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.

The applications of the plasma matrix in the treatments of dental pulp and periapical diseases / 口腔疾病防治

@#The plasma matrix is a kind of autologous blood conduct. It has been widely used in maxillofacial tissue regeneration, skin cosmetology and some other fields. Recently, to preserve the dental pulp as well as the teeth, pulp regeneration therapy and apical surgery have become increasingly important as well as the applications of bioactive materials. As a kind of autologous bioactive material, the plasma matrix has some natural advantages as it is easy to obtain and malleable. The plasma matrix can be used in the following cases: ①pulp revascularization of young permanent teeth with open apical foramina that cannot stimulate apical bleeding; ② apical barrier surgery with bone defects and large area perforation repair with bone defects or root sidewall repair surgery; ③ apical surgeries of teeth with large area of apical lesions, with or without periodontal diseases. The plasma matrix is a product derived from our blood, and there are no obvious contraindications for its use. Several systematic reviews have shown that the plasma matrix can effectively promote the regenerative repair of dental pulp in patients with periapical diseases. However, the applications of plasma matrix are different because its characteristics are affected by different preparation methods. In addition, there is still a lack of long-term clinical researches on the plasma matrix, and the histological evidences are difficult to obtain, so a large number of in vitro and in vivo experimental studies are still needed. This article will describe the applications of different kinds of plasma matrix for dental pulp regeneration and bone tissue regeneration in apical surgeries to provide references for clinicians in indication selection and prognosis evaluation.

Observation on A-PRF promoting regeneration of osteochondral defects in rabbit knee joints / 上海交通大学学报（医学版）

Objective·To explore the role of advanced platelet-rich fibrin(A-PRF)in osteochondral regeneration.Methods·Bone-marrow mesenchymal stem cells(BMSCs)and knee joint chondrocytes were obtained from New Zealand rabbits.A-PRF was obtained by low-speed centrifugation of the heart blood of rabbits.The histological structure of A-PRF was observed by an optical microscope.The release of growth factors in A-PRF was detected by ELISA,including platelet-derived growth factor,transforming growth factor-β,insulin-like growth factor,vascular endothelial growth factor,epidermal growth factor and fibroblast growth factor.A-PRF's cytotoxicity and capability for promoting the proliferation of rabbit BMSCs were detected by live/dead double staining and MTT methods.The effect of A-PRF on the gene expression of type Ⅱ collagen,aggrecan,alkaline phosphatase(ALP)and osteocalcin(OCN)in rabbit BMSCs was detected by real-time fluorescence quantitative polymerase chain reaction(qRT-PCR).Transwell chambers were used to determine the effect of A-PRF on the migration ability of rabbit BMSCs and the chondrocytes.Rabbit knee osteochondral defect models were established,and 18 rabbits were randomly divided into 3 groups.The A-PRF group(n=6)was implanted with A-PRF in the defect,the A-PRF+BMSCs group(n=6)was implanted with rabbit BMSCs on A-PRF,and the control group(n=6)did not undergo implantation.The rabbits were sacrificed 12 weeks after surgery and the knee joint specimens were stained with hematoxylin-eosin(H-E),toluidine blue and safranin O/fast green.Based on the surface morphology and histology of the knee joints,the International Cartilage Repair Society(ICRS)scoring system was used for macroscopic and histological scoring.Results·A-PRF had a loose network structure and can slowly release growth factors.No cytotoxicity to rabbit BMSCs was observed after adding A-PRF,and the the capability for promoting the proliferation of rabbit BMSCs was significantly increased at 24,48 and 72 h after adding A-PRF(all P<0.05).Chondrogenesis-related gene Ⅱ collagen and aggrecan,as well as osteogenesis-related genes ALP and OCN were significantly up-regulated(all P<0.05).After adding A-PRF,the migration abilities of rabbit BMSCs and chondrocytes were significantly enhanced(both P<0.05),and the migration ability of rabbit BMSCs was significantly higher than that of chondrocytes(P=0.025).The joint surface morphology in the rabbit knee joint defect models was observed.It can be seen that the defects in the A-PRF group and the A-PRF+BMSCs group were basically restored,while the the defects in the control group were only covered by soft tissue.In the ICRS macroscopic score,there was no statistical difference between the A-PRF group and the A-PRF+BMSCs group,but the scores of the two groups were all significantly higher than those of the control group(all P<0.05).According to the histological results,both the A-PRF group and the A-PRF+BMSCs group formed osteochondral repair,but the cartilage in the A-PRF group was more mature,while the control group formed fibrous repair.In the ICRS histological score,there was no statistical difference between the A-PRF group and the A-PRF+BMSCs group,but the scores of both the groups were significantly higher than those of the control group(both P<0.05).Conclusion·Autologous A-PRF has good biocompatibility and the capability for promoting the proliferation of BMSCs.It can promote the repair of cartilage and subchondral bone both in vitro and in vivo.

Electrospun nanofiber scaffolds for soft and hard tissue regeneration / 中国组织工程研究

BACKGROUND:Currently,electrospun nanofibers,which are biomimetic materials of natural extracellular matrix and contain a three-dimensional network of interconnected pores,have been successfully used as scaffolds for various tissue regeneration,but are still faced with the challenge of extending the biomaterials into three-dimensional structures to reproduce the physiological,chemical as well as mechanical properties of the tissue microenvironment. OBJECTIVE:To summarize the process and principles of electrostatic spinning and to explore the applications of the resulting electrospun nanofibers in tissue regeneration of skin,blood vessels,nerves,bone,cartilage and tendons/ligaments. METHODS:With"electrospinning,electrospun nanofibers,electrospun nanofiber scaffolds,tissue regeneration"as the Chinese and English search terms,Google Academic Database,PubMed,and CNKI were searched,and finally 88 articles were included for review. RESULTS AND CONCLUSION:(1)The electrospun nanofibers are a natural fibrous extracellular matrix mimetic material and contain a three-dimensional network of interconnected pores that have been successfully used as scaffolds for a variety of tissue regeneration applications.(2)Several papers have described the great potential of electrospun nanofiber scaffolds applied to the regeneration of skin,blood vessels,nerves,bones,cartilage and tendons/ligaments,providing a solid theoretical basis for its final application in clinical disease treatment,or for its transformation into practical products to enter the market.(3)However,the current research results are mostly based on cell experimental research results in vitro,and whether it can be finally applied to human body still needs clinical verification.(4)At present,many kinds of electrospun products for various clinical needs have been commercialized in and outside China,indicating that the research field of electrospun nanofiber scaffolds for soft and hard tissue regeneration has great research value and application potential.

Potential and advantages of metal organic frameworks-based hydrogel materials for repairing soft and hard tissues / 中国组织工程研究

BACKGROUND:Due to the mechanical properties,unstable drug release,single function and other problems of pure hydrogel materials,in recent years,researchers have prepared a variety of metal organic frameworks-based hydrogel materials by introducing metal organic frameworks into hydrogel,and showed great potential in the field of soft and hard tissue regeneration. OBJECTIVE:To classify the metal organic frameworks-based hydrogel materials based on how metal organic frameworks enhance the properties of hydrogel and further summarize its recent research in the field of soft and hard tissue regeneration,in order to provide ideas and theoretical supports for the subsequent in-depth research on synthesis mechanism and clinical application of the composite material. METHODS:Using"metal organic frameworks,hydrogels,tissue engineering,tissue,bone regeneration,bone,wound"as English and Chinese search terms,we searched Web of Science,PubMed,CNKI,and Wanfang databases.The search period ranged from January 2000 to August 2023.By reading the titles and abstracts,the repetitive studies and unrelated literature of Chinese and English literature were excluded.After the literature quality evaluation,73 articles were included for review. RESULTS AND CONCLUSION:(1)Metal organic frameworks-based hydrogel materials effectively solve the problems of poor mechanical properties,unstable drug release and single function of pure hydrogel.(2)Metal organic frameworks enhance the capacity of repair and regeneration by strengthening the cross-linking of hydrogel,the drug delivery capacity of hydrogel and the multifunction of hydrogel.(3)In terms of hard tissue repair,it has shown good repair effects in animal models of diseases such as bone defects,osteoarthritis,and cartilage defects,suggesting potential application prospects in clinical repair.(4)In terms of soft tissue regeneration,it has the capacities of hemostasis,antibacterial,inflammatory state regulation,oxidative stress state regulation,promoting angiogenesis and other functions,effectively improving the microenvironment of various complex wounds and promoting soft tissue regeneration.(5)Although metal organic frameworks-based hydrogels have many excellent properties,they are still in the initial stage and there are some urgent problems to be solved in the process of clinical transformation,such as the cytotoxicity of metal organic frameworks and large-scale synthesis of metal organic frameworks.(6)With further research,metal organic frameworks-based hydrogels have broad application prospects in the field of soft and hard tissue repair.

Research progress on the effect of radiotherapy of nasopharyngeal carcinoma and head and neck cancer on dental hard tissues and oral microbiota / 中华放射肿瘤学杂志

Nasopharyngeal carcinoma and head and neck cancer are the most common malignant tumors in clinical practice. As the most common treatment for nasopharyngeal carcinoma and head and neck cancer, radiotherapy will inevitably cause damage to normal structures such as dental hard tissues and affect the composition of oral microbiota, although it exerts high inhibitory effect against tumor cells. To provide theoretical basis for preventing or reducing the side effects of nasopharyngeal carcinoma and head and neck cancer after radiotherapy and improving the quality of life in patients, related research progress on the effect of radiotherapy of nasopharyngeal carcinoma and head and neck cancer on dental hard tissues and oral microbiota was reviewed.

Clinical management of endo-perio lesion through guided tissue regeneration: a 5 year follow-Up / Manejo clínico de una lesión endo-perio a través de la regeneración tisular guiada: control post-operatorio de 5 años

ABSTRACT: Progressive periodontal disease causes loss of supporting structures of teeth resulting in deep bony defects. In this case a report of 22-year old female patient is being presented with clinical findings of vertical bone loss in two adjacent teeth, on distal surface of 2nd upper right premolar and mesial surface of upper right 1st molar. Root canal treatment, non-surgical periodontal therapy followed by guided tissue regeneration was carried out using decalcified freeze-dried bone allograft (DFDBA) and collagen membrane. Analysis of clinical and radiographic findings showed marked reduction in pocket depth up to 12mm with hard tissue repair on 3-month, 2-year and 5- year follow ups.

RESUMEN: La enfermedad periodontal progresiva provoca la pérdida de las estructuras de soporte de los dientes, lo que resulta en defectos óseos profundos. En este caso clínico se presenta un informe de una paciente de 22 años con pérdida ósea vertical en la superficie distal del segundo premolar superior derecho y en la superficie mesial del primer molar superior derecho. El tratamiento del conducto radicular, la terapia periodontal no quirúrgica seguida de la regeneración tisular guiada se llevó a cabo utilizando aloinjerto óseo liofilizado descalcificado (DFDBA) y membrana de colágeno. El análisis de los hallazgos clínicos y radiográficos mostró una marcada reducción en la profundidad de la bolsa de hasta 12 mm con reparación de tejido duro en seguimientos de 3 meses, 2 años y 5 años.

Primary cilia in hard tissue development and diseases / 医学前沿

Bone and teeth are hard tissues. Hard tissue diseases have a serious effect on human survival and quality of life. Primary cilia are protrusions on the surfaces of cells. As antennas, they are distributed on the membrane surfaces of almost all mammalian cell types and participate in the development of organs and the maintenance of homeostasis. Mutations in cilium-related genes result in a variety of developmental and even lethal diseases. Patients with multiple ciliary gene mutations present overt changes in the skeletal system, suggesting that primary cilia are involved in hard tissue development and reconstruction. Furthermore, primary cilia act as sensors of external stimuli and regulate bone homeostasis. Specifically, substances are trafficked through primary cilia by intraflagellar transport, which affects key signaling pathways during hard tissue development. In this review, we summarize the roles of primary cilia in long bone development and remodeling from two perspectives: primary cilia signaling and sensory mechanisms. In addition, the cilium-related diseases of hard tissue and the manifestations of mutant cilia in the skeleton and teeth are described. We believe that all the findings will help with the intervention and treatment of related hard tissue genetic diseases.

Research progress on Er: YAG lasers applied for tooth bleaching / 口腔疾病防治

@#Er: YAG laser bleaching is a new tooth bleaching method compared with traditional bleaching technology. The Er: YAG laser significantly improves the bleaching efficiency, has the advantages of high safety, short treatment time and excellent bleaching effect and is widely used in clinical operations. This paper summarizes the working principle and bleaching characteristics of Er: YAG laser bleaching technology and its effect on tooth structure. The existing literature suggests that the high absorption of water and hydroxyapatite by the Er: YAG laser makes it work well on water-bearing tissues and dental tissues. When it is absorbed by the bleaching agent on the tooth surface, it accelerates the catalytic oxidation-reduction reaction and selectively acts on the pigment particles deposited on the tooth, thereby achieving the effect of tooth bleaching. Er: YAG laser bleaching can be applied to most discolored teeth. The bleaching process is rapid and effective. During the bleaching process, for the dental pulp tissue, the temperature of the pulp cavity is lower than the critical value of 5.6 ℃, causing no pathological damage to the dental pulp tissue. For the hard tissues of the teeth, laser irradiation will cause changes in the chemical composition of calcium and phosphorus. The enamel presents a unique lava-like shape, and the bonding strength of the tooth increases after bleaching. Compared with other lasers, the Er: YAG laser has a wavelength close to the peak of water, and adding other ingredients to the bleaching agent is not required. Almost all the energy is used for the bleaching agent, with no damage to the surrounding tissues.

Advances in biomimetic modification of materials for oromaxillofacial bone regeneration and dental implant / 华西口腔医学杂志

Oromaxillofacial hard tissue defects is still a difficult problem in clinical treatment. Regeneration of oromaxillofacial hard tissue based on tissue engineering technology has a good clinical application prospect. The functional modification of scaffolds is one of key factors that influence the outcome of tissue regeneration. The biomimetic design of biomaterials through simulating the natural structure and composition of oromaxillofacial hard tissue has gradually become a research hotspot due to its advantages of simplicity and efficiency. In this article, the biomimetic modification of biomaterials for oromaxillofacial hard tissue regeneration is reviewed, expecting to provide a new idea for the treatment of oromaxillofacial hard tissue defect.