EVALUATION OF STRENGTH CHARACTERISTICS OF ENDOCROWNS FROM HYBRID CERAMICS

2021 ◽  
Vol 17 (37) ◽  
pp. 204-211
Author(s):  
Aleksei DOROFEEV ◽  
Ivan KUZNETSOV
Keyword(s):  
Maximum Load ◽  
Dental Restoration ◽  
Endodontic Treatment ◽  
Strength Characteristics ◽  
Root Canals ◽  
Group 2 ◽  
The Moment ◽  
Ceramic Restorations ◽  
Hybrid Ceramic ◽  
Group 1

Background: Restoration of teeth after endodontic treatment is an urgent problem. There is a large selection of materials and structures for dental restoration after endodontic treatment. Aim: This work aimed to determine the strength characteristics of endocrowns made of hybrid ceramics, depending on various conditions. Methods: The study involved 40 samples of removed teeth (mandibular molars). Mechanical and medical treatment of root canals was previously carried out in the teeth, after which the root canals were sealed with a sealer and gutta-percha. The defect in the crown part of the tooth was repaired with a hybrid ceramic endocrown. Endocrowns were made by milling. The endorocrowns were cemented according to the standard cementation protocol for ceramic restorations. All tooth samples were divided into 2 groups of 20 teeth each group. Group 1 was placed in the thermostat for 24 hours at a temperature of +37±1°C, and group 2 was subjected to thermal cycling. After that, the samples of the studied groups were subjected to uniaxial compression until the moment of destruction. The measurements of the maximum load (kN), maximum stress (MPa), and % of deformation at the moment of failure were carried out. All the results obtained were statistically processed. Results and Discussion: According to the results of the study, the samples of group 1 showed higher values of strength and elasticity than samples of group 2. Conclusions: Thus thermocycling, which simulates the natural oral environment negatively affects the durability of the hybrid ceramic. However, the obtained values make it possible to use it for the restoration of teeth after endodontic treatment

scholarly journals Influence of the EDTA, Nd:YAG laser and association of both on the filling of artificial lateral root canals

2004 ◽  
Vol 12 (1) ◽  
pp. 22-26 ◽  
Author(s):  
Fernanda Gomes de Moraes ◽  
Clovis Monteiro Bramante ◽  
Ivaldo Gomes de Moraes ◽  
Everdan Carneiro ◽  
Renato Menezes
Keyword(s):  
Statistical Analysis ◽  
Nd:Yag Laser ◽  
Lateral Root ◽  
Hybrid Technique ◽  
Apical Portion ◽  
Root Canals ◽  
Group 3 ◽  
Sodium Hypochloride ◽  
Group 2 ◽  
Group 1

This study aimed at evaluating the influence of EDTA, Nd:YAG laser and the combination of both for filling of artificial lateral root canals. Forty-five human mandibular premolars were employed, on which three artificial lateral root canals were prepared by means of a reamer with a similar diameter to a K file #15. The teeth were instrumented through the stepback technique employing Gates Glidden burs at the middle and cervical thirds and manual files at the apical portion, and irrigation with 1% sodium hypochloride. The teeth were divided in three groups: Group 1 -EDTA for 5 minutes; Group 2 -application of Nd:YAG laser at 15 Hz, 100 mJ and 1.5 Watts; and Group 3 - association of both. Roots were filled through the Tagger's hybrid technique, radiographed and the radiographs were digitized. Scores were assigned to the filling of the lateral root canals. Statistical analysis revealed no significant differences between the entire groups and also on the analysis of each third.

scholarly journals Fracture resistance of immature teeth filled with mineral trioxide aggregate, bioaggregate, and biodentine

2016 ◽  
Vol 10 (02) ◽  
pp. 220-224 ◽  
Author(s):  
Emre Bayram ◽  
Huda Melike Bayram
Keyword(s):  
Fracture Resistance ◽  
Mineral Trioxide Aggregate ◽  
Mean Values ◽  
Root Canals ◽  
Immature Teeth ◽  
Significant Difference ◽  
Group 3 ◽  
Group 2 ◽  
Post Hoc ◽  
Group 1

ABSTRACT Objective: The purpose of this study was to evaluate fracture resistance of teeth with immature apices treated with coronal placement of mineral trioxide aggregate (MTA), bioaggregate (BA), and Biodentine. Materials and Methods: Forty-one freshly extracted, single-rooted human premolar teeth were used for the study. At first, the root length was standardized to 9 mm. The crown-down technique was used for the preparation of the root canals using the rotary ProTaper system (Dentsply Maillefer, Ballaigues, Switzerland) of F3 (30). Peeso reamer no. 6 was stepped out from the apex to simulate an incompletely formed root. The prepared roots were randomly assigned to one control (n = 5) and three experimental (n = 12) groups, as described below. Group 1: White MTA (Angelus, Londrina, Brazil) was prepared as per the manufacturer's instructions and compacted into the root canal using MAP system (Dentsply Maillefer, Ballaigues, Switzerland) and condensed by pluggers (Angelus, Londrina, Brazil). Group 2: The canals were filled with DiaRoot-BA (DiaDent Group International, Canada). Group 3: Biodentine (Septodont, Saint Maur des Fosses, France) solution was mixed with the capsule powder and condensed using pluggers. Instron was used to determine the maximum horizontal load to fracture the tooth, placing the tip 3 mm incisal to the cementoenamel junction. Mean values of the fracture strength were compared by ANOVA followed by a post hoc test. P < 0.05 was considered statistically significant. Results: No significant difference was observed among the MTA, BA, and biodentine experimental groups. Conclusion: All the three materials tested, may be used as effective strengthening agents for immature teeth.

scholarly journals Efficacy of ProTaper Retreatment System in Root Canals Obturated with Gutta-Percha Using Two Different Sealers and GuttaFlow

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Jaya Siotia ◽  
Shashi Rashmi Acharya ◽  
Sunil Kumar Gupta
Keyword(s):  
Area Ratio ◽  
Variance Test ◽  
Root Canals ◽  
Gutta Percha ◽  
Significant Difference ◽  
Ah Plus ◽  
Group 3 ◽  
Group 2 ◽  
Silicon Based ◽  
Group 1

Objective. To compare the efficacy of ProTaper retreatment files in removing three different obturating materials.Study Design. Forty-five human, single-rooted premolars were divided into three experimental groups. Group 1 was obturated with gutta-percha and AH Plus sealer, Group 2 was obturated with gutta-percha and zinc oxide eugenol sealer, and Group 3 was obturated with GuttaFlow. Retreatment was done using the ProTaper universal rotary retreatment files. Root halves were visualized using magnifying loops at 3X magnification and optical stereomicroscope at 10X magnification. Images were analyzed using AutoCAD 2004 software to calculate area of the remaining debris in the canal. For statistical analysis were used variance test and ANOVA.Results. Total debris/canal area ratio between the three groups showed a statistically significant difference (P<0.001).Conclusion. ProTaper retreatment system did not produce completely clean canals in any of the groups. However, it had the best efficacy towards removing silicon based obturating material GuttaFlow.

scholarly journals A comparative study of protaper and twisted file nickel titanium instruments in curved canals preparation

2013 ◽  
Vol 60 (4) ◽  
pp. 175-182
Author(s):  
Lima De ◽  
Giselle Nevares ◽  
Felipe Xavier ◽  
Ferraz Gominho ◽  
Albuquerque de
Keyword(s):  
Cross Sections ◽  
Root Canal ◽  
Nickel Titanium ◽  
Torque Control ◽  
Cross Sectional ◽  
Root Canals ◽  
Group 2 ◽  
Mean Differences ◽  
Root Canal Instrumentation ◽  
Group 1

Introduction. Root canal instrumentation is performed to achieve cleaning and shaping with maximum preservation of its original anatomy. However, in curved canals this approach may cause excessive damage or canal transportation. The present study aimed to evaluate changes in dentin wall caused by instrumentation of curved canals using two nickel titanium rotary systems, ProTaper and Twisted File. Material and Methods. Twenty five extracted human mandibular first molars with two separated mesial root canals were selected. Distal roots were amputated and 50 canals (25 mesiobuccal and 25 mesiolingual) were randomly assigned into two groups: group 1 - ProTaper, and group 2 - Twisted File. All files were used with torque control engine, following the manufacturer instructions. The final instruments were F3 (group 1) and #30/.06 (group 2). Pre and postoperative cross sections were obtained from coronal, middle, and apical portions. Changes in dentin wall were measured and evaluated using Bramante method and digital image software. Statistical analysis was performed using the Mann Whitney U test (p<0.05). Results. The ammount of dentin removed by ProTaper in cervical and middle canal thirds was significantly greater than with Twisted File (p=0.040 and p=0.043). ProTaper eliminated significantly greater ammount of dentin than Twisted File from mesial wall in coronal sections (p=0.039). Mean differences in distance from the center to other walls were not statistically significant in the middle and apical thirds of both groups (p>0.05). Conclusion. ProTaper system produced greater changes in cross sectional area of the root canal compared to Twisted File system.

scholarly journals Smear-layer Removal Using Two Instrumentation and Irrigation Techniques in a Closed System

2012 ◽  
Vol 2 (3) ◽  
pp. 60
Author(s):  
Sadullah Kaya
Keyword(s):  
Closed System ◽  
Native Speakers ◽  
Smear Layer ◽  
Continuous Irrigation ◽  
Layer Removal ◽  
Root Canals ◽  
Irrigation Methods ◽  
Native Speakers Of English ◽  
Group 2 ◽  
Group 1

Aim: The aim of this study was to evaluate the effectiveness of two instrumentation and irrigant techniques in smear-layer removal from root canals. Methodology: Thirty single-rooted teeth were randomly divided into two groups. Group 1 (continuous irrigation) was prepared using Self-adjusting file, and group 2 (manual irrigation; conventional needle irrigation) was prepared using with ProTaper file system. Groups were irrigated using sodium hypochlorite (5%) as an initial irrigant following MTAD in a closed system. Canals were bisected and examined by scanning electron microscopy. Smear layers were evaluated using a five-point scoring system with 2500x magnification. Results: Smear layers were eliminated in the coronal, middle, and apical thirds of the root canal, respectively, in 93%, 80%, and 60% of samples in the group 1, and 67%, 60%, and 27% in the group 2, of the coronal, middle, and apical thirds of the root canals, respectively. Evaluation by SEM showed continuous irrigation differed not-significantly from the manual irrigation group in all areas (P >0.05). Conclusions: Smear layer can be removed properly with suitable irrigation methods. How to cite this article: Kaya S. Smear-layer Removal Using Two Instrumentation and Irrigation Techniques in a Closed System. Int Dent Res 2012;2:60-66. Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

scholarly journals Trauma Coagulopathy and Its Outcomes

Medicina ◽  
2020 ◽  
Vol 56 (4) ◽  
pp. 205 ◽  
Author(s):  
Gabriele Savioli ◽  
Iride Francesca Ceresa ◽  
Sarah Macedonio ◽  
Sebastiano Gerosa ◽  
Mirko Belliato ◽  
...  
Keyword(s):  
Injury Severity Score ◽  
Severity Score ◽  
Injury Severity ◽  
Hemodynamic Instability ◽  
Hospitalization Rate ◽  
Low Oxygen ◽  
Group 2 ◽  
The Moment ◽  
Length Of Hospitalization ◽  
Group 1

Background and Objectives: Trauma coagulopathy begins at the moment of trauma. This study investigated whether coagulopathy upon arrival in the emergency room (ER) is correlated with increased hemotransfusion requirement, more hemodynamic instability, more severe anatomical damage, a greater need for hospitalization, and hospitalization in the intensive care unit (ICU). We also analyzed whether trauma coagulopathy is correlated with unfavorable indices, such as acidemia, lactate increase, and base excess (BE) increase. Material and Methods: We conducted a prospective, monocentric, observational study of all patients (n = 503) referred to the Department of Emergency and Acceptance, IRCCS Fondazione Policlinico San Matteo, Pavia, for major trauma from 1 January 2018 to 30 January 2019. Results: Of the 503 patients, 204 had trauma coagulopathy (group 1), whereas 299 patients (group 2) did not. Group 1 had a higher hemotransfusion rate than group 2. In group 1, 15% of patients showed hemodynamic instability compared with only 8% of group 2. The shock index (SI) distribution was worse in group 1 than in group 2. Group 1 was more often hypotensive, tachycardic, and with low oxygen saturation, and had a more severe injury severity score than group 2. In addition, 47% of group 1 had three or more body districts involved compared with 23% of group 2. The hospitalization rate was higher in group 1 than in group 2 (76% vs. 58%). The length of hospitalization was >10 days for 45% of group 1 compared with 28% of group 2. The hospitalization rate in the ICU was higher in group 1 than in group 2 (22% vs. 14.8%). The average duration of ICU hospitalization was longer in group 1 than in group 2 (12.5 vs. 9.78 days). Mortality was higher in group 1 than in group 2 (3.92% vs. 0.98%). Group 1 more often had acidemia and high lactates than group 2. Group 1 also more often had BE <−6. Conclusions: Trauma coagulopathy patients, upon arrival in the ER, have greater hemotransfusion (p = 0.016) requirements and need hospitalization (p = 0.032) more frequently than patients without trauma coagulopathy. Trauma coagulopathy seems to be more present in patients with a higher injury severity score (ISS) (p = 0.000) and a greater number of anatomical districts involved (p = 0.000). Head trauma (p = 0.000) and abdominal trauma (p = 0.057) seem related to the development of trauma coagulopathy. Males seem more exposed than females in developing trauma coagulopathy (p = 0.018). Upon arrival in the ER, the presence of tachycardia or alteration of SI and its derivatives can allow early detection of patients with trauma coagulopathy.

scholarly journals Cleaning the apical third of curved canals after different irrigation protocols

2012 ◽  
Vol 23 (4) ◽  
pp. 351-356 ◽  
Author(s):  
Érika Sales Joviano Pereira ◽  
Isabella Faria da Cunha Peixoto ◽  
Rodrigo Keigo Lopes Nakagawa ◽  
Vicente Tadeu Lopes Buono ◽  
Maria Guiomar de Azevedo Bahia
Keyword(s):  
Electron Microscopy ◽  
Universal System ◽  
Root Canals ◽  
Length Group ◽  
Working Length ◽  
Debris Removal ◽  
Canal Systems ◽  
Group 2 ◽  
Scanning Electron ◽  
Group 1

This study evaluated the protocols of sonic and vacuum irrigation regarding the capacity of debris removal from root canal systems. Canal preparations were carried out on 30 mandibular first molars using the ProTaper Universal System. Teeth were divided into two experimental groups (n=15): Group 1: sonic irrigation and Group 2: vacuum irrigation protocol. Subsequently, the mesial roots were sectioned and observed by stereomicroscopy and scanning electron microscopy. Three independent examiners evaluated images of the apical thirds according to the following scores: 1= small presence of debris, 2= moderate presence of debris, and 3= dense presence of debris. Data were analyzed with ANOVA and Kruskal-Wallis tests (α=0.05). Comparison among the groups revealed that at the apical third, the root halves of Group 1 had significantly less surface debris (p=0.002) than those of Group 2. However, at 2 mm from the working length, Group 2's specimens showed less remaining debris in approximately 75% of the analyzed root canals. At the whole apical third, the sonic irrigation protocol removed significantly more debris than the vacuum protocol. However, in the region at 2 mm from the working length, the second irrigation method demonstrated a better performance.

scholarly journals Comparison of canal transportation and centering ability of manual K-files and reciprocating files in glide path preparation: a micro-computed tomography study of constricted canals

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jing-Yi Liu ◽  
Zhi-Xiong Zhou ◽  
Wei-Ju Tseng ◽  
Bekir Karabucak
Keyword(s):  
Computed Tomography ◽  
Clinical Approach ◽  
Reciprocating Motion ◽  
Micro Computed Tomography ◽  
Root Canals ◽  
Glide Path ◽  
Significant Difference ◽  
Canal Transportation ◽  
Group 2 ◽  
Group 1

Abstract Background Optimum Glide Path (OGP) is a new reciprocating motion aiming to perform efficient glide path preparation in constricted canals. The aim of this study was to investigate and compare manual and OGP movement in terms of canal transportation and centering ability in glide path preparation of constricted canals. Methods Thirty constricted mesial root canals of mandibular molars, with initial apical size no larger than ISO#8, were selected and negotiated with #6–#8 K-files under the microscope. Canals were randomly divided into two experimental groups: Group 1 (MAN, n = 15): Glide path was established by using #10-#15 stainless steel K-files manually; Group 2 (OGP, n = 15): #10-#15 Mechanical Glide Path super-files were used with OGP motion (OGP 90°, 300 rpm). Each instrument was used to prepare only 2 canals (as in one mesial root). Canals were scanned before and after glide path preparation with micro-computed tomography (micro-CT) to evaluate root canal transportation and centering ratio at 1, 3 and 5 mm levels from the root apex. File distortions and separations were recorded. Paired t-test was used to statistically evaluate the data (P < .05). Results Group 2 showed a significantly lower transportation value than group 1 at 1-mm and 3-mm levels (P < .05), however the difference at 5-mm level was not significant. There was no significant difference regarding the centering ratio between the groups. Six #10 K-files were severely distorted in group 1, while no file separation or distortion was found in group 2. Conclusions OGP motion performed significantly less canal transportation (apical 3 mm) and file distortion during glide path establishment in constricted canals comparing to manual motion, while the centering ability between the two was similar. Clinical relevance OGP reciprocating motion provides a safer and efficient clinical approach compared to traditional manual motion in glide path establishment with small files in constricted canals.

scholarly journals Biomechanical Comparison of Flexor Digitorum Profundus Avulsion Repair

2019 ◽  
Vol 08 (04) ◽  
pp. 312-316 ◽  
Author(s):  
Jill G. Putnam ◽  
Damon Adamany
Keyword(s):  
Suture Anchor ◽  
Tendon Repair ◽  
Maximum Load ◽  
Flexor Digitorum Profundus ◽  
Anchor Group ◽  
Load To Failure ◽  
Group 3 ◽  
Group 2 ◽  
Flexor Digitorum ◽  
Group 1

Purpose Multiple repair techniques have been investigated for flexor digitorum profundus (FDP) tendon avulsions. The purpose of this study is to compare the biomechanical characteristics of a new fully threaded titanium suture anchor with previously examined fixation techniques. Methods Repair of FDP tendon avulsions was performed in 18 fresh-frozen cadavers using one of three implants: Nano Corkscrew FT 1.7 mm suture anchor (Group 1; Arthrex, Inc., Naples, FL; n = 6), Mitek Micro 1.3 mm suture anchor (Group 2; Mitek Surgical Products, Westwood, MA; n = 6), or pullout suture button fixation (Group 3; n = 6). Constructs were preloaded before testing load to failure. For each trial, elongation at 20 N and maximum load, mean load to failure, stiffness, and failure mechanism were recorded. Results Load to failure occurred in all trials. Mean load to failure was significantly greater for Group 1 (61.6 ± 18.9 N) compared to Group 2 (42.5 ± 4.2 N; p < 0.05) and Group 3 (41.6 N ± 8.0 N; p < 0.05). Stiffness was significantly greater in Groups 1 and 2 compared to Group 3 (6.9 ± 2.2 N/mm vs. 6.1 ± 0.8 N/mm vs. 3.1 N/mm ± 0.5 N/mm, respectively, p < 0.01). Mechanism of failure differed between the groups: Group 1 broke at the anchor in two trials and tore through the tendon in three trials, Group 2's suture universally broke at the anchor, and Group 3's trials mainly failed at the button. Conclusions The Nano Corkscrew anchor (Group 1) has a significantly higher load to failure when compared with the other techniques. The higher load to failure of the corkscrew anchor provides a secure method for flexor tendon repair in zone I. Clinical Relevance A fully threaded titanium suture anchor used for FDP tendon avulsion injuries is likely to withstand early active range of motion protocols.

scholarly journals The Effects of Water and Acetone-based Dentin Adhesives on Apical Microleakage

2004 ◽  
Vol 5 (2) ◽  
pp. 93-101 ◽  
Author(s):  
Oya Bala ◽  
L. Sibel Karadag ◽  
Emin Türköz ◽  
Tansev Mihçioğlu
Keyword(s):  
Adhesive System ◽  
Root Canals ◽  
Gutta Percha ◽  
Dentin Adhesives ◽  
Significant Difference ◽  
Ah Plus ◽  
Group 2 ◽  
Materials Used ◽  
Group 1

Abstract In this study, the aim was to assess the in vitro apical microleakage of a resin-based sealer used with two different adhesives. Thirty nine freshly extracted maxillary incisors were used. The teeth were decoronated at the cemento-enamel junction with a water-cooled fissure bur. Chemo-mechanical debridement of the root canals was accomplished with the step-back technique. The smear layer was removed by 19% ethylenediamine tetra acetic acid (EDTA). The roots were then divided into three experimental groups of thirteen teeth in each. Specimens in group 1 were filled with gutta-percha, AH Plus sealer, and water-based adhesive system (Syntac Single Component). Group 2 specimens were filled with gutta-percha, AH Plus sealer, and acetone-based dentin adhesive (Prime & Bond NT). Specimens of group 3 were filled with only gutta-percha and AH Plus sealer (no adhesive was applied). The teeth were immersed into 2% methylene blue solution. Apical sealing qualities were assessed by measuring the linear dye penetration with a stereomicroscope. Dentin tubule penetration was observed under scanning electron microscopy (SEM). Results showed no statistically significant difference between the materials used, however, the leakage in group 2 was less than group 1 and 3. Citation Karadag LS, Bala O, Türköz E, Mihçioğlu T. The Effects of Water and Acetone-based Dentin Adhesives on Apical Microleakage. J Contemp Dent Pract 2004 May;(5)2:093-101.

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