scholarly journals Ex Vivo Evaluation of a Restoration Protocol for Teeth with Simulated Incomplete Rhizogenesis

Author(s):  
Cristina Retana-Lobo DDS, MSD ◽  
Jessie Reyes-Carmona DDS, MSD, PhD

The use of phosphate buffered saline (PBS) as an intracanal medication triggers a biomineralization process within mineral trioxide aggregate (MTA) apical plugs during the apexification process in teeth with incomplete rhizogenesis. However, no consensus is available in the literature regarding a restorative protocol for this type of treatment. Thus, the objective of this study was to use scanning electron microscopy (SEM) to evaluate the processes of biomineralization and adhesion in a restorative protocol for teeth with simulated incomplete rhizogenesis. Methodology: Root sections with a thickness of 2mm and cavities with a diameter of 2mm were used. The sections were randomly prepared and filled with the following materials: Group 1 (n=12), ProRoot MTA; and Group 2 (n=12): MTA Exp. Subsequently, the samples were immersed in PBS for 35 days. Every 5 days, the PBS was replaced, and the precipitates were collected, dried, and weighed. Two samples from each group were analyzed by SEM. Moreover, 24 single-rooted teeth were standardized, incomplete rhizogenesis was simulated, and 5-mm-long apical plugs were created with Pro Root MTA. As an intracanal medication, PBS was used for different periods of time: Group 1:48 h; Group 2:7 days; and Group 3:15 days. Then, fiberglass posts were cemented with the REBILDA® Post System. The samples were prepared and analyzed by SEM. Results: ProRoot MTA and MTA Exp effectively promoted the formation of carbonated apatite precipitates and biomineralization with dentin. ProRoot MTA yielded more carbonated apatite precipitates compared to MTA Exp (p=0.0536). The use of PBS as an intracanal medication for 7 and 15 days promoted intratubular mineralization (MIT), and treatment for 15 days was more effective (p < 0.05). The REBILDA® Post System effectively promoted the microimbrication of the adhesive system and the formation of resinous tags with lateral adhesive branches. Conclusion: Apexification with MTA associated with the use of PBS as an intracanal medication for 15 days, in addition to the use of the REBILDA® Post System, seems to be a feasible restorative protocol.

2016 ◽  
Vol 10 (02) ◽  
pp. 220-224 ◽  
Author(s):  
Emre Bayram ◽  
Huda Melike Bayram

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.


2021 ◽  
Vol 11 (Suppl. 1) ◽  
pp. 67-73
Author(s):  
Ahmet Akay ◽  
Özkan Adıgüzel ◽  
Seda Erkan Akay ◽  
Sadullah Kaya

Aim: The purpose of this in vitro study is to compare the cyclic fatigue resistance of Reciproc Nickel-Titanium (Ni-Ti) rotary files while operating root canals using in three different reciprocal angles. Methodology: Forty-five pieces of Reciproc R25 canal files were tested using artificial canals with a 60° angle of curvature, 5 mm curvature radius, and 1.5 mm diameter carved into a stainless steel block. The Ni-Ti files were checked with a stereomicroscope and then randomly separated into 3 groups. Group 1 consisted of reciprocal angles CCW 150°–CW 30°, Group 2 consisted of CCW 180°–CW 60°, and Group 3 consisted of CCW 210°–CW 90°. The duration of the cyclic fatigue being measured, elapsed time until a file fractured was determined with a chronometer. The lengths of the fractured pieces were measured with a digital caliper. After the cyclic fatigue test, two samples from each group were examined with a Scanning Electron Microscope (SEM) to determine the signs of cyclic fatigue. Results: One-way analysis of variance (ANOVA) was applied to the normally distributed groups (p<0,05). Since there was a significant statistical difference of file’s cyclic fatigue resistance (p=0,001) between the groups, Tukey’s honestly significant difference (HSD) post-hoc pairwise comparison test were used for determine to between which groups. While there were statistically significant differences between Group 1 and Group 2 (p=0,001), and between Group 1 and Group 3 (p=0,001), there was no significant difference between Group 2 and Group 3 (p=0,376). Group 1 displayed the highest resistance to cyclic fatigue. There were no statistically significant differences between the lengths of the fractured files within the three groups according to the one-way analysis of variance (p=0,847). Conclusion: In our study, it was observed that the reciprocal angles of CCW 150°–CW 30°, which were also suggested by the file manufacturer firms, had the highest fracture resistance against cyclic fatigue.   How to cite this article: Akay A, Adıgüzel Ö, Erkan Akay S, Kaya S. Comparison of cyclic fatigue of a reciprocating file system at different angles of rotation. Int Dent Res 2021;11(Suppl.1):67-72. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.11   Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.  


2005 ◽  
Vol 16 (3) ◽  
pp. 187-191 ◽  
Author(s):  
Claudio Hideki Kubo ◽  
Ana Paula Martins Gomes ◽  
Maria Nadir Gasparoto Mancini

The purpose of this study was to evaluate the apical seal in root apex treated with different demineralization agents and retrofilled with mineral trioxide aggregate (MTA) using marginal dye leakage. Fifty-six, human single-rooted teeth were instrumented, filled, resected and had retrofilling cavities prepared with ultrasonic tips. Demineralizing agents were applied before the apical cavities were retrofilled with Pro Root MTA. The specimens were assigned to 4 groups (n=14), as follows: group 1 (no demineralizing agent); group 2 (35% phosphoric acid, for 15 s); group 3 (17% EDTA solution, pH 7, for 3 min); and group 4 (24% EDTA gel, pH 7, for 4 min). The extension of dye (2% rhodamine B, at 37°C, for 24 h) penetration was measured in millimeters using a stereomicroscope. Results were statistically analyzed by ANOVA and Tukey's test at 5% significance level. Among the experimental groups, the least extension of dye penetration was observed in group 1 (1.89 mm), followed by groups 2 (2.18 mm), 4 (2.54 mm) and 3 (2.64 mm). No statistically significant differences (p<0.05) were found in marginal microleakage among groups 1, 2 and 4 and groups 2, 3 and 4. Based on the results obtained in this study, it may be concluded that the application of demineralizing agents cannot be recommended when MTA is used in periradicular surgeries.


2003 ◽  
Vol 112 (4) ◽  
pp. 307-313 ◽  
Author(s):  
Eric M. Genden ◽  
Patrick J. Gannon ◽  
Maria Deftereos ◽  
Shane Smith ◽  
Mark L. Urken

The inability to reconstruct extensive and often life-threatening tracheal defects is a clinical dilemma. The objective of this study was to achieve microvascular revascularization and transplantation of long-segment circumferential tracheal allografts in a canine model. Fifteen mongrel dogs were randomly assigned to 5 treatment groups. Twelve dogs underwent an excision of an 8-cm tracheal segment followed by transplantation and microvascular revascularization of an 8-cm cervical trachea allograft. Group 1 (n = 4) was treated with 10 mg/kg per day of cyclosporin A (CsA) and 7.5 mg/kg per day of mycophenolate mofetil (MM). Group 2 (n = 4) was treated with 5 mg/kg per day of CsA and 7.5 mg/kg per day of MM. Group 3 (n = 4) was treated with 2.5 mg/kg per day of CsA and 7.5 mg/kg per day of MM. Group 4 (n = 2) underwent an autograft tracheal transplant and received postoperative 2.5 mg/kg per day of CsA and 7.5 mg/kg per day of MM. Group 5 (n = 1) did not undergo surgery, but received postoperative 2.5 mg/kg per day of CsA and 7.5 mg/kg per day of MM. The animals were maintained for a duration of 30 days, during which time the graft was assessed by routine endoscopic examination and tracheal biopsies. Ex vivo, tracheal autografts were examined grossly for graft healing and microscopically for histologic architecture. The mean survival times were 13.25 days (group 1), 16 days (group 2), and 20 days (group 3). There was 1 early allograft failure secondary to microvascular thrombosis, and there were 4 delayed failures secondary to postoperative wound infections. Five dogs were euthanized before the end of the 30-day observation period because of failure to thrive or hypocalcemic tetany. None of the dogs in the study demonstrated endoscopic or histologic evidence of rejection before euthanasia. Postmortem examination of the surviving dogs demonstrated normal histologic architecture without evidence of rejection. For the first time, we have achieved allotransplantation of long tracheal segments based on the cranial thyroid artery and internal jugular vein. Minimal systemic immunosuppression appears to be associated with a higher survival rate and a lower complication rate.


2017 ◽  
Vol 30 (02) ◽  
pp. 118-124 ◽  
Author(s):  
Aline Macedo ◽  
John Runciman ◽  
Tom Gibson ◽  
Bruno Minto ◽  
Noel Moens

SummaryObjective: To evaluate the torsional properties of the Targon® Vet Nail System (TVS) in small canine femurs and to compare these properties to those of the 2.4 mm LC-DCP® plates.Methods: Thirty-six cadaveric femurs were allocated to three groups (n = 12). In all bones, points just distal to the lesser trochanter and just proximal to the fabellae were marked and a midshaft transverse osteotomy was performed. Group 1: bones were fixed with the 2.5 mm TVS with the bolts applied at the pre-identified marks. Group 2: A TVS system with 25% shorter inter-bolt distance was used. Group 3: A 7-hole 2.4 mm LCDCP® plates were applied. All constructs were tested non-destructively for 10 cycles, followed by an acute torsion to failure.Results: Torque at yield was 0.806 ± 0.183 and 0.805 ± 0.093 Nm for groups 1 and 2 and 1.737 ± 0.461 Nm for group 3. Stiffness was 0.05 ± 0.01, 0.05 ± 0.007, and 0.14 ± 0.015 Nm/° for groups 1 to 3 respectively. Maximal angular displacement under cyclic loading was 16.6° ± 2.5°, 15.6° ± 2.1°, and 7.8° ± 1.06° respectively. There was no significant difference for any of the parameters between groups 1 and 2. Both torque at yield and stiffness were significantly greater between group 3 and groups 1 and 2.Clinical significance: The TVS had approximately half the torsional strength and approximately 1/3 of the stiffness of the 2.4 mm bone plate. Slippage of the locking mechanism was probably the cause of the early failure. The system should be considered as a low-strength and low-stiffness system when compared to bone plates.


2021 ◽  
Vol 11 ◽  
Author(s):  
Pierre Bourgeois ◽  
Isabelle Veys ◽  
Danielle Noterman ◽  
Filip De Neubourg ◽  
Marie Chintinne ◽  
...  

BackgroundNear-infrared fluorescence imaging (NIRFI) of breast cancer (BC) after the intravenous (IV) injection of free indocyanine green (fICG) has been reported to be feasible. However, some questions remained unclarified.ObjectiveTo evaluate the distribution of fICG in BC and the axillary lymph nodes (LNs) of women undergoing surgery with complete axillary LN dissection (CALND) and/or selective lymphadenectomy (SLN) of sentinel LNs (NCT no. 01993576 and NCT no. 02027818).MethodsAn intravenous injection of fICG (0.25 mg/kg) was administered to one series of 20 women undergoing treatment with mastectomy, the day before surgery in 5 (group 1) and immediately before surgery in 15 (group 2: tumor localization, 25; and pN+ CALND, 4) as well as to another series of 20 women undergoing treatment with tumorectomy (group 3). A dedicated NIR camera was used for ex vivo fluorescence imaging of the 45 BC lesions and the LNs.ResultsIn group 1, two of the four BC lesions and one large pN+ LN exhibited fluorescence. In contrast, 24 of the 25 tumors in group 2 and all of the tumors in group 3 were fluorescent. The sentinel LNs were all fluorescent, as well as some of the LNs in all CALND specimens. Metastatic cells were found in the fluorescent LNs of the pN+ cases. Fluorescent BC lesions could be identified ex vivo on the surface of the lumpectomy specimen in 14 of 19 cases.ConclusionsWhen fICG is injected intravenously just before surgery, BC can be detected using NIRFI with high sensitivity, with metastatic axillary LNs also showing fluorescence. Such a technical approach seems promising in the management of BC and merits further investigation.


2009 ◽  
Vol 10 (2) ◽  
pp. 67-74 ◽  
Author(s):  
Hacer Deniz Arisu ◽  
Hüma Ömürlü ◽  
Evrim Eligüzeloğlu ◽  
Mine Üçtaşli

Abstract Aim The aim of this study was to evaluate the effects of multiple consecutive coatings of a one-step self-etch adhesive system (Clearfil Tri-S Bond) on the microtensile bond strength (MBS) to dentin. Methods and Materials Nine caries-free human lower third molars were sectioned perpendicular to the long axis to expose the mid-coronal dentin. The teeth were separated into three experimental groups (n=3) according to the number of adhesive resin coats applied. In Group 1 one layer of Clearfil Tri-S Bond was applied according to the manufacturer's instructions. In Group 2 and Group 3 the adhesive was applied in two and three layers, respectively. In these two groups the first layer was applied according to the manufacturer's instructions but the second and third layers of adhesive were not light cured after application. After the placement of the composite, the teeth were sectioned to obtain approximately 1 mm2 beams for testing. Eighteen beams were prepared for each group using the ‘non-trimming’ method. The MBS values of all specimens were tested, and fracture modes were then determined using a stereomicroscope. Results The mean MBS values (in MPa) of Group 1 (one coat of the adhesive) was significantly lower (p=0.04) than those of Group 3 (three applied coats of the adhesive). There were no statistically significant differences between Groups 1 and 2 and Groups 2 and 3. Conclusion Within the limitations of this in vitro study the application of multiple coats of a one-step self-etch adhesive may provide an increase in bond strength compared to the application of only one coat of adhesive. Clinical Significance Three consecutive coats of one-step self-etching adhesive application can improve MBS. Citation Arisu HD, Eligüzeloğlu E, Üçtaşli M, Ömürlü H. Effect of Multiple Consecutive Applications of One-step Self-etch Adhesive on Microtensile Bond Strength. J Contemp Dent Pract 2009 March; (10)2:067-074.


Author(s):  
A. Kirschbaum ◽  
Th. M. Surowiec ◽  
A. Pehl ◽  
Th. Wiesmann ◽  
D. K. Bartsch ◽  
...  

AbstractFollowing non-anatomical resection of lung parenchyma with a Nd:YAG laser, a coagulated surface remains. As ventilation starts, air leakage may occur in this area. The aim of the present study was to investigate, whether additional coagulation either before or after ventilation has an additional sealing effect. Freshly slaughtered porcine heart-lung blocks were prepared. The trachea was connected to a ventilator. Using a Nd:YAG laser (wavelength: 1320 nm, power: 60 W), round lesions (1.5 cm in diameter) with a depth of 1.5 cm were applied to the lung using an 800-μm laser fiber (5 s per lesion). Group 1 (n = 12) was control. Additional coagulation was performed in group 2 (n = 12) without and in group 3 (n = 12) with ventilation restarted. Air leakage (ml) from the lesions was measured. The thickness of each coagulation layer was determined on histological slices. Differences between individual groups were analyzed by one-way ANOVA (significance p < 0.05). After resection, 26.2 ± 2.7 ml of air emerged from the lesions per single respiration in group 1. Air loss in group 2 was 24.6 ± 2.5 ml (p = 0.07) and in group 3 23.7 ± 1.8 ml (p = 0.0098). In comparison to groups 1 and 2 thickness of the coagulation layers in group 3 was significantly increased. After non-anatomical porcine lung resection with a Nd:YAG laser, additional coagulation of the ventilated resection area can reduce air leakage.


2013 ◽  
Vol 31 (4_suppl) ◽  
pp. 47-47
Author(s):  
Luis Carlos Moreira Antunes ◽  
Leandro Bizarro Muller ◽  
Antonio de Barros Lopes ◽  
Renato Borges Fagundes

47 Background: The highest rates of esophageal cancer in Brazil occur in Rio Grande do Sul (18/100,000/year for men), where squamous cell carcinoma is the most common. Furthermore, the incidence of head and neck squamous cell carcinoma (HNSCC) is significant in this region (11/100,000/year for cancer of the oral cavity and 10/100,000/year for laryngeal cancer in men). Tobacco smoking and alcohol consumption are the major risk factors for esophageal squamous cell carcinoma (ESCC) and HNSCC. The role of HPV in the development of ESCC remains controversial. Otherwise, there are some evidence that HPV-related HNSCC is a distinct entity compared with HNSCC associated with smoking and alcohol consumption. Methods: Polymerase chain reaction (PCR) was used to evaluate the presence of Human Papillomavirus from 218 samples from three groups of patients. Group 1 comprised 51 patients with ESCC who underwent esophagectomy, in which two samples from each patient were analyzed: one sample of the tumor and another of normal esophageal mucosa distant from the tumor. Group 2 comprised 37 patients with HNSCC who underwent Lugol chromoendoscopy. In this group, samples were analyzed from the primary tumor, the stained areas of mucosa from the middle esophagus, and, when present, discolored and tumoral areas of the esophageal mucosa. Thirty-seven dyspeptic patients, not exposed to smoking or alcohol consumption, comprised Group 3, in which one sample per patient of mucosa with normal appearance from the middle esophagus was evaluated. Nested-PCR with MY09/11 and GP5/6 L1 primers was used to detect HPV L1 in samples fixed in formalin and stored in paraffin blocks. Results: Of a total of 224 samples fixed in formalin and stored in paraffin, only 6 samples had insufficient material for PCR analysis: one sample from normal distal epithelium in Group 1, one sample from a stained area and 2 samples from unstained areas in Group 2 and two samples from normal esophageal mucosa in Group 3. PCR was positive for one of conserved genes GAPDH, G3PDH or B-globin and negative for HPV DNA in all the 118 samples tested. Conclusions: There is no evidence that HPV is involved in carcinogenesis of the upper aerodigestive tract in southern Brazil.


2020 ◽  
Vol 4 ◽  
pp. 18-24
Author(s):  
Oleksandr Udod ◽  
Olena Borysenko

Photocomposite materials and adhesive systems are used for direct tooth restoration, among which 5th generation systems are most often used. To ensure curing, they are exposed to the light flux of the dental photopolymerizer, but the requirements and conditions of such exposure are insufficiently studied. The aim – clinical evaluation of direct photocomposite restorations of teeth performed using an adhesive system, the curing of which was carried out in different light conditions. Materials and methods. 185 people aged from 19 to 44 years were examined, in which 185 lateral teeth with carious cavities of the 1st class according to Black for medium and deep caries were restored by direct method from nanophotocomposite material. In patients of group 1 during the restoration of 62 teeth the polymerization of the adhesive system of the 5th generation was performed with a light flux of constant intensity 1500 mW/cm², in patients of group 2 were restored 60 teeth with polymerization of the same adhesive system with light flux by "soft start" with a final intensity of 1500 mW/cm², 63 teeth in persons of group 3 were restored with a gradual light effect of 1500 mW/cm² on the adhesive system at the bottom and each of the cavity walls using an additional device. The state of recovery was examined after 12 and 24 months. Results. Within 12 months, the largest total number of disorders according to the clinical criteria "marginal adhesion", "marginal staining", "postoperative sensitivity" and "secondary caries" was found in patients of agroups 1 and 2, violations were found in 10 and 13 restorations, respectively (16.1±4.9 % and 21.7±5.8 % of the number of restorations in each group). In persons of group 3, disorders were identified in 3 restored teeth (4.8±2.6 %), which is statistically significant (p<0.05) better. After 24 months, statistically significant (p<0.05) the best indicators were again in patients of group 3, violations were found only in 4 restorations (6.7±3.2 % of them in this period). The worst was the state of recovery in persons of group 2, they had disorders in 20 restorations (42.6±10.4 %), in patients of group 1 – in 16 restorations (30.8±8.0 %). Conclusions. Direct restoration of teeth from nanophotocomposite material, performed using the 5th generation adhesive system under the condition of its gradual polymerization at the bottom and each of the walls of the carious cavity of сlass 1 according to Black, showed high clinical efficiency, which in 12 and 24 months amounted to, respectively, 93.7±3.4 % and 88.9±3.5 %.


Sign in / Sign up

Export Citation Format

Share Document