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ABSTRACT Introduction: In clinical practice, submerged roots are found with high frequency, and their presence can change the planning of dental movements and implant placement. Objectives: To provide explanations of possible developments in the area involved, according to the evolutionary stage of the process, at the time of diagnosis. Discussion: After atrophy of the periodontal ligament and epithelial remnants of Malassez, ankylosis of the bone with the submerged root occurs, and initiates a process of replacement resorption. Until this process reaches the most advanced stage, this area represents an increased "bone" density, and if some care is not taken, this can generate resorption problems in the tooth to be moved. Whereas implants can be placed, despite the presence of the submerged root, irrespective of the stage of evolution. Conclusion: It is natural for the onset of alveolodental ankylosis and tooth replacement resorption to occur in submerged roots, and its stage of evolution will be decisive in the approach to be adopted in clinical planning.
RESUMO Introdução: A frequência, na prática clínica, das raízes submersas é elevada, e sua presença pode modificar o planejamento de movimentações osteodentárias e da instalação de implantes. Objetivo: Apresentar as explicações das possíveis evoluções na área envolvida, de acordo com o estágio evolutivo do processo, no momento do diagnóstico. Discussão: Depois da atrofia do ligamento periodontal e dos restos epiteliais de Malassez, o osso anquilosa-se com a raiz submersa, e se inicia a reabsorção por substituição. Até se chegar ao estágio mais avançado, essa área representa uma densidade "óssea" aumentada, o que pode gerar problemas reabsortivos no dente a ser movimentado, caso alguns cuidados não sejam tomados. Por outro lado, os implantes podem ser aplicados, apesar da presença da raiz submersa, independentemente da fase evolutiva. Conclusão: É natural que, em raízes submersas, se instale a anquilose alveolodentária e a reabsorção dentária por substituição, e o seu estágio evolutivo será determinante na conduta a ser adotada no planejamento clínico.
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Objective To investigate the clinical effect of minimally invasive extraction of anterior tooth residual root after root separation.Methods A total of 400 patients receivinganterior tooth residual root extraction were collected in the clinic of oral and maxillofacial surgery department between January 2015 and December 2016.The patients were divided into a control group and a study group according to their sequence to see the doctor,with an odd for the study group and an even for the control group.In the study group,residual roots were separated mesiodistally by high speed turbine before using minimally invasive extraction tool;while in the control group residual roots were extracted only using minimally invasive extraction tool.The surgical duration,postoperative damage rate of the lip side plate,degree of pain and patient satisfaction in the two groups were analyzed.Results The surgical duration was shorter in the study group compared with the control group (P < 0.05).The postoperative damage rate of the lip side plate and the degree of pain were lower,while patient satisfaction was higher in the study group than in the control group (P < 0.05).Conclusions The postoperative damage rate of the lip side plate is significantly lower in minimally invasive extraction of anterior tooth residual root after root separation.Smaller trauma is conducive to the implant afterwards.Root separation in minimally invasive extraction of anterior tooth residual root is valuable for clinical application.
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20 first mandibular premolars were randomly divided into 2 groups(n =10).The teeth in experimental group were treated by fi-ber main post in combination with auxiliary pile,in control group by single fiber main post,and then were restored by metal crown.They were fixed in universal testing machine.The fracture load(N)of experimental and control group was (846.50 ±40.33)and (437.90 ±41.15) respectively(P <0.01).
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Objective To observe the effects of root canal preparation for post-core immediately after root canal obtu-ration. Methods A total of 106 cases of mutilated coronal tooth structure, after endodontic therapy, indicated for post-core and crown, collected from dental outpatients in our hospital during 1st Oct 2011-30th Sep 2013, were randomly divided into the control group and the experimental group. The experimental group were prepared for post space 7 days after root obturation, and then the teeth were prepared for retention of crowns; while in control group, post space was made 7 days after obturation. The two groups were observed in intervals of every half a year after treatment to examine the integrity, masticatory function and retention. Meteyards were established to evaluate its clinical effects. Results During follow-up visiting patients half a year to 2 years, in control group, there was 1 patient with splitting along buc-clingual direction and 4 patients with fracture of coronal structure before preparation;after restoration there were 3 pa-tients with periodontitis in the 1st year, 4 patients with periodical periodontitis, and 1 patient with loosening of post in the 2nd year, all of which were failure cases. In experimental group, before preparation there were no fracture case;after restoration there were 2 patients with periodical periodontitis in the 2nd year and 1 patient with periodontitis in 1 year. All the 3 cases counted as failure cases. The total successful rate in control group was 76.36%, and 94.12% in experimental group. The successful rate in the experimental group was significantly higher than the control group(P<0.05). Conclusion Root canal preparation for post-core immediately after obturation is more successful than the usual way with better apical sealing,less complication and frequency of teeth fracture .
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The extracted human maxillary central incisors were endodontically treated and restored with glass-fiber post. Then they were randomly divided into four groups and tested. Results showed that groups with ferrule more than 2 mm had higher fracture resistence than others.
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Objective:To presents a new way of constructing post crowns for the anterior maxillary teeth which had the subginginval crown fracture more than 3 mm.To discusse the difficulties in the restoration of the subgingival residual roots and residual crowns of anterior maxillary teeth,and to explore the principles of the new restoration by the casting post-core and the porcelain fused mental crowns with wings. Methods: 23 patients(26 teeth) which had crown fracture more than 3 mm under the gingival were enrolled in this study.After those residual roots and crowns were endodontically treated following the conventional root canal therapy,the casting post-core and the porcelain fused mental crowns with wings were applied to reconstructing those missing crowns. Results: After 3 months to 5 years clinic observation,restored crowns were still stable with good retention and fracture resistance. Conclusion: Those residual roots and crowns can be preserved by this innovative way and can also acquire satisfactory effects in esthetics and functions.
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Discussed how to use column split-core crown to repair the indications of the residual crown and root of posterior teeth,as well as its clinical results.Root canal treatment of the residual root,repaired the residual crown and root of posterior teeth with column split-core crown,and then used it as a fixed bridge abutment.No loose,no pain,no loss and jaw bite was in a good recovery compare to the standard after 1-2 years follow-up.It is a good method to use column split-core crown to repair the residual crown and root of posterior teeth under certain conditions.
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In order to explore the clinical effect of the glass fiber-reinforced composite resin post core for severe defect restoration of front teeth,sixty-two teeth were restored for forty-one patients with severe defect restoration of front teeth by glass fiber-reinforced composite resin post core plus alumina all-ceramic crown.Through 0.6-2.0 years follow up,all the prosthesis worked very well without breaking or falling off,no gum coloring except two posts fell off after the restoration at sixth month.The patients satisfied with the restoration.
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Based on the properties of the zirconia all-ceramic material,this report presented a clinical application with the zirconia all-ceramic crown/bridge for restoration of multiple residual roots and crowns.
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The residual crown and root has very important physiological significances,but there are many problems in the clinical treatment,such as overtreatment and defensive treatment,etc.This article analyze the background and causes of these problems,and provids some corresponding ways to solve them.
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Objiect:To generate three-dimension finite element mode of the first maxillary molar residual root restored with post-core crown,to analyse the stress of post-core crown of posterion tooth.Methods:Models were generate by CT scan,Mimics software and Abaqus software. Result:The three-dimensional models of the first maxillary molar residual root restored with post-core crown were generated. Conclusion:The generated three-dimensional models of the first maxillary molar residual root restored with post-core crown.were highly similar in geometry and mechanics to the real instance,which could be used to study stress of posterion tooth residual root restored with post-core crown
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Objective To investigate the stress distribution in various tooth heights of ferrule effect in post crown,and to evaluate the biomechanical mechanism in post crown.Methods The three-dimensional finite element entity grid model was constructed,which was a maxillary central incisor restored with post and porcelain fused to metal crown (PFM crown).By imitating the various tooth heights under static loading,the dentin stress was analyzed.Results The stress distribution had an increasing tendency from tooth cervix to root,but it could be decreased by ferrule structures and the decrease degree accorded with the region and height of ferrule.The ferrule effect of the wrapping 1 cm coronal tooth could decrease the stress of the tooth cervix obviously but 2 cm decreased a little.Conclusion The crown wrapping 1 cm coronal can produce ferrule effect obviously and protect the tooth.We can choose to use crown wrapping 2 cm coronal to care the tooth condition.