An Experiment On The Micro Leakage Effect Of Three Inlay Materials Resin, Glass Ceramic And Pure Titanium With CAD/CAM Technology

Objective: In this research, three kinds of cutting materials: Resin, Glass ceramic and Pure titanium were selected. Computer aided design/computer aided manufacturing(CAD/CAM) combined with chairside economical restorations esthetic ceramics(CEREC) AC method was employed to make inlay for repairing vitro molar type I hole. After temperature cycle experiment, the micro leakage and adaptation between inlay and tooth body of the 3 groups had been measured by dye penetration, stereomicroscope and SEM. The aim is to explore the effect of CAD/CAM technology in inlay restoration and three cutting materials influence on the percolation of the edge of the inlay, to explore the degree of micro leakage differences between non-metallic materials and metal inlay, and further to provide experimental data for the clinical application of CAD/CAM inlay restoration technology and the selection of cutting inlay materials.Methods: 1 The specimen selection Selected thirty recently extracted complete health human normal Premolar teeth, cleaned, placed in saline and stored at 4 ℃. 2 Experimental groups: The extracted teeth were randomly divided into three groups, with ten teeth in each group. Group A: Resin inlay group; Group B: Glass ceramic inlay group; Group C: Pure titanium inlay group. 3 Experimental methods: 3.1 Teeth preparation Class I holes(depth 2 mm) were maked according to the CAD/CAM inlay restoration principles, requested 6-10 o open thought wall(straight, smooth without down concave, dotted line angle clear obtuse), and then fixed vitro teeth in super hard gypsum column model of full teeth. 3.2 Inlay repair operation Group A: CAD/CAM CEREC AC were used to scan, design and cut the final resin inlay. Etch by 30% phosphoric acid for 20 seconds, wash 10 seconds, dry, smear binder, uniform coating, blowing 5 seconds, coating resin adhesive again. Meanwhile, smear binder on the surface of resin inlay, put in cavity, shiatsu fixed 20 seconds, remove excess adhesive, light for 20 seconds, grind and polish. Group B: Making glass ceramic inlay, making porcelain inlay surface treatment with hydrofluoric acid and silane coupling agent. The making and bonding repair steps the same as group A. Group C: Making pure titanium inlay. The making and bonding repair steps the same as group A. 3.3 Psychro-thermal cycles experiments Three groups restored teeth were placed in artificial saliva(37℃) for 24 hours, then placed in circulating water bath(5-55℃) for 2000 loops alternately. 3.4 Dyeing Take out the experimental teeth, dry at temperature, wax-embedded samples closed apical hole.And backfill at 1mm away from the edge of layer 2 applied nail polish, dry. Add 2% methylene blue solution soak for 72 hours in 36 incubator.℃ 3.5 Cut the teeth Remove the dyed teeth, washed, brushed the surface dye, dry in 36 ℃incubator. The teeth were cutting by carborundum chip, oil cooling, polishing. 3.6 Stereomicroscope observation The micro leakage of the 3 groups had been measured by stereomicroscope.The adaptation between inlay and tooth body wall of the 3 groups had been measured by SEM. 4 Statistical analysis Recorded and analyzed the data through Kruslal-Wallis test by using SPSS13.0 software package. When P < 0.05 for the difference is statistically significant. 3.7 Scanning electrical microscope(SEM) observationResults: 1 Stereomicroscope observation: Three groups of experimental teeth inlay edge micro leakage degree are no more than one level.The dyeing infiltrated and colored efficiency from strong to weak order were glass ceramic inlay group, resin inlay group and pure titanium inlay group. There were significant differences among the three groups.(P<0.05) 2 SEM observation: The adaptation efficiency from strong to weak order were glass ceramic inlay group, resin inlay group and pure titanium inlay group. There were significant differences among the three groups.(P<0.05)Conclusion: 1 The degrees of micro leakage were micro scale in all groups with CAD/CAM technology. The glass ceramic inlay group had the lowest degree of micro leakage, the second was resin inlay group, and pure titanium inlay group was the highest than the other groups. 2 The micro leakage of nonmetallic materials inlay repaired with CAD/CAM technology was superior to metal material inlay.