Micro-Computed Tomography Analysis of Peri-Implant Bone Defects Exposed to a Peri-Implantitis Microcosm, with and without Bone Substitute, in a Rabbit Model: A Pilot Study.

Peri-implantitis is an inflammatory condition characterized by inflammation in the peri-implant connective tissue and a progressive loss of supporting bone; it is commonly associated with the presence of biofilms on the surface of the implant, which is an important factor in the development and progression of the disease. The objective of this study was to evaluate, using micro-CT, the bone regeneration of surgically created peri-implant defects exposed to a microcosm of peri-implantitis. Twenty-three adult New Zealand white rabbits were included in the study. Bone defects of 7 mm diameter were created in both tibiae, and a cap-shaped titanium device was placed in the center, counter-implanted with a peri-implantitis microcosm. The bone defects received a bone substitute and/or a resorbable synthetic PLGA membrane, according to random distribution. Euthanasia was performed 15 and 30 days postoperatively. Micro-CT was performed on all samples to quantify bone regeneration parameters. Bone regeneration of critical defects occurred in all experimental groups, with a significantly greater increase in cases that received bone graft treatment (p < 0.0001), in all measured parameters, at 15 and 30 days. No significant differences were observed in the different bone neoformation parameters between the groups that did not receive bone grafts (p > 0.05). In this experimental model, the presence of peri-implantitis microcosms was not a determining factor in the bone volume parameter, both in the groups that received regenerative treatment and in those that did not.

Poly-3-hydroxybutyrate-silver nanoparticles membranes as advanced antibiofilm strategies for combatting peri-implantitis.

Dental implant success is threatened by peri-implantitis, an inflammation leading to implant failure. Conventional treatments struggle with the intricate microbial and host factors involved. Antibacterial membranes, acting as barriers and delivering antimicrobials, may offer a promising solution. Thus, this study highlights the potential of developing antibacterial membranes of poly-3-hydroxybutyrate and silver nanoparticles (Ag Nps) to address peri-implantitis challenges, discussing design and efficacy against potential pathogens. Electrospun membranes composed of PHB microfibers and Ag Nps were synthesized in a blend of DMF/chloroform at three different concentrations. Various studies were conducted on the characterization and antimicrobial activity of the membranes. The synthesized Ag Nps ranged from 4 to 8 nm in size. Furthermore, Young's modulus decreased, reducing from 13.308 MPa in PHB membranes without Ag Nps to 0.983 MPa in PHB membranes containing higher concentrations of Ag Nps. This demonstrates that adding Ag Nps results in a less stiff membrane. An increase in elongation at break was noted with the rise in Ag Nps concentration, from 23.597 % in PHB membranes to 60.136 % in PHB membranes loaded with Ag Nps. The antibiotic and antibiofilm activity of the membranes were evaluated against Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus mutans, and Candida albicans. The results indicated that all PHB membranes containing Ag Nps exhibited potent antibacterial activity by inhibiting the growth of biofilms and planktonic bacteria. However, inhibition of C. albicans occurred only with the PHB-Ag Nps C membrane. These findings emphasize the versatility and potential of Ag Nps-incorporated membranes as a multifunctional approach for preventing and addressing microbial infections associated with peri-implantitis. The combination of antibacterial and antibiofilm properties in these membranes holds promise for improving the management and treatment of peri-implantitis-related complications.

Modified Goldner Trichrome for Non-decalcified Mineralized Tissue Plastinated and Embedded in Resin / Tricrómico de Goldner Modificado para Tejido Mineralizado no Descalcificado Plastinado e Incluido en resina

SUMMARY: Over time, Goldner's trichrome staining has been essential in paraffin soft tissue research. However, its classic application involves prior decalcification, generating disadvantages in the integrity of the samples and the interpretation of results. This study seeks to overcome the limitations associated with decalcification when applying Goldner's trichrome stain with plastic resins. It focuses on detailed visualization of non-decalcified bone and dental samples in animal models. Samples of jaw and tooth from a dog (Canis familiaris) were used, as well as tibia from a rabbit (Oryctolagus cuniculus) with a titanium dental implant and bone graft substitute. Adjustments were made to the original protocol, including a surface treatment prior to staining. Plastination and inclusion in specific plastic resins were part of the process. The microplastinated and stained samples showed optimal quality for optical microscopy. Those from dogs allowed detailed observation of the tooth-periodontal tissue relationship, while those from rabbits revealed a clear differentiation between mineralized and osteoid bone tissue. The staining made it easy to examine the precise interface between soft tissues, bone graft, and implant. The successful adaptation of Goldner's trichrome stain to specimens in plastic resins represents a significant advance in histological investigation of hard tissues. This methodology stands out as an effective tool to evaluate implants and biomaterials in animal models, providing detailed visualization without compromising the integrity of the samples. The combination of histochemistry and plastic resins offers a valuable alternative for microanatomical studies, opening new possibilities in hard tissue research and evaluation of bone structures.

A lo largo del tiempo, la tinción tricrómica de Goldner ha sido esencial en la investigación de tejidos blandos en parafina. Sin embargo, su aplicación clásica conlleva la descalcificación previa, generando desventajas en la integridad de las muestras y la interpretación de resultados. Este estudio busca superar las limitaciones asociadas con la descalcificación al aplicar la tinción tricrómica de Goldner con resinas plásticas. Se enfoca en visualizar detalladamente muestras óseas y dentales no descalcificadas en modelos animales. Se emplearon muestras de mandíbula y diente de perro (Canis familiaris), así como tibia de conejo (Oryctolagus cuniculus) con implante dental de titanio y substituto de injerto óseo. Se realizaron ajustes al protocolo original, incluyendo un tratamiento superficial previo a la tinción. La plastinación y la inclusión en resinas plásticas específicas fueron parte del proceso. Las muestras microplastinadas y teñidas mostraron una calidad óptima para microscopía óptica. Las de perro permitieron la observación detallada de la relación diente-tejido periodontal, mientras que las de conejo revelaron una clara diferenciación entre tejido óseo mineralizado y osteoide. La tinción facilitó examinar la interface precisa entre tejidos blandos, injerto óseo e implante. La adaptación exitosa de la tinción tricrómica de Goldner a muestras en resinas plásticas representa un avance significativo en la investigación histológica de tejidos duros. Esta metodología destaca como una herramienta eficaz para evaluar implantes y biomateriales en modelos animales, brindando una visualización detallada sin comprometer la integridad de las muestras. La combinación de histoquímica y resinas plásticas ofrece una alternativa valiosa para estudios microanatómicos, abriendo nuevas posibilidades en la investigación de tejidos duros y evaluación de estructuras óseas.

Cervical necrotizing fasciitis caused by oral cavity infection: a case report considering therapeutic approach and its morphofunctional implications / Fascitis necrosante cervical causada por infección de la cavidad oral. Reporte de un caso considerando el abordaje terapéutico y sus implicaciones morfofuncionales

SUMMARY: Cervical necrotizing fasciitis (NF) is a rare complication of oral cavity infection with high morbi-mortality. Given its low prevalence, adequately reporting cases of NF, its therapeutic management, and associated morphofunctional modifications to the clinical and scientific community is pivotal. To that end, we herein describe a case of cervical NF in a 60-year-old patient with comorbidities and patient presented large, painful cervical swelling associated with a necrotic ulcer lesion in the anterior neck region. Intraoral examination indicated a periodontal abscess in the right mandibular area, while computed tomography indicated the lesion's extension from the right mandibular to the submandibular region. Following empirical intravenous antibiotic treatment, a broad surgical debridement was performed, and the foci of oral infection were removed. Debridement revealed communication between deep and superficial anatomical regions in the submandibular area, where we subsequently placed a Penrose drain. Biopsies showing acute inflammatory infiltrate associated with necrotic and hemorrhagic regions confirmed the diagnosis of NF. When an antibiogram revealed resistance to the empirical treatment, the antibiotic scheme was replaced with an adequate alternative. After a second debridement, we closed the defect with fascio-mucocutaneous advancement flaps with a lateral base while maintaining suction drainage. Having reacted positively, the patient was discharged 10 days after the operation. Despite an extensive morphofunctional change generated in the treated area, the patient showed no difficulties with breathing, phonation, swallowing, or mobilizing the area during control sessions. Altogether, this report contributes to the highly limited literature describing morphological aspects that can facilitate or delay the spread of infection or the morphofunctional disorders associated with the size and depth of surgical interventions for cervical NF, information that is relevant for the comprehensive, long-term prognosis of the treatment of NF.

La fascitis necrosante (FN) cervical es una rara complicación de una infección proveniente de la cavidad bucal asociada a una alta morbimortalidad. Por lo anterior, es fundamental informar a la comunidad clínica y científica los casos de FN, su manejo terapéutico y las modificaciones morfofuncionales asociadas. Se describe un caso de FN cervical en una paciente de 60 años quien presentó una gran tumefacción dolorosa asociada a una lesión ulcerosa necrótica en la región anterior del cuello. El examen intraoral mostró un absceso periodontal en el área mandibular derecha y la tomografía computarizada mostró la extensión de la lesión hacia la región submandibular. Tras el tratamiento antibiótico empírico, se realizó un desbridamiento quirúrgico extenso y se extirparon los focos de infección oral. El desbridamiento reveló comunicación entre las regiones anatómicas profundas y superficiales del área submandibular, donde se colocó un drenaje Penrose. Las biopsias mostraron un infiltrado inflamatorio agudo asociado con regiones necróticas y hemorrágicas, confirmando el diagnóstico de FN. El antibiograma reveló resistencia al tratamiento empírico, por lo que el esquema antibiótico se sustituyó. Tras un segundo desbridamiento, se cerró el defecto con colgajos de avance fascio-mucocutáneos de base lateral manteniendo drenaje aspirativo. El positivo progreso del paciente permitió su alta 10 días después. Aun cuando se generó una gran modificación morfofuncional en el área tratada, la paciente no presentó dificultades para respirar, hablar, deglutir o movilizar el área cervical intervenida durante las sesiones de control. Este informe contribuye a la limitada literatura que describe los aspectos morfológicos que pueden facilitar o retrasar la propagación de la FN y las consecuencias asociadas a los trastornos morfofuncionales provocadas por el tamaño y profundidad de las intervenciones quirúrgicas requeridas por la FN, información relevante para el pronóstico integral a largo plazo del tratamiento de la FN.

Immediate small-diameter implants as abutments for an overdenture in the edentulous atrophic mandible: report of immersion endoscopic bone in vivo, and histologic bone-implant evaluation after 6 months of function / Implantes de pequeño diámetro como soporte inmediato de sobredentaduras en hueso alveolar mandibular atrófico: reporte de endoscopía de inmersion in vivo y evaluación histológica a los 6 meses de función

The aim of this report was to endoscopically evaluate bone quality in vivo in the immediate installation of temporary small-diameter implants, and again after 6 months of function, through an attachments system for overdenture, in the atrophic mandible of a patient. We also histologically evaluated bone-implant interaction in these temporary small-diameter implants, once the success of the osseointegration of the submerged implants was guaranteed. A patient received a total of 6 implants in the atrophic mandible, two of which were immediately loaded with a provisional prosthesis, and four were left to heal in a submerged way. Further, an immersion endoscopic evaluation was performed during bone drilling, and this showed a compact bone structure with limited vascularization and predominantly cortical structure.This immediate loading protocol involving an overdenture retained by two small-diameter implants of 2.9 mm in the atrophic mandible proved to be successful after 6 months of loading. Clinical and histologic osseointegration was consistently achieved for both of the retrieved immediately loaded implants. This modality allows the patient to be restored with a stable, functional, and aesthetic prosthesis during the osseointegration period of submerged implants and soft-tissue healing, before the removal of the provisional implants. The histological evaluation of bone-implant contact found that the space between the implant threads closer to the surface was filled with woven bone and lamellar bone, but the tissue in contact with the cervical portion of the implants was compatible with cortical bone organization. Also, the newly formed bone has a regular cell distribution and characteristics of advanced maturation after 6 months of function in the atrophic mandible. Anchored overdentures in 2 to 4 small-diameter implants (2.9 mm) for edentulous patients with severe atrophy of the mandible with cortical bone would be a minimally invasive alternative.

Changes in morphology of alveolar buccal walls following atraumatic internal root fragmentation / Cambios en la morfología de las paredes alveolares bucales después de fragmentación radicular interna atraumática

The buccal alveolar wall represents the most important structure to provide shape and volume of the alveolous following tooth extraction. The aim of the study was the evaluation of buccal alveolar bone structures following minimally invasive surgery. In 15 patients (3 male, 12 female), aged 20­67 years, 3 central incisors, 5 lateral incisors, and 7 bicuspids were removed using flapless enucleation. The enucleation comprised endoscopically assisted mesiodistal root sectioning with inward fragmentation of the oral and apical parts followed by internal reduction of the buccal root lamella. Buccal bone height before extraction was 10.61 mm, following extraction 10.50 mm. Crestal width of the buccal bone plate was 1.11 mm before and 1.40 mm after tooth removal. Apical buccal bone width before was 0.66 mm and after extraction 0.40 mm. Gingival height was 13.58 mm before and 13.56 mm following extraction. Following transalveolar enucleation, the buccal alveolar bone wall remains unchanged concerning height and crestal width.

La pared alveolar bucal representa la estructura más importante para proveer la forma y el volumen de los alveólos dentales posterior a la extracción dental. El objetivo del estudio fue evaluar las estructuras de hueso alveolar bucal después de la cirugía mínimamente invasiva. En 15 pacientes (3 hombres, 12 mujeres), con edades entre 20 a 67 años, 3 incisivos centrales, 5 incisivos laterales y 7 premolares fueron removidos utilizando enucleación sin colgajo. La enucleación comprende el seccionamiento mesio-distal de la raíz dental endoscópicamente asisitido a través de fragmentación interna de la porción lingual y apical radicular y posteriomente una reducción interna de la lamela de raíz bucal. La altura ósea bucal antes de la extracción fue 10,61 mm y después de la extracción fue 10,50 mm. La anchura de la cresta ósea bucal fue 1,11 mm y 1,40 mm después de la extracción del diente. El grosor del hueso apical antes de la extracción fue 0,66 mm y 0,40 mm después de la extracción. La altura gingival fue 13,58 mm antes de la extracción y 13,56 mm después de la extracción. Después de la enucleación transalveolar, la pared del hueso alveolar bucal se mantiene sin cambios en relación con la altura y del grosor del reborde alveolar.

Exclusion of PAX9 and MSX1 mutation in six families affected by tooth agenesis. A genetic study and literature review

OBJECTIVES: In the present study, it is described the phenotypical analysis and the mutational screening, for genes PAX9 and MSX1, of six families affected by severe forms of tooth agenesis associated with other dental anomalies and systemic entities. Study DESIGN: Six families affected by severe tooth agenesis associated with other dental anomalies and systemic entities were included. Oral exploration, radiological examination, medical antecedents consideration and mutational screening for PAX9 and MSX1 were carried out. RESULTS: No mutations were discovered despite the fact that numerous teeth were missing. An important phenotypical variability was observed within the probands, not being possible to establish a parallelism with the patterns associated to previously described PAX9 and MSX1 mutations. CONCLUSIONS: These results bring us to conclude that probably other genes can determine phenotypical patterns of dental agenesis in the families studied, different than the ones described in the mutations of PAX9 and MSX1. Moreover, epigenetic factors can be involved, as those that can reduce gene dosage and other post-transcriptional modulation agents, causing dental agenesis associated or not with systemic anomalies

No disponible

Bone healing in transverse maxillary defects with different surgical procedures using anorganic bovine bone in humans / Recuperación ósea en defectos maxilares transversales con distintos procedimientos quirúrgicos utilizando hueso bovino inorgánico en humanos

The centripetal resorption of maxilla is a continuous process after tooth loss. For treatment of deficient bone sites, autologous bone grafts may be used, as an alternative, biomaterials can be applied which do not require intra- or extraoral donor sites. The present report we describe the use of anorganic bovine bone (ABB) based on three case reports under different modes: Membrane, rigid barrier and connective tissue graft. Clinical results show that under all conditions, sufficient hard tissue was formed to allow implant born rehabilitation in the former insufficient bone sites. Histologic evaluation revealed trabecular bone in an almost mature matrix with resting particles of ABB. Depending on the original site situation, two step rigid occlusive barrier concept may be applied, if resting bone does not provide implant stability, whereas membrane covered augmentation in combination with connective tissue is recommended if simultaneous implant insertion is possible.

La reabsorción centrípeta del maxilar es un proceso continuo después de la pérdida dentaria. Para el tratamiento de sitios óseos deficientes, se pueden utilizar injertos de hueso autólogo; como alternativa, se puede aplicar biomateriales, que no requieren sitios donantes intra o extraorales. Se describe el uso de hueso inorgánico bovino (HIB) base en tres casos en diferentes modos: membrana, barrera rígida e injerto de tejido conectivo. Los resultados clínicos muestran que en todas las condiciones se formó suficiente tejido duro para permitir la rehabilitación de implantes en los sitios de hueso insuficiente. La evaluación histológica reveló hueso trabecular en una matriz casi madura con partículas en reposo de HIB. Dependiendo de la situación del sitio original, se puede aplicar el concepto de barrera oclusiva rígida en dos pasos, si el hueso en reposo no proporciona la estabilidad del implante, mientras que el aumento cubierto con membrana en combinación con tejido conectivo se recomienda si es posible la inserción simultánea de implantes.

Mandible measurements and dental midline deviation after alveolar nerve transection in growing rabbits / Medidas mandibulares y desviación de la línea mediana dental luego de la transección del nervio alveolar inferior en conejos en crecimiento

The relationship between sensitive innervation and normal mandibular bone development has been described in the literature. Therefore, neural damage is a potential cause of osseous deformities, particularly in growing subjects. The aim of this project is to present the mandible measurements obtained after the transection of the inferior alveolar nerve of growing rabbits. A specific surgical protocol was designed to carry out the unilateral nerve transection by avoiding musculoskeletal injuries. Twenty New Zealand White rabbits one week post-weaning were used, 12 as an experimental group and 8 as a control group (Sham operated). The animals were sacrificed 90 days postoperatory, and the mandibles carefully dissected. Dental midline deviation data were obtained under anesthesia, previous to sacrifice. All measurements were obtained with a micron digital caliper. For this study, only anterior-posterior measurements were obtained from five points specifically determined on the rabbit mandible. Each measurement was made three times by the same examiner and the average value was considered. Regarding the anterior-posterior measurements, the molar and incisive regions of the denervated hemimandible were significantly shorter than the corresponding regions in the non-denervated side. The control group did not show these differences. A dental midline deviation was observed, but not always directed on the operated side. However, the deviation values were greater when oriented to the denervated side. These changes did not cause evident deformity or dysfunction in the masticatory system of the animals. They were fed normally and their weight was considered within normal parameters while growing. Despite the biological relationship between sensory inervation and bone morphology, the effect of sensory denervation in early stages of bone growth appears to generate only small alterations on the mandible morphology. However, these alterations do not lead to functional proble...

Se ha descrito una importante relación entre la inervación sensitiva y aspectos biológicos mandibulares. Consecuentemente, el daño a la estructura nerviosa es una causa potencial de alteraciones en el desarrollo mandibular, sobre todo en etapas de crecimiento. El objetivo de este trabajo es presentar mediciones mandibulares realizadas posterior a una lesión del nervio sensitivo en una etapa temprana de crecimiento. Se diseñó un protocolo quirúrgico para realizar la transección del nervio alveolar inferior sin lesionar estructuras musculoesqueléticas. Veinte conejos Neo zelandeses blancos fueron utilizados, una semana post-destete, 12 como grupo experimental y 8 como grupo control. Los animales fueron sacrificados 90 días después y las mandíbulas cuidadosamente disecadas. La información de la desviación de la línea media se obtuvo bajo anestesia, previo al sacrificio. Todas las mediciones se obtuvieron con un calibrador digital. Las medidas antero-posteriores se obtuvieron a partir de cinco puntos específicamente determinados en la mandíbula del conejo. En cuanto a las medidas antero-posteriores, las región molar e incisiva de las hemimandíbulas denervadas fueron significativamente menores que la correspondiente del lado no denervado. El grupo control no mostró esta diferencia. La línea media dental siempre se observó desviada, pero no siempre hacia el lado intervenido. Sin embargo, la media de desviación fue mayor cuando ésta se orientó hacia el lado denervado. Estos cambios no causaron deformidad evidente o disfunción en el sistema masticatorio de los animales, los cuales se alimentaron normalmente. El peso de los mismos fue considerado dentro de los parámetros normales. A pesar de la relación biológica entre la inervación sensitiva y la morfología del hueso, el efecto de la denervación sensitiva en las primeras etapas de crecimiento parece generar sólo pequeñas alteraciones en la morfología mandibular. Sin embargo, éstas no conducen a problemas funcionales...

Inervación sensitiva y crecimiento mandibular: propuesta de modelo experimental para acceso quirúrgico al nervio alveolar inferior preservando estructuras musculoesqueléticas en conejo New Zealand White pos-destetados / Sensitive inervation and mandibular growth: a novel proposal for a surgical access to inferior alveolar nerve preserving musculoskeletal health in post-weaned New Zealand White rabbit

Numerosos estudios reflejan vínculos entre la inervación sensitiva y el desarrollo de la estructura ósea mandibular. Con la finalidad de obtener un modelo in vivo para estudiar el efecto de la alteración de la inervación sensitiva sobre el crecimiento mandibular, se propone un acceso quirúrgico al nervio alveolar inferior que evita dañar las estructuras músculo-esqueléticas consideradas esenciales en el crecimiento craneofacial. El modelo utilizado fue el conejo New Zealand White post-destetado. Primera etapa: se realizó un estudio mediante disección anatómica para elegir una vía de acceso quirúrgico. Se eligió el acceso por la región submandibular. Desde esta zona, se accede al nervio en su punto de ingreso al canal mandibular, entre la rama mandibular y el músculo pterigoideo medial. Segunda etapa: Se utilizaron 12 especímenes a los cuales se aplicó el procedimiento quirúrgico diseñado con ayuda y supervisión veterinaria. Posteriormente, los animales fueron controlados bajo condiciones estandarizadas durante 90 días. Se evaluaron los siguientes aspectos: 1. Progreso de curación de herida quirúrgica; 2. Se utilizó un protocolo de valoración de aplicabilidad del diseño quirúrgico basado en las directrices generales de Morton y Griffitt para detección de dolor y disconfort en animales de experimentación y las directrices específicas del Southwestern Medical Center para evaluación de dolor y disconfort en conejos. Según los parámetros analizados, no se observaron valores indicadores de inaplicabilidad del protocolo propuesto. El progreso de la herida quirúrgica se consideró normal. Estudios que analizan la participación de la inervación sensitiva en aspectos fisiológicos mandibulares muestran vías quirúrgicas para modificar la estructura nerviosa que implican alteraciones musculoesqueléticas. El procedimiento aquí presentado preserva estas estructuras y es bien tolerado por este animal en etapas tempranas de crecimiento. En consecuencia resulta una alternativa ...

Numerous studies have shown links between sensory inervation and mandibular bone development. In order to obtain an in vivo model to study the effect of altered sensory innervation on mandibular growth, a surgical approach for the inferior alveolar nerve transsection is proposed. This procedure avoids damage to muscular or skeletal structures that are considered essential in craniofacial growth. New Zealand White rabbits post-weaning were used. First stage: morphological study by anatomical dissection for choosing a surgical portal. The access chosen for the intervention was the submandibular region. From this area, it is possible to access the point where the nerve is entering into the mandibular canal, between the Ramus Mandibular and the Medial Pterygoid Muscle. Second stage: 12 specimens were submitted to the proposed surgical procedure under veterinary supervision. Subsequently, the animals were monitored under standard conditions for 90 days. The following aspects were evaluated: 1. Surgical wound healing; 2. A double protocol for assessing applicability of surgical design was used. The first was based on Morton and Griffitt general guidelines to detect pain and discomfort in experimental animals and the second was based on the Southwestern Medical Center guidelines for evaluation of pain and discomfort in rabbits. The progress of the surgical wound was considered normal. According to the parameters analyzed, the values obtained indicate that the protocol is applicable to the surgical procedure. Studies examining the contribution of sensory inervation concerning physiological aspects of the mandibular bone employ surgical methods to modify the nervous structure, thus provoking musculoskeletal disorders. The procedure presented here preserves these structures and is well tolerated by the animal in early stages of growth. For that reason, this method is a feasible alternative for studying the participation of sensory innervation in mandibular growth.