scholarly journals Accuracy of Different Head Movements of Intraoral Scanner in Full Arch of Both Maxilla and Mandible

2021 ◽  
Vol 11 (17) ◽  
pp. 8140
Author(s):  
Chun-Wei Feng ◽  
Chun-Cheng Hung ◽  
Jen-Chyan Wang ◽  
Ting-Hsun Lan
Keyword(s):  
In Vitro Study ◽  
Head Movements ◽  
Intraoral Scanner ◽  
Second Molar ◽  
Scan Path ◽  
Linear Movement ◽  
Optical Impression ◽  
Maxilla And Mandible ◽  
Post Hoc

This in vitro study aimed to compare the accuracy of maxilla and mandible full-arch scans from an intraoral scanner via one scan path with six different head movements. Standard maxilla and mandible models via holder were set in a dental chair to simulate position and posture. The reference models’ standard tessellation language (STL) files were formatted via desktop scanner, and operative models’ files were obtained via IOS TRIOS 3 Pod as superimposed by Exocad CAD software. The same scan path with six head movements (Linear, Circle, Wave, 8-figure, S-figure, and A-P) were designed to scan 10 times per jaw, and a total of 120 scan files were then compared with reference files. The data were recorded and deviations of both occlusal and B-L sides were compared, with statistical analysis being performed by one-way analysis of variance (ANOVA) and post hoc comparisons with Tukey test. The trueness of optical impression for full-arch via one path with six head movements differed from maxilla and mandible and depended on the different movements (p < 0.05). In the same path, peak deviation was found at the turning points for left central incisor, left first premolar, left second molar, and right second molar in maxilla, and for right first premolar, second molar, and left second molar in the mandible. The 8-figure movement showed the highest deviation (0.128 ± 0.086 mm) in the maxilla and (0.105 ± 0.069 mm) in the mandible. The Linear movement presented the lowest deviation (0.096 ± 0.07 mm) in the maxilla while the Circle movement presented the lowest deviation (0.073 ± 0.041 mm) in the mandible, with the 8-figure movement showing the worst precision among six movements. In the maxilla, the S- and 8-figure movements were not recommended, while the Linear and Circle movements showed high trueness. In the mandible, the 8-figure movement was not recommended, while the other five presented similar lower deviations.

scholarly journals Effect of Tooth Types on the Accuracy of Dental 3D Scanners: An In Vitro Study

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1744 ◽  
Author(s):  
Keunbada Son ◽  
Kyu-bok Lee
Keyword(s):  
Computer Aided Design ◽  
Reference Model ◽  
Three Dimensional ◽  
In Vitro Study ◽  
Test Model ◽  
Intraoral Scanner ◽  
3D Scanners ◽  
Aided Design ◽  
Post Hoc

The purpose of this study was to evaluate the accuracy of dental three-dimensional (3D) scanners according to the types of teeth. A computer-aided design (CAD) reference model (CRM) was obtained by scanning the reference typodont model using a high-precision industrial scanner (Solutionix C500, MEDIT). In addition, a CAD test model (CTM) was obtained using seven types of dental 3D scanners (desktop scanners (E1 and DOF Freedom HD) and intraoral scanners (CS3500, CS3600, Trios2, Trios3, and i500)). The 3D inspection software (Geomagic control X, 3DSystems) was used to segment the CRM according to the types of teeth and to superimpose the CTM based on the segmented teeth. The 3D accuracy of the scanner was then analyzed according to the types of teeth. One-way analysis of variance (ANOVA) was used to compare the differences according to the types of teeth in statistical analysis, and the Tukey HSD test was used for post hoc testing (α = 0.05). Both desktop and intraoral scanners showed significant differences in accuracy according to the types of teeth (P < 0.001), and the accuracy of intraoral scanners tended to get worse from anterior to posterior. Therefore, when scanning a complete arch using an intraoral scanner, the clinician should consider the tendency for the accuracy to decrease from anterior to posterior.

scholarly journals Tooth discoloration induced by apical plugs with hydraulic calcium silicate-based cements in teeth with open apices—a 2-year in vitro study

2021 ◽  
Author(s):  
Ralf Krug ◽  
C. Ortmann ◽  
S. Reich ◽  
B. Hahn ◽  
G. Krastl ◽  
...  
Keyword(s):  
Calcium Silicate ◽  
In Vitro Study ◽  
Color Difference ◽  
Blood Contamination ◽  
Tooth Color ◽  
Color Changes ◽  
Gutta Percha ◽  
Tooth Discoloration ◽  
Post Hoc

Abstract Objectives To assess tooth discoloration induced by different hydraulic calcium silicate-based cements (HCSCs), including effects of blood and placement method. Materials and methods Eighty bovine teeth cut to a length of 18 mm (crown 8 mm, root 10 mm) were randomly assigned to 10 groups (n = 8), receiving orthograde apical plug treatment (APT). Apical plugs were 4 mm in length and made of ProRoot MTA (Dentsply), Medcem MTA (Medcem), TotalFill BC RRM Fast Set Putty (Brasseler), or Medcem Medical Portland Cement (Medcem) plus bismuth oxide (Bi2O3) with and without bovine blood. Further, orthograde (with or without preoperative adhesive coronal dentin sealing) and retrograde APT were compared. Teeth were obturated with gutta-percha and sealer, sealed with composite and stored in distilled water. Tooth color was measured on apical plug, gutta-percha/sealer, and crown surface before treatment versus 24 h, 1, 3, 6, 12, and 24 months after treatment by spectrophotometry. Color difference (ΔE) values were calculated and analyzed by Shapiro–Wilk test, ANOVA with post hoc tests, Friedman test, t test, and post hoc tests with Bonferroni correction (α = .05). Results Tooth discoloration occurred in all groups with no significant differences between HCSCs (p > .05). After 24 months, color changes were prominent on roots but insignificant on crowns. Blood contamination induced a significantly decreased luminescence (p < .05). Blood had a stronger impact on tooth color than Bi2O3. No relevant effects of retrograde placement (p > .05) or preoperative dentin sealing (p > .05) were detected. Conclusions Apical plugs of the tested HCSCs cause discoloration of bovine roots, but not discoloration of bovine tooth crowns within a 24-month period. Clinical relevance APT should be performed carefully while avoiding direct contact with the coronal dentin, and in that case no aesthetic impairments occur.

scholarly journals Potential of different fluoride gels to prevent erosive tooth wear caused by gastroesophageal reflux

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Philipp Körner ◽  
Luca Georgis ◽  
Daniel B. Wiedemeier ◽  
Thomas Attin ◽  
Florian J. Wegehaupt
Keyword(s):  
Gastroesophageal Reflux ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Tooth Wear ◽  
Control Group ◽  
Erosive Tooth Wear ◽  
Custom Made ◽  
Post Hoc ◽  
Bovine Enamel

Abstract Background This in-vitro-study aimed to evaluate the potential of different fluoride gels to prevent gastroesophageal reflux induced erosive tooth wear. Methods Surface baseline profiles of a total of 50 bovine enamel specimens [randomly assigned to five groups (G1–5)] were recorded. All specimens were positioned in a custom made artificial oral cavity and perfused with artificial saliva (0.5 ml/min). Reflux was simulated 11 times a day during 12 h by adding HCl (pH 3.0) for 30 s (flow rate 2 ml/min). During the remaining 12 h (overnight), specimens were stored in artificial saliva and brushed twice a day (morning and evening) with a toothbrush and toothpaste slurry (15 brushing strokes). While specimens in the control group (G1) did not receive any further treatment, specimens in G2–5 were coated with different fluoride gels [Elmex Gelée (G2); Paro Amin Fluor Gelée (G3); Paro Fluor Gelée Natriumfluorid (G4); Sensodyne ProSchmelz Fluorid Gelée (G5)] in the evening for 30 s. After 20 days, surface profiles were recorded again and enamel loss was determined by comparing them with the baseline profiles. The results were statistically analysed using one-way analysis of variance (ANOVA) followed by Tukey`s HSD post-hoc test. Results The overall highest mean wear of enamel (9.88 ± 1.73 µm) was observed in the control group (G1), where no fluoride gel was applied. It was significantly higher (p < 0.001) compared to all other groups. G2 (5.03 ± 1.43 µm), G3 (5.47 ± 0.63 µm, p = 0.918) and G4 (5.14 ± 0.82 µm, p > 0.999) showed the overall best protection from hydrochloric acid induced erosion. Enamel wear in G5 (6.64 ± 0.86 µm) was significantly higher compared to G2 (p = 0.028) and G4 (p = 0.047). Conclusions After 20 days of daily application, all investigated fluoride gels are able to significantly reduce gastroesophageal reflux induced loss of enamel.

scholarly journals Impact of refrigeration on the surface hardness of hybrid and microfilled composite resins

2009 ◽  
Vol 20 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Fernando Henrique Ruppel Osternack ◽  
Danilo Biazzetto de Menezes Caldas ◽  
Rodrigo Nunes Rached ◽  
Sérgio Vieira ◽  
Jeffrey A. Platt ◽  
...  
Keyword(s):  
Room Temperature ◽  
Surface Hardness ◽  
In Vitro Study ◽  
Knoop Hardness ◽  
Composite Resins ◽  
Bottom Surface ◽  
Steel Mold ◽  
Polymerization Condition ◽  
Post Hoc

This in vitro study evaluated the Knoop hardness of the composite resins Charisma® (C) and Durafill VS® (D) polymerized in 3 different conditions: at room temperature (A) (23 ± 1°C); refrigerated at 4 ± 1°C and immediately photo-activated after removal from the refrigerator (0); and, refrigerated at 4 ± 1°C and photo-activated after a bench time of 15 min at room temperature (15). One hundred and twenty specimens (4 mm diameter and 2 mm depth) were made using a stainless steel mold and following manufacturer's instructions. All specimens were tested immediately after polymerization (I) and after 7 days of water storage in the dark at room temperature (7d). The data were subjected to ANOVA and post-hoc Tukey's test (a=0.05). On the top surface, CAI was statistically similar to C15I and DAI to D15I (p>0.05). On the bottom surface, CAI presented higher hardness values when compared to COI and C15I (p<0.05). The D groups showed no significant differences (p>0.05) on the bottom surfaces for any tested polymerization condition. After 7 days of storage, the Knoop hardness decreased significantly (p<0.05) for groups C7d and D7d except for C07d, which was not different from COI at either surface (p>0.05). D07d showed higher Knoop hardness (p<0.05) values on the top surface when compared to the other groups.

scholarly journals Depth-Related Curing Potential of Ormocer- and Dimethacrylate-Based Bulk-Fill Composites

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6753
Author(s):  
Ramona S. Oltramare ◽  
Reto Odermatt ◽  
Phoebe Burrer ◽  
Thomas Attin ◽  
Tobias T. Tauböck
Keyword(s):  
Double Bond ◽  
Repeated Measures ◽  
In Vitro Study ◽  
High Viscosity ◽  
Degree Of Conversion ◽  
Double Bond Conversion ◽  
Nanohybrid Composite ◽  
Post Hoc ◽  
One Way Anova

The aim of this in vitro study was to investigate the degree of C=C double bond conversion of high-viscosity dimethacrylate- or ormocer-based bulk-fill composites as a function of measurement depth. Four bulk-fill composites (Tetric EvoCeram Bulk Fill, x-tra fil, SonicFill, and Bulk Ormocer) and the conventional nanohybrid composite Tetric EvoCeram were applied in standardized Class II cavities (n = 6 per group) and photoactivated for 20 s at 1350 mW/cm2. The degree of conversion of the composites was assessed using Fourier-transform infrared spectroscopy at seven measurement depths (0.15, 1, 2, 3, 4, 5, 6 mm). Data were analyzed using repeated measures ANOVA and one-way ANOVA with Bonferroni post-hoc tests (α = 0.05). The investigated bulk-fill composites showed at least 80% of their maximum degree of conversion (80% DCmax) up to a measuring depth of at least 4 mm. Tetric EvoCeram Bulk Fill and Bulk Ormocer achieved more than 80% DCmax up to a measuring depth of 5 mm, x-tra fil up to 6 mm. The conventional nanohybrid composite Tetric EvoCeram achieved more than 80% DCmax up to 3 mm. In contrast to the conventional composite, the investigated ormocer- and dimethacrylate-based bulk-fill composites can be photo-polymerized in thick layers of up to at least 4 mm with regard to their degree of C=C double bond conversion.

scholarly journals The Accuracy and Reliability of Tooth Shade Selection Using Different Instrumental Techniques: An In Vitro Study

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7490
Author(s):  
Nattapong Sirintawat ◽  
Tanyaporn Leelaratrungruang ◽  
Pongsakorn Poovarodom ◽  
Sirichai Kiattavorncharoen ◽  
Parinya Amornsettachai
Keyword(s):  
Intraclass Correlation ◽  
In Vitro Study ◽  
Control Group ◽  
Intraoral Scanner ◽  
Control Groups ◽  
B Values ◽  
Cie Lab ◽  
And Control ◽  
Shade Selection

This study aimed to investigate and compare the reliability and accuracy of tooth shade selection in the model using 30 milled crowns via five methods: (1) digital single-lens reflex (DSLR) camera with twin flash (TF) and polarized filter (DSLR + TF), (2) DSLR camera with a ring flash (RF) and polarized filter (DSLR + RF), (3) smartphone camera with light corrector and polarized filter (SMART), (4) intraoral scanner (IOS), and (5) spectrophotometer (SPEC). These methods were compared with the control group or manufacturer’s shade. The CIE Lab values (L, a, and b values) were obtained from five of the methods to indicate the color of the tooth. Adobe Photoshop was used to generate CIE Lab values from the digital photographs. The reliability was calculated from the intraclass correlation based on two repetitions. The accuracy was calculated from; (a) ΔE calculated by the formula comparing each method to the control group, (b) study and control groups were analyzed by using the Kruskal–Wallis test, and (c) the relationship between study and control groups were calculated using Spearman’s correlation. The reliability of the intraclass correlation of L, a, and b values obtained from the five methods showed satisfactory correlations ranging from 0.732–0.996, 0.887–0.994, and 0.884–0.999, respectively. The ΔE from all groups had statistically significant differences when compared to the border of clinical acceptance (ΔE = 6.8). The ΔE from DSLR + TF, DSLR + RF, SMART, and SPEC were higher than clinical acceptance (ΔE > 6.8), whereas the ΔE from IOS was 5.96 and all of the L, a, and b values were not statistically significantly different from the manufacturer’s shade (p < 0.01). The ΔE of the DSLR + RF group showed the least accuracy (ΔE = 19.98), whereas the ∆E of DSLR + TF, SMART, and SPEC showed similar accuracy ∆E (ΔE = 10.90, 10.57, and 11.57, respectively). The DSLR camera combined with a ring flash system and polarized filter provided the least accuracy. The intraoral scanner provided the highest accuracy. However, tooth shade selection deserves the combination of various techniques and a professional learning curve to establish the most accurate outcome.

scholarly journals The Effect of the Bioactive Glass and the Er:YAG Laser on the Remineralization of the Affected Dentin: A Comparative In Vitro Study

2020 ◽  
Vol 11 (2) ◽  
pp. 160-166
Author(s):  
Mohammad Javad Moghaddas ◽  
Horieh Moosavi ◽  
Sara Yaghoubirad ◽  
Nasim Chiniforush
Keyword(s):  
Bioactive Glass ◽  
In Vitro Study ◽  
Control Group ◽  
Dentinal Tubule ◽  
Glass Ionomer ◽  
Significant Difference ◽  
Post Hoc ◽  
Caries Lesions ◽  
Cavity Floor

Introduction: The purpose of this study was to compare the effect of the bioactive glass, the glass ionomer, and the Erbium YAG laser as liners on the remineralization of the affected dentin. Methods: The present study was conducted on 64 healthy extracted human molars divided into 4 groups, 1 control group and 3 experimental groups. After artificially inducing dentinal caries lesions, each of the experimental groups was applied to the cavity floor and then restored with a composite. The samples were stored after thermocycling in an incubator for two months. Finally, the hardness of the cavity floor was measured at 3 depths of 20, 50 and 100 μm by the Vickers microhardness tester. The dentin conditions underneath the liners were also evaluated with FESEM. Statistical analysis was performed by two-way ANOVA and the post-hoc Games-Howell test (P<0.05). Results: Among the groups, the lowest microhardness value was in the control group (P<0.05) except at a depth of 100 μm; therefore, there was no significant difference between the control group and the bioactive glass (P>0.05). The laser group had the highest microhardness value, which was significantly different from the control group (P<0.05). There was a significant difference between the laser and bioactive glass (P<0.05), except at a depth of 20 μm. The laser and glass ionomer had only a significant difference at a depth of 100 μm (P<0.05). The microhardness value induced by glass ionomer was higher than bioactive glass, which in no depth was significant (P>0.05). Partial dentinal tubule occlusion was observed with FESEM in each of the experimental groups as compared to the control group. Conclusion: The microhardness values were higher in all groups than in the control group. The laser might be more successful in remineralization than the other ones.

scholarly journals Comparative evaluation of fine detail reproduction of six different die materials- An in-Vitro study

2021 ◽  
Vol 7 (3) ◽  
pp. 166-171
Author(s):  
Pronoy Mukhopadhyay ◽  
Sattyam Wankhade ◽  
Jyoti Wankhade ◽  
Arun Khalikar
Keyword(s):  
In Vitro Study ◽  
Tooth Surface ◽  
Type Iv ◽  
Fine Detail ◽  
Die Materials ◽  
Die Material ◽  
Type V ◽  
Post Hoc ◽  
Conventional Type

The precise outcome of any indirect casting, depends on the various procedures and materials involved through all its stages. The accurate fit against the prepared surface and the adaptation against the prepared margin depends on how accurately the tooth surface is captured in the impression made and how well it is reproduced in the die This study aims to study and compare the property of fine detail reproduction amongst six die materials.Over a pre-calibrated master die using custom tray, an impression record is made and poured using the six different die materials and the finest line reproduced is visualized under an optical fluorescent microscope at 50X magnification.The data obtained were statistically analysed using one-way ANOVA and subsequently assessed by post-hoc Tukey’s comparison to identify any significant differences between the groups. Epoxy resin die material (1.93 mm) showed a consistently excellent fine detail reproduction, followed by conventional Type V gypsum and Synthetic gypsum (15.91 mm), while Resin modified-Type IV and Type V and conventional Type IV gypsum dies (21.86mm) showed the least accuracy in fine reproduction.

scholarly journals Effect of Hydrothermal Aging and Beverages on Color Stability of Lithium Disilicate and Zirconia Based Ceramics

Medicina ◽  
2019 ◽  
Vol 55 (11) ◽  
pp. 749 ◽  
Author(s):  
Satheesh B. Haralur ◽  
Noura Raqe S. Alqahtani ◽  
Fatimah Alhassan Mujayri
Keyword(s):  
Green Tea ◽  
In Vitro Study ◽  
Color Stability ◽  
Lithium Disilicate ◽  
Color Difference ◽  
Hydrothermal Aging ◽  
Monolithic Zirconia ◽  
Post Hoc ◽  
Coloring Agents

Background and aim: All-ceramic prosthesis is widely used in modern dental practice because of its improved physico-mechanical and optical properties. These restorations are exposed to coloring agents from various nutrition and beverages in the oral cavity. Long-term color stability is critical for the success of these restorative materials. The purpose of this in vitro study was to assess the effect of common beverages and mouthwash on the color stability of lithium disilicate (LD), monolithic zirconia (MZ) and bilayer zirconia (BZ) surfaces. Material and methods: Thirty disc-shaped specimens from each material were fabricated; each group was subdivided (n = 10) according to coffee, green tea and chlorhexidine immersion solutions. The baseline color of ceramic discs was recorded according to the CIE L*a*b* system with a portable spectrophotometer. The second measurement was recorded after 3000 thermocycling and immersion in coloring agents for 7 days. The mean color difference was calculated and data were compared with Kruskal-Wallis and Mann-Whitney post hoc tests (0.05). Results: ΔE values for LD with the immersion of coffee, tea, and Chlorhexidine gluconate (CHG) were 1.78, 2.241 and 1.58, respectively. Corresponding ΔE values for MZ were 5.60, 5.19, and 4.86; marginally higher than the clinically acceptable level of 3.5. Meanwhile, BZ showed better color stability compared to MZ with ΔE values of 4.22, 2.11 and 1.43. Conclusion: Among the ceramics evaluated, LD ceramic was found to be more color stable, while MZ ceramics displayed a higher susceptibility to discoloration. MZ and BZ ceramic colors were significantly altered with coffee immersion, while LD ceramics were more affected by green tea.

scholarly journals Superelasticity and force plateau of nickel-titanium springs: an in vitro study

2016 ◽  
Vol 21 (3) ◽  
pp. 46-55 ◽  
Author(s):  
Camila Ivini Viana Vieira ◽  
Sergei Godeiro Fernandes Rabelo Caldas ◽  
Lídia Parsekian Martins ◽  
Renato Parsekian Martins
Keyword(s):  
Analysis Of Variance ◽  
In Vitro Study ◽  
Nickel Titanium ◽  
Vitro Study ◽  
Lack Of Information ◽  
Activation Force ◽  
Post Hoc

abstract Objective: This paper analyzed whether nickel-titanium closed coil springs (NTCCS) have a different superelastic (SE) behavior according to activation and whether their force plateau corresponds to that informed by the manufacturer. Methods: A total of 160 springs were divided into 16 subgroups according to their features and activated proportionally to the length of the extensible part (NiTi) of the spring (Y). The force values measured were analyzed to determine SE rates and force plateaus, which were mathematically calculated. These plateaus were compared to those informed by the manufacturer. Analysis of variance was accomplished followed by Tukey post-hoc test to detect and analyze differences between groups. Results: All subgroups were SE at the activation of 400% of Y length, except for: subgroups 4B and 3A, which were SE at 300%; subgroups 4E and 4G, which were SE at 500%; and subgroup 3C, which was SE at 600%. Subgroup 3B did not show a SE behavior. Force plateaus depended on activation and, in some subgroups and some activations, were similar to the force informed. Conclusions: Most of the springs showed SE behavior at 400% of activation. Force plateaus are difficult to compare due to lack of information provided by manufacturers.

Sign in / Sign up

Export Citation Format

Share Document