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@#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.
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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.
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Objective To investigate the morphology and bonding of enamel and dentin conditioned by 35% phosphoric acid and pulse Nd:YAG laser.Methods A total of 52 human premolars were selected,40 of which were divided into four groups randomly: group A [enamel treated with 35% phosphoric acid(Scotchbond,3M) for 30 s];group B [enamel treated with pulse Nd:YAG laser(Evlaser Friendly A4 Italy) for 20 s];group C(dentin treated with 35% phosphoric acid for 15 s);group D(enamel treated with pulse Nd:YAG laser for 15 s).The tensile bond strength(TBS) were determined.Except 4 out of 12 human premolars without any treatment,8 were divided into 4 groups and were treated with the method mentioned above.The surfaces of 12 human premolars were observed under SEM.Results The highest TBS was obtained in group A in comparison with the other 3 groups(P0.05).The smear layer on enamel and dentin could be removed after conditioned by both phosphoric acid and pulse Nd:YAG laser.The honeycomb structures were observed on all enamel but less regularly in lased group.Almost all the orifices of dentinal tubules were open in the acid group and sealed or half-sealed in lased group.Conclusion The pulse Nd:YAG laser did not contribute to bonding of enamel,but could improve the bonding of dentin and seal most of the orifices of dentinal tubules,which reduced the harmful stimulation to the dental pulp.