Clinical Research Of Unilateral Distal Extensive Absence With Extracoronal Precision Attachments

The deletion of free end is the common diseases and frequently encountered diseases of the prosthodontics dentistry. The all-important purpose of prosthodontics of the deletion of free end is to restore the masticatory function, the denture should improve the masticatory efficiency as possible, in addition to considering the sufferer's beautiful request. In the case of the deletion of free end, because the posterior teeth undertake the most mastication pressure, there is no nature teeth in the distal that can support the denture, the support form of the removable partial denture is to supports together by the abut-ment and residual alveolar ridges. The abutment provided the re-lative stationary support, but the alveolar ridge mucous membrane have the relative removability, because of the difference of the two organizations, the removability size is not inconformity, the remov-ability of the mucous membrane is far larger than the abutment. It makes the denture revoluted, sinked, and occurring other unsteady phenomenon, affected the masticatory efficiency of the denture directly. Therefore how to improve masticatory efficiency, in premise of guaranteeing the health of the soft hard oral organization, is one of the important topics of the study of the domestic and international prosthodontics dentist. The precision attachment (PA) is a kind of embedding retention apparatus, one part is fixed on the root, the crown or the implant, the other part is chained to the plate or the bridge of the denture, it supply the denture with retention, support and stability. The retention part of the extracoronal attachment is designed out of the abutment crown. Because of the protection of the complete crown, the abutment of the extracoronal retention is not easy to be decayed. Furthermore, it will not produce the lateral force to the abutment when the denture is taken and worn, the retention force of the extracoronal attachment does not depend on the outline of the crown, and the retention force can be easily controlled, the access-orial lingual can prevent the denture from swing and rotation. This clinic research aims at the low masticatory function after using the free end case, chosen 17 cases that have ever used the removable partial denture, but had low masticatory function and requesting to manufacture a new denture, determine the masticatoryfunction of the original denture with light-absorptive method, analyzes its reason, re-manufacture a clasp-type removable partial denture, determine the masticatory function of the denture 1 month later; then manufacture a new attachment denture, determine the masticatory function of the denture 1 month later. Carry on the comparison of the masticatory function to two kinds of prostho-dontics. In the 17 unilateral deletion of free end cases whom complained low masticatory function, analyzes its reason, 4 cases is because of bad plate fitness; 3 cases is because of insufficiency with plate extension; 1 case is because the abutment is not appropriate; 1 case is because there is no indirect retainer; 4 cases is because of bad alveolar ridge appearance; 2 cases is because of occlusal rest posi-tion designed absurdly; 2 cases is because of the sufferer's mental agent. After the new attachment denture adhered, observed with 6~12 months, there are 16 cases claimed with improved masticatory fun-ction in evidence. Examine these cases, the denture is with good retention and stability, no turnup swing or sinkage is found; there is1 case claimed no evident improvement, Examine the case, we found that the alveolar ridge is low, after repair the denture with a indirect retainer, the sufferer feels better. All the sufferer feel the attach-ment denture beautiful, comfortable, with little foreign body sensation, clear pronunciation, not impacting food, sanitary, durable and easy to take it out and wear on. Adopting the method of self-control, the t test, comparing the masticatory function between the original clasp removable partial denture and the re-manufacture clasp removable partial denture, shows that the difference has distinct significance between them, it reveals that the masticatory function of the re-manufacture clasp removable partial denture is higher than the original clasp remov-able partial denture (P<0.01). The t test, comparing the masticatory function between the extra-coronal precision attachment denture and the re-manufacture clasp removable partial denture, shows that the difference has distinct significance between them, it reveals that the masticatory function of the extracoronal precision attachment denture is higher than the re-manufacture clasp removable partial denture (P<0.01).Through the clinic research, we get the conclusion that if the sufferer's oral condition is well, a re-manufacture clasp removable partial denture can basically satisfy the demand of sufferer's masti-catory efficiency. The retention, stability, support of the extra-coronal precision attachment denture is effective, it's comfort and beauty, the sufferer will accept easily. Under the condition that the oral condition be permitted, should be the prior choice of prostho-dontics to the deletion of free end. The masticatory function of the extracoronal precision attachment denture is higher than the clasp-type removable partial denture in evidence. The stress force distri-bution of the periodontium is even with extracoronal precision attachment, it will benefit the health of the periodontium. The indi-cation should be controlled strictly, when repair the deletion of free end with extracoronal attachment denture. Higher technology level is required to dentists and technicians. The manufacture of the attachment denture involves casting and baking porcelain technology, sometimes need to involves other aspects, such as implantation, magnetic body and the laser welding and etc., the technology have high request and is not easily control-...