Reabilitação oral com próteses parciais removíveis após restabelecimento de dimensão vertical de oclusão e tratamento multidisciplinar: relato de caso / Oral rehabilitation with removable partial dentures after restoration of the vertical dimension of occlusion and multidisciplinary treatment: case report

As próteses parciais removíveis (PPRs) são uma alternativa de tratamento viável na prática clínica para reabilitar arcos parcialmente desdentados. Entretanto, o planejamento dessas próteses e preparo bucal prévio são frequentemente negligenciados. O presente artigo tem como objetivo relatar o caso clínico de uma reabilitação oral com PPRs superior e inferior após abordagem multidisciplinar, de modo a enfatizar as fases de um planejamento criterioso e de preparo prévio dos dentes pilares, visando o sucesso e a longevidade da reabilitação. Paciente do sexo masculino de 57 anos de idade compareceu à clínica da Faculdade de Odontologia de Bauru, Universidade de São Paulo, queixando-se da estética de seu sorriso e de algumas ausências dentárias. O indivíduo utilizava uma PPR provisória inferior insatisfatória e apresentava perda de dimensão vertical de oclusão (DVO). Após o exame clínico, radiográfico e estudo do caso em articulador semi-ajustável, realizou-se o planejamento com abordagens restauradoras, endodônticas, periodontais e protéticas. Após tratamento periodontal, foi realizada endodontia dos elementos 12, 15 e 47, confecção de núcleos e coroas nos dentes 12 e 15, restauração a nível gengival para apoio residual no dente 47, restaurações nos dentes 11, 13, 22, 24 e 44 e, por fim, a confecção das PPRs superior e inferior. A abordagem multidisciplinar utilizada neste caso clínico viabilizou o restabelecimento da DVO e possibilitou o sucesso da reabilitação protética(AU)

Removable partial dentures (RPDs) are a viable treatment alternative in clinical practice to rehabilitate partially edentulous arches. However, the planning of these dentures and prior oral preparation are often neglected. This article aims to report the clinical case of an oral rehabilitation with upper and lower RPDs after a multidisciplinary approach, to emphasize the phases of careful planning and prior preparation of the abutment teeth, aiming at the success and longevity of the rehabilitation. A 57-year-old male patient came to the clinic of the Bauru School of Dentistry, University of São Paulo, complaining about the esthetics of his smile and some missing teeth. The subject was using an unsatisfactory lower provisional prosthesis and had a loss of vertical dimension of occlusion (OVD). After the clinical and radiographic examination and the case study in a semi-adjustable articulator, planning was carried out with restorative, endodontic, periodontal and prosthetic approaches. After periodontal treatment, endodontics were performed on elements 12, 15 and 47, creation of cores and crowns on teeth 12 and 15, restoration at the gingival level for residual support on tooth 47, restorations on teeth 11, 13, 22, 24 and 44 and, finally, the making of the upper and lower PPRs. The multidisciplinary approach used in this clinical case enabled the restoration of the OVD and enabled the success of the oral rehabilitation(AU)

Reabilitação estética anterior em abordagem multidisciplinar: relato de caso / Aesthetic rehabilitation in a multidisciplinary approach: case report

A estética tem um papel importante na aceitação e autoestima das pessoas e, em virtude disso, os pacientes buscam cada dia mais ter um sorriso harmonioso. As reabilitações estéticas devem envolver um planejamento completo, atrelando função e estética, avaliando tamanho dos dentes, perfil e alturas gengivais, altura do sorriso e corredor bucal. Por conta disso, a odontologia nos permite uma série de abordagens terapêuticas diferentes que chegam a resultados satisfatórios para o paciente. Sendo assim, o presente trabalho tem como objetivo descrever um relato de caso de uma paciente com queixa estética do seu sorriso devido à diferentes tonalidades, formas e tamanhos dos dentes. Após anamnese, exame clínico e radiográfico, o plano de tratamento proposto foi de harmonizações periodontal com aumento de coroa e enxerto gengival, além de coroas em cerâmicas de dissilicato de lítio. Dentro desse contexto, mostra-se que uma abordagem multidisciplinar para reabilitação estética e funcional do sorriso é fundamental, a qual nos proporciona equilíbrio e naturalidade entre estética branca e vermelha no resultado do tratamento reabilitador(AU)

Aesthetics plays an important role in people's acceptance and self-esteem and, as a result, patients increasingly seek to have a harmonious smile. Aesthetic rehabilitations must involve a complete planning, linking function and aesthetics, evaluating tooth size, gingival profile and heights, smile height and buccal corridor. Because of this, dentistry allows us a series of different therapeutic approaches that reach satisfactory results for the patient. Therefore, the present work aims to describe a case report of a patient with an aesthetic complaint of her smile due to different shades, shapes and sizes of teeth. After anamnesis, clinical and radiographic examination, the proposed treatment plan was periodontal harmonization with crown augmentation and gingival graft, in addition to lithium disilicate ceramic crowns. Within this context, it is shown that a multidisciplinary approach to the aesthetic and functional rehabilitation of the smile is fundamental, which provides us with balance and naturalness between white and red aesthetics in the result of the rehabilitation treatment(AU)

Benefícios do planejamento digital para cirurgias periodontais estéticas: relato de caso / Benefits of digital planning for esthetic periodontal surgeries: case report

Sorriso gengival é comumente conhecido pela exposição excessiva das gengivas ao sorrir, acarretando assim na diminuição das coroas dos elementos. No que tange a etiologia dessa condição, ela se apresenta de maneiras diversas e sua identificação é fundamental para o desenvolvimento de um plano de tratamento eficaz. O planejamento clínico pode ser feito usando uma abordagem dinâmica e digital do sorriso, como softwares, exames de imagem, modelos virtuais 3D e guias cirúrgicos, melhorando a qualidade e precisão do tratamento, oferecendo diversos benefícios aos pacientes. Sendo assim esse estudo teve como objetivo demonstrar a importância dos processos digitais no planejamento e correção do sorriso gengival. Paciente queixou-se da desproporção do sorriso, caracterizado por coroas curtas nas regiões de pré-molares e incisivos ligadamente com a exposição excessiva da gengiva ao sorrir. Após estudos clínicos e de imagem, a etiologia foi diagnosticada como erupção passiva alterada, tipo I (fenótipo espesso). O tratamento de escolha foi o remodelamento gengival associado à osteotomia e osteoplastia obtendo assim uma maior precisão no tratamento, sendo confeccionado um guia cirúrgico duplo. Sendo assim, é possível contemplar que o planejamento digital permite uma maior previsibilidade da execução, compatibilidade em relação a expectativa do paciente e profissional, além da total individualização do caso, tornando os resultados mais favoráveis e exatos e minimizando as chances de iatrogenias(AU)

Gummy smile is commonly known for exposing the gums to the smile, thereby increasing the crowns elevation of the elements. Regarding a condition, it presents itself in different ways and its identification is fundamental for the development of a treatment plan. The clinician can be done using a dynamic and digital approach to image treatment, such as software, imaging exams, various 3D virtual models and elaborate guides, improving the quality and precision of treatment, offering benefits to patients. Therefore, this study aimed to demonstrate the importance of digital processes in planning and correcting the gummy smile. Patient complained of disproportion of the smile, facing the regions of premolar crowns and incisors of the smile, facing the exposure of the gingiva when smiling. After clinical and imaging exams, the diagnostic studies were diagnosed as passive eruption, type I (phenotype and specific). The choice of choice was remodeling associated with surgery treatment and surgery treatment, thus providing a greater precision in the treatment, being a double guide elaborated. Therefore, it is possible that the digital is possible a predictability of execution, compatibility in relation to patient and professional care, in addition to the greater possibility of individualization planning than it allows, making the results more planned as possibilities and exactly the iatrogenic(AU)

Reabilitação estética com facetas e coroas cerâmicas em dissilicato de lítio: relato de caso / Aesthetic rehabilitation with ceramic facets and crowns in lithium disilicate: case report

Introdução: A procura pela estética do sorriso é crescente na Odontologia, pois, muitas vezes um sorriso alinhado e periodonto saudável não são o bastante. A cerâmica odontológica apresenta-se como uma ótima possibilidade restauradora, visto o avanço das técnicas de adesão entre o substrato dentário e as cerâmicas, torna-se mais previsível o resultado com este tipo de reabilitação. Objetivo: O presente artigo tem como objetivo descrever um caso clínico com envolvimento de diversos níveis de desgaste dentário para reabilitação estética com cerâmica de dissilicato de lítio. Relato de caso: Paciente 36 anos, gênero feminino, apresentava insatisfação com seu sorriso devido a forma e a alteração de cor dos seus dentes superiores anteriores e pré-molares. O plano de tratamento consistiu em realizar a troca da coroa metalocerâmica por coroa total cerâmica da unidade 14, coroa total cerâmica nas unidades 11, 21 e 22, facetas cerâmicas nas unidades 15, 13, 12, 23, 24 e 25, osteotomia e gengivoplastia das regiões de 2º prémolar superior esquerdo ao 2º pré-molar superior direito, clareamento dental caseiro da arcada inferior e placa oclusal superior de proteção. O material de escolha para a resolução do caso clínico foi a cerâmica vítrea reforçada à base de dissilicato de lítio, pois, possui um índice de refração de luz semelhante à estrutura dentária, sem interferência significativa da translucidez, além de ser passível de cimentação adesiva por se tratar de uma cerâmica ácido sensível e o tamanho do cristal e a sua disposição favorecem o aumento das propriedades mecânicas da restauração. Conclusão: O plano de tratamento realizado permitiu o restabelecimento da função e estética, com reprodução das características dos dentes naturais e promoção da jovialidade e da harmonia no sorriso(AU)

Introduction:The demand for smile aesthetics is growing in Dentistry, because, often a smile aligned and healthy periodontium are not enough. Dental ceramics, presented as an excellent restorative possibility, since the advancement of adhesion techniques between the dental substrate and the ceramics, becomes more predictable the result with this type of rehabilitation. Objective: This article aims to describe a clinical case involving several levels of dental wear for aesthetic rehabilitation with ceramics. Case Report: A 36-year-old female patient presented dissatisfaction with her smile due to the shape and color alteration of her anterior and premolar upper teeth. The treatment plan consisted of exchanging the metal-ceramic crown for the total ceramic crown of unit 14, total ceramic crown in units 11, 21 and 22, ceramic veneers in units 15, 13, 12, 23, 24 and 25, osteotomy and gingivoplasty of the regions from 2nd left upper premolar to 2nd right upper premolar, home tooth whitening of the lower arch and upper occlusal plate of protection. The material of choice for the resolution of the clinical case was the glass ceramic reinforced on the basis of lithium disilicate because it has a refractive index of light similar to the dental structure, without significant interference of translucency, besides being liable to adhesive cementation because it is a sensitive acid ceramic and the size of the crystal and its disposition favor the increase of the mechanical properties of the restoration. Conclusion: The treatment plan performed allowed the restoration of function and aesthetics, with reproduction of the characteristics of natural teeth and promotion of joviality and harmony in the smile(AU)

Evaluation of the occlusal contact area of molar dental implants comparing two different thicknesses (16 µm and 200 µm) of articulating occlusal papers and forces (200 and 250 N): a pivot in vitro study

Introduction: The goal of this pilot study was to evaluate the differences between checking occlusion on implants crowns using 16 or 200 µm thickness of articulating occlusal paper, and to compare the stained occlusal area between the groups after bite forces of 200 and 250 N. Methods: It was included 10 casts of articulated-type IV gypsum, 10 NiCr crowns, articulating occlusal papers (16 µm and 200 µm thick), and a compression test machine. Compressive forces (200 and 250 N.mm) were applied on models, to check the occlusal contact area of fixed and cemented crowns. The contact areas on the crowns were measured through images obtained by the scanning electron microscope. Statistical tests were performed considering the significant level of 5% (p≤0.05). Results: The stains found using 200 µm of articulating paper were higher than those with 16 µm, independent of the force applied. However, the stains obtained in lower teeth with different strengths (200 and 250N) marked with 16 µm articulating paper were not possible to score. The articulating paper variable had significant statistical results (p=0.002), while the variables force (p=0.443) and articulating paper-force interaction (p=0.607) were not significant. The mean area found in staining using the 200 µm and 16 µm papers was, respectively, 8.3380 mm2 and 3.4759 mm2. Conclusion: It was possible to confirm that 200 µm of articulating occlusal paper showed better and significant results to stain the occlusal area, permitting a more accurate adjustment independent of the force applied.

Fracture strength and failure load of CAD/CAM fabricated endocrowns performed with different designs

Aim: Endocrown restorations are commonly used to rehabilitate endodontically treated posterior teeth and their use is well-founded in these cases. However, to date, there is little scientific evidence of their behavior in anterior teeth. The aim of this in vitro study was to evaluate the compressive strength of upper central incisors teeth, restored with glass-ceramic total crowns by the conventional anatomical core technique, and compare them to teeth restored with endocrowns with and without the presence of ferrule. Methods: Thirty teeth were randomly distributed into three groups: GE2 - endocrown group with 2 mm ferrule, GE0 - endocrown group without a ferrule, and GC - conventional crown with intraradicular post group. Crowns were cemented and teeth submitted to the 45o compression test until the fracture happened. Fractured specimens were analyzed to determine the fracture pattern. Descriptive analysis of the variables was performed and one-way analysis of variance was utilized to analyze the data for significant differences at p < 0.05. Results: The results of the control group (284.5 ± 201.05N) showed the highest fracture resistance value, followed by the 2mm group (274.54 ± 199.43N) and by the 0mm group (263.81 ± 80.05N). There was no statistically significant difference between all the groups (p = 0.964). Conclusions: The absence of a cervical enamel necklace favored a debonding of the pieces and endodontically treated anterior teeth could be restored with endocrown, which could be considered a conservative and viable treatment option

Fit of metal-ceramic crowns: effect of coping fabrication method and veneering ceramic application

Aim: To evaluate the influence of cobalt-chromium (Co-Cr) coping fabrication methods and ceramic application on the marginal and internal fit of metal-ceramic crowns. Methods: Co-Cr copings for metal-ceramic crowns were prepared by lost wax casting or CAD-CAM machining of sintered blocks. The fit was analyzed using the silicone replica technique at four assessment points: marginal gap (MG), axial wall (AW), axio-occlusal (AO) angle, and central occlusal (CO) wall. After the initial analysis, the copings were ceramic-veneered with the layering technique, and the fit was again determined. Data were statistically analyzed by paired and unpaired Student's-t test (α=0.05). Results: Marginal and internal fit before ceramic application according to the coping manufacturing method showed significant differences only at CO (p < 0.001), with milled copings (137.98±16.71 µm) showing higher gap values than cast copings (112.86±8.57 µm). For cast copings, there were significant differences at MG (before 109.13±8.79 µm; after 102.78±7.18 µm) and CO (before 112.86±8.57 µm; after 104.07±10.63 µm) when comparing the fit before and after ceramic firing. For milled copings, there was significant difference only at AO (before 116.39±9.64 µm; after 108.54±9.26 µm). Conclusion: This study demonstrated that the coping fabrication method influenced the internal fit. Ceramic firing maintained or improved the fit of the metal-ceramic crowns. The marginal discrepancy of all restorations, before and after ceramic firing, can be considered clinically acceptable

Técnica endocrown como alternativa restauradora para dentes tratados endodonticamente: relato de caso clínico / Endocrown technique as a restorative alternative for endodontically treated teeth: a case report

Este trabalho teve como objetivo apresentar um relato de caso clínico de uma restauração do tipo coroa endocrown cerâmica em um dente molar tratado endodonticamente. Paciente com 45 anos de idade, sexo feminino, procurou a clínica do Centro Universitário da Serra Gaúcha (FSG) relatando a necessidade de reabilitação protética no primeiro molar inferior do lado esquerdo. Com base no exame radiográfico e exame clínico foi constatado um primeiro molar inferior do lado esquerdo com tratamento endodôntico satisfatório, mas uma extensa destruição coronária. Após a aprovação da paciente e indicações para a utilização da técnica, optou-se pela confecção de uma coroa endocrown em cerâmica reforçada por dissilicato de lítio. Foi realizado o preparo do remanescente dentário, envolvendo a câmara pulpar, com ângulos arredondados e expulsivos e, após a moldagem do mesmo com silicone de adição, utilizando a técnica simultânea e duplo fio. O provisório foi realizado com resina quimicamente ativada na cor 62 e, na sessão seguinte a coroa endocrown foi ajustada e polida. Após receber o protocolo de condicionamento adequado da peça, a mesma foi cimentada com cimento autopolimerizável Multilink N. Pode-se concluir que a alternativa restauradora Endocrown é um tratamento conservador e favorável para dentes com extensa destruição coronária, permitindo adequada estética e função(AU)

This study aimed to present a clinical case report of an endocrown ceramic crown restoration in na endodontically treated molar tooth. A 45-year-old female patient sought the clinic at the Centro Universitário da Serra Gaúcha (FSG), reporting the need for prosthetic rehabilitation on the lower left first molar. Based on the radiographic and clinical examination, the first molar presented satisfactory endodontic treatment, but extensive coronary destruction. After the approval of the patient and indications for the use of the technique, it was decided to make an endocrown with reinforced ceramic by lithium disilicate. The remaining tooth was prepared, involving the pulp chamber, with rounded and expulsive angles and, after the impression with silicone using the simultaneous and double wire technique was taken. The provisional was made with chemically activated resin in color 62 and, in the following session, the endocrown crown was adjusted and polished. After receiving the proper conditioning protocol, it was lutted with Multilink N self-curing cement. It can be concluded that the Endocrown restorative alternative is a conservative and favorable treatment for teeth with extensive coronary destruction, allowing adequate aesthetics and function(AU)

Initial establishment of digital reference standardized crown models of the primary teeth / 北京大学学报(医学版)

OBJECTIVE@#To explore the construction process of the digital reference crown models, and to initially establish the digital reference crown models of the primary teeth to lay the foundation for the establishment of the standardized crown models and the future related applications of computer-aided design/computer-aided manufacture (CAD/CAM) technology to pediatric dentistry.@*METHODS@#This study randomly selected children who were caries free, aged from 4 to 5 years in several kindergartens of Haidian District of Beijing.Plaster dental models were made for the children after taking complete impressions.The digital dental models were reconstructed by using the three-dimensional (3D) dental model scanner.And then, Geomagic Studio, a 3D reverse engineering software, was employed to extract the single dental crown data, the mesiodistal and buccolingual diameters and the height of the crowns were measured.The object was reduced or enlarged by a numerical factor, and then the size of each dental crown was standardized.A total of 3-5 points features on the crown were created, and all the objects were aligned through the functions of feature-based alignment.Finally, through average-based object creation and smoothing, the digital models of reference crowns of the primary teeth were established.@*RESULTS@#A total of 40 plaster dental models from 16 boys and 26 girls were selected out for our further study.The digital dental models were reconstructed, and the mesiodistal and buccolingual diameters and the height of the crowns were measured by using reverse engineering technology.Comparing the results of using mesiodistal diameter, buccolingual diameter and height as the standards, we chose the mesiodistal diameters of crowns to do the standardization, and successfully established the digital reference models of 20 primary teeth crowns with detailed surface characteristics.@*CONCLUSION@#In this study, the digital reference crown models of the primary teeth were established by reverse engineering technology, providing reference value for the standardized crown models and application for clinical practice, scientific research and teaching.Furthermore, this study also contributes to the extensive application of CAD/CAM technology in pediatric dentistry and the development of CAD/CAM dental systems with independent intellectual property rights.

Esthetic evaluation of conventional and socket shield technique immediate implant restoration / 中华口腔医学杂志

Objective: To evaluate the pink and white esthetics of conventional and socket shield technique (SST) immediate implant restoration. Methods: Thirty volunteers were recruited according to preset criteria, and were assigned to 3 groups. Natural teeth group (ten undergraduates or postgraduates from Peking University School and Hospital of Stomatology in January 2020, n=10): all volunteers' maxillary anterior teeth were natural teeth with healthy gingiva, and none of the teeth were restored by crowns or composite. Conventional group and SST group (patients had a maxillary central incisor immediate implant placed in Department of Prosthodontics, Peking University School and Hospital of Stomatology during October 2016 to January 2021, n=10 for each group): the volunteer had an unrestored natural maxillary central incisor, and the contralateral maxillary central incisor was restored by conventional or SST immediate implant placement, temporization and all ceramic final restoration, photos were taken 12 months post-surgery. Three groups of evaluators namely layperson (staff from Second Clinical Division of Peking University School and Hospital of Stomatology and 2 family members, n=10), dental students (class 2015 undergraduates from Peking University School and Hospital of Stomatology, n=10) and prosthodontists (from Department of Prosthodontics, Peking University School and Hospital of Stomatology, n=10) were invited to assess the esthetics using pink esthetic score (PES) and white esthetic score (WES). The results were statistically analyzed. Results: PES and WES of natural teeth group [9(8, 10) and 8(7, 10)] were significantly higher than conventional group [7(6,8) and 7(6,9)] (H=287.08, 132.79,P<0.01) and SST group [7(6, 9) and 8(7, 9)] (H=216.01, 101.21, P<0.01). SST group yielded higher PES than the conventional group (H=-71.06, P<0.01), yet had similar WES (H=-31.57, P>0.05). Dental students had significant lower PES and WES than prosthodontists (H=-120.90, -218.86, P<0.01) and layperson (H=-109.55, 134.97, P<0.01). Prosthodontists and layperson got similar PES (H=-11.36, P>0.05), however yielded different WES (H=-83.89, P<0.01). Conclusions: SST immediate implant placement obtained better pink esthetics than conventional protocol 12-month after implant surgery, profession may have significant impact on evaluators during pink and white esthetic evaluation.

Clinical outcome of single posterior implant-supported monolithic zirconia crowns fabricated using full digital workflow and conventional workflow: a 3-year follow-up / 中华口腔医学杂志

Objective: To compare the clinical performance of posterior single implant-supported monolithic zirconia crowns fabricated by full digital workflow and that of those fabricated by conventional workflow. Methods: This is prospective clinical research. Thirty-five patients who participated in a previous study during August 2017 to October 2018 at Department of Prosthodontics, Peking University School and Hospital of Stomatology were included in this 3-year follow-up study. The 35 patients, 17 females and 18 males, aged (49.0±15.4) years (24-86 years old), was allocated into two groups. In the full digital workflow group, intraoral scanning was taken immediately after implant placement, and a full zirconia implant crown was fabricated using model-free computer aided design/computer aided manufacturing (CAD/CAM) procedure (n=14). In the conventional group, a conventional impression was taken 3 months after implant placement and the stone model was produced. A full zirconia implant crown was fabricated using conventional model-based procedure (n=21). Three years following crown delivery, all the prostheses were evaluated in the aspect of color, surface roughness, contour and marginal integrity using modified US Public Health Service criteria (MUSPHS criteria). The soft and hard tissue around implant was evaluated using modified plaque index, probing depth (PD), number of implants with bleeding on probing, marginal bone loss (MBL). The biological and mechanical complication were also recorded. Statistical analysis was performed using independent samples t test, Mann-Whitney U test and Fisher's exact test. Results: The total survival rate of prosthesis and implant was 100% (35/35). No significant difference in MUSPHS criteria ratings on color, surface roughness, contour and marginal integrity of these crowns were found between the full digital workflow group and the conventional group (P>0.05). Sixteen out of the 35 crowns had a contour score of B due to loss of interproximal contact. Ten out of the 35 crowns had the screw hole sealing resin sinking or falling off, four in the full digital workflow group and six in the conventional group. There was no significant difference in the rate of prostheses mechanical complications between the two groups (P=1.000). For all the implants, there was no significant difference in MBL, PD, the modified plaque index, and number of implants with bleeding on probing between the two groups (U=119.50,133.00,142.50, t=-0.53, P>0.05). Conclusions: The clinical performance of implant-supported posterior single monolithic zirconia crowns fabricated by full digital workflow was stable. There was no significant difference in the clinical performance of the single implant crowns between the full digital workflow group and the conventional group.

Design of non-metallic crown for primary molars and analyzation of stress distribution: a finite element study / 中华口腔医学杂志

Objectives: To study the design of nonmetallic crowns for deciduous molars by means of computer aided design and to analyze the key parameters of the nonmetallic crowns of deciduous molars using finite element method. Methods: The three-dimensional model of a mandibular second primary molar was constructed by using a micro-CT system. The thickness of the crown was limited to 0.5 mm and four different crown shapes (chamfer+anatomic, chamfer+non-anatomic, knife edge+anatomic and knife edge+non-anatomic) were designed. Then, the crown shape was limited as chamfer+non-anatomic and five different thicknesses of the crown (0.50, 0.75, 1.00, 1.25, 1.50 mm) were designed, and three different materials, including polyetherketoneketone (PEKK), polymethylmethacrylate (PMMA) resin and resin-infiltrated ceramic, were applied to make the crown. Stress distribution and fatigue of each component of the model under vertical and oblique loadings were analyzed by using finite element method. Non-axial retention analysis was performed on chamfer+non-anatomic crowns, made of PMMA resin, with thicknesses of 0.50, 0.75, 1.00, 1.25 and 1.50 mm. Results: Among the four crown shape designs, the chamfer+non-anatomic type crown showed the lowest von Mises stress and the highest safety factor. By comparing three different materials, the resin-infiltrated ceramic group showed obvious stress concentration on the buccal edge of the crown and the PEKK group showed stress concentration in the adhesive layer. Results of non-axial retention analysis showed that the torques required by the crowns with five thicknesses at the same rotation angle were as follows: 4 856.1, 4 038.1, 3 497.3, 3 256.3 and 3 074.3 N⋅m, respectively. The comparison of areas of the adhesives fracture among groups were as follows: 0.5 mm group < 0.75 mm group < 1.00 mm group < 1.25 mm group < 1.50 mm group. Conclusions: In the design of nonmetallic crowns for primary molars, the edge of the crown should be designed as chamfer, the shape of the inner crown should be non-anatomical and the minimum preparation amount of the occlusal surface should be 1.00 mm. Among the three materials, PMMA resin, of which elastic modulus is similar to the dentin and the dental adhesive, might be the most suitable material for the crowns of primary molars.

Percepção e conhecimento de odontopediatras sobre o uso de coroas pré-fabricadas de aço e zircônia na reabilitação de dentes decíduos / Perception and knowledge of pediatric dentists about the use of prefabricated steel and zirconia crowns in the rehabilitation of deciduous teeth

Objetivo: O presente trabalho tem como objetivo avaliar o conhecimento dos odontopediatras e suas percepções, conhecendo as dificuldades que estes encontram frente ao desafio da reabilitação de dentes decíduos. Métodos: A pesquisa foi realizada por meio da aplicação de questionários on-line e a análise estatística foi descritiva e comparativa, com tabelas de frequência para as variáveis quantitativas. O teste não paramétrico de Qui-quadrado foi utilizado para estimar a associação entre as diferentes categorias dos dados e em todo o estudo, estipulou-se o nível de significância em 5%. Resultados: Os resultados da pesquisa mostraram que a maioria dos entrevistados conhecem as coroas pré-fabricadas de aço, porém sua aplicação em atendimentos de crianças com extensas destruições coronárias limita-se a 34,1% destes profissionais, sendo que a baixa utilização se deve à dificuldade de aquisição do material e falta de habilidade técnica. Já com relação às coroas pré-fabricadas de zircônia, 82,4% das odontopediatras as conhecem, mas a grande maioria não as utiliza devido à dificuldade de aquisição, falta de habilidade técnica e o seu alto custo. Não foi encontrada associação entre a dificuldade de planejamento dos casos e a consideração estética e o âmbito de trabalho do entrevistado, bem como o fato de conhecer as coroas pré-fabricadas e utilizá-las. Conclusão: Conclui-se que os materiais reabilitadores, como coroas pré-fabricadas de aço e de zircônia, são de certa forma bem conhecidos pelos odontopediatras, mas sua utilização em reabilitação de dentes decíduos ainda é limitada.

Aim: The present study aims to evaluate the knowledge of pediatric dentists and their perceptions, knowing the difficulties they face in the challenge to rehabilitate deciduous teeth. Methods: This study was carried out through the application of online questionnaires. The statistical analysis was descriptive and comparative, with frequency tables for the quantitative variables. The non-parametric chi-square test was used to estimate the association between the different categories of data, and the significance level was set at 5%. Results:The survey results showed that most respondents know about prefabricated steel crowns, but their application in the care of children with extensive coronary destruction is limited to 34.1% of these professionals. The low use is due to the difficulty of acquiring the material and the lack of technical skills. It was found that 82.4% of the pediatric dentists have knowledge about prefabricated zirconia crowns, but the vast majority do not use them due to the difficulty of acquisition, their lack of technical skills, and the product's high cost. No association was found between the difficulty of planning the cases and the esthetic consideration and sphere of work of the interviewee, nor regarding the fact of their having knowledge about the prefabricated crowns and using them. Conclusion: It can therefore be concluded that rehabilitation materials, such as prefabricated steel and zirconia crowns, are well-known by pediatric dentists, but their use in the rehabilitation of deciduous teeth is still limited.

Eficácia de enxerto de tecido conjuntivo em pacientes que receberam implantes em áreas estéticas: um estudo longitudinal prospectivo com acompanhamento de 4 anos / Single implant placement in the maxillary aesthetic área with us without connective tissue grafting: a prospective longitudinal study with a 4-year follow-up

Os implantes osseointegrados têm sido utilizados desde a década de 50, conforme a utilização dos implantes vem crescendo, suas complicações também aumentam, principalmente quando são instalados em áreas estéticas, onde há deficiência de tecido conjuntivo peri-implantar. O objetivo deste estudo longitudinal prospectivo com 4 anos de acompanhamento foi avaliar o aumento da espessura de tecido conjuntivo peri-implantar em implantes instalados em áreas estéticas com a utilização de enxerto de tecido conjuntivo. Uma amostra de 34 indivíduos foi utilizada de um estudo prévio, o grupo teste (n=16) recebeu enxerto de tecido conjuntivo (ETC) sobre os implantes e o grupo controle (n=18) apenas o implante dental, o estudo tem um "power" de 80% (p=0,05). Após a instalação das coroas, os pacientes foram acompanhados pelo período de 4 anos, baseline, 12 meses e 48 meses, e as seguintes análises foram realizadas: Espessura tecido periimplantar vestibular (EV), deiscência óssea (DO), altura do tecido queratinizado (AQ), avaliação estética (PES/WES e Índice de Jent), avaliação estética pelo paciente (VAS), melhora da qualidade de vida (OHIP) e medidas radiográficas (COm/d). Resultados: A análise entre os grupos não foi estatisticamente significativa para as variáveis AQ, COm/d, PES/WES, Índice de Jent, estética centrada no paciente e OHIP. A análise intragrupos da COm/d foi significante em todos os períodos, tanto no teste quanto no controle. Para AQ, houve diferença no grupo controle entre o baseline e os demais períodos; na EV do grupo teste houve uma diferença significante entre o baseline e 48 meses e entre os dados de 12 e 48 meses, observando-se uma diminuição da EV, OHIP houve diferença em ambos os grupos, entre início e fim de tratamento, já as comparações entre os grupos para as variáveis EV e COm/d foram estatisticamente significante , EV apresentou maiores valores no grupo teste e Com/d menores valores no controle .Conclusão: A colocação de ETC aumenta espessura de tecido mole e após 48 meses mantem a espessura de EV, melhora DO, não aumenta AQ, não melhora a estética do ponto de vista do paciente e do profissional e a qualidade de vida não difere daqueles que receberam apenas o implante (AU)

Osseointegrated implants have been used since the mid-1950s. As the use of implants has grown, their complications also increase, especially those installed in esthetic areas, when there is a deficiency of peri-implant connective tissue. The aim of this prospective longitudinal study with 4 years of follow-up was to evaluate the increase in peri-implant connective tissue thickness in implants placed in esthetic areas using a connective tissue graft. Thrity-four patients froma previous study were divided in two groups:Test group (n=16), which received connective tissue graft (CTG) over the implants and Control group (n=18), which only the dental implant was installed. the study has a power of 80% (p=0.05). After dental crown placement, the patients were followed for a period of 4 years ( baseline, 12 months and 48 months) and the following analyzes were performed: Peri-implant tissue thickness buccal (EV), bone dehiscence (BD), height of keratinized tissue (KT), aesthetic evaluation (PES/WES and Jent Indexand by patient (VAS), quality of life (OHIP) and radiographic measurements (COm/d) Results: The analysis between groups was not significant for the variables KT, COm/d, PES/WES, Jent Index, patient-centered aesthetics and OHIP. The intragroup analysis of COm/d was significant in all periods in both test and control groups. For KT, there was a difference in the control group between the baseline and the other periods; in the EV of the test group there was a significant difference between the baseline and 48 months and between 12 and 48 months, showing a decrease in EV. In relation to OHIP, there was a difference in both groups, between baseline and 48mo.Comparisons between groups for the variables EV and COm/d were statistically significant, EV presented higher values in the test group and COm/d lower values in the control. Conclusion: CTG increased soft tissue thickness and after 48 months maintained the EV thickness, improved DO, did not increase KT, did not improve esthetics from patient's point of view neither the professional, and the quality of life did not differ from those who received only the implant (AU)

Erbium laser in the debonding of ceramics: a literature review / Laser de érbio na remoção de cerâmicas: uma revisão de literatura

Background: The debonding of crowns and ceramic veneers with laser is already a reality in the clinic. It presents benefits in comparison to traditional removal with the use of a rotating instrument; however, there is still no consolidated protocol and many professionals use it without the necessary scientific basis. Objective: The aim of this work was to perform a literature review on the debonding of indirect ceramic restorations using the Er:YAG and Er,Cr:YSGG lasers to provide clinical professionals and the scientific community a careful analysis, and also to guiding the use of irradiation at laser for such procedures. Methods: Bibliographic searches were performed in the following databases: Pubmed, Web of Science and Google Scholar. According to the inclusion criteria adopted, twenty-seven clinical and in vitro studies were selected in the period from 2007 to 2021. In the present work, the composition of the crowns and facets, as well as the types of cement and the laser irradiation protocols adopted in the selected studies is detailed. Conclusions: It was concluded that the use of erbium lasers for debonding of indirect ceramic restorations proved to be more selective and conservative when compared to removal with a rotary diamond instrument. Furthermore, it was shown to be in more efficient in debonding different types of ceramics. However, there are great variations in the "debonding" protocols, which emphasizes the need for further studies that seek to standardize the irradiation protocols considering the different clinical situations (AU)

Antecedentes: A remoção de coroas e facetas cerâmicas com laser já é uma realidade clínica e apresenta benefícios em relação à remoção tradicional com uso de instrumento rotatório diamantado; entretanto, ainda não existe um protocolo consolidado e muitos profissionais o utilizam sem o embasamento científico necessário. Objetivos: O objetivo deste trabalho foi realizar uma revisão da literatura sobre a remoção de restaurações cerâmicas indiretas utilizando os lasers Er:YAG e Er,Cr:YSGG para fornecer uma análise cuidadosa aos profissionais clínicos e à comunidade científica, além de orientar o uso da irradiação a laser para tal aplicação. Métodos: As buscas bibliográficas foram realizadas, nas seguintes bases de dados: Pubmed, Web of Science e Google Scholar. De acordo com os critérios de inclusão adotados, foram selecionados vinte e sete estudos clínicos e in vitro no período de 2007 a 2021. No presente trabalho, a composição das coroas e facetas, bem como os tipos de cimento e os protocolos de irradiação laser adotados nos estudos selecionados foram detalhados. Conclusão: Concluiu-se que o uso dos lasers de érbio para remoção de restaurações cerâmicas indiretas mostrou-se mais seletivo e conservador quando comparado à remoção com instrumento rotatório diamantado, além de ser eficiente na remoção de diferentes tipos de cerâmicas. No entanto, existem grandes variações nos protocolos de "debonding", o que enfatiza a necessidade de novos estudos que busquem uma padronização dos protocolos de irradiação considerando as diferentes situações clínicas.(AU)

Análise de sobrevivência de coroas unitárias sobre pilares para CAD/CAM com diferentes alturas de cimentação / Comparative analysis between two different abutment heights in single crowns

Objetivo: Avaliar o comportamento biomecânico do pilar protético Link Universal (TiBase) com diferentes alturas em restaurações implanto-suportadas. Materiais e Métodos: foram utilizados 40 implantes cone morse Titaniumfix Profile (4 x 10 mm) em titânio, divididos em dois grupos (n=20): Link Universal curto (Short) e Link Universal longo (Long). Vinte implantes receberam o pilar protético Link Universal de 4,5 x 4 mm (Short) e vinte implantes receberam o pilar protético Link Universal de 4,5 x 5,5 mm (Long). Por meio da tecnologia CAD/CAM foram usinadas as coroas em zircônia, cimentadas sobre os pilares protéticos. No ensaio de carga máxima para fratura, o grupo Longo apresentou média de 41,1 ± 6,96 kgf, enquanto a média do grupo curto foi de 49,5 ± 7,68, sem diferença estatística entre eles. Os espécimes passaram pelo teste de sobrevivência em fadiga (2.000.000 ciclos na frequência de 2 Hz com aplicador de aço inoxidável de 1,6 mm de diâmetro), conforme parâmetros descritos na ISO 14801:2007 e não apresentaram falhas. Na sequência, foram submetidos ao teste de sobrevivência stepwise, os espécimes não apresentaram diferenças em relação ao número de ciclos para falha, porém, em relação à carga aplicada, o pilar Link Universal Longo mostrou-se mais resistente que o pilar Link Universal Curto. A análise por elementos finitos foi realizada com os parâmetros obtidos no teste stepwise, com aplicação de carga de 450 N em 30º, simulando a condição do teste de fadiga. Os desenhos foram montados com o software Rhinoceros (version 5.4.2 SR8, McNeel Noth America, Seattle, WA, EUA) e processados no software Ansys (version 19.2, ANSYS Inc., Houston, TX, USA). O comportamento biomecânico do conjunto composto por implante, pilar protético, parafuso passante e coroa monolítica foi semelhante entre os grupos. Concluiu-se que ambas alturas da área de cimentação do pilar Link Universal apresentaram comportamento à fadiga favorável à sobrevivência clínica. (AU)

Objective: Evaluate the biomechanical behavior of the Universal Link (Ti-Base) prosthetic abutment with different heights in implant-supported restorations. Materials and Methods: 40 Titaniumfix Profile implants (4 x 10 mm) in titanium were used, divided into two groups (n=20): Short Universal Link (Short) and Long Universal Link (Long). Twenty implants received the 4.5 x 4 mm Link Universal Prosthetic Abutment (Short) and twenty implants received the 4.5 x 5.5 mm Link Universal Prosthetic Abutment (Long). Using CAD/CAM technology, the zirconia crowns were machined and cemented on the prosthetic abutments. In the maximum fracture load test, the Long group presented an average of 41.1 ± 6.96 kgf, while the average of the short group was 49.5 ± 7.68, with no statistical difference between them. The specimens passed the fatigue survival test (2,000,000 cycles at a frequency of 2 Hz with a stainless steel applicator with a diameter of 1.6 mm), according to the parameters described in ISO 14801:2007 and showed no failures. Subsequently, they were submitted to the stepwise survival test, the specimens did not show differences in relation to the number of cycles to failure, however, in relation to the applied load, the Long Universal Link abutment was more resistant than the Short Universal Link abutment. The finite element analysis was performed with the parameters obtained in the stepwise test, with a load of 450 N at 30º, simulating the condition of the fatigue test. The drawings were assembled with Rhinoceros software (version 5.4.2 SR8, McNeel Noth America, Seattle, WA, USA) and processed in Ansys software (version 19.2, ANSYS Inc., Houston, TX, USA). The biomechanical behavior of the set consisting of implant, prosthetic abutment, through screw and monolithic crown was similar between the groups. It was concluded that the Link Universal abutment presented fatigue behavior favorable to clinical survival independently of it's height (AU)

In Vitro Microscopic Evaluation of Metal- And Zirconium-Oxide-Based Crowns' Marginal Fit

ABSTRACT Objective To evaluate the marginal adaptation of computer-aided designing and computer-aided machining (CAD/CAM) fabricated cobalt-chromium and zirconium-oxide-based ceramic crowns compared to those produced by a conventional method. Material and Methods The study consists of three groups; 45 crowns fabricated from cobalt-chromium (CAD-CoCr) and 45 crowns manufactured from zirconium CAD/CAM technology (CAD-Z), and 45 control (C) which consists of conventional metal-ceramic crowns. The marginal discrepancies in vertical dimensions were assessed utilizing a microscope in four surfaces (mesial, distal, vestibular, and oral) for each crown. On completion of the microscopic evaluation, multivariate analysis of variance (MANOVA) was used to study the difference in the four surfaces, considered altogether. Two-way ANOVA revealed the effect of three systems used for gap measurements of each landmark. The differences observed were considered significant at p<0.05. Results There were no differences in the four surfaces revealed by АNOVА in the three groups when considered altogether. Two-way ANOVA of each surface discovered no differences among all groups as well. Conclusion The CAD/CAM crowns revealed a comparable and satisfactory marginal adaptation compared to conventional metal-ceramic crowns.

Enfoque de Tratamiento de una Adolescente con Amelogénesis Imperfecta / Treatment Approach for an Adolescent with Amelogenesis Imperfecta

La amelogénesis imperfecta (AI) es un grupo de tras-tornos hereditarios, clínica y etiológicamente hete-rogéneos, derivados de mutaciones genéticas, que se caracterizan por anomalías cualitativas y cuanti-tativas del desarrollo del esmalte, pudiendo afectar la dentición primaria y/o permanente. El tratamiento del paciente con AI es complejo y multidiscliplinario; supone un desafío para el odontólogo, ya que por lo general están involucradas todas las piezas dentarias y afecta no solo la salud buco dental sino el aspecto emocional y psicológico de los pacientes. Con el obje-tivo de describir el tratamiento integral y rehabilita-dor realizado en una paciente con diagnóstico de AI tipo III, se reporta el caso de un adolescente de sexo femenino de 13 años, que concurrió en demanda de atención a la Cátedra de Odontología Integral Niños de la Facultad de Odontología de la Universidad de Buenos Aires (FOUBA), cuyo motivo de consulta fue la apariencia estética y la hipersensibilidad de sus pie-zas dentarias. Durante el examen clínico intraoral, se observó que todas las piezas dentarias presentaban un esmalte rugoso, blando, con irregularidades y una coloración amarronada, compatible con diagnóstico de Amelogénesis Imperfecta tipo III hipomineralizada. Conclusión: El tratamiento rehabilitador de la AI en los pacientes en crecimiento y desarrollo estará diri-gido a intervenir de manera integral y temprana para resolver la apariencia estética y funcional, evitar las repercusiones sociales y emocionales, y acompañar a los pacientes y sus familias (AU)

Amelogenesis imperfecta (AI) is a group of clinically and etiologically heterogeneous hereditary disorders, derived from genetic mutations, characterized by qualitative and quantitative anomalies of enamel development, which can affect primary and/or permanent dentition. The treatment of patients with AI is complex and multidisciplinary, it is a challenge for the dentist, since in general all the teeth are involved and it affects not only oral health but also the emotional and psychological aspect of the patients. Objective: To describe the comprehensive and rehabilitative treatment carried out in an adolescent patient with a diagnosis of type III AI. Case report: The case of a 13-year-old female patient, who required dental attention at the Department of Dentistry for Children of the School of Dentistry of the University of Buenos Aires, whose reason for consultation was esthetic appearance and hypersensitivity of her teeth. In the intraoral clinical examination, it was observed that all the teeth had rough, soft enamel, with irregularities and a brownish color, compatible with the diagnosis of type III hypomineralized Amelogenesis Imperfecta. Conclusion: Rehabilitative treatment of AI in growing and developing patients will be aimed at early and comprehensive intervention to resolve esthetic and functional appearance, avoid social and emotional repercussions and accompany patients and their families (AU)

Esthetic rehabilitation with indirect resin on anterior teeth: a clinical report / Reabilitação estética com resina indireta em dentes anteriores: um relato clínico / Rehabilitaciónestética con resina indirecta en dientes anteriores: reporte clínico

Introduction:The aesthetic rehabilitation of endodontically treated teeth depends on the destruction degree of the crown, the bone support, type of prosthesis, andchewing forces. In these cases, indirect restorations with composite resins are an excellent alternative. The indirect composite resins have improved physical and mechanical properties due toincorporatingof inorganic fillersand multifunctional monomers. These components offer a greater bonding strength to the indirect restorations, which is advantageous for further rehabilitations with ceramic crowns. Objective:To present an aesthetic rehabilitation of anterior teeth with indirect composite resin as a feasible and less expensive treatment alternative.Case Report:Upon clinical examination, extensive and deficient restorations were observed in the upper anterior teeth. The proposed treatment plan was the aesthetic rehabilitation of endodontically treated teeth with indirect restorations using ceromer.Conclusions:This treatment represented an excellent alternative for aesthetic rehabilitation of endodontically treated teeth in cases of great dental crown destruction or small dental absences (AU).

Introdução:A reabilitação estética de dentes tratados endodonticamente depende do grau de destruição da coroa, do dente em questão, do suporte ósseo, do tipo de prótese e dos tipos de forças a que esses dentes serão submetidos. As resinas compostas indiretas apresentam propriedades físicas e mecânicas aprimoradas graças à incorporação de componentes inorgânicos e monômeros multifuncionais com maior número de pontos de união, tornando-os capazes de solucionar os problemas em que seriam indicadas restaurações cerâmicas. Objetivo:Apresentar um relato de caso clínico de uma reabilitação estética de dentes anteriores com resina composta indireta como alternativa de tratamento viável e de menor custo.Relato de Caso:Ao exame clínico foram observadas restaurações amplas e deficientes nos dentes anteriores superiores. O plano de tratamento proposto reabilitação estética dos elementos dentários com cerômeros.Conclusões:Este tratamento representou uma opção viável e demenor custo que pode ser utilizado tanto em situações de grande destruição dentária como em pequenas ausências dentárias, em substituição às restaurações de cerâmica (AU).

Introducción: La rehabilitación estética de los dientes tratados endodónticamente depende del grado de destrucción de la corona, el diente en cuestión, el soporte óseo, el tipo de prótesis y los tipos de fuerzas a las que estos dientes serán sometidos. Las resinas compuestas indirectas tienen propiedades físicas y mecánicas mejoradas gracias a la incorporación de componentes inorgánicos y monómeros multifuncionales con mayor número de puntos de unión, lo que las hace capaces de resolver los problemas en los que estarían indicadas las restauraciones cerámicas. Objetivo: Presentar un caso clínico de rehabilitación estética de dientes anteriores con resina compuesta indirecta como alternativa de tratamiento viable y menos costosa. Reporte de Caso:En el examen clínico, se observaron restauraciones extensas y deficientes en los dientes anteriores superiores. El plan de tratamiento propuesto para la rehabilitación estética de elementos dentales con cerómeros. Conclusiones:Este tratamiento representó una opción viable y menos costosa que se puede utilizar tanto en situaciones de gran destrucción dentaria como en pequeñas ausencias dentales, en sustitución de las restauraciones cerámicas (AU).

Spectrophotometric evaluation of coronal discoloration induced by bioceramic root canal filling materials / Evaluación espectrofotométrica de la decoloración coronal inducida por materiales biocerámicos de obturación del conducto radicular

The aim of this study is to evaluate the crown discoloration induced by bioceramic root canal filling materials (OrthoMTA and iRoot SP) compared to AH Plus. Material and Methods: Sixty intact mandibular single rooted premolars were sectioned 2 mm below the cemento-enamel junction, prepared, and randomly assigned into four groups according to the root filling materials: OrthoMTA, iRoot SP, AH Plus and unfilled. Results: Before placement of the materials in the pulp chamber and the coronal third of the root, the spectral reflectance lines of the crowns were recorded by a digital spectrophotometer at baseline, and after filling at 1 week and 1, 3 and 6 months and ∆Ε values were calculated. All materials used induced clinically perceptible crown discoloration (∆Ε>3.7) and no significant difference was detected between these materials (p>0.05). Regardless of the material, discoloration progressed significantly within the three months (p<0.05) however, at 6 months, the discoloration reduced for AH Plus and no further increase for bioceramic materials was detected. Conclusion: Bioceramic root filling materials tested induced clinically perceptible crown discoloration and their application in the esthetic zone should be performed with caution.

Objetivo: El objetivo de este estudio es evaluar la decoloración de la corona inducida por materiales biocerámicos de obturación del conducto radicular (OrthoMTA e iRoot SP) en comparación con AH Plus. Material y Métodos: Se seccionaron sesenta premolares mandibulares de raíz única intactos, 2 mm por debajo de la unión cemento-esmalte, se prepararon y se asignaron al azar en cuatro grupos de acuerdo con los materiales de obturación radicular: OrthoMTA, iRoot SP, AH Plus y sin relleno. Resultados:Antes de la colocación de los materiales en la cámara pulpar y el tercio coronal de la raíz, las líneas de reflectancia espectral de las coronas se registraron con un espectrofotómetro digital al inicio del estudio, y a la semana 1, así como a 1, 3 y 6 meses, y los valores ?? fueron calculados. Todos los materiales utilizados indujeron una decoloración de la corona clínicamente perceptible (??> 3,7) y no se detectaron diferencias significativas entre estos materiales (p> 0,05). Independientemente del material, la decoloración progresó significativamente dentro de los tres meses (p<0.05); sin embargo, a los 6 meses, la decoloración se redujo para AH Plus y no se detectó ningún aumento adicional para los materiales biocerámicos. Conclusiones: Los materiales biocerámicos de obturación radicular probados indujeron una decoloración de la corona clínicamente perceptible y su aplicación en la zona estética debe realizarse con precaución.