scholarly journals Influence of two different cement space settings and three different cement types on the fit of polymer-infiltrated ceramic network material crowns manufactured using a complete digital workflow

2019 ◽  
Vol 24 (6) ◽  
pp. 1929-1938 ◽  
Author(s):  
Rinet Dauti ◽  
Bledar Lilaj ◽  
Patrick Heimel ◽  
Andreas Moritz ◽  
Andreas Schedle ◽  
...  

Abstract Objectives The study evaluates the influence of two spacer settings and three resin luting materials on the marginal and internal fit of polymer-infiltrated ceramic network (PICN) material crowns manufactured using a complete digital workflow. Methods Optical impressions of fifty identical dies were performed using the 3M scanner (software version 5.0.2). Twenty crowns were designed using Ceramill Mind (version 3.4.10.1163), from which ten with spacer setting of 50 μm (G1) and ten with 80 μm (G2). Thirty crowns (spacer setting of 50 μm) were divided into three groups corresponding to the resin materials used as follows: RelyX Unicem (RX), Variolink Esthetic (VLE), and Nexus 3 (NX3). All crowns were milled from Vita Enamic blocks. After micro-CT scanning, absolute marginal discrepancy (AMD), internal gap (IG), total cement space volume (TCV), and marginal porosities (VP) were measured. Results Significant difference was detected on the VP between the RX and NX3 group (p = 0.033). The mean values of all parameters were the following: AMD (μm): G1 182.6, G2 253.7, RX 210.8, VLE 195.5, NX3 186.6; IG (μm): G1 215.6, G2 173.1, RX 171.1, VLE 198.6, NX3 203; TCV (mm3): G1 22.9, G2 20.49, RX 17.57, VLE 17.49, NX3 20.59; VP (mm3): G1 0.26, G2 0.34, RX 0.32, VLE 0.46, NX3 0.54. Conclusions Fit of PICN material crowns was not significantly influenced by increasing the spacer settings and cementation with different resin materials. Additionally, RelyX Unicem showed significantly less porosities as compared with Nexus3. Clinical relevance Both 50 μm and 80 μm virtual spacer settings can be suggested for the manufacture of PICN crowns when Ceramill Mind (version 3.4.10.1163) is used. Furthermore, a self-adhesive system can be recommended for the cementation.

2004 ◽  
Vol 5 (2) ◽  
pp. 93-101 ◽  
Author(s):  
Oya Bala ◽  
L. Sibel Karadag ◽  
Emin Türköz ◽  
Tansev Mihçioğlu

Abstract In this study, the aim was to assess the in vitro apical microleakage of a resin-based sealer used with two different adhesives. Thirty nine freshly extracted maxillary incisors were used. The teeth were decoronated at the cemento-enamel junction with a water-cooled fissure bur. Chemo-mechanical debridement of the root canals was accomplished with the step-back technique. The smear layer was removed by 19% ethylenediamine tetra acetic acid (EDTA). The roots were then divided into three experimental groups of thirteen teeth in each. Specimens in group 1 were filled with gutta-percha, AH Plus sealer, and water-based adhesive system (Syntac Single Component). Group 2 specimens were filled with gutta-percha, AH Plus sealer, and acetone-based dentin adhesive (Prime & Bond NT). Specimens of group 3 were filled with only gutta-percha and AH Plus sealer (no adhesive was applied). The teeth were immersed into 2% methylene blue solution. Apical sealing qualities were assessed by measuring the linear dye penetration with a stereomicroscope. Dentin tubule penetration was observed under scanning electron microscopy (SEM). Results showed no statistically significant difference between the materials used, however, the leakage in group 2 was less than group 1 and 3. Citation Karadag LS, Bala O, Türköz E, Mihçioğlu T. The Effects of Water and Acetone-based Dentin Adhesives on Apical Microleakage. J Contemp Dent Pract 2004 May;(5)2:093-101.


2019 ◽  
Vol 18 ◽  
pp. e191603
Author(s):  
Camilla Lopes Cerqueira ◽  
Roniel Kappler ◽  
Andrea Araújo Nobrega Cavalcanti ◽  
Emilena Maria Castor Xisto Lima

Aim: To evaluate the marginal adaptation of provisional crowns made of acrylic and bisacrylic resins using different impression materials. Methods: a metal die and a matrix applied through a direct technique were used to fabricate the specimens. The impression materials used as a matrix were divided into four groups: Irreversible hydrocolloid
(IH), laboratory silicone (LS), condensation silicone (CS), and addition silicone (AS). After the impression procedures, each matrix was loaded with the provisional prosthetic materials, Alike, Duralay, Protemp 4, and Structur 3 (n = 12). Marginal discrepancy was evaluated using a stereomicroscope at ×45 magnification. The images obtained were transferred to the Corel Draw X7 program, and the distances from the cervical margins of the specimen to the reference lines at the metal die were measured vertically. The data were analyzed by using 2-way ANOVA followed by the Tukey test (α=.05). Results: the acrylic resins had higher values ​​of marginal discrepancy compared to the bisacrylic resins. A statistically significant difference was found between all impression materials, and the irreversible hydrocolloid presented higher values of discrepancy (303.28–613.31 μm), whereas addition silicone had the lowest (48.61–190.06 μm). Conclusions: the bisacrylic resins had a better marginal adaptation compared to the acrylic resins. The addition silicone promoted a better marginal adaptation of the provisional prosthetic materials tested, followed by condensation silicone, laboratory silicone, and irreversible hydrocolloid.


BDJ Open ◽  
2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Fatema Khaled Mansour ◽  
Rabab Mohammed Ibrahim ◽  
Hoda Mansour ◽  
Ahmed Mohamed Hamdy

Abstract Statement of problem Accuracy of internal fit and microleakage for CAD-CAM systems used in metal coping fabrication and veneered with layering or pressing porcelain in ceramometallic restoration is unclear. Material and methods A master metal die was milled to resemble the right mandibular first molar preparation for coverage with ceramometallic restoration. Master die was duplicated to twenty-four resin specimen dies.They were divided into two groups according to metal coping construction technique using either conventional (C) or CAD (D) wax. Each group was subdivided into two subgroups (n = 6) according to the technique of porcelain veneering (layered or pressed) to fabricate ceramometallic restorations, where subgroup (CL, DL) were conventionally layered by porcelain and (CP, DP) were press veneered. A standardized thickness of metal and porcelain was performed in all specimens as per manufacturer’s instructions for techniques ceramometallic restoration construction. Evaluation of internal fit was done with silicone replica technique using stereomicroscope at ×24 magnification where the thickness of silicon layer was measured at 20 reference points on each specimen. Then specimens were subjected to thermocycling. Sectioned specimens were assessed for microleakage using a stereomicroscope at ×12 magnification along die-cement interface with a five scale score. Results Mean internal gap values of veneering showed a statistically nonsignificant difference between specimens made with layering(L) and pressing(P). Different techniques of wax construction showed a non-significant difference in internal gap values between specimens made with conventional(C) and CAD(D) waxing. However, a significant difference was found in the internal gap at different sites. The highest internal gap was found at the occlusal surface, while the lowest gap was found at the finish line. The highest mean microleakage score was found with CAD wax and press veneering, while the lowest mean microleakage score was found with conventional wax and press veneering. Conclusion Both construction techniques of ceramometallic restoration were considered reliable in restoration production within a clinically acceptable range regarding internal fit and microleakage. There is a strong positive correlation between internal fit and microleakage of ceramometallic restoration constructed.


2021 ◽  
Vol 21 ◽  
pp. e225136
Author(s):  
Patrícia Valéria Manozzo Kunz ◽  
Gabriela Andrade Serpa ◽  
Leonardo Fernandes da Cunha ◽  
Gisele Maria Correr ◽  
Carla Castiglia Gonzaga

Aim: To evaluate the influence of cobalt-chromium (Co-Cr) coping fabrication methods and ceramic application on the marginal and internal fit of metal-ceramic crowns. Methods: Co-Cr copings for metal-ceramic crowns were prepared by lost wax casting or CAD-CAM machining of sintered blocks. The fit was analyzed using the silicone replica technique at four assessment points: marginal gap (MG), axial wall (AW), axio-occlusal (AO) angle, and central occlusal (CO) wall. After the initial analysis, the copings were ceramic-veneered with the layering technique, and the fit was again determined. Data were statistically analyzed by paired and unpaired Student’s-t test (α=0.05). Results: Marginal and internal fit before ceramic application according to the coping manufacturing method showed significant differences only at CO (p < 0.001), with milled copings (137.98±16.71 μm) showing higher gap values than cast copings (112.86±8.57 μm). For cast copings, there were significant differences at MG (before 109.13±8.79 μm; after 102.78±7.18 μm) and CO (before 112.86±8.57 μm; after 104.07±10.63 μm) when comparing the fit before and after ceramic firing. For milled copings, there was significant difference only at AO (before 116.39±9.64 μm; after 108.54±9.26 μm). Conclusion: This study demonstrated that the coping fabrication method influenced the internal fit. Ceramic firing maintained or improved the fit of the metal-ceramic crowns. The marginal discrepancy of all restorations, before and after ceramic firing, can be considered clinically acceptable.


2012 ◽  
Vol 23 (4) ◽  
pp. 417-421 ◽  
Author(s):  
Ricardo Danil Guiraldo ◽  
Thaís Teixeira Borsato ◽  
Sandrine Bittencourt Berger ◽  
Murilo Baena Lopes ◽  
Alcides Gonini-Jr ◽  
...  

This study compared the surface detail reproduction and dimensional accuracy of stone models obtained from molds disinfected with 2% sodium hypochlorite, 2% chlorhexidine digluconate or 0.2% peracetic acid to models produced using molds which were not disinfected, with 3 alginate materials (Cavex ColorChange, Hydrogum 5 and Jeltrate Plus). The molds were prepared over matrix containing 20-, 50-, and 75-µm lines, performed under pressure with perforated metal tray. The molds were removed following gelation and either disinfected (using one of the solutions by spraying followed by storage in closed jars for 15 min) or not disinfected. The samples were divided into 12 groups (n=5). Molds were filled with dental gypsum Durone IV and 1 h after the start of the stone mixing the models were separated from the tray. Surface detail reproduction and dimensional accuracy were evaluated using optical microscopy on the 50-µm line with 25 mm in length, in accordance with the ISO 1563 standard. The dimensional accuracy results (%) were subjected to ANOVA. The 50 µm-line was completely reproduced by all alginate impression materials regardless of the disinfection procedure. There was no statistically significant difference in the mean values of dimensional accuracy in combinations between disinfectant procedure and alginate impression material (p=0.2130) or for independent factors. The disinfectant solutions and alginate materials used in this study are no factors of choice regarding the surface detail reproduction and dimensional accuracy of stone models.


Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 740
Author(s):  
Jie Wu ◽  
Hongjun Xie ◽  
Alireza Sadr ◽  
Kwok-Hung Chung

Different techniques have been used to construct provisional crowns to protect prepared teeth. The purpose of this in vitro study was to assess the internal fit and marginal discrepancy of provisional crowns made by different methods. A total of 48 provisional crowns were constructed and divided into three groups (n = 16) according to the fabrication methods: fabricated manually-group MAN; computer-aided design/computer aided manufacturing technology-group CAM; and 3-dimensional (3D)-printed technology-group 3DP. The same standard tessellation language (STL) file was used for both CAD/CAM and 3D-printed group. The silicone-checked method was used to measure the internal gap distance. The marginal discrepancy was measured by using the polyvinyl siloxane (PVS) replica method and swept-source optical coherence tomography (OCT) scanning technique. Data were analyzed with one-way analysis of variance (ANOVA) nonparametric Kruskal-Wallis and Tukey tests at α = 0.05. At the central pit and axial walls, the gap distance mean values of group CAM were higher than those from group MAN and 3DP. The group 3DP was statistically significantly higher in gap distance at the location of occlusion than group MAN and group CAM (p < 0.05). The total gap distances assessed by silicone-checked method revealed there were no statistically significant differences between the tested groups (p > 0.05). The total mean values of absolute and horizontal marginal discrepancy of the group 3DP obtained by using the PVS-replica method and OCT scanning technique were significantly higher than the group MAN and CAM (p < 0.05). Regression correlation results of marginal discrepancy indicated a positive correlation (r = 0.902) between PVS-replica method and OCT scanning technique. The manually fabricated provisional crowns presented better internal fit and a smaller marginal discrepancy. Between different assessment techniques for marginal adaptation, PVS-replica method and OCT scanning technique have a positive correlation.


1966 ◽  
Vol 53 (2) ◽  
pp. 177-188 ◽  
Author(s):  
P. Lund-Johansen ◽  
T. Thorsen ◽  
K. F. Støa

ABSTRACT A comparison has been made between (A), a relatively simple method for the measurement of aldosterone secretion rate, based on paper chromatography and direct densitometry of the aldosterone spot and (B) a more elaborate isotope derivative method. The mean secretion rate in 9 normal subjects was 112 ± 26 μg per 24 hours (method A) and 135 ± 35 μg per 24 hours (method B). The »secretion rate« in one adrenalectomized subject after the intravenous injection of 250 μg of aldosterone was 230 μg per 24 hours (method A) and 294 μg per 24 hours (method B). There was no significant difference in the mean values, and correlation between the two methods was good (r = 0.80). It is concluded that the densitometric method is suitable for clinical purposes as well as research, being more rapid and less expensive than the isotope derivative method. Method A also measures the urinary excretion of the aldosterone 3-oxo-conjugate, which is of interest in many pathological conditions. The densitometric method is obviously the less sensitive and a prerequisite for its use is an aldosterone secretion of 20—30 μg per 24 hours. Lower values are, however, rare in adults.


Author(s):  
Marcela Moreira Salles ◽  
Viviane de Cássia Oliveira ◽  
Ana Paula Macedo ◽  
Claudia Helena Silva-Lovato ◽  
Helena de Freitas Oliveira Paranhos

Implant-supported prostheses hygiene and peri-implant tissues health are considered to be predictive factors for successful prosthetic rehabilitation. Therefore, the purpose of this study was to evaluate the effectiveness of brushing associated with oral irrigation measured as biofilm-removing capacity, maintenance of healthy oral tissues, and patient satisfaction. A randomized, crossover clinical trial was conducted with 38 patients who wore conventional maxillary complete dentures and mandibular overdentures retained by the O-ring system. The patients were instructed to use the following hygiene methods for 14 days: mechanical brushing [MB (brush and dentifrice - Control)]; and MB with oral irrigation [WP (Waterpik - Experimental)]. Biofilm-removing capacity and maintenance of healthy oral tissues were evaluated by the Modified Plaque Index (PI), Gingival Index (GI), Probing Depth (PD), and Bleeding on Probing Index (BP) recorded at baseline and after each method. In parallel, patients answered a specific questionnaire using a Visual Analogue Scale after each hygiene method. Data were analyzed by Friedman and Wilcoxon tests (α=0.05). The results showed significantly lower PI, GI, PD, and BP indices after application of the hygiene methods (P&lt;0.001) than those observed at baseline. However, no significant difference was found between MB and WP. The satisfaction questionnaire responses to both methods showed high mean values for all questions, with no statistically significant difference found between the answers given after the use of MB and WP (P&gt;0.05). The findings suggest that WP was effective in reducing PI, GI, PD, and BP indices and provided a high level of patient satisfaction.


2017 ◽  
Vol 13 (1) ◽  
Author(s):  
Izabel Aparecida Soares ◽  
Mauro Sérgio Téo ◽  
Carlise DEBASTIANI ◽  
Suzymeire BARONI ◽  
Vanessa Silva RETUCI

O trabalho teve por objetivo verificar diferenças entre rendimento do concentrado proteico e proteína bruta da folha da mandioca (Manihot esculenta Crantz), obtidos a partir de três variedades comerciais: branca, cascuda e vermelha. As manivas foram plantadas seguindo o delineamento experimental inteiramente casualizado com três repetições. Nas comparações entre as variedades, considerou coletas escalonadas pós-plantio, realizadas aos 12, 14 e 16 meses. O concentrado proteico foi obtido a partir da farinha das folhas inteiras e submetido ao método de termo - coagulação ácido e a proteína bruta pelo método padrão AOAC. Os dados foram submetidos a análise de variância e comparados pelo teste de Tukey - 5% de probabilidade. Os resultados não indicaram diferença significativa entre as médias obtidas para rendimento de concentrado proteico. Para a variável porcentagem de proteína bruta a variedade Branca foi a que apresentou maior valor, com média de 46,25%, seguida pela Cascuda e Vermelha, 44,52% e 37,30%, sucessivamente. Conclui-se que outros estudos devem avaliar condições que possam influenciar no teor de proteína foliar, como clima e solo, e, avaliar os níveis de ácido cianídrico de cada variedade, indicando qual das três é a melhor para a extração do concentrado proteico das folhas. Palavras chaves: Manihot esculenta Crantz, variedades comerciais, concentrado proteico, proteína bruta. ABSTRACT: The study aimed to assess the differences between income protein concentrate, crude protein of cassava leaf (Manihot esculenta Crantz), obtained from three commercial varieties: white, red and cascuda. The cuttings were planted following the completely randomized design with three replications. Comparisons between the varieties considered after planting staggered collections, held on 12, 14 and 16 months. The protein concentrate was obtained from flour of whole sheets and subjected to the term method - acid coagulation and crude protein by AOAC standard method. The data were submitted to ANOVA and Tukey test - 5% probability. The results indicated no significant difference between the mean values obtained for protein concentrate income. For the variable percentage of crude protein White variety showed the highest, with an average of 46.25%, followed by cascuda and Red, 44.52% and 37.30%, successively. We conclude that further studies should evaluate conditions that may affect the leaf protein content, such as climate and soil, and evaluate the hydrocyanic acid levels of each variety, indicating which of the three is the best for the extraction of protein concentrate from leaves Key words: Manihot esculenta Crantz, commercial varieties, protein concentrate, crude protein.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1078.1-1079
Author(s):  
I. Yoshii

Background:Patient’s global assessment (PGA) is one important component of Boolean composite criteria for remission in treat with rheumatoid arthritis (RA). However, PGA no more than 10mm is sometimes obstacle to attain clinical remission. In recent few years, one opinion that PGA no more than 20mm may be comparable as no more than 10mm.Objectives:The aim of this study is to analyze how difference of these PGA level affect disease activity and daily activities in living, and evaluate which is optimal for the remission with Boolean remission criteria from real world setting.Methods:RA patients who were followed up for more than three years in the institute were picked up in the study. Each patient was monitored with tenderness joint count (TJC), swollen joint count (SJC), PGA, evaluator’s global assessment (EGA), serum C-reactive protein level (CRP), calculated disease activity score with simplified disease activity index(SDAI), Health Assessment Questionnaire Disability Index (HAQ-DI), and pain score using visual analog scale (PS-VAS) every consulted time from the first encounter (Baseline). Patients were classified according to achievement of Boolean remission criteria. Group 1: a patient group who attained Boolean remission wih TJC≦1, SJC≦1, CRP≦1mg/dl, and PGA≦1 (G-1), Group 2: a patient group who could not attained the Boolean remission used in the G-1 evaluation, but could attained another Boolean remission with TJC≦1, SJC≦1, CRP≦1mg/dl, and PGA≦2 (G-2), and Group 3: a patient group who could not attain Boolean remission for neither criterion.Mean values of measured parameters at Baseline and after the Baseline were compared statistically with Student T-test. Mean values of the same parameters in the G-1 and G-2 at the time of attain Boolean remission for each criteria, mean values of each of these parameters thereafter, and changes of these parameters were compared statistically with Student T-test.Results:A total of 438 patients 385 in the G-1 group, 16 in the G-2 group, and 37 in the G-3 group, were recruited. In parameters at Baseline, level of TJC, SJC, PGA, EGA, SDAI, and HAQ-DI in the G-1 was significantly lower than in the G-3, whereas no significant differences in any parameters demonstrated between in the G-2 and G-3. Level of HAQ-DI, and PS-VAS after Baseline in the G-1 was lower than in the G-3, whereas no significant difference of these parameters after Baseline demonstrated between in the G-2 and G-3. TJC, SJC, PGA, and EGA demonstrated significant less level in the G-1 than in the other two groups. The mean SDAI score at the time of first achievement of Boolean remission in the G-1 and G-2 were 1.08 and 2.57, respectively. The mean value of SDAI score after remission in the G-1 and G-2 were 3.35 and 6.44, respectively. These values and PS-VAS including change of the SDAI score demonstrated significant difference between the two groups (p<0.01), whereas HAQ-DI in the two groups demonstrated no significant difference.Conclusion:These results suggested that setting PGA as no more than 10mm should be reasonable for the evaluation of clinical remission with the Boolean criteria.Disclosure of Interests:None declared


Sign in / Sign up

Export Citation Format

Share Document