Different Methods Of Repairing Denture-Extension Absence By Using Biomechanical Study And Clinical Research

Objective:Distal-extension absence to explore different retention repair methods advantages and disadvantages of abutment stress distribution and clinical should be the same,for clinical distal-extension absence to provide theoretical evidence for the selection of repair methods,improve the quality of clinical distal-extension absence to repair.Methods:For patients with unilateral distal-extension absence,this article selects the original CT for adult mandibular cone beam CT,through Materialise Mimics 17.0 software to complete the preliminary 3 d model reconstruction,through the software 3-Matic STL 10.2 and Geomagic Studio 2013 to complete the three dimensional finite element model refinement,using software Hyper Works 14.0 and ABAQUS finite element modeling simulation processing 6.1.4.This paper respectively established with the software contains the abutment and the periodontal ligament,alveolar ridge and denture five of the denture restoration approach(planting denture,natural teeth-fully mixed fixed bridge,sleeve crown denture,attachment denture,removable partial denturerepair distal-extension absence three dimensional finite element simulation model.The contact unit is used in the area of the teeth between the teeth and the other parts are adopted by the second order tetrahedral unit.Biomechanics of three-dimensional finite element analysis method is applied to determine and compare the analysis of vertical and oblique(cheek,tongue and far to)when loading in the center of the fang surface grinding different retention distal-extension absence and the structure of the denture abutment stress distribution and the peak stress.According to the results of three dimensional finite element analysis to guide clinical distal-extension absence repair,in patients with different retention method in clinical(planting denture,sleeve crown denture,attachment denture,removable partial denture repair distal-extension absence chewing efficiency and patient satisfaction were compared.The object of study for the fellowship at jilin university hospital dental clinic for poor old removable partial denture not comfort,beautiful or chew the result is bad request to make denture patients.Results:1 The abutment stress distribution uniformity: pure planting denture is superior to the sleeve crown denture is better than that of attachment denture is better than that of removable partial denture is superior to the fully mixed with natural tooth fixed bridge.2.The abutment stress peak value: sleeve crown dentures(2.23 MPa)< attachment dentures(2.65 MPa)< removable partial denture(4.16 MPa)< planting denture(41.54 MPa)< fully mixed with natural tooth fixed bridge(50.05 MPa)3.The maximum stress concentration: the implant is concentrated in the cervical side of the tongue.Natural dentition-a mixture of fixed bridge natural teeth and implants is concentrated in the distal side of the tongue.The two base teeth of the sleeve crown are concentrated in the far middle of the neck;The teeth of the attachment are concentrated in the far middle of the tooth,and the base teeth are concentrated in the far side of the neck.The base teeth are concentrated in the far middle of the teeth,and the base teeth are concentrated in the far side of the neck.4.The relationship between the loading direction and the stress: in all the fixed-position methods,the vertical direction load stress peak is less than inclined to load,and is more uniform.5.The top teeth of the socket,the adhesion and the removable partial denture show that the stress peaks are less than the base teeth and the stress distribution is more uniform.6.Masticatory efficiency comparison: planting denture,attachment denture,sleeve crown denture masticatory efficiency of no significant difference,removable partial denture masticatory efficiency and minimum compared with other kinds of three methods of retention havesignificant differences.Conclusion:1.In the case of the absence of the free end of the tooth area,it is better to repair the clinical effect than the other fixation method by simply planting the prosodontia.2.The ball cap type sleeve crown denture on abutment stress buffering effect is best,more suitable for poor fang zhou conditions and inappropriate or intolerance fully distal-extension absence repair of patients.3.Buckle type attachment denture can be better to reduce stress,abutment teeth were suitable for base fang zhou healthier,and inappropriate or intolerance fully,or abutment anatomic conditions is not appropriate to do the free end of the sleeve crown denture patients lack of repair.4.Well-designed distal-extension absence and the removable partial denture can also achieve good masticatory efficiency,more suitable cannot tolerate or unwilling to accept any other kind of repair and low requirements for beauty and comfort or limited by economic conditions cannot choose other type of repair distal-extension absence in patients with repair.5.Natural teeth-fully mixed fixed bridge foundation and uneven distribution of tooth stress peak value,the largest stress differences ofnatural teeth and planting denture could affect the repair long-term effect,do not recommend using this type of repair methods to repair clinical distal-extension absence.