Stress distribution in peri-implant bone, implants, and prostheses: 3D-FEA of marginal bone loss and prosthetic design / Distribuição de estresse no osso peri-implantar, implantes e próteses: análise 3D-FEA de perda óssea marginal e design protético

Objective: In response to the demand for dental implants, extensive research has been conducted on methods for transferring load to the surrounding bone. This study aimed to evaluate the stresses on the peripheral bone, implants, and prostheses under scenarios involving of the following variables: prosthesis designs, vertical bone heights, load angles, and restorative materials. Material and Methods: Three implants were inserted in the premolar and molar regions (5-6-7) of the two mandibular models. Model 1 represented 0 mm marginal bone loss and Model 2 simulated 3 mm bone loss. CAD/CAM-supported materials, hybrid ceramic (HC), resin-nano ceramic (RNC), lithium disilicate (LiSi), zirconia (Zr), and two prosthesis designs (splinted and non-splinted) were used for the implant-supported crowns. Forces were applied vertically (90°) to the central fossa and buccal cusps and obliquely (30°) to the buccal cusps only. The stresses were evaluated using a three-dimensional Finite Element Analysis. Results: Oblique loading resulted in the highest stress values. Of the four materials, RNC showed the low stress in the restoration, particularly in the marginal area. The use of different restorative materials did not affect stress distribution in the surrounding bone. The splinted prostheses generated lower stress magnitude on the bone, and while more stress on the implants were observed. Conclusion: In terms of the stress distribution on the peri-implant bone and implants, the use of different restorative materials is not important. Oblique loading resulted in higher stress values, and the splinted prosthesis design resulted in lower stress (AU)

Objetivo: Em resposta à demanda por implantes dentários, extensa pesquisa foi realizada sobre métodos para transferir carga ao osso circundante. Este estudo buscou avaliar os estresses no osso periférico, implantes e próteses em cenários que envolvem as seguintes variáveis: designs de próteses, alturas ósseas verticais, ângulos de carga e materiais restauradores. Material e Métodos: Três implantes foram inseridos nas regiões dos pré-molares e molares (5-6-7) de dois modelos de mandíbula. O Modelo 1 representou perda óssea marginal de 0 mm e o Modelo 2 simulou perda óssea de 3 mm. Materiais suportados por CAD/CAM, cerâmica híbrida (HC), cerâmica nano-resina (RNC), dissilicato de lítio (LiSi), zircônia (Zr) e dois designs de próteses (sintetizadas e não-sintetizadas) foram utilizados para as coroas suportadas por implantes. Forças foram aplicadas verticalmente (90°) à fossa central e cúspides bucais e obliquamente (30°) apenas às cúspides bucais. Os estresses foram avaliados usando Análise de Elementos Finitos tridimensional. Resultados: Cargas oblíquas resultaram nos valores mais altos de estresse. Entre os quatro materiais, RNC mostrou baixo estresse na restauração, especialmente na área marginal. O uso de diferentes materiais restauradores não afetou a distribuição de estresse no osso circundante. Próteses sintetizadas geraram menor magnitude de estresse no osso, enquanto mais estresse nos implantes foi observado. Conclusão: Em termos de distribuição de estresse no osso peri-implantar e implantes, o uso de diferentes materiais restauradores não é crucial. Cargas oblíquas resultaram em valores mais altos de estresse, e o design de prótese sintetizada resultou em menor estresse. (AU)

Análise mecânica comparativa do destorque de parafusos de minipilar com um novo componente protético, juntamente com avaliação microbiológica do vedamento para implantes de plataforma Cone Morse / Comparative mechanical analysis of the untorsion of miniabutment screws with a new prosthetic component, together with microbiological evaluation of the seal for Cone Morse platform implants

A interface implante pilar (IAI) por se constituir de duas peças inevitavelmente apresentam micro lacuna (GAP), na qual pode ocorrer infiltração bacteriana, permitindo a penetração de microorganismos que colonizam na parte interna do implante levando ao acúmulo de biofilme e, podendo levar ao desenvolvimento da periimplantite. O desgaste da conexão interna do implante é algo que ocorre com frequência, muitas vezes pela fratura do parafuso e/ou, pela perda da rosca interna do implante. A ausência de informações prévias também pode gerar a necessidade da remoção do implante, devido a estas intercorrências, surge a possibilidade da criação de um novo componente para implantes para possibilitar a reabilitação protética, sem ter que passar por uma nova cirurgia de remoção e instalação do implante. O objetivo do trabalho foi mensurar o nível de afrouxamento do parafuso do pilar protético e do minipilar comparando com novo componente protéticos, na tentativa de simular o comportamento do conjunto implante/pilar/prótese. Foram utilizados vinte implantes de plataforma cone morse (CM) da DSP® com seus respectivos mini pilares, na qual foram distribuídos em 2 grupos(n=10): Grupo 1 - implante CM + mini pilar FlexCone® DSP + coroa simplificada pirâmide invertida carga aplicada 3 mm do centro da coroa. E Grupo 2 - implante CM + mini pilar novo + coroa simplificada pirâmide invertida carga aplicada 3 mm do centro da coroa. Foram realizados ciclagem mecânica com carga 133 N, durante 2x106 ciclos, com frequência 2 Hz e temperatura de 37ºC em ambos grupos. Um torquímetro digital foi usado para medir os valores de torque reverso do parafuso protético da coroa e também do pilar protético, antes e após o carregamento. Os resultados do modelo de regressão demonstraram diferenças estatisticamente significativas em função do envelhecimento comparando os grupos da coroa sobre o pilar protético (p = 0.020) e entre os grupos do pilar sobre o implante (p = 0.048), indicando que após o envelhecimento de 2.000.000 de ciclos ao longo do tempo está associado de maneira significativa a essas variáveis no contexto deste estudo. O segundo objetivo deste estudo foi avaliar in vitro a taxa de infiltração bacteriana através da IAI, entre o novo componente protético e a superfície interna do implante, juntamente foi analisado a permeabilidade do IAI para colonização bacteriana. Um total de oitenta implantes foram testados. As estruturas montadas para grupo 1 foi torqueado com 20 N/cm e do G2 foram torqueados com 45 N, ambos imersos em microtubos contendo 200 µl de saliva humana. Após 14 dias de incubação da amostra de bactéria nos implantes, foi realizada uma análise qPCR (reação da cadeia da polimerase em tempo real). O teste revelou que não houve diferenças estatisticamente significativas no crescimento bacteriana entre os grupos em qualquer um dos pontos temporais analisados. Conclui-se que o novo componente testado apresentou um destoque menor do que comparado ao mini pilar FlexCone DSP® e apresentou infiltração bacteriana no GAP da conexão implante-pilar semelhante comparado ao mini pilar original da empresa (AU)

The abutment implant interface (IAI), as it consists of two pieces, inevitably presents a micro gap (GAP), in which bacterial infiltration can occur, allowing the penetration of microorganisms that colonize in the internal part of the implant, leading to the accumulation of biofilm and, which can lead to development of peri-implantitis. Wear of the implant's internal connection is something that occurs frequently, often due to screw fracture and/or loss of the implant's internal thread. The lack of prior information can also generate the need to remove the implant, due to these complications, the possibility arises of creating a new component for implants to enable prosthetic rehabilitation, without having to undergo a new surgery to remove and install the implant. implant. The objective of the work was to measure the level of screw loosening of the prosthetic abutment and the mini-abutment compared with the new prosthetic component, in an attempt to simulate the behavior of the implant/ abutment/prosthesis set. Twenty DSP® morse cone (CM) platform implants were used with their respective mini pillars, which were distributed into 2 groups (n=10): Group 1 - CM implant + FlexCone® DSP mini pillar + simplified crown inverted pyramid load applied 3 mm from the center of the crown. And Group 2 - CM implant + new mini abutment + simplified crown inverted pyramid load applied 3 mm from the center of the crown. Mechanical cycling was carried out with a load of 133 N, for 2x106 cycles, with a frequency of 2 Hz and a temperature of 37ºC in both groups. A digital torque wrench was used to measure the reverse torque values of the prosthetic crown screw and also the prosthetic abutment, before and after loading. The results of the regression model demonstrated statistically significant differences as a function of aging comparing the crown-on-prosthetic abutment groups (p =0.020) and between the abutment-on-implant groups (p = 0.048), indicating that after aging 2,000 ,000 cycles over time is significantly associated with these variables in the context of this study. The second objective of this study was to evaluate in vitro the rate of bacterial infiltration through the IAI, between the new prosthetic component and the internal surface of the implant, together with the permeability of the IAI for bacterial colonization. A total of eighty implants were tested. The assembled structures for group 1 were torqued with 20 N/cm and G2 were torqued with 45 N, both immersed in microtubes containing 200 µl of human saliva. After 14 days of incubation of the bacteria sample in the implants, a qPCR (real-time polymerase chain reaction) analysis was performed. The test revealed that there were no statistically significant differences in bacterial growth between groups at any of the time points analyzed. It is concluded that the new component tested presented a lower impact compared to the FlexCone DSP® mini abutment and presented bacterial infiltration in the GAP of the implant-abutment connection similar to the company's original mini abutment.(AU)

Complexos polieletrólitos de quitosana e xantana carregados com ativos naturais e sintéticos: estudo físico/químico e microbiológico para aplicação de drug delivery / Polyelectrolyte complexes of chitosan and xanthan loaded with natural and synthetic actives: physicochemical and microbiological study for drug delivery application

A eficácia dos implantes osseointegrados é amplamente reconhecida na literatura científica. Contudo, infiltrações bacterianas na junção implante-pilar podem desencadear inflamação nos tecidos circundantes, contribuindo para a evolução de condições mais sérias, como a peri-implantite. O objetivo desse estudo foi produzir complexos polieletrólitos (PECs) de quitosana (Q) e xantana (X) em forma de membranas, carregá-las com ativos naturais e sintéticos antimicrobianos, caracterizálas estruturalmente e avaliá-las frente a degradação enzimática, cinética de liberação e ações antimicrobianas com finalidade de aplicação para drug delivery. Membranas de QX a 1% (m/v) foram produzidas em três proporções, totalizando doze grupos experimentais: QX (1:1); QX (1:2), QX (2:1), QX-P (com própolis) (1:1); QX-P (1:2); QX-P (2:1); QX-C (com canela) (1:1); QX-C (1:2); QX-C (2:1) e CLX (com clorexidina 0,2%) (1:1); CLX (1:2); CLX (2:1). Para os estudos de caracterização foram feitas análises da espessura em estado seco; análises morfológicas superficial e transversal em Microscopia Eletrônica de Varredura (MEV); análise estrutural de espectroscopia de infravermelho por transformada de Fourier (FTIR); análise de degradação por perda de massa sob ação da enzima lisozima; e análise da cinética de liberação dos ativos em saliva artificial. Para os testes microbiológicos, análises de verificação de halo de inibição e ação antibiofilme foram feitas contra cepas de Staphylococcus aureus (S. aureus) e Escherichia coli (E. coli). Os resultados demonstraram que a espessura das membranas variou conforme a proporção, sendo que o grupo QX (1:2) apresentou a maior média de 1,022 mm ± 0,2, seguida respectivamente do QX (1:1) com 0,641 mm ± 0,1 e QX (2:1) com 0,249 mm ± 0,1. Nas imagens de MEV é possível observar uma maior presença de fibras, rugosidade e porosidade nos grupos QX (1:2) e QX (1:1) respectivamente, e, no QX (2:1) uma superfície mais lisa, uniforme e fina. No FTIR foram confirmados os picos característicos dos materiais isoladamente, além de observar as ligações iônicas que ocorreram para formação dos PECs. Na análise de degradação, os grupos com ativos naturais adicionados tiveram melhores taxas de sobrevida do que os grupos QX. No teste de liberação, os grupos QX-P tiveram uma cinética mais lenta que os QX-C, cuja liberação acumulada de 100% foi feita em 24 h. Já nos testes do halo inibitório, somente os grupos CLX tiveram ação sobre as duas cepas, e os QX-P tiveram sobre S. aureus. Nas análises antibiofilme, os grupos CLX apresentaram as maiores taxas de redução metabólica nas duas cepas (± 79%); os grupos QX-P apresentaram taxas de redução similares em ambas as cepas, porém com percentual um pouco maior para E. coli (60- 80%) e os grupos QX-C tiveram grande discrepância entre as duas cepas: de 35 a 70% para S. aureus e 14 a 19% para E. coli. Pode-se concluir que, frente as análises feitas, o comportamento do material foi afetado diretamente pelos ativos adicionados a matriz polimérica. As proporções de Q ou X afetaram somente a espessura final. Quanto a aplicação proposta de drug delivery, os dispositivos apresentaram grande potencial, principalmente os grupos CLX e QX-P. (AU)

The effectiveness of osseointegrated implants is widely recognized in scientific literature. However, bacterial infiltrations at the implant-abutment interface may trigger inflammation in surrounding tissues, contributing to the development of more serious conditions, such as peri-implantitis. The aim of this study was to produce chitosan (Q) and xanthan (X) polyelectrolyte complexes (PECs) in the form of membranes, load and evaluate them for enzymatic degradation, release kinetics, and antimicrobial actions for drug delivery applications. QX membranes at 1% (w/v) were produced in three proportions, totaling twelve experimental groups: QX (1:1), QX (1:2), QX (2:1), QX-P (with propolis) (1:1), QX-P (1:2), QX-P (2:1), QX-C (with cinnamon) (1:1), QX-C (1:2), QX-C (2:1), and CLX (with 0.2% chlorhexidine) (1:1), CLX (1:2), CLX (2:1). Characterization studies included analyses of dry state thickness, surface and crosssectional morphology using Scanning Electron Microscopy (SEM), structural analysis by Fourier Transform Infrared (FTIR) spectroscopy, mass loss degradation analysis under lysozyme action, and active release kinetics analysis in artificial saliva. Microbiological tests included verification analyses of inhibition halos and antibiofilm action against strains of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Results showed that membrane thickness varied according to proportion, with group QX (1:2) presenting the highest average of 1.022 mm ± 0.2, followed by QX (1:1) with 0.641 mm ± 0.1, and QX (2:1) with 0.249 mm ± 0.1. SEM images showed greater presence of fibers, roughness, and porosity in groups QX (1:2) and QX (1:1) respectively, while QX (2:1) exhibited a smoother, more uniform, and thinner surface. FTIR confirmed characteristic peaks of the materials individually, besides showing ionic bonds formed for PECs. Degradation analysis revealed that groups with added natural actives had better survival rates than QX groups. In release tests, QX-P groups exhibited slower kinetics than QX-C, with 100% cumulative release achieved in 24 h. inhibitory halo tests, only CLX groups exhibited action against both strains, while QX-P acted against S. aureus. Antibiofilm analyses showed CLX groups with the highest metabolic reduction rates in both strains (± 79%); QX-P groups showed similar reduction rates in both strains, slightly higher for E. coli (60-80%), and QX-C groups had a significant discrepancy between strains: 35-70% for S. aureus and 14-19% for E. coli. In conclusion, material behavior was directly affected by added actives to the polymeric matrix. Proportions of Q or X only affected final thickness. Regarding proposed drug delivery applications, the devices showed great potential, especially CLX and QX-P groups.(AU)

Corrección del artefacto producido en imágenes tomográficas en equipos odontológicos / Correction of the artifact produced in tomographic images in dental equipment

Objetivo: disminuir el efecto de artefacto que generan objetos de alta densidad mediante la utilización de filtros de distintos materiales y espesores, ubicados en lugares estratégicos del tomógrafo. Material y métodos: se utilizaron filtros de aluminio y de cobre ubicados en lugares estratégicos en el equipo tomográfico. Se realizaron cortes oblicuos en piezas dentarias con restauraciones metálicas y en implantes; se midió la extensión del artefacto en ancho y alto en cada adquisición tomográfica. Resultados: se hallaron diferencias significativas respecto a la disminución de la dispersión de acuerdo con cada filtro con respecto a la no utilización de estos elementos. Conclusión: la utilización de filtros logró disminuir el efecto de artefacto en estructuras de alta densidad, obteniendo una mejor calidad de imagen para el diagnóstico, permitiendo que el software pueda reconstruir una imagen real (AU)

Objective: to diminish the artifact effect generated by high density objects by using filters of different materials and thickness, located in strategic places of the tomograph. Material and methods: aluminum and copper filters located in strategic places in the tomographic equipment were used. Oblique cuts were made on dental pieces with metal restorations and implants; the extension of the artifact in width and height was measured in each tomographic acquisition. Results: significant differences were found regarding the decrease of the dispersion according to each filter with respect to the non-use of these elements. Conclusion: the use of filters achieves to diminish the artifact effect in structures of high density, obtaining a better image quality for the diagnosis, allowing the software to reconstruct a real image (AU)

Synthetic Hydroxyapatite Bone Graft Substitute In Sinus Augmentation - A Histological Analysis

Aim: Material And Method:To see the effect of synthetic Hydroxyapatite bone graft substitute in sinus augmentation. A lateral window was cut on the buccal aspect of the maxilla on the posterior region in the area of molar I/II and after carefully lifting the sinus membrane, bone graft was packed and a collagen membrane was placed on top of it. After a period of 8 months the site was re-entered to take bone sample for histological analysis using a trephine, at the same time, implant (Bioner Top DM, 4/10) was placed at the surgical site. The surgical site healed well. G-Bone hasResults: shown good bone growth histologically. The surgical site healed well. G-Bone has shown good bone growthConclusion: histologically.

Protocolo Abreviado Guiado Digital: Técnicas de Marcadores Tisulares, Silicona de Registro y CBCT con Sonrisa / Digitally Guided Abbreviated Protocol: Tissue Marker Techniques, Recording Silicone and CBCT with Smile

Establecer un protocolo de cirugía guiada estática con técnicas referenciales para ser realizado de manera predecible, repetible y simple, en todos los tipos de casos. El protocolo abreviado guiado digital para cirugía guiada estática para implantes se centra en diseñar computacionalmente una guía quirúrgica que se apoye en el tejido remanente del paciente, siendo un protocolo digital versátil para la cirugía y rehabilitación implanto protésica, basada en registros clínicos, principalmente la línea de la sonrisa y la captación de ésta en tomografía de haz cónico (CBCT), además de establecer dimensión vertical oclusal (DVO). Logrando así, planificación de implantes hasta la inserción inmediata de la prótesis temporal. Se ejemplifica el trabajo con 2 casos clínicos. Se establece un protocolo con la intención de que pueda ser realizado en pacientes desdentados parciales (Técnica de Registro Silicona) o totales (Técnica de Marcadores Tisulares en prótesis), definiendo un flujo de trabajo tridimensional, digital y optimizado, con un consecuente ahorro de tiempo clínico. Como principio del protocolo de cirugía guiada es lograr el objetivo quirúrgico - protésico deseado con alta precisión. La cirugía y rehabilitación de implantes de manera convencional es altamente dependiente del operador por lo que la alternativa de cirugía guiada de manera estática es una herramienta más para mejorar el pronóstico del paciente. Se establece un protocolo digital simple y efectivo, de cirugía guiada, para la rehabilitación implanto protésica basada en la línea de la sonrisa, tomografía de haz cónico (CBCT), dimensión vertical oclusal (DVO). Protocolo predecible y que optimiza los tiempos clínicos, logrando una rehabilitación protésica inmediata acorde e individualizada para cada paciente.

Establish a static guided surgery protocol with referential techniques to be performed in a predictable, repeatable and simple way, in all types of cases. The abbreviated digital guided protocol for static guided surgery for implants focuses on computationally designing a surgical guide that rests on the patient's remaining tissue, being a versatile digital protocol for prosthetic implant surgery and rehabilitation, based on clinical records, mainly the line of the smile and its uptake in cone beam tomography (CBCT), in addition to establishing occlusal vertical dimension (OVD). Thus achieving implant planning until the immediate insertion of the temporary prosthesis. The work is exemplified with 2 clinical cases. A protocol is established with the intention that it can be carried out in partially edentulous patients (Silicone Registration Technique) or total (Tissue Marker Technique in prostheses), defining a three-dimensional, digital and optimized workflow, with a consequent saving of time. clinical. As a principle of the guided surgery protocol, it is to achieve the desired surgical-prosthetic objective with high precision. Conventional implant surgery and rehabilitation is highly dependent on the operator, so the alternative of statically guided surgery is one more tool to improve the patient's prognosis. A simple and effective digital protocol for guided surgery is established for prosthetic implant rehabilitation based on the smile line, cone beam tomography (CBCT), and occlusal vertical dimension (OVD). Predictable protocol that optimizes clinical times, achieving an immediate and individualized prosthetic rehabilitation for each patient.

Regulación de la implantología dental en México / Regulation of dental implantology in Mexico

Introducción: los implantes dentales se han convertido en uno de los tratamientos odontológicos con mayor demanda en todo el mundo, no sólo por el nivel máximo de funcionalidad y de estética, sino también debido a su estabilidad, osteointegración y facilidad en su rehabilitación. Es incierto si los implantes dentales se encuentran normados formalmente en México, lo que motiva a la revisión del estado actual. Objetivo: evidenciar el estado actual de la legislación de la práctica de la implantología dental en México a través de una revisión en la literatura. Material y métodos: revisión de las legislaciones existentes en México para la aplicación de implantes dentales y su contraparte en el mundo a través de la evaluación de normas expedidas en América y Europa. Resultados: se contabilizó un total de 17 escuelas de implantes dentales que cuentan con el reconocimiento de la Secretaría de Educación Pública, de las cuales tres son públicas y 14 privadas. Se presentó una discrepancia en los planes de estudio que va de 16 a 36 meses. Las escuelas no contaron con un aval normativo. Las normas internacionales para control de calidad y aplicación de la tecnología en implantes se ubicaron en Canadá, Estados Unidos, España, Reino Unido y Francia. Conclusiones: contar con un antecedente normativo establecido por los países de primer mundo y ausente en México permite evidenciar la necesidad de implementar una Norma Oficial Mexicana que regule la fabricación, distribución y almacenamiento de los implantes dentales en México. A la vez, la revisión sugiere que la Secretaría de Educación Pública norme los créditos mínimos necesarios en las instituciones educativas reconocidas para la formación de recursos humanos que ejercen la implantología dental (AU)

Introduction: dental implants have become one of the dental treatments with the highest demand in the world, not only because of the highest level of functionality and aesthetics, but also because of their stability, osseointegration and ease of rehabilitation. It is uncertain if dental implants are formally regulated in Mexico, which motivates the review of the current status. Objective: to demonstrate the current state of the legislation for the practice of dental implantology in Mexico through a review of the literature. Material and methods: review of the existing legislation in Mexico, for the application of dental implants and its counterpart in the world, through the evaluation of standards issued in America and Europe. Results: a total of 17 dental implant schools that have the recognition of the Ministry of Public Education were counted, of which 3 are public and 14 private. There was a discrepancy in the study plans that ranged from 16 to 36 months. Schools will not have regulatory backing. The international standards for quality control and application of technology in implants were located in Canada, the United States, Spain, the United Kingdom and France. Conclusions: having a normative antecedent established by the countries of the first world and absent in Mexico, allows to demonstrate the need for the implementation of an Official Mexican Standard, which regulates the manufacture, distribution and storage of dental implants in Mexico. At the same time, the review suggests that the Ministry of Public Education regulate the minimum necessary credits in recognized educational institutions, for the training of human resources that practice dental implantology (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.

Research progress on multifunctional natural antioxidants in oral therapies / 口腔疾病防治

@#Oxidative stress is closely associated with the development of oral diseases such as caries, periodontitis and endodontitis. The accompanying oxidative stress during inflammation could aggravate tissue damage. However, numerous studies have shown that some dental materials, such as composite resins, bleach, drugs for root canal irrigation and dental implants, can give rise to abundant free radicals, which have adverse effects on peripheral tissues. Therefore, it is essential to supplement with extra antioxidants against free radicals. Plant-derived natural antioxidants have attracted great attention in biomedicine because of their excellent biocompatibility and easy access. This paper focused on the redox imbalance in the oral cavity and the application of natural antioxidants to oral therapy and their modification of dental materials. Current research shows that by constructing polyphenol-based metal organic nanoenzymes or adding vitamins and polyphenols to bionic hydrogels, the safety and utilization rate of antioxidants can be significantly improved. However, these polymer delivery systems have problems such as poor degradability, hepatotoxicity and nephrotoxicity, and the research is still in its infancy. In terms of material modification, it is crucial to choose the type and ratio of natural antioxidants and raw materials, as well as appropriate modification methods. A strong chemical bond between the antioxidant and the raw material may lead to the failure of antioxidant release from the modified composite, lowering the antioxidant activity. At the same time, the selection of polyphenols rich in pyrogallol functional groups can retain more free phenolic hydroxyl groups after chemical modification, which is conducive to greater antioxidant activity by the implant materials. Although research on natural antioxidants in oral therapy has made progress, there is a lack of data supporting clinical trials and long-term application effects, and further research is still needed.

Progress of research on bone grafts for implant dentistry / 口腔医学

@#With the development of dental implant techniques, dental rehabilitation of partially or totally edentulous patients with oral implants has become a common practice. Adequate bone volume in the implant area is a key factor for the success of implant restoration. However, insufficient bone volume in the implant area is very common in clinical practice, which jeopardizes the structural, functional, and esthetic outcomes of implant treatment. Bone augmentation with bone grafts is one of the methods commonly used in clinical practice to meet the requirements of implantation. Properties of bone grafts, such as biocompatibility,osteoconduction, osteoinduction and osteogenesis, are important to the success of bone augmentation. This paper reviews current research on dental bone grafts about their clinically relevant capabilities, classification and their potential development in the future, in order to provide theoretical reference for clinical application of bone grafts and successful implant restoration.

Multi-disciplinary treatment of severe palatal radicular groove of maxillary lateral incisor: A case report and literature review / 中南大学学报(医学版)

Palatal radicular groove is a developmental malformation of maxillary incisors, lateral incisors in particular, which often causes periodontal destruction. This paper reports a case of combined periodontal-endodontic lesions induced by palatal radicular groove, which was initially misdiagnosed as a simple periapical cyst. After root canal therapy and periapical cyst curettage, the course of disease was prolonged, resulting in the absence of buccal and maxillary bone plates in the affected tooth area. After the etiology was determined, the affected tooth was extracted and guide bone tissue regeneration was performed at the same time, followed by implantation and restoration at the later stage, leading to clinical cure. The palatal radicular groove is highly occult, and the clinical symptoms are not typical. If the abscess of the maxillary lateral incisor occurs repeatedly, and the abscess of the maxillary lateral incisor has not been cured after periodontal and root canal treatment, cone-beam computed tomographic and periodontal flap surgery should be considered.

Accuracy of selective laser sintered computer guided stents versus digital light processing stents in immediate implant placement in esthetic zone: a randomized controlled trial / Precisão de stents sinterizados por laser seletivo guiados por computador versus stents de processamento de luz digital na colocação imediata de implantes em região estética: um ensaio randomizado

Objective: To compare accuracy of selective laser sintered computer guided stents versus digital light processing stents in immediate implant placement in esthetic zone. Material and Methods: The patients were selected according to the eligibility criterias. The selected patients were randomly allocated to either digital light processing stents (test group) or selective laser sintered computer guided stents (control group). Proper examination and diagnostic records were done for each patient followed by triple scan protocol with cone beam computer tomography (CBCT). Planning and construction of tooth supported computer guided surgical stent was done by either digital light processing technique for test group or selective laser sintering for control group. Twenty implants were inserted following computer guided implant placement protocol. After post-operative CBCT pre and post images were merged using blue sky bio software. Linear and angular deviations between planned implant and actual implant positions were measured. Results: Tests were considered statistically significant if the p- value was less than 0.05. Difference in means were calculated for the analysis of continuous variables with corresponding 95% confidence intervals. There was no statistical difference between selective laser sintering and digital light processing groups in all measured terms. Conclusion : Within the limitations of this study, both techniques can be used for immediate implant placement with clinically satisfactory results decreasing the positional errors associated with immediate implant placement. (AU)

Objetivo: Comparar a acurácia de stents sinterizados por laser seletivo guiados por computador versus stents de processamento de luz digital na colocação imediata de implantes em região estética. Material e Métodos: Os pacientes foram selecionados de acordo com os critérios de elegibilidade. Os pacientes selecionados foram distribuídos aleatoriamente nos seguintes grupos: stents de processamento de luz digital (grupo experimental) ou stents sinterizados por laser seletivo guiados por computador (grupo controle). Os registros dos exames adequados e diagnósticos foram realizados para cada paciente seguido por um protocolo de varredura tripla com tomografia computadorizada de feixe cônico (TCFC).O planejamento e a construção do Stent cirúrgico guiado por computador com suporte dentário foram feitos pela técnica de processamento de luz digital para o grupo experimental ou sinterização a laser seletivo para o grupo controle. Vinte implantes foram inseridos seguindo o protocolo de colocação de implante guiado por computador. Após a TCFC pós-operatória, as imagens pré e pós foram mescladas usando o software blue sky bio. Foram medidos os desvios lineares e angulares entre o implante planejado e as posições reais do implante. Resultados: Os testes foram considerados estatisticamente significativos se o valor de p fosse menor que 0,05. A diferença nas médias foi calculada para a análise das variáveis contínuas com intervalos de confiança de 95%. Não houve diferença estatística entre os grupos de sinterização a laser seletivo e processamento digital de luz em todos as variáveis mensuradas. Conclusão: Dentro das limitações deste estudo, ambas as técnicas podem ser utilizadas para colocação imediata de implantes com resultados clinicamente satisfatórios diminuindo os erros posicionais associados colocação imediata de implantes. (AU)

Dental implant treatment in vascularized bone flaps after jaw reconstruction / 华西口腔医学杂志

Jaw defects caused by various reasons often seriously affect appearance and function. The goal of the treatment of oral and maxillofacial tumors should include the cure of the tumor and the restoration of premorbid function. The development of microsurgery and digital surgery technology has promoted the development of jaw reconstruction with vascularized free bone flap. Good appearance and improved predictability could be obtained with the help of preope-rative visual design. How to rehabilitate occlusal function on the reconstructed jaw and improve the quality of life of patients has become an important research direction. This article discusses the challenge of jaw reconstruction, the selection of vascularized bone flap, the choice of implant timing, the treatment of peri-implant soft tissue, and the influence of radiotherapy on implants after jaw reconstruction.

Applications of Hyaluronic Acid (HA) in Dental Implant Treatment: A Systematic Review

@#Introduction: Hyaluronic acid (HA) has a long history and is widely used in cosmetics, medicine, and dermatology. This molecule is still considered relatively new in the field of dentistry. This study aimed to assess the application of HA in dental implant treatment. Method: Search in the multiple indexed databases such as Pubmed, COCHRANE, and Scopus was conducted up until August 2022 using the keywords “hyaluronic acid”, “hyaluronan,” and “dental implant.” Results: The literature search identified 816 articles, and 17 were selected in this study. Three domains of use of HA in dental implant treatment were identified: surface modification of implant surface, treatment after insertion of a dental implant, and bone graft/membrane material. There are eight randomized control trials and nine non-randomized control trials included in this study. Only six studies showed statistically significant results with HA groups. Conclusion: Overall, there are positive findings on the application of HA in dental implant treatment, showing it can be used in dental implantology, with multiple categories of uses.

PHOTOBIOMODULATION IN DENTAL IMPLANT THERAPY: A REVIEW

Photobiomodulation (PBM) or formerly known as low-level laser therapy (LLLT) is nothing but low-dosage biophotonics for therapy which presents an advancing new era of regenerative modalities in dental implantology. It utilizes light emitting diodes (LEDs), broad light sources and lasers for this purpose. Photobiomodulation is intended for relieving pain and inflammation, regulating immune responses as well as stimulating wound healing and tissue regeneration. This helps in combatting the main pathological causes of implant failures that are, peri-implant mucositis and peri-implantitis as well as helps promote osseointegration and improve stability of implants. While the scope of photobiomodulation has been thoroughly investigated in in-vitro and animal studies, human clinical trials are still scarce which makes appropriate protocol formation with respect to dosage and mode of delivery among other parameters difficult. A recently introduced and potential application of photobiomodulation in the field of implantology aims to deliver the positive effects of biophotonics through in-situ ambulatory PBM therapy called the smart dental implant (SDI) system. This comprehensive review presents the current and future trends in the application of photobiomodulation in the field of dental implantology.

Influence of abutment angulation on implant failure in immediately placed and restored implants in the esthetic zone: a randomized clinical trial

Background: Tooth extraction socket in the aesthetic area is a major indication for immediate implant placement greatly improving patient satisfaction and preserving the alveolar ridge. However, the effect of non-axial force on the peri-implant bone with subsequent early implant failure remains unclear. Objective:Evaluate the prognosis of tilted implants immediately placed and restored with angled abutments in comparison to straight implants restored with straight abutments in the esthetic area (anterior or premolars) using computer-aided surgical guides. Material and methods: Badly decayed non-restorable teeth in the aesthetic zone (anterior or premolars) were extracted atraumatically. Immediately after guided implant insertion, the abutments were adjusted and placed according to the allocation group (0, 15, or 25-degree angle) then a temporary crown was performed out of occlusion in centric and eccentric relation. Early implant failure was assessed at three and six months. Results:There was no statistically significant difference between the two groups (P=0.305). Straight and angled abutment groups showed 6 (14.3%) and 8 (20%) failed cases, respectively. The post-hoc subgroup analysis showed no statistically significant difference between angle 15 and angle 25 degree groups where (P=0.686) or between Anterior and Premolar groups (P=0.853). Conclusion: There was no statistically significant difference in the failure rate when comparing angled to straight immediately placed & restored implants. This applies to both anterior and premolar implants

The assessment of periimplant soft tissue condition with morse taper abutment connection: a rapid review

Aim: This study aims to evaluate the clinical assessment results of periimplant soft tissue with morse taper (internal abutment connection). Methods: The study was conducted using a rapid review by searching the articles from PubMed NCBI and Cochrane by using keywords. All articles were selected by the year, duplication, title, abstract, full-text, and finally, all selected articles were processed for final review. Following clinical parameters were included; Periimplant Probing Pocket Depth (PPD), Plaque Score (PS), modified Plaque Index (mPI), Mucosal Thickness (MTh), Gingival Height (GH), periimplant mucosal zenith, Pink Esthetic Score (PES), Bleeding On Probing (BOP), Sulcus Bleeding Index (SBI), and modified Gingival Index (mGI). Results: 9 selected articles were obtained from the initial literature searching count of 70 articles. The overall samples included 326 morse taper implants. Based on the evaluation, 3 out of 4 articles reported pocket depth < 4 mm, no bleeding was reported in 2 out of 4 articles. 4 out of 4 articles reported low plaque accumulation, low soft tissue recession was reported in 3 out of 3 articles, and 4 out of 4 articles reported acceptable PES values. Conclusion: The evaluations indicate that the morse taper (internal abutment connection) has favorable assessment results based on various clinical parameters

Importancia de la apertura bucal para cirugía guiada de implantes dentales. Reporte de caso y recomendaciones

La cirugía guiada asistida por computadora consiste en la fabricación de una guía quirúrgica mediante un protocolo digital que nos brinda diversos beneficios a la hora de colocar los implantes dentales; sin embargo, no todos los pacientes son candidatos para operar con este procedimiento, especialmente en el sector posterior debido a las limitaciones de la apertura bucal. En el presente caso, incluimos en el protocolo completo el registro de las dimensiones de apertura bucal del paciente como requisito previo al flujo de trabajo digital, como un elemento importante en la toma de decisión previa a la planificación para la fabricación de la guía quirúrgica. Adicionalmente, según el contexto, brindamos recomendaciones para tener en cuenta con respecto a la apertura bucal mínima suficiente para la colocación de implantes de diferentes longitudes mediante el protocolo guiado Straumann®.

Computer-guided surgery consists of the manufacture of a surgical guide using a digital protocol that provides various benefits when placing dental implants; however, not all patients are candidates to be operated with this procedure, especially in the posterior sector due to the limitations of the mouth opening. In the present case, the recording of the patient's mouth opening dimensions was included in the complete protocol as a prerequisite to the digital workflow, as an important element in the decision-making prior to the planning for the manufacture of the surgical guide. In addition, depending on the context, we provide recommendations to consider regarding the sufficient minimum mouth opening for the placement of implants of different lengths using the Straumann® Guided Protocol.

Uso de antibióticos para instalación de implantes óseo integrados

Introducción: La extracción de dientes permanentes se puede deber a varias razones, como la caries dental, enfermedad periodontal, entre otras. Frente a este problema, surgen los implantes dentales, definidos como un dispositivo protésico aloplástico implantado en el tejido óseo, proporcionando retención y soporte para una prótesis dental fija o removible. A pesar de la alta tasa de éxito, existen fracasos en implantología, a causa de una infección postoperatoria. Es por esto, que se han incluido dentro del tratamiento distintos regímenes de terapias antibióticas, sin embargo, actualmente su efectividad para evitar complicaciones peri y postoperatorias es controversial. Métodos: Realizamos una búsqueda en Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante el cribado de múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, analizamos los datos de los estudios primarios, realizamos un metaanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. Resultados y conclusiones: Identificamos 23 revisiones sistemáticas que en conjunto incluyeron 16 estudios primarios, de los cuales, 9 corresponden a ensayos aleatorizados. Concluimos que la terapia antibiótica pre operatoria en comparación a placebo probablemente reduce el fracaso de los implantes y de las prótesis, sin embargo, puede generar poca o nula diferencia en las infecciones postoperatorias. Por otro lado, no está claro si el tratamiento de terapia antibiótica (perioperatoria y postoperatoria) en comparación a placebo reduce el fracaso de los implantes y de infección postoperatoria, debido a que la certeza de la evidencia existente es muy baja.

Introduction: The extraction of permanent teeth can be due to various reasons, such as dental caries, periodontal disease, among others. Faced with this problem, dental implants arise, defined as an alloplastic prosthetic device implanted in bone tissue, providing retention and support for a fixed or removable dental prosthesis. Despite the high success rate, there are failures in implantology, due to postoperative infection. For this reason, different antibiotic therapy regimens have been included in the treatment; however, their effectiveness in avoiding perioperative and postoperative complications remains controversial. Methods: A search was performed using Epistemonikos, the biggest database for systematic reviews in health, which is maintained by screening of multiple sources of information, including MEDLINE, EMBASE, Cochrane, among others. Data from systematic reviews were extracted, and analysis of the primary studies was performed, including a meta-analysis and a summary of findings table using GRADE approach. Results and conclusions: We identified 23 systematic reviews that together included 16 primary studies, of which 9 correspond to randomized clinical trials. We conclude that antibiotic prophylaxis compared to placebo probably reduces implant and prosthetic failure, however, it may make little or no difference in postoperative infections. On the other hand, it is not clear whether antibiotic therapy treatment (perioperative and postoperative) compared to placebo reduces implant failure and postoperative infection, because the certainty of the existing evidence is very low.

Peri-implant clinicoradiographic status among betel-quid chewers and controls

Abstract The aim of the present case-control observational study was to evaluate the peri-implant clinicoradiographic status among betel-quid chewers and controls. Self-reported betel-quid chewers and controls were included. Participants were categorized into 3 groups: Group-1: Individuals chewing betel-quid with tobacco; Group-2: Individuals chewing betel-quid without tobacco; and Group-3: Controls (individuals not using tobacco in any form). Demographic data was collected using a questionnaire. Periodontal and peri-implant clinicoradiologic parameters (plaque and gingival indices [PI and GI], probing depth [PD] and crestal bone loss/marginal bone loss [CBL/MBL]) were assessed. Clinical attachment loss (AL) around teeth was also assessed. Group comparisons were done using the one-way analysis of variance and Bonferroni Post-hoc adjustment tests. Correlation of periodontal and peri-implant inflammatory parameters with the duration of betel-quid chewing habit and duration of placement in the mouth were assessed using logistic regression analysis. P<0.05 was considered statistically significant. Thirty, 30 and 30 patients were included in groups 1, 2 and 3, respectively. Full-mouth PI (P<0.01), GI (P<0.01), clinical AL (P<0.01), PD (P<0.01) and mesial and distal MBL (P<0.01) were higher in groups 1 and 2 than Group-3. Peri-implant mPI (P<0.01), mGI (P<0.01), PD (P<0.01) and MBL/CBL (P<0.01) were significantly higher in groups 1 and 2 than Group-3 with no significant difference in groups 1 and 2. Betel-quid chewing habit either with or without tobacco is a risk-factor of peri-implant soft-tissue inflammation and CBL.

Resumo O objetivo do presente estudo observacional de casos-controles foi avaliar o estado clínico-radiográfico periimplantar dos usuários de bétele. Foram incluídos usuários que relataram utlizar a substância bétele como tabaco de mascar. Os participantes foram categorizados em 3 grupos: Grupo-1: Indivíduos que mascam bétele com tabaco; Grupo-2: Indivíduos que mascam bétele sem tabaco; e Grupo-3: Controle (indivíduos que não usam tabaco sob qualquer forma). Os dados demográficos foram recolhidos utilizando um questionário. Foram avaliados parâmetros clínico-radiográfico e periimplantares (índices placa e gengivais [IP e IG], profundidade de sondagem [PS] e perda de crista óssea/ perda óssea marginal [PCO/POM]). Também foi avaliada a perda inserção clínica (IC) em torno dos dentes. As comparações de grupo foram feitas utilizando a análise de variância unidireccional e os testes de ajustamento post-hoc de Bonferroni. A correlação dos parâmetros inflamatórios periodontais e periimplantares com a duração do hábito de mastigação da bétele e duração da colocação na boca foi avaliada utilizando a análise de regressão logística. P<0,05 foi considerado estatisticamente significativo. Foram utilizados 30 pacientes em cada grupo. O IP de boca inteira (P<0,01), IG (P<0,01), IC clínica (P<0,01), PS (P<0,01) e POM mesial e distal (P<0,01) foram mais elevados nos grupos 1 e 2 do que no grupo 3. O mPI peri-implantar (P<0,01), '(P<0,01), PD (P<0,01) e POM/PCO (P<0,01) foram significativamente mais elevados nos grupos 1 e 2 do que no grupo 3, sem diferença significativa nos grupos 1 e 2. O hábito de mastigar a substância bétele com ou sem tabaco é um fator de risco de inflamação dos tecidos moles periimplantares e PCO.