堆载引起桥梁墩台与基础的偏移及防治技术研究

1、Accuracy of three corrective techniques for implant bar fabrication Giancarlo G. RomeroAbstractStatement of the problem. component passivity . Passive , , .Purpose. bar bar passive 3 post-casting .Material and method.3.8/4.5 HL PME 30 Hader bar . M2001ARS toolmaker microscope bar y . , , . indexing

2、.(1) indexing soldering.(2) MedArc M-2 EDM machine 2 electrical discharge machining.(3) 3 . 0.05 1-way ANOVA Turkey-Kramer test .Result. gap 1 192µm, 2 190, 3 198. 1(15µm) 2(72µm) 2 3(7.5µm) gap . 1 3 .Conclusion.Electro discharge machining group 7.5µm gap passive fit (10

3、81;m) . 2 , , passive fit . electro discharge machining .Fixtures implant-retained, removable denture restorations 2 . resilient attachment . fixture non-resilient attachment . bar-retained . 12-13mm . protocol . fixture passive fit . . passive , . . fixture passive fit . fixture abutment 10µm

4、. bar . error , , , , . . error post-casting . bar soldering , , electro discharge machining (EDM). indexing material, soldering investing material , , component . bar fixture non-passive fit 3 post-casting . soldering, , EDM . 3 bar gold coping gap .Material and methodsMaster and working model fabr

5、ication master model 30 bar . master model 2 .(3.8/4.5 HL PME transmucosal ABUTMENT,6mm Steri-oss). . 18mm .(1) Fig. 1. Metal master model with titanium implant abutments. 24 30 . Polyether polyether adhesive . 2 guide pin impression coping open tray . type 4 30 2 . bar master model verification jig

6、 .(2)Fig. 2. Verification jig on master (A) and working (B) models.Bar fabrication gold alloy bar 15N.cm . 18mm 3.8mm Hader bar pattern pattern resin bar coping . pattern matrix . bar type 4 gold alloy 2 cycle . 2 1 1 11 427 30 2 1 11 704 75 . Gold cylinder , air chisel hydrofluoric acid substitute

7、solution . Air abrasion polishing . 30 bar .Fig. 3. Graphic illustration of gap measurement at interface between implant bar assembly and implant abutment. Inset is M2001ARS Toolmaker microscope.Initial measurements bar coping M2001ARS Toolmaker microscope . bar 15N.cm . master cast abutment , , “A”

8、 . gold coping “B” . A B 90 filar reticle Drum micrometer linear scale gap distance . (3) gap .(3) , post-casting modification technique 3 .Cast-to technique(1)Cast-to technique bar 0.45mm disk gold cylinder 5mm . indexing undercut milling.(4) Bar segment Hader clip 15N.cm . GC pattern resin . 12mm,

9、 10gauge junction . .Fig. 4. Bar cut (A) and edges undercut (B) before correction by cast-to technique.Soldering technique(2)Soldering bar 1 indexing. Soldering bar undercut milling polishing . soldering block matrix .(5)Fig. 5. Bar cut (A) and indexed for correction (B) by cut-and-solder technique.

10、 block 1 17 649 20 . borax flux . 6mm solder strip gas-air torch . 1,2 .Electrical discharge machining(3)EDM 2 replica mounting . 10 transfer jig . catalyst cyanoacrylate cement replica . (6) matrix . bar . Fig. 6. A, Verification jig fabricated on master model. B, Transfer jig with copper abutment

11、analogs and wires attached before pouring EDM working model.Fig. 7. A, Working model ready for EDM process. B, Bar (workpiece) undergoing EDM process. 2-dimensional EDM machine bar electrical discharge machinig . machine setting .25-40 microsecond(feed rate), 30-60volt(gap voltage), 1-3 amperes(powe

12、r level), setting. Gap voltage meter ampere meter . reading cut reading cut . EDM criterion setting reading spark . cycle bar .(7)3 . gap dimension data 1-way analysis of variance . 0.05 Turkey-Kramer .Result gap . gap M2001ARS Toolmaker microscope , , gap . Fig. 8. Graphic representation of as-cast

13、 and corrected means for 3 tested groups. gap . gap 7.5µm.(3) 1 gap 15µm . bar soldering 2 72µm. 1 8 . 1-way ANOVA 3 . P<0.05 . Turkey-Kramer test 12, 23 . 1 3 .1 cast-to technique . cast-to technique gold coping . 3 10 7 . misalignment . 2 2 .Table I. Means and standard deviations

14、 for the 3 groups before and after technique GroupStatusNo. of barsMean (µm)SD (µm)Cast-toAs-cast1019270SolderAs-cast1019070EDMAs-cast1019878Cast-toModified101512SolderModified107215EDMModified107.53.3EDM = Electrical discharge machining.Discussion bar , , bar assembly wax-up, , . nonpassi

15、ve fit . 30 initial gap . , .Cast-to technique soldering . White , .(super-heated) super-heat . super-heat . soldering torch bar joint . soldering .Bar assembly index 1 2 error . . index assembly coping portion .Fit technique post-casting correction . Rangert Jemt criteria passive 10µm gap . ca

16、st-to technique soldering (passive) . cast-to technique 50% 10µm , soldering . soldering . Soldering , , , , , . undercut .EDM gap 7.5µm. 3 . . . cutting electrode workpiece . gap distance error EDM , transfer jig , . EDM workpiece . machining process . EDM . 3 cut . EDM cycle . machining cycle “no wear” . Linehan . error EDM .EDM . 1 heat treatment . Tan heat cycle . EDM . EDM bar assembly .EDM . , indexing coping . 3 .Conclusion