scholarly journals Efficacy of Palatal Applications on Fracture Resistance of Reattached Maxillary Central Incisors: AnIn VitroStudy

2017 ◽  
Vol 2017 ◽  
pp. 1-5
Author(s):  
İhsan Yikilgan ◽  
Nagihan Guven ◽  
Cemile Kedıcı Alp ◽  
Emre Tokar ◽  
Ozgur Topuz ◽  
...  

The purpose of this study was to evaluate the effects of different palatal applications on fracture strength of the fractured anterior tooth. Sixty caries-free human maxillary incisors were used. Endodontic treatments of the teeth were performed. Then, the teeth were divided randomly into five groups (n=12). Crowns of all teeth in groups A–D were cut with diamond discs at a fixed distance of 3 mm from the incisal margin in a plane normal to the buccal surface. In all groups, coronal fragments were reattached to the remaining teeth by bonding with hybrid composite resin. After then, the teeth were restored to the following; group A, bonding and palatal laminate; group B, bonding and creation of a vertical groove; group C, bonding and creation of two slot grooves; group D, bonding only; and group E, intact tooth. It was lesser in group B than in groups C and E (p=0.007andp=0.006, resp.) and lesser in group D than in groups A, C, and E (p=0.002,p<0.001, andp<0.001, resp.). Within the limitations of this in vitro study, it can be concluded that methods employing palatinal laminate and small grooves are clinically feasible for the reattachment of tooth fragments to incisors.

2012 ◽  
Vol 624 ◽  
pp. 98-102
Author(s):  
Yao Kun Zhang ◽  
Long Quan Shao ◽  
Ruo Yu Liu ◽  
Lin Lin Wang ◽  
Jun Ai ◽  
...  

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.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Zahraa Abdulaali Al-Ibraheemi ◽  
Huda Abbas Abdullah ◽  
Nada Abdlameer Jawad ◽  
Julfikar Haider

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.


2018 ◽  
Vol 11 (3) ◽  
pp. 1689-1697 ◽  
Author(s):  
Zainab M. Jassim ◽  
Manhal A. Majeed

The objective of this in vitro study was to evaluate and compare the fracture strength of monolithic crowns fabricated from five different all-ceramic CAD/CAM materials (lithium disilicate, zirconia, reinforced composite, hybrid dental ceramic, and zirconia-reinforced lithium silicate) using single load to failure test. Forty sound human maxillary first premolar teeth extracted for orthodontic purposes were selected for use in this study. Teeth were prepared according to a standard protocol with 1 mm deep chamfer finishing line, 4 mm axial height with planer occlusal reduction and 6º total convergence angle. Teeth were then divided into five groups of eight teeth each according to the material used for the fabrication of the monolithic crowns as follow: Group A: Crowns fabricated from lithium disilicate (IPS e.max CAD, Ivoclar Vivadent), Group B: Crowns fabricated from zirconia (CEREC Zirconia, Dentsply Sirona), Group C: Crowns fabricated from reinforced composite (BRILLIANT Crios, COLTENE), Group D: Crowns fabricated from hybrid dental ceramic (VITA ENAMIC, VITA Zahnfabric), Group E: Crowns fabricated from zirconia-reinforced lithium silicate (CELTRA DUO, Dentsply Sirona). Teeth of all groups were then scanned with CEREC Omnicam digital intraoral scanner and the crowns were then designed using CEREC Premium software (version 4.4.4) and milled using CEREC MC XL milling unit. Post-milling, crowns of each group were subjected to either a firing procedure or to a polishing only according to the manufacturer's instructions of each material. The internal surfaces of the crowns of each group were then subjected to surface treatment according to the manufacturer's instructions of each material and the crowns were then cemented on their respective teeth using a universal dual-cured adhesive resin cement (Duo-Link Universal, Bisco Inc.). All teeth with the cemented crowns were then stored in deionized distilled water at room temperature for 24 hours before testing. All samples were then subjected to compressive axial loading until fracture in computer-controlled universal testing machine (Zwick Z010, Ulm, Germany) at a crosshead speed of 0.5 mm/min. The data were statistically analyzed using one-way ANOVA test and LSD test at a level of significance of 0.05. The results of this study showed that the highest mean value of fracture strength was recorded by Group B (2337.37), followed by Group C (1880.59), Group E (1404.49), Group A (1085.39) and Group D (767.06), respectively with statistically highly significant differences among the different groups (p<0.01). From the results of this study, it seems that the differences in the chemical composition and microstructure of the tested all-ceramic CAD/CAM materials may be responsible for the differences in the fracture strength of the fabricated crowns.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 436
Author(s):  
Lucía Barallat ◽  
María Arregui ◽  
Sandra Fernandez-Villar ◽  
Blanca Paniagua ◽  
Andrés Pascual-La Rocca

There is ample evidence to support the use of endocrowns to restore endodontic teeth. However, the influence of the position of the interproximal margins on fracture strength has not yet been studied. The aim was to determine the relationship between the apicocoronal position of the interproximal restorative margins and fracture resistance in nonvital teeth restored with CAD/CAM endocrown overlays. Forty extracted human maxillary premolars were prepared for endocrown overlay restorations without ferrule on the interproximal aspects and classified according to the position of the interproximal restoration margins in relation to the alveolar crest: 2 mm (group A), 1 mm (group B), 0.5 mm (group C), and 0 mm (group D). Fracture strength was measured using a universal testing machine applying a compressive force to the longitudinal tooth axis. Group A had a mean fracture resistance of 859.61 (±267.951) N, group B 1053.9 (±333.985) N, group C 1124.6 (±291.172) N, and group D 780.67 (±183.269) N, with statistical differences between groups. Group C had the highest values for fracture strength compared to the other groups (p < 0.05). The location of the interproximal margins appears to influence the fracture resistance of CAD/CAM endocrown overlays. A distance of 0.5 mm between the interproximal margin and the alveolar crest was associated with increased fracture resistance.


2017 ◽  
Vol 8 (3) ◽  
pp. 83-89
Author(s):  
Johnny Holanda De Gauw ◽  
Lara Maria Melo Costa ◽  
Rodrigo Neves Silva ◽  
Natanael Barbosa Santos ◽  
Maria Dânia Holanda Tenorio

Objective: This study aimed to evaluate the effect of ferrous sulfate (FS) on demineralized and non-demineralized human deciduous teeth. Additionally, it was evaluated the penetration extent of FS and its remineralizing effect on the enamel of deciduous teeth using Polarized Light Microscopy (PLM). Method: The sample comprised 44 human deciduous teeth. The 44 crowns were divided randomly into four groups: group A (FS after demineralization), group B (FS without demineralization), group C (only demineralization), and group D (control group). FS at 0.45 mol/L-1 was used daily (15 days) and demineralization was done by pH cycling (7 days). Then, three longitudinal slices of the crowns were photographed using PLM. The degree of penetration of the lesion or stain was measured in micrometers, as well as the distance between the external enamel surface and the core of lesion. Results: Group A showed a dark stain on the outer surface of enamel larger than the group B. It is suggested, a remineralizing effect when comparing groups, A and C. The mean depth and standard deviation for groups A, B, and C were 4.27µm (±1.49), 3.72 µm (±1.68) and 5.00 µm (±1.84), respectively. No dark stains were observed in group D. Conclusion: FS stained the demineralized and non-demineralized human deciduous teeth. However, dark stains in the non-demineralized teeth were smaller or absent, than in the demineralized teeth. Therefore, FS may have a protective effect against demineralization.


2020 ◽  
Vol 7 (10) ◽  
pp. 2041
Author(s):  
Neha Thilak ◽  
Sundeep K. Hedge ◽  
Sham S. Bhat

Background: The aim of the study is to compare the erosive potential of three different commonly used pediatric syrups on deciduous teeth enamel. The objectives of the study were to assess the endogeneous pH and titratable acidity of mefenamic acid syrup (meftal P), cetrizine syrup (alerid) and multivitamin syrup (zincovit) and to evaluate the microhardness of the enamel after successive immersion cycles in each of the syrups.Methods: 40 non carious deciduous teeth were included for the study The samples were then randomly allocated into 4 groups (10 in each group): Group A- mefenemic acid syrup (meftal P), Group B- cetrizine syrup (alerid), group C- multivitamin syrup (zincovit) and group D- control (distilled water). The samples were then subjected to the immersion cycles in the syrups. Assessment of enamel surface microhardness was done using Vickers hardness tester at 7th day and 14th day. The pH and titrable acidity of the syrups were also assessed. One way analysis of variance (ANOVA) and post hoc tests were used for the statistical analysis.Results: Out of the test groups, group C showed the lowest pH of around 4.2 and exhibited the largest titrable acidity (22.8 ml) compared with 21 ml in group A and 15.5 ml in group B. At the end of 14th day, group A had microhardness of about 293.43.84±6.34, group B had 299.930±6.85, group C had 313.380±6.23 and group D had 334.190±5.51.Conclusions: All the pediatric liquid medications assessed in the study, meftal P, alerid and zincovit showed acidic pH, high titrable acidities and all the syrups showed loss of microhardness after exposure to the syrups for 14 days. Loss of microhardness was highest for meftal P followed by alerid and least for zincovit.


Author(s):  
Marwah Ismael Abdulazeez ◽  
Manhal A. Majeed

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.


2019 ◽  
Vol 9 (1) ◽  
pp. 126
Author(s):  
Mobina Mousavi ◽  
Azadeh Esmaeil Nejad ◽  
Erfan Shamsoddin ◽  
Mohammad Mehdi Golabgiran ◽  
Behzad Houshmand

Background: Zeolite is a microporous aluminosilicate compound which has been successfully used in tissue engineering. The effects of Zeolite on the morphology and functions of pre-osteoblastic MG-63 cells as new bone enhancer material is still unclear. Methods: In this vitro experimental study, MTT and Alizarin red staining test were performed on six groups of MG-63 cells which differed in Zeolite (Z) concentration and the presence or absence of Alloplast extract (A). Group A: 0.1&mu;g/mL Z+A, Group B: 0.1&mu;g/mL Z without A, Group C: 0.2&mu;g/mL Z+A, Group D: 0.2&mu;g/mL Z without A, Group E: 0.3&mu;g/mL Z+A, Group F: 0.3&mu;g/mL Z without A. There were also three control groups as positive control, negative control, and Alloplast control based on each related test. The data were analyzed by SPSS 20 via one-way ANOVA and Welch test. (P&lt;0.05). Results: At 24 hours, results showed that solutions with 0.1&mu;g/mL, 0.2&mu;g/mL, and 0.3&mu;g/mL Zeolite with or without Alloplast had significantly higher proliferation rates than positive control (distilled water) groups without Alloplast (p&lt;0.001). At 72hours time point, the results showed significantly higher proliferation rates in the solutions with 0.1&mu;g/mL, 0.2&mu;g/mL, and 0.3&mu;g/mL Zeolite with or without Alloplast compared to the positive control group without Alloplast (p&lt;0.001). Conclusions: Zeolite can increase proliferation of MG-63 cells without presence of Alloplast; It seems that combination of Zeolite with Alloplast maybe enhancing proliferation and function of MG-63 cells.


2000 ◽  
Vol 24 (4) ◽  
pp. 273-278 ◽  
Author(s):  
Christina Zervou ◽  
Eileen Doherty ◽  
Athanasios Zavras ◽  
George White

The purpose of this study was to evaluate the effect of load on microleakage of pit and fissure sealants. In the first phase of the study load of maximal force (F = 880 N) on central and peripheral enamel was applied. Three groups of ten specimens were tested for microleakage. Group A no application of load, Group B application of load on the central pit of the tooth, and Group application of load on the peripheral enamel 2.5 mm away from the margin of the tooth, at the level of dentinoenamel junction. The results of that study showed significant increase of microleakage on the peripheral sealed enamel, as well as enamel microcracks. So, in the phase II sixty wisdom teeth were sealed with Ultra seal XT plus and load of different magnitude was applied on the peripheral enamel. The specimens were thermocycled for 500 cycles at 5°C and 55°C with a dwell of 30 seconds at each temperature prior to load application. Six groups of ten specimens were tested for microleakage under load. The force was applied at the peripheral enamel, 2.5 mm away from the margin of the tooth, at the level of dentin-enamel junction in cross-section view. Group A: F = 0 N; Group B: F = 300 N; Group C: F = 400 N; Group D: F = 500 N; Group E: F = 600 N; Group F: F = 700 N. Microleakage was scored as distance of dye penetration with 0 = no microleakage and 3 = microleakage to underlying fissure. A linear regression statistics was used with R-squared of 0.31. The groups with load applied (B, C, D, E, F) showed statistically significant results (p&lt;0.05) compared with group A (F = 0 N). Both, the magnitude of the force and tooth morphology may influence the degree of microleakage observed after the placement of sealants.


2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Jozef Mincik ◽  
Daniel Urban ◽  
Silvia Timkova ◽  
Renata Urban

The aim of this study is to compare the effect of various restorative materials on fracture resistance in maxillary premolars. Premolars (n=64) with no restorations or cracks were selected. MOD cavities were prepared considering the buccolingual width to be equal to half of the intercuspal distance. The specimens were randomly divided into 8 groups, 8 specimens each:group Aintact teeth,group Bunfilled cavity,group Ccomposite made by oblique layering technique,group Dcomposite with 2 mm cusp coverage,group Ebulk-filled posterior composite,group Fglass-ionomer,group Gamalgam, andgroup Hcomposite with proximal boxes. The specimens were subjected to an axial compression load with the mean values of fracture resistance in group A: 1289 N, group B: 181.75 N, group C: 445.38 N, group D: 645.88 N, group E: 355.13 N, group F: 352.00 N, group G: 191.38 N, and group H: 572.00 N. There was no significant difference between groups B and G, between C and D, E, and F, and between group D and H. All other measurements were statistically significant. We conclude that composite restoration with cusp coverage is the most ideal nonprosthetic solution for endodontically treated teeth. Cusp coverage increases the fracture resistance compared to the conventional cavity design.


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