns were calculated in millimeters using a CAD software program. The mean time required by each operator to perform digital waxing was also recorded. Paired comparisons between groups DENT and CAD as well as between nondental and dental software programs were performed for the crowns and laminate veneers using the Wilcoxon signed-rank and paired t tests (α = 0.05). RESULTS: For group DENT, median deviations for single crowns were 0.15 mm (range: 0.08 to 1.05 mm) and for laminate veneers they were 0.15 mm (range: 0.08 to 0.76 mm). For group CAD, median deviations for single crowns were 0.16 mm (range: 0.09 to 0.73 mm) and for laminate veneers they were 0.10 mm (range: 0.06 to 0.53 mm). The Wilcoxon signed-rank test revealed a statistically significant difference between groups DENT and CAD (P = 0.041) and between the software programs (P = 0.029) for laminate veneers, but not for single crowns (P > 0.05). Furthermore, mean times required for group CAD and for dental software programs were significantly shorter than those for group DENT (P = 0.001) and for nondental software programs (P = 0.001), respectively. CONCLUSION: Within the limitations of the present study, the findings suggest that CAD expertise and the software program significantly affect digital wax patterns for laminate veneers, but not for single crowns. (Int J Comput Dent 2022;25(4):361-0; doi: 10.3290/j.ijcd.b3555819).

The effect of adding nanoparticles to dental porcelain on the fracture resistance and bond strength to zirconia core.

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.

Multidisciplinary approach for the closure of multiple diastemata with composite resin.

Morphologic anterior tooth alterations and diastemata between the anterior teeth are often considered a major esthetic problem. In most cases, the treatment of these conditions involves a multidisciplinary approach. Orthodontic treatment together with direct composite resin veneers are a viable option to close diastemata and alter tooth shape. The extent and etiology of the diastemata must be considered and properly evaluated for the treatment. The present article is a case report of a patient with multiple diastemata in the maxillary anterior teeth, dental crowding, and peg-shaped lateral incisors corrected with orthodontic treatment and direct composite resin veneers. Digital planning was the tool used to decide the tooth proportions before orthodontic treatment and to guide the diagnostic wax-up. An etch-and-rinse adhesive system was applied after etching. A polychromatic layering technique under rubber dam isolation was used for the composite resin veneer construction. Finishing and polishing procedures were achieved using polishing discs and abrasive materials. Direct composite resin is an alternative that allows predictability, esthetics, and the possibility of adjustments, resulting in patient satisfaction.

Shade management using a new zirconia-reinforced lithium disilicate press ceramic system and leucite-reinforced glass-ceramic veneering system.

The adhesive bonding technique together with tooth-colored ceramic material in fabricating veneers is considered one of the greatest achievements in modern prosthodontics. There is a wide range of indications for veneers, but they are most commonly used to establish adequate function and mask tooth discolorations and inappropriate tooth shape, size or position. A large variety of all-ceramic materials with excellent properties is available on the market today. It is challenging to select the material that will provide the best esthetics and function. The present article explains the principles of a modern, individual treatment approach for a young adult patient with multiple diastemata and shade disharmonies in the maxillary anterior teeth. The treatment plan was based on the selection of the appropriate ceramic material and technical procedures to achieve the best esthetic results using veneers. This included analyzing the specific case; defining the treatment goal; determining the precise shade; and selecting the most suitable and appropriate ceramic material, preparation design, fabrication technique, and adhesive concept. It was decided to use the new VITA zirconia-reinforced lithium disilicate press ceramic system and leucite-reinforced glass-ceramic veneering system to fabricate indirect ceramic veneers for all the maxillary anterior teeth. The size, shape, position, and shade of the natural teeth were changed and the diastemata were closed to achieve a more proportional dental relationship. The esthetic and functional goals were achieved and the patient was extremely satisfied with the final outcome.

Digital Veneering Techniques for Zirconia Implant-Supported Single Crowns-Bond Strength and Clinical Application.

PURPOSE: To evaluate the shear bond strength (SBS) of different digital veneering techniques for zirconia and to critically discuss its suitability for application in single-implant prosthetics. MATERIALS AND METHODS: A total of 112 square-shaped zirconia specimens were provided with four different veneering materials (n = 28 per group): a glass-ceramic (group GLA), a feldspathic ceramic (group FEL), a polymer-infiltrated ceramic network (group PIC), and a resin nanoceramic (group RNC). Discs in group GLA were sintered onto the core material, whereas all other specimens were adhesively connected. In each group, 14 specimens (GLA0, FEL0, PIC0, RNC0) were subjected to SBS testing before thermocycling, and the other 14 (GLA1, FEL1, PIC1, RNC1) were tested after thermocycling (10,000 cycles). Data were analyzed by applying SPSS software (P < .05). The surfaces and fracture patterns of the specimens were examined using scanning electron microscopy (SEM). RESULTS: Mean SBS values ranged from 14.09 ± 3.87 MPa (RNC1) to 40.82 ± 4.91 MPa (GLA0). Group GLA presented higher values than all other groups (P < .001). Groups FEL, PIC, and RNC showed no statistically significant differences between them. SBS decreased after thermocycling, but no significant impact was found. Every group exhibited a characteristic failure mode. CONCLUSION: All digital veneering techniques sufficed to present clinically acceptable SBS values and might be viable alternatives in implant prosthetics. However, some have yet to demonstrate their long-term clinical suitability. At present, lithium disilicate-veneered zirconia abutments and monolithic lithium disilicate hybrid abutment crowns seem to present a proven and reliable restorative option.

Digital image analysis of fluorescence of ceramic veneers with different ceramic materials and resin cements.

The objective of this study was to analyze the effect of the type of ceramics and resin cements on the fluorescence of ceramic veneers under the 405 nm UV-light by digital imaging. One hundred and ninety-two veneers were fabricated using three types of ceramics (IPS e.max CAD, IPS Empress CAD, and Zenostar). Eight pieces of substrates were made of resin-nano-ceramic (Lava Ultimate). The level of fluorescence for each sample cemented with the substrate using three kinds of resin cements (RelyX U200, Variolink N, and Choice 2) was analyzed by using histogram data of luminosity from Adobe Photoshop software. Furthermore, the fluorescence values were evaluated by two-way ANOVA and Tukey's test. The highest fluorescence values were observed for the IPS e.max CAD cemented with Choice 2 cement, followed by IPS Empress CAD, and Zenostar the lowest. The final fluorescence intensity of ceramic veneer is affected by ceramic materials and resin cements.

Obturator-cum-gingival Veneer.

Null.

No-Prep semidirect composite resin veneer. A Step-by-Step case report in a deciduous canine with a one-year follow-Up / Carilla de resina semidirecta sin preparación. Un reporte paso a paso en un canino deciduo con seguimiento de un año

Abstract The presence of deciduous canines in adulthood may be of aesthetic concern for patients. Many clinical alternatives include surgical and orthodontic treatment. Since patients search for highly esthetic results and more conservative alternatives, the present clinical report describes a treatment for deciduous canine through an indirect composite resin veneer and an indirect composite resin fragment restoration in a premolar to improve esthetic outcomes with a one-year follow up.

Resumen La presencia de caninos deciduos en adultos puede ser de preocupación estética por parte de los pacientes. Diversas alternativas clínicas pueden incluir tratamientos quirúrgicos y ortodóncicos. Desde que los pacientes buscan por resultados de alta estética y cada vez más conservadores, es que el presente caso clínico describe el tratamiento de un canino deciduo mediante una carilla indirecta de resina compuesta junto a un fragmento indirecto de resina de un premolar con el fin de mejorar los resultados estéticos, y con un año de seguimiento.

Restabelecimento estético de incisivos laterais conóides e amplas restaurações em resina composta com laminados cerâmicos: relato de caso / Aesthetic recovering of conoid side incisives and wide restoration in composed resin with ceramic laminates: case report

Introdução: As cerâmicas odontológicas são amplamente utilizadas na Odontologia, desfrutando de grande popularidade devido a sua capacidade de mimetizar as características ópticas do esmalte e da dentina. O constante desenvolvimento de pesquisas tem desencadeado o lançamento de novos sistemas cerâmicos com propriedades aprimoradas e melhores resultados clínicos em longo prazo. Objetivo: O relato de caso aqui apresentado descreve uma reabilitação da zona estética do sorriso com laminados cerâmicos por meio de uma abordagem minimamente invasiva. Relato de caso: Paciente do gênero feminino, compareceu à clínica odontológica relatando insatisfação com a aparência do seu sorriso. Durante avaliação foram observadas, na região anterossuperior, restaurações extensas em resina composta deficientes nos incisivos, com proporção, volume, forma e texturização insatisfatórias, que em conjunto comprometia a zona estética do sorriso. Diante disso, após fotografias extra e intraorais, o tratamento proposto foi a reabilitação com laminados cerâmicos nas unidades 1.2 ao 2.2. Assim, foi realizado o enceramento e o mock-up, os quais serviram de orientação para os preparos dentários, a seguir, foram moldados e as restaurações confeccionadas no sistema IPS e.max. Após prova de cor e adaptação, os preparos e a superfície interna dos laminados cerâmicos foram tratados e cimentados com cimento resino fotopolimerizável. Conclusão: Instituindo uma abordagem conservadora, o plano de tratamento realizado através da reabilitação com laminados cerâmicos nas unidades dentárias anterossuperiores, permitiu o restabelecimento da função e estética, com reprodução das características dos dentes naturais e promoção do equilíbrio, da jovialidade e da harmonia no sorriso(AU)

Introduction: Dental ceramics are widely used in dentistry, enjoying great popularity due to the ability to mimic both enamel and dentin optical characteristics. The constant research development has triggered the launch of new ceramic systems with improved properties and better long-term clinical results. Objective: The case report presented here describes the zone rehabilitation of the aesthetic smile with ceramic laminates through a minimally invasive approach. Case report: Female patient, attended the dental clinic reporting dissatisfaction with the appearance of her smile. During the evaluation, extensive restorations in composite resin were observed in the incisors in the anterosuperior region, with unsatisfactory proportion, amount, shape and texturing, which together compromised the aesthetic zone of the smile. Faced with this, after extra and intraoral photographs, the proposed treatment was the restoration with the ceramic laminates in units 1.2 to 2.2. Thus, waxing and mock-up were performed, which served as guidance for the dental preparations, then they were molded and restorations fabricated in the IPS e.max system. After shade and adaptation proof, the preparations and the inner ceramic laminates surface were treated and cemented with light-cured resin cement. Conclusion: Adopting a conservative approach, the treatment plan carried out through restoration with ceramic laminates on the upper anterior teeth allowed the recovering function and aesthetics, reproducing characteristics of natural teeth and promoting balance, joviality and harmony in the smile(AU)

Ultrathin CAD-CAM glass-ceramic and composite resin occlusal veneers for the treatment of severe dental erosion: An up to 3-year randomized clinical trial.

STATEMENT OF PROBLEM: Ultrathin bonded posterior occlusal veneers represent a conservative alternative to traditional onlays and complete coverage crowns for the treatment of erosive dental wear. Data regarding the clinical performance of ceramic and composite resin ultrathin occlusal veneers are lacking. PURPOSE: The purpose of this prospective randomized clinical trial was to evaluate the influence of computer-aided design and computer-aided manufacturing (CAD-CAM) restorative material (ceramic versus composite resin) on the clinical performance of ultrathin occlusal veneers bonded to worn posterior teeth. MATERIAL AND METHODS: Eleven participants (mean age, 30.4 years) had their posterior teeth restored with 24 ceramic (e.max CAD) and 36 composite resin (Lava Ultimate) ultrathin occlusal veneers. The material type was assigned randomly. The tooth preparations were trial restoration driven and included immediate dentin sealing (OptiBond FL). The intaglio surfaces of the ceramic restorations were etched with hydrofluoric acid and silanated, and the composite resins were airborne-particle abraded and silanated. The tooth preparations were airborne-particle abraded and etched with phosphoric acid before restoration insertion. All restorations were adhesively luted with preheated composite resin (Filtek Z100). The participants were evaluated according to the modified United States Public Health Service (USPHS) criteria at baseline and then each year for up to 3 years. Survival rates were estimated with time to failure (primary outcome of interest) as the endpoint (scores 4 or 5). RESULTS: No restorations were lost. Five partial failures, in the form of chipping (all scored 4), were observed in the composite resin group (Lava Ultimate). The Kaplan-Meier survival rates were 100% for ceramic and 84.7% (SE 0.065%) for composite resin. Differences between the 2 groups were not statistically significant (P=.124). In the surviving restorations, significant difference (P=.003) was found for surface roughness as restorations in the composite resin group experienced some surface degradation. CONCLUSIONS: The findings of this medium-term clinical trial suggest that ceramic (e.max CAD) and composite resin (Lava Ultimate) CAD-CAM ultrathin occlusal veneers presented statistically comparable performance regardless of the minor partial failures (restorable chipping) observed in the composite resin group. Higher surface degradation was observed in the composite resin group.

Evaluation of color change before and after polymerization of laminate veneer restorations: A clinical study.

Background and Aim: The purpose of this in vivo study was to investigate the effect of translucent adhesive resin cement on the final color of ceramic laminate veneer restoration before and after polymerization in intraoral conditions. Materials and Methods: This study was conducted in 92 ceramic laminate veneer restorations of 27 patients. The ceramic laminate veneer restorations in standard thickness lithium disilicate ceramic structure (IPS e.max Press HT, Ivoclar Vivadent) were cemented to the tooth with translucent light-polymerized resin cement (Choice 2 Starter Kit, Bisco). Results: It was observed a clinically noticeable color change between ΔE values before and after polymerization (ΔE >3.3). There was a statistically significant difference in b* values, ΔL value, and Δb value. Conclusion: Within the limitations of this in vivo study, the results suggest that light polymerization of the translucent resin cement (Choice 2, Bisco) used is an important factor for the final color of the restoration and should be considered during shade selection and fabrication.

Accelerated artificial aging and color stability in resin-based cements.

The aim of this study was to determine color change after accelerated artificial ageing (AAA) of different composite cements that are used with veneers. Five cylindrical test specimens, 15 mm in diameter and 2 mm thick, were made from a single layer of each of the following: RelyX Veneer 3M ESPE (RX), Paracore White Coltene (PC), Solocem White Opaque Coltene (SO), Resin Duo Cement Densell (DC), Panavia V5 Paste Kuraray Noritake (PA) and Panavia F2.0 Kuraray Noritake (PF) (30 specimens altogether). The specimens were light cured following manufacturers' instructions using a Coltolux LED (Coltene) unit. Initial color was determined using an Easyshade - Vita Zahnfabrik Spectrophotometer. Then, the specimens were subjected to AAA for two weeks (336 hours) with cycles of 4 hours of UV light at 60 °C and 4 hours of vapor condensation at 50 °C, successively, after which color was recorded again. Color change was determined for each specimen according to the differenceinshadeon the Vita scale before and after AAA. Results were analyzed using Kruskal Wallis test. Mean and standard deviation for each group were: RX 8.40 (1.52); PC 8.60 (3.13); SO 6.40 (3.51); DC 10.00 (0.00); PA 7.60 (3.29); PF 2.00 (0.00). The Kruskal Wallis test showed significant difference for material (p<0.05), and comparison of means showed difference between Panavia F2.0 and the other materials. A table providing equivalence between the Vita Classic and CIELAB scales was used to transfer the recorded colors to the CIELAB scale, and the color difference ΔE was calculated for each group, where ΔL, Δa and Δb are the differences in the L, a and b values before and after the AAA. The mean and standard deviation were analyzed statistically by the ANOVA test and Tukey's test. Mean and standard deviation for each group were: RX 14.94 (2.02); PC 14.51 (4.02); SO 12.08 (4.53); DC 16.31 (0.00); PA 10.9 (3.38); PF 7.24 (0.00). The ANOVA test showed significantdifferenceformaterial (p<0.05). Tukey's test showed two groups (PF-DC, RX, PA). Under the experimental conditions of this study, it can be concluded that accelerated ageing significantly affects the color stability of the resin based cements tested.

El objetivo de este trabajo fue determinar el cambio de coloración de distintos medios de fijación a base de resinas con indicación para carillas estéticas luego de someterse al envejecimiento artificial acelerado (AAA). Se confeccionaron 30 probetas cilíndricas de 15 mm de diámetro y 2 mm de espesor con RelyX Veneer 3M ESPE (RX), Paracore White Coltene (PC), Solocem White Opaque Coltene (SO), Resin Duo Cement Densell (DC), Panavia V5 Paste Kuraray Noritake (PA) y Panavia F2.0 Kuraray Noritake (PF) de una sola capa de material. Se polimerizaron según las indicaciones del fabricante con unidad de curado Coltolux LED (Coltene). Cada grupo quedó conformado con 5 probetas de cada material. Se tomó el color con el espectrofotómetro Easyshade de Vita Zahnfabrik. A continuación, se sometieron a AAA por dos semanas (336 horas) con ciclos de 4 horas de radiaciones ultravioletas a 60°C Y 4 horas de condensación de vapor de agua a 50°C sucesivamente. Unavezterminado esteproceso se volvió a registrar el color. El cambio de color se evaluó dentro de la escala de color, ordenada en función del valor. El dato registrado fue la diferencia en la posición inicial y final en esta escala. Los resultados obtenidos para cada grupo fueron analizados por medio de la prueba de Kruskal Wallis. Los valores de media y desvío estándar de cada grupo fueron: RX 8,40 (1,52); PC 8,60 (3,13); SO 6,40 (3,51); DC 10,00 (0,00); PA 7,60 (3,29); PF 2,00 (0,00). El análisis con la prueba de Kruskal Wallis mostró diferencia significativa para el factor material (p<0.05) y la comparación de medias mostró diferencia entre PF y el resto de los materiales. Por otra parte, con una tabla de equivalencia entre los colores en escala de Vita Classic y CIE Lab, se hicieron el pasaje de los valores registrados a la escala de CIE Lab y se calculó la diferencia de color ΔE de cada grupo antes y después del AAA. La media y el desvío estándarfueronanalizadosestadísticamente por el test de ANOVA y prueba de Tukey. Los valores de media y desvío estándar de cada grupo fueron: RX 14,94 (2,02); PC 14,51 (4,02); SO 12,08 (4,53); DC 16,31 (0,00); PA 10,9 (3,38); PF 7,24 (0,00). En la evaluación de los resultados con ANOVA se encontró diferencia significativa entre los materiales evaluados (p<0,05). La comparación de medias con prueba de Tukey mostró la presencia de dos grupos (PF-DC, RX, PA). En las condiciones experimentales de este trabajo puede concluirse que el envejecimiento acelerado afecta significativamente la estabilidad de color de los cementos utilizados en este trabajo.

A retrospective clinical study of fixed tooth- and implant-supported prostheses in titanium and cobalt-chromium-ceramic: 5-9-year follow-up.

OBJECTIVES: The aim of this retrospective study was to evaluate the clinical outcome of fixed tooth- and implant-supported protheses manufactured in porcelain veneered cobalt-chromium (CoCr) or titanium with a follow-up period of 5-9 years. MATERIALS AND METHODS: This study included 63 patients with a total of 86 fixed dental protheses (FDPs) (53 implant-supported and 33 tooth-supported). In total, 67 were short-span FDPs (3-5 units) and 19 were long-span FDPs (6-12 units). The FDPs were evaluated using a modified version of the California Dental Association (CDA). RESULTS: The binary regression analysis indicated that neither CoCr nor titanium had a statistically significant effect on the odds of success or survival of either tooth- or implant-supported FDPs. However, the success of FDPs was negatively affected by greater FDP length and general tooth wear. The survival of FDPs was negatively affected by increased FDP longevity. CONCLUSIONS: This study found no statistically significant effect on the odds of success and survival outcomes for any combination of tooth-supported, implant-supported, porcelain-veneered CoCr, or porcelain-veneered titanium FDPs. As the number of FDPs was limited, the results should be interpreted with caution. CLINICAL RELEVANCE: This study shows that the choice between CoCr porcelain and titanium porcelain in fixed protheses did not have a statistically significant effect on the outcome.