Effects of disinfection and sterilization on the dimensional changes and mechanical properties of 3D printed surgical guides for implant therapy - pilot study.

BACKGROUND: The purpose of this research was to investigate the effects of disinfection and three different sterilization methods on the dimensional changes and mechanical properties of three-dimensional (3D) printed surgical guide for implant therapy. The objective was to assess the effects of sterilization procedures in 3D printed drill guide templates with destructive and non-destructive material testing. METHODS: Fifteen identical drill guide templates were produced using a 3D printer. The surgical guides were classified into five groups: three controls, three disinfected (4% Gigasept®, 60 min), three plasma sterilized, three autoclave sterilized (+ 1 bar, 121 °C, 20 min), and three autoclave sterilized (+ 2 bar, 134 °C, 10 min). The templates were digitalized with a Steinbichler SCAN ST 3D scanner. Length was measured under an SZX16 stereomicroscope. A scanning electron microscope was used to study the surface morphology of the drill templates. The hardness, and flexural and compressive strength were measured to assess any changes in the physical characteristics of the material caused by sterilization. The drill guide templates were also examined with a Dage XiDAT 6600 X-ray. During the X-ray examinations, the following parameters were used: 100 kV voltage, 128 AVG averaging, 0.8 W power. One-way analysis of variance (ANOVA) was used to detect the difference between groups. RESULTS: Evaluation of the hardness measurements of the various specimens shows that the hardness of the material was not changed by the plasma sterilization (p = 0.0680), steam sterilization on 121 °C (p = 0.6033) or disinfection process (p = 0.1399). The statistical analysis revealed significant difference in hardness strength of the autoclave sterilized (134 °C) specimens (p = 0.0002). There was no significant difference between the goups regarding the scanning electron microscopic and stereomicroscopic examinations. There was no significant difference regarding the X-ray visibility of the templates to the effect of the disinfection (p = 0.7844), plasma sterilization (p = 0.4091) and steam sterilization on 121 °C (p = 0.9277) and steam sterilization on 131 °C (p = 0.093). The effect of the sterilization was the same in case of both flexural and compressive strength of the material. CONCLUSIONS: Our findings indicate that plasma sterilization and steam sterilization at 121 °C were both suitable for sterilizing the tested 3D printed surgical guides.

Prosthetic rehabilitation of a patient with ectrodactyly-ectodermal dysplasia-cleft lip/palate syndrome through a hybrid workflow: A case report with 2-year follow-up.

AIM: Ectrodactyly-ectodermal dysplasia-cleft lip/palate (EEC) syndrome is a rare genetic disorder that affects ectodermal derived structures, including teeth, nails, hair, and sweat glands. Prosthetic rehabilitation of patients with EEC syndrome is essential towards improving their overall quality of life. METHODS AND RESULTS: In the case shown, a telescopic retained overdenture was made on the lower jaw based on digital impression of a patient with EEC syndrome associated with cleft lip and cleft palate. Due to the congenital anomalies and limited mouth opening, the impression was taken with intraoral scanner, and after designing the telescopes on the digital model, the primary and secondary telescopes were confectioned by selective laser sintering. CONCLUSION: Combining digital dental technology and conventional clinical prosthetic treatment methods, results in a well-functioning overdenture even in such complicated situations. The prosthodontic rehabilitation of patients with ECC helps to restore the masticatory and phonetic functions, increases the patient's self-esteem, and prevents further psychological trauma caused by hypodontia.

Trueness of five different 3D printing systems including budget- and professional-grade printers: An In vitro study.

Problem: Several types of 3D printers with different techniques and prices are available on the market. However, results in the literature are inconsistent, and there is no comprehensive agreement on the accuracy of 3D printers of different price categories for dental applications. Aim: This study aimed to investigate the accuracy of five different 3D printing systems, including a comparison of budget- and higher-end 3D printing systems, according to a standardized production and evaluation protocol. Material and methods: A maxillary reference model with prepared teeth was created using 16 half-ball markers with a diameter of 1 mm to facilitate measurements. A reference file was fabricated using five different 3D printers. The printed models were scanned and superimposed onto the original standard tesselation language (.stl) file, and digital measurements were performed to assess the 3-dimensional and linear deviations between the reference and test models. Results: After examining the entire surface of the models, we found that 3D printers using Fused filament fabrication (FFF) technology -120.2 (20.3) µm create models with high trueness but high distortion. Distortions along the z-axis were found to be the highest with the stereolithography (SLA)-type 3D printer at -153.7 (38.7) µm. For the 4-unit FPD, we found 201.9 (41.8) µm deviation with the digital light processing (DLP) printer. The largest deviation (-265.1 (55.4) µm) between the second molars was observed for the DLP printer. Between the incisor and the second molar, the best results were produced by the FFF printer with -30.5 (76.7) µm. Conclusion: Budget-friendly 3D printers are comparable to professional-grade printers in terms of precision. In general, the cost of a printing system is not a reliable indicator of its level of accuracy.