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Laboratory Observation of S.mutans Adhesion on Two Non-noble Metal Materials

Author: TianGuoBing
Tutor: ZhangBingSheng；LiJinLu
School: Shanxi Medical
Course: Clinical Stomatology
Keywords: Nickel-chromium alloy Cobalt-chromium alloy Surface roughness Adhesion Microecology
CLC: R783
Type: Master's thesis
Year: 2010
Downloads: 76
Quote: 1
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Abstract

Excessive accumulation of plaque in the oral cavity may promote a variety of oral disease occurs, adverse prosthesis (such as a rough surface of the prosthesis) is an important factor in promoting accumulation. Studies have shown that the surface roughness of the prosthesis is to determine one of the factors of the amount of bacterial adhesion. In the clinically used metal repair materials, cobalt-chromium alloy (Co-Cr alloy) or nickel-chromium alloy (Ni-Cr alloy) because of their chemical stability, growth and reproduction of microorganisms have a certain influence. We intend to Streptococcus mutans plays a key role in understanding the formation of plaque, in different roughness crown repair material adhesion to provide a reference for clinical. Objective: to observe the impact of different roughness on adhesion of Streptococcus mutans in order to make appropriate surface roughness range. 2 observe the same roughness of cobalt-chromium alloys and nickel-chromium alloy surface Streptococcus mutans adhesion further comparison of the two alloys. Standard test methods: 1 specimen preparation (1) through the metal casting prepared by conventional methods cobalt-chromium alloy 8mm × 8mm × 1mm 40 pieces, divided into five groups, each group of eight, respectively, in accordance with: A: sandblasting grit (2 min) fine gravel (2 min) hard rubber wheels (2 min) polishing paste and velvet round (2 min), B: sandblasting grit (for 2 min) fine gravel (2 min) hard rubber wheel ( 2 min), C: sandblasting grit (2 min) fine gravel (2 min), D: sandblasting grit (for 2 min), E: sandblasting, processing each group specimens (group A polished The method is a conventional method of grinding), all procedures a completed, then the handheld surface roughness meter measured the surface roughness parameters Ra, each specimen sterilized. (2) prepared by conventional methods through the metal casting cobalt-chromium alloys and nickel-chromium alloy of the standard test piece 8mm × 8mm × 1mm each of 20, in accordance with the conventional grinding methods: sand blasting, grit (2 min), the fine gravel (2 min), a hard rubber roller (2 min), polishing paste and velvet wheel (2 min), the test piece was ground and polished, the entire program one is completed, and then the handheld surface roughness meter measured the surface roughness of the test piece The parameters Ra, sterilized. 2 with a dental adhesive material zinc polycarboxylate cements the test piece is adhered to one end of the dedicated adhesion plate. 3 bacterial adhesion assays, colony counting. 4 Statistical analysis. Results: 1 surface roughness and microbial adhesion relations: (1) different polished surface roughness Ra (x ± s): RaA = 0.296 ± 0.051 μm, RaB = 0.376 ± was 0.021 μm, RaC = 0.746 ± 0.101μm RaD = 1.420 ± 0.131μm RaE = 2.300 ± 0.141μm.RaA conventional grinding method of treatment data. By the data can be drawn from the surface roughness Ra is gradually increased, from A to E, a certain interval is formed roughness series. (2) different surface roughness bacterial adhesion amount (χ ± s CFU / ml, × 106): A: 0.155 ± 0.018, B: 0.199 ± 0.024, the C: 0.412 ± 0.031, D: 0.908 ± 0.056, E: 1.858 ± 0.054. derived from the above data the amount of bacterial adhesion increased sequentially from A to E. ① draw a correlation between the surface roughness of the sample group and the amount of bacterial adhesion by linear correlation analysis was statistically significant (P <0.01). (2) one-way ANOVA (analysis of variance) statistical method test drawn each specimen amount of bacterial adhesion between the mean overall has a very significant difference (P <0.01). Pairwise comparisons among the groups mean LSD-t found that in addition to the A group and B group differences not statistically significant (P> 0.05), and other groups, the differences were significant differences (P <0.01). 2 cobalt-chromium and nickel-chromium alloy microbial adhesion: (1) the surface roughness Ra of the polished of the two materials by conventional methods (x ± s): Ra Ni-Cr = 0.287 ± 0.045μm, Ra cobalt chromium = 0.276 ± 0.038μm, two independent samples t test between the difference was not statistically significant (P> 0.05). Can exclude the the roughness difference in the experimental results. (2) The amount of bacterial adhesion of the two materials cobalt-chromium alloy surface (x ± s, CFU / ml, × 106): nickel-chromium alloy 3.128 ± 1.020, cobalt-chromium alloy 4.704 ± 1.502, show the amount of bacterial adhesion than nickel-chromium alloy, two independent samples t test was drawn between the difference was statistically significant (P <0.05). Conclusion: In the conditions of the present experiment, drawn: (1) the surface roughness have a certain correlation with the amount of bacterial adhesion, surface roughness increases, an increase in the amount of bacterial adhesion, so craftsmen by denture should be various methods to reduce the surface roughness of the denture in order to reduce the adhesion of bacteria, thus maintaining the health of the oral tissue and prolong the service life of the prosthesis. (2) combining the data of the present experiment, drawn to the surface roughness Ra (profile arithmetic average deviation) ≤ 0.376μm, in order to meet clinical requirements. The grinding of the experimental method, derived mechanic grinding, polishing castings in accordance with conventional polishing methods logical, you can get the clinical requirements roughness. (3) cobalt-chromium alloy surface bacterial adhesion than the nickel-chromium alloy, but the reason is not recommended clinical use of nickel-chromium alloy. Repair materials will affect the growth of microorganisms and adhesion, but whether the inhibition of repair materials without damage oral strains of microorganisms balanced premise solution and restoration of plant infection and the need for more in-depth research.

Laboratory Observation of S.mutans Adhesion on Two Non-noble Metal Materials

Abstract

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