The Clinical Application Of Ball-cap Attachment Overdentures

Dentition defect is one of the most common diseases in the prosthodontics. From only one tooth lost in the detition to even one root remained in the detition can both called dentition defects. The common cure methods include fixed partial dentures,removable partial dentures , fixed-removable dentures and so on.When there are several teeth remained in the oral only roots especially,we may design traditional removable partial dentures for patients. But the clasps of the partial dentures may produce more lateral force to the abutments that may induce secondary caries or loosening of the abutments easily.Once patients step into edentulous ,if the conditions of the alveolar are poor,the retention,stability, Masticatory efficiency of the complete dentures will be lower. The clinical effects of the complete denture are not satisfactory. How to inprove the effect of the dentures,in the same time delay the time of being edentulous become more important in the prosthodontics.Overdentures are the removable dentures or complete dentures that there are roots or crown supporting the dentures under the base. It can be used when the remaining teeth are few and the periodontal conditions of abutments are disadvantaged in the oral.The reservation of the roots benefits the height of alveolar and periodontal proprioceptor improve the masticatory efficiency.The vertical force of the abutments can improve its periodontal conditions that extends the life of the abutments .In other respects, the change of crown-root ratio reduces lateral force and torque of the abutments that benefits the health of the roots and the alveolar. Ball-cap attachment is the simplest of all kinds of attachments.It includes spherical metal Yang-type structure and resilient plastic Cap Yin-type structure. Ball-cap attachment used in the overdenture improves the supporting,retention,stability of the denture. Ball-cap attachment allows the denture to have mobility in Horizontal direction and Vertical direction which benefit stress-buffering and distribution. Ball-cap attachment can be used,in many conditions even if there is only one root remained because of its small size, simple structure and the low request of abutments. Ball-cap attachment overdenture has enough rentention .Its advantages combine both the advantages of the attachment and overdenture:remains the roots so that reduce the resorption of alveolar and improve the supporting ,retention,stability of the denture;remains Periodontal ligament receptors which have fine regulation of force;the change of Crown-root ratio reduces Lateral force and torqueo of the abutments that benefits the health of the roots and alveolar;the remaining of root can relieve the pain of extract;Ball-cap attachment allows the denture to have mobility in Horizontal direction and Vertical direction benefiting stress-buffering and distribution;Ball-cap attachment is between abutment and base so that it can't be seen in the oral.In this study, twelve Ball-cap attachment overdentures are fabricated for twelve patients with few teeth in the oral.The method is investigating clinical performance for six months from some aspects of subjective feelings ,clinical examination,x-ray examination.The aims of this study are investigating the clinical effects of overdentures retained with ball-cap attachent and the problems in the clinical in order to provide some clinical guidance .After six months follow-up,we found that almost all the patients felt fine retention,more stable,more comfortable ,adaptive,more aesthetics and convenient compared with traditional removable partial dentures.The gingivitis occured in gingival edge of one patient. Inflammation subsided after treating without any other changes. There were no obvious alveolar bone absorption among twenty abutments seeing from x-ray but the periodontal ligament of one of the abutments became wider.The mobilities of all the abutments didn't change obviously. The clinical effects of these overdentures retained with ball-cap are satisfactory .We can include from this study that ball-cap attachment overdentures have great retention , stability , aesthetics .The ball-cap attachments have practically value in clinical appliance patient's mastication. It is proved that ball-cap attachments are effective to improve the function of complete overdentures,worthy to be used widely.It is also suggested that the residual root and loosened tooth should be preserved furthest as possible in clinic.To sum up ,as China's standard of living of the people improve, the consciousness of retaining teeth gradually increases. Patients especially the old want the dentures to have great retention and function. Ball-cap attachment overdentures have great prosthetic effects and they are cheaper,more simple than any other overdentures, worthy to be used widely.