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INTRODUCTION: The benefit of pedagogical escape rooms for dental students' stimulation, interest and knowledge strengthening has been suggested by several studies. However, in previous studies, only a few students were evaluated. This study aims to confirm the purpose of this innovative pedagogical tool in terms of learning consolidation and team building from students' perceptions. We directly incorporated an educational escape game into the fundamental academic formation as a practical-work course for fifth-year dental students. MATERIALS AND METHODS: The present escape game focused on 3D printing, whose implementation fit the different steps of an escape game well. This study was conducted in March 2022. All fifth-year dental students (n = 212) were divided into 5-6 student groups to match the conditions of an escape game. Before entering the room, each student had to complete a cross-sectional knowledge true/false test of 8 questions to assess their general level. Additionally, an 18-question appreciation survey was completed when leaving the room. RESULTS: The students perceived the 3D-printing escape game to be relevant and especially expressed the benefit of being part of a team to exchange and build knowledge. These results suggest knowledge strengthening. The instructional benefit of this process seemed to exceed its mere fun and appealing aspect. CONCLUSION: Our results with a large number of students showed that, from the students' perception, the educational escape game significantly improved knowledge and team-building. It created a supportive learning environment and increased students' motivation. It can provide a fun and effective way to diversify instruction.
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Educação em Odontologia , Impressão Tridimensional , Educação em Odontologia/métodos , Humanos , Estudantes de Odontologia/psicologia , Estudos TransversaisRESUMO
OBJECTIVES: To measure the degree of conversion (DC) of different 3D printing resins used for splints or orthodontic appliances under different postpolymerization conditions. MATERIALS AND METHODS: Five 3D-printed photopolymer resins were studied. Each resin was analyzed in liquid form (n = 15), and then cylindrical specimens (n = 135) were additively manufactured and postcured with Form Cure (Formlabs) at different times (10, 60, and 90 min) and temperatures (20 °C, 60 °C, and 80 °C). The DC of each specimen was measured with Fourier transform infrared spectroscopy (FTIR). The data were statistically analyzed using a 3-way ANOVA followed by Tukey's post hoc test. RESULTS: The time and temperature of postpolymerization significantly influenced the DC of each resin: when time and/or temperature increased, the DC increased. For all resins tested, the lowest DC was obtained with a postcuring protocol at 10 min and 20 °C, and the highest DC was obtained at 90 min and 80 °C. However, at 80 °C, the samples showed a yellowish color. CONCLUSIONS: With the Form Cure device, the time and temperature of postcuring could have an impact on the DC of the 3D printing resins studied. The DC of the 3D printing resins could be optimized by adjusting the postpolymerization protocol. CLINICAL RELEVANCE: Regardless of the resin used, when using the Form Cure device, postcuring at 60 min and 60 °C would be the minimal time and temperature conditions for achieving proper polymerization. Beyond that, it would be preferable to increase the postcuring time to boost the DC.
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Resinas Compostas , Contenções , Resinas Compostas/química , Fatores de Tempo , Aparelhos Ortodônticos , Espectroscopia de Infravermelho com Transformada de Fourier , Impressão Tridimensional , Teste de Materiais , PolimerizaçãoRESUMO
PURPOSE: To mechanically characterize and assess the biological properties of Ti6Al4V surfaces obtained by Selective Laser Melting in order to determine whether this process is conceivable for production of implant-supported prostheses and particularly trans-gingival components. As-built and polished surfaces were studied in comparison with components obtained by computer numerical control machining technology in order to consider whether the properties are in the same range as the conventional method currently used. MATERIALS AND METHODS: Cylindrical specimens of Ti6Al4V (n = 6) were built with Selective Laser Melting for the characterization of mechanical properties according to ISO 22674 and discs (n = 12) were fabricated in the same conditions for cytotoxicity evaluation. Discs (n = 12) of Ti6Al4V were also obtained by computer numerical control machining as control. Half of the number of discs (n = 6) from each process were polished, to simulate the laboratory protocol for polishing of transmucosal components and half of the discs remained unaltered (as-built). Surface roughness measurements of disc specimens (as-built and polished) were compared with computer numerical control milling specimens (as-built and polished). Proliferation of human gingival fibroblasts on Ti6Al4V surfaces was also assessed for each condition. Viability and cell morphology were then evaluated qualitatively. Ra and Sa data were compared using Student's t-test (α = 0.05) and metabolic activity data were compared using Kruskal-Wallis statistical test (α = 0.05). RESULTS: Selective Laser Melting specimens showed elongation at break greater than 2% and 0.2% yield strength better than 500MPa which complied with ISO 22674 standards. Although Selective Laser Melting samples displayed significantly increased roughness on as-built surfaces compared to computer numerically controlled milling samples (p < 0.05), no statistically significant difference was observed after mechanical polishing (p = 0.279). Regarding metabolic activity, no statistical difference was observed between groups at day 3 (p > 0.05) and fibroblasts showed a viability higher than 97% on all discs. Cell shapes on polished samples suggested moderate adhesion compared to unpolished samples. CONCLUSION: With the manufacturing parameters selected in this study, Selective Laser Melting of Ti6Al4V appeared to be compatible with a prosthetic application type 4 according to ISO 22674. Surfaces obtained, followed by recommended postprocessing provided components with equivalent biological properties compared to computer numerical control machining technology.
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Implantes Dentários , Titânio , Ligas , Fibroblastos , Humanos , Lasers , Teste de Materiais , Propriedades de SuperfícieRESUMO
BACKGROUND: Children with first permanent molar affected by molar-incisor hypomineralization (MIH) show high treatment failure rate. AIM: To conduct a systematic review on bonding of adhesive materials to MIH-affected enamel, so as to identify all the methods suggested to optimize it and to determine the best bonding protocol(s). DESIGN: An exhaustive literature search was conducted on MEDLINE/PubMed, the Cochrane Library, and Web of Science databases, up to October 2018. Laboratory and clinical studies, involving adhesive restorations bonded to MIH-affected enamel, with at least a comparative group were included. Two authors independently selected studies, collected data, and assessed bias risk. RESULTS: After title and abstract review and duplicate exclusion, 14 articles were selected on the 496 eligible papers. After full reading, 4 articles were excluded. Finally, 10 studies (6 laboratory and 4 clinical studies) were included. CONCLUSIONS: Bond strength of composite was not significantly different when using self-etch compared with etch-and-rinse adhesives. Deproteinization after etching for etch-and-rinse adhesives enhanced bond strength; this could allow to keep MIH-affected enamel. Icon® showed an erratic penetration; however, a preliminary deproteinization after etching could improve bond strength. A study reported no significant differences in sealant retention rate, whereas another recommended to previously apply an adhesive.
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Colagem Dentária , Adesivos Dentinários , Condicionamento Ácido do Dente , Criança , Resinas Compostas , Cimentos Dentários , Esmalte Dentário , Humanos , Incisivo , Teste de Materiais , Dente Molar , Cimentos de Resina , Resistência ao CisalhamentoRESUMO
OBJECTIVE: This study investigated the shear bond strength (SBS) and interface between a resin composite and a new high-viscous glass ionomer cement (HV-GIC), a HV-GIC, a resin-modified glass ionomer cement (RM-GIC), a bulk-fill flowable composite, and a regular flowable composite bonded with various adhesive systems. METHODS AND MATERIALS: A resin composite (Filtek Z350) was bonded to a new HV-GIC (EQUIA Forte Fil) using various adhesive systems, including a universal adhesive in self-etch and etch-and-rinse mode (Scotchbond Universal), a two-step etch-and-rinse adhesive (Scotchbond 1-XT), a one-step self-etch adhesive (Optibond All-in-one) tested also after silane application (Monobond Plus), and a coating material (EQUIA Forte Coat). The resin composite was also bonded to a HV-GIC (Fuji IX GP), a RM-GIC (Fuji II LC), a bulk-fill flowable composite (SDR), and a regular flowable composite (Tetric Evo Flow) with the universal adhesive in self-etch mode (Scotchbond Universal). Two-way ANOVA followed by Dunnett's post hoc test was used to investigate the difference in SBS. Failures were analyzed by chi-square test. Bonding interfaces were examined by environmental scanning electron microscopy (E-SEM). RESULTS: SBS to EQUIA Forte Fil was significantly lower with Scotchbond 1-XT than with all other adhesive systems. By using Scotchbond Universal with the self-etch technique, the SBS to EQUIA Forte Fil was significantly higher than the SBS to Fuji IX GP and significantly lower than the SBS to Fuji II LC, SDR, and Tetric Evo Flow. E-SEM images showed an intimate contact at all interfaces examined. CONCLUSION: EQUIA Forte Fil showed satisfactory SBS and interfaces with all adhesives tested. CLINICAL RELEVANCE: Bonding between the resin composite and HV-GIC can be achieved using a universal adhesive in self-etch mode, an easy-to-use adhesive system.
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Resinas Compostas , Colagem Dentária , Cimentos Dentários , Resistência ao Cisalhamento , Cimentos de Ionômeros de Vidro , Teste de Materiais , Cimentos de ResinaRESUMO
The dental milling machine is an important device in the dental CAD/CAM chain. Nowadays, dental numerical controlled (NC) milling machines are available for dental surgeries (chairside solution). This article provides a mechanical engineering approach to NC milling machines to help dentists understand the involvement of technology in digital dentistry practice. First, some technical concepts and definitions associated with NC milling machines are described from a mechanical engineering viewpoint. The technical and economic criteria of four chairside dental NC milling machines that are available on the market are then described. The technical criteria are focused on the capacities of the embedded technologies of these milling machines to mill both prosthetic materials and types of shape restorations. The economic criteria are focused on investment costs and interoperability with third-party software. The clinical relevance of the technology is assessed in terms of the accuracy and integrity of the restoration.
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Desenho Assistido por Computador/instrumentação , Planejamento de Prótese Dentária , Sistemas Automatizados de Assistência Junto ao Leito , Cerâmica/química , Resinas Compostas/química , Desenho Assistido por Computador/economia , Custos e Análise de Custo , Materiais Dentários/química , Planejamento de Prótese Dentária/instrumentação , Eficiência , Engenharia , Desenho de Equipamento , Segurança de Equipamentos , Humanos , Reprodutibilidade dos Testes , Tecnologia Odontológica/instrumentação , Fluxo de TrabalhoRESUMO
Nowadays, dental numerical controlled (NC) milling machines are available for dental laboratories (labside solution) and dental production centers. This article provides a mechanical engineering approach to NC milling machines to help dental technicians understand the involvement of technology in digital dentistry practice. The technical and economic criteria are described for four labside and two production center dental NC milling machines available on the market. The technical criteria are focused on the capacities of the embedded technologies of milling machines to mill prosthetic materials and various restoration shapes. The economic criteria are focused on investment cost and interoperability with third-party software. The clinical relevance of the technology is discussed through the accuracy and integrity of the restoration. It can be asserted that dental production center milling machines offer a wider range of materials and types of restoration shapes than labside solutions, while labside solutions offer a wider range than chairside solutions. The accuracy and integrity of restorations may be improved as a function of the embedded technologies provided. However, the more complex the technical solutions available, the more skilled the user must be. Investment cost and interoperability with third-party software increase according to the quality of the embedded technologies implemented. Each private dental practice may decide which fabrication option to use depending on the scope of the practice.
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Desenho Assistido por Computador/instrumentação , Planejamento de Prótese Dentária/instrumentação , Laboratórios Odontológicos , Desenho Assistido por Computador/economia , Materiais Dentários/química , Planejamento de Prótese Dentária/economia , Planejamento de Prótese Dentária/normas , Eficiência , Engenharia , Desenho de Equipamento , Humanos , Investimentos em Saúde , Laboratórios Odontológicos/economia , Sistemas Automatizados de Assistência Junto ao Leito/economia , Propriedades de Superfície , Tecnologia Odontológica/instrumentaçãoRESUMO
As is the case in the field of medicine, as well as in most areas of daily life, digital technology is increasingly being introduced into dental practice. Computer-aided design/ computer-aided manufacturing (CAD/CAM) solutions are available not only for chairside practice but also for creating inlays, crowns, fixed partial dentures (FPDs), implant abutments, and other dental prostheses. CAD/CAM dental practice can be considered as the handling of devices and software processing for the almost automatic design and creation of dental restorations. However, dentists who want to use dental CAD/CAM systems often do not have enough information to understand the variations offered by such technology practice. Knowledge of the random and systematic errors in accuracy with CAD/CAM systems can help to achieve successful restorations with this technology, and help with the purchasing of a CAD/CAM system that meets the clinical needs of restoration. This article provides a mechanical engineering viewpoint of the accuracy of CAD/ CAM systems, to help dentists understand the impact of this technology on restoration accuracy.
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Desenho Assistido por Computador , Planejamento de Prótese Dentária , Prótese Dentária , Algoritmos , Simulação por Computador , Desenho Assistido por Computador/instrumentação , Desenho Assistido por Computador/normas , Desenho Assistido por Computador/estatística & dados numéricos , Prótese Dentária/normas , Prótese Dentária/estatística & dados numéricos , Planejamento de Prótese Dentária/normas , Planejamento de Prótese Dentária/estatística & dados numéricos , Engenharia/normas , Desenho de Equipamento , Humanos , Reprodutibilidade dos Testes , Propriedades de Superfície , Tecnologia Odontológica/normas , Interface Usuário-Computador , Fluxo de TrabalhoRESUMO
Treatment of patients with amelogenesis imperfecta extends over many years, from childhood to early adulthood. Their management at any age is complex and has to be adapted in relation to therapies validated in the general population.
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OBJECTIVE: To evaluate the shear bond strength (SBS) of a restorative resin-modified glass ionomer cement (RMGIC) for orthodontic bracket bonding. MATERIALS AND METHODS: One hundred twenty-one human teeth were randomly divided into 11 groups (n = 11) according to the surface treatment applied (H3PO4 ± Transbond Plus (TSEP) or Scotchbond Universal (SU)), and the adhesive used (Riva LC HV (RIVA), Fuji Ortho (FUJI), and Transbond XT (TXT)). For each sample, a metal button was bonded. SBS tests were performed at 1 week and debonded specimens were observed for failure modes determination. One-way ANOVA followed by Tukey's post hoc test was used to compare SBS differences and Fisher's exact test to analyze the failure modes (p < 0.05). RESULTS: TSEP + FUJI and H3PO4 + SU + TXT showed the highest SBS values while H3PO4 + TSEP + RIVA showed the lowest value. Cohesive failure and mixed failure were found in the groups with SU and TXT and adhesive failure in the other groups. DISCUSSION/CONCLUSIONS: The bonding of orthodontic attachments to enamel could be performed with any of the three materials studied. The use of a universal adhesive in the bonding protocol could optimize the adhesion values. Clinical studies would be needed to confirm the results obtained.
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OBJECTIVE: The aim of this study was to evaluate the remineralizing properties of ion-releasing restorative materials on pH cycling-induced carious dentin. METHODS: Fifty sound molars were freshly extracted. The occlusal surfaces were abraded using water-cooled sandpaper (800 grit). The residual crowns were embedded in self-cured acrylic resin with the flat dentin surface exposed. A mesio-distal trench was created using a calibrated 0.5 mm deep occlusal reduction burr, and artificial dentin caries were generated by pH cycling. Then, teeth were randomly assigned to five groups according to the ion-releasing material used. For each sample, micro-CT acquisitions were performed at various intervals. Remineralization was assessed by mean gray value (MGV) measurements after registration and segmentation of the region of interest with 3D Slicer software. One-way repeated-measures ANOVA followed by Tukey's post hoc test was used to investigate the difference in MGVs among the various groups. RESULTS: Only Cention Forte showed significantly increased MGVs after 4 weeks compared to demineralized dentin. MGVs were higher, but not significantly, after placement of the restorative materials, including in the resin composite control group. These results can be explained by the radiopacity of the materials. SIGNIFICANCE: Cention Forte, the material with the highest radiopacity, showed a significant increase in the MGVs of artificially carious dentin after 4 weeks. However, the study of dentin remineralization by micro-CT could be impacted by the radiopacity of the restorative materials used. The relevance of this examination for the study of dentinal remineralization should be investigated.
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Cárie Dentária , Cimentos de Ionômeros de Vidro , Humanos , Cimentos de Ionômeros de Vidro/química , Microtomografia por Raio-X , Materiais Dentários/química , Cárie Dentária/terapia , Resinas Compostas/química , Dentina/química , Teste de MateriaisRESUMO
PURPOSE: The aim of this study was to investigate the dentin shear bond strength (SBS) and bonding interface of three recently developed "universal" resin luting cements based on different modalities. METHODS: The dentin SBS and interfacial analysis of three recently launched "universal" resin luting cements, namely, G-Cem One, RelyX Universal and Panavia SA cement universal, were studied. All bonding protocols, including the previous use of their dedicated primer or universal adhesive in touch-cure mode or light-cure mode were performed. Variolink Esthetic LC used in conjunction with Scotchbond Universal Plus was used as a control group. For each group (n = 9), 10 specimens were tested for dentin SBS and two were examined by scanning electron microscopy. SBS were analyzed by two-way ANOVA followed by Dunnett's test. RESULTS: SBS values showed that the three "universal" resin luting cements tested exhibit different adhesive behaviors. G-Cem One with its touch-cure activated primer had a greater SBS to dentin (25.5 MPa) than that of the control group (22.1 MPa). CONCLUSION: "Universal" resin luting cements have variable efficacy when used in self-curing mode. The touch-curing mode is also of concern but may show high potential for some formulations.
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Dentina , Cimentos de Resina , Cimentos de Resina/química , Microscopia Eletrônica de Varredura , Humanos , Teste de Materiais , Resistência ao CisalhamentoRESUMO
The restoration of endodontically treated teeth (ETT) remains a significant challenge in modern dentistry. These teeth often suffer from substantial structural damage due to both the original pathology and the invasive nature of endodontic procedures. Consequently, ETT are more susceptible to fractures compared to vital teeth, necessitating restorative strategies that can effectively restore both function and aesthetics while minimizing the risk of failure. In recent years, advances in adhesive dentistry and the development of high-strength ceramics have further expanded the restorative options for ETT. Bonded restorations have gained popularity as they preserve more tooth structure and enhance the overall strenght of the tooth-restoration complex. The choice of restorative material and technique is influenced by numerous factors, including the amount of remaining tooth structure, the functional requirements of the tooth, and the aesthetic demands of the patient. Despite the plethora of available materials and techniques, the optimal approach to restoring ETT remains a topic of ongoing research and debate. In this comprehensive review, the current state of and recent advances in restoring damaged endodontically treated teeth are explored. Numerous therapeutic options exist, involving a wide range of materials. This article aims to present the biomaterial advancements of the past decade and their applications, offering alternative approaches to treating damaged ETT with the goal of prolonging their retention on the dental arch and serving as a valuable resource for dental practitioners who face this issue daily.
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PURPOSE/OBJECTIVES: Treating intraosseous lesions (IOLs) and interradicular bone lesions (IRLs) is an extremely technical dental procedure in periodontics. Instrumentation of these lesions is often perceived as difficult by students and inexperienced dentists before they perform a certain number of procedures on patients in the clinic. The aim of this article is to evaluate a cost-effective three-dimensional (3D)-printed educational simulator for the periodontal treatment of IOLs/IRLs (including scaling, incisions and sutures). METHODS: The simulators were first developed digitally, and then manufactured using printable resins and specific materials; finally, they were assembled using different bonding systems. To evaluate the simulators, assessments were gathered from two target populations: undergraduate students and periodontics experts. These individuals tested the simulator and completed a cross-sectional questionnaire based on a Likert scale with comparative and pedagogical items scored from one to five. The purpose of the questionnaire was to compare our simulator to clinical reality (i.e., operation on human jaws) and to an animal simulator (i.e., simulation of porcine jaws). The results are expressed as the mean and standard deviation and were statistically analyzed with the Wilcoxon signed-rank test. RESULTS: Overall, the results were satisfactory for both groups of testers (4.70 and 4.61 out of five for students and experts, respectively, for global satisfaction). CONCLUSIONS: The overall educational relevance of the simulator designed herein highlights the fact that 3D-printed educational simulators could enable efficient cognitive-functional learning for clinical IOL/IRL treatment.
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In this comprehensive review, the current state of the art and recent advances in 3D printing in dentistry are explored. This article provides an overview of the fundamental principles of 3D printing with a focus on vat photopolymerization (VP), the most commonly used technological principle in dental practice, which includes SLA, DLP, and LCD (or mSLA) technologies. The advantages, disadvantages, and shortcomings of these technologies are also discussed. This article delves into the key stages of the dental 3D printing process, from computer-aided design (CAD) to postprocessing, emphasizing the importance of postrinsing and postcuring to ensure the biocompatibility of custom-made medical devices. Legal considerations and regulatory obligations related to the production of custom medical devices through 3D printing are also addressed. This article serves as a valuable resource for dental practitioners, researchers, and health care professionals interested in applying this innovative technology in clinical practice.
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The objective of this study was to detail the monomer composition of resin-based dental materials sold in the market in 2023 and to evaluate the proportion of bisphenol A (BPA)-derivatives in relation to their applications. A search on manufacturers' websites was performed to reference resin-based dental materials currently on the European market (including the European Union (EU) and United Kingdom (UK). Their monomer composition was determined using material-safety data sheets and was completed by a search on the PubMed database. Among the 543 material compositions exploitable, 382 (70.3%) contained BPA derivatives. Among them, 56.2% contained BisGMA and 28% BisEMA, the most frequently reported. A total of 59 monomers, of which six were BPA derivatives, were found. In total, 309 materials (56.9%) contained UDMA and 292 (53.8%) TEGDMA. Less than one third of materials identified contained no BPA derivatives. These proportions vary a lot depending on their applications, with materials dedicated to the dental care of young populations containing the highest proportions of BPA-derivative monomers. The long-term effects on human health of the different monomers identified including BPA-derivative monomers is a source of concern. For children and pregnant or lactating women arises the question of whether to take a precautionary principle and avoid the use of resin-based dental materials likely to release BPA by opting for alternative materials.
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Introduction: Bonding to enamel is a daily problem for the orthodontist. While bonding to healthy enamel is nowadays well mastered, bonding to hypomineralized enamel is much less so. The aim of this article was to help the orthodontist to optimise bonding, whatever the clinical situation. Material and Method: Based on data from the literature, the clinical and microscopic characteristics of healthy and hypomineralised enamel, including amelogenesis imperfecta (AI), molar incisor hypomineralization (MIH), fluorosis or erosion will be described. Proposals for optimising bonding will then be identified and summarized. Results: Bonding to enamel is reliable, but the use of an etch-and-rinse mode (even with a universal adhesive) is recommended. For AI, MIH and fluorosis, the use of sodium hypochlorite after etching seems to significantly increase bonding. No treatment is needed for eroded enamel. However, deep resin infiltration for severe MIH or superficial resin infiltration for fluorosis would reduce the risk of enamel fracture during bracket removal. Conclusion: It is important to be aware of the characteristics of the dental substrate and the materials used to optimize procedures.
Introduction: L'adhésion à l'émail est une problématique quotidienne de l'orthodontiste. Si le collage à l'émail sain est aujourd'hui maîtrisé, celui sur l'émail hypominéralisé l'est beaucoup moins. L'objectif de cet article était d'aider l'orthodontiste à optimiser son collage, quelle que soit la situation clinique. Matériel et méthode: À partir des données issues de la littérature, les caractéristiques clinique et microscopique de l'émail sain et de l'émail hypominéralisé en cas d'amélogenèse imparfaite (AI), d'hypominéralisation de molaire incisive (MIH), de fluorose ou d'érosion seront décrites. Puis, les propositions d'optimisation du collage seront recensées et synthétisées. Résultats: Le collage à l'émail est fiable, mais l'utilisation d'un mode mordançage-rinçage (même avec un adhésif universel) est conseillée. Pour l'AI, la MIH et la fluorose, l'utilisation d'hypochlorite de sodium après mordançage semble significativement augmenter l'adhérence. Aucun traitement n'est nécessaire pour l'émail érodé. Cela dit, une infiltration de résine en profondeur pour les MIH sévères ou superficielles pour la fluorose permettrait de réduire le risque de fracture d'émail à la dépose de l'attache. Conclusion: Il convient de connaître les caractéristiques du substrat sur lequel on colle et celles des matériaux utilisés pour optimiser ses procédures.
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Amelogênese Imperfeita , Intoxicação por Flúor , Fluorose Dentária , Hipomineralização Molar , Humanos , Assistência Odontológica , Ortodontistas , Esmalte Dentário , Amelogênese Imperfeita/terapiaRESUMO
The cantilevered fixed partial denture (CFPD) is gaining recognition as a sound method of replacing missing teeth in the posterior sector. The purpose of this case report is to demonstrate that this type of restoration can be performed in a single appointment. A 39-year-old patient presented herself to the dental department; she showed agenesis of the two first maxillary premolars with a totally closed mesio-distal gap and a recent loss of the 2 s maxillary premolars. This case report concerns the replacement of the upper left second premolar. The patient was treated with a mesial CFPD resting on an "onlay-like" retainer on the first molar and replacing the missing premolar with a cantilevered pontic. The dimensions of the connection's cross-section were maximized as much as possible (>20 mm2). The restoration was designed and produced using chairside CAD-CAM from a milled-reinforced glass-ceramic block (Emax CAD, Ivoclar Vivadent). The aesthetic and functional integration of the prosthesis was successful. The patient was examined at 11 months for a follow-up. At this early stage, satisfactory dental hygiene was observed, associated with a smooth prosthetic fit, no periodontal inflammation, normal probing, and no abnormal dental mobility.
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The aim of this systematic review was to determine the optimal printing parameters for the producing of fused deposition modeling (FDM) 3D-printed polyetheretherketone (PEEK) elements with mechanical properties suitable for dental restorations. Indeed, the mechanical properties are a critical prerequisite for the study of other parameters, such as physical, aesthetic and biological properties. An exhaustive electronic search was carried out in the PubMed, Embase and Web of knowledge databases to gather all the studies evaluating the influence of the printing parameters on the obtained mechanical properties of FDM 3D-printed PEEK elements were selected. Initially, the search resulted in 614 eligible papers. Independent screenings of the abstracts were performed by two authors to identify the articles related to the question. Twenty-nine studies were selected, of which eleven were further excluded after reading of the full text, and finally, eighteen articles were included in this review. The studies were difficult to compare due to the variability of the printing parameters and the types of PEEK. However, it seems interesting to use a high infill rate, a high chamber temperature close to that of the printing temperature and a heat post-treatment to obtain 3D PEEK elements presenting properties adapted to use as dental restorations. The analysis of the available literature suggested that the properties of PEEK could make it an interesting material in dental restorations to be performed with FDM additive manufacturing.
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Introduction: The number of adult patients who seek an orthodontic treatment is increasing. These patients often have lithium disilicate ceramic restorations. The orthodontist has to find a procedure to bond effectively brackets to these restorations. In 2011, a new family of adhesives was introduced, universal adhesives, which are capable of bonding to ceramic and are said "multi-mode" because they can be used in etching-rinse or self-etching protocol on tooth surface. The objective of this in vitro study was to evaluate the shear bond strength (SBS) of metal brackets to lithium disilicate ceramic support using a universal adhesive. Materials and Methods: Forty machinable lithium disilicate blocks (IPS e.max CAD, Ivoclar) were prepared according manufacturer's instructions. Each specimen was randomly assigned to one of four groups (n=9 or 10) defined by the pretreatment protocol. Protocol 1: Hydrofluoric Acid 9 % (HF) + Silane + Orthodontic adhesive (Transbond™ XT Light Cure Adhesive Primer, 3M ESPE), protocol 2: HF + Universal adhesive (UA) (Scotchbond Universal®, 3M ESPE), protocol 3: UA only, protocol 4 : Monobond Etch & Prime® (Ivoclar) + UA. Then, a bracket of upper cuspid (3M ESPE) was bonded to each specimen with a composite resin (Transbond™ XT, 3M ESPE). SBS was measured between ceramic and bracket with a universal testing machine. A one-way ANOVA (ANalysis Of Variance) followed by Tukey's post-hoc test was performed to investigate SBS differences between groups. Results: Protocol 2 (43 MPa) and protocol 4 (36 MPa) showed the highest SBS values and were statistically different from protocol 1 (25 MPa) and protocol 3 (21 MPa). Conclusion: Despite the lower bond values obtained in the study, but higher than the minimum expected, the application of UA alone appears to be a safe procedure that seems to provide sufficiently strong and resistant bonding between the ceramic and the bracket. However, clinical studies are needed before a recommendation can be made.
Introduction: Les traitements orthodontiques chez l'adulte se démocratisent. Ces patients ont souvent des restaurations en céramique en disilicate de lithium, sur lesquelles l'orthodontiste doit être à même de coller efficacement ses attaches. Or, les adhésifs universels, nouvelle famille d'adhésifs introduite en 2011, présentent un potentiel d'adhésion aux céramiques, en plus de pouvoir être utilisés en mode mordançage-rinçage ou auto-mordançant. L'objectif de cette étude in vitro était d'évaluer l'adhérence d'attaches métalliques à ces céramiques à l'aide d'un adhésif universel. Matériels et méthodes: Quarante blocs de céramique en disilicate de lithium (IPS e.max CAD, Ivoclar) ont été préparés selon les recommandations de cristallisation du fabricant. Chaque échantillon a été ensuite réparti aléatoirement en quatre groupes (n = 9 ou 10) selon le protocole de traitement de surface appliqué. Protocole 1 : Acide Fluorhydrique 9 % (HF) + Silane + Adhésif orthodontique (Transbond™ XT Light Cure Adhesive Primer, 3M ESPE), protocole 2 : HF + Adhésif universel (AU) (Scotchbond Universal®, 3M ESPE), protocole 3 : AU uniquement, protocole 4 : Monobond Etch & Prime® (Ivoclar) + AU. Une attache métallique de canine maxillaire (3M ESPE) a ensuite été collée sur chaque échantillon avec une résine composite (Transbond™ XT, 3M ESPE). La résistance en cisaillement a ensuite été mesurée entre la céramique et l'attache métallique. Une ANOVA (ANalysis Of Variance ou analyse de variance) suivie du test post-hoc de Tukey ont été réalisés pour étudier les différences d'adhérence entre les groupes. Résultats: Les protocoles 2 (43 MPa) et 4 (36 MPa) présentent des valeurs d'adhérence significativement supérieures à celles des protocoles 1 (25MPa) et 3 (21 MPa). Conclusion: Malgré de plus faibles valeurs d'adhérence obtenues dans l'étude, mais supérieures à celles minimales attendues, l'application seule de l'adhésif universel semble être une procédure sans danger qui procure une adhésion suffisamment forte et résistante entre la céramique et l'attache. Des études cliniques sont cependant nécessaires avant d'émettre une recommandation.