The influence of different screw tightening forces on the vertical misfit of implant-supported frameworks

OBJECTIVES: The present in vitro study was designed to compare the differences in the vertical misfit of implant-supported frameworks using three different forces for tightening the bridge locking screws: fastening by hand until first resistance, and using torque drivers with 10 and 20Ncm. METHODS: The investigation was conducted based on the results given by 9 six-unit nickel-chromium (2 abutments/ 4 pontics) screw-retained implant-supported frameworks. The structures were exposed to simulated porcelain firings. The marginal misfit measurements were made using a traveling measuring microscope at selected screw tightening forces: fastening by hand until first resistance, and using torque drivers with 10 and 20Ncm. The results were submitted to one-way ANOVA with repeated measures on one factor, and post hoc pairwise comparisons using Tukey test (5%). RESULTS: The mean marginal misfit of the frameworks, fastening the screws by hand until first resistance, was 41.56µm (SD±12.45µm). The use of torque driver devices caused a significant reduction in marginal opening (p<0.05). With the lowest torque available (10Ncm), the mean marginal discrepancy at the abutment-framework interface was reduced an average of 52% to a mean marginal opening of 19.71µm (SD±2.97µm). After the use of the 20Ncm torque driver, the mean marginal discrepancy of the frameworks was reduced an average of 69% to a mean marginal opening of 12.82µm (SD±4.0µm). Comparing the use of torque drivers with 10 and 20 Ncm torque, the means are not significantly different from one another. CONCLUSION: The seating force has an important effect on the vertical misfit measurements, once it may considerably narrow the vertical misfit gaps at the abutment-framework interface, thus leading to a misjudgment of the real marginal situation.

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

Materials ◽

10.3390/ma14226753 ◽

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.

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An in vitro Comparison of Marginal Accuracy in Temporary Crowns

Journal of Contemporary Dentistry ◽

10.5005/jp-journals-10031-1050 ◽

2013 ◽

Vol 3 (3) ◽

pp. 121-126 ◽

Cited By ~ 1

Author(s):

Fahad Umer ◽

Samira Adnan ◽

Farhan Raza Khan

Keyword(s):

Computer Software ◽

Marginal Gap ◽

Luting Cement ◽

Marginal Discrepancy ◽

The Mean ◽

Post Hoc ◽

To Receive ◽

Mandibular First Molar ◽

One Way Anova

ABSTRACT Purpose To compare the marginal accuracy of temporary crowns in vitro, using two autopolymerizing temporary crown materials. Materials and Methods Polyethyl methacrylate and bis-acryl composite were used to make 15 temporary crowns each, on an ivorine mandibular first molar, prepared as to receive a porcelain-fused-to-metal (PFM) crown. Matrices were made of polyvinyl siloxane impressions of a lower typodont arch. After crowns were fabricated, margins of the crowns were trimmed under magnification. Afterwards, margins of prepared tooth and crowns were marked. Each tooth-crown assembly was then observed under microscope (4×). With digital images of each surface, gap between margins of crown and preparation margin was measured in millimeters using computer software, after calibration. Two examiners made the measurements. Independent samples t-test and one-way ANOVA with Bonferroni post hoc analysis were applied to determine the mean marginal gap. Results Bis-acryl composite crowns exhibited 0.2 mm (SD ± 0.11) mean gap with greatest discrepancy at buccal margins. Mean gap with polyethyl methacrylate crowns was 0.3 mm (SD ± 0.17) with buccal and mesial margins exhibiting the greatest marginal discrepancy, at α <0.001. Conclusion Both materials did not exhibit ideal marginal accuracy, but temporary luting cement film thickness would compensate for the gap observed in the margins of bis-acryl composite crowns. How to cite this article Adnan S, Khan FR, Umer F. An in vitro Comparison of Marginal Accuracy in Temporary Crowns. J Contemp Dent 2013;3(3):121-126.

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Effect of clasp type and pullout location on clasp retention in different environment: In vitro study

European Journal of Dentistry ◽

10.4103/ejd.ejd_70_17 ◽

2017 ◽

Vol 11 (02) ◽

pp. 216-220 ◽

Cited By ~ 1

Author(s):

Bilal Mourshed ◽

Fuad Abdo Al-Sabri ◽

Nashwan Ahmed Qaed ◽

Nader Alaizari ◽

Hashem Motahir Al-Shamiri ◽

...

Keyword(s):

Statistical Analysis ◽

In Vitro Study ◽

Retentive Force ◽

Crosshead Speed ◽

Tukey Test ◽

Retention Force ◽

Test Models ◽

Molar Teeth ◽

One Way Anova

ABSTRACT Objective: The purpose of this study was to investigate the importance of pullout location and clasp types in two different environments to dislodge the clasp. Materials and Methods: Mandibular test models with natural premolars and molar teeth were used to test four types of clasp (each 12) (Akers, Rest plate Akers, Half and Half, and Ring clasp) with three different pullout location for each type (ring on the rest, loop on the saddle, and wax arising from both rests) in dry and natural fresh saliva environment. Each clasp was pulled out 10 times with a crosshead speed of 10 mm/min, and the force required to withdraw each was measured. Statistical Analysis Used: A one-way ANOVA and Tukey test were used. Results: The ring on the saddle pullout location has the highest retention force while ring on the rest was the lowest. In addition, ring clasp has the highest retention force. Conclusion: Clasp type and pullout location had a significant effect on the retentive force.

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In Vitro Evaluation of Microleakage and Microhardness of Ethanolic Extracts of Propolis in Different Proportions Added to Glass Ionomer Cement

Journal of Clinical Pediatric Dentistry ◽

10.17796/1053-4628-40.2.136 ◽

2016 ◽

Vol 40 (2) ◽

pp. 136-140 ◽

Cited By ~ 7

Author(s):

Mustafa Altunsoy ◽

Mehmet Tanrıver ◽

Uğur Türkan ◽

Mehmet Emin Uslu ◽

Sibel Silici

Keyword(s):

Glass Ionomer Cement ◽

Antibacterial Properties ◽

Dental Practice ◽

Glass Ionomer ◽

Tukey Test ◽

Ethanolic Extracts ◽

Post Hoc ◽

One Way Anova ◽

Ionomer Cement

Objective: To evaluate the effect of ethanolic extracts of propolis (EEP) addition in different proportions to glass ionomer cement (GIC) on microleakage and microhardness of GIC. Study design: The cement was divided into four groups: one using the original composition and three with 10%, 25%, and 50% EEP added to the liquid and then manipulated. For microleakage assessment, sixty primary molars were randomly divided into four groups (n=15). Standard Class II cavities were prepared and then filled with EEP in different proportions added to GICs. Microleakage test was performed using a dye penetration method. The data were analyzed using one-way ANOVA and Mann - Whitney U tests (α = 0.05). Disc shaped specimens were prepared from the tested GIC to determine Vickers hardness (VHN). The data were analyzed using one-way ANOVA and post hoc Tukey test (α = 0.05). Results: There were no statistically significant differences between the groups in terms of microleakage (p > 0.05). There were statistically significant differences between the VHN values of groups (p < 0.05). Increasing addition of EEP to GIC statistically significantly increased VHN value of GIC (p < 0.05). Conclusions: The addition of EEP to GIC increased the microhardness of the GIC and did not adversely affect the microleakage. Thus, it might be used during routine dental practice due to its antibacterial properties

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The Effect of Glaze Coating on Wear Resistance of Some Acrylic Denture Teeth: An In Vitro Study

Avicenna Journal of Dental Research ◽

10.34172/ajdr.2021.09 ◽

2021 ◽

Vol 13 (2) ◽

pp. 47-51

Author(s):

Samaneh Abbasi ◽

Soodabe Ebrahimi ◽

Arash Shisheian ◽

Maryam Farhadian

Keyword(s):

Wear Resistance ◽

In Vitro Study ◽

Resistance Rate ◽

Vitro Study ◽

Wear Rates ◽

Denture Teeth ◽

Significant Difference ◽

The Mean ◽

Post Hoc

Background: Acrylic resin teeth wear resistance has an important role in the denture longevity. This study aimed to clarify the effect of glaze coating on wear resistance of three types of artificial acrylic teeth. Methods: In this in vitro study, the wear resistance rate of three of acrylic denture teeth (GENIUS, STON and CLASSIC) was compared with Ivoclar teeth (n=25/group). The wear resistance was measured by estimating the weight loss in pre and post removing glaze coating, following 5000 cycles in the chewing simulator device. Data analysis was made using paired t test, one-way ANOVA and Tukey’s post hoc test. Results: ANOVA test showed that there was no significant difference between the mean amount of wear of GENIUS, CLASSIC, STON and IVOCLAR teeth in the first stage (P <0.061), but this difference was significant (P <0.001) in the second stage. The result of Tukey post hoc test showed that wear rates of GENIUS were significantly lower than other groups (P<0.001). Comparison between the mean wear rates of each dental group at the first and second stages showed a significant difference between average teeth wear resistance of CLASSIC, STON and IVOCLAR in the first and second stages (P <0.001). Conclusions: In conclusion, the teeth wear resistance of STON and CLASSIC were similar to IVOCLAR. Also, after removing the glaze coating, the teeth wear resistance decreased in all groups but was not statistically significant for group GENIUS.

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Comparative in vitro study of the cleaning efficacy of AirFloss ultra and I-Prox Sulcus brushes in an orthodontic phantom model

Scientific Reports ◽

10.1038/s41598-021-81603-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hanna Boes ◽

Sören Brüstle ◽

Gholamreza Danesh ◽

Stefan Zimmer ◽

Mozhgan Bizhang

Keyword(s):

In Vitro Study ◽

White Spot Lesions ◽

Mean Values ◽

Phantom Model ◽

Before And After ◽

Tooth Surfaces ◽

The Mean ◽

Post Hoc ◽

Cleaning Efficacy

AbstractPreventing biofilm-related risks such as gingivitis and white spot lesions during orthodontic treatments is very challenging. The cleaning efficiencies of AirFloss Ultra and I-Prox P sulcus brushes were evaluated using an orthodontic phantom model. After attaching brackets onto black-coated maxillary KaVo teeth, a plaque substitute was applied. The evaluated tooth surfaces were divided into two areas. Cleaning was performed with an AirFloss Ultra with two (A-2) or four (A-4) sprays or an I-Prox P for two (I-2) or four (I-4) seconds. Images before and after cleaning were digitally subtracted, and the percentage of fully cleaned surfaces was determined (Adobe Photoshop CS5, ImageJ). Statistical analysis was performed by ANOVA and post hoc tests with Bonferroni correction (SPSS 25, p < 0.05). The mean values of total cleaning efficacy were 26.87% for I-2, 43.73% for I-4, 34.93%, for A-2 and 56.78% for A-4. The efficacy was significantly higher for A-4 than for A-2, I-4, and I-2. There were significant differences between the four groups. Repeated cleaning led to an improved result. Within the study limitations, the AirFloss Ultra with four sprays proved to be more efficient than the sulcus brush I-Prox P for cleaning.

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In vitro evaluation of marginal fit of zirconia-reinforced lithium silicate laminate veneers at two thicknesses using different CAD/CAM systems

Brazilian Dental Science ◽

10.14295/bds.2020.v23i4.2071 ◽

2020 ◽

Vol 23 (4) ◽

pp. 9p

Author(s):

Manar Ahmed El-Mahdy ◽

Ahmed Khaled Aboelfadl ◽

Marwa Mohamed Wahsh

Keyword(s):

In Vitro Study ◽

Lithium Silicate ◽

Milling Machine ◽

Marginal Fit ◽

Cad Cam ◽

Marginal Discrepancy ◽

Post Hoc ◽

Laminate Veneers ◽

Cam Systems

ABSTRACTObjective: The purpose of this in vitro study was to evaluate the marginal fit of laminate veneers made of zirconia-reinforced lithium silicate with two thicknesses using different CAD/CAM systems. Material and methods: 42 Laminate veneers milled from zirconia-reinforced lithium silicate were divided into three main groups according to milling machine used into: group X5, laminate veneers fabricated by inLab MCX5 milling machine; group CM, laminate veneers fabricated by Ceramill motion 2; and group XL, laminate veneers fabricated by inLab MCXL. Each group was divided into two subgroups according to veneer thickness into: subgroup I, 0.5 mm thickness laminate veneers and subgroup II, 0.3 mm thickness laminate veneers. The marginal fit was measured using stereomicroscope. The results were tabulated and statistically analyzed using two-way ANOVA test followed by Tukey’s post hoc test. Comparisons of main and simple effects were done utilizing Bonferroni correction (P ? 0.05). Results: The mean (±SD) highest marginal discrepancy was recorded in subgroup BII at 85.45±1.82 µm while the least mean marginal discrepancy was recorded in subgroup AI 71.24±2.64 µm. Conclusion: Both thicknesses (0.5 mm thickness and 0.3 mm thickness) and all tested CAD/CAM systems produced zirconia-reinforced lithium silicate laminate veneers with clinically acceptable marginal gaps; however, the closed CAD/CAM systems produced veneers with superior marginal fit than open systems at 0.3 mm thickness. The CAD/CAM system with the 5-axis milling machine produced the best marginal fit with 0.5 mm thickness. KEYWORDS Marginal fit; Zirconia-reinforced lithium silicate; Laminate veneers; CAD/CAM; Milling machines. RESUMOObjetivo: O objetivo deste estudo in vitro foi avaliar a adaptação marginal de facetas laminadas de silicato de lítio reforçado com zircônia com duas espessuras, utilizando diferentes sistemas CAD / CAM. Material e métodos: 42 facetas laminadas fresadas a partir de silicato de lítio reforçado com zircônia foram divididos em três grupos principais de acordo com a fresadora usada em: grupo X5, facetas laminadas fabricados pela fresadora inLab MCX5; grupo CM, facetas laminadas fabricados por Ceramill motion 2; e grupo XL, facetas laminadas fabricados pelo inLab MCXL. Cada grupo foi dividido em dois subgrupos, de acordo com a espessura do laminado, em: subgrupo I, facetas laminadas com 0,5 mm de espessura e subgrupo II, facetas laminadas com espessura de 0,3 mm. A adaptação marginal foi medida usando estereomicroscópio. Os resultados foram tabulados e analisados estatisticamente usando o teste ANOVA de dois fatores seguido pelo teste post hoc de Tukey. Comparações dos efeitos principais e simples foram realizadas utilizando a correção de Bonferroni (P ?0,05). Resultados: A maior discrepância marginal média (± DP) foi registrada no subgrupo BII em 85,45 ± 1,82 µm, enquanto a menor discrepância marginal média foi registrada no subgrupo AI 71,24 ± 2,64 µm. Conclusão: Ambas as espessuras (0,5 mm e 0,3 mm) e todos os sistemas CAD / CAM testados produziram facetas de laminado de silicato de lítio reforçadas com zircônia com lacunas clinicamente aceitáveis. No entanto, os sistemas CAD / CAM fechados produziam facetas com adaptação marginal superior aos sistemas abertos com 0,3 mm de espessura. O sistema CAD / CAM com a fresadora de 5 eixos produziu a melhor adaptação marginal com 0,5 mm de espessura.PALAVRAS-CHAVE Adaptação marginal; Silicato de lítio reforçado com zircônia; Facetas laminados; CAD / CAM; Fresadoras.

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Surface Hardness of Hybrid Ionomer with Different Curing Time (In Vitro Study)

UI Proceedings on Health and Medicine ◽

10.7454/uiphm.v1i0.32 ◽

2017 ◽

Vol 1 ◽

Author(s):

Arfita Sipahutar ◽

Astrid Yudhit ◽

Rusfian Rusfian

Keyword(s):

Standard Deviation ◽

Surface Hardness ◽

In Vitro Study ◽

Hardness Test ◽

Curing Time ◽

Mean Values ◽

The Mean ◽

One Way Anova ◽

Group 1

Objective: The aim of this study was to evaluate the surface hardness of hybrid ionomer with different curing times (20, 30, 40, and 50 seconds).Methods: This was an experimental laboratory with posttest only group design. Twenty-four disk shape hybrid ionomer specimens with a diameter of 5 mm and 2 mm in thickness were prepared and polymerized with Quartz Tungsten Halogen (QTH) for 20, 30, 40, and 50 seconds as group 1, 2, 3, and 4 respectively. All samples were immersed in distilled water under 37°C temperature for 24 hours as initial treatment. Surface hardness test was done using Vickers Hardness Test with load 50 gf for 20 second. The Data was analyzed with one way ANOVA (p ≤ 0.05).Results: Using one way anova test (p ≤ 0.05) shows the mean and standard deviation of the group 1 is 25,900 ± 2,5659VHN; group 2 is 29,800 ± 1,1983 VHN; group 3 is 31,283 ± 0,5037 VHN; group 4 is 36, 183 ± 2,3430 VHN and the obtained value p = 0.000 (p ≤ 0.05).The mean values and standard deviation were 25.900 ± 2.5659 VHN; 29.800 ± 1.1983 VHN; 31.283 ±0.5037 VHN; 6.183 ± 2.3430 VHN for group 1, 2, 3, and 4 respectively. Statistic analyzed showed a significant different among groups with p value =0.000 (p < 0.05).Conclusion There are significant differences in surface hardness of hybrid ionomer with different curing time (20, 30,40, and 50 seconds). The longer curing time will increase the surface hardness of hybrid ionomer.

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Estimation of Total Fluoride Concentration, Total Soluble Fluoride Concentration and pH among Various Brands of Toothpastes

JOURNAL FOR CLINICAL AND DIAGNOSTIC RESEARCH ◽

10.7860/jcdr/2021/46804.14598 ◽

2021 ◽

Author(s):

Praneetha D Rani ◽

Vijaya Hegde

Keyword(s):

Group Analysis ◽

Fluoride Concentration ◽

In Vitro Study ◽

Significant Difference ◽

The Mean ◽

The Difference ◽

Institute Of Technology ◽

Level Of Significance ◽

Post Hoc

Introduction: Fluoride toothpastes are a major reason for the decline in dental caries globally. For fluoride toothpaste to be effective, an adequate amount of Total Soluble Fluoride (TSF) must be available in the toothpastes. Aim: To determine and compare the Total Fluoride (TF), TSF and pH among various toothpaste brands. Materials and Methods: An in-vitro study was conducted during October 2019 on 20 toothpaste samples, which belonged to four groups namely, herbal toothpastes group, nonherbal toothpastes group, medicated toothpastes group and kids toothpastes group. Analysis of the samples was done at the Department of Environmental Engineering Laboratory, National Institute of Technology, Surathkal, Karnataka, India. The TF and the TSF concentration was determined using fluoride ion electrode. The pH was determined using pH meter. Statistical analysis was performed using Statistical Package for Social Sciences (SPSS version 19.0). Analysis of variance (ANOVA) was used by Tukey’s post-hoc test to determine the difference between groups. The level of significance was kept at 0.05. Results: The results showed that there was a significant difference between the toothpaste types for mean TF concentration (p=0.004). The post-hoc test showed that there was a significant difference between herbal and nonherbal toothpastes (p=0.041) where the mean TF concentration for nonherbal toothpastes was 1095.20 ppm when compared to herbal toothpastes was 704.40 ppm. The results showed that there was a siginificant difference between the toothpaste types for Mean TSF concentration (p<0.003). There was a significant difference between medicated and kids toothpastes (p=0.024) where the mean total soluble fluoride concentration for medicated toothpastes was 938.60 ppm when compared to the kids toothpastes was 521.20 ppm. Conclusion: The present study showed that pH of all the toothpastes were either neutral or alkaline and the TSF concentration was less when compared to TF concentrations.

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Effect of Abutment Geometry and Luting Agents on the Vertical Marginal Discrepancy of Cast Copings on Implant Abutments: An In Vitro Study

International Journal of Dentistry ◽

10.1155/2021/9950972 ◽

2021 ◽

Vol 2021 ◽

pp. 1-7

Author(s):

Jose Rosas ◽

Frank Mayta-Tovalino ◽

Violeta Malpartida-Carrillo ◽

Arnaldo Munive Degregori ◽

Roman Mendoza ◽

...

Keyword(s):

In Vitro Study ◽

Reference Points ◽

Luting Agents ◽

Luting Agent ◽

Implant Abutments ◽

Implant Abutment ◽

Marginal Discrepancy ◽

Student’S T ◽

Post Hoc

Aim. Vertical marginal discrepancy (VMD) influences the success of implant-supported restorations. However, there is little literature that has investigated the influence of geometry and cementing agent on changes in VMD of metal copings on implant abutments. The objective was to evaluate the effect of the geometry of the abutment and cementing agents on VMD. Methods. Cast copings were cemented on implant abutments customized cylindrical (4, 5.5, and 7 mm) and on hexagonal implant abutments (4 mm) cemented or uncemented molded copings were placed (n = 4, totally 64 samples) with different luting agents. The VMD of the copings were measured in the coping-abutment interface at three reference points using a stereomicroscope. The independent Student’s t test was used for comparison between the two different abutment walls. The post hoc statistical analysis was performed by the Tukey test. Results. There was a significant VMD increase between noncemented and cemented cast copings using different luting agents. Abutment geometry and luting agents significantly influenced the VMD p ≤ 0.05 . Cylindrical abutment at 7 mm in height cemented with different luting agent tested showed significantly higher VMD values than cylindrical abutments of 4 mm p = 0.019 . Hexagonal abutments with a 4 mm height showed significantly higher VMD values than cylindrical 4 mm abutments using zinc oxide noneugenol and glass ionomer cements p = 0.032 . Conclusions. Abutment geometry and luting agents influence the VMD of cast copings cemented on implant abutment. The higher the cylindrical abutment, the greater the VMD, and hexagonal wall abutments promote greater marginal gap.

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