| Research Abstract |
FOR REMOVABLE PARTIAL DENTURE WORKING BEST,IT IS ESSENTIAL TO MAKE THE DENTURE MOVEMENT AS SMALL AS POSSIBLE.BUT,IF THE ABUTMENT TOOTH IS LOADED HEAVILY FOR THE PURPOSE OF MAKING THE DENTURE MOVEMENT SMALLER,IT WOULD BE PUT THE CART BEFORE THE HORSE.THIS IS BECAUSE IT IS NEEDED TO RESTRAIN THE DENTURE MOVEMENT WITHIN THE LIMITS OF NOT DAMAGING THE ABUTMENT TOOTH.THE PURPOSE OF THIS STUDY WAS TO ANALYZE THE FORCE DISTRIBUTION OF ABUTMENT TOOTH IN CASE OF USING SEVERAL RETAINERS,ESPECIALLY INTRA RADICULAR ATTACHMENTS.
FIRST,WE MADE ROOT TOOTH MODEL OF LOWER CANINE,INCLUDING ALVEOLAR BONE,PERIODONTAL MEMBRANE AND GINGIVA.NEXT,WE CHOSE 4 DIFFERENT KINDS OF ROOT RETAINERS,HI-COREX SUPER,BONA 604A,BATTESTI AND PO-ANCHOR.IN ADDITION,WE FIXED RESIN DENTURE BASE INCLUDING ARTIFICIAL TOOTH ON EACH RETAINER.Finally, WE SET THOSE FIGURES ON THE X-Y COORDINATES.THE COMPUTER SOFT FOR ANALYZING FORCE DISTRIBUTION IS FINAS AND FEMAP FOR CUTTING THE MESH.AS FOR OBJECT CONSTANT (THE YANG AND POISSON RATIO) AND EXPERIMENTAL CONDITION,THE SAME FIGURES AND CONDITION AS THE LAST YEAR WERE USED BASED ON THE FACT THAT THE EXPERIMENTAL SITE OF FORCE CONCENTRATION WERE COINCIDED WITH THE SITE OF ALVEOLAR BONE RESORPTION OF REAL X-RAY PHOTOGRAPH.THE MAGNITUDE OF FORCE APPLIED WAS 2-5N.AND DIRECTION WAS FROM THE LABIAL TO LINGUAL IN CONSIDERATION OF THE MODEL BEING LOWER CANINE.THE RESULTS WERE AS FOLLOWS ;
1.THE FORCE MAGNITUDE AND DISTRIBUTION AROUND ABUTMENT TOOTH DIFFERED FROM EACH RETA5NER.THIS MAY BE BECAUSE THE DIFFERENCE OF THE MATERIAL AND/OR THE POSITION OF MALE AND FEMALE LOCKING AND/OR RETENTION EXERTING MECHANISM.
2.THE FORCE DISTRIBUTION OF THE HI-COREX SUPER AROUND TOOTH OBVIOUSLY DIFFERED FROM OTHER 3 ATTACHMENTS.THIS IS BECAUSE THE HI-COREX APPLIES MAGNETIC FORCE AS RETENTIVE FORCE.THEREFORE,IT IS NECESSARY TO ANALYZE MAGNETIC FIELD OF MAGNETIC ATTACHMENT FOR THE PURPOSE OF EXAMINING FORCE DISTRIBUTION IN DETAIL.
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