scholarly journals An In-Vitro Evaluation of Articulation Accuracy for Digitally Milled Models vs. Conventional Gypsum Casts

2022 ◽  
Vol 10 (1) ◽  
pp. 11
Author(s):  
Jason D. Lee ◽  
German O. Gallucci ◽  
Sang J. Lee
Keyword(s):  
Contact Region ◽  
In Vitro Study ◽  
Digital Workflow ◽  
Scanning Procedure ◽  
Digital Impressions ◽  
Significant Difference ◽  
Articulated Models ◽  
Scan Data ◽  
Group B

With the advent of a digital workflow in dentistry, the inter-occlusal articulation of digital models is now possible through various means. The Cadent iTero intraoral scanner uses a buccal scan in maximum intercuspation to record the maxillomandibular relationship. This in-vitro study compares the occlusion derived from conventionally articulated stone casts versus that of digitally articulated quadrant milled models. Thirty sets of stone casts poured from full arch polyvinyl siloxane impressions (Group A) and thirty sets of polyurethane quadrant models milled from digital impressions (Group B) were used for this study. The full arch stone casts were hand-articulated and mounted on semi-adjustable articulators, while the digitally derived models were pre-mounted from the milling center based on the data obtained from the buccal scanning procedure. A T-scan sensor was used to obtain a bite registration from each set of models in both groups. The T-scan data derived from groups A and B were compared to that from the master model to evaluate the reproducibility of the occlusion in the two groups. A statistically significant difference of the contact region surface area was found on #11 of the digitally articulated models compared to the master. An analysis of the force distribution also showed a tendency for a heavier distribution on the more anterior #11 tooth for the digitally articulated models. Within the limitations of this study, the use of a digitally articulated quadrant model system may result in a loss of accuracy, in terms of occlusion, the further anteriorly the tooth to be restored is located. Care must be taken to consider the sources of inaccuracies in the digital workflow to minimize them for a more efficient and effective restorative process.

Comparative Study to Evaluate the Surface Detail Reproduction of Dental Stone after Immersion in Various Different Disinfectant Solutions, Under Stereomicroscope 10 X Magnification –An In-Vitro Study

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
Rathika Rai ◽  
M. A. Easwaran ◽  
K. T. Dhivya
Keyword(s):  
Sodium Hypochlorite ◽  
In Vitro Study ◽  
Control Group ◽  
Immersion Method ◽  
Significant Difference ◽  
Surface Irregularities ◽  
Disinfectant Solution ◽  
Surface Detail ◽  
Group B

Aim: To evaluate the surface detail reproduction of dental stone this is immersed in different disinfectant solution and studied under stereomicroscope. Methodology: Total number of 30 specimens of dental stone (Type III) were made with measurements of 1.5cm diameter and 1cm height .This samples are divided in to 3 groups group A,B,C. were A is immersed in Distilled water which was taken as control group ;B is immersed in 2% Glutaraldehyde and C is immersed in 5%sodium hypochlorite. Each specimen were immersed in the disinfectant solution for 15 minutes and dried under room temperature for 24 hrs. After 24 hrs each specimens are studied under stereomicroscope for surface details. Result: The results showed no significant difference in the surface irregularities and porosities for a group 1 and group 2 except group 3 which showed significant increase in the porosities, surface irregularities and erosions after disinfection with 5% NaHOCl by immersion method. Conclusion: The surface detail reproduction capacity of die stone was adversely affected when 5% Sodium hypochlorite was used as disinfectant solution when compare d to control group and 2% Glutaraldehyde

scholarly journals To Evaluate the Marginal Fit of Metal Copings Fabricated by Conventional Casting Procedure and Direct Metal Laser Sintering Technology – an In Vitro Study

2017 ◽  
Vol 05 (01) ◽  
pp. 039-046 ◽  
Author(s):  
Monica Sharma ◽  
Ajay Bansal ◽  
Sunny Panthi ◽  
Shefali Malik ◽  
Atulya Sharma
Keyword(s):  
Glass Ionomer Cement ◽  
In Vitro Study ◽  
Laser Sintering ◽  
Vitro Study ◽  
Direct Metal Laser Sintering ◽  
Marginal Fit ◽  
Significant Difference ◽  
Group A ◽  
Group B

Abstract Purpose: The purpose of this in vitro study was to evaluate marginal fit of cobalt- chromium (Co-Cr) copings fabricated by direct metal laser sintering system (DMLS) and conventional lost-wax technique (LW). Materials and method: Forty tooth preparations were carried out over extracted mandibular molars. They were divided into two groups A and B of 20 each. For group A Co-Cr copings were fabricated by direct metal laser sintering (DMLS) and for group B by lost wax technique (LW). Glass –ionomer cement (GIC) was used to tack the copings over their preparations. Marginal fit was then evaluated directly under the stereomicroscope. Results: The mean marginal gap of group A was 27.9 ± 2.4 μm and group B was 40.4 ±6 μm. Statistical analysis using t - test showed highly significant difference (P>.05) between the marginal mean of the DMLS (group A) compared to LW (group B). Conclusion: The DMLS copings demonstrated superior marginal fit compared to that of conventional Co-Cr casted copings.

scholarly journals Evaluation of the Effect of Water on Three Different Light Cured Composite Restorative Materials Stored in Water: An In Vitro Study

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Basawaraj Biradar ◽  
Sudharani Biradar ◽  
Arvind MS
Keyword(s):  
Water Absorption ◽  
Physical And Mechanical Properties ◽  
In Vitro Study ◽  
Vitro Study ◽  
Weight Changes ◽  
Significant Difference ◽  
Restorative Materials ◽  
Group A ◽  
Group B

Objectives. The objective of this in vitro study was to investigate whether weight gain or loss in the three different composites occurs due to water absorption when they are stored in water.Methods. The composite restorative materials selected for this study included a microfine hybrid (Synergy) and two nanofilled composite restorative materials (Ceram X and Filtek Supreme Ultra). Twenty specimens of each material were fabricated of each composite material. Group A: Filtek Supreme Ultra, Group B: Synergy, Group C: Ceram X. Then all the specimens were stored in 10 ml Distilled water containing test tubes and placed in incubator at 37°C for six weeks. The weight changes of these specimens were measured daily for the first week and later once a week for next five weeks by using an electrical analytical balance.Results.The data was analyzed by one-way analysis of variance and Student'sttest. All groups showed maximum amount of water absorption in the first week than gradual decrease in the water absorption from the second to the sixth week, as compared to the first week and there is no statistically significant difference between the groups tested.Conclusion. All the composite restorative material absorbs some amount of water. The water absorption of the composite may decrease the physical and mechanical properties of the composites; hence it is necessary to consider the type of the material before starting the treatment.

Influence of prophylaxis on the microleakage of sealants: in vitro study

2002 ◽  
Vol 26 (4) ◽  
pp. 371-375 ◽  
Author(s):  
Ana Beatriz Alonso Chevitarese ◽  
Orlando Chevitarese ◽  
Ivete Pomarico Ribeiro de Souza ◽  
Roberto Braga de Carvalho Vianna
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
In Vitro Study ◽  
Optical Microscope ◽  
Vitro Study ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
Scanning Electron

The aim of this study was to evaluate the influence of prophylaxis on the sealants microleakage in 30 premolars divided into: Group A, Group B and Group C. The teeth were analyzed using the optical microscope (OM) and at scanning electron microscope (SEM). There was a statitical significant difference among the groups regarding the presence of microleakage, but not with the presence of tags.

scholarly journals Assessment of Exogenous Pigmentation on Clear Elastomeric Modules: An in vitro Study

2018 ◽  
Vol 8 (1) ◽  
pp. 33-36
Author(s):  
Shaista N Ansari ◽  
Dhananjay Rathod ◽  
G P Rathod ◽  
Gazal Bisht
Keyword(s):  
Methylene Blue ◽  
In Vitro Study ◽  
Vitro Study ◽  
Orthodontic Appliances ◽  
Significant Difference ◽  
Adobe Photoshop ◽  
Group A ◽  
Strong Staining ◽  
Group B

Objective: To assess in vitro changes in the shade of clear elastomeric modules from different manufacturers influenced by exogeneous pigmentation contained in everyday dietary substances.Materials & Method: The specimen comprised of clear elastomeric modules (Group A: Libral, Group B: TP Orthodontics) which were immersed in dietary substances: ketchup, coffee, tea, pepsi & methylene blue. Their hue, saturation and intensity were figured after 72 hours by methods of Adobe photoshop CS3 to mirror the module recoloring seriousness.Result: Significant difference was found between two types of modules analyzed in this study. Ketchup and methylene blue demonstrated higher staining potential compared to other staining media. Besides, there was no significant difference in staining contrast between tea and Pepsi.Conclusion: Ketchup and methylene blue are strong staining media, ought to be avoided by the patients opting for aesthetic orthodontic appliances. Elastomeric modules manufactured by different companies have differing staining potential. 

The Effect of Varying Ferrule Modes on Fracture Resistance of Canines Restored with One-Piece Milled Zirconia Post and Core

2012 ◽  
Vol 624 ◽  
pp. 98-102
Author(s):  
Yao Kun Zhang ◽  
Long Quan Shao ◽  
Ruo Yu Liu ◽  
Lin Lin Wang ◽  
Jun Ai ◽  
...  
Keyword(s):  
Fracture Resistance ◽  
In Vitro Study ◽  
Significant Difference ◽  
Zirconia Crowns ◽  
Group A ◽  
Post And Core ◽  
Resistance Decrease ◽  
Group B ◽  
Group D

The aim of this invitro study was to evaluate the fracture resistance of endodontically treated canines restored with one-piece milled zirconia post and core in the varying ferrule modes. Fifty recently extracted human maxillary canines were endodontically treated and randomly divided into 5 groups of 10 specimens each. According to the defect degree of ferrule, intact ferrule was classified as group A and served as control, 2 mm ferrule height without buccal ferrule was classified as group B, 2 mm ferrule height without mesial and buccal ferrule was classified as group C, 2 mm ferrule height without mesial, buccal and lingual ferrule was classified as group D, no ferrule preparation was classified as group E. All of the teeth were restored with one-piece milled zirconia post and core, and zirconia crowns. The teeth were prepared to standardized specifications. The restored teeth were loaded to fracture at a 135° angle to their long axis, at a cross-head speed 0.5 mm/min, and the load (N) at failure was recorded. Statistical analysis was performed by SNK pairwise multiple comparisons (α=0.05). The mean fracture resistance of five groups as follows: 1019.30±139.01N for group A, 861.20±105.67N for group B, 833.70±100.56N for group C, 733.20±96.91N for group D, 698.00±99.90N for group E. The fracture resistance of restored teeth between group B and group C, group D and group E had no statistically significant difference(P>0.05). The fracture resistance of the rest pairwise group comparisons had statistically significant difference(P<0.05). Increasing the absence degree of ferrule, it was found that the fracture resistance decrease. The buccal and lingual ferrule were more important than mesial ferrule for enhanced fracture resistance. This in vitro study supports evidence that reserving the buccal and lingual ferrule is a key point to increase the fracture resistance of canines restored with one-piece milled zirconia post and core.

scholarly journals Fracture Strength of Monolithic Zirconia Crowns with Modified Vertical Preparation: A Comparative In Vitro Study

2021 ◽  
Author(s):  
Marwah Ismael Abdulazeez ◽  
Manhal A. Majeed
Keyword(s):  
Fracture Strength ◽  
In Vitro Study ◽  
Fracture Load ◽  
Significant Difference ◽  
Zirconia Crowns ◽  
Group A ◽  
Monolithic Zirconia ◽  
Bonferroni Test ◽  
Group B

Abstract Objective The aim of this study was to evaluate the influence of different marginal designs (deep chamfer, vertical, and modified vertical with reverse shoulder) on the fracture strength and failure modes of monolithic zirconia crowns. Materials and Methods Thirty sound human maxillary first premolar teeth with comparable size were used in this study. The teeth were divided randomly into three groups according to the preparation design (n = 10): (1) group A: teeth prepared with a deep chamfer finish line; (2) group B: teeth prepared with vertical preparation; and (3) group C: teeth prepared with modified vertical preparation, where a reverse shoulder of 1 mm was placed on the buccal surface at the junction of middle and occlusal thirds. All samples were scanned by using an intraoral scanner (CEREC Omnicam, Sirona, Germany), and then the crowns were designed by using Sirona InLab 20.0 software and milled with a 5-axis machine. Each crown was then cemented on its respective tooth with self-adhesive resin cement by using a custom-made cementation device. A single load to failure test was used to assess the fracture load of each crown by using a computerized universal testing machine that automatically recorded the fracture load of each sample in Newton (N). Statistical Analysis The data were analyzed statistically by using one-way analysis of variance test and Bonferroni test at a level of significance of 0.05. Results The highest mean of fracture load was recorded by chamfer (2,969.8 N), which followed by modified vertical (2,899.3 N) and the lowest mean of fracture load was recorded by vertical (2,717.9 N). One-way ANOVA test revealed a significant difference among the three groups. Bonferroni test showed a significant difference between group A and group B, while a nonsignificant difference was revealed between group C with group A and group B. Conclusion Within the limitations of this in vitro study, the mean values of fracture strength of monolithic zirconia crowns of all groups were higher than the maximum occlusal forces in the premolar region. The modification of the vertical preparation with a reverse shoulder placed at the buccal surface improved the fracture strength up to the point that it was statistically nonsignificant with the chamfer group.

scholarly journals Assessing Fracture Resistance of Restored Premolars with Novel Composite Materials: An In Vitro Study

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Zahraa Abdulaali Al-Ibraheemi ◽  
Huda Abbas Abdullah ◽  
Nada Abdlameer Jawad ◽  
Julfikar Haider
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
In Vitro Study ◽  
Vitro Study ◽  
Resistance Testing ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
Group D

During restorative treatment, premolars restored with resin filling materials using the conventional incremental-fill technique take longer restoration time and undermine the integrity of the tooth. The aim of this study was to assess fracture resistance of premolars restored by various types of novel bulk-fill composite resin materials. Forty-eight (n = 48) freshly extracted sound maxillary first premolars were used in this in vitro study. The teeth were divided into six groups, each having 8 specimens. Group A (positive control) was allocated for the intact teeth. For specimens in Groups B to F, a large cavity (Class-II MOD) was prepared with a standardized dimension of cavity (3 mm depth on the pulpal floor, 4 mm at the gingival seat, and 3 mm cavity width). Group B represented prepared teeth without any restoration. Group C, Group D, Group E, and Group F were restored with Tetric EvoCeram® incremental-fill (conventional), Beautifil bulk-fill, Filtek posterior bulk-fill, and SonicFill 2 bulk-fill restorative materials, respectively. All samples were finished and polished with an enhanced finishing kit and stored in distilled water for a month before the fracture resistance testing. All the samples were exposed to the axial loading (the speed of crosshead was 1 mm/min) in a computer-controlled universal testing machine (LARYEE, China) via a steel bar (6 mm in diameter) and the maximum applied force in Newton was recorded as the fracture resistance. One-way analysis of variance (SPSS 21) was used to compare the fracture resistance within the groups, and Tukey’s post hoc test was used to determine the difference between the groups. The lowest value of fracture resistance was recorded for Group B, and the highest value was recorded for Group A followed by the values of Group D, Group C, Group F, and Group E. One-way ANOVA revealed a statistically significant difference between the groups ( P < 0.05 ). Nonsignificant difference was found between the premolars restored by bulk-fill and conventional composites. Among the bulk-fill restored specimens, Beautifil restorative demonstrated significantly higher fracture resistance in comparison with the other two bulk-fill restored specimen groups (SonicFill 2 and Filtek). Bulk-fill composite such as Beautifil could be an alternative option to conventional incremental-fill composite for premolar restoration.

Sealing Ability of ProRoot MTA and MTA-Angelus Simulating a One-Step Apical Barrier Technique- An in vitro Study

2009 ◽  
Vol 33 (4) ◽  
pp. 305-310 ◽  
Author(s):  
Nikita Lolayekar ◽  
Sham Bhat ◽  
Sundeep Hegde
Keyword(s):  
Calcium Hydroxide ◽  
In Vitro Study ◽  
Control Group ◽  
Blue Dye ◽  
Root Segments ◽  
Sealing Ability ◽  
Significant Difference ◽  
Group A ◽  
Group B

Endodontic treatment of the pulpless tooth with an immature root apex poses a special challenge for the clinician due to lack of an apical stop against which to compact an interim dressing of calcium hydroxide, or the final obturation material. A one-visit apexification protocol with MTA (Mineral Trioxide Aggregate) has be seen as an alternative to the traditional treatment practices with calcium hydroxide [Ca(OH)2]. The aim of this study was to investigate the use of MTA as a 5mm apical barrier by comparing sealing ability of ProRoot MTA to that of MTA-Angelus. 50 freshly extracted Maxillary and Mandibular single canal sound human incisor teeth were used in this study, which were decoronated to standardized 10mm root lengths. The root segments were prepared to simulate the clinical situation of an open apex with Gates Glidden burs # 5-1 and randomly assigned into 2 experimental groups of 20 samples each (Group A: ProRoot MTA, Group B: MTA-Angelus) and 10 root segments were used as control (Group C) where no apical barrier was used. After obturation the coronal portion of all samples were sealed with Glass Ionomer and stored at 37°C and 100% humidity for 4 weeks. The root segments were then double coated with nail varnish except for the apical 1mm and apical ends of all root segments were suspended vertically in methylene blue dye for 48 hours at room temperature. After removal from the dye, the samples were sectioned longitudinally and linear dye penetration was measured using a Grid and stereomicroscope. The measurements were tabulated and statistically analyzed. The mean percentage of dye leakage for Group A was 55.5% and for Group B was 53.25%. The results showed no statistically significant difference in the sealing ability of ProRoot MTA and MTA-Angelus when used as apical barriers.

scholarly journals Evaluation of Film Thickness of Crown Disclosing Agents and Their Comparison with Cement Film Thickness after Final Cementation

2020 ◽  
Vol 14 (02) ◽  
pp. 224-232
Author(s):  
Syed Rashid Habib ◽  
Abdul Sadekh Ansari ◽  
Salwa Omar Bajunaid ◽  
Abdullah Alshahrani ◽  
Muhammad Qasim Javed
Keyword(s):  
Statistical Analysis ◽  
Film Thickness ◽  
In Vitro Study ◽  
Test Material ◽  
Finish Line ◽  
Significant Difference ◽  
Digital Microscope ◽  
Group A ◽  
Group B

Abstract Objective Verification of the accuracy of crown fit before final cementation is imperative. The aim of this in vitro study was to evaluate the film thickness of commonly used dental crown disclosing materials and their comparison with final cement thickness. Materials and Methods One hundred fifty provisional crowns (Protemp) were fabricated on standardized resin dies and divided into five groups (N = 150; n = 30) based on five disclosing agents: A = Fit-Checker auto-mix; B = Okklu-top; C = Express; D = Fit-Checker hand-mix; E = Coltene PSI, and Final cement = Relyx U200. Crowns were loaded with test materials, tried over dies under load (50N), and later cemented under same load. Film thickness (µm) was recorded between crown margin and the finish line of die after loading with test material and final cementation using a digital microscope. Statistical Analysis Descriptive statistics, analysis of variance, Tukey’s and paired t-test were used for statistical analysis (p < 0.05). Results Significant variations were found between the film thicknesses of the five disclosing agents (p = 0.019). Group-A showed the lowest (131.67 ± 101.10 μm), while group-B (295.00 ± 263.88 μm) showed the highest film thickness (p = 0.011). Film thicknesses after cementation were similar for groups (p = 0.957). Significant difference was observed for group-B disclosing agent versus final cement (p = 0.010). The lowest mean difference between the film thicknesses of the disclosing agent and final cementation of 13.1 μm was revealed for group-A. Conclusions Variations in the film thicknesses of the tested disclosing agents were found. Fit-Checker auto-mix was found with minimal film thickness and satisfied the requirements as the disclosing agent, while Okklu-top aerosol spray did not.

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