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Dental Materials : Official Publication... May 2024Functionally graded materials (FGM) with indistinct boundaries potentially eliminate the damaging stresses occurring at the interfaces. FGM applications in dental... (Review)
Review
BACKGROUND
Functionally graded materials (FGM) with indistinct boundaries potentially eliminate the damaging stresses occurring at the interfaces. FGM applications in dental ceramics have enhanced their fatigue resistance and interfacial toughness.
OBJECTIVES
This scoping review aims to map graded designs in dental ceramics, distinguish their methodological approaches with their material characteristics and properties, and understand the factors affecting the outcomes of each of the graded approaches.
METHODS
A systematic electronic search was performed with the databases MEDLINE (PubMed), Scopus, Cochrane Library, EBSCO, and Google Scholar along with a manual search.
RESULTS
About 2675 articles were initially found from all the searches with no date restriction till July 2023. After rejecting duplicates and based on exclusion criteria, about 52 articles were included.
SIGNIFICANCE
Methodological approaches in grading such as glass-infiltration and silica-infiltration have been investigated on pre-sintered zirconia. The type of infiltration and the method of infiltrate application significantly influenced the phase transformation of zirconia, its microstructure, surface hardness, fracture toughness, flexural strength, wear, and fatigue strength of graded dental zirconia. Interlayers were accommodated between metal-ceramic and veneer-core all-ceramic layers. Fractions of zirconia-porcelain and alumina-porcelain showed high bending strength and better stress distribution. The results of finite element analysis studies predicted that using 10-layered graded layers reduced the stresses at the crown-cement-dentin interface.
Topics: Ceramics; Materials Testing; Zirconium; Surface Properties; Dental Materials; Humans; Dental Stress Analysis; Hardness; Dental Porcelain; Flexural Strength
PubMed: 38438282
DOI: 10.1016/j.dental.2024.02.016 -
The International Journal of... May 2024It is incumbent upon our profession to reevaluate our preference for routinely replacing a missing single maxillary incisor, especially a maxillary lateral incisor, with...
It is incumbent upon our profession to reevaluate our preference for routinely replacing a missing single maxillary incisor, especially a maxillary lateral incisor, with a dental implant in a young adult. The dental literature is replete with beautiful restorative results using implants in this area, but there is minimal discussion regarding the long-term consequences of this treatment. The maxillary lateral incisor is one of the most commonly missing teeth due to agenesis, and it is also one of the most common teeth to be lost due to trauma in the developing child.1 Therefore, the decision for replacement must be made with the long-term in mind, as these restorations are commonly placed between ages 18 and 21 and must serve the patient for many decades. There are several reasons that implants can be associated with complications or even fail, including the following: (1) Continued craniofacial growth, which has a predominant anterior and vertical component and has been shown to occur in the maxilla, resulting in the apparent submersion of the implant crown as the natural teeth move incisally in relation to the implant2,3-there is no evidence that this can be predicted, let alone how far into the future it may happen; (2) peri-implantitis, which has a patient-level prevalence estimate of nearly 25% according to the findings of a recent systematic review;4 (3) thinning and recession of the peri-implant mucosa due to poor implant placement, inadequate prosthetic management, and/or poor case selection, often resulting in compromised esthetics and a predisposition for the onset and progression of peri-implant diseases; and (4) mechanical failure of the implant, abutment screw, transmucosal abutment, and/or crown. Clinicians should also keep in mind that, once an implant is placed in the anterior maxilla, it precludes the possibility for palatal expansion in the adult patient because the space created by the expansion cannot be redistributed orthodontically. Canine substitution is one traditional method for replacement of the missing maxillary lateral incisor. It is still a viable option when the canine tooth has an acceptable shape and color, and the occlusion will not be compromised by the substitution.5 Additionally, the bonded single-wing zirconia bridge has become a primary treatment option.6 Zirconia has the strength of metal and beauty of porcelain, which makes it an ideal substrate for a bonded bridge. The literature has demonstrated the long-term success of this replacement option for the missing maxillary incisor.7 There are clearly many potential long-term disadvantages associated with replacing a single missing maxillary incisor with an implant in young adults. We should be prescribing the least-invasive treatment option for the replacement of these teeth. Therefore, when treatment-planning for a missing maxillary incisor in a young adult, alternatives to implant therapy-such as the bonded single-wing zirconia bridge and canine substitution-should be the primary treatment options. The implant should only be considered as a secondary treatment when the other options are not viable or have previously failed.
Topics: Humans; Incisor; Maxilla; Dental Implants, Single-Tooth; Anodontia; Young Adult; Dental Prosthesis, Implant-Supported; Peri-Implantitis
PubMed: 38787712
DOI: 10.11607/prd.2024.3.e -
Journal of Dentistry Jul 2024To give a comprehensive review of advancement in dental ceramics, fabrication methods, and the challenges associated with clinical application. (Review)
Review
OBJECTIVES
To give a comprehensive review of advancement in dental ceramics, fabrication methods, and the challenges associated with clinical application.
DATA, SOURCES AND STUDY SELECTION
Researches on chemical composition, biomechanical behaviors, optical properties, bonding strategies and fabrication methods were included. The search of articles was independently conducted by two authors in the PubMed, Scopus, Medline and Web of Science.
CONCLUSIONS
Dental ceramics have shown significant advancements in terms of esthetics and function. However, improving fracture toughness without compromising optical properties remains a challenge. Repairing fractured zirconia or glass-matrix ceramic prostheses with the same material is difficult due to the sintering process. Developing innovative bonding techniques that provide strong and long-lasting bonding strength between ceramics and tooth structures poses a recurring obstacle.
CLINICAL SIGNIFICANCE
Despite the emergence of dental ceramics and fabrication techniques, certain limitations such as susceptibility to brittleness and fracture still exist. Therefore, the current review provided valuable information around the advanced dental ceramics in tooth repair. The laboratory test data and the clinical outcome are also presented in details, aiming to guide clinicians in making informed decisions regarding ceramic restorations.
Topics: Humans; Ceramics; Zirconium; Dental Materials; Dental Bonding; Dental Porcelain; Esthetics, Dental; Materials Testing; Dental Prosthesis Design
PubMed: 38729288
DOI: 10.1016/j.jdent.2024.105053 -
Dental Materials : Official Publication... May 2024Lithium silicate-based glass ceramics have evolved as a paramount restorative material in restorative and prosthetic dentistry, exhibiting outstanding esthetic and... (Review)
Review
OBJECTIVES
Lithium silicate-based glass ceramics have evolved as a paramount restorative material in restorative and prosthetic dentistry, exhibiting outstanding esthetic and mechanical performance. Along with subtractive machining techniques, this material class has conquered the market and satisfied the patients' needs for a long-lasting, excellent, and metal-free alternative for single tooth replacements and even smaller bridgework. Despite the popularity, not much is known about the material chemistry, microstructure and terminal behaviour.
METHODS
This article combines a set of own experimental data with extensive review of data from literature and other resources. Starting at manufacturer claims on unique selling propositions, properties, and microstructural features, the aim is to validate those claims, based on glass science. Deep knowledge is mandatory for understanding the microstructure evolution during the glass ceramic process.
RESULTS
Fundamental glass characteristics have been addressed, leading to formation of time-temperature-transformation (TTT) diagrams, which are the basis for kinetic description of the glass ceramic process. Nucleation and crystallization kinetics are outlined in this contribution as well as analytical methods to describe the crystalline fraction and composition qualitatively and quantitatively. In relation to microstructure, the mechanical performance of lithium silicate-based glass ceramics has been investigated with focus on fracture strength versus fracture toughness as relevant clinical predictors.
CONCLUSION
Fracture toughness has been found to be a stronger link to initially outlined manufacturer claims, and to more precisely match ISO recommendations for clinical indications.
Topics: Ceramics; Silicates; Materials Testing; Glass; Surface Properties; Dental Materials; Crystallization; Lithium Compounds; Dental Porcelain
PubMed: 38580561
DOI: 10.1016/j.dental.2024.03.006 -
Materials (Basel, Switzerland) Dec 2023Dental zirconias have been broadly utilized in dentistry due to their high mechanical properties and biocompatibility. Although initially introduced in dentistry as an... (Review)
Review
Dental zirconias have been broadly utilized in dentistry due to their high mechanical properties and biocompatibility. Although initially introduced in dentistry as an infrastructure material, the high rate of technical complications related to veneered porcelain has led to significant efforts to improve the optical properties of dental zirconias, allowing for its monolithic indication. Modifications in the composition, processing methods/parameters, and the increase in the yttrium content and cubic phase have been presented as viable options to improve zirconias' translucency. However, concerns regarding the hydrothermal stability of partially stabilized zirconia and the trade-off observed between optical and mechanical properties resulting from the increased cubic content remain issues of concern. While the significant developments in polycrystalline ceramics have led to a wide diversity of zirconia materials with different compositions, properties, and clinical indications, the implementation of strong, esthetic, and sufficiently stable materials for long-span fixed dental prostheses has not been completely achieved. Alternatives, including advanced polycrystalline composites, functionally graded structures, and nanosized zirconia, have been proposed as promising pathways to obtain high-strength, hydrothermally stable biomaterials. Considering the evolution of zirconia ceramics in dentistry, this manuscript aims to present a critical perspective as well as an update to previous classifications of dental restorative ceramics, focusing on polycrystalline ceramics, their properties, indications, and performance.
PubMed: 38138684
DOI: 10.3390/ma16247541 -
Cureus Apr 2024Aim This retrospective study aimed to evaluate if E-max veneers over five years caused changes in gingival, periodontal health, and veneer failures. Background As...
Aim This retrospective study aimed to evaluate if E-max veneers over five years caused changes in gingival, periodontal health, and veneer failures. Background As aesthetic dentistry progresses, dental veneers are becoming increasingly popular in both general and specialized dental practices. Due to technological advancements in dental ceramics and adhesive systems, porcelain veneers have become a highly sought-after solution for improving aesthetics in dental patients. The success of porcelain laminate veneers, a commonly used method for aesthetic restoration, relies on various factors. E-max veneers are frequently utilized, with their long-term durability contingent upon factors such as color stability, resistance to abrasion, as well as good compressive, tensile, and shear strength, along with maintaining marginal integrity. Methodology In this study, data was collected through a checklist form used to record clinical parameters. The clinical parameters evaluated were inflammation and bleeding on probing (BOP). The gingival health was evaluated by gingival index, gingival color, texture, and bleeding on probing, and periodontal health was evaluated by the pocket depth and radiographic evaluations. Finally, the veneer was visually inspected for chipping, staining, and debonding history. The score for most of the cases ranged between 0-1, with only 10 cases displaying moderate gingival inflammation and BOP (Gingival Index 2). Siemens Orthopantomogram (OPG) systems were used for radiological evaluation and documentation of cases. E-max porcelain veneers were only included in the research. Results Out of 28 patients, each with 6-to-10-unit veneer cases was examined, 18 patients (64.3%) displayed healthy gingival status with no bleeding area recorded in none of the veneers amongst the 6 to 10 units. In 10 patients (35.7%) most of the veneers had inflamed gingival tissue that was bleeding on probing. The majority revealed the presence of stippling (92.9%), absence of recession (96.4%), and pocket depth (67.9%). Half of our participants had their veneer for more than five years (50%) and the majority presented with no significant changes in veneer recorded like marginal staining, debonding, or chipping (89.3%). Conclusion Multiple factors such as patient selection, proper treatment planning, and design, including material selection, play a significant role in the long-lasting success of ceramic veneers. The retrospective study indicated that proper oral hygiene measures are vital for the long-term sustainability of E max veneers.
PubMed: 38800248
DOI: 10.7759/cureus.58957 -
Materials (Basel, Switzerland) Jul 2023The clinical success of porcelain laminate veneers (PLVs) depends on many clinical and technical factors, from planning to execution, among which adhesive cementation is... (Review)
Review
The clinical success of porcelain laminate veneers (PLVs) depends on many clinical and technical factors, from planning to execution, among which adhesive cementation is of significant importance. This procedure carries many risk factors if not optimally executed. The objective of this study was to document the clinical parameters affecting successful cementation procedures with a focus on the adhesive strength, integrity, and esthetics of the PLVs. A literature search was conducted through MEDLINE, complemented by a hand search using predefined keywords. Articles published in English between 1995 and 2023 were selected. According to this review, the success and longevity of PLVs rely in great part on the implementation of a precise cementation technique, starting from field isolation, adequate materials selection for adhesion, proper manipulation of the materials, the seating of the veneers, polymerization, and elimination of the excess cement. Several clinical steps performed before cementation, including treatment planning, preparation, impression, and adequate choice of the restorative material, could affect the quality of cementation. Scientific evidence suggests careful implementation of this process to achieve predictable outcomes with PLVs. The short- and long-term clinical success of adhesively luted PLVs is tributary to a deep understanding of the materials used and the implementation of clinical protocols. It is also contingent upon all the previous steps from case selection, treatment planning, and execution until and after the cementation.
PubMed: 37512206
DOI: 10.3390/ma16144932 -
Dental Materials Journal Sep 2023The purpose of the study was the investigation of the polymerization of a preheated composite resin beneath lithium disilicate. First, lithium disilicate discs in two...
The purpose of the study was the investigation of the polymerization of a preheated composite resin beneath lithium disilicate. First, lithium disilicate discs in two shades (HT A2 and HT A4) and three different thicknesses (2, 4, and 6 mm) were bonded on dentine with preheated composite resin that was photo-polymerized for 20 s. The composite resin microhardness, the double bond conversion (DC) and their correlation were estimated. Second, standardized occlusal veneers of two shades and two different thicknesses (4 and 6 mm) were bonded with preheated composite resin and photopolymerized for 60 or 270 s. A microhardness line profiling was performed on the cross-section of each specimen and the correspondence DC was calculated. Shade and thickness of lithium disilicate were found to have a significant impact on micro-hardness and DC of the composite resin. Beneath standardized occlusal veneers DC can reach clinically acceptable level if photopolymerization duration is extended properly.
Topics: Composite Resins; Dental Veneers; Materials Testing; Dental Porcelain; Resin Cements; Ceramics
PubMed: 37661372
DOI: 10.4012/dmj.2023-057 -
The Journal of Prosthetic Dentistry May 2024The increasing use of computer-aided design and computer-aided manufacturing (CAD-CAM) systems has led to the development of resin-ceramic materials that meet the... (Review)
Review
STATEMENT OF PROBLEM
The increasing use of computer-aided design and computer-aided manufacturing (CAD-CAM) systems has led to the development of resin-ceramic materials that meet the requirements of minimally invasive dentistry, including the resin nanoceramic (RNC) and polymer-infiltrated ceramic network (PICN). The wear characteristics of these materials are unclear.
PURPOSE
The purpose of this systematic review was to compare the wear resistance of resin-ceramic materials when compared with one another or with lithium disilicate glass-ceramics.
MATERIAL AND METHODS
The PubMed, Scopus, and DOSS search engines were used to identify articles published between 2013 and 2021. Two independent researchers conducted the systematic review by following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines and by following a combination of keywords.
RESULTS
Of a total of 310 articles, 26 were selected, including only 1 clinical study. Among these, 15 compared resin-ceramic materials with each other, while 11 compared resin-ceramic materials with lithium disilicate ceramics. Two types of wear were used to compare the materials: attrition and abrasion. The most commonly studied materials were 2 RNCs (Lava Ultimate and Cerasmart), 1 PICN (Vita Enamic), and 1 ceramic (IPS e.max CAD). Among the resin-ceramic materials, the PICN (Vita Enamic) showed less wear than the RNCs. Of the RNCs, Cerasmart had less attrition wear and less wear of the opposing teeth.
CONCLUSIONS
Lithium disilicate glass-ceramics have a higher wear resistance than resin-ceramic materials, but they cause more wear of the opposing teeth.
Topics: Computer-Aided Design; Ceramics; Humans; Dental Porcelain; Dental Restoration Wear; Dental Materials; Resins, Synthetic
PubMed: 35459543
DOI: 10.1016/j.prosdent.2022.01.027 -
Clinical Oral Implants Research Sep 2023The objectives of the study were to assess the survival, failure, and technical complication rates of implant-supported fixed dental prosthesis (iFDPs) with pontic or... (Meta-Analysis)
Meta-Analysis Review
Systematic review evaluating the influence of the prosthetic material and prosthetic design on the clinical outcomes of implant-supported multi-unit fixed dental prosthesis in the posterior area.
OBJECTIVE
The objectives of the study were to assess the survival, failure, and technical complication rates of implant-supported fixed dental prosthesis (iFDPs) with pontic or splinted crown (iS C) designs in the posterior area and compare the influence of prosthetic materials and prosthetic design on the outcomes.
METHODS
Electronic and manual searches were performed to identify randomized-, prospective-, and retrospective clinical trials with follow-up time of ≥12 months, evaluating the clinical outcomes of posterior iFDPs with pontic or iS Cs. Survival and complication rates were analyzed using robust Poisson's regression models.
RESULTS
Thirty-two studies reporting on 42 study arms were included in the present systematic review. The meta-analysis of the included studies indicated estimated 3-year survival rates of 98.3% (95%CI: 95.6-99.3%) for porcelain-fused-to-metal (PFM) iFDPs, 97.5% (95%CI: 95.5-98.7%) for veneered zirconia (Zr) iFDPs with pontic, 98.9% (95%CI: 96.8-99.6%) for monolithic or micro-veneered zirconia iFDPs with pontic, and 97.0% (95%CI: 84.8-99.9%) for lithium disilicate iFDPs with pontics. The survival rates for different material combination showed no statistically significant differences. Veneered restorations, overall, showed significantly (p < .01) higher ceramic fracture and chipping rates compared with monolithic restorations. Furthermore, there was no significant difference in survival rates (98.3% [95%CI: 95.6-99.3%] vs. 99.1% [95%CI: 97.6-99.7%]) and overall complication rates between PFM iFDPs with pontic and PFM iS Cs.
CONCLUSIONS
Based on the data identified by this systematic review, PFM, veneered Zr, and monolithic Zr iFDPs with pontic and iS Cs showed similarly high short-term survival rates in the posterior area. Veneered restorations exhibit ceramic chipping more often than monolithic restorations, with the highest fracture rate reported for veneered Zr iFDPs.
Topics: Prospective Studies; Retrospective Studies; Dental Prosthesis Design; Dental Restoration Failure; Dental Porcelain; Ceramics; Zirconium; Crowns; Dental Prosthesis, Implant-Supported
PubMed: 37750526
DOI: 10.1111/clr.14103