Effects of different sterilization methods on 3D-printed guide plates for maxillofacial surgery and physical and chemical properties

OBJECTIVE To compare the effects of three sterilization methods on the sterilization efficacy, material strength and dimensional accuracy of 3D-printed guide plates used in maxillofacial surgery. METHODS Totally 50 actual 3D-printed guide plates that were made of MED 610 material and used for maxillofacial surgeries were randomly chosen from a specialized stomatological hospital. Additionally, 20 standard 3D-printed guide plates were made with the use of same material and method. The guide plates were randomly divided into the A-A2, B-B2, C-C2, and D-D1 groups based on sterilization methods. The group A-A2 was treated glutaraldehyde immersion sterilization, the group B-B2 was treated with pressure steam sterilization, the group C-C2 was treated with hydrogen peroxide low-temperature plasma sterilization, and the group D-D1 was taken as the blank control. The qualified rate of sterilization, dimensional accuracy and material strength of the 3D-printed guide plates were observed and compared among the different sterilization modes. RESULTS The qualified rate of sterilization of Candida albicans was 100.00% in the group B1 and the group C1, 60.00% in the group A1. The average value of root-mean-square(RMS) for evaluation of the change of dimensional accuracy was 0.03 mm in the group A, 0.06 mm in the group B, 0.04 mm in the group C, with all the variation of dimensional change in acceptable range for clinical practice(<0.2 mm). The hydrogen peroxide low-temperature plasma sterilization showed more remarkable effect on mechanical property of the 3D-printed guide plates made of MED610(Z=1.984,P=0.047). With the regard to cost effectiveness, the pressure steam sterilization showed the optimal overall performance. CONCLUSION For the maxillofacial surgery, the 3D-printed guide plates that are made of MED 610 material by PolyJet 3D printing technology and are treated with pressure steam sterilization under 121 ℃, which has the advantages of reliable sterilization and stable material, better conform to the actual requirements for clinical practice and can be taken as an optimal sterilization program.