A CAD/CAM Zirconium Bar as a Bonded Mandibular Fixed Retainer: A Novel Approach with Two-Year Follow-Up.
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ABSTRACT:
SUBMITTER: Zreaqat M
PROVIDER: S-EPMC5551476 | biostudies-other | 2017
REPOSITORIES: biostudies-other
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Project description:BackgroundCAD/CAM (computer-aided design/computer-aided manufacturing) fixed retainers (FRs) as an alternative to multistranded FRs to maintain orthodontic treatment outcome.ObjectivesThe primary aim was to compare CAD/CAM versus conventional multistranded FRs in terms of stability until 2 years. Secondary outcomes were failure rates, patient satisfaction, and cost-minimization.Trial design2-arm parallel, two-centre randomized controlled trial.MethodsPatients were randomized to CAD/CAM or conventional FRs in both arches, in a 1:1 ratio and blocks of four. Allocation concealment was secured by using sequentially numbered envelopes. Patients were blinded. FRs were bonded at the end of treatment, and patients were recalled after 12 and 24 months. First-time retainer failures were recorded and digital impressions were taken. Arch widths and lengths, as well as Little's Irregularity Index (LII), were measured. Additionally, patients answered satisfaction questionnaires. Linear mixed models were applied for measurements and patient satisfaction. Survival analyses were estimated with Kaplan-Meier curves, along with Cox-regression modelling. Cost-minimization analysis was undertaken.ResultsOne hundred and eighty-one patients were randomized (98 in Centre 1, and 83 in Centre 2): 90 in CAD/CAM and 91 in conventional group. One hundred and fifty three patients attended T24 follow-up. There were no significant differences in LII and arch dimensions between groups for failure-free patients. Within 24 months, 34% maxillary CAD/CAM FRs and 38% maxillary conventional FRs failed, along with 42% mandibular CAD/CAM FRs and 40% mandibular conventional FRs, with no significant difference in survival between groups (hazard ratios conventional to CAD/CAM: maxillary arch: 1.20 [P = 0.46], mandibular arch: 0.98 [P = 0.94]). There were no significant differences in patient satisfaction between groups. No harms were observed. Cost-minimization analysis showed that CAD/CAM FRs were slightly cheaper than conventional FRs.ConclusionsThere were no clinically significant differences in LII, arch widths, and lengths between CAD/CAM and conventional FRs after 24 months. There were no differences in failures and patient satisfaction between groups. CAD/CAM FRs were slightly cheaper than conventional FRs.Trial registrationClinicalTrials.gov NCT04389879.
| S-EPMC10888518 | biostudies-literature
Project description:In reconstructions of mandibles and condyles, free fibular flaps and metallic condylar heads (CH) are often used after resection. However, in conventional reconstructions, it is difficult to fix the metallic CH on the same preoperative position because the position is determined visually. Therefore, we have made an original computer-aided design and manufacture (CAD/CAM) guide for mandibular condyle reconstruction, combining a metallic CH with a free fibular flap. A 71-year-old woman with gingival carcinoma underwent hemimandibulectomy. We reconstructed the mandible and condyle with a metallic CH and a free fibular flap. We placed a mark on the CAD/CAM guide showing the correct position for fixing the CH to the fibular blocks. We also designed a surface for attaching to the healthy edge of the mandible. The fibular blocks and metallic CH were fixed as 1 unit before separating the flap from the leg and replacing the diseased tissue. Reconstruction was completed by fixing the attachment surface to the healthy side of the mandible. The guide marks solved the difficulty of conventional reconstruction; during surgery, we fixed the metallic CH to the same position as the original bone using these marks. The postoperative deviation of the condyle from the virtual plan was 4.3 mm, whereas the reported deviation of such prostheses was 3.8 mm (range 1.3-6.7); so our guide was acceptably accurate. Furthermore, it appears that the CAD/CAM guide is more useful for reconstruction after hemimandibulectomy including the condyle than after segmental resection without including condyle.
| S-EPMC7544273 | biostudies-literature
Project description:ObjectivesThe purpose of this randomized clinical trial was to compare the required time of potential clinical adjustments of posterior screw-retained monolithic zirconia implant retained crowns based on intraoral optical scanning (IOS) or conventional impressions.Materials and methodsPatients with posterior tissue level implants (Straumann RN) replacing solitary teeth were recruited. Of all patients, impressions were taken with both an IOS (3M™ TDS) and a conventional (polyether) pick-up impression. Randomization was performed after impression taking and patients were to receive either a crown based on the digital or the conventional impression. The time required for adjustments at placement was recorded. Additionally, restoration survival and mechanical complications with a follow-up of one year were documented.ResultsThirty two patients with 45 implants were included: 23 restorations in the test (IOS) and 22 in the control (conventional) group. The average adjustment time was 3.35 min (SD ± 3.38, range: 0-11 min) for the digital versus 6.09 min (SD ± 4.63, range: 0-18 min) for the conventional impressions (p = .039). A proper fit (no adjustments required) was achieved 39,1% in the digital and 18,2% conventional group respectively. All 45 restorations could be placed within the two planned appointments and only two minor mechanical complications occurred during the first year of function.ConclusionsThe use of IOS resulted in shorter adjustment times at try-in than conventional impressions for solitary CAD/CAM implant restorations. Screw-retained solitary monolithic zirconia restorations on ti-base abutments show low complication- and survival rates in the short term.
| S-EPMC8453558 | biostudies-literature
Project description:PurposeTo prospectively assess long-term (20?year) clinical, radiographic, and patient-reported outcomes of an elderly population provided with mandibular implant-supported overdentures.Materials and methodsA total of 53 elderly (aged ?60?years at the time of treatment) were provided with two endosseous implants supporting a mandibular overdenture and a conventional maxillary denture. Outcome parameters-including implant loss, plaque index, gingival index, bleeding index, presence of calculus, probing depth, and satisfaction with implant-supported overdenture-were scored 1, 5, 10, and 20?years after prosthetic treatment. Radiographic analysis was performed to assess peri-implant bone changes. At the 20-year evaluation, frailty (Groningen Frailty Index) and quality of life (EuroQol 5D) were additionally assessed.ResultsA total of 15 patients completed the 20-year follow-up. The 20-year implant survival rate was 92.5%. Plaque index, bleeding index, and probing depth increased slightly over time, while gingival index and presence of calculus remained unchanged. Radiographic analysis revealed minor marginal bone loss during the first 10 years and no further loss thereafter. Participants were very satisfied with their prosthesis and reported a good quality of life. At the 20-year evaluation, 64.3% of the patients were classified as frail.ConclusionsThe long-term survival of implants supporting a mandibular overdenture is high. Although most elderly in the study became frail over time, peri-implant health and marginal bone level remained at a satisfactory level.
| S-EPMC6767521 | biostudies-literature
Project description:BACKGROUND:Reconstruction of mandibular continuity and function after tumor resection is challenging, particularly in cases including the mandibular condyle. Various approaches for reconstruction after disarticulation resection have been reported. However, the scapula flap has received little attention as a treatment option in these cases. PATIENTS AND METHODS:Three cases of computer aided design and computer aided manufacturing (CAD/CAM) assisted reconstruction after disarticulation resection using a vascularized scapula and latissimus dorsi flap are reported. All cases required reconstruction of the mandibular ramus and condyle in combination with the reconstruction of large and complex soft tissue defects. RESULTS:The surgical procedure was deemed successful in all cases. The scapula flap could be placed as preoperatively planned and patients regained their preoperative occlusion pattern and satisfying mouth opening-ranges. The large soft tissue defects could reliably be reconstructed using a latissimus dorsi flap. CONCLUSIONS:The scapula and latissimus dorsi flap can be considered a suitable option for the reconstruction of mandibular disarticulation resection defects in combination with large soft tissue defects.
| S-EPMC6595593 | biostudies-literature
Project description:Abstract: The present study aimed to assess the eighteen month follow-up patient-centered outcomes of a simple and predictable protocol for 3D-printed functional complete dentures manufactured using an improved poly(methyl methacrylate) (PMMA)-nanoTiO2. A detailed morphological and structural characterization of the PMMA-TiO2 nanocomposite, using SEM, EDX, XRD, and AFM, after 3D-printing procedure and post-wearing micro-CT, was also performed. METHODS:A total of 35 fully edentulous patients were enrolled in this prospective study. A 0.4% TiO2-nanoparticle-reinforced PMMA composite with improved mechanical strength, morphologically and structurally characterized, was used according to an additive computer-aided design and computer-aided manufacturing (CAD/CAM) protocol for complete denture fabrication. The protocol proposed involved a three-step appointment process. Before denture insertion, 1 week, 12 month, and 18-month follow up patients were evaluated via the Visual Analogue Scale (VAS, 0-10) and Oral Health Impact Profile for Edentulous Patients (OHIP-EDENT), with a higher score meaning poor quality of life. RESULTS:A total of 45 complete denture sets were inserted. OHIP-EDENT scored significantly better after 18 months of denture wearing, 20.43 (±4.42) compared to 52.57 (±8.16) before treatment; mean VAS was improved for all parameters assessed. CONCLUSIONS:Within the limitations of this study, we can state that the proposed workflow with the improved material used is a viable treatment option for patients diagnosed with complete edentulism.
| S-EPMC7073708 | biostudies-literature
Project description:The aim of this study was to evaluate the fracture resistance of 2 different types of all-ceramic crown using immediate dentin sealing (IDS), obtained using a CAD/CAM system on molars with different preparations. Forty extracted lower molars were endodontically treated and divided into four groups (n = 10) according to the dental preparation. Group 1 (SP0) was prepared without filling the pulp chamber and crown-root junction was located at the cementoenamel junction (CEJ). Group 2 (SP1) was prepared without filling the pulp chamber and crown-root junction was located 1-mm above the CEJ. Groups 3 and 4 contained a flat preparation surface with no axial wall height. Group 3 (CP0) was made IDS with complete filling of the pulp chamber with composite resin and crown-root junction was located at the CEJ. Group 4 (CP1) was prepared with complete filling of the pulp chamber and crown-root junction was located 1-mm above the CEJ. All groups were restored with CAD/CAM lithium disilicate ceramic crowns. Specimens were subjected to the fracture test and statistically analyzed using analysis of variance (ANOVA). Fracture mode was determined using a stereoscopic microscope, classified as repairable or nonrepairable, and analyzed using Fischer's exact test. Results indicated that there were no significant differences between the groups in terms of fracture resistance or fracture pattern (p >0.05). Fracture resistance was the lowest in the SP0 group, followed by the SP1 group (1634.38 N) of CP0 (1821.50 N), and it was the highest in the CP1 group. There was a predominance of nonrepairable fractures and there were no significant differences in the fracture resistance and fracture mode of CAD/CAM lithium disilicate molar all-ceramic crowns. Endodontically treated molars teeth might be restored with endocrowns or all-ceramic crowns on flat preparation; however tooth fracture failures that affect reliability of these types of restorations should be considered.
| S-EPMC6535888 | biostudies-literature
Project description:This systematic review aimed to study the outcomes of CAD-CAM (milled and 3D-printed) interim dental prostheses when compared to conventional ones. The focused question of "In natural teeth, what are the outcomes of CAD-CAM interim FDPs compared to the conventionally-manufactured ones regarding marginal fit, mechanical properties, esthetics, and color stability" was formulated. The systematic search was conducted electronically in the PubMed/MEDLINE, CENTRAL, EMBASE, Web of Science, New York Academy of Medicine Grey Literature Report, and Google Scholar databases by using the MeSH keywords and keywords associated with the focused question and limiting articles to those published between 2000 and 2022. A manual search was conducted in selected dental journals. The results were analyzed qualitatively and are presented in table format. Of the included studies, 18 studies were in vitro and 1 was a randomized clinical trial. Of the eight studies analyzing the mechanical properties, five studies favored the milled interim restorations, one study favored both 3D-printed and milled interim restorations, and two studies reported better mechanical properties in conventional interim restorations. Among four studies evaluating the marginal discrepancies, two studies favored the marginal fit in milled interim restorations, one study reported a better marginal fit in both milled and 3D-printed interim restorations, and one study found conventional interim restorations have a better marginal fit and smaller marginal discrepancy when compared to both milled and 3D-printed restorations. Among five studies that evaluated both the mechanical properties and marginal fit, 1 study favored 3D-printed interim restorations and four studies favored milled interim restorations over the conventional ones. Two studies analyzing the esthetics outcomes demonstrated better results with milled interim restorations compared to conventional and 3D-printed interim restorations in terms of their color stabilities. The risk of bias was low for all the studies reviewed. The high level of heterogeneity within the studies excluded meta-analysis. Most of the studies favored the milled interim restorations over the 3D-printed and conventional restorations. The results suggested that milled interim restorations offer a better marginal fit, higher mechanical properties, and better esthetic outcomes in terms of color stabilities.
| S-EPMC10004428 | biostudies-literature
Project description:Acid resistance of CAD/CAM resin composites. Erosion-related tooth surface loss is closely related to acid exposure, such as contact with acidic beverages or disease-related reflux. As a result, dental restorations in affected patients are also exposed to acids, which indicates that the performance and longevity of a dental restoration is impacted by the acid resistance of the individually employed restorative materials. However, unlike for ceramic materials, the acid resistance of CAD/CAM resin composites is not commonly evaluated by the manufacturers, and no standardised test methods have yet been established. Against this background, the present in vitro study aimed to examine the long-term resistance of CAD/CAM resin composites (Brilliant Crios, Cerasmart, Grandio blocs, Lava Ultimate, Shofu Block HC) against three acidic media (tonic water, acetic acid, hydrochloric acid) as well as demineralized water and to investigate potential damage mechanisms. Changes in surface roughness (Sa) were detected by confocal laser scanning microscopy (CLSM), and changes in surface hardness were measured using Vickers hardness (HV). The damage mechanisms were analysed by scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) and micro X-ray computer tomography (µXCT). For each material, few changes in either Sa or HV were identified for at least one of the different media; for Cerasmart, the sharpest deterioration in surface properties was observed. SEM-EDS revealed leaching of barium, aluminium, and titanium from fillers in a 2 µm zone on the rough but not on the polished surface of the specimen. Within the limitations of the current study, it can be concluded that polished CAD/CAM resin composites can be recommended for clinical use in patients with erosive conditions.
| S-EPMC9220078 | biostudies-literature
Project description:Sarcoidosis + Follow-up 6 month after Keywords = sarcoidosis Keywords = follow-up Keywords: other
2005-01-18 | GSE1907 | GEO