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1.
J Long Term Eff Med Implants ; 34(4): 33-47, 2024.
Article in English | MEDLINE | ID: mdl-38842231

ABSTRACT

This virtual study was designed to evaluate the stress-deformation of a metal fixed partial dentures (FPDs) pontic under different loads using two different connectors. The STL file was generated for a RPD of two implant-supported restorations. The Co-Cr metal substructure was designed with two types of connector design. The pontic is connected to implant-supported crowns with square and round shape connectors. This study was designed for a cementless-retained implant-supported FPD. Finite element modeling (FEM) is used to assess the stress and deformation of the pontic within a metal substructure as the FEM might provide virtual values that could have laboratory and clinical relevance. The Co-Cr alloy mechanical properties like the Poisson ratio and modulus of elasticity were based on the parameters of the three-dimensional structure additive method. Nonparametric analyses (Mann-Whitney U test) was used. The use of square or round connectors often resulted in non-significant changes in stress, and deformation under either three or each loaded point on the occlusal surface of a pontic (P > 0.05). However, the deformation revealed distinct variations between loads of the three points compared to each loaded point (P ≤ 0.05). According to this study data, the pontic occlusal surface appears to be the same in stress and deformation under different loads depending on whether square or round connectors are used. While at the same connector designs, the pontic occlusal surface deformed significantly at three loaded points than it did at each point.


Subject(s)
Dental Prosthesis, Implant-Supported , Denture, Partial, Fixed , Finite Element Analysis , Humans , Chromium Alloys/chemistry , Denture Design , Dental Stress Analysis , Stress, Mechanical
2.
BMC Oral Health ; 24(1): 671, 2024 Jun 08.
Article in English | MEDLINE | ID: mdl-38851680

ABSTRACT

The latest generation of intraoral scanners can record the prosthetic field with relative ease, high accuracy and comfort for the patient, and have enabled fully digital protocols for designing and manufacturing complete dentures. The present study aims to examine the intaglio surface trueness of 3D printed maxillary dentures produced by fully digital workflow in comparison with dentures produced by analogue clinical and laboratory prosthetic workflow. The edentulous maxillary arch of 15 patients was scanned with an intraoral scanner as well as the intaglio of the delivered conventional denture. The scan of the edentulous arch was imported into a dental design software to produce the denture base which was then 3D printed. The intaglio surface of the finished 3D printed denture bases was digitized and used to assess the trueness of the printed denture bases compared to the intaglio surface of the conventional dentures as well as performing a trueness comparison in relation to the scanned edentulous arches. The dataset (n = 30) was subjected to Kruskal-Wallis test analysis, the significance level being established at α = 0.05. The results of the study showed that the printed group displayed better trueness values with a median of 176.9 µm while the analogue group showed a median of 342 µm. Employing a fully digital workflow to produce 3D-printed denture bases yields a consistent and precise manufacturing method when accounting for the intaglio surface of the denture.


Subject(s)
Denture Bases , Denture Design , Printing, Three-Dimensional , Workflow , Humans , Denture Design/methods , Computer-Aided Design , Female , Jaw, Edentulous , Denture, Complete, Upper
3.
Clin Exp Dent Res ; 10(3): e880, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38798134

ABSTRACT

OBJECTIVE: To study the feasibility of using poly methyl methacrylate (PMMA) filament and fused deposition modeling (FDM) to manufacture denture bases via the development of a study that considers both conventional and additive-based manufacturing techniques. MATERIALS AND METHODS: Five sample groups were compared: heat and cold cured acrylic resins, CAD/CAM milled PMMA, 3D-printed PMMA (via FDM), and 3D-printed methacrylate resin (via stereolithography, SLA). All groups were subjected to mechanical testing (flexural strength, impact strength, and hardness), water sorption and solubility tests, a tooth bonding test, microbiological assessment, and accuracy of fit measurements. The performance of sample groups was referred to ISO 20795-1 and ISO/TS 19736. The data was analyzed using one-way ANOVA. RESULTS: Samples manufactured using FDM performed within ISO specifications for mechanical testing, water sorption, and solubility tests. However, the FDM group failed to achieve the ISO requirements for the tooth bonding test. FDM samples presented a rough surface finish which could ultimately encourage an undesirable high level of microbial adhesion. For accuracy of fit, FDM samples showed a lower degree of accuracy than existing materials. CONCLUSIONS: Although FDM samples were a cost-effective option and were able to be quickly manufactured in a reproducible manner, the results demonstrated that current recommended testing regimes for conventionally manufactured denture-based polymers are not directly applicable to additive-manufactured denture base polymers. Therefore, new standards should be developed to ensure the correct implementation of additive manufacturing techniques within denture-based fabrication workflow.


Subject(s)
Acrylic Resins , Computer-Aided Design , Denture Bases , Materials Testing , Polymethyl Methacrylate , Printing, Three-Dimensional , Denture Bases/microbiology , Polymethyl Methacrylate/chemistry , Acrylic Resins/chemistry , Denture Design , Humans , Feasibility Studies , Dental Materials/chemistry , Dental Bonding/methods , Surface Properties , Stereolithography , Flexural Strength , Hardness , Solubility
4.
Int J Prosthodont ; 37(7): 285-307, 2024 Feb 21.
Article in English | MEDLINE | ID: mdl-38819942

ABSTRACT

PURPOSE: The purpose of this systematic review and meta-analysis was to compare the influence of fabrication method (conventional, subtractive, and additive procedures) and manufacturing trinomial (technology, printer, and material combination) on the marginal and internal fit of cobaltchromium (Co-Cr) tooth-supported frameworks. MATERIALS AND METHODS: An electronic systematic review was performed in five data bases: MEDLINE/PubMed, Embase, World of Science, Cochrane, and Scopus. Studies that reported the marginal and internal discrepancies of tooth-supported Co-Cr additive manufacturing (AM) frameworks were included. Two authors independently completed the quality assessment of the studies by applying the Joanna Briggs Institute Critical Appraisal Checklist for Quasi-Experimental Studies. A third examiner was consulted to resolve lack of consensus. RESULTS: A total of 31 articles were included and classified based on the evaluation method: manufacturing accuracy, the dual- or triple-scan method, stereomicroscope, optical coordinate measurement machine, microCT, profilometer, and silicone replica. Six subgroups were created: 3D Systems, Bego, Concept Laser, EOS, Kulzer, and Sisma. Due to the heterogeneity and limited data available, only the silicone replica group was considered for meta-analysis. The metaanalysis showed a mean marginal discrepancy of 91.09 µm (I2 = 95%, P < .001) in the conventional group, 77.48 µm (I2 = 99%, P < .001) in the milling group, and 82.92 µm (I2 = 98%, P < .001) in the printing group. Additionally, a mean internal discrepancy of 111.29 µm (I2 = 94%, P < .001) was obtained in the conventional casting group, 121.96 µm (I2 = 100%, P < .001) in the milling group, and 121.25 µm (I2 = 99%, P < .001) in the printing group. CONCLUSIONS: Manufacturing method and selective laser melting (SLM) metal manufacturing trinomial did not impact the marginal and internal discrepancies of Co-Cr frameworks for the fabrication of tooth-supported restorations.


Subject(s)
Chromium Alloys , Computer-Aided Design , Humans , Chromium Alloys/chemistry , Dental Marginal Adaptation , Printing, Three-Dimensional , Denture Design , Dental Prosthesis Design , Technology, Dental , Dental Materials/chemistry
5.
J Evid Based Dent Pract ; 24(2): 101986, 2024 06.
Article in English | MEDLINE | ID: mdl-38821651

ABSTRACT

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Digitally versus conventionally fabricated complete dentures: A systematic review on cost-efficiency analysis and patient-reported outcome measures (PROMs). Tew, In Meei, Suet Yeo Soo, and Edmond Ho Nang Pow.The Journal of Prosthetic Dentistry (2023). SOURCE OF FUNDING: No fund was received. TYPE OF STUDY/DESIGN: Systematic review.


Subject(s)
Cost-Benefit Analysis , Denture Design , Denture, Complete , Humans , Computer-Aided Design/economics , Denture Design/economics , Denture, Complete/economics , Patient Reported Outcome Measures , Systematic Reviews as Topic
6.
Comput Biol Med ; 175: 108550, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38701590

ABSTRACT

BACKGROUND AND OBJECTIVE: Complete denture is a common restorative treatment in dental patients and the design of the core components (major connector and retentive mesh) of complete denture metal base (CDMB) is the basis of successful restoration. However, the automated design process of CDMB has become a challenging task primarily due to the complexity of manual interaction, low personalization, and low design accuracy. METHODS: To solve the existing problems, we develop a computer-aided Segmentation Network-driven CDMB design framework, called CDMB-SegNet, to automatically generate personalized digital design boundaries for complete dentures of edentulous patients. Specifically, CDMB-SegNet consists of a novel upright-orientation adjustment module (UO-AM), a dental feature-driven segmentation network, and a specific boundary-optimization design module (BO-DM). UO-AM automatically identifies key points for locating spatial attitude of the three-dimensional dental model with arbitrary posture, while BO-DM can result in smoother and more personalized designs for complete denture. In addition, to achieve efficient and accurate feature extraction and segmentation of 3D edentulous models with irregular gingival tissues, the light-weight backbone network is also incorporated into CDMB-SegNet. RESULTS: Experimental results on a large clinical dataset showed that CDMB-SegNet can achieve superior performance over the state-of-the-art methods. Quantitative evaluation (major connector/retentive mesh) showed improved Accuracy (98.54 ± 0.58 %/97.73 ± 0.92 %) and IoU (87.42 ± 5.48 %/70.42 ± 7.95 %), and reduced Maximum Symmetric Surface Distance (4.54 ± 2.06 mm/4.62 ± 1.68 mm), Average Symmetric Surface Distance (1.45 ± 0.63mm/1.28 ± 0.54 mm), Roughness Rate (6.17 ± 1.40 %/6.80 ± 1.23 %) and Vertices Number (23.22 ± 1.85/43.15 ± 2.72). Moreover, CDMB-SegNet shortened the overall design time to around 4 min, which is one tenth of the comparison methods. CONCLUSIONS: CDMB-SegNet is the first intelligent neural network for automatic CDMB design driven by oral big data and dental features. The designed CDMB is able to couple with patient's personalized dental anatomical morphology, providing higher clinical applicability compared with the state-of-the-art methods.


Subject(s)
Denture, Complete , Humans , Denture Design/methods , Neural Networks, Computer , Computer-Aided Design
7.
Swiss Dent J ; 134(3): 1-17, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38757922

ABSTRACT

The concept of bilateral cantilevers on a single central implant (T-design) for three-unit implant-supported fixed dental prostheses (ISFDPs) has not been explored nor tested. This technical hypothesis aimed to explore the feasibility of such an approach as a cost-effective alternative to conventional treatments. Careful considerations regarding implant diameter, length, ideal position, occlusal scheme, and bone remodeling are essential to ensure adequate support, stability, and prevention of complications. In this proof of concept, we present a preliminary case with this novel design to replace missing posterior teeth in a patient with narrow bone conditions. In addition, a series of planned investigations and preliminary results, including preclinical studies, are presented to illustrate our concept and its potential clinical implications. Clinically, after two-year follow-up, healthy and stable peri-implant tissues around the ISFDP exemplarily demonstrated excellent stability, functionality, and comfort, which is supported by acceptable fracture resistance data in vitro, suggesting indeed the practical potential and suitability. Thus, we claim that such a treatment modality has the at least theoretical potential to revolutionize implant dentistry by providing innovative and cost-effective treatment options for patients with partial ISFDPs in very specific cases. Of course, further research and evaluations are necessary to validate the clinical implications of this innovative hypothesis. Implementing the 3-on-1 T-bridge approach in partial ISFDPs could offer a promising alternative to traditional methods. If proven successful, this technique may lead to significant advancements in clinical practice, providing a less invasive cost-effective treatment option.


Subject(s)
Dental Prosthesis, Implant-Supported , Humans , Dental Prosthesis, Implant-Supported/methods , Proof of Concept Study , Denture, Partial, Fixed , Denture Design , Female
8.
Int J Prosthodont ; 37(7): 159-164, 2024 Feb 21.
Article in English | MEDLINE | ID: mdl-38787580

ABSTRACT

To explore the applications of 3D printing for the fabrication of complete dentures, a literature search was conducted using PubMed to identify articles related to the topic of 3D-printed complete dentures. A search was conducted that included the following keywords: digital complete denture workflow, printed complete denture, additive manufacturing complete denture, digital complete denture, CAD/CAM complete denture. Articles published before 2016 were excluded to increase the relevancy of reporting results. Determining how 3D-printed dentures compare to conventional and milled dentures is important to better understand how they can be used clinically. Material strength, color stability, and denture base adaptation are discussed. Currently, the area of greatest innovation is with printing resins and improving physical and esthetic properties. As with every innovation, multiple generations of materials are created before the gold standard is achieved. While the ideal printed denture material does not currently exist, based on the published research, printed dentures have material strength that meets ISO standards, with denture base adaptation similar to conventionally processed dentures. Clinically, it is likely that printed dentures will have more challenges with fractures, color stability, and staining. However, printed dentures offer many benefits, and the current limitations will be addressed as new materials are developed. We are currently at the beginning of what is an exciting future for printed dentures.


Subject(s)
Denture Design , Denture, Complete , Printing, Three-Dimensional , Humans , Computer-Aided Design
9.
Clin Oral Investig ; 28(6): 330, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38772987

ABSTRACT

OBJECTIVES: The aim of this multi-center pilot study was to assess the viability and feasibility of a novel treatment concept - the canine-positioned single implant mandibular overdenture (c-SIMO), with the single implant placed on the patient's preferred chewing side instead of the midline. MATERIALS AND METHODS: Participants received a single implant in the canine region of their preferred chewing side, based on an Asymmetry Index observed during mastication. The pre-existing mandibular denture was transformed into a c-SIMO on a spherical attachment. The primary outcome was oral health-related quality of life (OHRQoL), measured with GOHAI and OHIP-EDENT. Secondary outcomes included denture satisfaction index (DSI), chewing efficiency (CE), maximum bite force (MBF), implant survival and success, and prosthetic maintenance. Data analysis included descriptive statistics and bivariate comparison tests. RESULTS: Fifteen participants received the c-SIMO treatment (mean age: 69.9 ± 7.0). Implant success and survival rates were 100% at 1 year. Patient-reported outcome measures improved significantly compared to pre-treatment values (OHIP-EDENT: p = 0.001; DSI: p = 0.001; GOHAI: p = 0.002). Masticatory outcomes also improved significantly (CE: p = 0.001; overall MBF: p = 0.005). Post-implant, MBF was significantly higher in the ipsilateral side compared to the contralateral side at 2 weeks (p = 0.019) and 3 months (p = 0.015), but no longer at T3 (p = 0.730). Common prosthodontic events included denture base adjustments (n = 17) and matrix activation (n = 9). CONCLUSIONS: This pilot study concludes that c-SIMO is a promising treatment option, and a potential alternative to the single midline implant overdenture. CLINICAL RELEVANCE: The novel treatment concept of a canine-positioned single implant mandibular overdenture could be a viable treatment alternative to the midline positioning.


Subject(s)
Dental Prosthesis, Implant-Supported , Denture, Overlay , Feasibility Studies , Mastication , Quality of Life , Humans , Pilot Projects , Aged , Male , Female , Mastication/physiology , Cuspid , Dental Implants, Single-Tooth , Patient Satisfaction , Middle Aged , Mandible , Denture Design
10.
Clin Oral Investig ; 28(6): 320, 2024 May 16.
Article in English | MEDLINE | ID: mdl-38750145

ABSTRACT

OBJECTIVES: The purpose of this scoping review was to identify different methods employed for recording the maxillomandibular relationship (MMR) for computer-aided designed and manufactured (CAD-CAM) complete dentures (CDs). MATERIALS AND METHODS: This scoping review followed the PRISMA-ScR guidelines and was developed according to Arksey and O'Malley and The Joanna Briggs Institute protocol. The methods were registered on the Open Science Framework (< osf.io/rf4xm> ). The focus question was: "What are the different techniques for recording the maxillomandibular relationship in the digital workflow used in CECDs?" Two investigators searched 3 online databases [MEDLINE (PubMed), Scopus, and Science Direct] independently. The inclusion criteria were clinical studies and reviews that assessed techniques for recording MMR using digital workflow for manufacturing of CECDs. A descriptive analysis was performed considering the study design, manufacturing system, clinical steps, and tools for the determination of MMR, and the difficulty level of procedures. RESULTS: 4779 articles were identified in the electronic search and 10 studies were included for data analysis. The review identified 4 commercially available CAD-CAM denture systems and 3 innovative methods suitable for abbreviating the number of appointments (2 to 4 visits). The trial denture is inherent to the procedure for the Baltic System and 3 innovative techniques. Three techniques (2 innovative and WholeYouNexteeth) demonstrated lower difficulty levels for performing the clinical procedures, regardless of the professional skills. CONCLUSIONS: The commercially available and innovative techniques for the recording of MMR may provide predictability of the treatment. The techniques are effective, however, rely on the learning curve and the patient's clinical condition. CLINICAL RELEVANCE: Recording of the maxillomandibular relationship is paramount for the manufacturing and functionality of complete dentures. Clinicians should be aware of the different tools and techniques described for registering the jaw relationship.


Subject(s)
Computer-Aided Design , Denture Design , Denture, Complete , Humans , Denture Design/methods , Jaw Relation Record/methods
11.
BMC Oral Health ; 24(1): 473, 2024 Apr 19.
Article in English | MEDLINE | ID: mdl-38641783

ABSTRACT

BACKGROUND: The establishment of good facial esthetics is one of the main objectives of complete denture construction. Unfortunately, it may be the caused issue for patients having a prominent premaxilla due to excessive lip support by the labial flange of the maxillary denture. Open-face dentures (OFD) may suggest suitable prosthetic management for these patients. However, clinical evidence regarding the efficiency of OFD is scarce. METHODS: A total of 38 completely edentulous participants having prominent premaxilla and skeletal class I Angle's classification were enrolled in this study. Each participant received a mandibular complete denture and 2 opposing maxillary dentures; conventional (CD) and open-face (OFD). On the day of denture insertion, the participants were divided into 2 groups; CD-OFD and OFD-CD where CD-OFD group was instructed to use the mandibular denture and the maxillary CD for 3 months and then to use the maxillary OFD for another 3 months after a wash-out period of 2 weeks. While group OFD-CD was instructed to use the mandibular denture and the maxillary OFD for 3 months then to use the maxillary CD for another 3 months after a wash-out period of 2 weeks. The dislodging force of the maxillary dentures was evaluated using the universal testing machine and the patient perception of retention, esthetics, and comfort was evaluated using the Visual Analogue Scale (VAS). Evaluation was carried out 1 day, 1 month, and 3 months after denture insertion. The Student t-test was used to compare the 2 maxillary dentures and the intervals for each denture were compared by using the ANOVA test with repeated measures followed by a Post Hoc test (adjusted Bonferroni) for pairwise comparison. RESULTS: The significance of the obtained results was judged at the 5% level (P value). The dislodging force and patient perception of retention did not show significant differences between the 2 dentures, while the perception of esthetics showed significant differences throughout the follow-up period. Perception of comfort showed an insignificant difference only at the 3-month interval. CONCLUSIONS: Open-face maxillary dentures can be a suitable alternative for patients with prominent premaxilla to achieve satisfactory retention, aesthetics, and comfort.


Subject(s)
Denture, Complete, Upper , Mouth, Edentulous , Humans , Cross-Over Studies , Denture Design/methods , Denture, Complete , Denture Retention , Patient Satisfaction
12.
Int J Prosthodont ; 37(2): 157-165, 2024 04 22.
Article in English | MEDLINE | ID: mdl-38648164

ABSTRACT

PURPOSE: To generate data on the long-term survival of metal-ceramic resin-bonded fixed partial dentures (RBFPDs). MATERIALS AND METHODS: A total of 89 patients received 94 RBFPDs, 5 of whom (women n = 1; men n = 4) received 2 RBFPDs each. All RBFPDs were fabricated as two-retainer end-abutment metal-ceramic restorations. Clinical follow-ups were performed 6 months after cementation and then annually thereafter. The mean observation time was 7.5 years. Cox regression was performed to test the effects of the variables: gender, location, arch, design, use of rubber dam, and adhesive luting system. Survival and success were calculated using Kaplan-Meier curves. As a secondary objective, patient and dentist satisfaction with the esthetics and function of the RBFPDs was evaluated. The significance level was set at α = .05 for all calculations. RESULTS: Estimated Kaplan-Meier failure-free survival was 97.5% (standard error [SE] 1.7) after 5 years and 83.3% (SE 5.3) after 10 years. Calculated intervention-free survival (success) was 90.1% (SE 3.4) after 5 years and 65.5% (SE 6.7) after 10 years. Debonding-free survival was 92.6% (SE 2.9) after 5 years and 80.6% (SE 5.4) after 10 years. Cox regression revealed that none of the four tested variables had a significant effect on the incidence of complications in RBFPDs. Patient and dentist satisfaction with RBFPD esthetics and function was consistently high throughout the observation period. CONCLUSIONS: Within the limitations of an observational study, RBFPDs achieved clinically successful outcomes over a mean observational period of 7.5 years.


Subject(s)
Denture, Partial, Fixed, Resin-Bonded , Humans , Female , Male , Middle Aged , Dental Restoration Failure , Metal Ceramic Alloys/chemistry , Adult , Denture Design , Patient Satisfaction , Aged , Esthetics, Dental
13.
Int J Prosthodont ; 37(2): 173-180, 2024 04 22.
Article in English | MEDLINE | ID: mdl-38648165

ABSTRACT

PURPOSE: To evaluate the marginal integrity of three inlay-retained fixed dental prosthesis (IRFDP) designs fabricated using monolithic zirconia. MATERIALS AND METHODS: In total, 30 IRFDPs were fabricated using 4-YTZP monolithic zirconia and randomly divided into three groups according to the cavity design. Groups ID2 and ID1.5 received an inlay cavity preparation, which includes a proximal box and an occlusal extension with a depth of 2 mm or 1.5 mm, respectively. Group PB received a proximal box cavity preparation without an occlusal extension. The restorations were fabricated and cemented using a dual-cure resin cement (Panavia V5) and subjected to an equivalent of 5 years of aging. The specimens were evaluated under an SEM to measure marginal continuity before and after the aging process. RESULTS: During the whole 5-year aging process, no specimens showed signs of cracking, fracture, or loss of retention in any restorations. In the SEM analysis, most marginal defects observed in the restorations were areas of microgaps at the tooth/cement interface (TC) or zirconia/cement interface (ZC), resulting in loss of adaptation. There was a significant difference between the groups after the aging process at both the TC (F = 4.762, P < .05) and ZC (F = 6.975, P < .05), with Group ID2 presenting the best performance. There was a significant difference between TC and ZC in all groups (P < .05), with ZC presenting more gaps in all groups. CONCLUSIONS: Inlay cavity designs including a proximal box and an occlusal extension exhibited better marginal stability than a proximal box without occlusal extension.


Subject(s)
Inlays , Zirconium , Zirconium/chemistry , Humans , In Vitro Techniques , Dental Marginal Adaptation , Dental Prosthesis Design , Denture Design , Denture, Partial, Fixed , Dental Materials/chemistry
14.
J Prosthet Dent ; 131(5): 933.e1-933.e7, 2024 May.
Article in English | MEDLINE | ID: mdl-38429151

ABSTRACT

STATEMENT OF PROBLEM: The connector height and retainer occlusal thickness of fixed partial dentures (FPDs) may affect restoration longevity. PURPOSE: The purpose of this in vitro study was to determine and compare the fracture resistance of 4-unit monolithic 5% yttria tetragonal zirconia polycrystal (5Y-TZP) FPDs made with different connector heights and retainer occlusal thicknesses after thermomechanical aging. MATERIAL AND METHODS: Forty test metal dies were duplicated from a master metal die containing 2 anatomic abutment preparations of the mandibular right first premolar and second molar for a 4-unit FPD. The dies were divided into 2 groups of 20 each for the fabrication of 4-unit FPDs, with 2-mm and 4-mm uniform connector heights at all 3 connectors, resulting in 6.3-mm2 and 12.6-mm2 connector areas. Each of these groups was further divided into 2 subgroups based on the occlusal thickness of the 2 retainers of 1 mm and 2 mm (n=10). Polyvinyl siloxane impressions of the test metal dies were made and poured in Type V dental stone. Laboratory scans were performed on all the stone dies, and 40 5Y-TZP FPDs (Ceramill Zolid FX) were designed and fabricated. Subsequently, all the FPDs were luted on to the metal dies with a self-adhesive resin cement. The FPDs were preloaded (400 000 mechanical cycles; 4000 thermocycles) using a mastication simulator and tested for axial compressive strength. Two-way analysis of variance (ANOVA) was used to examine the effect of connector and occlusal thicknesses on the fracture load (α=.05). The data were further assessed using the post hoc Tukey HSD multiple comparison test (α=.05). RESULTS: The mean fracture load values were between 737 N and 1563 N. Significant differences in the mean fracture load were found between the connector heights (601 N; P<.001) and occlusal thicknesses (225 N; P=.002), but the interaction of the 2 factors was not significant (P=.132) The Tukey post hoc analysis showed significant differences between the connector thicknesses groups (P<.01), but the occlusal thicknesses were found to be similar for the same connector height (P=.609) CONCLUSIONS: Connector height and occlusal retainer thickness influenced the fracture load of 4-unit monolithic 5Y-TZP FPDs after thermomechanical aging.


Subject(s)
Dental Stress Analysis , Denture Design , Denture, Partial, Fixed , Yttrium , Zirconium , Zirconium/chemistry , Yttrium/chemistry , Dental Restoration Failure , Humans , Materials Testing , In Vitro Techniques , Dental Materials/chemistry , Dental Abutments
15.
J Prosthet Dent ; 131(6): 1252.e1-1252.e10, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38553302

ABSTRACT

STATEMENT OF PROBLEM: The difference in chemical composition between denture base resin and denture teeth requires the development of bonding protocols that increase the union between the materials. PURPOSE: The purpose of this in vitro study was to evaluate the impact of different bonding protocols on the bond between heat-polymerized and 3-dimensionally (3D) printed acrylic resin denture bases and acrylic resin prefabricated and 3D printed artificial teeth. MATERIAL AND METHODS: Four types of artificial teeth were evaluated: prefabricated acrylic resin (VITA MFT) and 3D printed (Cosmos TEMP, PRIZMA 3D Bio Denture, and PrintaX AA Temp) bonded to 20×24-mm cylinders of heat-polymerized (VipiWave) and 3D printed (Cosmos Denture, PRIZMA 3D Bio Denture, and PrintaX BB Base) denture bases. Three bonding protocols were tested (n=20): mechanical retention with perforation + monomer (PT1), mechanical retention with perforation + airborne-particle abrasion with 50-µm aluminum oxide + monomer (PT2), and mechanical retention with perforation + Palabond (PT3). Half of the specimens in each group received 10 000 thermocycles and were then subjected to the bonding test at a crosshead speed of 1 mm/minute. The failure type was analyzed and scanning electron micrographs made. Additionally, surface roughness (Ra) and wettability (degree) were analyzed (n=15). ANOVA was used to evaluate the effect of the bonding protocol, and the Student t test was applied to compare the experimental groups with the control (α=.05). For type of failure, a descriptive analysis was carried out using absolute and relative frequency. The Kruskal-Wallis test was used to evaluate the surface changes (α=.05). RESULTS: Among the protocols, PT3 with in Yller and PT2 with Prizma had the highest bond strengths of the heat-polymerized denture base and 3D printed teeth (P<.05). When comparing the experimental groups with the control, PT3 and PT2 had greater union with the 3D printed denture base + 3D printed teeth (in Yller), with no difference from the heat-polymerized denture base + prefabricated teeth in acrylic resin. The treatment of the 3D printed tooth surfaces affected the surface roughness of Prizma (P<.001) and wettability (P<.001). CONCLUSIONS: To increase the bond between Yller 3D printed denture base + 3D printed teeth, a bonding protocol including mechanical retention with perforation + Palabond or mechanical retention with perforation + airborne-particle abrasion with aluminum oxide + monomer is indicated. For the other materials tested, further bonding protocols need to be investigated.


Subject(s)
Acrylic Resins , Dental Bonding , Denture Bases , Printing, Three-Dimensional , Tooth, Artificial , Acrylic Resins/chemistry , Dental Bonding/methods , In Vitro Techniques , Materials Testing , Surface Properties , Humans , Dental Materials/chemistry , Denture Design
16.
Br Dent J ; 236(6): 490, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38519686
17.
Gerodontology ; 41(2): 305-309, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38422399

ABSTRACT

OBJECTIVE: To describe the clinical procedures of complete denture set fabrication in three appointments. BACKGROUND: Simplified approaches have proven not to be inferior to conventional ones in terms of quality, patient satisfaction and masticatory ability. MATERIALS AND METHODS: The patient was a 77-year-old edentulous adult with mobility impairment seeking dental rehabilitation in a small number of appointments due to commuting difficulties. RESULTS: A set of complete dentures was delivered within three appointments. The second appointment was dedicated to set-up trial due to the patient's aesthetic demands. CONCLUSION: Under certain circumstances and after a thorough study of each case, dental clinicians may propose the fabrication of complete dentures in a three-appointment protocol incorporating a set-up trial session.


Subject(s)
Denture Design , Denture, Complete , Humans , Aged , Mouth, Edentulous/rehabilitation , Mobility Limitation , Male , Female , Appointments and Schedules , Dental Impression Technique
19.
J Prosthodont Res ; 68(1): 78-84, 2024 Jan 16.
Article in English | MEDLINE | ID: mdl-36990752

ABSTRACT

Purpose To evaluate and compare the survival, success rates, and biological and technical complications of three-unit posterior monolithic and veneered zirconia and metal-ceramic (MC) posterior fixed partial dentures (FPDs) fabricated using a digital workflow and computer-aided design and computer-aided manufacturing (CAD/CAM) over a 5-year follow-up.Methods Ninety patients in need of three-unit posterior FPDs were randomized to receive monolithic zirconia (MZ), veneered zirconia (VZ), and MC restorations (n = 30 each). Teeth preparations were scanned using an intraoral scanner, and restorations were milled and cemented with resin cement. Clinical performance and periodontal parameters were assessed at baseline and yearly up to 5 years after insertion. Data analysis was performed using the Kaplan-Meier method, Friedman test, and Wilcoxon signed-rank test with Bonferroni correction and Mann-Whitney U test.Results The 5-year survival rates of the MZ, VZ, and MC FPDs were 87%, 97%, and 100%, respectively (P = 0.04). Most complications were biological in nature. Only one MZ FPD fractured 58 months after placement. All the restorations were assessed as satisfactory at each recall. Differences were found in the gingival index score over time in the VZ and MC groups. The margin index remained stable throughout the follow-up period in both zirconia groups.Conclusions The results of this study suggest that using a digital workflow to fabricate posterior FPDs is an adequate treatment option and that monolithic zirconia could be a viable alternative to metal-ceramic or veneered zirconia. However, further long-term studies are necessary to provide stronger evidence in patients with bruxism.


Subject(s)
Dental Restoration Failure , Denture Design , Humans , Prospective Studies , Workflow , Ceramics , Zirconium , Denture, Partial, Fixed , Computer-Aided Design , Dental Porcelain
20.
Spec Care Dentist ; 44(1): 124-129, 2024.
Article in English | MEDLINE | ID: mdl-37013961

ABSTRACT

OBJECTIVE: To present clinical strategies for prosthetic rehabilitation with complete dentures (CDs) of a Parkinson's disease patient. CASE REPORT: An 82-year-old patient sought the Department of Dentistry at UFRN, reporting retention dissatisfaction and hamper to the mandibular CD adaptation. Patient-reported a dry mouth sensation, and exhibited disordered mandibular movements, tremors, and resorbed mandibular ridge. Aiming retention and stability, double molding with zinc enolic oxide impression paste, neutral zone technique, and non-anatomic teeth were proposed as clinical strategies. At delivery, identification and relief in the supercompression areas were performed to facilitate the acceptance and use of the new dentures. CONCLUSION: The strategies promoted patient satisfaction regarding retention, stability, and comfort. This treatment may be considered for the rehabilitation of Parkinson's disease patients, favoring the adaptation process.


Subject(s)
Parkinson Disease , Humans , Aged, 80 and over , Parkinson Disease/complications , Denture Design/methods , Denture Retention/methods , Denture, Complete , Patient Satisfaction
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