1.The removal of three kinds of occlusal veneers by Er: Yag laser.
Jianyu ZHU ; Feifei HONG ; Lianghang HE ; Wei WEN ; Xianlin LEI ; Zhisheng ZHANG ; Lu YIN
West China Journal of Stomatology 2023;41(5):568-572
OBJECTIVES:
This study aimed to remove occlusal veneers of varied thicknesses and compositions by Er:Yag laser in vitro and analyze the interfacial microstructure between veneers and tooth that irradiated by laser, by which experimental evidence could be provided to support the non-invasive removal of occlusal veneerby laser.
METHODS:
Fresh mandibular premolars extracted for orthodontic requirements were collected for tooth preparation. Three kinds of ceramic materials (Vita Suprinity, Vita Mark Ⅱ, and Upcera Hyramic) were selected to fabricate occlusal veneer with different thicknesses (1.0, 1.5, and 2.0 mm). One week later, Er:Yag laser (2.5 W and 3.5 W) was used to irradiate and remove the occlusal veneer and recorded the timespan. After the removal operation, the micro-morphologies of samples were examined by scanning electron microscope.
RESULTS:
Upcera Hyramic veneer failed to be removed (>20 min); the operation span at 2.5 W, Vita Suprinity (96.0 s±16.0 s) was longer than Vita MarkⅡ(84.5 s±19.5 s) in the 1.0 mm group (P<0.05), and Vita Suprinity (246.5 s±13.5 s) was longer than Vita MarkⅡ(170.0 s±14.0 s) in the 1.5 mm group (P<0.05). At 3.5 W, Vita Suprinity (381.0 s±24.0 s) was longer than Vita MarkⅡ(341.5 s±26.5 s) in the 2.0 mm group.
CONCLUSIONS
Increasing laser power could shorten the operation span and facilitate the removal of occlusal veneers with the same thickness and composition. The occlusal veneer was sustained when insufficient laser power was applied. With the same laser power and ceramic thickness, laser penetration could interfere with the integral of the ceramic structure when the laser interacted with the bonding layer. With the same ceramic composition and laser power, the operation span and laser power increased with the thickness of the occlusal veneer. However, the laser was incapable of removing occlusal resin veneer directly.
Lasers, Solid-State
;
Materials Testing
;
Dental Porcelain/chemistry*
;
Ceramics/chemistry*
;
Bicuspid
;
Dental Veneers
2.Marginal features of CAD/CAM laminate veneers with different materials and thicknesses.
Yi LI ; Lai U WONG ; Xiao Qiang LIU ; Ti ZHOU ; Ji Zhe LYU ; Jian Guo TAN
Journal of Peking University(Health Sciences) 2022;54(1):140-145
OBJECTIVE:
To analyze the marginal roughness and marginal fitness of chairside computer-aided design and computer-aided manufacturing (CAD/CAM) laminate veneers with different materials and thicknesses, and to provide a reference for the clinical application of laminate veneers.
METHODS:
The butt-to-butt type laminate veneers were prepared on resin typodonts, the preparations were scanned, and the laminate veneers were manufactured by chairside CAD/CAM equipment. The laminate veneers were divided into four groups (n=9) according to the materials (glass-matrix ceramics and resin-matrix ceramics) and thickness (0.3 mm and 0.5 mm) of the veneers, with a total of 36. The marginal topo-graphies of each laminate veneer were digitally recorded by stereomicroscope, and the marginal rough-nesses of the laminate veneers were determined by ImageJ software. The marginal fitness of the laminate veneers was measured by a fit checker and digital scanning and measuring method. At the same time, the mechanical properties of glass-matrix ceramic and resin-matrix ceramic bars (n=20) were tested by a universal testing device.
RESULTS:
The marginal roughness of 0.3 mm and 0.5 mm glass-matrix ceramic laminate veneers was (24.48±5.55) μm and (19.06±5.75) μm, respectively, with a statistically significant difference (P < 0.001). The marginal roughness of 0.3 mm and 0.5 mm resin-matrix ceramic laminate veneers was (6.13±1.27) μm and (6.84±2.19) μm, respectively, without a statistically significant difference (P>0.05). The marginal roughness of the glass-matrix ceramic laminate veneers was higher than that of the resin-matrix ceramic laminate veneers with a statistically significant difference (P < 0.001). The marginal fitness of 0.3 mm and 0.5 mm glass-matrix ceramic laminate veneers were (66.30±26.71) μm and (85.48±30.44) μm, respectively. The marginal fitness of 0.3 mm and 0.5 mm resin-matrix ceramic laminate veneers were (56.42±19.27) μm and (58.36±8.33) μm, respectively. There was no statistically significant difference among the 4 groups (P>0.05). For glass-matrix ceramics, the flexural strength was (327.40±54.25) MPa, the flexural modulus was (44.40±4.39) GPa, and the modulus of resilience was (1.24±0.37) MPa. For resin-matrix ceramics, the flexural strength was (173.71±16.61) MPa, the flexural modulus was (11.88±0.51) GPa, and the modulus of resilience was (1.29±0.27) MPa. The flexural strength and modulus of glass-matrix ceramics were significantly higher than those of resin-matrix ceramics (P < 0.001), but there was no statistically significant difference in the modulus of resilience between the two materials (P>0.05).
CONCLUSION
The marginal roughness of CAD/CAM glass-matrix ceramic laminate veneers is greater than that of resin-matrix ceramic laminate veneers, but there was no statistically significant difference in marginal fitness among them. Increasing the thickness can reduce the marginal roughness of glass-matrix ceramic laminate veneers, but has no effect on the marginal roughness of resin-matrix ceramic laminate veneers.
Ceramics
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Computer-Aided Design
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Dental Porcelain
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Dental Veneers
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Materials Testing
;
Surface Properties
3.Expert consensus on porcelain veneer technology in oral esthetic restoration.
Chinese Journal of Stomatology 2021;56(12):1185-1190
In recent years, porcelain veneer restoration has been widely carried out in clinical practice. In order to standardize the clinical behavior, Chinese Society of Esthetic Dentistry organized experts in relevant fields to formulate an expert consensus on porcelain veneer technology in oral esthetic restoration. The consensus described in detail the material selection, clinical indications, tooth preparation requirements and bonding process of porcelain veneer restoration. It puts forward expert suggestions on how to obtain the strong and durable porcelain veneer restoration effect, prevent complications, and provide patients with comfortable diagnosis and treatment experience. At the same time, in order to provide reference for making successful porcelain veneer restoration in line with the connotation of oral esthetics, Chinese Society of Esthetic Dentistry put forward with its own characteristics the concept of taking esthetic design as the guidance, emphasizing the combination of local and overall esthetics, and carrying out multi-disciplinary porcelain veneer restoration.
Consensus
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Dental Porcelain
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Dental Veneers
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Esthetics, Dental
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Humans
;
Technology
4.A randomized controlled study on color stability of tetracycline teeth restored with ceramic veneer.
West China Journal of Stomatology 2021;39(3):336-340
OBJECTIVES:
This study aimed to evaluate the color stability of tetracycline teeth restored with ceramic veneers of different thicknesses combined with different resin cement systems after aging.
METHODS:
Twenty patients with tetracycline teeth, including two maxillary central incisors, were selected clinically. The patients were randomly divided into four groups and restored with 0.5 and 0.75 mm ceramic veneers by using a veneer adhesive system, either with light-cured or dual-cured reaction. The color difference (ΔE) values after cementation and 1, 6, 12, and 24 months of use were obtained by quantification of L*, a*, and b* values with a colorimeter. The results were analyzed statistically with two-way ANOVA and Student's
RESULTS:
The ΔE values of ceramic veneers detected after aging were less than 2.25. The 0.5 mm groups exhibited greater color change than the 0.75 mm-thick veneers (
CONCLUSIONS
Resin cements and veneer thickness influence the color of ceramic veneers after aging. Cementation of veneers with either dual- or light-cured resin cements does not affect the long-term color stability of tetracycline teeth differently.
Ceramics
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Color
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Dental Porcelain
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Dental Veneers
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Humans
;
Materials Testing
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Resin Cements
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Tetracyclines
5.Effect of ceramic materials on the optical properties of porcelain veneers for tetracycline-stained teeth.
Jin CHEN ; Qi XIA ; Ling-Ling ZHANG ; Hui-Fen QIAN ; Xing-Xing LI
West China Journal of Stomatology 2021;39(3):341-346
OBJECTIVES:
To analyze the chromatic properties and translucency of porcelain veneers made from different ceramic materials against the background of tetracycline-stained teeth.
METHODS:
Porcelain specimens (A1, A3, B2, B4) measuring 0.50 mm in thickness were prepared by heat-press casting and layering. The L*, a*, and b* values of the specimens against simulated tetracycline tooth and black-and-white backgrounds were measured by a spectrophotometer, and color differences ΔE
RESULTS:
The ΔE
CONCLUSIONS
When changing the color of tetracycline-stained teeth, 0.50 mm-thick IPS d.SIGN feldspathic veneers with an opaque layer provide better chromatic properties than IPS e.max Press LT glass ceramic veneers. However, the translucency of feldspathic veneers is generally poorer than that of glass ceramic veneers.
Ceramics
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Color
;
Dental Porcelain
;
Dental Veneers
;
Materials Testing
;
Tetracyclines
6.Challenges in Managing a Fractured Cement retained Crown Located at the Aesthetic Zone: A Case Report
Oon Take Yeoh ; Wei Cheong Ngeow
Archives of Orofacial Sciences 2021;16(1):69-75
ABSTRACT
Implant prosthesis is a popular treatment modality but it is not complication free. This article discussed
the management of a cemented, all-ceramic implant crown in the maxillary anterior region that had
veneering ceramic fracture after three years in function. A screw-retained prosthesis was prescribed
to avoid the show of the screw access channel on the incisal edge of the crown. This was achieved by
changing the location of the screw hole using the angle screw channel that overcame the angulation issue.
Dental Veneers
7.Operational specifications for the cementation of porcelain laminate veneers.
Chinese Journal of Stomatology 2020;55(6):373-377
The minimal tooth reduction, esthetic appeal and biocompatibility of porcelain laminate veneers have made them one of the mainstream technologies for minimal invasive esthetic dental restorations. Cementation is a crucial step in ensuring retention, marginal seal and influencing the clinical longevity of veneer restorations. Experts from Society of Prosthodontics, Chinese Stomatological Association formulated operational specifications for the cementation of porcelain laminate veneers, so as to standardize the clinical operating procedures, achieve the long-term success of veneer restorations, and promote the application of porcelain laminate veneers.
Cementation
;
Dental Porcelain
;
Dental Veneers
;
Esthetics, Dental
8.Color changes of ceramic veneers following glazing with respect to their composition
Sung Joon KIM ; Jae Man WOO ; Chan Woo JO ; Ju Hee PARK ; Soo Kyung KIM ; Se Hoon KAHM
The Journal of Advanced Prosthodontics 2019;11(1):16-22
PURPOSE: The purpose of this study was to compare the translucency and color changes of ceramic laminate veneers of different composition following glazing process. MATERIALS AND METHODS: 10 mm × 10 mm square specimens of 0.6 mm and 1.0 mm thicknesses were fabricated with IPS e.max Press (EM) and IPS e.max ZirPress (ZP) (n=10 per group). The color coordinates (CIE L* a* b*) of the specimens were recorded with a colorimeter before and after glazing. The color changes and translucency parameter (TP) were calculated. For the comparisons with the composition and thicknesses between the ‘not glazed’ and ‘glazed’ groups, statistical analyses were done through paired T-test, independent two-sample T-test, and multiple regression analysis using SPSS 18.0 (P < .05). RESULTS: The TP of 0.6 mm EM was higher than that of 0.6 mm ZP. Total color difference (ΔE*) between bare and glazed specimens of 1.0 mm EM was greater than that of 1.0 mm ZP with statistical significance. Following glazing, specimens from all groups showed statistically significant amount of decrease in L* and a*, and statistically significant increase in b*. The result of multiple regression analysis of EM and ZP showed that ΔL* improved ΔE*. CONCLUSION: Within the limitations of present study, we conclude that translucency and color of ceramic laminate veneers change significantly after glazing process, and the nature and amount of changes vary with different compositions.
Ceramics
;
Dental Veneers
9.Effect of different surface zirconium oxide treatments on binding strength between zirconia and veneering ceramics.
Yuhong XIA ; Fei XU ; Lei CHEN ; Xiongwen ZHOU ; Yang CAO ; Hui TONG
Journal of Central South University(Medical Sciences) 2019;44(1):53-58
To compare the effect of three different surface zirconium oxide treatments on binding strength and fracture patterns between zirconia and veneering ceramics.
Methods: A total of 40 zirconia specimens and 10 nickel-chromium alloy were divided into 5 groups (n=10 in each group): a treatment group by zirconium oxide sand-blaste (Group A), a zirconia bonded porcelain group (Group B), a hot-etching solution group (Group C), a non-treatment zirconia (Group D) and a non-treatment nickel-chromium alloy group (Group E). After all treatments, a veneering porcelain (4 mm×4 mm×2 mm) was formed onto the center of all substrate specimens by plastic coating method. Shear bond strength (SBS) test with a universal testing machine was used in each group. Scanning electron microscopy was used to observe the surface morphology of the damaged specimen interface, which was randomly selected from each group.
Results: The SBS test showed that there was no significant difference in SBS results between the Group A, the Group B and the Group D (both P>0.05), and both of them were significant less than that in the group E (both P<0.05). The SBS results in the Group C were significantly higher than that in the Group D, the Group A, and the Group B (all P<0.05), but there were no significant difference compared with that in the Group E (P<0.05).
Conclusion: Sand-blaste and liner application on zirconia ceramic contribute no effect to binding strength between zirconia and veneering ceramics, but hot-etching solution can increase the binding strength between zirconia and veneering ceramics.
Ceramics
;
Dental Bonding
;
Dental Stress Analysis
;
Dental Veneers
;
Materials Testing
;
Microscopy, Electron, Scanning
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Shear Strength
;
Stress, Mechanical
;
Surface Properties
;
Zirconium
10.In vivo optical coherence tomographic imaging to monitor gingival recovery and the adhesive interface in aesthetic oral rehabilitation: A case report
Nathalia Del Rio Lyra GRAÇA ; Anna Rebeca de Barros Lins Silva PALMEIRA ; Luana Osório FERNANDES ; Marlus da Silva PEDROSA ; Renata Pedrosa GUIMARÃES ; Saulo Cabral DOS SANTOS ; Anderson Stevens Leonidas GOMES ; Claudio Heliomar Vicente DA SILVA
Imaging Science in Dentistry 2019;49(2):171-176
The available methods for veneer evaluation are limited to clinical and radiographic examinations, which may not allow the appropriate identification of failure. In this report, we demonstrate the use of optical coherence tomography (OCT) as a noninvasive diagnostic and follow-up method to evaluate gingival recovery and the adhesive interface in aesthetic oral rehabilitation involving periodontal plastic surgery and ceramic laminate veneers. OCT was efficient for evaluating both soft and hard tissues, as well as the quality of the adhesive interface. In conclusion, OCT was found to be a promising approach for the professional evaluation of aesthetic oral rehabilitation, as it was capable of generating images that enabled the analysis of gingival recovery and the adhesive interface.
Adhesives
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Ceramics
;
Dental Bonding
;
Dental Veneers
;
Esthetics, Dental
;
Follow-Up Studies
;
Gingivectomy
;
Methods
;
Rehabilitation
;
Surgery, Plastic
;
Tomography, Optical Coherence


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