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OBJECTIVE: The purpose of this in vitro study was to evaluate the effect of staining, glazing, and polishing on the survival probability of monolithic crowns manufactured with preshaded stabilized zirconia with 5 mol% of yttrium oxide (5Y-TZP). MATERIALS AND METHODS: Monolithic crowns in the shape of an upper canine (1.5 mm of thickness) were manufactured by CAD/CAM, adhesively cemented on metallic foundation, and divided into 6 groups (n = 21): C (control), S (staining), G (glazing), P (polishing), SG (staining and glazing), and SP (staining and polishing). The survival probability was determined by step-stress accelerated life testing with a load applied to the palatine concavity of the crown. First, the specimens were subjected to a single-load to fracture test (SLF) and next to the fatigue test (5 Hz, thermocycling immersed in water varying 5-55°C), including the light (n = 9), moderate (n = 6), and aggressive (n = 3) loading profiles (load ranged between 20% and 60% of SLF). The survival probability was calculated considering the cycles for failure (CFF) and fatigue failure load (FFL) and illustrated using a Kaplan-Meier graph. The comparison among groups was performed using a Log-Rank test (α = 0.05). RESULTS: The mean value of SLF was 586.7 N. There was no difference among groups in survival probability, considering CFF and FFL. CONCLUSION: Staining, glazing, and polishing can be performed safely without damaging the mechanical behavior of 5Y-TZP monolithic crowns. CLINICAL SIGNIFICANCE: Staining is used to characterize and improve the esthetic of zirconia monolithic crowns. It can be used to reproduce the color gradient in the cervical region of the crown and pigmented grooves. This study showed that staining, glazing, and polishing did not affect the survival probability and the use of finishing procedures (glazing or polishing) after staining did not improve the survival probability of zirconia monolithic crowns.

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C-tetra(4-methoxyphenyl)calix[4]resorcinarene was synthesized by hydrochloric acid-catalysed cyclocondensation of resorcinol and 4-methoxybenzaldehyde. Under these conditions, the reaction produces a conformational mixture of crown and chair structural conformers, which were separated and characterized by chromatographic and spectroscopic techniques. The antioxidant activity of both conformers was measured by using the DPPH assay, through which it was observed that the chair conformer showed greater antioxidant activity (IC50 = 47.46 ppm) than the crown conformer (IC50 = 78.46 ppm). Additionally, it was observed that the mixture of both conformers presented lower antioxidant activity than either conformer in isolation. The results found suggest that the chair conformer has efficient antioxidant activity that makes it a potential target for further research.

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O sorriso gengival possui inúmeras causas, podendo acontecer por motivos esqueléticos, musculares ou por alteração no desenvolvimento dos tecidos de suporte. No entanto, na atualidade, a estética vermelha e a branca têm se apresentado completamente passíveis de transformações e com uma gama de procedimentos cirúrgicos ou não cirúrgicos para sanar as queixas dos pacientes. O objetivo geral deste trabalho é mostrar o poder que a odontologia tem frente às questões estéticas, como, por exemplo, a vergonha de sorrir por não se sentir confortável com os dentes curtos e com uma grande faixa de gengiva sendo exposta. O método utilizado foi um relato de caso. Que descreve todos os passos clínicos do tratamento de um paciente de 40 anos, que estava insatisfeita com o seu sorriso por apresentar erupção passiva alterada juntamente com hiperatividade do lábio superior. O plano de tratamento escolhido foi de realizar a cirurgia de aumento de coroa clínica estético, seguido de clareamento dentário e posteriormente um reposicionamento labial, com ajuda da toxina botulínica. Finalizando, para ajudar na cicatrização, o uso de laserterapia. O resultado de todo o processo cirúrgico envolvido neste trabalho, é satisfação do paciente, materializando o sonho deste, devolvendo segurança e espontaneidade ao sorrir. Pôde-se observar que através da combinação de técnicas cirúrgicas periodontais para tratar o sorriso gengival, obtém-se êxito tanto no sentido científico quanto no biológico, alcançando um sorriso esteticamente mais atrativo(AU)

Gummy smile has numerous causes, which can occur for skeletal or muscular reasons or due to changes in the development of supporting tissues. However, nowadays, the red and white aesthetics have been completely capable of transformation and with a range of surgical or non-surgical procedures to resolve patients' complaints. The general objective of this work is to show the power that dentistry has in the face of aesthetic issues, such as, for example, the shame of smiling due to not feeling comfortable with short teeth and a large strip of gum being exposed. The method used was a case report. Which describes all the clinical steps of the treatment of a 40-year-old patient, who was dissatisfied with her smile due to an altered passive eruption together with hyperactivity of the upper lip. The chosen treatment plan was to perform aesthetic clinical crown augmentation surgery, followed by tooth whitening and later lip repositioning, with the help of botulinum toxin. Finally, to help with healing, the use of laser therapy. The result of the entire surgical process involved in this work is patient satisfaction, materializing the patient's dream, restoring security and spontaneity when smiling. It was observed that through the combination of periodontal surgical techniques to treat gummy smile, success is achieved both in the scientific and biological sense, achieving a more aesthetically attractive smile(AU)

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Post-harvest diseases like fruit crown rot (CR) on bananas (Musa spp.) worldwide are mainly attributed to Colletotrichum gloeosporioides (Berk. & Curt.) von Arx and Lasiodiplodia theobromae (Pat.) Griff. & Maubl (Sangeetha et al., 2012; Riera et al., 2019). In April 2019, at a banana farm (cultivar Williams) located in El Oro province (location at 79° 54' 05" W; 03° 17' 16" S), thirty hands were randomly collected from the postharvest process and further placed in a humid chamber at 20 ºC until signs of the disease progressed and became more evident (from 3 days to 20 days). Ten hands presented initial symptoms related to CR during the postharvest process, which included crown or peduncle rot with mycelial development on the crown's surface, leading to the blackening of tissues at the site of the wound left when the cluster was cut. Crown fruit fragments (~0.5 cm) from the edge of healthy tissue and diseased tissue underwent a series of disinfection steps, initially in ethanol (70%) for 1 min, followed by sodium hypochlorite (1%) for 1 min, rinsed three times with sterile distilled water, and dried on sterile filter paper for 10 min. The fragments were placed onto Potato dextrose agar (PDA) + chloramphenicol (100 mg L-1) and incubated at 25°C in darkness for five days. Five isolates with different colony morphologies were obtained. An initial screen of the pathogenicity of all isolates showed that only one isolate showed disease activity in banana crowns. This isolate, C1, showed grayish-white aerial mycelium in culture as described above and, after ten days, became black. We did a full pathogenicity test with C1 using ten individual banana fruits (cv. Williams Cavendish). Briefly, one disc (Ø of 5 mm) of the fungus with agar was placed on the acropetal part of the banana fruit (on the peel) and another piece in the crown without wounding. Inoculated fruit were in a humid chamber at 20 °C for 20 days. Uninoculated fruits constituted the control. Isolate C1 caused 100% of the fruit and crowns to rot, with symptoms similar to those initially observed from fruit collected at the postharvest process (Fig. S1d). The fungus was re-isolated from symptomatic tissue, and its identity was confirmed through morphological characteristics consistent with Lasiodiplodia sp. Matured conidia of all mono hyphal strains (Fig. S1b) appeared dark brown with a single septum, having an ovate shape, and displayed longitudinal striations along their thickened walls (Fig. S1c). The dimensions of the mature conidia ranged from 16.02 - 26.85 x 11.09 - 16.74 µm (n = 60). Morphological characteristics showed similarity to Lasiodiplodia sp. (Alves et al., 2008). Microscopic observations were further confirmed by sequencing three loci: the internal transcribed spacer (ITS), ß-tubulin, and partial translation elongation factor-1α (TEF-1α). Fungal genomic DNA from the C1 isolate was PCR amplified using ITS5/ITS4, EF1-728F/986R, and Bt2A/Bt2B primers, respectively, according to Glass & Donaldson (1995) and Bautista-Cruz et al. (2019). The resulting amplicons were sequenced, and those sequences were deposited in GenBank with the accession numbers ITS: PP532861, TEF-1α: PP551938, and ß-tubulin: PP537587. Sequence alignment was conducted using ClustalW under the MEGA 11.0 software package (Tamura et al., 2021). Subsequently, phylogenetic analysis was performed using Bayesian inference using the BEAST v1.8.4 program (Drummond & Rambaut, 2007). The concatenated sequence of the isolate revealed clustering to the Lasiodiplodia theobromae clade, confirming its identity. To our knowledge, this is the first report of this pathogen causing CR on banana fruit in Ecuador. Based on the report of CR in the country, banana exporters and the Ecuadorian government should consider developing disease management methods that include the cultivation, shipping, ripening, and storage processes of the fruit.

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El recontorneo estético es una cirugía plástica periodontal que tiene como objetivo restablecer una sonrisa más armoniosa de acuerdo al aspecto facial del paciente, el principal motivo para realizar este procedimiento es cuando existe un diagnóstico de una erupción pasiva alterada o sonrisa gingival. La sonrisa gingival es una de las principales preocupaciones de acuerdo a la estética cuando existe una exposición gingival de más de 3 mm en lo cual es justificable realizar el recontorneo estético. Paciente femenino de 28 años de edad, con diagnóstico de erupción pasiva alterada 1B con un seguimiento de 4 meses. El tratamiento consistió en realizar el recontorneo estético para corregir la sonrisa gingival. El recontorneo estético es un procedimiento quirúrgico que se realiza con el objetivo de mejorar la estética del paciente cuando existe una exposición gingival excesiva y para facilitar la armonía de acuerdo a su aspecto facial.

Esthetic recontouring is a periodontal plastic surgery that aims to restore a more harmonious smile according to the patient's facial appearance, since the main reason to perform this procedure is when there is a diagnosis of an altered passive eruption or gingival smile. The gingival smile is one of the main concerns according to aesthetics when there is a gingival exposure of more than 3 mm in which it is justifiable to perform the aesthetic recontouring. 28-year-old female patient with a diagnosis of altered passive eruption 1B with a 4-month follow-up. Treatment consisted of esthetic recontouring to correct the gingival smile. Esthetic recontouring is a surgical procedure performed with the aim of improving the patient's esthetics when there is excessive gingival exposure and to facilitate harmony according to facial appearance.

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The crown lengthening is indicated for aesthetic purposes, exposure of subgingival caries, crown fractures or a combination of these, which can be characterized as aesthetic or functional, related to restorative indications, and restoration of biological width. Several factors need to be evaluated in the aesthetic planning for optimizing the smile, with the inclusion of an increase in the clinical crown, emphasizing the quality of the thin or thick periodontal phenotype, an adequate band of keratinized tissue and the size of the biological width. A correct diagnosis of the gummy smile etiology, as well as an assessment of clinical characteristics and anatomical dimensions, is of fundamental importance prior to the patient's approach. It determines and guide decisions regarding the possibilities of treatment and prognosis of cases. The aim of this study was to report two cases of cosmetic periodontal surgery with techniques commonly used for this purpose: gingivectomy and flap surgery with osteotomy.

El alargamiento clínico de corona está indicado con fines estéticos, exposición de caries subgingivales, fracturas coronarias o alguna combinación de estas, y puede caracterizarse como estético o funcional, relacionado con indicaciones restaurativas y restauración del espacio biológico. Varios factores deben ser evaluados en la planificación estética para optimizar la sonrisa, con la inclusión del aumento clínico de coronas, destacando la calidad del fenotipo periodontal delgado o grueso, la gama adecuada de tejido queratinizado y la dimensión del espacio biológico. Un diagnóstico correcto de las causas asociadas a la sonrisa gingival, así como una valoración de las características clínicas y dimensiones anatómicas, son de fundamental importancia antes de abordar al paciente, para determinar y orientar decisiones respecto a las posibilidades de tratamiento y pronóstico de los casos. El objetivo de este estudio fue reportar dos casos de cirugía periodontal estética con técnicas comúnmente utilizadas para este fin: gingivectomía y cirugía de colgajo con osteotomía.

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BACKGROUND: The present study aimed to assess the frequency and variation of 13 nonmetric dental crown traits (NDCT) in permanent and primary molars in German orthodontic patients. METHODS: Dental records from orthodontic patients were screened and evaluated. First and second permanent and primary upper and lower molars (from left and right sides) were assessed. Teeth with cavitated dental caries, occlusal wear, restorations and obvious dental deformities were not evaluated. The NDCT for permanent molars were identified and scored according to the odontoscopic system developed by Arizona State University Dental Anthropology System (ASUDAS). The NDCT for primary molars were identified and scored according to ASUDAS, Hanihara's method and Sciulli's method. The χ2 test was used to investigate side preference and sexual dimorphism at a significance level of p ≤ 0.050. RESULTS: A total of 163 orthodontic patients (82 males and 81 females) aged 8-14 years were included. A sexual dimorphism was observed for the hypocone in first upper permanent molar (p = 0.041). The protostylid was observed in lower permanent molars (range 2.1-10%). Males presented more hypoconulid than females (p = 0.019). Only females presented the distal trigonid crest in lower first permanent molars (p = 0.002). The most common groove pattern in primary molars was Y; male presented more Y grade than females in the lower second primary molar (p = 0.039). Asymmetry was observed in some traits, ranging from 0 to 100%. CONCLUSION: The present study showed the frequency of NDCT of molars in German orthodontic patients and demonstrated that some traits present sexual dimorphism.

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Purpose: This prospective study evaluated the effects of the metal-free crowns on the periodontal tissues of abutment teeth during a 12-month follow-up. Materials and Methods: A sample of 24 patients (N = 32 abutment teeth) who needed a single-tooth restoration were enrolled to receive either a metal-ceramic (n = 21) or lithium disilicate (n = 11). The single-unit crowns were evaluated at baseline, 3-and 12-month follow-up. The periodontal parameters were evaluated: plaque index (PI), gingival bleeding index (GBI), bleeding on probing (BOP), probing depth (PD), clinical attachment loss (CAL), radiographically and clinical crown fitting, bone resorption, and marginal finish lines. Statistical analyses were performed using the Exact Fisher and Mann-Whitney tests, and the Wilcoxon signed-rank test as a post hoc test for Friedman (95 % confidence interval). Results: The marginal finish line showed a statistical difference with a biomaterial type (p =.004). After a 12-months, a significant increase was observed in PI and mean PD for abutment teeth of metal-ceramic crowns. The metal-free crowns presented higher values for GBI and CAL (p2 < 0.05). Only distal cervical evaluation and dental biofilm formation in the abutment teeth showed a statistical difference between the groups at the 12-month follow-up. The supragingival margin metal-ceramic group revealed higher PI values (p2 = 0.005) between the period and the subgingival margin of both biomaterials showed greater GBI scores (p2 < 0.05). Conclusions: Metal-free crowns showed better periodontal outcomes compared to metal-ceramic crowns. Single-unit crown marginal location affects the periodontal tissue condition of the abutment teeth. The marginal fit was not changed regarding the biomaterial type.

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OBJECTIVE: To compare the clinical periodontal parameters of teeth restored with a single ceramic crown, with and without crown lengthening procedure. METHODS: This prospective, longitudinal, controlled, and single-blinded clinical trial involved 22 patients with a total of forty-one teeth with ceramic crowns. The teeth were divided into two groups: test (n = 21), comprising teeth rehabilitated post crown-lengthening surgery, and control (n = 20), comprising teeth rehabilitated without crown-lengthening surgery. Plaque index (PI), gingival index (GI), probing depth (PD), bleeding on probing (BoP), and clinical attachment level (CAL) were compared between groups (surgically treated and non-surgically treated) and within each group for each type of site (treated -tt; adjacent - ad; and nonadjacent - nad). Additionally, gingival phenotype (GP), gingival recession (GR), and keratinized tissue width (KTW) were also assessed post- restoration. Statistical analyses used a significance level set at 5 %. RESULTS: PI, GI, and BoP were reduced, but no statistically significant differences were observed within each group or between groups for most follow-up periods. CAL of the TT sites was consistently higher in the test group, and PD was also higher in the test group (p < 0.05), except at T3. adPD, nadPD, adCAL, and nadCAL demonstrated no significant differences between groups and periods. A significant association was identified between GP and the occurrence of GR, with the thick-flat phenotype demonstrating less association with GR, regardless of whether crown lengthening was performed or not. CONCLUSION: Crown-lengthening surgery in rehabilitated teeth does not significantly affect PI and GI after 12 months. Although crown-lengthening surgery affected PD and CAL in TT sites, it did not affect adjacent and non-adjacent sites. CLINICAL RELEVANCE: These findings emphasize the importance of considering individual patient factors and the potential impact on periodontal tissues when planning crown-lengthening surgery. Clinicians must have a comprehensive understanding of the dynamics of the periodontal tissues involved in restorative treatments to optimize the procedure, increase success rates, and minimize potential complications.

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BACKGROUND/AIM: Crown fractures are common traumatic dental injuries and tooth fragment reattachment is a viable option for restoring a fractured tooth. The aim of this study was to assess the knowledge and experience of dentists in the Federal District regarding the tooth fragment reattachment technique for enamel and dentin fractures. MATERIALS AND METHODS: For the cross-sectional observational study, an electronic form was designed with objective and self-report questions for dentists. The data were analyzed using descriptive statistics, with their absolute and relative frequencies. For the analysis of categorical variables, the nonparametric chi-squared or Fisher exact association tests were used in the statistical software R (version 4.2.1). RESULTS: A total of 416 dentists participated in the study (58.9% female and 41.1% male). Of these, 70% declared they knew about fragment reattachment, but only 42.3% reported previous experience with this procedure. The most common storage medium used for the fractured fragment was milk (78.1%), and the bonding material used for reattachment was light-cured composite resin (86.3%). A majority (66.3%) reported that for a patient with enamel and dentin fracture, with the crown fragment in good condition, they would choose to do the reattachment. CONCLUSION: Dentists demonstrated that they had adequate knowledge about the tooth fragment technique, although many did not have previous experience with this procedure.

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Objective: to present a 12-month follow-up with photographic and tomographic analyses of the effect of polymethyl methacrylate-based bone cement graft (PMMA) in gingival exposure (GE) in patients with excessive gingival display (EGD). Methods: Twelve patients with EGD were included. The PMMA was surgically placed. A frontal and lateral photograph protocol was performed at baseline (T0), 3 (T3), 6 (T6), and 12 months (T12) post-operatively. Soft tissue cone-beam computed tomography (ST-CBCT) was performed at T0 and T12. Measures included GE, length of the lip vermilion (LLV), lip shape (LS), nose width (NW), filter width (FW), nasolabial angle (NAS) while smiling, and nasolabial angle at rest (NAR). The height, thickness, and volume of the cement graft were also measured in the ST-CBCT. The comparisons were performed by Kruskal-Wallis test at 5 % of significance (p < 0.05). Results: The height, thickness, and volume of the PMMA were respectively 12.84 ± 1.59 mm, 3.83 ± 0.53, and 1532.02 ± 532.52 mm3. PMMA significantly decreased GE from 8.33 ± 1.25 mm (T0) to 6.60 ± 0.93 mm (T12) (p < 0.01). NAR was 98.34 ± 9.28° at T0 and increased to 105.13 ± 7.33° at T12; however, the angle value was not statistically different (p = 0.08). LLV, LS, NW, FW, and NAS did not exhibit statistical differences between the baseline and follow-up periods. Conclusions: PMMA significantly decreased GE in a 12-month follow-up without influencing adjacent soft tissue anatomical structures.

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A busca por um sorriso considerado perfeito tem sido cada vez maior e isso tem se tornado um desafio para o Cirurgião-Dentista, visto que um sorriso harmônico não envolve somente dentes, mas também gengiva. A exposição excessiva da gengiva ao sorrir ou falar é considerada uma característica antiestética, pois gera uma desarmonia entre dentes, gengiva e lábios. Quando o paciente expõe 3 milímetros ou mais de gengiva ao sorrir, chamamos essa exposição de Sorriso Gengival. O presente trabalho tem como objetivo relatar o tratamento de um caso de sorriso gengival, onde foi realizada cirurgia periodontal ressectiva a fim de diminuir a exposição de tecido gengival ao sorrir. Descrição do caso: Paciente adulto 21 anos, sexo masculino, procurou atendimento no curso de graduação em Odontologia do Centro Universitário da Serra Gaúcha ­ FSG, com queixa de insatisfação estética devido ao tamanho de seus dentes e mostrar muito tecido Gengival ao sorrir. Após anamnese, exame clínico e radiográfico, o paciente foi diagnosticado com Sorriso gengival. O plano de tratamento proposto foi de cirurgia periodontal ressectiva. Conclusão: A partir do exposto, podemos concluir que o tratamento do sorriso gengival depende de sua etiologia. Um correto diagnóstico é de extrema importância, pois dependendo do fator etiológico do sorriso gengival, o plano de tratamento pode ser elaborado de acordo com a necessidade do paciente. No caso apresentado, o procedimento escolhido, cirurgia periodontal ressectiva, se mostrou efetivo no tratamento do sorriso gengival, devolvendo estética e satisfação ao paciente(AU)

The search for a smile that is considered perfect has been increasing and this has become a challenge for the Dental Surgeon, since a harmonious smile does not only involve teeth, but also gums. Excessive exposure of the gums when smiling or talking is considered an unsightly feature, as it creates disharmony between teeth, gums and lips. When the patient exposes 3 millimeters or more of gum when smiling, we call this exposure Gummy Smile. The present work aims to report the treatment of a case of gummy smile, where resective periodontal surgery was performed in order to reduce the exposure of gingival tissue when smiling. Case description: A 21-year-old adult patient, male, sought care at the undergraduate course in dentistry at the Centro Universitário da Serra Gaúcha ­ FSG, complaining of aesthetic dissatisfaction due to the size of his teeth and showing a lot of gingival tissue when smiling. After anamnesis, clinical and radiographic examination, the patient was diagnosed with gummy smile. The proposed treatment plan was resective periodontal surgery. Conclusion: From the above, we can conclude that the treatment of gummy smile depends on its etiology. A correct diagnosis is extremely important, because depending on the etiological factor of the gummy smile, the treatment plan can be elaborated according to the patient's needs. In the case presented, the chosen procedure, resective periodontal surgery, proved to be effective in the treatment of gummy smile, restoring aesthetics and patient satisfaction(AU)

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OBJECTIVES: To evaluate the stability of periodontal tissues 3 (T3), 6 (T6), and 12 (T12) months after esthetic crown lengthening (ACL) and the possible correlations between changes in those structures. MATERIALS AND METHODS: Twenty individuals were evaluated through clinical assessment, photography, and tomography. Measurements included gingival margin (GM), clinical crown length (CCL), interdental papilla height (PH) and width (PW), gingival thickness (GT), bone thickness (BT), probing depth (PD), distance between alveolar crest and GM, distance between alveolar crest and cementoenamel junction. Nonparametric and correlation statistics were performed (p < 0.05). RESULTS: CCL at T0 was 7.42 ± 0.70 mm and increased to 9.48 ± 0.49 mm immediately after ACL, but it decreased to 8.93 ± 0.65 mm at T12. PD decreased 0.60 mm from T0 to T6, and it increased 0.39 mm from T6 to T12. BT decreased 0.20 mm, while GT increased 0.29 mm from T0 to T12. Both PW and PH showed enlargement in T12. A positive moderate correlation was found between CCL/T0 and CCL/T12, GT/T0 and AC-GM/T12, BT/T0 and GT/T12. A few negative moderate correlations were PD/T0 and CCL/T12, PD/T0 and PH/T0, PD/T0 and BT/T12. CONCLUSIONS: ACL procedure was effective. Although some rebound occurred, that was not clinically important. PD tended to reestablish its original length, partially due to a migration of GM during the healing period. Besides, a thickening of supracrestal soft tissues was observed. CLINICAL RELEVANCE: The present study centers on the factors influencing the stability of periodontal tissues after esthetic crown lengthening, underscoring the procedure's influence on esthetics and biology and the need for careful treatment planning.

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OBJECTIVE: To assess and compare, through a systematic review of the literature, the biomechanical performance of endocrowns and traditional core-crowns (with and without intracanal post) for the rehabilitation of endodontically treated teeth with severe coronal structure damage. MATERIALS AND METHODS: A systematic search was performed in MEDLINE/PubMed, Scopus, and Web of Science databases. In-vitro studies comparing endocrowns with (post-)core-crown restorations were selected and screened by two independent reviewers. The included studies were submitted to the risk of bias analysis using the RoBDEMAT tool and the biomechanical outcomes were collected for qualitative analysis. The extracted data were presented based on comparative analyses among the included studies. RESULTS: Thirty-one studies were included: 9 studies evaluated restorations of molars, 14 for premolars, and 8 studies evaluated anterior restorations. For the majority of the studies, endocrowns showed either similar or greater survival rates under fatigue and monotonic load than (post-)core-crown restorations, irrespectively of the tooth. The endocrowns showed more favorable failure patterns than (post-)core-crowns, irrespectively of the tooth. Endocrowns produced lower stresses in the restorative material for molars and premolars and in the luting material for premolars than (post-)core-crown restorations. The included studies presented adequate information for most items of the RoBDEMAT risk of bias tool. CONCLUSION: Endocrowns showed similar or greater biomechanical performance than the traditional (post-)core-crown restorations in most of the evaluated studies. CLINICAL SIGNIFICANCE: This systematic review showed that endocrowns present either similar or greater biomechanical performance than core-crown restorations for anterior and posterior endodontically treated teeth with severe structural damage.

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This study evaluated the stress distribution on an implant-supported zirconia crown of a mandibular first molar subjected to oblique loading by occlusal contact with the natural maxillary first molar by using the 3D finite element method. Two virtual models were made to simulate the following situations: (1) occlusion between maxillary and mandibular natural first molars; (2) occlusion between zirconia implant-supported ceramic crown on a mandibular first molar and maxillary natural first molar. The models were designed virtually in a modeling program or CAD (Computer Aided Design) (Rhinoceros). An oblique load of 100 N was uniformly applied to the zirconia framework of the crown. The results were obtained by the Von Mises criterion of stress distribution. Replacement of the mandibular tooth by an implant caused a slight increase in stress on portions of the maxillary tooth roots. The crown of the maxillary model in occlusion with natural antagonist tooth showed 12% less stress when compared with the maxillary (model in occlusion with the) implant-supported crown. The mandibular crown of the implant show 35% more stress when compared with the mandibular antagonist crown on the natural tooth. The presence of the implant to replace the mandibular tooth increased the stresses on the maxillary tooth, especially in the region of the mesial and distal buccal roots.

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Tooth enamel thickness is widely studied in primates and is important in differentiating taxa and in interpreting diet and feeding behavior. The objective of this study was to measure enamel thickness and discuss whether the results can be associated with different feeding patterns. Thirty-four syncraniums of Alouatta guariba clamitans, Alouatta caraya, and Sapajus nigritus were subjected to cone beam computed tomographic (CBCT) scans, and the dental enamel was measured in different regions of the crown using the multiplanar reconstruction tool. The differences observed indicate that for many variables and teeth, A. guariba clamitans showed significantly higher values compared to the other 2 species, with the exception of the cuspid region. Although the A. guariba clamitans is a folivorous species, it showed thicker enamel for most of the variables. CBCT was efficient in performing the measurements, allowing analysis of the syncraniums.

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BACKGROUND/AIMS: The recommended treatment for uncomplicated crown fractures is bonding the fractured fragment or the fragment reattachment. A paucity was identified regarding the studies comparing the efficacy of micro-hybrid and nanohybrid composites in fragment reattachment. Hence, the present study aimed to evaluate and compare three materials for bonding of fragments rehydrated by humidification in teeth with uncomplicated crown fractures. MATERIAL AND METHODS: Eighty mandibular bovine incisors with similar dimensions and free of any structural deformities were fractured similar to the technique followed in previous studies. Fracture was simulated, fragments, and stumps were coded, stumps were stored in artificial saliva and the fragments were dehydrated at room temperature and pressure. They were randomly assigned to Group-1 (no rehydration), Group-2 (rehydrated and bonded by flowable nanohybrid composite-3M Filtek Supreme Syringe Flowable Composite Resin-A2, Sao Paulo, Brazil), Group-3 (rehydrated and bonded by flowable micro-hybrid composite- Ruby Flow, InciDental, England, United Kingdom), and Group-4 (rehydrated and bonded by light-cured Glass-Ionomer-Cement-Voco Ionoseal, Cuxhaven, Germany). The samples were subjected to a universal testing machine to evaluate the force required to fracture the bonded fragments. RESULTS: The highest median value of the force required to fracture was recorded for Group 2 (208.4 N) followed by Group 3 (195.2). The force required to fracture the bonded fragments was lowest in Group 4 (67.2 N) which was lower than the negative control (131.4 N). The differences between the observations in Groups 2 and 3 were not found to be statistically significant. CONCLUSION: The nano and micro-hybrid composites showed greater force required to fracture than fragments bonded by LC-GIC. Dehydrated fragments bonded using nanocomposites performed better than rehydrated fragments bonded by using LC-GIC.

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OBJECTIVES: The aim of this case series is to present the potential applications of the GingivalStat approach, that is, the use of temporary gingival stabilizers, to favor early gingival margin remodeling and prevent the occurrence of gingival rebound following esthetic clinical crown lengthening. CLINICAL CONSIDERATIONS: Four patients requiring clinical crown lengthening were treated for esthetical and functional reasons. The surgical approach included: (a) gingival margin recontouring; (b) full-thickness flap elevation; (c) osteotomy (to achieve an adequate dimension between the alveolar bone crest and the CEJ) and osteoplasty (to reduce the bone thickness and improve the buccal bone anatomic profile, where indicated); (d) temporary gingival stabilizer placement using a block-out resin or a composite (the GingivalStat approach); and (e) flap repositioning, adaptation, and suture. One- to five-year follow-ups, reported in the different case scenarios, show evidence of clinically stable gingival margins around the treated teeth. CONCLUSIONS: Within the limits of this case series, it can be concluded that the GingivalStat approach appears as a further maneuver to cope with clinical crown lengthening procedures at esthetic sites. GingivalStat seems to favor gingival margin contour remodeling during the early phase of healing as well as prevent the occurrence of gingival rebound. CLINICAL SIGNIFICANCE: GingivalStat approach may guide gingival margin remodeling and prevent gingival rebound after wound healing of sites submitted to esthetic clinical crown lengthening.

Assuntos

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It is reported the synthesis, characterization by elemental analysis, thermogravimetry; electronic absorption, infrared, excitation, and emission spectroscopies of the [Eu(12C4)(phen)2(X)n]X2 complexes, where 12C4 = 12-crown-4, phen = 1,10-phenanthroline, and X  = F-, Cl-, Br-, SCN-, ClO4-, and NO3-. It is verified that the polarizability of the anion X- exerts remarkable effects on the emission process. As a general trend, lower wavenumbers for the 7F0→5L6, 7F0→5D2 and 7F0→5D1 transitions are associated with the anions with higher volumes and, consequently, higher polarizability. The molecular modeling results performed with quantum methods (RHF and DFT) suggest some relationships between the calculated structures, electronic, and luminescence properties with the presence of the LMCT (ligand-to-metal charge transfer) states, which explains the differences in the emission spectra of these complexes due to the coordinated anion.

RESUMO

OBJECTIVE: To explore the feasibility of the usage of digital guides in combination with low- and high-power lasers for the treatment of excessive gingival display, also known as "gummy smile". CLINICAL CONSIDERATIONS: Excessive gingival display due to altered passive eruption can affect patient's perception of their own esthetics and consequently have an impact on self-confidence. Therefore, the management of this condition should offer a predictable and stable long-lasting solution. To attain these objectives, digital planning emerges as a tool in optimizing the outcomes of crown lengthening surgery for this condition by enhancing precision through the use of surgical guides. Additionally, the usage of high- and low-powered lasers can provide a safe approach because of their tissue selective removal properties. CONCLUSIONS: The technique described showed satisfactory clinical results in the short- and long-term follow-up, leading to an improvement in patients' self-esteem. This approach integrates digital and laser technologies to deliver a surgical treatment characterized by precision, efficiency, and safety. CLINICAL SIGNIFICANCE: Digital dentistry has contributed to innovative dental procedures, as personalizing surgical guides for patients, assisting and guiding incisions of the gingival margins, as well as the extension of the osteotomy, during the procedures for increasing the clinical crown. Furthermore, smile esthetics are directly related to an individual's improved emotional and social quality of life.

Assuntos