Effect of incisal preparation design on load‐to‐failure of ceramic veneers (original) (raw)
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Incisal preparation design for ceramic veneers
The Journal of the American Dental Association, 2018
Background. The authors reviewed and identified the evidence for the various incisal preparation designs for ceramic veneers. Types of Studies Reviewed. The authors searched MEDLINE with PubMed and Ovid to identify any articles in the English language related to the topic up through March 2017 using a combination of key words: "porcelain veneer or ceramic veneer or dental veneer or labial veneer" AND "preparation," NOT "composite veneer," NOT "crown," NOT "implant," NOT "fixed partial denture or bridge or denture," NOT "porcelain-fused-to-metal," NOT "marginal gap or fit." Results. In vitro studies showed that the palatal chamfer preparation design increases the risk of developing ceramic fractures. The butt joint preparation design had the least effect on the strength of the tooth. Conclusions. Surveys show the 2 most common incisal preparation designs provided are butt joint and feathered-edge. Clinical studies have identified that incisal ceramic is the most common location of ceramic fracture. In addition, there is a lack in standardization of the modeling structures and type of finite element analysis. Practical Implications. The evidence seems to support the use of butt joint over palatal chamfer incisal preparation design. Fracture or chipping is the most frequent complication and the risk increases with time. Incisal ceramic is the most common location of ceramic fracture.
Brazilian Dental Science, 2021
Objective: Evaluate the effect of four preparation designs, two ceramic materials, and two occlusion contact types on the stress distribution of ceramic veneer in upper central incisor. Material and methods: 3D-models were performed in the modeling software containing enamel, dentin, pulp, periodontal ligament and a base of polyurethane resin. The designs were modeled and exported to the computer aided engineering software to perform the static structural analysis. For the mesh, a total of 155429 tetrahedron elements and 271683 nodes were used, after a 10% convergence test. Two materials, lithium disilicate and feldspathic ceramics, were simulated. A static load of 100 N on 45º was applied on the incisal and middle thirds of the palatal tooth region, guided by the occlusal plane. The base was constrained in all directions. The Maximum Principal Stress was the failure criteria chosen for the analysis. Results: The Finite Element Analysis showed that the most conservative designs pre...
Relation between fracture load and tooth preparation of ceramic veneers
Health sciences, 2013
Fracture is the major clinical failure modality of ceramic veneers. Effect of tooth preparation on the strength of ceramic veneers still remains a controversial issue. Purpose of the study: Our in-vitro study was aimed at exploring the possible association between tooth preparation and strength of ceramic veneers. Materials and Methods: Forty extracted human central incisors were divided into four groups. First group was given ‘feather edge design’. ‘Butt joint’ and palatal chamfer’ designs were given for the other two groups. Fourth group was the control. Epoxy resin was used as the mounting medium. Teeth were prepared, veneers were made and cemented. Vertical force was applied until fracture was noted. Failure load and mode of failure were analyzed. Result and conclusion: Statistical analysis revealed that veneers prepared in teeth with ‘feather edge’ preparation design were the strongest followed by teeth with ‘incisal butt joint’ and ‘palatal chamfer’ designs. But in situations which demands incisal reduction, ‘incisal butt joint’ design was the design of choice
Fracture Resistance of Ceramic Veneers with Different Preparation Designs
Journal of Prosthodontics, 2011
Purpose: The purpose of this study was to examine the fracture load of ceramic veneers with different preparation designs. Materials and Methods: Seventy-five extracted, intact, human maxillary central incisors were prepared according to five preparation designs (P) (n: 15) as follows: (1) P2e: 2-mm incisal reduction, preparation entirely in enamel; (2) P4e: 4-mm incisal reduction, preparation entirely in enamel; (3) P2d: 2-mm incisal reduction, preparation entirely in dentin; (4) P4d: 4-mm incisal reduction, preparation entirely in dentin; and (6) Pc: Unrestored, intact teeth as control. All preparations had a butt joint incisal finish line, rounded internal line angles, and cervical finish lines 1 mm above the cementoenamel junction. Ceramic veneers were fabricated with IPS Empress (Ivoclar Vivadent AG, Schaan, Liechtenstein) and cemented with Syntac Classic Adhesive system and Variolink II (Ivoclar) resin cement. Veneers were loaded until fracture at a 90 • angle to the lingual surface of the test tooth following the thermocycling process (5 • to 55 • , 3500 times). Statistical analyses were performed using analysis of variance (ANOVA) and Tukey's Multiple Range Test. Results: The mean fracture loads (SD) were (in N) as follows: (1) P2e: 262 (63); (2) P4e: 189 (40); (3) P2d: 239 (53); (4) P4d: 162 (36); and (5) Pc: 277 (66). The amount of incisal reduction exhibited a significant influence on fracture resistance regardless of the preparation depth (p < 0.05). Conclusions: Ceramic veneers with preparation designs entirely on dentin with 4-mm incisal reduction yielded lower fracture loads than those prepared with 2-mm incisal reduction. Veneers with 2-mm incisal reduction exhibited fracture resistance similar to that of intact teeth for preparation designs supplied on both enamel and dentin.
Indian J Dent Sci , 2021
Background: Ceramic veneers is one of the conservative esthetic treatment modality in dentistry. Success of veneer is very much dependent on the design preparation. Materials and Methods: Thirty selected teeth were categorized within three groups of 10 each with varying design preparations. After mounting the specimens, the incisal reduction was done, and porcelain laminate veneers were fabricated. Then cementation of the veneers was done with resin-cement, and fracture load was applied and recorded. Results: Multiple comparisons were done using post-hoc Tukey's test and modality of failure of veneers among the different designs were done using Chi-square test with the level of significance fixed at 0.05. Conclusion: Ceramic veneers preparation design including1 mm incisal reduction along with 1 mm of palatal-chamfer height revealed greater fracture toughness in contrast to incisal-reduction 1 mm along with butt-joint preparation design.
Operative Dentistry, 2014
SUMMARY Purpose To evaluate the survival rate, success rate, load to fracture, and finite element analysis (FEA) of maxillary central incisors and canines restored using ceramic veneers and varying preparation designs. Methods and Materials Thirty human maxillary central incisors and 30 canines were allocated to the following four groups (n=15) based on the preparation design and type of tooth: Gr1 = central incisor with a conservative preparation; Gr2 = central incisor with a conventional preparation with palatal chamfer; Gr3 = canine with a conservative preparation; Gr4 = canine with a conventional preparation with palatal chamfer. Ceramic veneers (lithium disilicate) were fabricated and adhesively cemented (Variolink Veneer). The specimens were subjected to 4 × 106 mechanical cycles and evaluated at every 500,000 cycles to detect failures. Specimens that survived were subjected to a load to fracture test. Bidimensional models were modeled (Rhinoceros 4.0) and evaluated (MSC.Patra...
Marginal accuracy of press-ceramic veneers influenced by preparation design and fatigue
American journal of dentistry, 2007
To investigate the influence of preparation design and mouth motion fatigue on the marginal accuracy of press-ceramic veneers bonded to human maxillary central incisors. Forty-eight extracted human maxillary central incisors divided in three groups of 16 specimens each, received veneer preparations. In Group WP a window preparation (WP) was performed. Specimens in Group IOP were prepared with an incisal overlap (IOP) of 2 mm without palatal chamfer. For Group CVP, specimens received a complete-veneer preparation (CVP) of 3 mm incisal reduction and 2 mm palatal extension. Veneers were fabricated with IPS Empress and bonded adhesively with dual polymerizing composite Variolink II. The discrepancies of marginal fit were examined on epoxy replicas before and after mouth motion fatigue at x200 magnification. The mean (geometrical) (95% confidence limits) marginal accuracy after cementation was recorded as follows: WP-46 (43-49) microm, IOP-46 (44-49) microm and CVP-54 (51-58) microm. Fat...