1,720,967 research outputs found
A Randomized Controlled Clinical Trial on Lithium Disilicate Veneers Manufactured by the CAD–CAM Method: Digital Versus Hybrid Workflow
Get PDFPressed lithium disilicate is largely used for veneer manufacturing, but a new block formulation has recently been released on the market. This study evaluated the clinical performance of milled lithium disilicate veneers (LiSi Block, GC Co., Tokyo, Japan) realized with a fully digital or hybrid workflow using modified United States Public Health Service (USPHS) evaluation criteria and survival rates after 24 months of clinical service together with the patient’s satisfaction using the Visual Analog Scale (VAS). A total of 105 veneers on natural anterior teeth were made on twenty-nine patients with LiSi Block (GC, Tokyo, Japan). Patients were randomly divided into three groups: Group 1, 35 veneers realized with a completely digital workflow using Trios 3 (3Shape A/S, Copenhagen, Denmark); Group 2, 35 veneers realized with a completely digital workflow using Experimental IOS (GC, Tokyo, Japan); and Group 3, 35 veneers realized with a hybrid workflow. The restorations were followed up for 24 months, and the modified USPHS evaluation was performed at baseline, 12 months, and 24 months together with periodontal evaluation. Repeated measures two-way ANOVA and the Tukey test were applied to compare the modified USPHS method values (α = 0.05). STATISTICA 10.0 software and SIGMAPLOT 12.0 software were used to perform statistical analysis. There were no statistically significant differences between the three groups and with the interaction of group vs. time periods. The satisfaction scores of 7.35 ± 1.8 and 9.4 ± 0.37 were recorded before and after treatment, respectively. Milled lithium disilicate veneers showed a good clinical outcome after 2 years of clinical service. No difference was found between fully digital or hybrid workflow
Microleakage of three different combinations of adhesive and composite resins
Get PDFAims The aim of the present in vitro study was to evaluate the influence of 3 adhesive systems on microleakage of direct composite restorations with proximal margins under the cement-enamel junction (CEJ) and in the enamel. Materials and methods In 30 extracted molars standardized MOD (mesio-occlusal-distal) cavities were prepared with a proximal margin located 1 mm under the cement-enamel junction and another one in the enamel, and subsequently randomly divided in 3 groups of 10 using 3 different adhesives and the same composite: Flowable (G-aenial Universal Injectable, GC) + universal adhesive (G2-Bond Universal, GC) with selective-etch technique (Group 1); Flowable (G-aenial Universal Injectable, GC) + self-etch adhesive (Clearfil SE Bond 2, Kuraray) with 2-step technique (Group 2); Flowable (G-aenial Universal Injectable, GC) + total-etch adhesive (Optibond FL, Kerr) with 3-step technique (Group 3). Samples were tested for microleakage using silver nitrate and infiltration was classified in 5 levels. The differences in microleakage were statistically evaluated with significance set at p<0.05. Results In the margin located in the enamel, group 1 showed an average of 0 microleakage, group 2 an average of 0.2 and group 3 an average of 0.1. In the margin located in the dentin, group 1 showed an average score of 1.1, group 2 of 2.15 and group 3 of 1.25. No statistically significant difference was found in the enamel. Conclusion The combination of adhesive G2-Bond Universal and Optibond FL showed the highest sealing ability both in margins located in the enamel and margins located in the dentin. The adhesive interface in the enamel produced a very good seal, while the adhesive interface in the dentin showed varying degrees of microleakage in all groups
Outcomes evaluation of a patient treated with roots immediate digital denture: Patient evaluation after full digital dentures
Get PDFThe immediate dentures fabrication in the analogic manner may be an hight timeconsuming and unreliable procedure. The purposes of this article were both to describe a simplified protocol based on a digital workflow used to fabricate a set of immediate dentures and to report patient functional and quality of life data. The digital intraoral scans were recorded and used for dentures design, the teeth arrangement proposed by the software was superimposed to patient frontal photo in order to simulate the aesthetic proposal. The resulted Standard Tessellation Language files were exported to a milling machine for denture fabrication. After immediate denture delivery the remaining lower canine roots were used to retain the prosthesis. In order to evaluate the different effects of the treatment on masticatory efficiency, bite force and health- related quality of life (OHRQoL) data were measured before and after treatment. The patient reported a good adaptation form the delivery, an improvement for all the aspects evaluated after prostheses roots anchorage
RCT on posterior partial crowns made by two different lithium disilicate materials: 8-year results
Get PDFBackground This trial wants to evaluate the clinical behavior of two lithium disilicate systems after 8 years of clinical service. Methods 60 patients in need of receiving a partial adhesive crown on natural abutment posterior teeth were made. 60 restorations were realized. Sample crowns were divided into two groups: Group 1 IPS e.max press (Ivoclar-Vivadent, Schaan, Liechtenstein), and Group 2 Initial LiSi press (GC Co., Tokyo, Japan). The restorations were followed up for 8 years, and the FIT evaluation was used FOR each recall to evaluate their clinical performances. Accordingly, with the FIT system, 7 clinical parameters (Interproximal, Occlusion, Design, Mucosa, Bone, Biology and Margins) WERE evaluated, using a 0–1-2 scoring scheme, by an oral radiograph and occlusal and buccal pictures. Statistical analysis was made using Mann-Whitney 'U' test and the level of significance was set at p < 0.05. Also, the "success" of the crowns (restoration in place without any biological or technical complication) and "survival" (restoration still in place with biological or technical complication) were evaluated. Results Regarding FIT scores, when compared to the 3-years results all partial crowns showed a slight decrease in scores, mainly due to bone loss of alveolar crest in the radiographic evaluation and consequent recession of gingival tissue. Similarly happened to several partial crowns of both groups about interproximal contact parameters, were also related to a modification of the contour of the crowns. Any way all evaluated parameters showed high scores, and no statistically significant differences were noted between the two groups in any of the assessed variables (p > 0.05). All FIT scores were compatible with the outcome of clinical success no one restoration was replaced or repaired and the survival and success rate were 100%. Conclusions The two groups of lithium disilicate systems showed similar results after 8 years of clinical service and no statistically significant differences were found. Both systems were shown to be clinically predictable and reliable
A randomized controlled clinical trial on press and block lithium disilicate partial crowns: A 4-year recall
No full textFlexural Strength Analysis of Different Complete Denture Resin-Based Materials Obtained by Conventional and Digital Manufacturing
Get PDFPMMA (Polymethylmethacrylate) is the material of choice to fabricate denture bases. Recently, with the introduction of CAD-CAM and 3D printers in dentistry, new materials have been proposed for complete denture manufacturing. Aim: This study compared the flexural strength of different resins fabricated using different technologies (conventional, CAD-CAM-milled, and 3D-printed) and polymerization techniques. Methods: A total of 11 different resins were tested: six PMMA conventional (Acrypol R, Acrypol LL, Acrypol HI, Acrypol Fast, Acryself and Acryslef P), two milled obtained from UDMA PMMA disks (Ivotion disk and Aadva disk, control groups), two 3D-printed PMMA resins (NextDent Denture 3D+, and SprintRayEU Denture Base), and one 3D-printed composite resin (GC Temp Print). Flexural strength was measured using a universal testing machine. One-way ANOVA and Bonferroni post hoc tests were performed; the p-value was set at 0.05 to consider statistically significant differences among the groups. Spearman test was used to evaluate the correlation between polymerization technique and the flexural strength of 3D-printed resins. Results: CAD-CAM-milled specimens showed the highest flexural strength (107.87 MPa for UDMA) followed by 3D-printed composite resins (102.96 MPa). Furthermore, 3D-printed resins polymerized for 40 min with the BB cure unit showed no statistically significant differences with conventional resin groups. Moreover, in all the 3D-printed specimens, a high correlation between polymerization technique and flexural strength was found. Conclusions: In terms of flexural strength, the polymerization technique is a determinant for both acrylic and composite resins. Temp Print can be a potential alternative to fabricating removable dentures and showed promising results when used in combination with pink color resin powder
Influence of Printing Angulation on the Flexural Strength of 3D Printed Resins: An In Vitro Study
Get PDFFeatured Application: Flexural strength is a fundamental parameter for long-lasting restorations. Printing angulation affects the flexural strength differently depending on the 3D printed material. This study compared the flexural strength of various 3D printed resins fabricated at different building angles (0°, 45°, and 90°). Four groups of resins were tested: Varseo Smile Teeth (Bego GmbH & Co., Bremen, Germany), V-print C&B Temp (Voco GmbH, Cuxhaven, Germany), Bego Triniq (Bego GmbH & Co. KG, Bremen, Germany), and Sprintray Crown (SprintRay, Los Angeles, CA, USA). A digital light processing 3D printer (Asiga MAX UV, NSW, Sydney, Australia) was used to fabricate the samples at the specified build angles (0°, 45°, and 90°) in accordance with the ISO 4049:2019 standard. Flexural strength was measured using a universal testing machine (Instron 5567; Instron Ltd., Norwood, MA, USA), and fracture analysis was performed using a scanning electron microscope (Jeol JSM-6060LV, Tokyo, Japan). Statistical analysis was carried out using the Statistical Package for the Social Sciences (SPSS, version 26; IBM Corp., Chicago, IL, USA). Means and standard deviations were calculated for each group, and statistical differences were assessed using one-way ANOVA followed by the Bonferroni post hoc test (p < 0.05). All tested resins exhibited high flexural strength values. The maximum flexural strength was observed in the 0° printed samples (137.18 ± 18.92 MPa), while the lowest values were recorded for the 90° printed samples (116.75 ± 24.74 MPa). For V-print C&B Temp, the flexural strength at 90° (116.97 ± 34.87 MPa) was significantly lower compared to the 0° (156.56 ± 25.58 MPa) and 45° (130.46 ± 12.33 MPa) orientations. In contrast, Bego Triniq samples printed at 45° (148.91 ± 21.23 MPa) demonstrated significantly higher flexural strength than those printed at 0° (113.37 ± 31.93 MPa) or 90° (100.96 ± 16.66 MPa). Overall, the results indicate that the printing angle has a significant impact on the flexural strength of the materials, with some resins showing lower strength values at the 90° build angle
Comparison of physico-chemical properties of zinc oxide eugenol cement and a bioceramic sealer
No full textThe aim of the present study was to compare the physico-chemical properties of EssenSeal with AH PLUS bioceramic and Pulp Canal Sealer EWT. Flow, solubility, film thickness, radiopacity and setting time were evaluated according to ISO 6876 (2012) specifications. External and cross-section surface characteristics were analysed under a scanning electron microscope. Statistical analysis was performed using Shapiro–Wilk's test, one-way ANOVA and the Tukey HSD test. All the sealers conformed to the ISO 6876 (2012) standards, except for the setting time for AH plus bioceramic, which exceeded more than 10% of the time indicated by the manufacturer. Statistically significant differences were found between the three study sealers regarding the physico-chemical properties tested (p < 0.05). EssenSeal demonstrated characteristics respecting the ISO 6876 (2012) standards and can be considered a predictable alternative in root canal sealing
A Randomized Controlled Clinical Trial on Press, Block Lithium Disilicate, and 3D Printed Partial Crowns in Posterior Teeth: One-Year Recall
Get PDFThis study compares the clinical performances of two lithium disilicate (Initial LiSi press vs. Initial LiSi Block, GC Corp.) and a 3D printed resin (Temp Print, GC Corp.) partial crown using modified United States Public Health Service (USPHS) evaluation criteria and survival rates after one year of clinical service. Eighty-nine partial adhesive restorations on posterior teeth were realized using different materials: Group 1 used Initial LiSi press, Group 2 used Initial LiSi Block, and Group 3 used Temp Print. An analog workflow was used to realize the restoration of Group 1, while a fully digital workflow was used for Groups 2 and 3. The modified USPHS parameters, together with periodontal parameters, were collected at baseline and at the one-year recall. Contingency tables to assess for significant differences of success over time in each group were used. All modified USPHS parameters showed Alpha or Bravo; no Charlie was recorded. No statistically significant difference emerged between the three groups in any of the assessed variables (p > 0.05). All modified USPHS scores were compatible with the outcome of clinical success, no restoration was replaced or repaired, and the survival rate was 100% at the one-year recall. No difference was found between the traditional and digital workflows used to fabricate the restorations
Accuracy of Four Intra-Oral Scanners in Subgingival Vertical Preparation: An In Vitro 3-Dimensional Comparative Analysis
Get PDFOne of the most critical aspects in intraoral impression is the detection of the finish line, particularly in the case of subgingival preparations. The aim of this in vitro study was to evaluate the accuracy among four different Intra Oral Scanners (IOSs) in scanning a subgingival vertical margins preparation (VP). A reference maxillary typodont (MT) was fabricated with a VP for full crown on #16 and #21. The MT was scanned with a laboratory scanner (Aadva lab scanner, GC, Tokyo, Japan) to obtain a digital MT (dMT) in.stl format file. A group of 40 digital casts (dIOC) were obtained by scanning the MT 10 times with four different IOSs: Trios 3, 3Shape A/S; I700, Medit; Vivascan, Ivoclar; and Experimental IOS, GC. All the obtained dIOCs were imported into an inspection software program (Geomagic Control X; 3D SYSTEMS) to be superimposed to the dMT in order to calculate trueness. Therefore, in order to calculate precision, all the scans of the same scanner group were superimposed onto the cast that obtained the best result of trueness. The results were collected as the root mean square value (RMS) on the #16 and #21 abutment surfaces and on a marginal area positioned 1 mm above and below the gingival margin. A nonparametric analysis Kruskal–Wallis test was performed to compare the RMS values obtained in the different iOS groups for trueness and precision. Statistical significance was set at 0.05. For the trueness on the #16 abutment, the Vivascan reported statistically lower values, while on the #21 abutment, Vivascan (56.0 ± 12.1) and Experimental IOS, GC (59.2 ± 2.7) performed statistically better than the others. Regarding precision, Experimental IOS, GC were significantly better than the others on #16 (10.7 ± 2.1) and in the #21 area Experimental, GC, and Trios 3 performed statistically better(16.9 ± 13.8; 18.0 ± 2.7). At the subgingival marginal level for both #16 and #21, all the IOS reported reduced accuracy compared to clinical acceptance
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