Orientações de manutenção e higienização de prótese fixa total implantossuportada: revisão de literatura / Guidelines for maintenance and cleaning of implantssupported total fixed prosthesis: literature review

A evolução dos tratamentos em implantodontia possibilitou uma mudança nos tratamentos reabilitadores para pacientes edêntulos, tornando possível a colocação de próteses fixas, que proporcionam maior qualidade de vida para estes pacientes. Para que estas próteses tenham bom desempenho e longevidade satisfatórios é essencial que se mantenha um padrão adequado de higienização bucal e manutenção profissional. Assim, o objetivo deste trabalho foi realizar uma revisão de literatura a respeito dos principais recursos disponíveis para higienização e manutenção das próteses totais fixas sobre implante (protocolo de Branemark), tanto nos cuidados domiciliares dos pacientes quanto no atendimento profissional do cirurgião dentista. Foi realizada uma busca eletrônica, não sistemática, nas bases de dados Lilacs, Pubmed/Medline, Scielo e ScienceDirect, cruzando-se os seguintes descritores: "Higiene Oral"; "Implantes Dentários"; "Implantação Dentária"; "Manutenção"; "Prótese Dentária Fixada por Implante" e "Prótese Dentária". Foram consultados artigos de revisão de literatura, revisão sistemática, meta-análise, estudos clínicos randomizados, além de livros pertinentes ao assunto, publicados no período de 1995 a 2022.Verificou-se na literatura disponível que os principais instrumentos indicados para uso domiciliar são escova dental, fio dental, escova interdental, irrigador oral, dentifrício e enxaguatório. No atendimento profissional em consultório odontológico deve ser dispendida atenção especial às instruções passadas ao paciente e também fazer o possível para motivar e encorajar o seu engajamento na rotina de higienização, além do acompanhamento periodontal, possíveis substituições de parafusos e instalação de placa oclusal estabilizadora, quando necessário. Manter uma higiene oral adequada é essencial para o sucesso das próteses fixas sobre implantes e o cirurgião dentista desempenha um papel crucial não apenas ao realizar o acompanhamento periódico do paciente, mas também ao sugerir os instrumentos mais apropriados, instruir sobre a higiene oral adequada e motivar o paciente a manter a saúde bucal satisfatória(AU)

The evolution of treatments in implantology has enable a change in rehabilitation treatments for edentulous patients, making it possible to place fixed prostheses that provide a better quality of life for these patients. In order to ensure good performance and satisfactory longevity, it is essential to maintain an appropriate standard of oral hygiene and professional maintenance. Thus, the objective of this work was to conduct a literature review on the main resources available for cleaning and maintenance of complete fixed prostheses on implants (Branemark protocol), both in the patients' home care and in the professional care provided by the dentist. A nonsystematic electronic search was carried out in the Lilacs, Pubmed/Medline, Scielo, and ScienceDirect databases, crossing the following descriptors: "Oral Hygiene"; "Dental Implants"; "Dental Implantation"; "Maintenance"; "Dental Prosthesis, ImplantSupported"; and "Prosthodontics". Literature review articles, systematic reviews, meta-analyses, randomized clinical studies, and relevant books on the subject published from 1995 to 2022 were consulted. The literature available indicates that the main instruments recommended for home care are toothbrush, dental floss, interdental brush, oral irrigator, toothpaste, and mouthwash. In the professional dental office, special attention should be given to the instructions given to the patient, as well as to motivate and encourage their engagement in the hygiene routine, in addition to periodontal monitoring, possible screw replacements, and installation of an occlusal splint when necessary. Maintaining adequate oral hygiene is essential for the success of fixed prostheses on implants, and the dentist plays a crucial role, not only in providing periodic patient follow-up, but also in suggesting the most appropriate instruments, instructing on adequate oral hygiene, and motivating the patient to maintain satisfactory oral health(AU)

Periradicular and Peri-Implant Lesions Associated with Apical Impact of Osseointegrated Implants in Tooth Roots: Clinical Case Reports

This clinical case report aims to describe the development of periradicular and perimplant cystic lesions resulted from the intimate contact of the apical region of osseointegrated implants of dental roots, and discuss the reasons fo r failure of the guided bone regeneration procedure associated with platelet rich fibrin and leukocytes, this process was used to the treatment of the first case. Case Reports. Three cases were reported, two cases described the close contact between the tooth roots and the osseointegrated implants and another with a distance of 1.08 mm. All cases realized a radiographic, and they had not periapical lesions before contact with the apical region of the osseointegrated implants on the roots of the teeth. In the case with the largest cystic extension, the procedure was: removal of the osseointegrated implant with apicectomy of the neighboring teeth, excisional biopsy of the lesion, and grafting using the technique of guided bone regeneration associated with L-PRF. All three cases, endodontic treatment was performed on the neighboring teeth within 2 years of survival of the osseointegrated implants in order to reverse the existing lesion. Results. The diagnostic hypothesis of the three cases was periradicular and peri-implant lesion, arising from a contact of the apical region of the osseointegrated implant with the adja cent tooth. The distance of 1.08 mm between the apices did not ensure normality of the periradicular and peri-implant tissues. The intimate contact caused lesions of different extents and root fractures. Conclusion. Premature contact of the osseointegrated implant with the root region of the neighboring tooth may lead to the development of periradicular and peri-implant lesions, suggesting that it is not possible to control this infectious process with endodontic treatment of the injured tooth.

Este reporte de caso clínico tuvo como objetivo describir el desarrollo de lesiones quísticas perirradiculares y periimplantarias resultantes del contacto íntimo de la región apical de implantes osteointegrados de raíces dentales, y además discutir las razones del fracaso del procedimiento de regeneración ósea guiada asociado a fibrina rica en plaquetas y leucocitos. Este proceso se utilizó para el tratamiento del primer caso. Se reportaron tres casos, en dos casos se describieron el estrecho contacto entre las raíces de los dientes y los implantes osteointegrados y en el otro se determinó una distancia de 1,08 mm. En los tres casos se realizó una radiografía y se determinó que no existían lesiones periapicales, antes del contacto con la región apical de los implantes osteointegrados, en las raíces de los dientes. En el caso de mayor extensión quística, el procedimiento fue: extracción del implante osteointegrado con apicectomía de los dientes vecinos, biopsia excisional de la lesión e injerto mediante la técnica de regeneración ósea guiada asociada a L-PRF. En los tres casos, el tratamiento de endodoncia se realizó en los dientes vecinos dentro de los 2 años de supervivencia de los implantes osteointegrados para revertir la lesión existente. La hipótesis diagnóstica de los tres casos fue lesión perirradicular y periimplantaria, originada por un contacto de la región apical del implante osteointegrado con el diente adyacente. La distancia de 1,08 mm entre los ápices no aseguraba la normalidad de los tejidos perirradiculares y periimplantarios. El contacto íntimo provocó lesiones de diferente extensión y fracturas radiculares. El contacto prematuro del implante osteointegrado con la región radicular del diente vecino puede conducir al desarrollo de lesiones perirradiculares y periimplantarias, lo que sugiere que no es posible controlar este proceso infeccioso con tratamiento endodóntico del diente lesionado.

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)

Late Bilateral Sequential Cochlear Implant and Quality of Life

Abstract Introduction Hearing impairment is one of the main disorders that can interfere with the development of speech and language. In an individual, it can cause significant communication difficulties, social isolation, negative feelings, and depressive disorders. The hearing aids (HAs) and cochlear implant (CI) are options for profound and severe hearing loss, and the CI can be indicated for individuals who do not obtain benefits from HAs. Objective To evaluate the quality of life of individuals who underwent sequential bilateral CIs with a long surgical interval between procedures. Methods Fifteen patients, aged 8 to 70 years old, who underwent sequential bilateral CI, with an interval ≥ 4 years between surgeries, were evaluated. Quality of life was evaluated using three questionnaires: WHOQOL-BREF, SSQ-12 and HHIA in Portuguese. Results The WHOQOL-BREF questionnaire showed that the study participants had a good quality of life in all domains assessed. According to the SSQ-12, few reported inability to listen in communication situations. Most individuals were classified as having medium disability by the HHIA, but the social and emotional effects did not significantly affect the quality of life. Conclusion The use of questionnaires to assess the quality of life of patients with hearing impairment is a valuable tool to measure adaptation to CI. Patients undergoing bilateral sequential CI, even with a long interval between procedures, presented high indices of quality of life.

Total removal of the buccal flange in maxillary prosthetic preparation: a necessity?: case report / Remoção total do flange vestibular no preparo protético de maxila: uma necessidade?: relato de caso

ABSTRACT Fixed implant-supported complete maxillary dentures aim to rehabilitate aesthetic, phonetic, and functional aspects of edentulous arches. A previous prosthetic preparation without a flange in the anterior sector makes it possible to evaluate the labial support and the existing space for the future prosthesis. Thus, it allows the most appropriate choice of the type of rehabilitation and surgical technique. However, follow-up studies have shown that when proceeding this way, problems in the posterior sector are still occurring, such as the lack of vertical space for an adequate bar design and concave internal designs, which make access to hygiene difficult. Faced with the problem, the aim of this study is to report a clinical case in which the previous prosthetic preparation included the removal of the flange also from the posterior sector during the teeth try-in and the duplication of this assembly in a transparent multifunctional guide that allowed the visualization of the amount of bone removal needed. The osteotomy, performed before the installation of the implants, provided enough space for the bar, acrylic, and prefabricated denture teeth in the prosthesis that was installed, an important fact considering that this is an area with greater chewing efforts. It also allowed for correct internal design in the prosthesis, which will ensure access to correct hygiene. Based on the analysis of the rehabilitated case, it seems fair to conclude that the total removal of the buccal flange at the time of testing the wax try-in of the teeth and its duplication is a differential in the approach of cases and should always be adopted to ensure a lower margin of error and greater longevity in the proposed rehabilitative treatment.

RESUMO Próteses totais fixas implantossuportadas objetivam reabilitar arcos edêntulos nos aspectos estético, fonético e funcional. Um preparo protético prévio sem flange no setor anterior permite avaliar o suporte labial e o espaço presente para a futura prótese, auxilinado na escolha do tipo de reabilitação e da técnica cirúrgica mais adequada. No entanto, estudos de acompanhamento tem mostrado que ao proceder dessa maneira ainda estão ocorrendo problemas no setor posterior, como falta de espaço vertical para um desenho adequado da barra e desenhos internos côncavos, que dificultam o acesso à higienização. Frente ao problema, o objetivo do presente trabalho é relatar um caso clínico no qual o preparo protético prévio incluiu a remoção do flange também do setor posterior durante a prova dos dentes e a duplicação dessa montagem em um guia multifuncional transparente permitindo a visualização da quantidade de remoção óssea necessária. A osteotomia, realizada antes da instalação dos implantes, proporcionou espaço suficiente para a barra, acrílico e dentes de estoque na prótese que foi instalada, fato importante considerando ser essa uma zona com maiores esforços mastigatórios. Também permitiu a confecção de desenho interno correto na prótese, que garantirá o acesso para correta higiene. Com base na análise do caso reabilitado, parece lícito concluir que a remoção total do flange vestibular no momento da prova dos dentes em cera e sua duplicação é um diferencial na abordagem dos casos e que deveria sempre ser adotada para garantir menor margem de erros e maior longevidade no tratamento reabilitador proposto.

Evaluation of the treatment effect on sinus elevation and implant restoration in cases with odontogenic maxillary sinusitis after tooth extraction / 口腔疾病防治

Objective@#To investigate the clinical effects of sinus elevation surgery and implant restorationdue to insufficient bone massafter tooth extraction in patients with odontogenic maxillary sinusitis (OMS) and to provide a reference for use in clinical practice.@*Methods@#This study was reviewed and approved by the Ethics Committee, and informed consent was obtained from the patients. Forty-five teeth were extracted from patients with OMS in the maxillary posterior area (the study group). Sinus elevation and implantation were performed due to insufficient bone height in the implant area 6-8 months after tooth extraction in the study group. Forty-eight teeth were extracted from patients without "OMS" in the maxillary posterior area (the control group), and sinus elevation and implantation were performed due to insufficient bone height in the implant area 6-8 months after tooth extraction inthe control group. In the study group, 13 cases of discontinuous maxillary sinus floor bone and residual alveolar bone height of the maxillary sinus floor less than 4 mm were addressed with lateral wall sinus elevation, and the other 32 cases were addressed with crest-approach sinus elevation. In the control group, 8 cases of residual alveolar bone height less than 4 mm in the maxillary sinus floor were addressed with lateral wall sinus,and the other 40 cases were addressed with crest approach sinus elevation. Restorations were placed 6 to 8 months after surgery. The patients were followed up 21 days, 3 months, and 8 months after implantation and every 6 months after the placement of the restorations. The sinus bone gain (SBG), apical bone height (ABL) and marginal bone loss (MBL) were statistically analyzed 24 months after the restoration.@*Results@#The average preoperative mucosal thickness in the 45 patients in the study group was (1.556 ± 0.693) mm, which was significantly larger than that in the control group (1.229 ± 0.425) mm (P<0.001). There were no perforations in either group. Twenty-four months after restoration, there was no significant difference in the SBG, ABH or MBL between the two groups (P>0.05).@*Conclusion@#After the extraction of teeth from patients with OMS, the inflammation of the maxillary sinus decreased, and the bone height and density in the edentulous area were restored to a certain degree. The effects of sinus floor lifting surgery and implant restoration do not differ between patients with and without OMS.

Effect of miniscrew placement height on the distribution of biological forces produced by clear aligner for mandibular molar distalization / 口腔疾病防治

Objective@#To explore the effect of different miniscrew placement heights on the distribution of biological forces produced by clear aligner combined with intramaxillary traction for mandibular molar distalization, to identify the miniscrew location that is conducive to the protection of lower anterior tooth anchorage and to provide a reference that can be used when designing clinical treatments.@*Methods@#Mimics, GeomagicStudio 2017, SolidWorks 2016, and Ansys workbench were used to establish finite element analysis models and perform mechanical analysis under the following six working conditions: working condition 1 was the control group without miniscrews; working conditions 2 to 5 had miniscrew in the buccal bone cortex between the first and second molars of the lower jaw 10 mm, 7 mm, 4 mm, and 1 mm from the top of the alveolar crest, respectively; working condition 6 had the miniscrew in the center of the buccal tongue at the anterior edge of the ascending branch of the lower jaw 5 mm above the occlusal plane.@*Results@#On the sagittal axis, miniscrew anchorage caused distal displacement of all teeth. Compared to the control group, in the miniscrew group, the displacement of the anterior molars exceeded that of the second molars. On the vertical axis, the result in the control group was similar to backward bending; the results in the miniscrew groups resembled the effect of a lever, lowering the lateral incisors and canines and raising the central incisors and first premolars. On the coronal axis, the second premolars and the first molars showed lingual displacement in the control group, and only the premolars and first molars showed lingual displacementin the miniscrew groups. The canines were the teeth that were most strongly affected by the change in miniscrew placement height.@*Conclusion@#The higher the miniscrew position is, the stronger the protective effect on the anterior anchorage. According to the miniscrew placement height, the mandibular arch should be properly narrowed, the central incisors and first premolars should be lowered, and the lateral incisors and canines should be raised when designing clinical treatments.

Effect of electrochemically dealloying Ti6Al4V abutments on human gingival fibroblasts / 口腔疾病防治

Objective@#To investigate the effects of electrochemically dealloying of Ti6Al4V abutments on human gingival fibroblasts (HGFs) and to provide experimental evidence for surface modification of implant abutments.@*Methods@#The samples were divided into an NC group (negative control, no other treatment on a smooth surface), an NM-1 group (nanomesh-1, electrochemical dealloying treatment in 1 mol/L NaOH 1 h on 2 V voltage), and an NM-2 group (nanomesh-2, electrochemical dealloying treatment in 5 mol/L NaOH 1 h on 2 V voltage). The surface morphologies of the samples and the adhesion of HGFs on the sample surfaces were observed with scanning electron microscopy (SEM). The surface hydrophilicities of the samples were measured with a contact angle measuring instrument. The proliferation of HGFs on the different samples were evaluated with CCK-8, and the expression of adhesion-related genes, including collagen Ⅰ (COL1A1), collagen Ⅲ (COL3A1), fibronectin 1 (FN1), focal adhesion kinase (FAK), vinculin (VCL), integrin α2 (ITGA2), and integrin β1 (ITGB1), on the different samples was measured with qRT-PCR. The expression of vinculin on the surfaces of HGFs was observed via confocal laser scanning microscopy (CLSM) after immunofluorescent staining. Collagen fiber secretion and syntheses of HGFs from different samples were evaluated via Sirius red staining.@*Results@#SEM revealed the formation of ordered and uniform three-dimensional mesh structures on the surfaces of the NM-1 and NM-2 groups, with grid diameters of approximately 30 nm for the NM-1 group and approximately 150 nm for the NM-2 group. Compared with that of the NC group, the water contact angles of the NM-1 group and NM-2 groups were significantly lower (P<0.000 1). Cell proliferation in the NM-1 group was significantly greater than that in the NC group (P<0.01). Moreover, there was no significant difference in the water contact angles or cell proliferation between the NM-1 group and the NM-2 group. SEM revealed that HGFs were adhered well to the surfaces of all samples, while the HGFs in the NM-1 and NM-2 groups showed more extended areas, longer morphologies, and more developed pseudopodia than did those in the NC group after 24 h. qRT-PCR revealed that the expression levels of the adhesion-related genes COL1A1, COL3A1, FN1, FAK and VCL in the NM-1 group were significantly greater than those in the NC and NM-2 groups (P<0.01). The expression of vinculin protein in the NM-1 group was the highest, and the number of focal adhesions was greatest in the NM-1 group (P<0.01). The results of Sirius red staining showed that the NM-1 group had the highest secretion and syntheses of collagen fibers (P<0.000 1).@*Conclusion@#The three-dimensional nanomechanical structure of Ti6Al4V modified by electrochemical dealloying promoted the adhesion, proliferation, collagen fiber secretion and syntheses of HGFs, and electrochemical dealloying of Ti6Al4V with a grid diameter of approximately 30 nm obviously promoted HGF formation.

Application of the plasmatrix in alveolar ridge preservation / 口腔疾病防治

@#After tooth extraction, significant absorption occurs in the soft and hard tissues of the alveolar ridge. The goal of alveolar ridge preservation is to maintain the volume and shape of the alveolar ridge's soft and hard tissues as much as possible so as to provide suitable conditions for implant placement. Currently, there are challenges in classifying the socket for alveolar ridge preservation, such as the difficulty in directly guiding the selection of graft materials and clinical procedures and the insufficient space for particle xenograft maintenance, resulting in poor bone regeneration. Plasmatrix is an autologous blood derivative that effectively enhances tissue regeneration. This article introduced the characteristics of soft and hard tissue defects after tooth extraction and the primary applications of plasmatrix for alveolar ridge preservation (liquid plasmatrix, solid plasmatrix membrane/plug, and plasmatrix bone blocks) as well as the proposed methods for the reclassification of sockets for alveolar ridge preservation based on soft and hard tissue defects at the extraction site to facilitate the creation of clinical recommendations. The proposed classifications are as follows: Class I, extraction socket without bone defect, with or without soft tissue defect; Class Ⅱ, extraction socket with bone defect, both sides with bone wall defect less than 50%, with or without soft tissue defect; Class Ⅲ, extraction socket with bone tissue defect, at least one side with bone wall defect greater than 50%, with or without soft tissue defect. For the Class I socket, a solid plasmatrix membrane or plug is inserted, followed by injection of liquid plasmatrix, using a double-layer solid plasmatrix membrane for socket closure; for the ClassⅡ socket, plasmatrix bone blocks are inserted, followed by injection of liquid plasmatrix and secondary solidification, using absorbable collagen membrane and double-layer solid plasmatrix membrane for socket closure; for the ClassⅢ socket, tenting screws are used to maintain height, followed by implantation of plasmatrix bone blocks, injection of liquid plasmatrix and secondary solidification, using absorbable collagen membrane and double-layer solid plasmatrix membrane for socket closure. The aim of this article is to provide comprehensive knowledge of plasmatrix for oral clinicians to serve as a reference to simplify the clinical decision-making process and procedures for alveolar ridge preservation.

CBCT analysis of the relative position between maxillary central incisors and alveolar bone in Southern Chinese adults / 口腔疾病防治

Objective@#Exploring the position and bone wall thickness characteristics of the maxillary central incisors in Southern Chinese adults to provide a clinical reference for the design of immediate maxillary central incisor implantation surgery.@*Methods@#The hospital ethics committee approved the study, and the patients provided informed consent. CBCT images of 990 adult patients (aged 20-79 years) from the Stomatology Hospital (January 2018 to December 2021) were categorized based on the dental arch form and age-sex groups. Sagittal CBCT images of the maxillary central incisors were used to measure the labial and palatal bone thickness wall at 4 mm the CEJ to apical, the middle of the root, and the angle between the tooth long axis and the long axis of the alveolar process, to compare the thickness of the labial and palatal bone walls in samples of male and female patients, and to explore the relationship between the angle between the tooth long axis and the alveolar process long axis in samples of male and female patients in different age groups (20-39 years; 40-59 years; 60-79 years).@*Results@#Significant differences were found in the labiopalatine side of the alveolar bone of the maxillary incisor root position. A total of 95.8% (948/990) of the maxillary incisors were positioned more buccally, 4.1% (41/990) were positioned more midway, and 0.1% (1/990) were positioned more palatally. The thicknesses of the bone wall at the CEJ of 4 mm below the palatal side, the middle of the root, and at the apex were greater (1.82 ± 0.56 mm, 3.20 ± 1.10 mm, and 7.70 ± 2.00 mm, respectively) than those at the labial side (1.21 ± 0.32 mm, 0.89 ± 0.35 mm, and 1.86 ± 0.82 mm, respectively), with statistical significance (P<0.05). Male bone wall thickness was generally greater than female bone wall thickness (P<0.05). The angle between the long axis of male teeth and the alveolar bone was 14.77° ± 5.66°, while that of female teeth was 12.80° ± 5.70°, with a statistically significant difference (P<0.05). The angle between the long axis of teeth and the alveolar bone in the 40-59-year-old group and the 60-79-year-old group was greater than that in the 20-39-year-old group, and the difference was statistically significant (P<0.05).@*Conclusion@#A total of 95.8% of adults in South China have maxillary central incisors with root deviation toward the labial bone cortex. The thickness of the labial bone wall is much thinner than that of the labial bone wall, which is the middle of the thickness of the root. In Southern Chinese adults, the angle between the upper central incisor and the long axis of the alveolar bone in males is greater than that in females, and the degree of the angle increases with age. It is recommended to pay attention to the thickness of the bone wall around the root and the angle between the teeth before immediate implantation surgery to choose a reasonable implantation plan.

Adalimumab combined with Dexamethasone intravitreal implant in the treatment of refractory noninfectious uveitis macular edema / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the effect of adalimumab combined with dexamethasone intravitreal implant in the treatment of refractory non-infectious uveitis macular edema(UME).METHODS: A total of 92 cases(131 eyes)of refractory non-infectious UME patients admitted to our hospital from January 2020 to January 2022 were selected and randomly divided into control group, with 46 cases(63 eyes)treated with dexamethasone intravitreal implant and observation group, with 46 cases(68 eyes)treated with adalimumab subcutaneous injection combined with dexamethasone intravitreal implant. The best corrected visual acuity(BCVA), central retinal thickness(CRT), vitreous opacity and Th17/Treg cytokines were measured before and after treatment, and the occurrence of adverse reactions was recorded.RESULTS: Totally 3 cases(4 eyes)were lost to follow-up. After treatment for 1, 3, 6 and 12 mo, BCVA was improved in both groups compared with that before treatment, and CRT, vitreous opacity score, serum interleukin(IL)-17 and IL-22 levels were decreased compared with those before treatment, and serum transforming growth factor-β(TGF-β)and IL-10 levels were increased compared with those before treatment. BCVA in the observation group was better than that in the control group, and CRT, vitreous opacity score, serum IL-17 and IL-22 levels were lower than those in the control group, and serum TGF-β and IL-10 levels were higher than those in the control group(all P&#x0026;#x003C;0.05). During treatment and follow-up, no serious adverse reactions occurred in both groups.CONCLUSION: Adalimumab combined with dexamethasone intravitreal implants in the treatment of refractory non-infectious UME can significantly subside the macular edema, reduce vitreous opacity and improve visual acuity.

Application of socket-shield technique for immediate implant placement and provisionalization in esthetic zone: a case report and literature review / 口腔疾病防治

Objective@#To investigate the effect of the socket-shield technique (SST) concurrent with immediate implant placement and provisionalization (IIPP) in the aesthetic restoration of anterior teeth.@*Methods@#A case of maxillary anterior tooth stumps with a thin labial bone wall was treated with SST for preservation of labial soft and hard tissue fullness, combined with an immediate implant placement and immediate provisional crown for restoring the shape of the tooth and gingival molding@*Results@#Immediate implant placement and provisionalization restored the morphology and function of the affected tooth in the shortest possible time. The patient's labial soft and hard tissue contours in the affected tooth area were well preserved in the 18-month follow-up after the application of the SST, which presented a better aesthetic result. The literature review indicates that the indications for SST are unrestorable maxillary anterior teeth, whose dental, periodontal and periapical tissues are healthy and intact. In the esthetic zone, root shielding is effective in maintaining the soft and hard tissue contour on the labial side of the implant. However, there is no consensus on the technical details of SST, such as the ideal coronal height and thickness of the shield, and the management of the gap between the shield and the implant. Thus, more clinical studies and histologic evidence are needed to provide a reference for clinical decision-making. In addition, digital technology can improve the accuracy of implant placement and shield preparation.@*Conclusion@#The correct application of SST combined with IIPP in the esthetic zone can ensure esthetic results. However, more high-quality evidence-based medical evidence is needed for its long-term efficacy, and indications should be strictly controlled during clinical application.

Preparation of an amino hybrid mesoporous silica-based nanotopography protective coating on a titanium implant surface and evaluation of its osteogenic effect / 口腔疾病防治

Objective@#To deposit degradable amino-hybrid mesoporous silica (AHMS) in situ on the surface of titanium nanotube (TNT) and explore its protective effect on nanomorphology and osteogenesis.@*Methods@#TNT and TNT@AHMS were sequentially prepared via an anodizing method: the oil-water two-phase method (experimental group) and the acid-etched titanium method [control group (Ti)]. The parameters for synthesis were explored by changing the silicon source dosage ratio (3∶1, 1∶1, 1∶3); the surface morphology was observed by scanning electron microscope(SEM), hydrophilicity was detected by Water Contact Angle Tester, elemental composition was detected by X-ray photoelectron spectroscopy (XPS); nanoindentation test and ultrasonic oscillator were used to observe the morphological holding effect as mechanical strength of TNT@AHMS in vitro; simulated immersion experiments in vitro was used to observe the degradation behavior of the material. the MC3T3-E1 cell line was used to observe the effect of cell adhesion, proliferation and differentiation on the material; and an SD rat femoral implant model and micro-CT were used to verify the protective effect and osseointegration effect of AHMS on TNT morphology.@*Results@#The morphologies of TNT and TNT@AHMS were successfully prepared, and the silicon source ratio was 1:3. SEM showed that the titanium nanotubes were uniformly covered with AHMS coating, and the mesoporous pore size was about 4 nm. After AHMS was incorporated, the surface of the material was hydrophilic (12.78°), the presence of amino groups (NH2-) was detected, the material was completely degraded within 12 h in vitro, and the active morphology of the TNT was re-exposed with a cumulative silicon release of 10 ppm. Nanoindentation test showed that TNT@AHMS exhibited more ideal surface mechanical strength. SEM revealed that TNT maintains its own morphology under the protection of AHMS, and the TNT group suffered severe exfoliation. In addition, the early adhesion and proliferation rates, ALP activity, and bone volume fraction of cells on the TNT@AHMS surface 4 weeks after implantation were significantly higher than those in the TNT group.@*Conclusion@#By depositing AHMS on the surface of TNT, the nanotopography can be protected. It not only prevents the active base topography from exerting subsequent biological effects but also further endows the material with the ability to promote bone regeneration, laying a foundation for the future development of nanotopography-modified titanium implants.

Accuracy of digital guided implant surgery: expert consensus on nonsurgical factors and their treatments / 口腔疾病防治

@#The standardized workflow of computer-aided static guided implant surgery includes preoperative examination, data acquisition, guide design, guide fabrication and surgery. Errors may occur at each step, leading to irreversible cumulative effects and thus impacting the accuracy of implant placement. However, clinicians tend to focus on factors causing errors in surgical operations, ignoring the possibility of irreversible errors in nonstandard guided surgery. Based on the clinical practice of domestic experts and research progress at home and abroad, this paper summarizes the sources of errors in guided implant surgery from the perspectives of preoperative inspection, data collection, guide designing and manufacturing and describes strategies to resolve errors so as to gain expert consensus. Consensus recommendation: 1. Preoperative considerations: the appropriate implant guide type should be selected according to the patient's oral condition before surgery, and a retaining screw-assisted support guide should be selected if necessary. 2. Data acquisition should be standardized as much as possible, including beam CT and extraoral scanning. CBCT performed with the patient’s head fixed and with a small field of view is recommended. For patients with metal prostheses inside the mouth, a registration marker guide should be used, and the ambient temperature and light of the external oral scanner should be reasonably controlled. 3. Optimization of computer-aided design: it is recommended to select a handle-guided planting system and a closed metal sleeve and to register images by overlapping markers. Properly designing the retaining screws, extending the support structure of the guide plate and increasing the length of the guide section are methods to feasibly reduce the incidence of surgical errors. 4. Improving computer-aided production: it is also crucial to set the best printing parameters according to different printing technologies and to choose the most appropriate postprocessing procedures.

Restoration of a dental defect in a patient with ectodermal dysplasia: a case report and literature review / 口腔疾病防治

Objective@#To explore the treatment options for congenitally missing teeth in patients with ectodermal dysplasia and provide a clinical reference.@*Methods@#A patient with ectodermal dysplasia with a concave midface, anterior protrusion of the chin, and underdevelopment of the lower third of the face presented with congenital loss of multiple maxillary teeth, malocclusion of the remaining teeth, congenital loss of mandibular dentition, small dental arches, and upper and lower alveolar bone hypoplasia. The patient was treated by means of a removable partial maxillary prosthesis, implants in the anterior region of the lower mandible designed with the assistance of digital guides, and bar-clamped implant-overlay prostheses. A literature review of the protocol for the treatment of this condition was also conducted.@*Results@#In addition to good retention and stability after denture wear, an excellent occlusal relationship, improvement of the patient's facial appearance, including upper and lower lip fullness, more equal balancing of the lower and middle 1/3 of the face, and improved masticatory function were achieved. The results of the literature review showed that patients with ectodermal dysplasia who are congenitally edentulous usually have a complex intraoral situation that makes restoration difficult, and common restorative modalities for these patients include fixed bridges, removable partial dentures, complete dentures, overdentures, and implant prostheses, which need to be selected according to the actual intraoral situation of each patient. Currently, there is no consensus on the treatment of congenitally missing teeth in patients with ectodermal dysplasia, and some scholars have suggested that fixed restorations be recommended for patients with fewer missing teeth, while the option of removable or implant-covered denture restorations should be given to patients with more missing teeth, with removeable prostheses for underage patients that are replaced with permanent fixed prostheses when the jaws have stabilized.@*Conclusion@#In patients with ectodermal dysplasia with congenital tooth loss, all factors should be taken into account, and an individualized restorative plan should be developed.

Nonsuperotemporal quadrant implantation of the Ahmed glaucoma valve using modified long scleral tunnel technique for intraocular pressure control

ABSTRACT Purpose: As superotemporal implantation of the Ahmed glaucoma valve is not always feasible in cases of refractory glaucoma, this study examined the characteristics and surgical outcomes of cases in which the valve was implanted in a nonsuperotemporal quadrant using a modified long scleral tunnel technique. Methods: This retrospective case-control study included 37 eyes with nonsuperotemporal quadrant--Ahmed glaucoma valve implantation in Group 1 and 69 eyes with superotemporal Ahmed glaucoma valve implantation in Group 2. The demographic characteristics of these groups, surgical outcomes, including complications, further surgical interventions, and surgical success rates were compared. Surgical success was defined as an intraocular pressure not exceeding 21 mmHg, accompanied by a minimum reduction of 20% in intraocular pressure from the baseline without any additional intraocular pressure-lowering procedures, and the absence of light perception loss or phthisis bulbi. Results: Group 1 had significantly higher numbers of eyes with secondary glaucoma and preoperative surgical procedures than Group 2 (p<0.05). Both groups had mean preoperative intraocular pressure values, and mean intraocular pressure values at the last visit of 34.2 and 27.9 months, 35.5 ± 1.5 and 35.8 ± 1.2 mmHg, and 14.5 ± 5 and 14.9 mmHg, respectively. Although both groups had 70.2% and 75.8% as their five-year cumulative probability of success, respectively, the rates of complications, revisional surgery, and additional surgical procedures did not differ significantly (p>0.05). Conclusion: The modified long scleral tunnel technique for Ahmed glaucoma valve implantation in nonsuperotemporal quadrants achieves intraocular pressure control and complication rates comparable to superotemporal implantation.

Serum TNF-α level and probing depth as a combined indicator for peri-implant disease

Peri-implant disease (PID) is a general term for inflammatory diseases of soft and hard tissues that occur around implants, including peri-implant mucositis and peri-implantitis. Cytokines are a class of small molecule proteins, which have various functions such as regulating innate immunity, adaptive immunity, and repairing damaged tissues. In order to explore the characteristics and clinical significance of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-10, and tumor growth factor (TGF)-β1 expression levels in serum of patients with peri-implant disease, 31 patients with PID and 31 patients without PID were enrolled. The modified plaque index (mPLI), modified sulcus bleeding index (mSBI), and peri-implant probing depth (PD) were recorded. The levels of serum TNF-α, IL-6, IL-10, and TGF-β1 were detected by ELISA. TNF-α, mPLI, mSBI, and PD levels were significantly higher in the PID group. TGF-β1 levels were significantly higher in the control group. There was a significant positive correlation between TNF-α and mPLI, mSBI, and PD. TGF-β1 was negatively associated with TNF-α, mPLI, mSBI, and PD. Multiple logistic regression analysis showed that TNF-α and PD were risk factors for the severity of PID. The receiver operating curve analysis showed that high TNF-α levels (cut-off value of 140 pg/mL) and greater PD values (cut-off value of 4 mm) were good predictors of PID severity with an area under the curve of 0.922. These results indicated that TNF-α and PD can be used as a biological indicator for diagnosing the occurrence and progression of PID.

Como a judicialização da cirurgia de implante coclear impacta o Sistema Único de Saúde / How the judicialization of cochlear implant surgery impacts the Unified Health System

RESUMO Objetivo Descrever o impacto da judicialização na realização da cirurgia de implante coclear no Sistema Único de Saúde do Brasil, incluindo o serviço público e a saúde suplementar. Métodos Foi realizado um levantamento documental de acórdãos de todos os tribunais nacionais e a jurisprudência dominante, voltados à cirurgia do implante coclear no Sistema Único de Saúde, no período de 2007 a 2019, por meio da Plataforma Jusbrasil, utilizando o termo "implante coclear" para realização da busca. Também foi realizado um levantamento na plataforma DATASUS (Departamento de Informação do Sistema Único de Saúde) sobre quantos procedimentos de implante coclear unilateral e bilateral foram realizados no mesmo período. Resultados De acordo com o DATASUS, no período de 2008 a 2019 foram realizados 8.857 procedimentos de cirurgia de implante coclear pelos entes públicos ou pelas operadoras dos planos de saúde no país. Com relação à judicialização para solicitação da cirurgia do implante coclear, unilateral ou bilateral, foram encontrados 216 processos, representando 2,43% dos casos. Conclusão A judicialização da saúde, quando se considera a cirurgia do implante coclear, tem representado uma parcela mínima dos casos, o que demonstra baixo impacto no orçamento público e não tem expressiva ação na organização do Sistema Único de Saúde.

ABSTRACT Purpose To describe the impact of Judicialization on the performance of Cochlear Implant (CI) surgery in the Brazilian Unified Health System (SUS), including the public service and supplementary health. Methods A documentary survey of judgments of all National Courts and the Dominant Jurisprudence focused on CI surgery in the SUS from 2007 to 2019 was carried out through the Jusbrasil Platform using the term "cochlear implant" to carry out the search. A survey was also carried out on the DATASUS platform on how many uni and bilateral CI procedures were performed in the same period. Results According to DATASUS, from 2008 to 2019, 8,857 CI surgery procedures were performed by Public Entities or Health Plan Operators in the country. With regard to Judicialization, for requesting unilateral or bilateral CI surgery, a total of 216 processes were found, representing a total of 2.43% of Judicialization of Cochlear Implant (CI) surgery. Conclusion In view of the data, it is possible to perceive that the Judicialization of Health when we consider the CI surgery has represented a small portion of the cases, which does not demonstrate a large impact on the public budget and does not have an impact on the organization of the SUS.

Effect of different thread configurations on hydrophilic implant stability. A split-mouth RCT

Abstract This split-mouth randomized controlled trial aimed to evaluate the primary and secondary stability of hybrid implants with different thread configurations and hydrophilic surfaces. Twenty patients with a partially edentulous maxilla were selected. These patients received two types of implants with the same hydrophilic surface: CTP group: Cylindrical-Tapered implant with perforating threads; CTH: Cylindrical-Tapered implant with hybrid threads configuration (perforating and condensing threads). The primary and secondary stability parameters were measured by insertion torque and resonance frequency analysis at the time of implant placement and 7, 28, 56, and 90 days after the surgical procedure. The paired t-test was used to compare the data on the implant's stability between the groups. The statistical analysis was performed with a confidence level set at 95%. It was found that the implants in the CTH group presented higher primary stability values ​​at the time of implant placement, due to the higher ISQ (63.61 ± 9.44 vs. 40.59 ±7.46) and insertion torque (36.92 ± 16.50 Ncm vs. 28.00 ± 14.40 Ncm), than the implants in the CTP group. The CTH group presented higher ISQ values ​​in all follow-up periods: 7 days (68.67 ± 7.60 vs. 41.55 ± 9.07), 28 days (68.61 ± 5.98 vs. 47.90 ±13.10), 56 days (74.09 ± 3.96 vs. 55.85 ± 13.18), and 90 days (75.45 ± 4.02 vs. 63.47 ± 6.92) after implant placement. Hybrid implants with perforating and condensing threads demonstrated greater stability than hybrid implants with only perforating threads.

Resumo O objetivo deste estudo controlado randomizado de boca dividida foi avaliar a estabilidade primária e secundária de implantes híbridos com diferentes configurações de rosca e superfícies hidrofílicas. Vinte pacientes com maxila parcialmente edêntula foram selecionados. Esses pacientes receberam dois tipos de implantes com a mesma superfície hidrofílica: Grupo CTP: Implante cilíndrico-cônico com roscas perfurantes; Grupo CTH: Implante cilíndrico-cônico com roscas perfurantes e condensadoras. Os parâmetros de estabilidade primária e secundária foram medidos por análise de torque de inserção e frequência de ressonância no momento da colocação do implante e 7, 28, 56 e 90 dias após o procedimento cirúrgico. O teste t-pareado foi utilizado para comparação dos dados de estabilidade entre os grupos. A análise estatística foi executada levando-se em consideração um nível de confiança de 95%. Constatou-se que os implantes do grupo CTH apresentaram maiores valores de estabilidade primária no momento da colocação do implante, devido ao maior ISQ (63.61 ± 9.44 vs. 40.59 ±7.46) e torque de inserção (36.92 ± 16.50 Ncm vs. 28.00 ± 14.40 Ncm), do que os implantes do grupo CTP. Implantes do grupo CTH apresentaram valores de ISQ superiores em todos os períodos de acompanhamento: 7 dias (68.67 ± 7.60 vs. 41.55 ± 9.07), 28 dias (68.61 ± 5.98 vs. 47.90 ±13.10), 56 dias (74.09 ± 3.96 vs. 55.85 ± 13.18) e 90 dias (75.45 ± 4.02 vs. 63.47 ± 6.92). Os implantes híbridos com roscas perfurantes e condensantes demonstraram maior estabilidade do que os implantes híbridos com apenas roscas perfurantes.

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)