Dental Materials最新文献

{"title":"Exploring the optical behavior and relative translucency parameter of CAD-CAM resin-based composites, polymer-infiltrated ceramic network, and feldspar porcelain","authors":"Bruno Arruda Mascaro ,&nbsp;Maria Tejada-Casado ,&nbsp;Renata Garcia Fonseca ,&nbsp;José Maurício dos Santos Nunes Reis ,&nbsp;María M. Pérez","doi":"10.1016/j.dental.2024.09.007","DOIUrl":"10.1016/j.dental.2024.09.007","url":null,"abstract":"<div><h3>Objectives</h3><div>To evaluate and compare the optical properties and relative translucency parameter of CAD-CAM restorative materials.</div></div><div><h3>Methods</h3><div>Four CAD-CAM materials were evaluated: Lava Ultimate (LU), Grandio Blocs (GB), VITA Enamic (VE), and VITA Mark II (VM). Disk-shaped samples in shade A2-HT were prepared (n = 10) and polished to 1.00 ± 0.01 mm of thickness. Scattering (S), absorption (K), albedo (<em>a</em>) coefficient, transmittance (T%), light reflectivity (RI), infinite optical thickness (<em>X</em>_∞), and radiative transfer coefficients (<em>μ</em>_<em>a</em>, and <em>μ</em>′_<em>S</em><em>)</em> were calculated using Kubelka-Munk method and Thennadil's semi-empirical approach. Root Mean Square Error (<em>RMSE</em>) and Goodness of Fit (GFC) were used as performance optical behavior. Translucency differences were evaluated using the relative translucency parameter (RTP₀₀) and 50:50 % translucency perceptibility and acceptability thresholds (TPT₀₀ and TAT₀₀).</div></div><div><h3>Results</h3><div>The spectral distribution of S, K, T%, RI, and <em>X</em>_∞ was wavelength-dependent. GFC and <em>RMSE</em> values indicated good spectral behavior matches and good comparative spectral values for RI in LU-GB, LU-VE, and GB-VE, and for K in VE-VM. VM displayed the highest scattering values across the wavelengths, while VE and VM showed lower absorption at shorter wavelengths. LU and GB had the highest transmittance. The <em>X</em>_∞ values indicated that all 1.0 mm thick materials could be influenced by the background. No good spectral match and no good comparative spectral values were found between CAD-CAM materials and anterior bovine maxillary specimens. VM had the lowest RTP₀₀ values with perceptible and unacceptable differences compared to CAD-CAM materials evaluated.</div></div><div><h3>Significance</h3><div>Understanding the optical behavior of different CAD-CAM materials was essential for guiding clinicians in material selection and optimizing their clinical performance. The findings confirm that the different compositions and microstructure impact the optical properties and translucency of CAD-CAM restorative materials.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 1954-1961"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142338150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polymer vesicles for the delivery of inhibitors of cariogenic biofilm","authors":"Parmanand Ahirwar ,&nbsp;Veronika Kozlovskaya ,&nbsp;Piyasuda Pukkanasut ,&nbsp;Pavel Nikishau ,&nbsp;Sarah Nealy ,&nbsp;Gregory Harber ,&nbsp;Suzanne M. Michalek ,&nbsp;Linto Antony ,&nbsp;Hui Wu ,&nbsp;Eugenia Kharlampieva ,&nbsp;Sadanandan E. Velu","doi":"10.1016/j.dental.2024.09.006","DOIUrl":"10.1016/j.dental.2024.09.006","url":null,"abstract":"<div><h3>Objectives</h3><div>The goal of this study is to develop a novel drug delivery platform for the pH-responsive delivery of biofilm inhibitors as a potential avenue to prevent and treat dental caries.</div></div><div><h3>Methods</h3><div>Biofilm and growth inhibition assays were performed in polystyrene microtiter 96-well plates. Docking analysis was performed using the reported GtfB + HA5 co-crystal structure (PDB code: 8fg8) in SeeSAR 13.0.1 software. Polymersome vesicles were assembled from poly(N-vinylpyrrolidone)₈-<em>block</em>-poly(dimethylsiloxane)₆₄-<em>block</em>-poly(N-vinylpyrrolidone)₈ (PVPON₈-PDMS₆₄-PVPON₈) triblock copolymer using a nanoprecipitation method. Microbiome analysis of biofilm inhibitors and the <em>in vivo</em> drug release and antivirulence activities of polymersome encapsulated inhibitors have been carried out in a <em>S. mutans</em> induced rat caries model.</div></div><div><h3>Results</h3><div>Biofilm inhibitors for HA5 and HA6 have shown species-specific selectivity towards <em>S. mutans</em> and the ability to preserve the oral microbiome in a <em>S. mutans</em> induced dental caries model. The inhibitors were encapsulated into pH-responsive block copolymer vesicles to generate polymersome-encapsulated biofilm inhibitors, and their biofilm and growth inhibitory activities against <em>S. mutans</em> and representative strains of oral commensal streptococci have been assessed. A 4-week treatment of <em>S. mutans</em> UA159 infected gnotobiotic rats with 100 µM of polymersome-encapsulated biofilm inhibitor, PEHA5 showed significant reductions in buccal, sulcal, and proximal caries scores compared to an untreated control group.</div></div><div><h3>Significance</h3><div>Taken together, our data suggests that the biofilm-selective therapy using the polymersome-encapsulated biofilm inhibitors is a viable approach for the prevention and treatment of dental caries while preserving the oral microbiome.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 1937-1953"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142338152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct colour printing on zirconia using 222 nm UV-C photons.","authors":"Xuedong Bai, Mengxiao Xu, Shixin Jin, Edmond H N Pow, Yanning Chen, James K H Tsoi","doi":"10.1016/j.dental.2024.10.019","DOIUrl":"https://doi.org/10.1016/j.dental.2024.10.019","url":null,"abstract":"<p><strong>Objectives: </strong>To proof the feasibility of direct colour printing on 3Y-TZP using 222 nm UV-C through investigating the degree and durability of the colour changes, and testifying whether surface, mechanical and biological properties are influenced by the treatment.</p><p><strong>Methods: </strong>222 nm UV-C light (Irradiance: 1.870 mW/cm²) was used to treat 3Y-TZP for durations from 15 min to 24 h. ΔE*, TP, crystalline structure, surface morphology, S_a, BFS and biological activities were investigated before and after irradiation. SPSS 28.0 was used for statistical analysis (α = 0.05).</p><p><strong>Results: </strong>222 nm UV-C irradiation was capable to shade white 3Y-TZP into tooth colours. With the increase of ΔE*, TP decreased, such that the longer the irradiation time, the higher the ΔE* (logarithmic relationship) and lower the TP. Despite the induced optical changes being prone to fade, the process can be predicted by inversely proportional relationships between ΔE*, TP and the testing points. The treated surface exhibited enhanced hydrophilicity, while the recovery phenomenon was observed. Other properties were not altered by the treatment.</p><p><strong>Significance: </strong>This is the seminal study demonstrating the feasibility of direct colour printing on 3Y-TZP using 222 nm UV-C. The new relationship between the colour centre and E_g of 3Y-TZP was established, whereas the induced optical changes were stabilised after a certain period and were highly predictable by controlling the irradiation periods. The irradiation was only correlated to the electron excitation and oxygen vacancies, and would not lead to any changes of other properties. A simple, safe and promising approach to achieve satisfactory colours on 3Y-TZP in clinical practice can be developed.</p>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":" ","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142563538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of dental cements derived from mixtures of highly reactive ionomer glasses and bottle glass: Cement manipulation, mechanical, fluoride ion releasing, radiopaque and setting properties","authors":"Olivia Awino Osiro ,&nbsp;Melissa Tiskaya ,&nbsp;Saroash Shahid ,&nbsp;Robert Graham Hill","doi":"10.1016/j.dental.2024.09.013","DOIUrl":"10.1016/j.dental.2024.09.013","url":null,"abstract":"<div><h3>Objectives</h3><div>To evaluate the mechanical properties, fluoride release, radiopacity, and setting characteristics of dental cements derived from highly reactive ionomer glasses and bottle glass mixtures.</div></div><div><h3>Methods</h3><div>Two highly reactive glass series, LG99 and LG117, were synthesized, milled, sieved, and characterized using XRD and laser particle size analysis. These glasses were mixed with predetermined ratios of ground bottle glass, poly(acrylic acid), and aqueous tartaric acid to form glass ionomer cements. The cements' working time (WT), setting time (ST), fluoride release, radiopacity, compressive strength (CS), and elastic modulus (EM) were evaluated. Mean differences in CS were analyzed using multivariate ANOVA with Tukey’s post hoc test at p = 0.05.</div></div><div><h3>Results</h3><div>The WT and ST for both groups ranged from 1.5 to 2.5 min. LG99 series cements showed significantly higher CS (∼65 MPa) and EM (∼2 GPa) than LG117 series (p &lt; 0.05). Both series showed similar fluoride release profiles, peaking at 1.2 mmol/L at 28 days. Radiopacity for LG99 ranged from 0.97 to 1.34, while LG117 ranged from 0.60 to 0.95. Solid state ²⁷Al magic-angle spinning-nuclear magnetic resonance (MAS NMR) confirmed the presence of Al(IV) and Al(VI), indicating setting completion by one day for both series. Bottle glass showed a chemical shift at 55.8 ppm, overlapping with LG99′s Al(IV) signal. The ¹⁹F MAS NMR spectra revealed Al-F and F-Sr(n) species in all glasses, with LG117 forming CaF₂ after one day in deionized water.</div></div><div><h3>Conclusion</h3><div>Mixtures of highly reactive ionomer glass and bottle glass produced cements with satisfactory properties for dental applications. Further research is needed to optimize their formulation and properties.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 1981-1990"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142338149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Longevity and risk factors of CAD-CAM manufactured implant-supported all-ceramic crowns - A prospective, multi-center, practice-based cohort study","authors":"R.J. Wierichs ,&nbsp;E.J. Kramer ,&nbsp;B. Reiss ,&nbsp;A. Roccuzzo ,&nbsp;C. Raabe ,&nbsp;B. Yilmaz ,&nbsp;S. Abou-Ayash","doi":"10.1016/j.dental.2024.09.008","DOIUrl":"10.1016/j.dental.2024.09.008","url":null,"abstract":"<div><h3>Objectives</h3><div>The aim of this prospective, multi-center, practice-based cohort study was to analyze factors associated with the success of implant supported all-ceramic single-unit crowns, made by computer-aided-design/computer-aided-manufacturing (CAD-CAM).</div></div><div><h3>Methods</h3><div>All-ceramic crowns placed in a private practice-based research network (Ceramic Success Analysis, AG Keramik) were analyzed. Data from 567patients with CAD-CAM implant supported all-ceramic crowns placed between 2008–2023 by 54dentists were evaluated. Firstly, all crowns with at least one follow-up control were included (n = 907). Secondly, all crowns being followed up for ≥ 5years and all failures were included (n = 151). At the latest follow-up visit, crowns were considered as successful (not failed) if they were still in function without the need for additional therapy. Multi-level Cox proportional hazards models were used to evaluate the association between a range of predictors and time of success.</div></div><div><h3>Results</h3><div>Within a mean follow-up period (SD) of 2.5 (2)years (first scenario) and 6.2 (1.2)years (second scenario) [maximum:12years], 27crowns failed (annual failure rate [AFR]:0.74 %). The main failure types were decementation, (n = 11), fracture of the ceramic (n = 4) or Ti-Base (n = 4). In 5-year-scenario, crowns fabricated in the laboratory had 26times lower failure rate than those fabricated chairside (95 %CI:0.0–0.7;p = 0.038). Furthermore, the use of a silane (HR:0.051;95 %CI:0.0–0.5;p = 0.014) and etching of the ceramic (HR:0.053;95 %CI:0.0–0.8;p = 0.035) resulted in a significantly higher risk for failure than their non-use.</div></div><div><h3>Significance</h3><div>For CAD-CAM manufactured implant supported all-ceramic crowns, high success rates were found in up to 12-year evaluation. Furthermore, after 5years, no patient-or implant-level factors, but operative-level factor (i.e.fabrication method, use of silane/etching) were significantly associated with failure.</div><div>The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00020271).</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 1962-1969"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142338151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antimicrobial adhesive self-healing hydrogels for efficient dental biofilm removal from periodontal tissue","authors":"Han Sol Kim ,&nbsp;Minkyoung Kim ,&nbsp;Youngjoon Kim ,&nbsp;Hyun Ho Shin ,&nbsp;Sang-woo Lee ,&nbsp;Ji Hyun Ryu","doi":"10.1016/j.dental.2024.09.012","DOIUrl":"10.1016/j.dental.2024.09.012","url":null,"abstract":"<div><h3>Objectives</h3><div>Oral biofilms, including pathogens such as <em>Porphyromonas gingivalis</em>, are involved in the initiation and progression of various periodontal diseases. However, the treatment of these diseases is hindered by the limited efficacy of many antimicrobial materials in removing biofilms under the harsh conditions of the oral cavity. Our objective is to develop a gel-type antimicrobial agent with optimal physicochemical properties, strong tissue adhesion, prolonged antimicrobial activity, and biocompatibility to serve as an adjunctive treatment for periodontal diseases.</div></div><div><h3>Methods</h3><div>Phenylboronic acid-conjugated alginate (Alg–PBA) was synthesized using a carbodiimide coupling agent. Alg–PBA was then combined with tannic acid (TA) to create an Alg–PBA/TA hydrogel. The composition of the hydrogel was optimized to enhance its mechanical strength and tissue adhesiveness. Additionally, the hydrogel’s self-healing ability, erosion and release profile, biocompatibility, and antimicrobial activity against <em>P. gingivalis</em> were thoroughly characterized.</div></div><div><h3>Results</h3><div>The Alg–PBA/TA hydrogels, with a final concentration of 5 wt% TA, exhibited both mechanical properties comparable to conventional Minocycline gel and strong tissue adhesiveness. In contrast, the Minocycline gel demonstrated negligible tissue adhesion. The Alg–PBA/TA hydrogel also retained its rheological properties under repeated 5 kPa stress owing to its self-healing capability, whereas the Minocycline gel showed irreversible changes in rheology after just one stress cycle. Additionally, Alg–PBA/TA hydrogels displayed a sustained erosion and TA release profile with minimal impact on the surrounding pH. Additionally, the hydrogels exhibited potent antimicrobial activity against <em>P. gingivalis</em>, effectively eliminating its biofilm without compromising the viability of MG-63 cells.</div></div><div><h3>Significance</h3><div>The Alg–PBA/TA hydrogel demonstrates an optimal combination of mechanical strength, self-healing ability, tissue adhesiveness, excellent biocompatibility, and sustained antimicrobial activity against <em>P. gingivalis</em>. These attributes make it superior to conventional Minocycline gel. Thus, the Alg–PBA/TA hydrogel is a promising antiseptic candidate for adjunctive treatment of various periodontal diseases.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 1970-1980"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142338146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emerging nanozyme therapy incorporated into dental materials for diverse oral pathologies","authors":"Menghan Zhao ,&nbsp;Jin Yang ,&nbsp;Jiangyi Liang ,&nbsp;Ruixin Shi ,&nbsp;Wei Song","doi":"10.1016/j.dental.2024.07.025","DOIUrl":"10.1016/j.dental.2024.07.025","url":null,"abstract":"<div><h3>Objective</h3><div>Nanozyme materials combine the advantages of natural enzymes and artificial catalysis, and have been widely applied in new technologies for dental materials and oral disease treatment. Based on the role of reactive oxygen species (ROS) and oxidative stress pathways in the occurrence and therapy of oral diseases, a comprehensive review was conducted on the methods and mechanisms of nanozymes and their dental materials in treating different oral diseases.</div></div><div><h3>Methods</h3><div>This review is based on literature surveys from PubMed and Web of Science databases, as well as reviews of relevant researches and publications on nanozymes in the therapy of oral diseases and oral tumors in international peer-reviewed journals.</div></div><div><h3>Results</h3><div>Given the unique function of nanozymes in the generation and elimination of ROS, they play an important role in the occurrence, development, and treatment of different oral diseases. The application of nanozymes in dental materials and oral disease treatment was introduced, including the latest advances in their use for dental caries, pulpitis, jaw osteomyelitis, periodontitis, oral mucosal diseases, temporomandibular joint disorders, and oral tumors. Future approaches were also summarized and proposed based on the characteristics of these diseases.</div></div><div><h3>Significance</h3><div>This review will guide biomedical researchers and oral clinicians to understand the mechanisms and applications of nanozymes in the therapy of oral diseases, promoting further development in the field of dental materials within the oral medication. It is anticipated that more suitable therapeutic agents or dental materials encapsulating nanozymes, specifically designed for the oral environment and simpler for clinical utilization, will emerge in the forthcoming future.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 1710-1728"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141896287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparison of different cleaning approaches for blood contamination after curing universal adhesives on the dentine surface","authors":"Ting Liu ,&nbsp;Haifeng Xie ,&nbsp;Chen Chen","doi":"10.1016/j.dental.2024.07.035","DOIUrl":"10.1016/j.dental.2024.07.035","url":null,"abstract":"<div><h3>Objective</h3><div>This study compared the effectiveness of various cleaning approaches, including spray rinsing, repreparing with diamond burs, and using phosphoric acid or sodium hypochlorite alone or with polyphenols (resveratrol or myricetin), in removing blood contamination from the dentine after adhesive light-curing.</div></div><div><h3>Methods</h3><div>The contact angles of the treated surfaces were measured and scanning electron microscopy/ energy dispersive X-ray spectroscopy observation was performed. The bond strength and nanoleakage were assessed, and in situ zymography was performed before and after aging. Interactions between matrix metalloproteinase (MMP)−9 and polyphenols were evaluated using molecular dynamics and rhMMP-9 inhibition analyses. The destruction of sodium hypochlorite on collagen and the resistance of polyphenols-treated dentine collagen to enzymolysis were evaluated using the hydroxyproline (HYP) assay. The effect of polyphenols on dentine collagen crosslinking was assessed by Fourier Transform Infrared Spectroscopy.</div></div><div><h3>Results</h3><div>The repreparation group had the lowest contact angle compared to the other groups. The spray rinsing group had the lowest bond strength and highest amounts of nanoleakage. Cleaning with phosphoric acid or sodium hypochlorite alone removed the blood contaminants and parts of the adhesive; moreover, applying polyphenols further improved the bond strength and decreased nanoleakage and MMP activity after aging. Both polyphenols inhibited rhMMP-9 activity and promoted collagen crosslinking. Sodium hypochlorite showed the maximum HYP release when used alone, which was decreased after adding polyphenols.</div></div><div><h3>Significance</h3><div>Phosphoric acid or sodium hypochlorite cleaning can remove blood contamination from the dentine surface after adhesive curing, and the addition of polyphenols can improve the durability of dentine bonding.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 1786-1797"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141915652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fretting-corrosion at the Implant–Abutment Interface Simulating Clinically Relevant Conditions","authors":"Yani Sun ,&nbsp;Apurwa Shukla ,&nbsp;Remya Ampadi Ramachandran ,&nbsp;Hemalatha Kanniyappan ,&nbsp;Bin Yang ,&nbsp;Rand Harlow ,&nbsp;Stephen D. Campbell ,&nbsp;Ghadeer Thalji ,&nbsp;Mathew Mathew","doi":"10.1016/j.dental.2024.08.007","DOIUrl":"10.1016/j.dental.2024.08.007","url":null,"abstract":"<div><h3>Objective</h3><div>Implant treatment is provided to individuals with normal, idealized masticatory forces and also to patients with parafunctional habits such as grinding, clenching, and bruxing. Dental erosion is a common increasing condition and is reported to affect 32 % of adults, increasing with age. This oral environment is conducive to tribocorrosion and the potential loss of materials from the implant surfaces and interfaces with prosthetic components. Although several fretting-corrosion studies have been reported, until now, no study has simulated clinically relevant micromotion. Therefore, our aim is to investigate fretting-corrosion using our new micro-fretting corrosion system, simulating clinical conditions with 5 µm motion at the implant-abutment interface under various occlusal loads and acidic exposures.</div></div><div><h3>Methods</h3><div>We simulated four conditions in an oral environment by varying the contact load (83 N and 233 N) and pH levels (3 and 6.5). The commonly used dental implant material, Grade IV titanium, and abutment material Zirconia (ZrO₂)/ Grade IV titanium were selected as testing couple materials. Artificial saliva was employed to represent an oral environment. In addition, a standard tribocorrosion protocol was followed, and the pin was controlled to oscillate on the disk with an amplitude of 5 <span><math><mi>μ</mi></math></span>m during the mastication stage. After the testing, 3D profilometry and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) were utilized to analyze the worn surfaces. Inductively coupled plasma mass spectrometry (ICP-MS) was also used to measure the metal ion release.</div></div><div><h3>Results</h3><div>Energy ratios were below 0.2, indicating a fretting regime of partial slip for all groups. Open-circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) were analyzed to compare the electrochemical behavior among groups. As a result, corrosive damage was observed to be more in the Ti4- Ti4 groups than in Zr-Ti4 ones, whereas more mechanical damage was found in the Zr-Ti4 groups than in the Ti4-Ti4 groups. Possible mechanisms were proposed in the discussion to explain these findings.</div></div><div><h3>Significance</h3><div>The results observed from this study might be helpful to clinicians with implant selection. For example, for patients with bruxism, a titanium implant paired with a titanium abutment may be preferable, while patients with GERD may benefit more from a titanium implant paired with a zirconia abutment.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 1823-1831"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142034736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of print orientation and graphene nanoplatelets on biaxial flexural strength and cytotoxicity of a 3D printable resin for occlusal splints","authors":"Klara Janjić ,&nbsp;Angelika Valentova ,&nbsp;Sonia Arellano ,&nbsp;Angelika Unterhuber ,&nbsp;Arno Krause ,&nbsp;Gunpreet Oberoi ,&nbsp;Ewald Unger ,&nbsp;Hassan Ali Shokoohi Tabrizi ,&nbsp;Andreas Schedle","doi":"10.1016/j.dental.2024.07.031","DOIUrl":"10.1016/j.dental.2024.07.031","url":null,"abstract":"<div><h3>Objectives</h3><div>3D printing found its way into various medical applications and could be particularly beneficial for dentistry. Currently, materials for 3D printing of occlusal splints lack mechanical strength compared to polymethyl methacrylate (PMMA) used for standard milling of occlusal splints. It is known that print orientation and graphene nanoplatelets (GNP) can increase biaxial strength in a variety of materials. Thus, the aim of this study was to assess if adjustment of print orientation and addition of GNP improve biaxial strength and if they affect cytotoxicity of a 3D printable resin for occlusal splints.</div></div><div><h3>Methods</h3><div>Specimens were printed vertically and horizontally with a stereolithography (SLA) printer and multilayered GNP powder was added to the resin at different concentrations. Printed specimens were characterized by Raman spectroscopy, optical profilometer analysis and scanning electron microscopy. Biaxial strength was evaluated by biaxial flexural testing. Cytotoxicity of specimens on L929 and gingival stromal cells (GSC) was assessed by the toxdent test, the resazurin-based toxicity assay and live-dead staining.</div></div><div><h3>Results</h3><div>Horizontally printed specimens showed significantly higher biaxial strength and lower deformation. GNP did not improve biaxial strength and material deformation of 3D-printed resins. None of the specimens were cytotoxic to L929 cells or GSC.</div></div><div><h3>Significance</h3><div>Print orientation in SLA printing has a significant impact on biaxial strength and material deformation. 3D printable materials can reach comparable or even improved biaxial strength compared to PMMA when using the optimal print orientation while GNP has no beneficial effects on the biaxial strength of resins for 3D printing of occlusal splints.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 1742-1752"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141905295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}