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The International Journal of... Nov 2023To assess the influence of the bonding system and restorative material on the marginal integrity and pull-off forces of monolithic all-ceramic crowns bonded to titanium...
PURPOSE
To assess the influence of the bonding system and restorative material on the marginal integrity and pull-off forces of monolithic all-ceramic crowns bonded to titanium base (ti-base) abutments.
MATERIALS AND METHODS
A total of 108 ti-bases were sandblasted and divided into nine experimental groups (n = 12) according to the combination of crown material (polymer-infiltrated ceramic-network [PI], lithium-disilicate [LD], and zirconia [ZI]) and bonding system (Multilink Hybrid-Abutment [MH], Panavia V5 [PV], RelyX Ul5mate [RU]) with the respective primers. After bonding the crowns to the ti-base abutments, the restorations were screw-retained on implants and thermomechanically aged (1,200,000 cycles, 49 N, 1.67 Hz, 5 to 55°C). Marginal integrity and bonding failures were evaluated under a light microscope, and pull-off forces (N) were calculated. Chi-square tests for marginal integrity as well as one-way and two-way ANOVA statistical tests for pull-off forces were applied (a = .05).
RESULTS
PI presented higher marginal integrity than LD (P = .023). Bonding system PV revealed higher marginal integrity than MH (P =.005) and RU (P =.029). Differences in pull-off forces were found between restorative material and resin cements (P < .001), with the highest values for ZI + RU (598 ± 192 N), PI + PV (545 ± 114 N), LD + MH (532 ± 116 N), and PI + RU (528 ± 81 N). Specimens with marginal integrity revealed higher pull-off forces than those with alteration (P = .006). Specimens presenting bonding failures (micromovements) showed lower pull-off forces than those without bonding failures (P < .001).
CONCLUSIONS
The tested CAD/CAM materials show favorable bonding performances with different bonding systems, nevertheless for each restorative material a specific bonding system has to be recommended. Int J Prosthodont 2023;36:e88-e102.
Topics: Titanium; Dental Materials; Crowns; Ceramics; Resin Cements; Materials Testing; Zirconium; Computer-Aided Design; Dental Stress Analysis; Dental Abutments
PubMed: 36288489
DOI: 10.11607/ijp.7576 -
International Dental Journal Aug 2023The aim of this research was to assess the effect of incorporating zein-coated magnesium oxide (zMgO) nanofillers to resin-based composite on the internal adaptation of...
OBJECTIVE
The aim of this research was to assess the effect of incorporating zein-coated magnesium oxide (zMgO) nanofillers to resin-based composite on the internal adaptation of the restorations using cross-polarisation optical coherence tomography (CP-OCT).
METHODS
Thirty noncarious human molar teeth were used. Class V cavities (3 × 5 mm) were prepared on the buccal and lingual surfaces of each tooth. Clearfil SE Bond 2 was applied to all the cavities and then the teeth were divided into 3 groups (n = 10) as follows: group 1-restored with N-Flow composite; group 2 and group 3-restored with N-Flow composite mixed with different zMgO nanoparticle concentrations (0.3% and 0.5% by weight, respectively) and then light cured using an LED curing device. Specimens were examined for interfacial adaptation examination under CP-OCT. Characterisation of the dental composite incorporating zMgO was done by Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM). Results were analysed with Kruskall-Wallis test followed by Mann-Whitney U test, at a significance level of P < .05.
RESULTS
XRD spectra exhibited the sharp peaks of zMgO in the composite enhanced with zMgO nanoparticles. FESEM analysis showed a uniform distribution of the zMgO nanoparticles in the composite and FTIR illustrated no change in the spectra. The gap percentage along the cavity floor was significantly lower in groups 2 and 3 in comparison to group 1 (P < .05). Also there was a significant difference in gap percentages between groups 2 and 3 (P < .05), with group 3 showing the lowest gap percentage.
CONCLUSIONS
The incorporation of 0.3% and 0.5% zMgO nanoparticles in flowable composite assists in improving the internal adaptation of the composite to the tooth surface.
Topics: Humans; Dental Restoration, Permanent; Dental Cavity Preparation; Composite Resins; Dental Materials; Resin Cements; Molar; Anti-Infective Agents; Dental Marginal Adaptation; Dental Leakage; Materials Testing
PubMed: 36549967
DOI: 10.1016/j.identj.2022.11.004 -
Journal of the Mechanical Behavior of... Feb 2024Dental zirconia ceramics, widely employed in dentistry for their biocompatibility and mechanical properties, face challenges in long-term viability within the oral...
Dental zirconia ceramics, widely employed in dentistry for their biocompatibility and mechanical properties, face challenges in long-term viability within the oral cavity. This study focuses on analyzing the electrochemical behavior of a commercial dental zirconia ceramic type in acidic environments. Through extensive electrochemical investigations, including Electrochemical Impedance Spectroscopy (EIS) and cyclic polarization resistance (Cpol), corrosion resistance was assessed. Despite indications of material dissolution, our results demonstrate significant corrosion resistance, as reflected in low corrosion current density (Icorr) values. Notably, the study reveals the development of a protective oxide layer at the ceramic-electrolyte interface, contributing to material stability. XRD analysis confirms the presence of stable crystallographic phases (t-ZrO2) even after exposure to acidic media. Surface characterizations utilizing scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX) affirm minimal surface damage and maintained elemental composition. These findings illuminate the intricate electrochemical behavior of dental zirconia ceramics in challenging environments, underscoring their potential for durable dental restorations. This interdisciplinary research bridges dentistry and materials science, providing valuable insights for optimizing material properties and advancing dental materials and restorative techniques.
Topics: Zirconium; Microscopy, Electron, Scanning; Spectrometry, X-Ray Emission; Ceramics; Surface Properties; Materials Testing; Dental Materials; Dental Porcelain
PubMed: 38109814
DOI: 10.1016/j.jmbbm.2023.106288 -
PloS One 2023The purpose of this study was to assess the effectiveness and practicality of erbium lasers in the removal of ceramic restorations and appliances from natural teeth and...
BACKGROUND
The purpose of this study was to assess the effectiveness and practicality of erbium lasers in the removal of ceramic restorations and appliances from natural teeth and dental implant abutments in clinical practice.
METHODS
A retrospective analysis was conducted, involving 29 clinical cases with a total of 52 abutments requiring the removal of various ceramic restorations. The analysis evaluated the clinical procedures performed, including the type and material of the prosthetic, the type of cement used, laser setting parameters, retrieval time, and retrieval success.
RESULTS
Out of the 52 abutments, 50 were successfully retrieved without causing any damage (>95%) using either an Er,Cr:YSGG laser (N = 6) or an Er:YAG laser (N = 46). In one case, a crown was partially sectioned to prevent any negative impact of laser irradiation on the adhesive strength between the post and tooth, and in another case, a fracture occurred during debonding. The restorations consisted of 13 lithium disilicate and 39 zirconia units, including six veneers, 38 single crowns, and three fixed partial dentures (FPDs). The retrieval time varied depending on the restoration type, material thickness, cement type, retention form/fitting of the abutment and restoration, ranging from 2.25 ±0.61 minutes for veneers, 6.89 ±8.07 minutes for crowns, to 25 ±10 minutes per abutment for FPDs. Removal of a zirconia crown required more time, 7.12±8.91 minutes, compared to a lithium disilicate crown, 5.86 ±2.41 minutes. The debonding time was influenced by the laser settings as well as materials and types of prosthesis.
CONCLUSIONS
Erbium lasers present a safe and effective alternative to invasive methods for removing ceramic restorations, without causing harm to the abutment or prosthesis. Laser-assisted debonding allows for recementation of the restorations during the same appointment, making it a conservative and viable option for ceramic crown retrieval in clinical settings.
Topics: Lasers, Solid-State; Erbium; Retrospective Studies; Crowns; Zirconium; Dental Porcelain; Ceramics; Dental Restoration Failure; Materials Testing
PubMed: 38096248
DOI: 10.1371/journal.pone.0295957 -
Journal of Dentistry Jul 2024With increasing life expectancy and improved preventive measures, teeth are retained longer, leading to a rise in prevalence of root caries lesions (RCL). However,...
OBJECTIVES
With increasing life expectancy and improved preventive measures, teeth are retained longer, leading to a rise in prevalence of root caries lesions (RCL). However, little is known about how dentists manage this condition. The present survey aimed to evaluate the knowledge of Swiss dentists on decision making and management of RCL.
METHOD
The survey evaluated dentists' knowledge, clinical routines, and demographics concerning RCL. Dentists were contacted via email and local newsletters, and 383 dentists from 25 (out of 26) cantons responded. Mann-Whitney U test, χ test, intraclass correlation coefficients, Spearman correlation and Chi Square were used.
RESULTS
The dentists had a mean(SD) working experience of 22.5(12) years. Most dentists correctly classified an inactive (67%) and an active (81%)RCL. Although the inactive lesion did not call for restorative treatments, 61% of the dentist declared they would restore it. From the active lesion,83% would restore it. The invasive treatments leaned toward complete caries excavation with composite resin as preferred restorative material. There were significant correlations between material choice and expected success rates. Among the non-invasive options, oral hygiene instructions and (highly-)fluoridated toothpaste were favored. Most dentists declared having a recall system for such patients, with biannual follow-ups preferred. The dentists' place of education significantly influenced restorative decisions (p < 0.001), while participants' age (≥60years) impacted activity status (p = 0.048) and restorative decisions (p = 0.02).
CONCLUSION
Material preferences for non-invasive or invasive management varied greatly and there were minimal differences in the management of inactive or an active RCL. Moreover, diagnosing active lesions appeared easier than diagnosing inactive ones.
CLINICAL SIGNIFICANCE
Despite diverse material preferences for (non-)invasive treatments, a strong positive correlation existed between the chosen restorative material and its expected 2-year success rate. Moreover, diagnosing active lesions appeared easier than diagnosing inactive ones. The outcome emphasis the need to align guideline recommendations with their application in private dental practices.
Topics: Humans; Root Caries; Male; Practice Patterns, Dentists'; Female; Middle Aged; Surveys and Questionnaires; Adult; Dental Restoration, Permanent; Dentists; Switzerland; Oral Hygiene; Composite Resins; Decision Making; Clinical Decision-Making; Dental Materials; Cariostatic Agents
PubMed: 38762078
DOI: 10.1016/j.jdent.2024.105062 -
BMC Oral Health Nov 2023The successful integration of resin-based dental adhesives significantly impacts restorative dentistry, providing efficient and aesthetically pleasing caries treatments....
BACKGROUND
The successful integration of resin-based dental adhesives significantly impacts restorative dentistry, providing efficient and aesthetically pleasing caries treatments. Among various adhesives, one-step self-etching adhesives (1-SEAs) have gained popularity due to their simplicity and short application time. However, concerns have been raised regarding their bonding performance and marginal adaptation characteristics, which differ from two-step self-etching adhesives (2-SEAs) and three-step etch-and-rinse adhesives. Additionally, light-cured bonding materials may encounter challenges in deep cavities and inaccessible areas, necessitating extended light irradiation time. Autocured bonding materials are a potential solution, but limited comparative studies have been conducted on their performance.
METHODS
In this in vitro study, we evaluated a new autocured universal bonding material (Bondmer Lightless 2) and compared the results with recent light-cured bonding materials. Microshear bond strength (μSBS) tests were performed on 25 human molars using five different combinations of adhesives and composite resins: Bondmer Lightless 2 with Estelite Bulk Fill Flow (BE group), Bondmer Lightless 2 with a prototype composite resin (BO group), Prime&Bond Universal with SDR flow + (PS group), Scotchbond Universal with Filtek Bulk Fill (SF group), and G-Premio Bond with Gracefil BulkFlo (GG group). The bond strengths and failure modes were assessed using a universal testing machine and scanning electron microscope (SEM), respectively. Marginal adaptation was evaluated using swept-source optical coherence tomography (SS-OCT) and confocal laser scanning microscopy (CLSM) on 40 sound bovine maxillary incisors.
RESULTS
The μSBS test showed no significant differences in bond strength among the tested groups. Most failure modes were observed at the bond interface between the adhesive and the dentin. The autocured bonding material demonstrated significantly higher marginal adaptation (SI%) than PS, SF, and GG. The CLSM images corresponded with gaps observed in the SS-OCT images, indicating improved marginal sealing in the autocured group.
CONCLUSIONS
The new autocured universal bonding material exhibited comparable bond strength to a conventional light-cured material while demonstrating a superior marginal adaptation level. This finding suggested that the autocured material could be a valuable alternative, especially when extended light irradiation would pose a challenge. Further clinical studies would be warranted to evaluate the performance of the autocured bonding material in actual restorative dental practice.
Topics: Animals; Cattle; Humans; Dental Cements; Dental Bonding; Composite Resins; Dental Materials; Resin Cements; Dentin; Materials Testing; Tensile Strength
PubMed: 38012568
DOI: 10.1186/s12903-023-03645-0 -
Journal of Esthetic and Restorative... Sep 2023To evaluate gingiva-colored resin-based composites' (GCRBC) color stability and degree of conversion (DC%).
OBJECTIVES
To evaluate gingiva-colored resin-based composites' (GCRBC) color stability and degree of conversion (DC%).
METHODS
Eight discs (8 × 1 mm) of 20 shades of GCRBC were prepared. Color coordinates were measured against a gray background with a calibrated spectroradiometer, CIE D65 illuminant and the CIE 45°/0° geometry at baseline and after 30 days of storage in distilled water, coffee, and red wine. Color differences ( ) between final and baseline conditions were calculated. An ATR-FTIR spectrometer with a diamond tip was used to calculate DC%. The results were analyzed statistically using ANOVA and Tukey post-hoc test. The level of significance was p < 0.05.
RESULTS
DC% and color stability correlated with each other and with the GCRBC brand. DC% ranged between 43% and 96%, highest values correspond to flowable composites. All composites have experienced color changes after immersion in water, wine and coffee. However, the magnitude of the color change has varied widely depending on the immersion medium and the GCRBC. Color changes generated by the wine were, globally, greater than those induced by coffee (p < 0.001) and above the acceptability thresholds.
CONCLUSIONS
The DC% of GCRBCs is sufficient to achieve adequate biocompatibility and physicomechanical properties, but the high susceptibility to staining could compromise aesthetic long-term results.
CLINICAL SIGNIFICANCE
The degree of conversion and the color stability of gingiva-colored resin-based composites correlated with each other. All composites have experienced color changes after immersion in water, wine and coffee. Color changes generated by wine were, globally, greater than those induced by coffee and above the acceptability thresholds that could compromise aesthetic long-term results.
Topics: Coffee; Gingiva; Color; Dental Materials; Composite Resins; Water; Materials Testing; Surface Properties
PubMed: 37403541
DOI: 10.1111/jerd.13082 -
Journal of Dental Research May 2024Dimethacrylate-based chemistries feature extensively as resin monomers in dental resin-based materials due to their distinguished overall performance. However,...
Dimethacrylate-based chemistries feature extensively as resin monomers in dental resin-based materials due to their distinguished overall performance. However, challenges endure, encompassing inadequate mechanical attributes, volumetric shrinkage, and estrogenicity. Herein, we first synthesized a novel resin monomer, 9-armed starburst polyurethane acrylate (NPUA), via the grafting-onto approach. Compared to the primary commercial dental monomer 2,2-bis [p-(2'-hydroxy-3'-methacryloxypropoxy) phenyl] propane (Bis-GMA) (with a viscosity of 1,174 ± 3 Pa·s and volumetric shrinkage of 4.7% ± 0.1%), the NPUA monomer achieves the lower viscosity (158 ± 1 Pa·s), volumetric shrinkage (2.5% ± 0.1%), and cytotoxicity ( < 0.05). The NPUA-based resins exhibit the higher flexural strength, flexural modulus, hardness, and hydrophobicity and lower volumetric shrinkage, water absorption, and solubility compared to the Bis-GMA (70 wt%)/TEGDMA (30 wt%) resins. The NPUA-based composites exhibit significantly higher flexural strength, flexural modulus, and hardness and lower volumetric shrinkage (171.4 ± 3.0 MPa, 12.6 ± 0.5 GPa, 2.0 ± 0.2 GPa, and 3.4% ± 0.2%, respectively) compared to the Bis-GMA group (120.3 ± 4.7 MPa, 9.4 ± 0.7 GPa, 1.5 ± 0.1 GPa, and 4.7% ± 0.2%, respectively; < 0.05). This work presents a viable avenue for augmenting the physicochemical attributes of dental resins.
Topics: Polyurethanes; Materials Testing; Viscosity; Methacrylates; Composite Resins; Flexural Strength; Dental Materials; Bisphenol A-Glycidyl Methacrylate; Polymerization; Polymethacrylic Acids; Hardness; Surface Properties; Acrylic Resins
PubMed: 38549255
DOI: 10.1177/00220345241232312 -
Journal of Esthetic and Restorative... Dec 2023In a suitable condition, it is important to perform any dental restorative procedure using an operatory field isolated. Then, the aim of this study was to compare the... (Review)
Review
INTRODUCTION
In a suitable condition, it is important to perform any dental restorative procedure using an operatory field isolated. Then, the aim of this study was to compare the bond strength of composite restorations to dentin affected by any contamination agent through a systematic review.
METHODS
This systematic review was performed following the PRISMA 2020 guidelines. The literature search was conducted until September 2022 by scanning the following databases: Embase, PubMed, Scielo, Scopus, and Web of Science. Manuscripts evaluated the bond strength of resin-based materials to permanent human dentin contaminated with blood or saliva were selected for full-text review. The risk of bias was assessed by the RoBDEMAT tool.
RESULTS
A total of 3750 papers resulted from the search from all databases. After the full-text reading, a total of 62 articles remained for the qualitative analysis. The contamination agents used were blood, saliva, and hemostatic agents. A great variety of protocols were used to contaminate the dentin surface, and the contamination process occurred in several steps of the bonding process, including before and after the etching process, after the primer application and after the adhesive application. Also, several decontamination procedures were tested, including reapplication of the etching material, rinsing with water, chlorhexidine or sodium hypochlorite and reapplication of the adhesive system.
CONCLUSION
Any contamination with blood or saliva impaired the bond strength of resin-based materials to dentin. Decontamination procedures including water-spray and reapplication of the bonding system could revert the impairment produced by the saliva or blood contamination. The use of hemostatic agents as a method of blood decontamination is not recommended.
CLINICAL SIGNIFICANCE
Clinicians should avoid contamination during a bonding procedure, otherwise, a reduction in the bond quality is expected.
Topics: Humans; Dental Cements; Dentin-Bonding Agents; Resin Cements; Composite Resins; Dental Bonding; Surface Properties; Decontamination; Hemostatics; Dentin; Water; Materials Testing
PubMed: 37395344
DOI: 10.1111/jerd.13078 -
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