Objectives The aim of this study was to evaluate the accuracy, in terms of trueness and precision, of printed models using five different industrial and dental desktop 3D printers. Materials and methods Full-arch digital models with scanbodies of 15 patients were printed with five different 3D printers. The industrial printers were 3D system Project MJP2500 (3DS) and Objet30 OrthoDesk (Obj). The dental desktop printers were NextDent 5100 (ND), Formlabs Form 2 (FL) and Rapidshape D30 (RS). A total of 225 printed models were analysed. The printed models were digitized and compared with the reference cast model using the Control X software (Geomagic). The descriptive statistics and one-way ANOVA with the post hoc Tukey test were performed (α = 0.05). Results The one-way ANOVA for the trueness and precision of the printed model presented the best results for the 3DS, followed by ND, Obj, FL and RS (P < 0.01). In the scanbody zone, the best results were for the 3DS group, followed by Obj, ND, FL and RS (P < 0.01). Comparing the technologies, the Multijet technology used in industrial printers presented better results than the DLP and SLA technologies used in dental desktop printers (P > 0.01). Conclusions There were statistically significant differences in terms of the accuracy of the printed models, with better results for the industrial than the dental desktop 3D printers. Clinical relevance The industrial 3D printers used in dental laboratories presented better accuracy than the in-office dental desktop 3D printers, and this should be considered when the best accuracy is needed to perform final prosthetic restorations.

Purpose The aim of this randomized controlled clinical trial was to evaluate peri-implant marginal bone levels (MBLs) and soft tissue dimension changes 1 year after loading. Patients in the control group received bone-level implants, whereas in the test group, tissue-level implants with a convergent transmucosal neck were used. Material and methods MBLs were calculated by measuring the distance from the implant shoulder to the first visible bone-to-implant contact using standardized periapical digital radiographs. Baseline (day of loading) and follow-up digital models obtained with an intraoral scanner were used to quantify the changes in the peri-implant soft tissue dimensions with a best-fit algorithm. Results The difference between final and baseline MBLs showed a mean bone loss of 0.16 ± 0.01 mm in the test group (n = 15) and 0.45 ± 0.09 mm in the control group (n = 14) (p > 0.05). Soft tissue contour at the level of the gingival margin (GM) increased by 1.96 ± 2.69 mm in the test group and 0.65 ± 0.42 mm in the control group (p = 0.167). Both groups showed a coronal displacement of the gingival margin with no significant differences among them. Conclusions The present study demonstrated peri-implant hard and soft tissues stability at both implant designs with no significant differences 12 months after loading. Clinical relevance There is still insufficient scientific evidence to demonstrate the role and advantages of the convergent transmucosal neck on the behavior of the peri-implant soft and hard tissues stability compared to a straight neck in bone-level implants 12 months after loading.