scholarly journals Comparison of the Accuracy of Fixture-Level Implant Impression Making with Different Splinting Techniques

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Mehrdad Nateghi ◽  
Ramin Negahdari ◽  
Sahar Molaei ◽  
Ali Barzegar ◽  
Sepideh Bohlouli
Keyword(s):  
Setting Time ◽  
Acrylic Resin ◽  
Study Groups ◽  
Significant Difference ◽  
Group 3 ◽  
The Mean ◽  
Group 2 ◽  
Main Model ◽  
Group 1

Objectives. The impression-taking technique is one of the most critical factors that not only prevents the shrinkage caused by polymerization but also enhances the accuracy of implant impressions. Also, choosing the right time of taking impressions after splinting implants is one of the important criteria that affects the impression-taking technique. Accordingly, the present study aimed to evaluate the accuracy of different splint methods for implant impressions made at different times. Methods. In this in vitro study, a two-piece metallic index was prepared, and the patient’s jaw was simulated by placing self-cured acrylic resin in the lower part of the index. Then, two holes were made in the acrylic resin at a specific distance from each other, and the analogs were placed in these holes. Splinting of impression copings was carried out with autopolymerized acrylic resin (GC Pattern resin LS, GC America Inc., USA), and an open tray impression approach was performed. Thirty-six casts in three groups (n = 12) were fabricated from the acrylic model. After scanning the casts, the impression accuracy was compared between the three study groups by measuring the distance between the outer portions of the scan bodies screw-retained on implant analogs inside the cast using the Exocad software (2015.07 version). Group 1: splinting impression copings with autopolymerized acrylic resin and impression making immediately after the setting time (4 minutes); group 2: splinting and impression procedure after 17 minutes with splint sectioning and reconnection; group 3: splinting and impression procedure after 24 hours with splint sectioning and reconnection. The data were analyzed using SPSS 17 using the Kruskal–Wallis test. Results. The mean distance measured in group 1 was 19.14 ± 0.029 mm, which was significantly lower than the main model. The distances were 19.15 ± 0.039 and 19.159 ± 0.33 mm in groups 2 and 3, respectively. These two groups were not significantly different from the main model. Moreover, the mean distance measured in the three impression techniques was similar. Conclusions. There was no significant difference in the measurements between group 2, group 3, and the main model. Therefore, dentists can make an impression after 17 minutes to reduce chair time.

scholarly journals In vitro assessment of natural extract as irrigant on root dentin microhardness

2020 ◽  
Vol 11 (3) ◽  
pp. 4542-4545
Author(s):  
Sneha Mali ◽  
Abhijeet Phase ◽  
Nootan Mali
Keyword(s):  
Normal Saline ◽  
Hardness Test ◽  
Acrylic Resin ◽  
Natural Extract ◽  
Extract Solution ◽  
Significant Difference ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

To determine the effect of a natural extract of of 2.5% concentration on the of root canal when used as an irrigating solution. This was an in comparative study where and twenty intact single-rooted teeth were selected and with a diamond bur to get an apical-coronal length of 10 mm and were randomly separated into three groups as per the used; Group 1 (control): Irrigation with Normal saline, Group 2: Irrigation with Smear Clear solution, Group 3: Irrigation with 2.5% extract solution. were prepared using Pro Taper Universal Rotary Files with intermittent irrigation with the respective irrigating solution. The teeth were then embedded in acrylic resin and subjected to Vicker's Hardness test, and the data obtained were analyzed using one way ANOVA. When Group 2(51.80±9.80 VHN and 52.66±5.28 VHN) was compared with Group 3(44.98±4.34 VHN and VHN) the values showed a statistically significant difference (p< 0.05).When Group 3 (44.98±4.34 VHN and VHN) was compared with Group 1(65.37±8.80 VHN and 67.74±9.56 VHN), the values did show a statistically significant difference (p> 0.05). Within the limitations of this study, teeth irrigated with normal saline showed the least reduction in followed by irrigation with leaf extract solution and Smear Clear.

scholarly journals Evaluation of Gingival Microleakage in Class II Composite Restorations with Different Lining Techniques: An In Vitro Study

Scientifica ◽  
2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Vedavathi Bore Gowda ◽  
B. V. Sreenivasa Murthy ◽  
Swaroop Hegde ◽  
Swapna Devarasanahalli Venkataramanaswamy ◽  
Veena Suresh Pai ◽  
...  
Keyword(s):  
Study Groups ◽  
Class Ii ◽  
Composite Liner ◽  
Flowable Composite ◽  
Composite Restorations ◽  
Group 4 ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Aim. To compare the microleakage in class II composite restorations without a liner/with resin modified glass ionomer and flowable composite liner.Method. Forty standardized MO cavities were prepared on human permanent mandibular molars extracted for periodontal reasons and then divided into 4 groups of ten specimens. The cavity preparations were etched, rinsed, blot dried, and light cured and Adper Single Bond 2 is applied. Group 1 is restored with Filtek P60 packable composite in 2 mm oblique increments. Group 2 is precure group where 1 mm Filtek Z350 flowable liner is applied and light cured for 20 sec. Group 3 is the same as Group 2, but the liner was cocured with packable composite. In Group 4, 1 mm RMGIC, Fuji Lining LC is applied and cured for 20 sec. All the teeth were restored as in Group 1. The specimens were coated with nail varnish leaving 1 mm around the restoration, subjected to thermocycling, basic fuchsin dye penetration, sectioned mesiodistally, and observed under a stereomicroscope.Results. The mean leakage scores of the individual study groups were Group 1 (33.40), Group 2 (7.85), Group 3 (16.40), and Group 4 (24.35). Group 1 without a liner showed maximum leakage. Flowable composite liner precured was the best.

scholarly journals Comparison of Changes in Number of Hyperreflective Dots After İntravitreal Ranibizumab or Dexamethasone İmplant in Patients with Branch Retinal Vein Occlusion

2021 ◽  
Author(s):  
Aylin Karalezli ◽  
Sema Kaderli ◽  
Ahmet Kaderli ◽  
Cansu Kaya ◽  
Sabahattin Sul
Keyword(s):  
First Year ◽  
Intravitreal Ranibizumab ◽  
Retinal Layers ◽  
Vein Occlusion ◽  
Significant Difference ◽  
Group 3 ◽  
The Mean ◽  
Group 2 ◽  
Group 1

Abstract Purpose: To compare the effect of intravitreal ranibizumab (IVR) or intravitreal dexamethasone implants (IVD) on regression of hyperreflective dots (HRDs) on optical coherence tomography (OCT) B-scan in patients with branch retinal vein occlusion (BRVO). Methods: 37 eyes of 37 patients with cystoid macular edema who received IVR or IVD and followed up for at least 12 months were included in this study. The patients were divided into three groups according to intravitreal treatment. Group 1 consisted of 12 eyes who received only IVD, group 2 consisted of 10 eyes who received only IVR on a pro re nata and group 3 consisted of 15 eyes who received both IVD and IVR. OCT parameters (CMT, number of HRDs, status of external limiting membrane (ELM) and ellipsoid zone (EZ)) and best-corrected visual acuity (BCVA) were compared between the groups over the follow-up time. HRDs were categorized as HRD in inner retinal layers (from the internal limiting membrane to the inner nuclear layer) or HRD in outer retinal layers (from the outer plexiform layer to the outer border of the photoreceptor layer).Results: There was no significant difference between groups in terms of BCVA, CMT, HRDs in the inner and the outer retinal layers at baseline visit. (p˃0.05 for all) Comparing the baseline values in all groups, a significant decrease was observed in CMT in the first year. (For group 1; p=0.013, group 2; p=0.010; group 3, p<0.001) The BCVA was significantly increased after 1 year in all groups. (p=0.001, p=0.006, p<0.001) The mean number of HRDs in inner and outer retinal layers were significantly decreased in group 1 and group 3. (For group 1; p<0.001, p=0.001, for group 3; p<0.001, p<0.001) However, there was no significant difference in terms of the mean number of HRDs in inner and outer retinal layers for group 2. (p=0.134, p=0.477) At the first year, the number of HRDs in inner and outer retinal layers was significantly lower in group 1 and group 3 than group 2. (For inner HRDs; group 1 vs. group 2 p=0.007, group 2 vs. group 3 p<0.001. For outer HRDs group 1 vs. group 2 p<0.001, group 2 vs. group 3 p<0.001.) The BCVA was higher in group 3 than group 2 at 1year. (p=0.048). There was no significant difference in terms of post-treatment CMT and the number of HRDs between group 1 and group3 in posthoc tests (p=0.621, p=0.876, and p=0.632).Conclusion: The reduction in HRDs at 12 months and better BCVA after IVD intimates that the HRDs should be considered as inflammatory markers in the follow-up of CME in BRVO. Thus, IVD injection could be more appropriate for patients with higher HRDs after BRVO.

scholarly journals Shear Bond Strength Comparison between Two Orthodontic Adhesives and Self-Ligating and Conventional Brackets

2007 ◽  
Vol 77 (4) ◽  
pp. 701-706 ◽  
Author(s):  
Rodney G. Northrup ◽  
David W. Berzins ◽  
Thomas Gerard Bradley ◽  
William Schuckit
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Orthodontic Adhesives ◽  
Significant Difference ◽  
Conventional Brackets ◽  
Group 3 ◽  
Group 2 ◽  
Post Hoc ◽  
Group 1

Abstract Objective: To evaluate and compare the shear bond strengths of two adhesives using two types of brackets: a conventional and a self-ligating bracket system. Materials and Methods: Sixty extracted human premolars were collected. The premolars were randomly divided into three groups of 20 teeth. All three groups were direct bonded. Groups 1 and 2 used light-cured adhesive and primer (Transbond XT) with a conventional (Orthos) and a self-ligating bracket (Damon 2), respectively. Group 3 used a light-cured primer (Orthosolo) and a light-cured adhesive (Blūgloo) with a self-ligating bracket (Damon 2). The specimens were stored in distilled water at 37°C for 40 ± 2 hours, after which they were debonded and inspected for Adhesive Remnant Index (ARI) scoring. Results: The mean shear bond strength was 15.2 MPa for group 1, 23.2 MPa for group 2, and 24.8 MPa for group 3. A one-way analysis of variance and post hoc Tukey test showed significant differences in bond strength (P &lt; .001) between group 1 and groups 2 and 3 but no significant difference (P &gt; .05) between groups 2 and 3. A Weibull analysis demonstrated that all three groups provided sufficient bond strength with over 90% survival rate at normal masticatory and orthodontic force levels. A Kruskal-Wallis test showed no significant difference (P &gt; .05) in ARI scores among all three groups. Conclusions: All three groups demonstrated clinically acceptable bond strength. The Damon 2 self-ligating bracket exhibited satisfactory in vitro bond strength with both adhesive systems used.

scholarly journals Effect of Different Finishing and Polishing Methods for Color Stability of the E-Max Dental Ceramics: In vitro Study

2021 ◽  
Vol 14 (4) ◽  
pp. 1508-1513
Author(s):  
Ibraheem F Alshiddi
Keyword(s):  
Surface Brightness ◽  
Color Stability ◽  
Color Measurement ◽  
Control Group ◽  
Group 4 ◽  
Significant Difference ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

In order to assess the influence of finishing and polishing on the surface brightness and color stability of the ceramic veneer, fifty specimens were fabricated with 10 mm diameter and 2 mm thickness using IPS E-Max Ceramic. After glazing, 10 specimens were untouched as control group, and the other 40 specimens were abraded using 125µm diamond bur to create surface roughness. Forty specimens were divided into four groups (n=10), in group 1: specimens were finished using diamond point, in group 2 specimens’ surface was polished with a polishing kit, Group 3: Each specimen surface was polished with the polishing kit as in protocol 2 and was polished a polishing past and group 4 Each specimen was glazed by heating at 621℃ for 3 minutes followed by a temperature increase of 83℃/min up to 918℃ for 30 seconds. Color measurement was performed using spectrophotometer. Color stability data were analyzed using two-way ANOVA and Tukey’s HSD test (α=0.05). For Ra values, paired-samples t-tests were used to analyze the data and compare groups. The change in L and E showed a significant difference among the study groups; (group 1, group 2, group 3 and group 4) with respect to three variables L, a and b. A significant difference was noted when compared each group with the control; however, only group 2 showed a significant difference from group 4; the remaining groups demonstrated similar findings for all three variables. The study displayed a significant impact of the finishing and polishing technique on the surface brightness and color stability of ceramic restoration. However, it was evident that combination of two or three polishing techniques which includes polish kit and glaze enhances the surface finish and adds color stability by alternating the yellow – blue axis (increase in b) and red- green axis (decrease in a).

scholarly journals Effects of eliminating tension by means of epineural stitches: a comparative electrophysiological and histomorphometrical study using different suture techniques in an animal model

2011 ◽  
Vol 69 (2b) ◽  
pp. 365-370 ◽  
Author(s):  
J Bustamante ◽  
M Socolovsky ◽  
R S Martins ◽  
J Emmerich ◽  
M G Pennini ◽  
...  
Keyword(s):  
Test Results ◽  
Motor Action ◽  
Nerve Suture ◽  
Group 4 ◽  
Significant Difference ◽  
Group 3 ◽  
The Mean ◽  
Group 2 ◽  
Human Nerve ◽  
Group 1

Epineural stitches are a means to avoid tension in a nerve suture. We evaluate this technique, relative to interposed grafts and simple neurorraphy, in a rat model. METHOD: Twenty rats were allocated to four groups. For Group 1, sectioning of the sciatic nerve was performed, a segment 4 mm long discarded, and epineural suture with distal anchoring stitches were placed resulting in slight tension neurorraphy. For Group 2, a simple neurorraphy was performed. For Group 3, a 4 mm long graft was employed and Group 4 served as control. Ninety days after, reoperation, latency of motor action potentials recording and axonal counts were performed. Inter-group comparison was done by means of ANOVA and the non-parametric Kruskal-Wallis test. RESULTS: The mean motor latency for the simple suture (2.27±0.77 ms) was lower than for the other two surgical groups, but lower than among controls (1.69±0.56 ms). Similar values were founding in both group 1 (2.66±0.71 ms) and group 3 (2.64±0.6 ms). When fibers diameters were compared a significant difference was identified between groups 2 and 3 (p=0.048). CONCLUSION: Good results can be obtained when suturing a nerve employ with epineural anchoring stitches. However, more studies are needed before extrapolating results to human nerve sutures.

scholarly journals An Evaluation of Shear Bond Strength of Self-Etch Adhesive on Pre-etched Enamel: An in vitro Study

2013 ◽  
Vol 14 (6) ◽  
pp. 1036-1038
Author(s):  
Abdul Mujeeb ◽  
Bhadra Rao ◽  
Satti Narayana Reddy ◽  
Kanchan Mehta ◽  
G Saritha
Keyword(s):  
Statistical Analysis ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Occlusal Surfaces ◽  
Group 3 ◽  
The Mean ◽  
Group 2 ◽  
Self Etch ◽  
Group 1

ABSTRACT Aim To determine the shear bond strength of self-etch adhesive G-bond on pre-etched enamel. Materials and methods Thirty caries free human mandibular premolars extracted for orthodontic purpose were used for the study. Occlusal surfaces of all the teeth were flattened with diamond bur and a silicon carbide paper was used for surface smoothening. The thirty samples were randomly grouped into three groups. Three different etch systems were used for the composite build up: group 1 (G-bond self-etch adhesive system), group 2 (G-bond) and group 3 (Adper single bond). Light cured was applied for 10 seconds with a LED unit for composite buildup on the occlusal surface of each tooth with 8 millimeters (mm) in diameter and 3 mm in thickness. The specimens in each group were tested in shear mode using a knife-edge testing apparatus in a universal testing machine across head speed of 1 mm/ minute. Shear bond strength values in Mpa were calculated from the peak load at failure divided by the specimen surface area. The mean shear bond strength of all the groups were calculated and statistical analysis was carried out using one-way Analysis of Variance (ANOVA). Results The mean bond strength of group 1 is 15.5 Mpa, group 2 is 19.5 Mpa and group 3 is 20.1 Mpa. Statistical analysis was carried out between the groups using one-way ANOVA. Group 1 showed statistically significant lower bond strength when compared to groups 2 and 3. No statistical significant difference between groups 2 and 3 (p < 0.05). Conclusion Self-etch adhesive G-bond showed increase in shear bond strength on pre-etched enamel. How to cite this article Rao B, Reddy SN, Mujeeb A, Mehta K, Saritha G. An Evaluation of Shear Bond Strength of Self-Etch Adhesive on Pre-etched Enamel: An In vitro Study. J Contemp Dent Pract 2013;14(6):1036-1038.

scholarly journals Fracture Resistance of a Bulk-Fill and a Conventional Composite and a Combination of Both for Coronal Restoration of Severely Damaged Primary Anterior Teeth

2019 ◽  
Author(s):  
Shahram Mosharrafian ◽  
Maryam Shafizadeh ◽  
Zeinab Sharifi
Keyword(s):  
Fracture Resistance ◽  
Treatment Time ◽  
Testing Machine ◽  
Anterior Teeth ◽  
Significant Difference ◽  
Group 3 ◽  
The Mean ◽  
Group 2 ◽  
One Way Anova

Objectives: This study aimed to compare the fracture resistance of a bulk-fill and a conventional composite and a combination of both for coronal restoration of severely damaged primary anterior teeth. Materials and Methods: In this in vitro experimental study, 45 primary anterior teeth were randomly divided into three groups. After root canal preparation, the canals were filled with Metapex paste such that after the application of 1 mm of light-cure liner, 3 mm of the coronal third of the canal remained empty for composite post fabrication. Filtek Z250 conventional composite was used in group 1, Sonic-Fill bulk-fill composite was used in group 2 and Sonic-Fill with one layer of Filtek Z250 as the veneering were used in group 3. Adper Single Bond 2 was used in all groups. The teeth were thermocycled, and fracture resistance was measured by a universal testing machine. The mode of fracture was categorized as repairable or irreparable. Data were analyzed using one-way ANOVA. Results: The mean fracture resistance was 307.00±74.72, 323.31±84.28 and 333.30±63.96 N in groups 1 to 3, respectively (P=0.55). The mean fracture strength was 14.53±2.98, 15.08±2.82 and 15.26±3.02 MPa in groups 1 to 3, respectively (P=0.77). The frequency of repairable mode of failure was 80% for the conventional, 73.6% for the bulk-fill and 80% for the bulk-fill plus conventional group, with no significant difference (P>0.05). Conclusions: Bulk-fill composites can be used for coronal reconstruction of severely damaged primary anterior teeth similar to conventional composites to decrease the treatment time in pediatric patients.

scholarly journals In Vitro Microbiological Analysis of Bacterial Seal at the Implant-Abutment Interface Using Two Morse Taper Implant Models

2014 ◽  
Vol 25 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Deceles Cristina Costa Alves ◽  
Paulo Sérgio Perri de Carvalho ◽  
Elizabeth Ferreira Martinez
Keyword(s):  
Brain Heart Infusion ◽  
The Other ◽  
Microbiological Analysis ◽  
Torque Wrench ◽  
Significant Difference ◽  
Implant Abutment ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

The objective of this study was to evaluate the bacterial seal at the implant-abutment interface using two morse taper implant models, by means of an in vitro microbiological analysis. For that were used 15 implants with mini-abutments tightened by friction, no screws (Group 1); and 30 implants with screw-tightened abutments, of which 15 received 20 N.cm of closing torque (Group 2) and the other 15 received 30 N.cm (Group 3). Microbiological analysis was carried out using colonies of Escherichia coli transported directly from a culture dish to the prosthetic component. Friction implants (Group 1) were activated by tapping and a torque wrench was used for screw-tightened implants (Groups 2 and 3). Each abutment/implant set was immersed in test tubes containing 5 mL of brain-heart infusion broth and incubated at 37 °C for 14 days, observed daily for the presence of contamination. A statistically significant difference was observed regarding the number of contaminated implants. There was greater contamination in Group 2 implants (p<0.05), with no statistically significant difference between the other groups (Group 1 = 20% and Group 3 = 0%). It was concluded that there was no significant difference in in vitro bacterial sealing between implants with mini-abutments tightened by friction without screws and implants with screw-tightened abutments with 30 N.cm of closing torque. The difference in closing torque altered the in vitro sealing ability of the tested abutments, with a greater contamination for components that received a closing torque of 20 N.cm.

scholarly journals The effects of local nitroglycerin on the surgical delay procedure in prefabricated flaps by vascular implant in rats

2012 ◽  
Vol 27 (12) ◽  
pp. 905-911 ◽  
Author(s):  
Jairo Zacchê de Sá ◽  
José Lamartine de Andrade Aguiar ◽  
Adriana Ferreira Cruz ◽  
Alexandre Ricardo Pereira Schuler ◽  
José Ricardo Alves de Lima ◽  
...  
Keyword(s):  
Wistar Rats ◽  
Delay Procedure ◽  
Surgical Delay ◽  
Group 4 ◽  
Significant Difference ◽  
Group 3 ◽  
The Mean ◽  
Group 2 ◽  
Prefabricated Flap ◽  
Group 1

PURPOSE: To evaluate the effect of local nitroglycerin on the viable area of a prefabricated flap for vascular implant in rats, and to investigate the surgical delay procedure. METHODS: A femoral pedicle was implanted under the skin of the abdominal wall in forty Wistar rats. The animals were divided into four groups of ten: group 1 - without surgical delay procedure and local nitroglycerin; group 2 - with surgical delay procedure, but without local nitroglycerin; group 3 - without surgical delay procedure, but with local nitroglycerin; and group 4 - with simultaneous surgical delay procedure and local nitroglycerin. The percentages of the viable areas, in relation to the total flap, were calculated using AutoCAD R 14. RESULTS: The mean percentage value of the viable area was 8.9% in the group 1. 49.4% in the group 2; 8.4% in the group 3 and 1.1% in the group 4. There was significant difference between groups 1 and 2 (p=0.005), 1 and 4 (p=0.024), 2 and 3 (p=0.003), 2 and 4 (p=0.001). These results support the hypothesis that the closure of the arterial venous channels is responsible for the phenomenon of surgical delay procedure. CONCLUSION: Local nitroglycerin did not cause an increase in the prefabricated viable flap area by vascular implantation and decreased the viable flap area that underwent delay procedures.

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