Complete Denture Manufacturing Research Articles

Biomechanical Behavior of a 3D-Printed Denture Base Material.

To evaluate relevant material properties (flexural strength [σf], elastic modulus [E], water sorption [Wsp] and solubility [Wsl], and biocompatibility) of an additive manufacturing (AM) polymer vs a heat-curing acrylic resin (AR; control) for the manufacture of complete dentures, testing the hypothesis that fabrications from both materials would present acceptable material properties for clinical use. The σf, E, Wsp, and Wsl were evaluated according to the ISO 20795-1:2013 standard, and the biocompatibility was evaluated using MTT and SRB assays. Disk-shaped specimens were fabricated and used for Wsp (n = 5), Wsl (n = 5), and biocompatibility (n = 3) testing. For assessment of σf and E, bar-shaped specimens (n = 30) were fabricated and stored in 37°C distilled water for 48 hours or 6 months before flexural testing in a universal testing machine with a constant displacement rate (5 ± 1 mm/minute). Data from σf, E, Wsp, Wsl, and biocompatibility tests were statistically analyzed using Student t test (α = .05). Weibull analysis was also used for σf and E data. Significant differences between the two materials were found for the evaluated material properties. Water storage for 6 months did not affect the flexural strength of the AM polymer, but this material showed inadequate σf and Wsl values. Despite adequate biocompatibility and strength stability after 6 months of water storage, the AM polymer recommended for complete dentures needs further development to improve the material properties evaluated in this study.

Effect of digital complete dentures manufactured using the custom disk method on masticatory function

Statement of problemThe effect of using the custom disk method (CDM) for fabricating digital dentures on patients’ masticatory function should be studied to support its use in clinical practice. PurposeTo investigate the effect of digital dentures fabricated using CDM on patients’ masticatory function. Material and methodsThis single-center prospective clinical study included 20 patients with edentulous maxillary and mandibular arches who used a complete denture. The digital impression and complete denture manufacturing procedures using CDM have already been reported by Kanazawa et al. (2018) [32] and Soeda et al. (2022) [18] Thedigital dentures fabricated with CDM were delivered to the participants, and periodic adjustments were made until the patient could use the denture without pain. A color-changeable chewing gum, two types of gummy jellies that can evaluate the masticatory function, and pressure-sensitive sheets were used to evaluate the participants’ masticatory function at baseline, 1 month, and 6 months following adjustment of the new digital complete dentures fabricated with CDM. These masticatory function values had already been measured in the previous conventional dentures and were recorded as baseline values. ResultsThe study participants included 8 women and 12 men (mean age, 77.6 years). The color-changeable chewing gum analysis indicated that there was no significant improvement of masticatory function from baseline to 1 M (P = .083) and 6 M (P = .157).The gummy jelly analysis indicated no significant differences between the masticatory function baseline and 1 month (P = .387); however, a significant improvement was observed from baseline to 6 months (P = .020). Tests with Glucolum indicated a significant improvement from baseline to 1 month (P = .012) and 6 months (P = .003). The maximum bite force and occlusal contact area showed no significant difference at any time point. ConclusionsSignificant improvement in masticatory function was observed upon evaluation with gummy jelly and Glucolum 6 months after delivering the new digital complete dentures. Under limited conditions, the digital denture fabricated using CDM resulted in good recovery of the masticatory function in elderly edentulous patients. The present results combined with the cost-effectiveness and patient satisfaction associated with CDM indicate its clinical utility.

Fabrication of Metal-Reinforced Complete Dentures Using the CAD-CAM Technique

The digital manufacture of complete dentures would greatly simplify the workflow; however, the metal-reinforced complete dentures production method has not been well established. This article describes a technique of fabricating metal-reinforced complete dentures in a milling machine using the geometry guide, a negative impression of the occlusal surface of the metal-reinforced complete denture designed using the computer-aided design software. The geometry guide supports and stabilizes the artificial teeth and metal framework in the correct position in the surrounding resin. Fabrication of metal-reinforced dental prosthesis using the digital technique is possible with this method.

Bonding Behavior of Conventional PMMA towards Industrial CAD/CAM PMMA and Artificial Resin Teeth for Complete Denture Manufacturing in a Digital Workflow.

When applying a digital workflow, custom artificial resin teeth have to be integrated into a milled complete denture base, using polymethylmethacrylate (PMMA) applied with a powder–liquid technique. Debonding of denture teeth from dentures is reported to be a frequent complication. No evidence is provided as to which method of surface treatment may enhance the bonding strength. The bonding strength between artificial teeth and PMMA (Group A, n = 60), as well as between the PMMA and industrial PMMA (Group B, n = 60), was investigated following no treatment, monomer application, sandblasting, oxygen plasma, and nitrogen plasma treatment. Surface-roughness values and SEM images were obtained for each group. Shear bond strength (SBS) and fracture mode were analyzed after thermocycling. Within Group A, statistically significant higher SBS was found for all surface treatments, except for nitrogen plasma. In Group B, only nitrogen plasma showed a statistically lower SBS compared to the reference group which was equivalent to all surface treatments. Conclusions: Within the limitations of the present study, the monomer application can be proposed as the most effective surface-treatment method to bond custom artificial teeth into a milled PMMA denture base, whereas nitrogen plasma impairs the bonding strength.

Properties of Acrylic Resin For CAD/CAM: A Systematic Review and Meta-Analysis of In Vitro Studies.

This systematic review and meta-analysis of in vitro studies compared the prepolymerized acrylic resin used for CAD/CAM complete denture manufacturing versus the heat-polymerized acrylic resin for conventional complete dentures in terms of surface roughness, wettability, hardness and flexural strength. An electronic search was performed in the PubMed, Embase, LILACS and Web of Science databases, without language or date restrictions. Gray literature and manual search tools were also used. The systematic review was carried out by two researchers independently, following the inclusion criteria: in vitro studies testing the CAD/CAM acrylic resin with a control group of heat-polymerized acrylic resin which compared at least one of the four material properties above. The meta-analysis was performed separately for each property, using a random effect model. Of the 914 studies found by means of search strategies, 698 were selected for the systematic review. After applying the eligibility criteria, only 17 articles were selected for the qualitative analysis in the systematic review; among these, 14 were included in the quantitative meta-analysis. The CAD/CAM prepolymerized acrylic resin in blocks had similar properties when compared to heat-polymerized acrylic resin in almost all outcome measures, with the exception of a statistically significant reduction in surface roughness. Based on the findings of this systematic review and meta-analysis, equally satisfactory results can be expected from dental prosthesis manufactured by the CAD/CAM system when compared to conventional ones, with the additional potential of reducing the pigmentation and attached microorganisms due to the reduced surface roughness of the prepolymerized resin.

Precisão da adaptação de próteses totais confeccionadas pela tecnologia CAD/CAM: Uma revisão sistemática

Objetivo: Avaliar a precisão da adaptação de próteses totais confeccionadas pela tecnologia utilizando o desenho e a manufatura assistidas por computador (CAD/CAM).Metodologia: Foi realizada uma revisão sistemática de estudos laboratoriais através das bases de dados Medline-PubMed, Scopus, Scielo, Lilacs, Web of Science e Cochrane Library, usando os descritores: “Complete denture”, “Complete dentures”, “Total denture”, “Total dentures”, “Complete prosthesis”, “Complete prostheses”, “Total prosthesis”, “Total prostheses”, “Computer Aied Design”, “Computer Aied Manufacturing”, “CAD/CAM”, Adaptation” e “Precision”. Três revisores calibrados obtiveram dados e compararam os resultados. Todos os estudos avaliaram a precisão da adaptação de próteses totais confeccionadas pela tecnologia CAD/CAM. Esta revisão seguiu as recomendações do Preferred Reporting Items for Systematic Reviews and Meta-analyzes (PRISMA). Resultados: A estratégia utilizada de busca eletrônica e manual resultou em 863 títulos e resumos. Destes, 10 foram selecionados pelos critérios de inclusão e exclusão e lidos na íntegra. Ao final, 7 foram eleitos para inclusão na revisão. Os estudos selecionados demonstraram resultados satisfatórios em relação a adaptação e efetividade sobre as próteses confeccionadas a partir do processo CAD/CAM quando comparadas aos métodos convencionais. Conclusão: Os estudos in vitro demonstraram que o processo de fabricação de prótese total por meio do sistema CAD/CAM apresenta melhor precisão de adaptação quando comparados ao método convencional. O método de fresagem apresentou resultados superiores quando comparado ao por impressão 3D.

Using shape memory effect to obtain a new polymer for the manufacture of complete dentures

Currently, polymeric materials represent a very important place in all areas of human activity, taking part more and more in life, day by day. Of these, synthetic polymeric biomaterials - simple or composite - constitute a very trendy topic and with a great dynamic, given to the diversity of their use in medical and pharmaceutical fields. In this respect the study aims improving the quality of acrylates used for removable dentures, by incorporating vitamin B12 into the structure of acrylic polymer for the treatment of the oral aphthae, as well as for prophylactic purpose. Structural characteristics of researched polymer indicates that a large number of factors that contribute to complex sites with affinity for the template does exist.

Statistical analysis of repair of complete removable dentures on the upper jaw for a three-year period of use.

The aim of the study is a analyze the use of full dentures on the upper jaw and the number of repeated visits of patients who received treatment at the dental offices in the Dnepr city. Materials and methods: during 2015–2017 years in dental office of the SE “DMA”, patients were examined, a statistical analysis was made, the number of manufactured of full dentures on the upper jaw and, accordingly, the number of repairs for each year and comparison statistics with the city dental clinics in the previous years was done. According to the results of the study, it was established then in three-year examination period the patients in three dental clinics of the city, the percentage of breakdowns and correction of full dentures on the upper jaw was near 50%. At dental office of SE “DMA”, according to the results 2015-2017 years a numbers of 48.4% was obtained .So that when we compared with the dental clinic from the previous study that is closest in scope of the work, it indicates the absence of statistically significant differences in the indicators of the first and second studies. This can be explained by the fact that despite the use of more modern materials and methods in the manufacture of complete dentures, the problem of improving the quality of full dentures manufacturing on the upper jaw and increasing the strength of the base has not been fully resolved.

Nanocomposite for Rapid Prototyped Complete Denture Eighteen months follow-up on clinical performance

The aim of the present study was to evidence the improved behavior of our modified PMMA-TiO2 nanocomposite material used to obtain 3D printed complete dentures. A protocol for long-term rapid prototyping complete denture manufacturing using our nanocomposite material, completely characterized and the evaluation of the clinical performance and complications after eighteen months of continuous wearing was also described. Thirty-five fully edentulous patients were enrolled in this prospective clinical study and forty-five complete dentures (31 maxillary and 14 mandibular) have been obtained using an additive manufacturing technology. Due to the good performances of the nanocomposite material, no major functional complications for the obtained medical devices occurred and the clinical outcomes for the 3D printed dentures were favorable evaluated at eighteen months follow up.

Structural Investigations on Poly(methyl methacrylate) Various Composites Used for Stereolithographyc Complete Dentures

The present paper is focused on analyzing if appropriate adhesion between the polymeric matrix and titania filler nanoparticles is obtained for the PMMA-TiO2 photo-curable dental material, suitable for application in RP - stereolithography (SLA) for complete denture manufacturing. It was found that different amounts, between 0.2% and 2.5 % (w/w%), of added titanium oxide nanoparticles slightly modify the structural behavior of the PMMA polymeric matrix. The material characterization was carried out using FT-IR and microscopy techniques.

Preliminary Studies on Citotoxicity and Genotoxicity Assessment of the PMMA-TiO2 Nanocompozites for Stereolithographic Complete Dentures Manufacturing

The aim of the present study was to characterize and preliminary assess the cytotoxicity and genotoxicity of different PMMA-TiO2 nanocomposites suitable to be used for two-parts stereolithographic complete denture manufacturing. In order to improve mechanical and antibacterial characteristics of the materials for 3D printing dentures, two matrix materials consisting in commercially available solutions of poly(methyl methacrylate) (PMMA), referred as dent-PMMA respectively base-PMMA, have been doped with different amount of TiO2 nanoparticles: 0.4, 0.6, 1.0, and 4.0% by weight. The obtained nanocomposites were structural characterized and assessed for antibacterial activity, cytotoxicity and genotoxicity. The newly obtained nanocomposites presented a good inhibitory action against the considered bacterial species-Staphylococcus aureus, good biocompatibility under 4.0% by weight. The results of the preliminary studies on cytotoxicity and genotoxicity assessment recommends the use of 0.4% TiO2 dent-PMMA and base-PMMA for CAD/CAM additive manufacturing of two-parts complete dentures/overdentures.

Carboxylic acid-functionalized TiO2 nanoparticle-loaded PMMA/PEEK copolymer matrix as a dental resin for 3D complete denture manufacturing by stereolitographic technique

ABSTRACTThe main goal of the present investigation was to the synthesis of bioactive TiO2 nanoparticle-incorporated poly(methylmethacrylate)/polyetheretherketone nanocomposite for enhanced antibacterial and biocompatibility characteristics with suitable properties for manufacturing 3D printed stereolitographic dental prosthesis. The carboxylic acid-functionalized TiO2 nanoparticles have been dispersed into the copolymer matrixes through emulsion polymerization method, and the structural and morphological properties were investigated by using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy, and energy dispersive X-ray (EDX) analytical techniques. The FTIR spectrum of synthesized nanocomposites that shows high intense peaks at 2,970–2,850 cm−1 is related to the symmetric and asymmetric stretching C-H vibration of methyl and methylene groups of the polymer matrix. The microscopic results of nanocomposite exhibited that functionalized nanoparticles were effectively and uniformly dispersed into the polymer matrix in the absence of particle agglomerations, and it has been given excellent killing efficiency of 99% under dark conditions against bacterial pathogens Escherichia coli and Staphylococcus aureus and also exhibited favorable cell compatibility with dental pulp cells. This facile synthesized nanocomposite was efficaciously employed for denture manufacturing with stereolitographic technique.

Poly(methyl methacrylate) with TiO2 nanoparticles inclusion for stereolitographic complete denture manufacturing − the fututre in dental care for elderly edentulous patients?

ObjectivesThe aim of this study was to obtain a Poly(methylmethacrylate) (PMMA)-TiO2 nanocomposite material with improved antibacterial characteristics, suitable for manufacturing 3D printed dental prosthesis. Methods0.2, 0.4, 0.6, 1, 2.5 by weight% of TiO2 nanoparticles have been added to the commercially available stereolithographic PMMA material and the obtained nanocomposites have been analyzed using FTIR, SEM and also tested for antimicrobial efficacy against bacterial cultures from Candida species (C. scotti). ResultsSEM images and EDX results highlighted the presence of TiO2 in PMMA nanocomposites. The elemental composition (EDX) also showed the presence of other fillers included in stereolithographic PMMA solution. FTIR analysis clearly revealed changes in polymeric matrix structure when adding TiO2 nanoparticles.Sample containing 0.4, 1 and 2.5wt% TiO2 nanoparticles inhibited the growth of Candida scotti strain in standard conditions according to the toxicity control method (DHA).Increasing quantity of nano-titania has resulted in particles fooling, forming new aggregates instead of the homogenous dispersion of nanoparticles with modified viscosity characteristics and expected lower mechanical parameters. ConclusionsSignificant improvements in polymer characteristics and nice dispersion of the TiO2 nanoparticles have been noticed for 0.4wt%, therefore it was used for stereolitographic complete denture prototyping. Clinical significanceIncorporation of TiO2 nanoparticles in PMMA polymer matrix was proved to have antibacterial effects, specifically on Candida species. The newly obtained 0.4% nanocomposite was successfully used with stereolitographic technique for complete denture manufacturing. However, mechanical and biocompatibility tests need to be performed in order to extend the clinical usage.

Custom fabrication of try-in wax complete denture

Purpose The use of removable complete dentures is a selectable restorative procedure for edentulous patients. To improve the fabrication quality and efficiency of removable complete dentures, this paper aims to introduce a new method to fabricate customized wax complete dentures with additive manufacturing. This process uses complementary digital technologies, and allows faster and better manufacture of complete dentures. Design/methodology/approach In the study, a dental scanner was used to obtain surface data from edentulous casts and rims made by the dentist. A parameterized three-dimensional graphic database of artificial teeth was pre-established. Specialized computer-aided design software was used to set up the artificial dentition and design the esthetic gingiva and base plate. A selective laser sintering machine was used to transfer the data from stereolithography files into a wax base plate with location holes for each artificial tooth. Findings Under this method, a set of wax base plates with 28 location holes available for the placement of the artificial teeth were designed and fabricated within 6 h. The try-in wax dentures fitted the patient’s mouth well, besides occlusion relationships. Then, the occlusion relationships can be adjusted manually to achieve a balanced centric occlusion. Originality/value This method can be used to design and fabricate wax try-in removable complete dentures semi-automatically and rapidly; however, the algorithm for the occlusion contact design needs to be improved.

Collaborative Simulation and Experimentation on the Dental Arch Generator of a Multi-manipulator Tooth-arrangement Robot

In the orthodontic treatment and manufacture of complete dentures, the most important steps are designing and generating a dental arch curve which adapts to the requirements of the patient according to their jaw arch form. The traditional way of acquiring the dental arch curve form is based on manual operation, which will randomly generate a lot of errors caused by human factors. The purpose of this paper is to automatically acquire the dental arch curve and implement the coordinated control of the dental arch generator of the multi-manipulator tooth-arrangement robot, which can be used in full denture manufacturing. According to the work principle, motion planning method of the dental arch generator will be analysed. A collaborative simulation of the dental arch generator is realized based on Matlab and ADAMS. Controlled experimentation of the dental arch generator and preliminary tooth-arrangement experimentation are performed using the multi-manipulator tooth-arrangement robot system in order to verify the feasibility of the motion planning method and the technical route. It will lay an important theoretical foundation for quantitative research on oral restoration and also provide a way to standardize the manufacturing process of full dentures and orthodontic treatments.

Study on the multi‐manipulator tooth‐arrangement robot for complete denture manufacturing

PurposeIt is not an easy and simple task to manufacture a complete denture with high quality. Traditionally, it often needs a medical expert with experience and hand‐on skill, due to the manual way of denture manufacturing. The purpose of this paper is to implement the multi‐manipulator tooth‐arrangement robot system that can fully automate the denture manufacturing process.Design/methodology/approachA novel complete denture manufacturing mechanism is designed, which is based on the multi‐manipulator and dental arch generator. The visual tooth‐arrangement and robot control software is developed in VC++6.0. Preliminary experiments on tooth‐arrangement have been conducted using the proposed multi‐manipulator tooth‐arrangement robot prototype system.FindingsThe multi‐manipulator tooth‐arrangement robot prototype system can automatically design and manufacture a set of complete denture that fit a patient by visual tooth‐arrangement and robot control software according to the patient's jaw arch parameters.Research limitations/implicationsThe implication of research is that it is feasible that the manufacture strategy of complete denture fulfilled by multi‐manipulator tooth‐arrangement robot. The limitation of research is that it is difficult to realize coordinate control.Originality/valueThe traditional manual method which makes complete denture by medical personal experience will be changed after the multi‐manipulator tooth‐arrangement robot system is manufactured, and adjustment to each tooth position and orientation will be realized by this system.

Kinematics Modeling and Experimentation of the Multi-manipulator Tooth-Arrangement Robot for Full Denture Manufacturing

Artificial teeth are very complicated in shape, and not easy to be grasped and manipulated accurately by a single robot. The method of tooth-arrangement by multi-manipulator for complete denture manufacturing proposed in this paper. A novel complete denture manufacturing mechanism is designed based on multi-manipulator and dental arch generator. Kinematics model of the multi-manipulator tooth-arrangement robot is built by analytical method based on tooth-arrangement principle for full denture. Preliminary experiments on tooth-arrangement are performed using the multi-manipulator tooth-arrangement robot prototype system. The multi-manipulator tooth-arrangement robot prototype system can automatically design and manufacture a set of complete denture that is suitable for a patient according to the jaw arch parameters. The experimental results verified the validity of kinematics model of the multi-manipulator tooth-arrangement robot and the feasibility of the manufacture strategy of complete denture fulfilled by multi-manipulator tooth-arrangement robot.

Robotic system approach for complete denture manufacturing

A robotic system for complete denture manufacturing, which can realize automatic implanting of artificial teeth, is described. The tooth arrangement algorithm is presented, including the equations of jaw-arch curve and teeth-arch curve, setup of a single tooth coordinate system and calculation of tooth position in teeth-arch curve. An expert system software is developed that integrates high-level dentist experiences and dexterous technician skills. Three-dimensional (3-D) display of tooth arrangement, human-computer interactive adjustment of tooth position and orientation in teeth-arch curve are achieved. Robot path planning and control data creation are realized by this software also. Finally, an experiment of complete denture manufacturing is made for a patient, a pair of complete dentures is obtained, and the results are analyzed. This robotic system is expected to change the manner of complete denture manufacturing wholly, and significantly improve product quality and manufacturing efficiency.

Tooth arrangement for the manufacture of a complete denture using a robot

The successful application of robots in surgery and other medical fields prompts us that robots can also play an important role in oral restoration. The traditional way of complete denture manufacturing is manual and only high‐level dentists and skilled technicians can do this work well. But we believe that a robot can do this work better and more easily. Artificial teeth are very complicated in shape, and not easy to be grasped and manipulated accurately by a robot gripper. Aiming at improving our previous robot manufacturing system of complete dentures, we present a new method to perform teeth implanting. We improve the previous manufacturing procedure by adding several components in the operating process. By this method, the robot gripper only needs to grasp and implant intermediate blocks, which have very simple shapes and are easy to handle precisely. The 3D human‐machine tooth arrangement software performs the calculation of intermediate blocks’ positions and orientations. We perform the experiment of tooth arrangement for a patient, and obtain a pair of ideal tooth arches. A complete denture can be manufactured according to this result.