scholarly journals Photoelastic analysis of stress generated by Connecticut Intrusion Arch (CIA)

2017 ◽  
Vol 22 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Alessandro Schwertner ◽  
Renato Rodrigues de Almeida ◽  
Alcides Gonini Jr ◽  
Marcio Rodrigues de Almeida

ABSTRACT Objective: The present in vitro study evaluated, by means of the photoelastic technique, the effects generated by the Connecticut Intrusion Arch (CIA), with a 90o bend on the distal surface of molar tubes and using the 4 x 2 appliance on the anterior and posterior regions of the upper dental arch. Methods: Five models were manufactured, in which two different clinical situations were correlated: 1) use of intrusion arch not cinched back and transpalatal bar for anchorage (Group 1); 2) use of intrusion arch cinched back and transpalatal bar for anchorage (Group 2). Stress generated in the apical and middle regions of tooth roots of maxillary anterior teeth and maxillary first molars was evaluated. Results: Taking a reference value of 1.0 MPa = 100%, qualitative descriptive analysis was performed, which showed uniformity between stress values in the apical region of anterior teeth of both groups (G1 and G2). In the posterior region, for models with the arch cinched back (G2), stress remained within 100%. As for G1 models (with the arch not cinched back), variations in the mesial surface of first molars were observed, with an increase of 20% in the generated stress. The apical region did not undergo any changes, while in the distal region of molars there was a decrease of 20% in stress. Conclusion: Laboratory results revealed differences in stress between Groups 1 and 2 in the molar region, thereby indicating that there was a tendency towards mesial root tipping of first molars when the distal end of the CIA was not cinched back.

Author(s):  
Anshula Deshpande ◽  
Chirag Macwan ◽  
Steffi Dhillon ◽  
Medha Wadhwa ◽  
Neelam Joshi ◽  
...  

Introduction: Microleakage is an important property that has been used in assessing the success of any restorative material used in restoring a tooth. Immediate application of a surface coating agent is suggested to protect glass ionomer cement against moisture contamination and dehydration during early setting. Aim: To compare marginal microleakage of two different Glass Ionomer Cement (GIC)- Conventional GIC and Resin Modified GIC in primary anterior teeth using three surface coating materials. Materials and Methods: An in vitro study was conducted between January 2014 to October 2017 on freshly extracted 40 anterior primary teeth which were randomly assigned into two main groups (Fuji II GIC and Fuji II LC GIC) with four subgroups (control-no surface coating, A=GC Fují Varnish II, B=GC G-Coat Plus, C=Icon). A standardised Class V cavity preparation was prepared on the labial surface of each tooth. Specimens were coated with two layers of nail varnish, leaving a 1 mm window around the cavity margins and placed in a solution of Methylene blue Dye for 24 hour at 37°C. The teeth were sectioned longitudinally in a buccolingual direction of the restorations and evaluated under stereomicroscope to check extent of dye penetration. The results were analysed by ANOVA and Tukey’s post-hoc test (p≤0.05). Results: It was found that maximum microleakage was seen in group 1 (Fuji II GIC) as compared to group 2 (Fuji II LC GIC) and it was non-significant (p=0.53). Ascending order for mean microleakage for Group 1 was as follows: Control >GC Fuji Varnish >Icon DMG >GC G-Coat and for Group 2: Control >GC Fuji Varnish >Icon DMG >GC G-Coat. Icon when compared with Gc coat and Varnish also showed non-significant (p=0.137) difference in Group 2. Conclusion: All three different surface coatings can seal glass ionomer restorations. The GC G-Coat Plus has the least microleakage on Resin-Modified GIC (RMGIC) compared to the other surface coatings. This would aid the clinicians to make appropriate decision regarding the choice of material to be used for restoration and coating in anterior primary teeth.


2007 ◽  
Vol 18 (1) ◽  
pp. 20-23 ◽  
Author(s):  
João Vicente Baroni Barbizam ◽  
Matheus Souza ◽  
Doglas Cecchin ◽  
Jakob Dabbel

The purpose of this in vitro study was to evaluate the ability of a silicon-based root canal sealer, compared to zinc oxide and eugenol and an epoxy resin-based sealers, for filling of simulated lateral canals. Thirty extracted single-rooted human teeth were selected, conventional access was made and the working length was established 1 mm from the apical foramen. Three simulated lateral canals, one in each root third (coronal, middle and apical) were prepared in both the mesial and distal surfaces of each tooth using a size 15 reamer adapted to a low-speed handpiece. Each root canal was instrumented using ProTaper rotary files up to file F3 at the working length, and then irrigated with 2.5% NaOCl followed by EDTA. The teeth were assigned to 3 groups (n=10), according to the root canal sealer: Roeko Seal (Group 1), Sealer 26 (group 2) and Grossman's sealer (Group 3). Gutta-percha cold lateral condensation technique was performed in all groups. Postoperative radiographs were taken and the images were projected for evaluation of the quality of lateral canal filling. Data were submitted to statistical analysis by Kruskal Wallis test at 5% significance level. The results showed that Grossman's sealer filled a larger number of lateral canals than Roeko Seal (p<0.05) and Sealer 26 (p<0.01). It may be concluded that Roeko Seal silicone-based root canal sealer was not as effective as the Grossman's sealer for filling of simulated lateral canals. The lateral canals localized in the apical third of the root were more difficult to be filled.


2018 ◽  
Vol 12 (1) ◽  
pp. 638-646 ◽  
Author(s):  
Massimo Amato ◽  
Alfredo Iandolo ◽  
Giuseppe Pantaleo ◽  
Dina Abtellatif ◽  
Michele Simeone ◽  
...  

Aim: The aim of this study was to evaluate the efficacy of the IG-file, a new instrument designed for apical diameter gauging. Materials and Methods: After shaping with F1 Universal Protaper, 60 roots were randomly divided into two groups and assigned to two operators, One Expert in Endodontics (EO) and One Unexpert (UO). In each sample, after canal curvatures have been detected, the apical diameters were measured with the IG-file and the K-NiTi. The results were compared with the reference value obtained by retrograde apical gauging. The data were statistically analyzed. Results: Among 60 samples, 10% of errors were recorded when the IG-files were used; in the K-NiTi group the incorrect measurements were 70%. In both groups (expert and unexpert) the IG-file measurements were more accurate than the K-NiTi (90 vs 33 and 90 vs 26,7). The differences were statistically significant. In curved canals, the difference between measurement rates performed with both instruments was statistically significant (85,7% IG-file vs 28,6% K-NiTi) as well as for the samples without curvatures (92,3% IG file vs 30,8% NiTi file). In root canals without curvatures overestimation errors in K-NiTi file group are more frequent than underestimation errors. This difference was statistically significant. Conclusion: A proper gauging of the apical diameter has a key role in endodontic therapy; an incorrect measurement can lead to clinical failures. This “in vitro” study highlights that IG-file improves measurement accuracy independently from clinician experience. Furthermore, in curved canals, the IG-file is more accurate than K-NiTi.


Author(s):  
Deebah Choudhary

Aim: The aim of this study was to evaluate the canal cleaning efficacy of these three file systems using scanning electron microscopy. Place and Duration of Study: The study was conducted in the Department of Conservative dentistry and Endodontics, Institute of Dental Sciences Sehora, between October 2020 and December 2020. Materials and Methods: Access cavity preparation was performed on sixty extracted human mandibular premolar teeth and working length was determined. The samples were randomly divided into three groups (n=20) depending upon the file system used i.e. Group 1 (Reciproc Blue), Group 2 (Waveone Gold) and Group 3 (F360). Samples were split into two halves by creating longitudinal grooves on the buccal and lingual surfaces. The samples were sputter-coated with gold and examined under scanning electron microscope at 5000X. The dentinal wall of root canal at coronal, middle and apical thirds of each sample were evaluated for the presence of determining the canal cleanliness and then analyzed using a five-score index. Results: The results of this study revealed that Group 1 (Reciproc Blue) exhibited better cleaning efficacy than samples of Group 2 (WaveOne Gold) and Group 3 (F360) at different locations in the canal i.e. coronal, middle and apical. The mean debris present was highest in coronal area for both group 2 and group 3 i.e. 2.1 and least was seen in apical area of group 1 i.e. 0.3. (p<0.05) Conclusion: Reciproc Blue single-file showed highest cleaning efficacy followed by Waveone Gold and F360. Reciproc file also showed effective cleaning in the apical third of the canal.


2002 ◽  
Vol 3 (2) ◽  
pp. 23-30 ◽  
Author(s):  
Güliz Görgül ◽  
A. Cemal Tinaz ◽  
Tayfun Alaçam ◽  
Bağdagül H. Kivanç ◽  
Özgür Uzun

Abstract The aim of this in vitro study was to evaluate the apical and coronal microleakage of a packable composite material compacted by either hand or ultrasonic condensers when placed in post spaces. Fortytwo extracted anterior teeth were used. After conventional obturation of the root canals, parallel post spaces 5 mm in depth and 2 mm in diameter were prepared using Gates Glidden and diamond burs. A primer and a dentin bonding agent (Prime & Bond NT) was applied to the etched surface for 30 seconds and light polymerized for 40 seconds. Surefil packable composite resin was inserted in four equal increments and each polymerized for 40 seconds. Half of the specimens were compacted with an ultrasonic tip and the other half with a mechanical hand compactor. After immersion in the dye, the teeth were sectioned longitudinally and dye penetration was evaluated using a stereomicroscope and microleakage recorded in mm. A One-Way Analysis of Variance indicated the two condensing methods were not statistically different (p>0.05). When microleakage was compared within groups, there was also no statistical difference between coronal or apical microleakage (p>0.05). In an in vitro environment, ultrasonic condensers do not offer any advantage over hand condensers. Both the coronal and apical portions of the root had microleakage indicating that regardless of the condensation method and the use of a packable composite, there is still microleakage that could potentially create further clinical problems. Citation Görgül G, Alaçam T, Kivanç BH, et. al. Microleakage of Packable Composites Used in Post Spaces Condensed Using Different Methods. J Contemp Dent Pract 2002 May;(3)2: 023-030.


2020 ◽  
Vol 54 (4) ◽  
pp. 311-320
Author(s):  
Neeraj E Kolge ◽  
Vivek J Patni ◽  
Girish Karandikar ◽  
Ravindranath VK ◽  
Prateek Daga ◽  
...  

Aims & Objectives: The aim of the study was to evaluate and compare dimensional accuracy, surface characteristics and load deflection attributes of SS wires sourced from six different commercial houses. Materials & Methods: 0.019” x 0.025” SS wire samples were divided into 6 groups and evaluated and compared for the aforementioned properties. Dimensional accuracy, surface roughness, frictional resistance, load deflection rate and ultimate tensile strength were evaluated and compared. Results: Dimensional accuracy did not vary significantly. Surface Profilometry proved 3M Unitek (Group 1) to be the wire with least irregularities. According to SEM, Modern Orthodontics (Group 6) and 3M Unitek (Group 1) in terms of ‘Sa’ and ‘Sq’ respectively had the smoothest surface finish. SS wires sourced from G&H Orthodontics (Group 2) exhibited least frictional resistance. Load deflection rates varied for all the groups for all three parameters under the study. UTS was best for SS wires sourced from Rabbit Force Orthodontics (Group 5). Conclusion: No wire from a single commercial house excels in all the parameters that were evaluated, each one having its aces and minuses.


Author(s):  
A. Anushree ◽  
Ashutosh Shetty ◽  
Crystal Runa Soans ◽  
M. N. Kuttappa ◽  
Akhil Shetty ◽  
...  

Abstract Aim: The study aimed to evaluate the shear bond strength (SBS) of metal brackets and adhesive properties of bonded irradiated and non-irradiated teeth. Methods: Sixty-six extracted premolar samples were randomly divided into three groups—(a) Control group consisting of 22 non-irradiated, non-aged teeth (Group 1), (b) 22 non-irradiated, aged samples (Group 2) and (c) 22 irradiated, aged samples (Group 3). Irradiation was done using gamma irradiation with a fractionated dose of 60 Gy for 5 consecutive days per week over 6 weeks. Metal brackets were bonded on all samples with light cure adhesive and subjected to SBS test using universal testing machine. The samples were assessed under the scanning electron microscope to check for the adhesive remnant index (ARI) and tag depth. Results: There was a statistically significant decrease in the mean SBS of the irradiated samples compared to the non-irradiated teeth. The non-irradiated, aged samples showed a majority of ARI scoring 1 and 2. Whereas, the irradiated samples showed ARI scoring 2 and 3. Approximately, 77·3% of the non-irradiated samples showed no adhesive present on the tooth surface, and 27·2% of the irradiated samples had more than 50% adhesive present on the enamel surface. Conclusion: There is a statistically significant decrease in SBS of irradiated enamel compared to that of non-irradiated teeth. However, the SBS observed in the three groups was well above the ideal SBS for orthodontic bonding, that is, 5·6–6·8 MPa. The adhesive remnant was found on all samples of the irradiated group. Deeper adhesive resin tags were found in the irradiated group in the resin–enamel interface.


2019 ◽  
Vol 7 (3) ◽  
pp. 80 ◽  
Author(s):  
Esin Özlek ◽  
Prasanna Neelakantan ◽  
Jukka Pekka Matinlinna ◽  
Sema Belli ◽  
Mehmet Ugur ◽  
...  

The aim of this in vitro study was to evaluate the adhesion strength of two new fiber post systems (FiberSite™ Post and Cytec™ Blanco Post) cemented with two different adhesive resin cements (Panavia™ SA and Maxcem™ Elite). Root canals of sixty extracted human mandibular premolars were prepared using ProTaper Universal™ rotary files (Dentsply Sirona Endodontics, York, PA, USA). The root canals were irrigated with 5.25% sodium hypochlorite (NaOCl) during instrumentation. After root canal preparation, the canals were irrigated with 2 mL of 17% EDTA (1 min), followed by 2 mL of 5.25% (5 min) NaOCI, and 2 mL saline. The root canals were dried with paper points and divided randomly into two study groups (n = 30) according to the type of post system: Group 1, FiberSite™ Post (MegaDental, Partanna, Italy); and group 2, Cytec™ Blanco Post (Hahnenkratt, Königsbach-Stein, Germany), with one of the two adhesive resin cements: Subgroup A, Panavia™ SA Cement Plus Automix (Kuraray, Osaka, Japan); subgroup B, Maxcem™ Elite (Kerr, Orange, CA, USA). Following thermocycling, the adhesion strength was evaluated using the push-out adhesion (bond) strength test. Fractographic analysis was performed using stereomicroscope. The data were analyzed using two-way analysis of variance (p = 0.05). The adhesion strength values of both the posts were significantly higher when cemented with subgroup B (Maxcem™ Elite). The highest adhesion strength value was demonstrated by group 1B (FiberSite™ post cemented with Maxcem™ Elite cement). The type of post did not have a significant impact on the bond strength values for either cement material.


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