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The International Journal of... Apr 2024To study the degree of accuracy in gingival shade matching of undergraduate students using a computer application.
PURPOSE
To study the degree of accuracy in gingival shade matching of undergraduate students using a computer application.
MATERIALS AND METHODS
In total, 76 undergraduate dental students' gingival shade selection abilities were evaluated using an in-house developed computer application. A total of 15 intraoral gingival photographs and 21 pink gingival color porcelain samples were used. The environmental conditions were standardized, and no time limit was set for answering in the computer application.
RESULTS
Fourteen gingival color samples (66.6%) were not useful for representing the studied gingival shades. Not all natural gingival colors studied were represented within the 50.50% acceptability limits of the pink samples. There were no statistically significant differences between men and women in terms of "hit" percentages. The highest correlation coefficient (in absolute value) was for the L* coordinate (the darker the gingiva in the picture, the higher the hit rate for choosing the "ideal" shade tab); however, none of the linear correlation coefficients were statistically significant.
CONCLUSIONS
Not all colors provided in the pink ceramic system were useful for subjective gingival selection. There were no statistically significant differences between male and female dental students in gingival color perception. The L* coordinate was the only one that influenced the correct perception of gingival color by dental students, and it did so more in women than in men.
Topics: Humans; Students, Dental; Female; Male; Prosthesis Coloring; Gingiva; Color; Dental Porcelain; Young Adult; Adult; Photography, Dental
PubMed: 38648162
DOI: 10.11607/ijp.8187 -
Journal of Esthetic and Restorative... Oct 2023To evaluate clinical outcome of maxillary midline diastema closure using sectional feldspathic porcelain veneers up to 4 years.
OBJECTIVE
To evaluate clinical outcome of maxillary midline diastema closure using sectional feldspathic porcelain veneers up to 4 years.
MATERIALS AND METHODS
Five female patients with stable maxillary midline diastema were included in the current study and restored with minimal invasive sectional feldspathic porcelain veneers under dental microscope. Esthetic, functional, as well as biologic properties of sectional veneers were evaluated according to the World Dental Federation (FDI) criteria after 1 to 4 years' follow-up.
RESULTS
Based on FDI criteria, all five cases were evaluated as clinically excellent to satisfactory during a mean observation period of 26.4 months. Slight to moderate cervical marginal staining was observed in two cases after 3 to 4 years' follow-up. Slight white line or ditching of labial surface margin was found in most cases, but it is not easy to be noticed with saliva covering the margins.
CONCLUSIONS
Sectional feldspathic porcelain veneers presented satisfying clinical outcome with potential long-term esthetic risk for maxillary midline diastema closure.
CLINICAL SIGNIFICANCE
1. Sectional feldspathic porcelain veneers presented satisfying short to medium term clinical performance when applied to close maxillary midline diastema. 2. The exposure of labial surface margin may increase a long-term potential esthetic risk.
Topics: Humans; Female; Dental Porcelain; Diastema; Dental Veneers
PubMed: 36946620
DOI: 10.1111/jerd.13034 -
Clinical Oral Investigations Sep 2023The aim of this systematic review and meta-analysis is to assess the comparative clinical success and survival of intracoronal indirect restorations using gold, lithium... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
The aim of this systematic review and meta-analysis is to assess the comparative clinical success and survival of intracoronal indirect restorations using gold, lithium disilicate, leucite, and indirect composite materials.
MATERIAL AND METHODS
This systematic review and meta-analysis were conducted following the Cochrane Handbook for Systematic Reviews of Interventions and PRISMA guidelines. The protocol for this study was registered in PROSPERO (registration number: CRD42021233185). A comprehensive literature search was conducted across various databases and sources, including PubMed/Medline, Embase, Cochrane Library, Web of Science, ClinicalTrials.gov, and gray literature. A total of 7826 articles were screened on title and abstract. Articles were not excluded based on the vitality of teeth, the language of the study, or the observation period. The risk difference was utilized for the analyses, and a random-effects model was applied. All analyses were conducted with a 95% confidence interval (95% CI). The calculated risk differences were derived from the combined data on restoration survival and failures obtained from each individual article. The presence of heterogeneity was assessed using the I statistic, and if present, the heterogeneity of the data in the articles was evaluated using the non-parametric chi-squared statistic (p < 0.05).
RESULTS
A total of 12 eligible studies were selected, which included 946 restorations evaluated over a minimum observation period of 1 year and a maximum observation period of 7 years. Results of the meta-analysis indicated that intracoronal indirect resin composite restorations have an 18% higher rate of failure when compared to intracoronal gold restorations over 5-7 years of clinical service (risk difference = - 0.18 [95% CI: - 0.27, - 0.09]; p = .0002; I = 0%). The meta-analysis examining the disparity in survival rates between intracoronal gold and leucite restorations could not be carried out due to methodological differences in the studies.
CONCLUSIONS
According to the currently available evidence, medium-quality data indicates that lithium disilicate and indirect composite materials demonstrate comparable survival rates in short-term follow-up. Furthermore, intracoronal gold restorations showed significantly higher survival rates, making them a preferred option over intracoronal indirect resin-composite restorations. Besides that, the analysis revealed no statistically significant difference in survival rates between leucite and indirect composite restorations. The short observation period, limited number of eligible articles, and low sample size of the included studies were significant limitations.
CLINICAL SIGNIFICANCE
Bearing in mind the limitations of the reviewed literature, this systematic review and meta-analysis help clinicians make evidence-based decisions on how to restore biomechanically compromised posterior teeth.
Topics: Dental Porcelain; Aluminum Silicates; Composite Resins; Gold
PubMed: 37597003
DOI: 10.1007/s00784-023-05050-x -
Journal of the Mechanical Behavior of... Dec 2023This study investigated the impact of preparation design and material types on fracture strength in maxillary premolars endocrowns after thermodynamic aging.
PURPOSE
This study investigated the impact of preparation design and material types on fracture strength in maxillary premolars endocrowns after thermodynamic aging.
MATERIALS AND METHODS
Eighty two-rooted maxillary premolar crowns underwent endodontic treatment (N = 80, n = 10). The teeth were categorized into ten groups (4-mm deep with no intracanal extension lithium disilicate glass ceramic & multilayer zirconia endocrowns (LE0 & ZE0); 4-mm deep with 4-mm intracanal extension in one canal (LE1 & ZE1); 4-mm deep with 2-mm intracanal extensions in both canals (LE2 & ZE2); flat overlays with no endocore (LO & ZO); glass fiber reinforced post & core and crown (LC & ZC)). After cementation, all specimens were subjected to 1500 thermocycles and 1,200,000 chewing cycles with an axial occlusal load of 49 N. A static loading test was performed at a non-axial 45° loading using a universal testing machine and failure modes (Type I: restoration debonding; Type II: restoration fracture; Type III: restoration/tooth complex fracture above bone level; Type IV: restoration/tooth complex fracture below bone level) were evaluated using a stereoscope. Data were ananalzed using 2-way ANOVA and Tukey's tests (alpha = 0.05).
RESULTS
The endocrowns manufactured from multilayered zirconia and pressed lithium disilicate glass ceramic exhibited a fracture load ranging between 1334 ± 332 N and 756 ± 150 N, with ZC presenting the highest and LE2 the lowest values. The differences were not statistically significant (p > 0.05).
CONCLUSION
All endocrowns tested in this study performed similar considering the different designs and materials tested. The distribution of fracture modes did not differ significantly depending on the design of the restoration and the type of material used.
Topics: Humans; Flexural Strength; Materials Testing; Computer-Aided Design; Zirconium; Ceramics; Dental Porcelain; Tooth Fractures; Dental Stress Analysis; Dental Restoration Failure
PubMed: 37839334
DOI: 10.1016/j.jmbbm.2023.106184 -
Journal of Applied Biomaterials &... 2024Despite the development of implant-supported prostheses, there are still patients for whom conservative treatments such as resin-bonded fixed dental prostheses (RBFDPs)... (Review)
Review
Despite the development of implant-supported prostheses, there are still patients for whom conservative treatments such as resin-bonded fixed dental prostheses (RBFDPs) are more appropriate. This study's objective was to analyze the available research on full-ceramic RBFDPs. In this study, Web of Science, MEDLINE/PubMed, Scopus, Embase, Cochrane Library, and Google Scholar databases were searched for articles published in English between 2010 and 2020. A total of 14 studies were reviewed based on the eligibility criteria. The results showed that using a cantilever design with one abutment had an advantage over two abutments. Additionally, it was proposed that preparations designed with retentive aids, such as a proximal box, groove, and pinhole, could improve RBFDP survival rates. IPS e.max ZirCAD, In-Ceram alumina, and zirconia CAD/CAM were the most commonly used framework materials. Most studies used air abrasion, salinization, or hydrofluoric acid for surface treatment. Adhesive resin cements were the most frequently used type of cement. The survival rate of In-Ceram ceramics (85.3%-94.8%) was lower than that of In-Ceram zirconia and IPS e.max ZirCAD. Debonding, followed by framework fracture, was the leading cause of failure. Following 3-10 years follow-up, the survival percentage of all-ceramic RBFDPs ranged from 76% to 100%. Although RBFDPs have demonstrated satisfactory success as a conservative treatment, long-term follow-ups and higher sample sizes in clinical research are required to gain more reliable outcomes on the clinical success rate of various RBFDP designs.
Topics: Humans; Ceramics; Resin Cements; Dental Porcelain; Dental Prosthesis, Implant-Supported; Denture, Partial, Fixed, Resin-Bonded; Zirconium
PubMed: 38706266
DOI: 10.1177/22808000241250118 -
Scientific Reports May 2024This study aimed to assess the knowledge regarding impacts, causes and management of black triangles (BT) among participants from different educational backgrounds... (Observational Study)
Observational Study
This study aimed to assess the knowledge regarding impacts, causes and management of black triangles (BT) among participants from different educational backgrounds including dental students, dentists and laypeople. This descriptive cross-sectional observational research included 435 participants who comprised 4 groups: pre-clinical (3rd year) dental students, clinical (4th and 5th year) dental students, dentists, and laypeople. A constructed self-reported questionnaire was utilized to assess participants' demographic data and their knowledge of the impacts, causes and management of BT. The VAS scale was used to assess participants' ratings for the impacts of BT on esthetics, with 0 meaning no impact and 10 meaning very severe negative impacts. The most reported treatments for BT were "cannot be treated" 99.3% and "non-surgical periodontal treatment" 67.1%. Meanwhile, the least reported was "modify the porcelain" 41.8%. The most reported cause of BT was "periodontal disease" 85.1%. However, the least reported were "parafunction" and "deep implants" 33.1% each. Dental professionals had better knowledge of the causes (t = 8.189, P < 0.001) and management (t = 8.289, P < 0.001) of BT than the non-dental participants. The dentists had the best knowledge, while the laypeople had the least knowledge of the causes (F = 62.056, P < 0.001) and treatment (F = 46.120, P < 0.001) of BT. The knowledge of the causes (t = 0.616, P = 0.538) and treatment (t = 1.113, P = 0.266) for BT was not significantly different between males and females. Age was not significantly related to the total knowledge about the causes (r = -0.034, P = 0.475) or treatment (r = -0.034, P = 0.482) for BT. Dental professionals had better knowledge of the impacts, causes and management of BT than the non-dental participants. The dentists were the best, while the laypeople were the worst in this regard. Age and gender had no relationships with the knowledge of causes or management of BT.
Topics: Humans; Male; Female; Dentists; Adult; Cross-Sectional Studies; Health Knowledge, Attitudes, Practice; Surveys and Questionnaires; Students, Dental; Young Adult; Middle Aged
PubMed: 38735998
DOI: 10.1038/s41598-024-61356-0 -
Journal of Prosthodontic Research Apr 2024Partial laminate veneers, defined as small ceramic restorations adhesively luted onto unprepared anterior teeth, are an interesting and conservative alternative to... (Review)
Review
STUDY SELECTION
Partial laminate veneers, defined as small ceramic restorations adhesively luted onto unprepared anterior teeth, are an interesting and conservative alternative to conventional ceramic and composite resin veneers in the anterior region. This literature review aimed to summarize the available laboratory and clinical data on ceramic partial laminate veneers. An electronic search of the MEDLINE/PubMed, EBSCO, and Web of Science databases was conducted. The keywords used were "partial veneer," "partial laminate veneer," "ceramic fragment," and "sectional veneer." The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. The risk of bias in the included studies was assessed using the QUIN tool.
RESULTS
Of the 266 identified articles, only 16 met the inclusion criteria (ten clinical reports, five laboratory studies, and one retrospective clinical study). To date, no randomized controlled clinical trials have been conducted. Most laboratory studies displayed a low risk of bias, with partial laminate veneers rendering adequate strength and color stability. Clinical reports have shown large variability in material selection, luting, and finishing/polishing protocols.
CONCLUSIONS
Low-quality evidence is available for ceramic partial laminate veneers. Available data from laboratory studies suggest good mechanical and optical performances comparable to those of conventional ceramic and composite resin veneers. Further clinical studies with longer follow-up periods are warranted.
Topics: Dental Porcelain; Retrospective Studies; Dental Veneers; Ceramics; Composite Resins; Resin Cements
PubMed: 37648480
DOI: 10.2186/jpr.JPR_D_23_00090 -
Evidence-based Dentistry Dec 2023In vitro primary research study.
DESIGN
In vitro primary research study.
CASE SELECTION AND METHOD
Five frequently used restorative dental ceramic materials (pressable ceramics (PEmax), pressed and layered ceramics (LEmax), layered zirconia (LZr), monolithic zirconia (MZr) and porcelain fused to metal (PFM)) were selected and manufactured in shade A1. Samples of each material were prepared in discs and kept in water at 37°C for 24 hours then aged via thermocycling. Samples were positioned in a plastic chamber to mimic the intraoral setting and exposed to vape smoke through an artificial lung vacuum system. The procedure was repeated until target exposure puffs were achieved, ranging from 250-1500 puffs. The ECDs/vape device, refill juice and concentration used for puff generation were chosen based on a survey reporting high consumption. A spectrophotometer was used to measure sample colour through L*a*b values (lightness, axes of green, red, blue and yellow). CIELAB formula was used to calculate total colour difference (∆E) at six time intervals.
DATA ANALYSIS
One-way analysis of variance (ANOVA) and Tukey's posthoc testing was used to compare mean ∆E values with 95% confidence intervals for all specimens. Cut off for significance was α < 0.05.
RESULTS
All ceramics showed colour variation following exposure to ECD aerosol. With the exception of PEmax, all tested materials lightness values changed following exposure to 250 puffs. At 1500 puff exposures, LEmax, LZr and MZr showed significant colour changes, whereas PEmax and PFM showed clinically acceptable and insignificant change.
CONCLUSIONS
Colour change of dental ceramics varies depending on the ceramic material used and puff exposure number. Exposure to ECD aerosols can result in aesthetically noticeable colour changes in LEmax, LZr and MZr. Colour changes demonstrated are less than those caused by traditional tobacco smoking.
Topics: Humans; Aged; Electronic Nicotine Delivery Systems; Vaping; Color; Dental Porcelain; Ceramics; Dental Materials
PubMed: 37957239
DOI: 10.1038/s41432-023-00953-w -
The Journal of Prosthetic Dentistry Aug 2023New computer-aided design and computer-aided manufacturing (CAD-CAM) lithium disilicate glass-ceramics have been marketed. However, information concerning their...
STATEMENT OF PROBLEM
New computer-aided design and computer-aided manufacturing (CAD-CAM) lithium disilicate glass-ceramics have been marketed. However, information concerning their biomechanical behavior is lacking.
PURPOSE
The purpose of this in vitro study was to compare the fit and fatigue behavior of two recently introduced CAD-CAM lithium disilicate materials with the standard IPS e.max CAD ceramic and to investigate the effect of the thermal treatment for crystallization on crown fit.
MATERIAL AND METHODS
Monolithic crowns (n=15) were milled from 3 CAD-CAM lithium disilicates: IPS e.max CAD (Ivoclar AG), Rosetta SM (Hass), and T-lithium (Shenzhen Upcera Dental Technology). Marginal and internal fit were evaluated using the replica technique before and after crystallization, and the fatigue behavior of the luted crowns was evaluated by the step-stress method. One-way ANOVA and the Tukey test were used to compare fit among the materials. Fatigue failure load was evaluated by the Kaplan-Meier and Mantel-Cox tests. The effect of crystallization on fit was evaluated with the paired t test (α=.05).
RESULTS
Marginal fit was different between IPS e.max CAD (74 μm) and Rosetta SM (63 μm) (P=.02). T-lithium was similar to the other ceramics (68 μm) (P>.05). Occlusal internal space was similar among all materials (P=.69). Fatigue failure loads of Rosetta SM (1160 N) and T-lithium (1063 N) were similar to IPS e.max CAD (1082 N) (P>.05). The fatigue failure load of Rosetta SM was higher than that of T-lithium (P=.04). Crystallization reduced the axial internal space of all materials (P<.05) without significantly affecting marginal fit (P>.05).
CONCLUSIONS
The fit and fatigue behavior of Rosetta SM and T-lithium were similar to that of IPS e.max CAD. Crystallization reduced the internal space of the crowns.
Topics: Ceramics; Lithium; Dental Prosthesis Design; Surface Properties; Dental Marginal Adaptation; Dental Impression Technique; Dental Stress Analysis; Materials Testing; Dental Porcelain; Crowns; Computer-Aided Design
PubMed: 37328406
DOI: 10.1016/j.prosdent.2023.05.007 -
Journal of the Mechanical Behavior of... Nov 2023The aim of this study was to evaluate the surface properties and fatigue mechanical behavior of an advanced lithium disilicate ceramic in comparison to lithium...
The aim of this study was to evaluate the surface properties and fatigue mechanical behavior of an advanced lithium disilicate ceramic in comparison to lithium disilicate and zirconia. First, discs (n = 15, diameter = 13.5 mm and thickness = 1.2 mm) were made from the following materials: 4Y-PSZ - 4% mol yttria-stabilized zirconia (IPS e.max ZirCAD A2); LD - lithium disilicate (IPS e.max CAD); ALD - advanced lithium disilicate (CEREC Tessera). The specimens were crystalized/sintered and subsequently analyzed by a rugosimeter (Mitutoyo SJ-410) to determine surface roughness (parameters Ra and Rz). Specimens were subjected to biaxial flexural fatigue testing using the step-test method (20 Hz; 10,000 cycles per step; initial stress of 200 MPa; and step size of 25 MPa) until specimen fracture. Statistical analyses included Shapiro-Wilk, Kruskal-Wallis, and post-hoc tests for roughness data, while survival analysis (Kaplan-Meier and Mantel-Cox) and reliability analysis (Weibull modulus) were applied to flexural fatigue strength data. Hardness (Vickers) results were submitted to analysis of variance (1-way ANOVA) and Tukey's test. Zirconia (4Y-PSZ) showed higher FFS, CFF (467 MPa and 115216 cycles) and survival compared to the other materials. ALD had the lowest FFS, CFF (215 MPa and 11,908 cycles) and survival. ALD showed lower Weibull modulus (m = 6.63 for FFS; m = 1.27 for CFF) than LD for FFS (m = 17.33), and lower than LD (m = 4.64) and 4Y-PSZ (m = 6.69) for CFF. ALD showed the lowest Ra (0.07 μm) and Rz (1.05 μm) values, while 4Y-PSZ (Ra = 0.22 μm; Rz = 1.91 μm) and LD (Ra = 0.21 μm; Rz = 2.17 μm) showed higher and similar values. Zirconia (4-YPSZ) was the hardest material, while lithia-based ceramics (LD and ALD) presented the lowest and similar hardness values. Fractures originated in surface defects in the tensile stress concentration region. ALD has lower flexural fatigue strength compared to the other tested materials, along with higher variability (lower structural reliability).
Topics: Materials Testing; Reproducibility of Results; Computer-Aided Design; Dental Porcelain; Zirconium; Ceramics; Surface Properties; Dental Stress Analysis
PubMed: 37804677
DOI: 10.1016/j.jmbbm.2023.106154