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1.
Clin Oral Investig ; 27(6): 2805-2811, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36695972

ABSTRACT

OBJECTIVE: To assess the percentage of marginal gaps and voids in oval-shaped canals obturated by using two warm compaction techniques with a Bio-C sealer and AH Plus Jet. MATERIALS AND METHODS: Forty canines with oval canals were scanned by microcomputed tomography (micro-CT), and root canal preparation was performed with an XP-endo Shaper system and irrigated with 5.25% sodium hypochlorite. Then, the specimens were paired into four groups (n=10) according to the root canal filling technique and endodontic sealer: Bio-C sealer and continuous wave of condensation, Bio-C sealer and Tagger's hybrid, AH Plus Jet and continuous wave of condensation, and AH Plus Jet and Tagger's hybrid. After root canal filling, a new scan was performed. The percentage of marginal gaps and voids was calculated with the ImageJ software, and the data were analyzed statistically using two-way ANOVA and Tukey tests, with a significance level of 5%. RESULTS: The percentage of marginal gaps was significantly lower in the Bio-C sealer than in AH Plus Jet (p=0.021) regardless of the technique. However, no difference was found in the percentage of voids between root canal filling techniques and the endodontic sealer (p>0.05). CONCLUSION: Both sealers and techniques demonstrated good quality of root canal filling. However, the use of the Bio-C sealer enhanced the filling ability by reducing marginal gaps, regardless of the root canal filling technique. CLINICAL RELEVANCE: This study highlights the better performance of the Bio-C sealer in the quality of the root canal filling, reducing marginal gaps when compared to AH Plus Jet independent of the technique.


Subject(s)
Root Canal Filling Materials , X-Ray Microtomography/methods , Dental Pulp Cavity/diagnostic imaging , Root Canal Obturation/methods , Root Canal Preparation/methods , Gutta-Percha , Epoxy Resins
2.
Braz Oral Res ; 36: e068, 2022.
Article in English | MEDLINE | ID: mdl-36507755

ABSTRACT

We aimed to evaluate the penetration of endodontic cement following the removal of calcium hydroxide (Ca(OH)2) dressing using the XP-endo Finisher in association with different irrigating solutions. Sixty premolars were instrumented and applied with a Ca(OH)2 dressing. To remove Ca(OH)2, the teeth were divided into six groups, each with a different volume of sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA), as well as solution stirring time with XP-endo Finisher (0, 30, and 60 sec). Root canals were filled using the lateral condensation technique. Fluorescein dye was added to the cement for microscopic laser scanning analysis. In the generated images, linear measurements were taken in micrometers, and their averages were calculated. To analyze the perimeter penetration ratio of the cement, the total perimeter of the canal and the segment of the total perimeter of the canal where the endodontic cement penetrated into the dentinal tubules were measured in micrometers. We found that using an XP-endo Finisher in irrigation was more effective than using a needle and syringe during the extension and penetration of endodontic cement. Shaking with XP-endo Finisher with 17% EDTA increased the extent and perimeter of the penetration of the endodontic cement into the dentinal tubules. However, using the XP-endo Finisher with EDTA only was more efficient than using the instrument interchangeably in NaOCl and EDTA. Although XP-endo Finisher contributes to the removal of Ca(OH)2, none of the protocols or instruments used removed all Ca(OH)2 from the root system.


Subject(s)
Calcium Hydroxide , Sodium Hypochlorite , Calcium Hydroxide/therapeutic use , Edetic Acid/therapeutic use , Sodium Hypochlorite/therapeutic use , Glass Ionomer Cements , Root Canal Preparation , Dental Pulp Cavity , Root Canal Irrigants/therapeutic use
3.
J Clin Exp Dent ; 14(7): e566-e572, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35912029

ABSTRACT

Background: The filling of the root canal system (RCS) is an important step in endodontic treatment and aims to obtain a three-dimensional sealing of the root canal spaces to prevent bacterial contamination. For this, the selection of an appropriate sealer must be performed synchronously with the choice of the root canal filling technique. This study aims, through an integrative review, to evaluate the quality of root canal filling by comparing thermoplastic and single-cone (SC) techniques. Material and Methods: The Medline/PubMed, Scopus, Web of Science and Virtual Health Library (VHL) databases were used to find articles published until November 2021. The eligibility criteria comprised articles that evaluating the quality of root canal filling comparing thermoplastic techniques with the SC technique using tricalcium silicate-based sealer. Studies that evaluated primary teeth, endodontic retreatment or perforations, different outcomes, and studies that considered artificial teeth or different sealer and material for obturation of different techniques were excluded. For articles that were not available for access, an additional contact with authors were considered. A total of 1699 articles were found. After duplicate removal, the title and abstract of 828 articles were screened. Sixteen articles were considered for full-text analysis, but only ten articles met the eligibility criteria. Data extracted from the studies were discussed and tabulated to allow the comparison of desired factors. Results: Concerning the formation of gaps/voids, the thermoplastic techniques showed better results than the SC technique in 3 articles. On the other hand, 2 articles reported no statistical difference between the tested techniques. In addition, about the penetration of tricalcium silicate-based sealer in the dentinal tubules, of the 5 articles selected, in 4 there was no significant difference between the tested techniques and only one study showed better penetration of the sealer when using thermoplastic techniques. Conclusions: The thermoplastic technique was better in most selected studies regarding gaps and voids, but regarding the penetration of the sealer into the tubules, both techniques were effective. Key words:Root canal filling, thermoplastic techniques, tricalcium silicate.

4.
J Conserv Dent ; 25(1): 78-87, 2022.
Article in English | MEDLINE | ID: mdl-35722065

ABSTRACT

Background: Due to the large number of publications relating the occurrence of dental microcracks to endodontic procedures, this bibliometric study evaluated the scientific pattern and trends in literature and provided an overview of scientific production in this context. Aim: To analyze, quantify, and characterize the scientific production and trends of published articles evaluating dentinal microcracks formation after endodontic treatment procedures between 2010 and 2020 using bibliometric indicators. Materials and Methods: Published articles were found by the search in the Medline (PubMed) and Scopus database using the combination of the following keywords: Dentinal crack OR Dentinal Microcrack OR Crack formation OR Dentin Defect AND Endodontic treatment OR Root canal preparation OR Canal Preparation OR Root canal treatment OR endodontic procedures. The search was also conducted in the Journal of Endodontics and International Endodontic Journal. After inclusion and exclusion criteria application, data from all studies included were collected. Results: Among the 556 results after the search, 45 studies were included and analyzed in this bibliometry. No trend was observed in terms of the increasing number of articles over time. Most of them used an in vitro design, compared the effect of different endodontic techniques/systems for root canal instrumentation on dentinal microcracks formation, and were conducted in Turkey, Brazil, and India. Journal of Endodontics and International Endodontic Journal were the main journals with a higher number of articles published. Interestingly, studies conducted with some funding did not lead to higher citation numbers. Moreover, a relevant proportion of studies did not consider the inclusion of control groups, baseline evaluation, or statistical analysis. Micro-CT was the main technique used to evaluate microcrack presence. Conclusion: Microcrack formation after the use of different endodontic techniques/systems has been constantly evaluated in the literature. There is a pattern of methodologies used, which may explain the concentration of these studies in specific journals and countries.

5.
Braz. oral res. (Online) ; 36: e068, 2022. tab, graf
Article in English | LILACS-Express | LILACS, BBO - Dentistry | ID: biblio-1374736

ABSTRACT

Abstract: We aimed to evaluate the penetration of endodontic cement following the removal of calcium hydroxide (Ca(OH)2) dressing using the XP-endo Finisher in association with different irrigating solutions. Sixty premolars were instrumented and applied with a Ca(OH)2 dressing. To remove Ca(OH)2, the teeth were divided into six groups, each with a different volume of sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA), as well as solution stirring time with XP-endo Finisher (0, 30, and 60 sec). Root canals were filled using the lateral condensation technique. Fluorescein dye was added to the cement for microscopic laser scanning analysis. In the generated images, linear measurements were taken in micrometers, and their averages were calculated. To analyze the perimeter penetration ratio of the cement, the total perimeter of the canal and the segment of the total perimeter of the canal where the endodontic cement penetrated into the dentinal tubules were measured in micrometers. We found that using an XP-endo Finisher in irrigation was more effective than using a needle and syringe during the extension and penetration of endodontic cement. Shaking with XP-endo Finisher with 17% EDTA increased the extent and perimeter of the penetration of the endodontic cement into the dentinal tubules. However, using the XP-endo Finisher with EDTA only was more efficient than using the instrument interchangeably in NaOCl and EDTA. Although XP-endo Finisher contributes to the removal of Ca(OH)2, none of the protocols or instruments used removed all Ca(OH)2 from the root system.

6.
Restor Dent Endod ; 46(4): e53, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34909417

ABSTRACT

OBJECTIVES: This study evaluates the bond strength and marginal adaptation of mineral trioxide aggregate (MTA) Repair HP and Biodentine used as apical plugs; MTA was used as reference material for comparison. MATERIALS AND METHODS: A total of 30 single-rooted teeth with standardized, artificially created open apices were randomly divided into 3 groups (n = 10 per group), according to the material used to form 6-mm-thick apical plugs: group 1 (MTA Repair HP); group 2 (Biodentine); and group 3 (white MTA). Subsequently, the specimens were transversely sectioned to obtain 2 (cervical and apical) 2.5-mm-thick slices per root. Epoxy resin replicas were observed under a scanning electron microscope to measure the gap size at the material/dentin interface (the largest and smaller gaps were recorded for each replica). The bond strength of the investigated materials to dentin was determined using the push-out test. The variable bond strengths and gap sizes were evaluated independently at the apical and cervical root dentin slices. Data were analyzed using descriptive and analytic statistics. RESULTS: The comparison between the groups regarding the variables' bond strengths and gap sizes showed no statistical difference (p > 0.05) except for a single difference in the smallest gap at the cervical root dentin slice, which was higher in group 3 than in group 1 (p < 0.05). CONCLUSIONS: The bond strength and marginal adaptation to root canal walls of MTA HP and Biodentine cement were comparable to white MTA.

7.
Dent. press endod ; 11(3): 14-23, Sept-Dec.2021.
Article in English | LILACS | ID: biblio-1378576

ABSTRACT

A proposta da presente revisão de literatura foi estabelecer as evidências existentes sobre etiologia, sinais e sintomas, métodos de diagnóstico e tratamento de dentes gretados. Segundo a American Association of Endodontists (AAE), o termo dente gretado (DG) foi definido como uma fratura em um plano que quebra a continuidade do esmalte e da dentina, sem separação das partes, geralmente no sentido mesiodistal, passando pela superfície oclusal, podendo envolver uma ou ambas as cristas marginais. Essa fratura, por apresentar profundidade e direção desconhecidas, pode se estender até a polpa e/ou ligamento periodontal, levando a um quadro de pulpite reversível, pulpite irreversível, necrose pulpar ou, até mesmo, evoluir para uma fratura completa. Atualmente, os DGs estão relacionados à terceira maior causa de dentes perdidos, após cárie e doença periodontal. Estudos indicam uma falta de consenso entre profissionais sobre como tratar dentes gretados, uma questão clínica relevante, que precisa ser priorizada e esclarecida. Nesse contexto, essa revisão abordou a etiologia, sinais e sintomas, métodos de diagnósti- co e tratamento de dentes gretados (AU)


The purpose of this literature review is to examine the existing evidence regarding etiology, signs, symptoms, methods of diagnosis, and treatment of cracked teeth. According to the American Association of Endodontists (AAE), the term cracked tooth (CT) is defined as "a fracture in a plane that breaks the continuity of the enamel and dentin, without separation of the parts, usually in the mesiodistal direction, passing through the surface occlusal, which may involve one or both of the marginal ridges." Due to its unknown depth and direction, this fracture can extend to the pulp and periodontal ligament, leading to reversible pulpitis, irreversible pulpitis, pulp necrosis, or even progress to a complete fracture. Currently, cracked teeth are related to the third largest cause of missing teeth, after caries and periodontal disease. Studies indicate a lack of consensus among professionals about treating cracked teeth, a clinically relevant issue that needs to be prioritized and clarified. In this context, this review addressed the etiology, signs and symptoms, diagnostic methods, and treatment of cracked teeth (AU).


Subject(s)
Humans , Pulpitis , Dental Pulp Necrosis , Inlays , Specialization , Tooth
8.
Dent. press endod ; 11(2): 63-68, maio-ago.2021.
Article in English | LILACS | ID: biblio-1377951

ABSTRACT

Introdução: Alterações morfológicas na cavidade pulpar e na anatomia radicular podem constituir um desafio ao tratamento endodôntico. A dilaceração pode ser resultado de trauma na dentição decídua, na época da formação das raízes, provocando acentuada curvatura da raiz ou da coroa em um dente permanente. Objetivo: O presente relato de caso teve por objetivo descrever o tratamento endodôntico de um dente #41 com acentuada dilaceração radicular. Radiograficamente, a região periapical do dente #41 mostrou extensa área radiolúcida, sugestiva de osteólise periapical em decorrência de necrose pulpar, que foi confirmada pela ausência de resposta aos testes pulpares. O tratamento endodôntico foi realizado. Conclusão: Após 90 meses de acompanhamento, constatou-se ausência de sinais ou sintomas, e o exame radiográfico forneceu evidências de cicatrização óssea periapical (AU).


Introduction: The morphological changes in the pulp cavity and root anatomy can lead to difficulties in carrying out endodontic treatment. Dilaceration can be the result of trauma in primary dentition, in the root formation phase, provoking accentuated root or crown curvature in a permanent tooth. Objective: The present case report aimed to describe the endodontic treatment of tooth 41 with accentuated root laceration. Radiographically, the periapical region of tooth #41 showed an extensive radiolucent area, suggestive of periapical osteolysis due to pulp necrosis, which was confirmed by the lack of response and pulp tests. Endodontic treatment was realized. Conclusion: The follow-up at 90 months showed no signs or symptoms, and the radiographic examination provided evidence of periapical bone healing.


Subject(s)
Humans , Osteolysis , Tooth, Deciduous , Wound Healing , Dental Pulp Cavity , Incisor , Therapeutics , Wounds and Injuries , Research Report
9.
J Sports Sci ; 39(23): 2674-2682, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34252002

ABSTRACT

The purpose of this study was to examine former Brazilian high-performance volleyball athletes' perspectives on life skills learning and transfer through their experiences in sport. This qualitative study involved a narrative approach through composite vignettes. The creation of the composite vignettes included the most relevant life events and participants' perspectives through their accounts of the experience transformed in one unique voice. Participants were five former Brazilian high-performance volleyball athletes. Data were collected through rappaport timeline and semi-structured interviews. Findings showed athletes were able to learn and transfer life skills throughout their careers and later in life through an implicit approach to life skills development and transfer. The trials and tribulations of high-performance sport were, in these cases, used as life lessons that transformed into life skills used in athletes' lives beyond sport. Moving forward, more research is needed to understand the high-performance sport's role in life skills transfer and its implication for athletes' development across socio-cultural contexts.


Subject(s)
Volleyball , Athletes , Brazil , Humans , Learning , Qualitative Research
10.
Braz Oral Res ; 35: e060, 2021.
Article in English | MEDLINE | ID: mdl-33909867

ABSTRACT

This study aimed to describe the morphometric relationship of root canal orifices on the pulp floor in the presence/absence of mesiobuccal second canal (MB2) in the maxillary first molars and other aspects of its internal anatomy. Sixty-two maxillary first molars were scanned by micro-CT. The presence of the MB2 canal was verified. The distance between the center points of the MB1, MB2, distobuccal (DB), and palatal (P) canal orifices on the pulp floor were measured (MB1-MB2, MB1-DB, MB2-DB, MB1-P, and DB-P). The MB1-P to DB-P ratio was calculated. The distances between the anatomic apex and the MB1 and MB2 apical foramina were measured. The length of the band-shaped isthmus was also measured. Student's t-test was applied to verify the association between the presence of an MB2 canal, the interorifice distances, and the ratio of the MB1-P to DB-P distance (α = 5%). The MB2 canal was present in 43 roots (69.35%). Statistics showed significant differences when MB2 was present for the largest MB1-P distance (p < 0.05) and higher values for the MB1-P to DB-P ratio (p < 0.05). A band-shaped isthmus was detected in 25.8% of MB roots. The mean distance from the apical foramen to the isthmus floor ranged from 1.74 for MB1 canals to 1.42 for MB2 canals. Canal orifice distances on the pulp floor may predict the presence of MB2 canals. There was a high incidence of isthmus, accessory canals, and apical delta in the critical apical zone in MB roots of maxillary first molars.


Subject(s)
Maxilla , Tooth Root , Dental Pulp Cavity/diagnostic imaging , Humans , Maxilla/diagnostic imaging , Molar/diagnostic imaging , Tooth Root/diagnostic imaging , X-Ray Microtomography
11.
J Endod ; 47(7): 1157-1165, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33901544

ABSTRACT

INTRODUCTION: The present study aimed to describe an in vitro study model to investigate root surface strain (RSS) and its correlation with the initiation/propagation of microcracks during different endodontic procedures. METHODS: Four lower human incisors extracted microcrack free were selected by micro-computed tomographic imaging. Two strain gauges were bonded to the root surface of each incisor. Then, the teeth were prepared to reproduce the periodontal ligament artificially. The gauges were attached to a data acquisition system. The RSS was recorded during the entire endodontic procedure, which consisted of accessing the endodontic cavity, cleaning, shaping preparation with an Mtwo rotary system (VDW, Munich, Germany), and filling with a standardized technique. Each incisor was submitted to a different retreatment protocol and supplementary cleaning method as follows: (1) Reciproc (RC, VDW) + Flatsonic (FS; Helse, Santa Rosa de Viterbo, Brazil), (2) RC + XP-endo Finisher (XPF; FKG Dentaire, La Chaux-de-Fonds, Switzerland), (3) Mtwo retreatment (MR) + FS, and (4) MR + XPF. Finally, the teeth were rescanned to establish the postoperative microcrack formation by 2 well-trained and blinded examiners. RESULTS: The maximum and minimum RSS values were -120 and 510 microstrains, respectively, for all of the files. RC showed the highest RSS values during endodontic retreatment compared with MR. FS demonstrated a higher variation between the minimum and maximum RSS than XPF. No microcracks were observed in the specimens. CONCLUSIONS: This preliminary study proposed an experimental model that would combine 2 methods to evaluate the effects of endodontic systems on dentin. Although strain gauges would provide data on the stresses created, the pre- and postoperative evaluation of micro-computed tomographic images would enable microcrack formation to be determined.


Subject(s)
Dental Pulp Cavity , Root Canal Preparation , Brazil , Humans , Retreatment , X-Ray Microtomography
12.
Braz Dent J ; 32(1): 104-110, 2021.
Article in English | MEDLINE | ID: mdl-33913996

ABSTRACT

These case reports aimed to describe the management of lateral perforation in the middle cervical third of the root in two maxillary incisors with pulp canal calcification using Bio-C Repair, with safe and viable clinical treatment strategies. Digital radiographic exams were obtained with different angles and analyzed using different filters. Cone-beam computed tomography (CBCT) images were requested to show the actual position of the canal, location of the perforation, and guide the strategic planning of the case. Subsequently, cavity access was prepared with the aid of dental operating microscopy. After perforation was identified, granulation tissue was removed and the original canal was identified and then dressed with calcium hydroxide. In the second visit, the perforation was filled with Bio-C Repair and the canal system filled with gutta-percha points and a root canal sealer (Bio-C Sealer). The teeth were restored with glass fiber post, 4 mm beyond the perforation level, and provisory crowns. Both teeth treated as described above were functional and asymptomatic with a 1-year clinical and radiographic assessment. The Bio-C Repair is suggested as a new cement option for the management of lateral canal perforations, with effective results as observed after a one-year follow-up.


Subject(s)
Root Canal Filling Materials , Root Canal Preparation , Calcium Hydroxide , Dental Pulp Cavity , Gutta-Percha , Humans , Root Canal Obturation
13.
J Clin Exp Dent ; 13(2): e112-e118, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33574995

ABSTRACT

BACKGROUND: This study aimed to evaluate the centralization and transportation of ProTaper Gold (PTG) rotary system and Reciproc Blue (RB) reciprocating system in curved canals, by using micro-CT. MATERIAL AND METHODS: Twenty extracted mandibular molars were previously scanned by using the SkyScan 1174 microtomograph to select the Vertucci IV anatomic type. The specimens were divided into two groups (n=10) according to the mechanized system used to prepare the root canals. The teeth were scanned by micro-CT to calculate the increase volume, percentage of dentin removed, remaining dentin thickness, structure model index (SMI), degree of transportation and centering ability of root canals. The Student's t test was used to evaluate differences between PTG and RB in each measurement evaluated. RESULTS: No significant differences were found between the groups in the increase of the total root canal and apical volume; percentage of dentin removed after preparation; SMI of the mesiolingual canal; degree of transportation of the canal and centering ability of the cervical and middle thirds (P>0.05). There were significant differences in the mesiobuccal canal in SMI and in the centering ability of the apical third (P<0.05). Concerning the remaining dentin thickness, there was also no significant diferences between the groups, except for some regions were RB was observed to have a superior cutting capacity (P<0.05). CONCLUSIONS: Both systems were efficient and safe for performing preparation of the moderately curved root canals of mandibular molars. RB instruments produced more circular and better centralized canals in the apical third of the mesiobuccal canal, with superior cutting action when compared with PTG instruments. Key words:Nickel-titanium instrument, heat treatment, micro-computed tomography, canal transportation.

14.
Braz. dent. j ; Braz. dent. j;32(1): 104-110, Jan.-Feb. 2021. graf
Article in English | LILACS, BBO - Dentistry | ID: biblio-1180730

ABSTRACT

Abstract These case reports aimed to describe the management of lateral perforation in the middle cervical third of the root in two maxillary incisors with pulp canal calcification using Bio-C Repair, with safe and viable clinical treatment strategies. Digital radiographic exams were obtained with different angles and analyzed using different filters. Cone-beam computed tomography (CBCT) images were requested to show the actual position of the canal, location of the perforation, and guide the strategic planning of the case. Subsequently, cavity access was prepared with the aid of dental operating microscopy. After perforation was identified, granulation tissue was removed and the original canal was identified and then dressed with calcium hydroxide. In the second visit, the perforation was filled with Bio-C Repair and the canal system filled with gutta-percha points and a root canal sealer (Bio-C Sealer). The teeth were restored with glass fiber post, 4 mm beyond the perforation level, and provisory crowns. Both teeth treated as described above were functional and asymptomatic with a 1-year clinical and radiographic assessment. The Bio-C Repair is suggested as a new cement option for the management of lateral canal perforations, with effective results as observed after a one-year follow-up.


Resumo O presente relato de caso teve como objetivo descrever o manejo da perfuração lateral no terço médio cervical da raiz em dois incisivos superiores com calcificação pulpar utilizando o Bio-C Repair, com estratégias de tratamento clínico seguras e viáveis. Radiografias digitais foram obtidas em diferentes ângulos e analisadas com diferentes filtros. Imagens de tomografia computadorizada de feixe cônico (TCFC) foram solicitadas para mostrar a real posição do canal e a localização da perfuração, e orientar o planejamento estratégico do caso. Posteriormente, o acesso à cavidade foi preparado com auxílio de microscopia cirúrgica. Após a identificação da perfuração, o tecido de granulação foi removido, o canal original foi identificado e, em seguida, recebeu medicação intracanal à base de hidróxido de cálcio. Na segunda visita, a perfuração foi selada com Bio-C Repair e o sistema de canais obturado com cones de guta-percha e cimento endodôntico (Bio-C Sealer). Os dentes foram restaurados com pino de fibra de vidro, 4 mm além do nível da perfuração, e coroas provisórias. Ambos os dentes tratados conforme descrito acima se mostraram funcionais e assintomáticos na avaliação clínica e radiográfica de 1 ano. O Bio-C Repair é sugerido como uma nova opção de cimento endodôntico para o manejo de perfurações laterais, com resultados efetivos observados após um ano de acompanhamento.


Subject(s)
Humans , Root Canal Filling Materials , Root Canal Preparation , Root Canal Obturation , Calcium Hydroxide , Dental Pulp Cavity , Gutta-Percha
15.
Nanotechnology ; 32(14): 145707, 2021 Apr 02.
Article in English | MEDLINE | ID: mdl-33326949

ABSTRACT

As different low-dimensional materials are sought to be incorporated into microelectronic devices, graphene integration is dependent on the development of band gap opening strategies. Amidst the different methods currently investigated, application of strain and use of electronic quantum confinement have shown promising results. In the present work, epitaxial graphene nanoribbons (GNR), formed by surface graphitization of SiC (0001) on crystalline step edges, were submitted to photochemical chlorination. The incorporation of Cl into the buffer layer underlying graphene increased the compressive uniaxial strain in the ribbons. Such method is a promising tool for tuning the band gap of GNRs.

16.
Braz. oral res. (Online) ; 35: e060, 2021. tab, graf
Article in English | LILACS, BBO - Dentistry | ID: biblio-1249378

ABSTRACT

Abstract: This study aimed to describe the morphometric relationship of root canal orifices on the pulp floor in the presence/absence of mesiobuccal second canal (MB2) in the maxillary first molars and other aspects of its internal anatomy. Sixty-two maxillary first molars were scanned by micro-CT. The presence of the MB2 canal was verified. The distance between the center points of the MB1, MB2, distobuccal (DB), and palatal (P) canal orifices on the pulp floor were measured (MB1-MB2, MB1-DB, MB2-DB, MB1-P, and DB-P). The MB1-P to DB-P ratio was calculated. The distances between the anatomic apex and the MB1 and MB2 apical foramina were measured. The length of the band-shaped isthmus was also measured. Student's t-test was applied to verify the association between the presence of an MB2 canal, the interorifice distances, and the ratio of the MB1-P to DB-P distance (α = 5%). The MB2 canal was present in 43 roots (69.35%). Statistics showed significant differences when MB2 was present for the largest MB1-P distance (p < 0.05) and higher values for the MB1-P to DB-P ratio (p < 0.05). A band-shaped isthmus was detected in 25.8% of MB roots. The mean distance from the apical foramen to the isthmus floor ranged from 1.74 for MB1 canals to 1.42 for MB2 canals. Canal orifice distances on the pulp floor may predict the presence of MB2 canals. There was a high incidence of isthmus, accessory canals, and apical delta in the critical apical zone in MB roots of maxillary first molars.


Subject(s)
Tooth Root/diagnostic imaging , Maxilla/diagnostic imaging , Dental Pulp Cavity/diagnostic imaging , X-Ray Microtomography , Molar/diagnostic imaging
17.
Dent. press endod ; 10(3): 81-87, Sept-Dec.2020. Ilus
Article in English | LILACS | ID: biblio-1348049

ABSTRACT

Introdução: A identificação de possíveis variações anatômicas é decisiva para o correto diagnóstico e planejamento da terapia endodôntica. Objetivo: Relatar o tratamento endodôntico de um dente #37, no qual foi identificado um terceiro canal na raiz mesial (canal mesio-mediano, CMM). Caso clínico: Dente #37 com diagnóstico de pulpite irreversível sintomática, foi encaminhado para realizar tratamento endodôntico. Durante o acesso coronário, e com auxílio de microscópio operatório (MO), foram identificadas trincas coronárias. Foi solicitada uma tomografia computadorizada de feixe cônico (TCFC), a partir da qual foi descartada a presença de trinca radicular. A TCFC possibilitou, também, identificar a presença de um terceiro canal na raiz mesial, localizado entre os canais mesiovestibular e mesiolingual. O tratamento endodôntico foi executado pelo sistema reciprocante WaveOne GOLD. A solução irrigadora de escolha para o preparo químico-mecânico foi o hipoclorito de sódio a 5,25%. Imediatamente antes da obturação, os canais foram irrigados com EDTA a 17%, para auxiliar na remoção da smear layer e, em seguida, foi realizada nova irrigação com hipoclorito de sódio a 5,25%. Os canais foram secos com pontas de papel absorvente e obturados pela técnica de onda contínua de condensação. Resultados: Os canais radiculares do dente #37 foram devidamente instrumentados e obturados. A paciente não apresentou qualquer sintomatologia pós-operatória, sendo encaminhada para a reabilitação protética final. Conclusão: A TCFC e o microscópio operatório foram decisivos para o correto planejamento do caso, tanto em relação à trinca observa- da quanto à detecção do canal mesiomediano (AU).


Introduction: Identification of possible anatomical variations is crucial for the correct diagnosis and planning of endodontic therapy. Objective: To report the endodontic treatment of tooth #37, in which a third canal was located in the mesial root (middle mesial canal - MMC). Methods: Tooth #37 was diagnosed with symptomatic irreversible pulpitis and referred for endodontic treatment. Coronary cracks were found during coronal access using a dental operating microscope (DOM). A cone-beam computed tomography (CBCT) was requested. CBCT revealed cracks involving the pulp chamber floor and a third root canal in the mesial root, between the mesiobuccal and the mesiolingual canals. Endodontic treatment was performed with the WaveOne GOLD reciprocating system. The chemical-mechanical preparation was performed with 5.25% sodium hypochlorite and 17% EDTA to remove the smear layer, followed by another irrigation with sodium hypochlorite. The canals were dried with absorbent paper points. The root canal obturation was performed with the continuous wave of condensation technique. Results: The root canals of tooth #37 were correctly instrumented and obturated. The patient did not present with any postoperative symptoms, and was referred for final prosthetic rehabilitation. Conclusion: CBCT and DOM were paramount for the correct planning of the case, as regards the presence of cracks and the detection of the middle mesial canal (AU).


Subject(s)
Pulpitis , Cone-Beam Computed Tomography , Molar , Therapeutics , Microscopy
18.
Dent. press endod ; 10(3): 36-42, Sept-Dec.2020. Ilus
Article in English | LILACS | ID: biblio-1344767

ABSTRACT

Introdução: Pinos intrarradiculares são recomendados para melhorar a retenção de coroas artificiais e distribuir forças intrabucais ao longo da raiz. Se o espaço criado pela remoção parcial da obturação não for preenchido adequadamente, pode ocorrer uma infiltração maciça de microrganismos da cavidade bucal. Objetivo: O objetivo do presente estudo foi avaliar a eficácia contra a infiltração bacteriana de uma barreira intracanal colocada diretamente sobre o remanescente da obturação do canal radicular, após o preparo de espaço para o pino. Métodos: Setenta e dois dentes humanos unirradiculares foram instrumentados, obturados e divididos aleatoriamente em três grupos experimentais e dois grupos controle. O grupo 1 não recebeu tratamento adicional após a obturação e o preparo do espaço, enquanto os Grupos 2 e 3 receberam uma barreira composta por material de selamento temporário com 1,0 e 2,0 mm de espessura, respectiva- mente. Uma cultura de Enterococcus faecalis foi inoculada nos espaços preparados para receber o pino intrarradicular, a cada três dias, por um período de 60 dias. A infiltração foi avaliada diariamente pela turbidade do meio de cultura. Resultados e Conclusão: Houve infiltração bacteriana nos três grupos experimentais, sendo significativamente maior e ocorrendo mais rapidamente no G1 (p<0,05), em comparação aos G2 e G3. Houve infiltração em todos os grupos controles positivos; porém, nenhuma infiltração foi observada nos grupos controles negativos. Não foi encontrada diferença significativa (p>0,05) entre o G2 e o G3, em relação à taxa e ao período de infiltração. Pode-se concluir que a barreira reduziu a incidência de infiltração e atrasou o tempo de ocorrência (AU).


Introduction: Intraradicular posts are recommended to improve the retention of artificial crowns and to distribute intraoral forces along the root. If the space created by partially removing the obturation is not adequately filled, it can lead to a massive infiltration of microorganisms from the oral cavity. Aim: The aim of this study was to assess the influence on bacterial infiltration of an intracanal barrier placed directly over the remaining root canal filling following post space preparation. Material and Methods: Seventy-two human single-rooted teeth were instrumented, filled, and then randomly divided into three experimental groups and two control groups. Group 1 received no additional treatment after filling and post space preparation, whereas Groups 2 and 3 received a barrier composed of temporary sealing material 1.0- and 2.0-mm thick, respectively. A culture of Enterococcus faecalis was inoculated into the spaces prepared to receive the intraradicular post, every three days over a 60-day period. Infiltration was evaluated daily by observing the turbidity of the culture medium. Results and Conclusion: Bacterial infiltration was found in all three experimental groups, but was significantly greater and occurred more quickly in G1 (p < 0.05), compared with G2 and G3. Infiltration was observed in all positive controls, whereas no infiltration was found in the negative controls. No significant difference (p > 0.05) was found between G2 and G3, regarding the rate and time frame of infiltration. It can be concluded that the barrier reduced the incidence of infiltration, and delayed the time of occurrence (AU).


Subject(s)
Humans , Root Canal Obturation , Enterococcus faecalis , Dental Pins , Efficacy , Crowns
19.
J Clin Exp Dent ; 12(5): e514-e518, 2020 May.
Article in English | MEDLINE | ID: mdl-32509236

ABSTRACT

Root fractures resulting from dental trauma involve dentin, cementum and pulp. The present study aimed to demonstrate the importance of cone-beam computed tomography (CBTC) and bioceramics in the correct planning and intervention of a horizontal root fracture case in tooth 11 with late treatment in an 18-year-old patient. Clinical and radiographic examinations revealed tooth displacement, pain on vertical percussion and images suggestive of a horizontal root fracture. Pulp necrosis was diagnosed and CBTC was requested for treatment planning. Subsequently, endodontic treatment was performed using a bioceramic apical plug. A 2-year follow-up indicated the absence of root resorption and normal periodontal and periapical tissues. It was concluded that endodontic treatment associated with the use of bioceramics and the aid of CBTC is an effective therapeutic option in cases of permanent horizontal root fractures. Key words:Bioceramics, Cone-beam computed tomography, dental Injuries, root fracture.

20.
J Clin Exp Dent ; 12(5): e519-e522, 2020 May.
Article in English | MEDLINE | ID: mdl-32509237

ABSTRACT

Rehabilitation of patients through implants in areas with severe bone resorption in the posterior mandible is a challenge in implant dentistry. In this context, extra short implants configure a treatment option for this type of patient, as they can avoid increased financial cost, treatment time and patient morbidity. The present study evaluated the marginal bone stability in individualized extra-short implants for masticatory function in the posterior mandible. Using digitized periapical radiographs of 13 extra-short implants performed on 7 patients. The mesial and distal regions of each implant were selected, from the bone crest to the region parallel to the apex, and the bone stability of this crest was measured using the Image J software immediate T1 and 1 year after rehabilitation (T2). The height of the bone crest remained stable, showing no statistically significant difference between T1 and T2 (p> 0.005) for both the mesial bone crest and the distal bone crest in individual or united crowns rehabilitation. Marginal bone stability was observed in extra short implants, corroborating the biological and biomechanical stability of these implants presented in the literature. Despite the limited sample size and proservation time, extra-short implants are predictive treatment options for patients with severe bone atrophy in the posterior mandible. Key words:Extra-short implants, marginal bone loss, mandibular bone atrophy.

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