Effect of Different Implant-Abutment Connection Materials on the Fracture Resistance of Zirconia Abutments

2020 ◽  
Vol 46 (2) ◽  
pp. 88-92 ◽  
Author(s):  
Mohammed AlAmar ◽  
Fawaz Alqahtani

The aim of the present in vitro study was to assess the modes of failures under static load among titanium (Ti) and 1- and 2-piece zirconia abutments. The 1- and 2-piece zirconia abutment specimens were fabricated from prescanned Ti abutments. Twenty-one implant abutments and 21 implant replicas were equally divided into 3 groups as follows: (a) Group 1 (Titanium group); (b) Group 2 (1-piece zirconia abutment group); and (c) Group 3: 2-piece zirconia abutment group). A 250 000-cycle linear fatigue load ranging between 10 N and 210 N was applied to all specimens using an all-electric dynamic test instrument. The specimens were loaded until they fractured. In all groups, assessment of mode of fracture was done on visual assessment by a trained and calibrated investigator. Prior sample-size estimation was performed; and sample distribution was assessed using the Kolmogorov and Shapiro tests. Screw fracture (n = 7) and abutment bending at the apical part (n = 7) occurred in the Ti group. In the 1-piece zirconia group, screw and abutment fractures occurred in 7 and 7 cases, respectively. In the 2-piece zirconia screw fracture (n = 7) above the Ti zirconia junction (transgingival segment) and abutment fracture (n = 7) were determined as the failure modes. In vitro, the 1-piece zirconia abutments are more fracture resistant than titanium and 2-piece zirconia abutments. From a clinical perspective, further studies are needed to determine the minimum static load value required to induce fracture of the 1- and 2-piece zirconia abutments.

2020 ◽  
Vol 14 (01) ◽  
pp. 157-160 ◽  
Author(s):  
Fawaz Alqahtani ◽  
Mohammed AlAmar

Abstract Objectives The objective was to assess modes of failures under static load (SL) among titanium (Ti) and one- and two-piece zirconia abutment (ZA) in vitro. Materials and Methods The Ti abutments were digitally scanned for the fabrication of the one- and two-piece zirconia abutment specimens. This was done to standardize the design of the one-piece abutment and make it the blueprint of the Ti abutment. Twenty-one implant abutments and 21 implant replicas were categorized into three groups as follows: group 1 (Titanium group), group 2 (one-piece ZA group), and group 3 (two-piece ZA group). A 250K-cycle, linear fatigue-load, reaching 10 to 210 Newton (N), was put on all specimens using an all-electric dynamic test instrument and the specimens were loaded until fracture. Statistical Analysis Assessment of mode of fracture among the groups was done visually. Significance was based below 0.05. Results Screw fracture (n = 7) and abutment bending at the apical part (n = 7) occurred in the Ti group. In the one-piece zirconia group, screw and abutment fractures occurred in seven and seven cases, respectively. In the two-piece zirconia group, screw fracture (n = 7) above the Ti zirconia junction (transgingival segment) and abutment fracture (n = 7) were determined as the failure modes. Conclusion In conclusion, all abutments underwent failures under SL in vitro; and the mode of failure modes varied among the different abutment designs used.


Author(s):  
Rathika Rai ◽  
M. A. Easwaran ◽  
K. T. Dhivya

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


Author(s):  
Teresa Al Haddad ◽  
Elie Khoury ◽  
Nada Farhat Mchayleh

Abstract Objectives The aim of the present in vitro study is to compare the remineralization brushing effect of three toothpastes and Aloe vera (AV) gel. Materials and Methods Forty sound extracted teeth were placed in a demineralizing solution for 4 days and randomly assigned to four groups: group A: 1,450-ppm fluoride toothpaste; group B: AV nonfluoridated toothpaste; group C: AV 1,000-ppm fluoridated toothpaste; and group D: AV gel. A 3-minute pH cycling was performed twice a day for each group for 12 days. Specimens were analyzed before and after by scanning electron microscope—energy dispersive X-ray. Statistical analysis The outcomes were analyzed by Kolmogorov–Smirnov’s tests, repeated-measures analyses of variance followed by univariate analyses, and Bonferroni’s multiple comparisons tests to compare the calcium-to-phosphorus (Ca:P) ratio within time among toothpaste groups. Results Following remineralization, the Ca:P ratio increased in all groups. The difference of the Ca:P ratio was not significant between groups C, D, and A. The mean ratio was significantly lower in group B (p-value = 0.026). Conclusions The AV gel demonstrated a remineralization capacity equal to that of the 1,450-ppm fluoride toothpaste. In contrast, fluoride-free AV toothpaste showed a lower remineralization efficiency. Further studies are required to understand its mechanism.


2019 ◽  
Vol 3 (9) ◽  
pp. 283-289
Author(s):  
Shuchi Sukul ◽  
Goldy Rathee ◽  
Parimal Anand ◽  
Sakshi Kataria ◽  
Pratibha Taneja

OBJECTIVES: The present research was conducted to assess incidences of root microcracks caused by hand and rotary file system at different lengths MATERIAL AND METHODS: This in-vitro study was undertaken to assess incidence of root microcracks caused by hand and rotary file system at different lengths In total, 100 the mandibular premolar with straight roots determined with intact, fully formed apices were taken. Samples were randomly distributed into 5 groups based on the file system used: a) Group A: Control, b) Group B: Reciproc, c) Group C: WaveOne, d) Group D: One Shape and e) Group E: ProTaper. Pearson Chi-square test was used to determine the differences between groups. The dentinal defects were expressed as percentage of samples with microcracks in each group. Level of statistical significance was set at p-value less than 0.05. RESULTS: The chi square test was used to compare the Distribution of the number of teeth in which cracks were observed on the horizontal sections. It was found to be significant with group ProTaper showing maximum cracks at 3,6,9 mm level as compared to other file systemCONCLUSION: Nickel-titanium instruments causes cracks on the apical root surface or in the root canal wall. ProTaper causes maximum dentinal cracks as compared to other file systems


2017 ◽  
Vol 9 (2) ◽  
pp. 4-10
Author(s):  
Krishna Prasada L ◽  
Jyothsna S Jathanna ◽  
Naveen Kumar ◽  
Ramya M.K ◽  
Elizabeth Issac

BACKGROUND: To determine the effectiveness of three polishing systems on three different composite materials by evaluating surface roughness using a Profilometer and Scanning electron microscope. METHODOLOGY: A total of Sixty-three resin composite disks were prepared in rectangular acrylic mould of 8×2mm dimension, with 4mm thickness. Specimens were made of light activated resin composite Filtek Z-250-XT, Tetric-N-Ceram bulkfill, Ceram X Duo. The sixty-three samples were divided into three groups of twenty-one samples each i.e. Group A (Filtek Z-250-XT), Group B (TetricN-Ceram bulkfill) and Group C (Ceram-X-Duo).Out of 21 samples of each of the material, 7 specimens were polished with multi enhance polishing agents, 7 specimens were polished with super snap polishing agents and 7 specimens were polished with sof-lexdiscs.Surface roughness of each sample after polishingwasevaluatedusingProfilometer and Scanning electron microscope. RESULTS: One-way anova and kruskalwallis test was used for statistical analysis. Ceram-X-Duo gave least roughness average value with Super snap polishing system when compared to multi enhance and sof-lex polishing system. CONCLUSION: Super snap polishing system is a better polishing system than multi enhance and soflex and Ceram-X-Duo composite material offers better polishability compared to Filtek Z-250-XT and Tetric-N-Ceram bulk fill.


2019 ◽  
Vol 17 (1) ◽  
pp. 228080001881601
Author(s):  
Filiberto Mastrangelo ◽  
Isabella Perraro ◽  
Sabrina Mattia ◽  
Giuseppe Troiano ◽  
Khrystyna Zhurakivska ◽  
...  

Introduction: The technique of sealing is a widely accepted procedure for prevention of caries. The aim of our in vitro study was to compare the effect of two different curing units (traditional LED source and innovative laser diode lamp) on the integrity of fissure sealant material and its interface with tooth enamel. Materials and methods: Sixty healthy third molars were randomly assigned to two groups. In group A were teeth intended for polymerization by LED B lamp, and group B comprised teeth to be polymerized by an innovative laser diode. Both groups were treated with the traditional sealing technique, subjected to a metallization process, and analyzed by scanning electron microscope. Results: Micro-gaps between the sealant and the enamel were found in specimens in both A (43%) and B (40%) groups ( p=0.793), and sealant shrinkage was seen. Significant differences between the groups emerged in the percentage of perimetric micro-erosion sites (80% vs. 100%, p=0.010) and the presence of holes and micro-bubbles on the sealant surface (21% vs. 63%, p=0.001). Conclusions: Although macroscopic clinical polymerization occurred with both instruments, the microscopic evaluation showed significant differences between the studied groups in terms of perimetric micro-erosion sites and micro-bubbles, which were higher in laser-cured samples.


Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1833 ◽  
Author(s):  
Rafael Delgado-Ruiz ◽  
Ana Nicolas Silvente ◽  
Georgios Romanos

Implant connections must resist surgical and prosthetic procedures without deformation. This study evaluated the deformation of different internal connections (IC) of narrow dental implants (NDI) after their insertion in artificial dense bone. Thirty NDI, with different IC geometries, Group A (internal hexagon), Group B (tri-channeled), and Group C (four-channeled), with the same length and similar narrow diameters, were inserted in type II density bone blocks. Drilling protocols for dense bone from each implant manufacturer were followed. The Insertion torque (IT), connection length, vertex angles, and wall deformations were analyzed before and after the insertion of the implants. ANOVA (Analysis of Variance) and Tukey post-test were used for statistical comparisons. IT values were higher for Group A, surface damage, and titanium particles were observed in the IC in all the groups. Angle deformations between 5 and 70 degrees were present in all the groups, and the walls of Group B connection were the most affected by deformations (p < 0.05). Within the limitations of this experiment, it can be concluded that narrow diameter implants will suffer deformation of the implant connection and will also experience surface damage and titanium particle release when inserted in type II bone density.


Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3056
Author(s):  
Hadas Heller ◽  
Adi Arieli ◽  
Ilan Beitlitum ◽  
Raphael Pilo ◽  
Shifra Levartovsky

The static and dynamic load-bearing capacities and failure modes of zirconia crowns screwed to multi-unit abutments (MUAs) with and without a titanium base (T-base) were determined. Thirty-six monolithic zirconia crowns screwed to straight MUAs torqued to laboratory analogs (30 Ncm) were assigned to two groups (n = 18). In group A, the zirconia crowns were screwed directly to the MUAs; in group B, the zirconia crowns were cemented to the T-base and screwed to the MUAs. All specimens were aged in 100% humidity (37 °C) for one month and subjected to thermocycling (20,000 cycles). Afterwards, the specimens underwent static and dynamic loading tests following ISO 14801. The failure modes were evaluated by stereomicroscopy (20×). There was an unequivocally similar trend in the S-N plots of both specimen groups. The load at which the specimens survived 5,000,000 cycles was 250 N for both groups. Group A failed mainly within the metal, and zirconia failure occurred only at a high loading force. Group B exhibited failure within the metal mostly in conjunction with adhesive failure between the zirconia and T-base. Zirconia restoration screwed directly to an MUA is a viable option, but further studies with larger sample sizes are warranted.


2020 ◽  
Vol 54 (3) ◽  
pp. 233-239
Author(s):  
Ashish Kumar Barik ◽  
Ritu Duggal

Introduction: Fluoride is known to reduce demineralization and enhance remineralization which is desirable around orthodontic brackets. Material and methods: This study was carried out to determine the rate of fluoride release, fluoride content of enamel, and surface alteration of enamel from orthodontic bonding agents. Thirty extracted maxillary first premolars were divided into 2 groups of 15 teeth each. Group A—teeth were bonded with a chemically cured orthodontic bonding agent containing fluoride (Rely-a-Bond, Reliance, Itasca) and group B—teeth were bonded with a light-cured orthodontic bonding agent containing fluoride (Light Bond Reliance, Itasca). All individual sample teeth were used to estimate fluoride release and fluoride content of enamel. The same samples were also used to evaluate enamel surface alterations. The rate of fluoride release from the above 2 orthodontic bonding agents were measured in artificial saliva on day 1, 2, 3, 4, 5, 6, 7, 14, 30, 60, and 90. The fluoride content of the enamel was evaluated on day “0” and day “90” of bonding. The samples were also evaluated for the surface changes in enamel using scanning electron microscope (SEM). Results: The results showed that (a) chemically cured and light-cured bonding agent showed a dramatic decrease in the concentration of fluoride release from day “1” to day “2,” (b) the concentration of fluoride release kept decreasing from day “1” to day “90” of measurement in both the groups, and (c) SEM of the bracket margins bonded with chemically cured bonding agent and light-cured bonding agent revealed particle depositions of irregular shape and size on day “90.” Conclusion: Light-cured bonding agent (Light Bond) released higher concentration of fluoride as compared to chemically cured bonding agent (Rely-a-Bond). Light-cured bonding agent (Light Bond) showed higher increase in fluoride content of enamel than chemically cured bonding agent (Rely-a-Bond).


Author(s):  
Peng Wang ◽  
Xiao-Xia Hu ◽  
Ying-hui Li ◽  
Nan-Yong Gao ◽  
Guo-quan Chen ◽  
...  

This study was to evaluate the effect of resveratrol on the pharmacokinetics of ticagrelor in rats and the metabolism of ticagrelor in human CYP3A4 and liver microsomes. Eighteen Sprague-Dawley rats were randomly divided into three groups: group A (control group), group B (50mg/kg resveratrol), and group C (150mg/kg resveratrol ). After 30 minutes administration of resveratrol, a single dose of ticagrelor (18mg/kg) was administered orally. The vitro experiment was performed to examine the influence of resveratrol on ticagrelor metabolism in CYP3A4*1, human, and rat liver microsomes. Serial biological samples were assayed by validated UHPLC-MS/MS methods. In vivo study, the AUC and Cmax of ticagrelor in group B and C appeared to be significantly higher than the control group, while Vz/F and CLz/F of ticagrelor in group B and C were significantly decreased. In vitro study, resveratrol exhibited an inhibitory effect on CYP3A4*1, human and rat liver microsomes. The IC50 values of resveratrol were 56.75μM,69.07μM and 14.22μM, respectively. Our results indicated that resveratrol had a inhibitory effect on the metabolism of ticagrelor in vitro and vivo. It should be paid more attention to the clinical combination of resveratrol with ticagrelor and ticagrelor plasma concentration should be monitored to avoid the occurrence of adverse reaction.


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