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.

Partial extraction therapies (PET): a review of the literature / Terapias de extração parcial (TEP): uma revisão da literatura

ABSTRACT One of the most common dental procedures is tooth extraction; however, the bone defect resulting from the process is only partially restored, leading to considerable bone loss. To rehabilitate a fully or partially edentulous patient, we must handle these sites with delicate surgical procedures. There is a large literature presenting attempts to overcome the negative effects of a dental extraction, with the aim of reducing tissue volume loss or restoring the alveolar architecture. In this context, Partial Extraction Therapy (PET) represents a subgroup of interventions to prevent bone loss after extraction using the tooth itself to prevent alveolar bone loss. This literature review aims to make a survey of the published articles on PET, with an emphasis on socket shield technique, and to explain the other techniques such as root burial, pontic-shield and proximal socket-shield, their indications and counter indications in order to deepen the knowledge of these techniques. To identify the included or considered studies, we adopted a detailed search strategy for MEDLINE and Cochrane Library focused in the last 31 years, whose language was English, Spanish or Portuguese. This text presents an analysis of current data regarding the alternatives for alveolar preservation and the installation of immediate implants in these areas, presenting the possibility of a different surgical technique. However, due to the immaturity and lack of conclusive scientific evidence regarding the predictability of the procedures, it is considered that the use of the socket shield technique must be done in an extremely cautious way.

RESUMO Um dos procedimentos odontológicos mais comuns é a extração dentária, contudo, , o defeito ósseo decorrente do processo é apenas parcialmente restaurado, levando a uma perda ossea volumétrica consideravel. Para reabilitar um paciente totalmente ou parcialmente desdentado, devemos manusear estes sitios com intervenções cirúrgicas delicadas. Há uma vasta literatura apresentando tentativas de transpor os efeitos negativos de uma extração dentária, com o objetivo de diminuir a perda volumétrica tecidual ou restaurar a arquitetura alveolar. Neste contexto, a Terapia de Extração Parcial (TEP) representa um subgrupo de intervenções para prevenir a perda óssea após exodontia, usando o próprio dente para prevenir a perda óssea alveolar. Essa revisão de literatura tem por objetivo fazer um levantamento dos artigos publicados sobre as TEP, com ênfase na técnica de socket shield, e explanar a cerca das demais técnicas como sepultamento radicular, pontic-shield e proximal socket-shield, suas indicações e contra-indicações, a fim de aprofundar o conhecimento dessas técnicas. Para a identificação dos estudos inclui?dos ou considerados, adotamos a estrate?gia de busca detalhada para os bancos MEDLINE e Biblioteca Cochrane nos u?ltimos 31 anos, cujo idioma fosse o ingle?s, espanhol ou o portugue?s. Este texto, apresenta uma análise de dados atuais a respeito das alternativas para a preservação alveolar e instalação de implantes imediatos nestas áreas, apresentando a possibilidade de uma técnica cirúrgica diferenciada. No entanto, devido a imaturidade e falta de comprovação cientifica contundente a respeito da previsibilidade dos procedimentos, considera-se que o emprego da técnica de socket shield deve ser feito de forma cautelosa.

Neo-osteogenesis using an intentionally exposed polypropylene membrane after tooth extraction versus guided bone regeneration technique: a single-blind randomized controlled trial / Neo-osteogénesis utilizando una membrana de polipropileno expuesta intencionalmente después de la extracción del diente versus técnica de regeneración ósea guiada: ensayo clínico aleatorizado ciego / Neo-osteogênese utilizando uma membrana de polipropileno exposta intencionalmente após extração dentária versus técnica de regeneração óssea guiada: ensaio clínico randomizado e cego

Introduction: The intentionally exposed polypropylene (PP) membrane has been proposed for guided bone regeneration (GBR) of the alveo lar bone after extraction; however, there are biological limitations to this proposal. This study aimed to describe the effects of the PP membrane on neo-osteogenesis after tooth extraction, comparing to intentionally ex posed and primary soft tissue coverage techniques. Methodology: This clinical trial followed the TIDieR checklist and guide. Clinical and histo logical parameters of alveolar repair were compared between groups: 1 (control group), without regenerative procedure; 2, GBR; and 3, inten tionally exposed membrane. Results: Group 3 showed slight effect on the quality of new bone, compared to the control group. Although the GBR was underestimated by the early exposure of the membrane, alveo lar repair and newly formed bone were superior to the other groups. Poly propylene membrane intentionally exposed compromised the volume density of the immature and mineralized bone matrix, the osteoblast and osteocyte count, and stimulated the granulation tissue formation and local inflammatory infiltrate. Conclusions: Despite the exposure of the PP membrane in GBR, this technique improved the quality of new bone and alveolar repair compared to the surgical technique of intentional exposure and alveolus only sutured.

RESUMEN Introducción: La membrana de polipropileno (PP) intencionalmente expuesta ha sido propuesta para la regeneración ósea guiada (GBR) del hueso alveolar después de la extracción; sin embargo, existen limitaciones biológicas a esta propuesta. Este estudio tuvo como objetivo describir los efectos de la membrana de PP en la neo-osteogénesis después de la extracción del diente, en comparación con las técnicas de cobertura de tejido blando primarias y expuestas intencionalmente. Metodología: Este ensayo clínico siguió la lista de verificación y la guía TIDieR. Se compararon los parámetros clínicos e histológicos de la reparación alveolar entre los grupos: 1 (grupo control), sin procedimiento regenerativo; 2, GBR; y 3, membrana expuesta intencionalmente. Resultados: el grupo 3 mostró un ligero efecto sobre la calidad del hueso nuevo, en comparación con el grupo de control. Aunque la GBR fue subestimada por la exposición temprana de la membrana, la reparación alveolar y el hueso neoformado fueron superiores a los otros grupos. La membrana de polipropileno expuesta intencionalmente comprometió la densidad de volumen de la matriz ósea inmadura y mineralizada, el recuento de osteoblastos y osteocitos, y estimuló la formación de tejido de granulación y el infiltrado inflamatorio local. Conclusiones: A pesar de la exposición de la membrana de PP en GBR, esta técnica mejoró la calidad del hueso nuevo y la reparación alveolar en comparación con la técnica quirúrgica de exposición intencional y alvéolo solo suturado.

Introdução: A membrana de polipropileno (PP) intencionalmente exposta tem sido proposta para regeneração óssea guiada (ROG) do osso alveolar após exodontia; no entanto, existem limitações biológicas a esta proposta. Este estudo teve como objetivo descrever os efeitos da membrana de PP na neo-osteogênese após a extração dentária, comparando com as técnicas de exposição intencional e cobertura primária de tecidos moles. Metodologia: Este ensaio clínico seguiu a lista de verificação e o guia TIDieR. Parâmetros clínicos e histológicos do reparo alveolar foram comparados entre os grupos: 1 (grupo controle), sem procedimento regenerativo; 2, GBR; e 3, membrana intencionalmente exposta. Resultados: O Grupo 3 apresentou leve efeito na qualidade do novo osso, em comparação com o grupo controle. Embora o GBR tenha sido subestimado pela exposição precoce da membrana, o reparo alveolar e o osso neoformado foram superiores aos outros grupos. A exposição intencional da membrana de polipropileno comprometeu a densidade volumétrica da matriz óssea imatura e mineralizada, a contagem de osteoblastos e osteócitos e estimulou a formação de tecido de granulação e infiltrado inflamatório local. Conclusões: Apesar da exposição da membrana PP na ROG, esta técnica melhorou a qualidade do novo osso e da reparação alveolar em comparação com a técnica cirúrgica de exposição intencional e alvéolo apenas suturado.

La alveolitis y sus factores de riesgo en la población adulta joven / Dry socket and its risk factors in a young adult population

Introducción: La alveolitis es la complicación más frecuente de la extracción dental, y constituye la causa más común de las consultas de Urgencias, pues los pacientes presentan dolor en el período postoperatorio. Aunque la etiología de esta afección no es muy conocida, se considera que es un trastorno multifactorial. Objetivos: Determinar el tipo de alveolitis más frecuente en la muestra objeto de estudio, así como establecer la relación entre los factores de riesgo y el tipo de alveolitis. Métodos: Se realizó un estudio descriptivo y trasversal en el Servicio de Urgencias de la Clínica Estomatológica «Celia Sánchez Manduley», de Santa Clara, Villa Clara, desde febrero de 2020 a junio de 2021. El estudio se realizó en un total de 51 pacientes diagnosticados con alveolitis dental. Se estudiaron las siguientes variables: tipo de alveolitis y factores de riesgo (edad, sexo, antecedentes de enfermedades, el uso de tabletas anticonceptivas, hábitos tóxicos, condiciones del medio bucal, características de la maniobra quirúrgica y cuidados postoperatorios); los datos fueron recogidos en un formulario. Resultados: Predominó la alveolitis seca en las pacientes del sexo femenino. El hábito de fumar y la práctica de una maniobra quirúrgica compleja fueron los factores de riesgo preponderantes. Conclusiones: Existe una relación significativa entre la presencia de alveolitis seca y las pacientes del sexo femenino asociadas a los hábitos tóxicos, el uso de tabletas anticonceptivas, y haber sido sometidas a una maniobra quirúrgica compleja.

Introduction: dry socket is the most frequent complication after a dental extraction and constitutes the most common cause of emergency consultations, since patients have pain in the postoperative period. It is considered to be a multifactorial disorder although the etiology of this condition is not well known. Objectives: to determine the most common type of dry socket in the sample under study, as well as to establish the relationship between risk factors and the type of dry socket. Methods: a descriptive and cross-sectional study was carried out in the emergency department at "Celia Sánchez Manduley" Dental Clinic, in Santa Clara, Villa Clara, from February 2020 to June 2021. The study was carried out in a total of 51 patients who were diagnosed with dry socket. Type of dry socket and risk factors such as age, gender, history of diseases, use of contraceptive tablets, toxic habits, conditions of the oral environment, characteristics of the surgical procedure and postoperative care were the variables studied; the data was collected in a form. Results: dry socket predominated in female patients. Smoking and performing a complex surgical maneuver were the predominant risk factors. Conclusions: there is a significant relationship among the presence of dry socket and female patients associated with toxic habits, the use of contraceptive tablets, and having undergone a complex surgical maneuver.

Prevalencia de alveolitis seca asociada a urgencias dolorosas durante el aislamiento social preventivo y obligatorio de la pandemia COVID-19 en un servicio de urgencias del área bonaerense metropolitana en la República ArgentinaPrevalence of dry socket associated with urgent dental extractions due to pain performed at an emergency service in the Buenos Aires Metropolitan Area during the mandatory preventive social isolation for the COVID-19 pandemic in Argentina / Prevalence of dry socket associated with urgent dental extractions due to pain performed at an emergency service in the Buenos Aires Metropolitan Area during the mandatory preventive social isolation for the COVID-19 pandemic in Argentina

Objective: To evaluate the prevalence of dry socket as a postoperative complication in cases where there was intense local pain in the preoperative state, during the preventive mandatory social isolation (PMSI) for the COVID-19 pandemic in Argentina. Methods: This was a descriptive study, which included 1209 walk-in patients at the emergency and orientational service at Buenos Aires University School of Dentistry during the PMSI from March 20 to June 20, 2020, with indication for dental extraction as well as intense acute pain at the surgical site. The presence of dry socket was exploratoryly associated with the variables age, sex, smoking and chronic medication use. Results: 1209 patients were operated, resulting in a total 1372 dental extractions. Average patient age was 41 years. The prevalence found in this study was 1.06%. Conclusion: The prevalence of dry socket was 1%, not being higher than other experiences where pain was not considered a condition prior to extraction.

Objetivo: Evaluar la prevalencia de alveolitis seca como complicación postquirúrgica, cuando existió dolor intenso local en el preoperatorio, durante el Aislamiento Social Preventivo y Obligatorios (ASPO) de la pandemia COVID-19 en la República Argentina. Material y Métodos: Se realizó un estudio descriptivo en el que fueron incluidos 1209 pacientes, que presentaron indicación de exodoncia y concurrieron al servicio de urgencias y orientación de pacientes de la Facultad de Odontología de la universidad de Buenos Aires, durante el ASPO en un periodo comprendido entre el 20 de marzo y el 20 de junio de 2020, con dolor agudo e intenso en el sitio quirúrgico. La presencia de alveolitis seca fue asociada de forma exploratoria con las variables edad, sexo, tabaquiamo y medicación de uso crónico. Resultados: Fueron operados 1209 pacientes a los que se les realizaron un total de 1372 exodoncias, con un promedio de edad 41 años. La prevalencia fue de 1,06%. Conclusión: La prevalencia de alveolitis seca fue del 1%, no siendo superior a otras experiencias donde no se consideró al dolor como una condición previa a la exodoncia.

Research progress in the design of surgical flaps for impacted mandibular third molars / 中国基层医药

The incidence of impacted mandibular third molars is high. Many complications occur after extraction of impacted third molars, such as bleeding, pain, swelling, and dry grooves, which affect quality of life. To reduce postoperative complications, various skin flap designs have emerged with time. This paper summarizes the current research progress in designing impacted mandibular third molar flaps, providing a reference for clinical work.

Biomechanical Effects of Jumping Distance on Stress Distributions of Anterior Dental Implant with Socket-Shield Technique / 医用生物力学

Objective To study the biomechanical effect of jumping distance on dental implants with socket-shield technique (SST), so as to provide references for clinical standards of jump distance. Methods Based on clinical characteristics, four groups of three-dimensional (3D) SST implant system models with 0, 0. 5, 1 and 1. 5 mm jumping distance were established, and the corresponding material parameters were assigned. The peak stress and stress distributions on models were simulated under specific occlusal condition. Results When the jumpingdistance was non-zero, namely, the implant was not in contact with the retained root fragment, the stress of the implant and abutment increased with the increase of jumping distance, and the peak stress in root fragment and periodontal membrane decreased with the increase of jumping distance. When the jumping distance was zero, the peak stress of the implant, abutment, root fragment and periodontal membrane reached the maximum, far exceeding that of the other groups. Conclusions The jumping distance has a significant effect on the SST implant system. It is recommended to take a larger jumping distance in clinical practices. The edge of the root fragment should be rounded, and the size of the lower edge should not be too small.

Histopathological evaluation of the effect of Salvadoria persica and Nigella sativa on the healing of tooth extraction socket in animal

To assess the effects of Salvadoria persica and Nigella sativa combination in tooth socket healing after extraction that can be a novel remedy for tooth extraction socket. Methods: Forty rabbits were included in this study, divided into two groups (control and experimental) with 20 rabbits. Upper right central incisors were extracted for all animals, the tooth sockets of the experimental group were dressed using an admix of Salvadoria persica and Nigella sativa immediately after irrigation with normal saline. In contrast, the extraction sockets of the control group were left without dressing. Biopsies were taken after euthanizing the animals at 1, 3, 7, and 14 days after treatment, histological examination was done for the samples at the given periods respectively. Results: On day 1 post-treatment, histological examination of the experimental group sections showed less acute inflammatory reaction than the control group. This continued to be reduced until the seventh day. The amount of granulation tissue formation was more in the experimental group along the different periods of the study, while new bone formation was observed after 1 week as woven bone, increased after 2 weeks and appeared as woven and lamellar bone in both experimental and control groups. Conclusions: A mixture of Salvadoria persica and Nigella sativa has an anti-inflammatory effect and accelerate bone healing by stimulating bone formation in the tooth extraction socket

The effect of scaffold hydroxyapatite derived from portunus pelagicus shell on the expression of fibroblast growth factor-2 (fgf-2) and bone morphogenetic proteins-2 (bmp -2) in the extraction sockets of cavia cobaya / El efecto del scaffold de hidroxiapatita derivada de portunus pelagicus sobre la expresión del factor de crecimiento de fibroblastos-2 (FGF-2) y las proteínas morfogenéticas óseas-2 (BMP-2) en los alvéolos dentarios de cavia cobaya

Objetive: To determine the expression of Fibroblast Growth Factor (FGF)-2 and Bone Morphogenetic Protein (BMP)-2 after application of scaffold hydroxyapatite from Rajungan crab shell (Portunus pelagicus) in the tooth extraction socket of Cavia cobaya. Material and Methods: This study used a post-test only control group design with 28 Cavia cobaya separated into two groups, control and treatment group. The left mandibular incisor was extracted, and socket preservation was conducted. A hydroxyapatite graft derived from crab shells was mixed with gelatin and eventually turned into a scaffold, which was afterward put into the extraction socket. After 7 days and 14 days, each group was terminated and examined using immunohistochemical staining to observe the expression of FGF-2 and BMP-2. One-Way Anova and Tukey HSD were used to examine the research data. Results: FGF-2 and BMP-2 expressions were observed higher in the group that received hydroxyapatite scaffold at the post-extraction socket than those in the group that did not receive hydroxyapatite scaffold. Conclusion: The application of a hydroxyapatite scaffold from Rajungan crab shell (Portunus pelagicus) to the tooth extraction socket can increase FGF-2 and BMP-2 expression.

Objetivo: Determinar la expresión del factor de crecimiento de fibroblastos (FGF)-2 y la proteína morfogenética ósea (BMP)-2 después de la aplicación de hidroxiapatita de andamio de caparazón de cangrejo Rajungan (Portunus pelagicus) en el alvéolo de extracción dental de Cavia cobaya. Material y Métodos: Este estudio utilizó un diseño de grupo de control solo posterior a la prueba con 28 Cavia cobaya separados en dos grupos, grupo de control y grupo de tratamiento. Se extrajo el incisivo mandibular izquierdo y se realizó la preservación del alvéolo. Un injerto de hidroxiapatita derivado de caparazones de cangrejo se mezcló con gelatina y se convirtió en un andamio, que luego se colocó en el alvéolo de extracción. Después de 7 días y 14 días, se terminó cada grupo y se examinó mediante tinción inmunohistoquímica para observar la expresión de FGF-2 y BMP-2. Se utilizaron One-Way Anova y Tukey HSD para examinar los datos de la investigación. Resultados: Las expresiones de FGF-2 y BMP-2 se observaron más altas en el grupo que recibió la estructura de hidroxiapatita en el alvéolo posterior a la extracción que en el grupo que no recibió la estructura de hidroxiapatita. Conclusión: La aplicación de un andamio de hidroxiapatita de caparazón de cangrejo Rajungan (Portunus pelagicus) al alvéolo de extracción dental puede aumentar la expresión de FGF-2 y BMP-2.

Infección de cavidad anoftálmica por Scedosporium sp. en paciente inmunocompetente: Reporte de caso / Anophthalmic socket infection caused by Scedosporium sp. in immunocompetent patient: Case Report

Resumen Scedosporium sp. es un género de hongos filamentosos que de forma infrecuente se relaciona a infecciones localizadas o diseminadas en pacientes inmunocom prometidos, o inmunocompetentes con trauma penetrante contaminado. Reportamos el caso de un paciente masculino de 31 años con antecedente de trauma penetrante por arma de fuego requiriendo enucleación de su ojo izquierdo, quien 12 años posterior al trauma inicial presenta necrosis de la cavidad anoftálmica con extrusión del implante y lisis del párpado inferior, finalmente identificando Scedosporium sp. como germen causal, y un mucocele en el seno frontal como reservorio. El paciente recibió tratamiento médico con voriconazol sistémico, desbridamiento quirúrgico amplio, y resección endoscópica del quiste de retención mucoso, con una evolución satisfactoria. Las infecciones micóticas de la cavidad anoftálmica son infrecuentes, requiriendo una alta sospecha diagnóstica y trata miento agresivo para evitar consecuencias potencialmente devastadoras.

Abstract Scedosporium sp. is a genus of filamentous fungi that is infrequently related to localized or disseminated infections in either immunocompromised patients, or immunocompetent patients with penetrating contaminated trauma. We report the case of a 31-year-old patient with a history of penetrating gunshot wound that required enucleation of his left eye, who 12 years after initial trauma presents necrosis of the anophthalmic socket with implant extrusion and lysis of inferior eyelid, finally identifying the causal agent to be Scedosporium sp. The patient received medical treatment with systemic voriconazole, and wide surgical debridement, with a satisfactory evolution. Fungal infections of anophthalmic sockets are infrequent, requiring a high diagnostic suspicion and aggressive treatment to avoid potentially devastating consequences.

Evidencia clínica e histológica de regeneración de tejido blando a partir de una matriz colágena porcina. Reporte de Caso

RESUMEN: La pérdida de un diente resulta en la pérdida de volumen de tejidos duros y blandos lo que dificulta lograr resultados estéticamente satisfactorios. Con el fin de disminuir la morbilidad que provoca un injerto autólogo en el sellado del alveolo se puede reemplazar por una matriz reabsorbible de colágeno. El presente reporte de caso evaluó clínica e histológicamente una matriz colágena de porcino, en la regeneración de tejido blando, durante la instalación de un implante inmediato a una extracción dentaria. A los 6 meses clínicamente se obtuvo un tejido con una apariencia estética final óptima e histológicamente se evidenció la formación de un tejido epitelial y conjuntivo compatible con la de una mucosa normal.

ABSTRACT: Tooth loss results in loss of hard and soft tissue volume, making it difficult to achieve aesthetically pleasing results. In order to decrease the morbidity caused by an autologous graft in the alveolus seal, it can be replaced by a resorbable matrix of collagen. The present case report evaluated clinically and histologically a porcine collagen matrix, in soft tissue regeneration, during the installation of an implant immediately after dental extraction. At 6 months, clinically, a tissue with an optimal final aesthetic appearance was obtained and histologically, the formation of an epithelial and connective tissue compatible with that of a normal mucosa was evidenced.

Assessment of Incidence and Risk Factors of Dry Socket

Background: Alveolar osteitis (AO) is one of the extractions wound healing disorder. Most authors agree that surgical trauma and difficulty of surgery play a significant role in the development of AO. Hence, under the light of above - mentioned data, the present study was undertaken for assessing the incidence and risk factors of dry socket. Methods: A total of 200 subjects scheduled to undergo dental extraction procedures under local anesthesia were included in the p resent study. Complete demographic and clinical details of all the patients were obtained. All the procedures were carried out under the hands of experienced surgeons. Follow - up was done and incidence of dry socket was recorded. Results: Overall, incidenc e of dry socket in the present study was 17.5 percent. Positive tobacco smoking/chewing habit, Oral contraceptives, Female gender, Existing tooth/gum infection, Past history of dry socket, Traumatic extraction and Mandibular molar extraction were the risk factors in 62.85 %, 34.28 %, 71.42 %, 14.28 %, 25.71 %, 42.85 % and 54.28 % of the patients. Conclusion: Dry socket is a commonly encountered phenomenon and can occur the under the hands of skilled and experienced oral surgeons also. Hence, early recogniti on is necessary.

Alveolar Ridge Preservation after Tooth Extraction and Replacement with Fibre reinforced Composite Bridge in a Young Patient: A Case Report

ABSTRACT@#Alveolar ridge preservation is a surgical procedure aimed to preserve the alveolar bone after tooth extraction to eliminate or reduce the need for bone augmentation during implant placement. It includes the use of membrane that is either being used alone or in combination with a bone replacement graft. This case report describes the technique of alveolar ridge preservation after tooth extraction using a xenogenic bone graft combined with a resorbable collagen membrane, and the fabrication of an anterior fibre-reinforced composite (FRC) bridge in an 18-year-old male patient. This treatment allows him to have a good preservation of the volume and architecture of the alveolar ridge as well as soft tissues and temporarily replace a missing anterior tooth until a definitive restoration can be achieved.

The Evaluation of Bone Regeneration Following Socket Preservation with Concentrated Growth Factor (CGF) and Poly Lactic-Co-Glycolic Acid (PLGA) Scaffold in Rabbits

ABSTRACT@#Various grafting materials are utilised to facilitate regeneration. There is currently a paradigm shift towards applying poly lactic-co-glycolic acid (PLGA), which is regarded as an excellent scaffold for tissue engineering. Concentrated growth factor (CGF) has also been reported to promote wound healing. Nevertheless, the role of PLGA microspheres as a substitute for bone graft material with CGF in bone regeneration remains unclear. This study was designed to evaluate the effect of CGF with PLGA on bone formation and the expression of alkaline phosphatase (ALP) following socket preservation. PLGA microspheres were prepared using double solvent evaporation method and observed under scanning electron microscopy (SEM). A 6 mL of rabbit’s blood was collected from the marginal ear vein and centrifuged to obtain CGF. Blood was also collected for ALP assessment from 24 New Zealand White (NZW) male rabbits subjected to the first upper left premolar extraction. Sockets were filled with CGF, PLGA, CGF+PLGA or left empty and observed with microscopic computed tomography (micro-CT) at four weeks and eight weeks. The SEM image revealed a spherical shape with interconnected pores on the surface of the PLGA particles. Repeated measures ANOVA were used to evaluate the effect of time and treatment (p < 0.05) with significant differences in bone width, height, volume, volume fraction and expression of ALP was observed with CGF+PLGA. Both CGF and PLGA have the potential as the alternative grafting materials and this study could serve as an ideal benchmark for future investigations on the role of CGF+PLGA in bone regeneration enhancement.

Application of digital design combined with 3D-printing technologies in dental autotransplantation / 口腔疾病防治

Objective@#To evaluate the therapeutic effect of dental autotransplantation with the application of digital design combined with 3D printing of donor tooth models and recipient alveolar fossa model preoperatively.@*Methods@# Twelve cases that could not be retained due to tooth fracture or extensive absorption of alveolar bone were recruited in the study. Cone-beam computed tomography (CBCT) data were imported into Mimics software for digital design, and the best-matched third molar was selected as the donor tooth. Replicas of the donor teeth and the recipient socket were printed out with three-dimensional (3D) printing technologies as a simulation model for recipient tooth socket preparation. During tooth autotransplantation, preparation of the recipient tooth socket and the donor tooth were guided by the 3D-printed replicas sequentially. Then, the donor tooth was implanted into the recipient tooth pocket. Patients were followed up at 3, 6 and 12 months after the operation, with CBCT examination to evaluate the status of bone reconstruction and periodontal ligaments at each time point. @*Results@#Twelve patients were transplanted with an autogenous third molar with the apical foramen completely closed. Among them, 7 patients had alveolar fossa infection before the operation, of which 1 had extensive resorption of the alveolar bone due to the infection. All 12 patients recovered well after the operation and were followed up for at least 12 months. In total, 11 caseswere successful in tooth autotransplantation with normal mastication, and 1 case had root resorption 14 months postoperation.@*Conclusion@#Digital design combined with 3D printing technology can assistin the selection of thebest-matched donor tooth and preparation of the recipient socket before tooth transplantation proceduresand reduce the extra-alveolar exposure time of the donor tooth and number of trial placementsintothe alveolar fossa. Thus, this combined strategy can effectively improve the outcome of dental autotransplantation.

Increased Expression of RUNX2 and ALP Resulting from a Combination of Propolis Extract and Bovine Bone Graft in Socket Preservation Material

Abstract The aim of this study was to determine the inductive effect of a combination of propolis and BBG extract on RUNX2 and ALP expression in the tooth extraction sockets of Cavia cobaya. Fifty- six Cavia cobaya were divided into four groups: polyethylene glycol (PEG), propolis extract + PEG, BBG + PEG, and propolis extract + BBG + PEG. The lower left incisor was extracted, and the socket subsequently filled with material according to the specific group of which the subject was a member. The subjects were sacrificed on the 14th and 30th days. Immunohistochemical staining was carried out under a light microscope at 400x magnification. Statistical analysis was then carried out by means of One-Way ANOVA and Tukey HSD tests. The mean number of RUNX2 and ALP expressions in each group was significantly different. The highest number of RUNX2 and ALP expressions occurred in the propolis + BBG + PEG group on the 30th day, while the lowest expressions were observed in the control group on the 14th day. A combination of propolis and BBG extract at a concentration of 2% of active substance effectively increases the expression of RUNX2 and ALP in preserving the tooth extraction sockets of Cavia cobaya.

A single session of antimicrobial photodynamic therapy does not influence the alveolar repair process in rats

Abstract: The aim of this study was to use microscopic and molecular techniques to evaluate the effects of a single session of antimicrobial photodynamic therapy (aPDT) on the alveolar repair process after tooth extraction in rats. The study sample included 84 rats divided into four groups, as follows: a) Control - untreated socket; b) Laser - socket treated using photobiomodulation; c) TBO - socket treated with topic application of the photosensitizer agent, toluidine blue O (TBO); and d) aPDT - socket treated with TBO and laser irradiation. An additional rat was used for thermal mapping during socket irradiation. The animals were euthanatized at 6, 15, and 28 days after unilateral extraction of the upper incisor. Quantitative and qualitative analyses of the connective and bone tissues, blood clot, blood vessel, and inflammatory infiltrate were performed, and real-time polymerase chain reaction was used to study the expression of genes (collagen type I, osteocalcin, alkaline phosphatase [ALP], runt-related transcription factor 2 [RUNX2], and vascular endothelial growth factor [VEGF]) involved in the bone healing process. No statistically significant differences in microscopic and molecular outcomes were observed between the groups (p > 0.05). A positive correlation was seen to exist between blood clot and VEGF (p = 0.000), and a negative correlation was observed between bone tissue and ALP (p = 0.028) and blood vessel and VEGF (p = 0.018). A single session of aPDT in the dental extraction site did not influence the alveolar repair process in rats.

Characterizations of alveolar repair after mandibular second molar extraction: an experimental study in rats

Abstract Characterizations of rat mandibular second molar extraction socket with significantly different buccal and lingual alveolar ridge width remain unclear. Objective: To observe alterations in the alveolar ridge after extraction of mandibular second molars, and to examine processes of alveolar socket healing in an experimental model of alveolar ridge absorption and preservation. Methodology: Eighteen Wistar rats were included and divided into six groups regarding healing time in the study. Bilateral mandibular second molars were extracted. The rats with tooth extraction sockets took 0, 1.5, 2, 3, 4 and 8 weeks of healing. Histological observation, tartrate-resistant acidic phosphatase (TRAP) staining, Masson's trichrome staining, immunohistochemical staining and micro-computed tomography (micro-CT) were applied to estimate alterations in the alveolar ridge. Results: Different buccal and lingual alveolar ridge width led to different height loss. Lingual wall height (LH) decreased significantly two weeks after tooth extraction. Buccal wall height rarely reduced its higher ridge width. From two to eight weeks after extraction, bone volume (BV/TV), density (BMD), and trabecular thickness (Tb.Th) progressively increased in the alveolar socket, which gradually decreased in Tb.Sp and Tb.N. LH showed no significant change during the same period. Osteogenic marker OCN and OPN increased during bone repair from two to eight weeks. The reduced height of the lingual wall of the tooth extraction socket was rarely repaired in the later repair stage. Osteoclast activity led to absorption of the alveolar ridge of the alveolar bone wall within two weeks after operation. We observed positive expression of EMMPRIN and MMP-9 in osteoclasts that participated in the absorption of the spire region. Conclusion: Extraction of rat mandibular second molars may help the study of alveolar ridge absorption and preservation. The EMMPRIN-MMP-9 pathway may be a candidate for further study on attenuating bone resorption after tooth extraction.

Cone-beam computed tomographic evaluation of dimensional hard tissue changes following alveolar ridge preservation with leucocyte and platelet-rich fibrin techniques: a pilot study / Avaliação tomográfica computadorizada de feixe cônico das alterações dimensionais de tecido duro após preservação de crista alveolar com técnicas de fibrina rica em leucócitos e plaquetas: um estudo piloto

Objective: This study evaluated the effect of leucocyte and platelet-rich fibrin (L-PRF) techniques used in alveolar ridge preservation on dimensional hard tissue changes of the alveolar ridge assessed using cone-beam computed tomography (CBCT) scans. Material and Methods: Elective alveolar ridge preservation surgeries were performed on seven systemically healthy patients who underwent single posterior tooth extraction. Patients were randomly treated with PRF mixed with a commercial bone xenograft (n = 3) or PRF plug (n = 4). CBCT scans were taken immediately after tooth extraction and then four months later, just before implant surgery. Dimensional alterations in socket height (SH), socket area (SA) and socket volume (SV) were evaluated on CBCT scans by percentage differences before and after treatments. Results: Sockets treated with PRF plus bone xenograft had a tendency to maintain alveolar bone dimensions over time (SH= 11.22% to 82.74%, SA= 1.84% to 48.91% and SV= 9.11% to 203.62%), while sockets treated only with PRF plug technique presented only a modest increase in height (SH= 1.47% to 11.11%) but greater alveolar ridge resorption confirmed by a decrease in socket area and volume dimensions (SA= 0.21% to -24.09% SV= 8.53% to -54.12%). Conclusion: Within the limitations of this study, the maintenance of alveolar socket dimensions was observed when PRF was associated with a xenograft. However, the loss of alveolar ridge dimensions was not entirely prevented by PRF treatment alone.(AU)

Objetivo: Este estudo avaliou o efeito das técnicas de fibrina rica em leucócitos e plaquetas (L-PRF) usadas na preservação da crista alveolar em alterações dimensionais de tecido duro da crista alveolar avaliadas por tomografia computadorizada de feixe cônico (CBCT). Material e Métodos: Foram realizadas cirurgias eletivas de preservação da crista alveolar em sete pacientes sistemicamente saudáveis que foram submetidos a uma única extração dentária posterior. Os doentes foram tratados aleatoriamente com PRF misturado com um xenoenxerto ósseo comercial (n = 3) ou com PRF plug (n = 4). CBCT foi realizada imediatamente após a extração dentária e quatro meses depois, imediatamente antes da cirurgia de implante. Alterações dimensionais na altura do alvéolo (SH), área do alvéolo (SA) e volume do alvéolo (SV) foram avaliadas em exames CBCT por diferenças percentuais antes e depois dos tratamentos. Resultados: Os alvéolos tratados com PRF mais xenoenxerto ósseo apresentaram tendência a manter as dimensões ósseas alveolares ao longo do tempo (SH= 11.22% a 82.74%, SA= 1.84% a 48.91% e SV= 9.11% a 203.62%), enquanto alvéolos tratados apenas com a técnica de PRF plug apresentaram apenas um aumento modesto na altura (SH= 1.47% a 11.11%), mas uma maior reabsorção alveolar confirmada pela redução das dimensões de área e volume do alvéolo (SA= 0.21% a -24.09% SV= 8.53% a -54.12%). Conclusão: Dentro das limitações deste estudo, a manutenção das dimensões alveolares foi observada quando o PRF foi associado ao xenoenxerto. No entanto, a perda das dimensões alveolares não foi totalmente evitada pelo tratamento apenas com PRF. (AU)

"Cirugía guiada de implantes inmediatos, utilizando la técnica Socket Shield"

RESUMEN: Este informe clínico describe el tratamiento rehabilitador realizado a un paciente con fracturas horizontales de ambos incisivos centrales superiores, mediante la colocación de implantes inmediatos, utilizando una guía quirúrgica y la técnica Socket Shield. Después de un año de seguimiento, no se observan alteraciones clínicas de los tejidos duros y blandos, manteniéndose una alta estética. La cirugía guiada junto a la técnica Socket Shield es un enfoque de tratamiento prometedor para la rehabilitación con implantes de la zona anterior.

ABSTRACT: This clinical report describes the restorative treatment performed on a patient with horizontal fractures on both upper central incisors, by placing immediate implants using both surgical guide and the Socket Shield technique. After one year of monitoring, no clinical hard or soft tissues alterations were observed, maintaining high aesthetics. Guided surgery together with Socket Shield technique is a promising treatment approach for anterior implant rehabilitation.