Abstract: PURPOSE: To investigate the effects of metal materials for oral fixation and restoration on magnetic resonance imaging artifacts and the health of tissues around dental implants. METHODS: A total of 153 patients undergoing fixed oral restoration were selected from May 2018 to June 2020. They were divided according to the random number table method into group A (cobalt-chromium alloy, n=31), group B (nickel-chromium alloy, n=32), group C (titanium alloy, n=28), group D (pure titanium, n=29) and group E (gold alloy, n=33). The largest area of metal crown artifacts and the number of layers of the 5 groups were compared. The probing depth(PD), modified plaque index(mPLI), modified sulcus bleeding index(mSBI) and papilla index(PI) 6 months after restoration were evaluated.The data were statistically analyzed with SPSS 22.0 software package. RESULTS: One-way ANOVA showed that the largest area of metal crown artifacts and the number of layers involved in the 5 groups had significant differences(P<0.05). Pairwise comparison showed that the largest area of metal crown artifacts, and the number of involved layers in group E were significantly lower than those in groups A, B, C, and D(P<0.05). One-way ANOVA showed that there was no significant difference in PD, mPLI, mSBI and PI among 5 groups (P>0.05). Pairwise comparison showed that there was no significant difference in PD, mPLI, mSBI and PI between group A and group B, C, D and E (P>0.05). CONCLUSIONS: The artifacts produced by metal materials for oral fixation and restoration are closely related to the types of metal materials. Among them, cobalt-chromium alloys produce the largest artifacts, and gold alloys produce the smallest artifacts. The use of metal materials for oral fixation and restoration will not affect the health of tissues around dental implants.

Key words: Oral fixation, Metal materials, Magnetic resonance imaging, Artifacts, Tissues around implants