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.

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.

Modified Goldner Trichrome for Non-decalcified Mineralized Tissue Plastinated and Embedded in Resin

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.

Relationships between Clinical and Non-Clinical Variables concerning Traumatic Dental Injuries in Deciduous Teeth Attended in a Children's Hospital.

This study aimed to describe Traumatic Dental Injuries (TDI) in a child population, with a discussion focused on the impact of non-clinical variables on TDI. A cross-sectional, descriptive, and relational study about TDI in deciduous dentition in a children's hospital was performed. A total of 166 patients were included, of which 51.8% were male and 48.2% were female. Subluxation was the most observed injury (37.5%), and high-severity lesions predominated (60.2%). Regarding non-clinical variables, 89.2% of the patients attended urgent care centers within 24 h, and 43.4% within the first 3 h. Pointed objects were the leading cause of TDI (47%). Most TDIs were concentrated between the ages of 2 and 4 (53.5%). Concerning the place of TDI occurrence, the school (41.6%) was associated with faster urgent dental care attendance, and the home (37.3%) was associated with TDI occurrence in children under 2 years of age. Previous TDI experience (24.1% of patients) did not generate differences in the time interval between the TDI and arrival at the hospital, compared with children without a TDI history. While the behavior of clinical variables agrees with the literature reviewed, several non-clinical variables show wide differences. There is a need to identify the non-clinical variables that can significantly interact with phenomena specific to the study population (social, demographic, and cultural). The study of these variables can be useful in applying health policies. In the group studied, the non-clinical data reveals the need to educate parents or guardians on the importance of timely care in TDI, the long-term consequences of traumatism affecting deciduous dentition, and the implication of the maturation of the child's motor skills in TDI.

Osteoinductive Electrospun Scaffold Based on PCL-Col as a Regenerative Therapy for Peri-Implantitis.

Peri-implantitis is a serious condition affecting dental implants that can lead to implant failure and loss of osteointegration if is not diagnosed and treated promptly. Therefore, the development of new materials and approaches to treat this condition is of great interest. In this study, we aimed to develop an electrospun scaffold composed of polycaprolactone (PCL) microfibers loaded with cholecalciferol (Col), which has been shown to promote bone tissue regeneration. The physical and chemical properties of the scaffold were characterized, and its ability to support the attachment and proliferation of MG-63 osteoblast-like cells was evaluated. Our results showed that the electrospun PCL-Col scaffold had a highly porous structure and good mechanical properties. The resulting scaffolds had an average fiber diameter of 2-9 µm and high elongation at break (near six-fold under dry conditions) and elasticity (Young modulus between 0.9 and 9 MPa under dry conditions). Furthermore, the Col-loaded scaffold was found to decrease cell proliferation when the Col content in the scaffolds increased. However, cytotoxicity analysis proved that the PCL scaffold on its own releases more lactate dehydrogenase into the medium than the scaffold containing Col at lower concentrations (PCL-Col A, PCL-Col B, and PCL-Col C). Additionally, the Col-loaded scaffold was shown to effectively promote the expression of alkaline phosphatase and additionally increase the calcium fixation in MG-63 cells. Our findings suggest that the electrospun membrane loaded with Col can potentially treat peri-implantitis by promoting bone formation. However, further studies are needed to assess the efficacy and safety of this membrane in vivo.

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.

Declarative knowledge in oral health: The case of the term 'centric occlusion'.

INTRODUCTION: The lack of academic agreement in the practical or clinical use of declarative knowledge can generate unnecessary confusion and miscommunication. The concept Centric Occlusion (CO) is part of the body of declarative knowledge in dentistry, but its definition remains unclear. OBJECTIVE: To ascertain the CO concept in articles published in dental journals as a study case for the dentistry "corpus" of declarative knowledge. METHODOLOGY: The alternative definitions of CO used by the GPT (Glossary of Prosthodontic Terms) from 1956-1977, 'CO as a synonym for maximum intercuspal contact (MIC)', or by the GPT from 1987-2017, 'CO may or may not coincide with MIC', were searched in the articles. The association between the CO definition used and variables such as article aims, journal scope and authors specialty was assessed. RESULTS: Eight hundred and twelve articles were analysed. The widespread use of CO as synonym of MIC was the main finding and was significantly associated to the Orthodontics field. The CO definition according to the GPT 1987-2017 was less frequently observed but appeared in all dentistry fields, showing a significant association with the Oral Rehabilitation field. The difficulty of incorporating the current definition of CO (by GPT) into the main clinical discussions was evidenced all the long of the review process. CONCLUSION: The lack of consensus in the concept use was confirmed by the present study case, showing the influence of specific fields in Oral Health declarative knowledge. This methodology can provide a tool to the academy to assess controversial terms or concepts in Oral Health education, thus facilitating the critical and reflexive learning by students.

Moderate and Severe Dental Fluorosis in the Rural Population of Anantapur, India: Change in Their Biological Susceptibility?

Dental fluorosis affects the quality of life. A cross-sectional, observational study was conducted in a community affected by endemic fluorosis for several generations with a conserved biological and social environment. The study included patients from the rural population of Anantapur, India. The Dean index (DI) and the Thylstrup and Fejerskov Index (TFI) were used for fluorosis classification. Additionally, water samples were collected for fluoride analysis, taken from the patients' living areas. The statistical association between the variables was analyzed. In total, 785 patients between 10 and 60 years old were included in the study (58.7% women and 41.3% men). Fluorosis signs were found in 94.6% of patients examined using the DI and 94.4% using the TFI. Moderate-severe dental fluorosis was observed in 62.8% by DI and 73.1% by TFI consuming untreated water with up to 2.9 ppm of fluoride. Furthermore, moderate-severe dental fluorosis was observed in 33.2% by DI and 39.9% by TFI consuming water with ≤1.5 ppm of fluoride. The high prevalence of moderate-severe dental fluorosis in patients consuming water with a low fluoride concentration suggests that other factors are involved. Biological susceptibility change could play an essential role in the severity of dental fluorosis in populations exposed for several generations, affecting its actual and future quality of life.

Genetic Polymorphisms Associated with Early Implant Failure: A Systematic Review.

PURPOSE: Early implant failures have been observed in dental implant treatments even when the procedures are performed under appropriate conditions and in patients without local or systemic contraindications, suggesting that an intrinsic component of the patient could modify the osseointegration process. The objective of this systematic review was to analyze the association between early implant failure and genetic polymorphisms. MATERIALS AND METHODS: A systematic search was performed in the PubMed, ScienceDirect, and Scopus databases using the PRISMA statement as the main guidelines and "Dental implant" AND "Polymorphism" as search terms. The search cutoff date was August 2019. In addition, the risk of bias, methodologic quality, and heterogeneity of the included studies were analyzed. RESULTS: The search strategy yielded 225 articles, and the titles and abstracts were reviewed to evaluate if they were relevant to the subject. Twenty-four articles were selected for a complete reading, of which 10 articles met the inclusion criteria. Finally, five studies citing the association of the following polymorphisms with early implant failure were chosen: G-1607GG of the MMP 1 gene, C-799T of the MMP 8 gene, and -77 A>G of the gene MMP 13. CONCLUSION: The polymorphisms analyzed are from the promoter region, generating altered cellular transcriptional activity for MMP 1, MMP 8, and MMP 13, the effects of which are observed in inflammation and extracellular matrix degradation. Establishing a relationship between genetic polymorphisms and phenomena such as early implant loss is necessary for the development of precision medicine in the field of dentistry.

Nanostructured Zn-Substituted Monetite Based Material Induces Higher Bone Regeneration Than Anorganic Bovine Bone and ß-Tricalcium Phosphate in Vertical Augmentation Model in Rabbit Calvaria.

The capacity of a nanostructured multicomponent material composed of Zn-substituted monetite, amorphous calcium phosphate, hydroxyapatite and silica gel (MSi) to promote vertical bone augmentation was compared with anorganic bovine bone (ABB) and synthetic ß-tricalcium phosphate (ß-TCP). The relation between biological behavior and physicochemical properties of the materials was also studied. The in vivo study was conducted in a vertical bone augmentation model in rabbit calvaria for 10 weeks. Significant differences in the biological behavior of the materials were observed. MSi showed significantly higher bone regeneration (39%) than ABB and ß-TCP (24%). The filled cylinder volume was similar in MSi (92%) and ABB (91%) and significantly lower in ß-TCP (81%) implants. In addition, ß-TCP showed the highest amount of non-osteointegrated particles (17%). MSi was superior to the control materials because it maintains the volume of the defect almost full, with the highest bone formation, the lowest number of remaining particles, which are almost fully osteointegrated and having the lowest amount of connective tissue. Besides, the bone formed was mature, with broad trabeculae, high vascularization and osteogenic activity. MSi resorbs gradually over time with an evident increment of the porosity and simultaneous colonization for vascularized new bone. In addition, the osteoinductive behavior of MSi material was evidenced.

Sinus Floor Augmentation by Intraoral Endoscopic Approach for Biomaterial Study in a Rabbit Model.

AIM: To develop a new surgical model for sinus floor augmentation (SFA) in rabbit for experimental purposes. MATERIALS AND METHODS: Eight adult rabbits were used, two for a surgical design using the anatomical dissection study, and the other six for an endoscopically assisted intraoral approach of SFA unilaterally, creating a subantral space where an allograft biomaterial was deposited. SFA was verified through cone-beam computerized tomography. Healing, weight, food, feces, and behavior were evaluated for 4 weeks post-operatively. RESULTS: All animals survived. There was no bleeding or infection; inflammation was mild. No changes were observed in terms of feeding, weight, feces, or behavior. Tissue healing was normal. CONCLUSION: This model is a refinement of the experimental technique and is a real option for SFA, without compromising animal morbidity because of its conservative design. The minimally invasive approach with endoscopic assistance reduces bias and improves surgical predictability.

A Regenerative Endodontic Approach in Mature Ferret Teeth Using Rodent Preameloblast-conditioned Medium.

BACKGROUND: This study evaluated the effectiveness of a regenerative endodontic approach to regenerate the pulp tissue in mature teeth of ferret. The presence of odontoblast-like cells in the newly-formed tissue of teeth treated with or without preameloblast-conditioned medium was evaluated based on morphological criteria. MATERIALS AND METHODS: Twenty-four canines from six ferrets were treated. The pulp was removed, and the apical foramen was enlarged. After inducing the formation of a blood clot, a collagen sponge with or without preameloblast-conditioned medium was placed underneath the cementoenamel junction. The samples were analyzed at the eighth week of follow-up. RESULTS: Vascularized connective tissue was observed in 50% of teeth, without differences between groups. The tissue occupied the apical third of the root canals. Odontoblast-like cells were not observed in any group. CONCLUSION: Revitalization of mature teeth is possible, at least in the apical third of the root canal. Further experimental research is needed to produce more reliable outcomes.

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.

Vascular labeling of the head and neck vessels: Technique, advantages and limitations.

BACKGROUND: Vascular staining techniques have been used to describe the vascular structures of several anatomic areas. However, few reports have described this procedure in the head and neck region. This paper describes a head and neck vascular labeling procedure, and describes some of the technical complications that may occur. MATERIAL AND METHODS: Fifteen specimen cadaver heads were prepared. After drying the vascular system, the internal carotid arteries were ligated and a solution with latex and a gelling agent was injected into the internal carotid arteries and external jugular veins. Two different colors were employed to differentiate arteries from veins. A total of 60ml latex was injected into each blood vessel. Subsequently, the specimens were refrigerated at 5°C for a minimum of 24 hours. Finally, a dissection was performed to identify the venous and arterial systems of the maxillofacial region. RESULTS: In most specimens, correct identification of the vascular structures (lingual artery, pterigoyd plexus, and the major palatal arteries, among others) was possible. However, in three heads a major technical problem occurred (the latex remained liquid), making the dissection unfeasible. Other minor complications such as latex obstruction due to the presence of atheromas were found in two further specimens. CONCLUSIONS: The vascular labeling technique is a predictable, effective and simple method for analyzing the vascular system of the maxillofacial area in cadaveric studies, including vessels of reduced diameter or with an intraosseous course. This procedure can be especially useful to teach vascular anatomy to dental students and postgraduate residents. Key words:Blood vessels, vascular casting, vascular labeling, head and neck arteries, carotid arteries, jugular veins.

Vascular Structures of the Lateral Wall of the Maxillary Sinus: A Vascular Labeling Technique.

PURPOSE: Sinus floor augmentation is a common procedure in implant dentistry. However, several intraoperative complications can occur during this procedure, such as bleeding from the lateral wall of the maxillary sinus. The aim of this study was to describe the vascular structures of the lateral wall of the maxillary sinus using a vascular labeling technique. MATERIALS AND METHODS: Ten cadaveric specimens were prepared by the vascular labeling technique. Liquid latex was injected into the large vessels of the head, and the lateral wall of the maxillary sinus was exposed by dissection. The diameter of the vessels and their distance from the alveolar ridge (AR) were recorded. RESULTS: Blood vessels could be observed in all the dissected specimens (100%). The mean distance from the lower edge of the blood vessels to the AR was 18.5 mm (SD 3.31 mm). CONCLUSIONS: The vascular labeling technique detects maxillary sinus vessels in a predictable and effective way. These structures are clinically relevant because they are located in the area where the lateral window is usually created in sinus augmentation procedures and can cause profuse bleeding.

Novel use of cranial epidural space in rabbits as an animal model to investigate bone volume augmentation potential of different bone graft substitutes.

BACKGROUND: The success of bone augmentation to a major degree depends on the biomechanics and biological conditions of the surrounding tissues. Therefore, an animal model is needed providing anatomical sites with similar mechanical pressures for comparing its influence on different biomaterials for bone regeneration. The present report describes the new bone formation associated to biomaterial in a bursa created in the epidural space, between dura mater and cranial calvaria, under the constant pressure of cerebrospinal fluid. METHODS: Five adult California rabbits were used for the trial. In each animal, two bursae were created in the epidural spaces, in the anterior part of the skull, below both sides of the interfrontal suture. The spaces between dura mater and cranial calvaria were filled with in-situ hardening biphasic calcium phosphate containing hydroxyapatite and beta tricalcium-phosphate (BCP), in-situ hardening phase-pure beta-tricalcium phosphate (ß-TCP) or without any biomaterials (sham). After 90 days, the animals were sacrificed, and the defect sites were extracted and processed for histomorphometric analysis by optical and backscattered electron microscopy. RESULTS: The cranial epidural spaces created (n = 10) could be preserved by the application both BCP (n = 3) and ß-TCP biomaterials (n = 3) in all experimental sites. The sites augmented with BCP showed less new bone formation but a trend to better volume preservation than the sites augmented with ß-TCP. However, the bone in the BCP sites seemed to be more mature as indicated by the higher percentage of lamellar bone in the sites. In contrast, the created space could not be preserved, and new bone formation was scarce in the sham-operated sites (n = 4). CONCLUSION: The experimental bursae created bilaterally in the epidural space allows comparing objectively bone formation in relation to biomaterials for bone regeneration under permanent physiological forces from cerebrospinal fluid pressure.

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

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