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Clinical Oral Investigations May 2023To study the fracture resistance and stress distribution pattern of translucent zirconia and fiber-reinforced composite cantilever resin-bonded fixed dental prostheses...
OBJECTIVE
To study the fracture resistance and stress distribution pattern of translucent zirconia and fiber-reinforced composite cantilever resin-bonded fixed dental prostheses (RPFDPs) with two retainer designs.
MATERIALS AND METHODS
Forty human mandibular molars were divided into two groups according to the retainer design. The restorations included a premolar pontic and 2 retainer designs: (D1) inlay ring retainer and (D2) lingual coverage retainer. Each main group was then divided according to the material used (n = 10): zirconia (Z) or fiber-reinforced composite (FRC) (F). Restorations were cemented using dual polymerizing adhesive luting resin. All specimens were thermo-cycled (5-55 °C for 10,000 cycles), then subjected to dynamic loading (50 N, 240,000, and 1.6 Hz) and fracture resistance test. The finite element analysis includes the two models of retainer designs used in the in vitro test. Modified von Mises stress values on enamel, dentin, luting resin, and restorations were examined when the restorations failed.
RESULTS
A significantly higher failure load was recorded for zirconia groups (505.00 ± 61.50 and 548.00 ± 75.63 N for D1Z and D2Z, respectively) than for FRC groups (345.00 ± 42.33 and 375.10 ± 53.62 N for D1F and D2F, respectively) (P = 0.001). With regard to failure mode, D2 showed a more favorable failure pattern than D1. Model D2 resulted in lower stresses in tooth structure than model D1, and zirconia transmitted more stresses to the tooth structure than FRC.
CONCLUSIONS
The lingual coverage retainer (D2) enhanced the biomechanical performance of the restoration/tooth complex. Considering the failure mode and tooth stress, FRC is a promising treatment option when constructing a cantilever RPFDP.
CLINICAL RELEVANCE
Dentists should be aware of the biomechanical behavior during the selection of the material and for the replacement of a single missing mandibular premolar tooth with minimally invasive RBFDP.
Topics: Humans; Denture Design; Dental Restoration Failure; Composite Resins; Zirconium; Dental Stress Analysis
PubMed: 36456895
DOI: 10.1007/s00784-022-04813-2 -
Journal of Esthetic and Restorative... Dec 2022Evaluation of the effect of preparation type (inlay, onlay, and crown) on the accuracy of different intraoral scanning (IOS) systems at the preparation and arch segment...
OBJECTIVE
Evaluation of the effect of preparation type (inlay, onlay, and crown) on the accuracy of different intraoral scanning (IOS) systems at the preparation and arch segment levels.
MATERIALS AND METHODS
Three molars were prepared for inlay, onlay, and crown. Each preparation was scanned 10 times by CEREC Omnicam, Trios 3 (TS), and Medit i500 scanners. Each image was trimmed twice. The first trimming produced a preparation image (PI), and the second trimming extracted a segment image (SI) that involved the preparation with the adjacent teeth. Trueness and precision were calculated at the PI and SI levels.
RESULTS
At the PI level, all IOS systems had similar trueness pattern for all preparations, where the inlay had the best trueness followed by the crown and onlay. At the SI level, the different preparations showed similar trueness. The precision did not show a clear pattern of superiority for any preparation. The TS was significantly more precise than other IOS systems at the PI and SI levels, for every preparation. The proximal areas suffered from the greatest errors, regardless of preparation type.
CONCLUSIONS
The preparation type influenced PI trueness, and the IOS system affected PI and SI precisions.
CLINICAL SIGNIFICANCE
The smaller and less complex preparations have greater IOS accuracy than larger and more complex preparations. As the proximal areas are more affected regardless of the preparation, a more accessible proximal area for scanning is desirable.
Topics: Dental Impression Technique; Models, Dental; Dental Arch; Computer-Aided Design; Imaging, Three-Dimensional
PubMed: 36415928
DOI: 10.1111/jerd.12949 -
Journal of the Mechanical Behavior of... Jan 2023The purpose of this in-vitro study was to investigate the effect of framework design on fracture resistance and failure modes of cantilever inlay-retained fixed partial...
PURPOSE
The purpose of this in-vitro study was to investigate the effect of framework design on fracture resistance and failure modes of cantilever inlay-retained fixed partial dentures (IRFDPs) fabricated from two multilayered monolithic zirconia materials.
MATERIALS AND METHODS
Seventy-two natural premolar teeth were prepared as abutments for cantilever IRFDPs using three designs: mesial-occlusal (MO) inlay with short buccal and palatal wings (D1), MO inlay with long palatal wing (D2), MO inlay with long palatal wing and occlusal extension (D3). Full-contoured IRFDPs were fabricated from two monolithic zirconia materials; IPS e.max ZirCAD Prime and Zolid Gen-X. Adhesive surfaces were air-abraded and bonded with MDP-containing resin cement. Specimens were subjected to thermocycling (5-55 °C, 5000 cycles); then, mechanical loading (1.2 × 10⁶ cycles, 49 N). Surviving specimens were loaded until failure in the universal testing machine. All specimens were examined under stereomicroscope, and two samples from each group were evaluated using Scanning Electron Microscope.
RESULTS
Mean failure loads were not significantly different between different framework designs or between two materials. However, IPS e.max ZirCAD Prime showed significantly higher failure rate than Zolid Gen-X during dynamic fatigue (p = 0.009). Samples with D1 design showed higher debonding rate, D2 failed mainly by fracture of the palatal wing and debonding, and D3 failed mainly by fracture of the abutment tooth. Debonded restorations showed mainly mixed failures.
CONCLUSION
Cantilever IRFDPs with framework designs that maximize adhesion to enamel exhibited promising results. IPS e.max ZirCAD Prime was more susceptible to fractures with the long palatal wing design.
Topics: Denture Design; Zirconium; Ceramics; Denture, Partial, Fixed; Dental Restoration Failure; Dental Stress Analysis; Dental Porcelain; Materials Testing
PubMed: 36370641
DOI: 10.1016/j.jmbbm.2022.105547 -
Cureus Sep 2022Aesthetic dentistry continues to evolve via advances in bonding agents, restorative materials, and conservative preparation methods. Alternatives to dental amalgam and...
Aesthetic dentistry continues to evolve via advances in bonding agents, restorative materials, and conservative preparation methods. Alternatives to dental amalgam and gold include ceramic dental restorative materials. The lifespan of ceramic inlay repairs is still up for debate. When it comes to durability, colour matching, and anatomical shape stability, ceramic inlay restorations top the list of options. More predictable long-term performance may be achieved by strategically placing ceramic inlays in teeth that are not subjected to significant occlusal stress. Preparation design for ceramic inlay materials is necessary to avoid flexure. This case report discusses the ceramic inlay practice for functional and aesthetic restoration in a patient.
PubMed: 36237818
DOI: 10.7759/cureus.29043 -
Materials (Basel, Switzerland) Sep 2022Structural health monitoring systems for composite laminates using guided ultrasonic waves become more versatile with the structural integration of sensors. However, the...
Structural health monitoring systems for composite laminates using guided ultrasonic waves become more versatile with the structural integration of sensors. However, the data generated within these sensors have to be transmitted from the laminate to the outside, where polyimide-based printed circuit boards play a major role. This study investigates, to what extent integrated polyimide inlays with applied sensor bodies influence the guided ultrasonic wave propagation in glass fiber-reinforced polymer specimens. For reasons of resource efficiency, narrow specimens are used. Numerical simulations of a damping-free specimen indicate reflections of the S0-mode at the integrated inlay. This is validated experimentally with an air-coupled ultrasonic technique and a 3D laser Doppler vibrometry measurement. The experimental data are evaluated with a method including temporal and spatial continuous wavelet transformations to clearly identify periodically occurring wave packages as edge reflections and distinguish them from possible inlay reflections. However, even when separating in-plane and out-of-plane movements using the 3D measurement, no reflections at the inlays are detected. This leads to the conclusion that polyimide inlays are well suited as substrates for printed circuit boards integrated into fiber-reinforced polymer structures for structural health monitoring, since they do not significantly influence the wave propagation.
PubMed: 36234093
DOI: 10.3390/ma15196752 -
Journal of Conservative Dentistry : JCD 2022Advances in adhesive technologies and escalation in esthetic demands have increased indications for tooth-colored, partial coverage restorations. Recently, material... (Review)
Review
BACKGROUND
Advances in adhesive technologies and escalation in esthetic demands have increased indications for tooth-colored, partial coverage restorations. Recently, material knowledge has evolved, new materials have been developed, and no systematic review has answered the question posed by practitioners: Is the clinical efficacy of resin or ceramic better, for inlay, onlay, and overlay in the long run?
AIM
The aim of this systematic review and meta-analysis was to evaluate the clinical performance of ceramic and resin inlays, onlays, and overlays and to identify the complication types associated with the main clinical outcomes.
MATERIALS AND METHODS
Two reviewers (VN and AJ) searched PubMed, Embase, and Cochrane Central registry of controlled trials for published articles between 1983 and 2020 conforming to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines for systematic reviews. Only clinical studies which met the following criteria were included (1) studies regarding ceramic and resin inlays, onlays, and overlays were included; (2) randomized controlled trials, retrospective or prospective studies conducted in humans; (3) studies with a dropout rate <50% 4) studies with a follow-up higher than 5 years.
RESULTS
Of 1718 articles, 21 articles were selected. At 5 years, the estimated survival rates for resin ( = 129) was 86%, feldspathic porcelain ( = 1048) was 90%, and glass ceramic ( = 2218) was 92%; at 10 years, the survival of resin was 75% ( = 115), feldspathic porcelain was 91% ( = 1829), and glass ceramic was 89% ( = 1075).
CONCLUSION
The meta-regression indicated that ceramic partial coverage restorations (feldspathic porcelain and glass-ceramic) outperformed resin partial coverage restorations both at 5-year and 10-year follow-up. When compared between ceramic types, glass ceramics outperformed feldspathic porcelain at 5 years' follow-up and feldspathic porcelain outperformed glass ceramics at 10 years' follow-up. The failures were mostly due to fractures (6.2%), endodontic problems (3%), secondary caries (1.7%), and debonding which was 0.9%.
PubMed: 36187858
DOI: 10.4103/jcd.jcd_184_22 -
Cureus Aug 2022Marginal accuracy is one of the serious factors that play a key role in the overall success of prostheses. It is openly associated with marginal activities of...
BACKGROUND
Marginal accuracy is one of the serious factors that play a key role in the overall success of prostheses. It is openly associated with marginal activities of microorganisms, which may develop micro-leakage and other problems. Therefore, this in vitro study was conducted to assess marginal accuracies in copings fabricated with two different alloys used in fixed partial dentures.
MATERIALS AND METHODS
Two popularly used metal alloys, Mealloy (nickel-chromium alloy) (Dentsply India Pvt. Ltd., New Delhi, India) and Supranium (nickel-chromium alloy) (Bombay Precision Alloy Inc., Mumbai, India), were studied. Group 1 has 20 copings of Mealloy; group 2 also has 20 copings of Supranium. Blue inlay wax was used for wax pattern fabrication. All copings were cast and made by similar casting techniques. After adequate seating of copings on metal dies, the marginal difference was assessed under a stereomicroscope at typical intensification. All measurements were noticed and converted to the nearest micron. For each coping sample, four measurements were recorded; however, the means of all four surfaces were taken into account for further analysis.
RESULTS
All interrelated data was processed by statistical analysis using the Statistical Package for the Social Sciences (SPSS) software version 22.0 (IBM Corp., Armonk, NY, USA). The overall mean marginal gap of the samples of group 1 was higher than group 2. For group 1 coping samples, a maximum mean marginal gap of 43.379 was noticed at the buccal surface of the copings. P-value computation revealed non-significant values (0.60). For group 2 coping samples, a maximum mean marginal gap of 41.218 was found at the buccal surface of the copings. The measured value was 41.218. One-way ANOVA analysis showed that the degree of freedom was 132.13 for cumulative comparison, while it was 2.930 and 6.837 for calculations between groups and within groups, respectively. Two-sample t-test assessments revealed a p-value of 0.001 (significant) for group 1 and a p-value of 0.810 (non-significant) for group 2.
CONCLUSION
The marginal space at the margin of the metal coping and the die was minimum for Supranium and maximum for Mealloy. Also, highly significant values were also identified for the metal samples of Supranium. Additionally, the selection of the perfect metal alloy should be entirely dependent on operator skills and clinical decision-making.
PubMed: 36158416
DOI: 10.7759/cureus.28217 -
Polymers Sep 2022An integrable sensor inlay for monitoring crack initiation and growth inside bondlines of structural carbon fiber-reinforced plastic (CFRP) components is presented. The...
An integrable sensor inlay for monitoring crack initiation and growth inside bondlines of structural carbon fiber-reinforced plastic (CFRP) components is presented. The sensing structures are sandwiched between crack-stopping poly(vinyliden fluoride) (PVDF) and a thin reinforcing polyetherimide (PEI) layer. Good adhesion at all interfaces of the sensor system and to the CFRP material is crucial, as weak bonds can counteract the desired crack-stopping functionality. At the same time, the chosen reinforcing layer must withstand high strains, safely support the metallic measuring grids, and possess outstanding fatigue strength. We show that this robust sensor system, which measures the strain at two successive fronts inside the bondline, allows to recognize cracks in the proximity of the inlay regardless of the mechanical loads. Feasibility is demonstrated by static load tests as well as cyclic long-term fatigue testing for up to 1,000,000 cycles. In addition to pure crack detection, crack distance estimation based on sensor signals is illustrated. The inlay integration process is developed with respect to industrial applicability. Thus, implementation of the proposed system will allow the potential of lightweight CFRP constructions to be better exploited by expanding the possibilities of structural adhesive bonding.
PubMed: 36145961
DOI: 10.3390/polym14183816 -
Journal of Pharmacy & Bioallied Sciences Jul 2022The extensively damaged teeth can be treated with the inlay and onlay. The ceramic inlays and onlays can be prescribed for the esthetic needs of the patient. Hence in...
INTRODUCTION
The extensively damaged teeth can be treated with the inlay and onlay. The ceramic inlays and onlays can be prescribed for the esthetic needs of the patient. Hence in our study, we aim to evaluate clinically the outcomes of the ceramic inlays and onlays for the posterior teeth.
MATERIALS AND METHODS
We piloted a retrospective analytical study from the departmental records. We included 70 patients who had a total of 160 ceramic inlays and onlays prepared between the years 2010-2020. The survival and the failure rates were noted and compared using the "Kruskal-Wallis H statistics and the Chi-square tests" deliberating < 0.05 as significant.
RESULTS
The mean survival was 6.1 ± 1.8 years. The success rate was 92.21% and the failure was 7.6%. Significant variation was seen with the survival rate between the vital and nonvital teeth and between the molars and premolars.
CONCLUSIONS
The ceramic inlays and onlays were performed successfully in the posterior teeth with a high survival rate and very low failure.
PubMed: 36110720
DOI: 10.4103/jpbs.jpbs_776_21 -
Journal of Pharmacy & Bioallied Sciences Jul 2022The aim of this study is to evaluate and compare the sealing ability of a new resin cement which was undergoing trial with other three luting cements.
AIMS
The aim of this study is to evaluate and compare the sealing ability of a new resin cement which was undergoing trial with other three luting cements.
SETTINGS AND DESIGN
study.
SUBJECTS AND METHODS
Forty extracted intact human premolars were selected and standardized class 5 preparations for inlays were done at cementoenamel junction of buccal surfaces and direct composite inlay was fabricated. The samples were randomly grouped into 4: Group I luted with Rely X ARC resin cement, Group II with DCRC-10, a new indigenously developed resin cement, Group III with FujiCEM, and Group IV with zinc phosphate. After 24 h storage, samples were thermocycled and immersed in basic fuchsine dye. The longitudinal sections were assessed under a stereomicroscope for microleakage using graded criteria.
STATISTICAL ANALYSIS USED
To analyze leakage scores among four groups and between enamel and dentin/cementum margins, Kruskal-Wallis nonparametric test and the Mann-Whitney test at < 0.05 were used.
RESULTS
The dye penetration at cementum/dentin margins showed a statistically significant difference among four groups ( < 0.001). Adhesive luting cements produced lesser leakage scores at both margins than those cemented with zinc phosphate.
CONCLUSIONS
The indigenously developed resin cement (DCRC-10, Group II) is comparable to that of Group I (RelyX ARC) in terms of its luting efficiency.
PubMed: 36110690
DOI: 10.4103/jpbs.jpbs_756_21