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The Research of Welding Condition in Bar Attachment Applied to Implant-supported Overdenture by Pulsed Nd:YAG Laser

Author: CuiGuang
Tutor: SongYingLiang
School: Fourth Military Medical University
Course: Clinical Stomatology
Keywords: Laser welding Mechanical behavior AutoCAD
CLC: R783.6
Type: Master's thesis
Year: 2008
Downloads: 92
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Abstract

As the the planting technology matures, more and more dentition missing patient selection implant-supported overdenture attachment asanas retention (rod card, sleeve, cap, magnetic attachment), a good solution clinical conventional full denture retention problem of poor stability, improve the quality of life of edentulous patients. However, the original planting lever cassette cover denture use titanium lap and Co-Cr alloy whole casting connecting rod, in precision such limitations, the dental laser welding technology to make up for this the lack of satisfactory results obtained in the production of planting overdenture bar attachment and rod attachment soon titanium rod and bridge up lap welding surface fracture, but also in clinical applications. At home and abroad has not been for laser welding fabrication of titanium growing rod attachment to the cause of the fracture and welding production conditions? Still need further study. Research purposes in the first part of this research by simulating the ITI implant system rod attachment specifications; four groups of different Nd: YAG laser welding parameters welding production 30 titanium specimen mechanical properties evaluation, and scanning electron microscopy, to explore the welding parameters on the welding The surface mechanical properties of looking welding production parameters to meet the requirements of clinical applications. Based on this, the second part of the study of 18 using the same welding parameters welding system 2 group the different rod ring Connetor titanium specimen by a mechanical performance evaluation, and scanning electron microscopy, to explore a the lever ring of forms on the the welding surface mechanical properties of the rod-card attachment. In the third part of the study will examine the first and second part recorded by scanning electron microscopy image of the welding surface image graphics conversion later import AutoCAD workstations, highly accurate measurement of the depth of the welding surface welding and welding area, explore the welding parameters, rod ring interface morphology on the relationship between the depth of the weld, the welding area and the depth of the weld, the welding area and the mechanical properties of the welded surface of the three, through the study to provide the experimental basis for the production and clinical application of laser welding rod attachment for planting. Research methods and results: The first part: Analog ITI implant system lever card specifications clinical use, the use of CNC machine tools to a single piece of TA2 titanium plate cut into 40 mm × 3 mm × 2 mm titanium rod. Polished titanium rod ends were randomly divided into five groups, four groups for the experimental group (experimental group ABCD) for the control group, each set of sample number 6. Specimen before welding washed with acetone 15min, and then distilled water ultrasonic cleaning 10min after drying to be welded specimen coaxial seamless holder in the fixture of the experiment special fixing screws locked DESKTOP dental dedicated laser welding machine with four different sets of welding parameters welding production specimen. The various welding overlap rate is 2/3, single pulse, double-sided welding. All welding operations are the same mechanic operation. After the production of the specimen, observation and mechanical testing of the specimen by the naked eye and universal testing machine, using the scanning electron microscope specimen weld fracture, record the scanned picture, and compared with the control group. The results obtained using the SPSS13.0 statistical software for statistical analysis. The results showed that: (1) showed a silver-white of the weld, the weld surface smooth, no coloring, no cracks, weld area slightly sunken. (2) The test specimen cleavage site in the weld zone, the base material of the control group, were made in the central part of the fracture. Elongation of the experimental group and the base material group decreased brittleness of the weld zone can be seen to increase significantly. There was significant difference (P lt; 0.05); B, C, D experimental group tensile strength with the base material close to the tensile strength of the base material of the weld zone of the experimental group A and B, C, D experimental group, no statistical difference (P gt; 0.05) Mechanical properties test results of the control group to meet GB/713810-1997 national standards, reached clinical use standard. (3) in the scanning electron microscope at low magnification to observe the fracture were not full penetration welding area was ringed, no obvious pores welding defects, welding area edge wavy, no significant necking; high magnification The honeycomb structure of the welding group compared with the control group was shallow, no significant difference between the experimental group. Experimental results show that when the laser welding machine working voltage of 305-330v, the pulse width is 10ms or 12ms, solder diameter of 1mm, the tensile strength of the laser welding zone of the rod attached to the body and the base material close to meet the requirements of clinical use . Part II: specifications processing of analog ITI implant system 6mm x 4mm x 1mm titanium up lap specimen, using the first part of the experiment with the same batch of 40 mm × 3 mm × 2 mm titanium rod divided into two groups, a total of 18 in the experimental Groups lever ring interface is the curved surface of the control group for the plane; the specimen before soldering 15min, then washed with acetone and distilled water, ultrasonic cleaning 10min After drying, the two test pieces to be welded clamping lever in a special fixture, measured with vernier caliper control group The ring gap and recorded. DESKTOP dental laser welding machines use the same welding parameters welding system, the parameters in line with the first part of the test to determine the range of welding parameters. The various welding overlap rate is 2/3, single pulse, double-sided welding. All welding operations are the same mechanic operation. After the production of the specimen, observation and mechanical testing of the specimen by the naked eye and universal testing machine, using the scanning electron microscope specimen weld fracture, record the scanned picture. The results obtained using the statistical software SPSS13.0. The results showed that: (1) Facing the interface specimen welding gap is less than 0.5 mm. (2) groups showed a silver-white weld, the weld surface smooth, no coloring, no cracks, weld zone slightly sunken. (3) the mechanical properties of the test results: two sets of specimen fracture site in the welding area, two groups of elongation, tensile strength was no significant difference (P GT; 0.05). (4) Scanning electron microscopy showed: low magnification fracture were not fully penetration welding area was ringed and found no obvious weld defects such as porosity, wavy edge of the weld area, no significant necking. Experimental results show that: When welding pitch lt; 0.5mm and welding parameters (the welding parameters to meet: Working voltage between 305-330V, pulse width of 10ms or 12ms, solder joint diameter 1mm), different rod ring interface morphology the mechanical properties of the welded surface had no significant effect. Part III: The first part, the second part of the scanning electron microscope image is recorded CorelDRAW software to capture the image edge graphics into AutoCAD workstations were used to measure the maximum depth of the surface of each weld and welding area, and calculate the average use SPSS13. 0 statistical software for statistical analysis. The results show that: (1) the first part of the mechanical performance parameters and other experimental group A experimental group statistical difference in the mean of the maximum depth of welding and welding area with other experimental group there was significant difference (P lt; 0.05), The above values ??are in the other experimental groups no significant difference (P gt; 0.05) (2) The second part of the experimental group and the control group no significant difference (P gt; 0.05) on the mean of the maximum depth of welding and welding area. (3) The first part of the tensile load, welding depth and welding area of ??the relations between the curve shows the depth of welding and welding area there are approximate ratio between the relationship with the different welding parameters, welding area and tensile strength between positive correlation between the second part of the tensile load, welding depth and welding area of ??the relations between the curves show the same welding parameters, welding depth and welding area has maintained an approximate ratio between the two sets of specimens in the form of different rod ring of welding the depth of the welding area found no significant effects occur. Conclusions: (1) Laser welding machine working voltage between 305-330v, the pulse width is 10ms or 12ms, solder diameter of 1mm, the tensile strength of the base material of the the the planting rod attachment laser welding area close to meet clinical application requirements. (2) When the rod attached to the body, welding of titanium rod and then circle spacing is less than 0.5mm, and the welding parameters, the same (welding parameters satisfy: Operating voltage at between 305-330v, the pulse width is 10ms or 12ms, the solder diameter 1mm), the different rod ring Connetor no significant effect on the mechanical properties of the welded surface. (3) the depth of the welding surface welding and the welding area approximate proportion relationship that changes with the change of the welding parameters, welding depth, positive correlation exists between the welding area and the tensile strength. (4) For the laser welding rod attached to the body, incomplete welding of the weld zone does not affect the normal application.

The Research of Welding Condition in Bar Attachment Applied to Implant-supported Overdenture by Pulsed Nd:YAG Laser

Abstract

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